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Suckert C, Zosel C, Schaefer M. Simultaneous TIRF imaging of subplasmalemmal Ca 2+ dynamics and granule fusions in insulin-secreting INS-1 cells reveals coexistent synchronized and asynchronous release. Cell Calcium 2024; 120:102883. [PMID: 38643716 DOI: 10.1016/j.ceca.2024.102883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 03/21/2024] [Accepted: 03/29/2024] [Indexed: 04/23/2024]
Abstract
The basal and glucose-induced insulin secretion from pancreatic beta cells is a tightly regulated process that is triggered in a Ca2+-dependent fashion and further positively modulated by substances that raise intracellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) or by certain antidiabetic drugs. In a previous study, we have temporally resolved the subplasmalemmal [Ca2+]i dynamics in beta cells that are characterized by trains of sharply delimited spikes, reaching peak values up to 5 µM. Applying total internal reflection fluorescence (TIRF) microscopy and synaptopHluorin to visualize fusion events of individual granules, we found that several fusion events can coincide within 50 to 150 ms. To test whether subplasmalemmal [Ca2+]i microdomains around single or clustered Ca2+ channels may cause a synchronized release of insulin-containing vesicles, we applied simultaneous dual-color TIRF microscopy and monitored Ca2+ fluctuations and exocytotic events in INS-1 cells at high frame rates. The results indicate that fusions can be triggered by subplasmalemmal Ca2+ spiking. This, however, does account for a minority of fusion events. About 90 %-95 % of fusion events either happen between Ca2+ spikes or incidentally overlap with subplasmalemmal Ca2+ spikes. We conclude that only a fraction of exocytotic events in glucose-induced and tolbutamide- or forskolin-enhanced insulin release from INS-1 cells is tightly coupled to Ca2+ microdomains around voltage-gated Ca2+ channels.
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Affiliation(s)
- Charlotte Suckert
- Leipzig University, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Härtelstraße 16-18, Leipzig 04107, Germany
| | - Carolin Zosel
- Leipzig University, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Härtelstraße 16-18, Leipzig 04107, Germany
| | - Michael Schaefer
- Leipzig University, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Härtelstraße 16-18, Leipzig 04107, Germany.
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2
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Deng X, Peng D, Yao Y, Huang K, Wang J, Ma Z, Fu J, Xu Y. Optogenetic therapeutic strategies for diabetes mellitus. J Diabetes 2024; 16:e13557. [PMID: 38751366 PMCID: PMC11096815 DOI: 10.1111/1753-0407.13557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 02/28/2024] [Accepted: 03/11/2024] [Indexed: 05/18/2024] Open
Abstract
Diabetes mellitus (DM) is a common chronic disease affecting humans globally. It is characterized by abnormally elevated blood glucose levels due to the failure of insulin production or reduction of insulin sensitivity and functionality. Insulin and glucagon-like peptide (GLP)-1 replenishment or improvement of insulin resistance are the two major strategies to treat diabetes. Recently, optogenetics that uses genetically encoded light-sensitive proteins to precisely control cell functions has been regarded as a novel therapeutic strategy for diabetes. Here, we summarize the latest development of optogenetics and its integration with synthetic biology approaches to produce light-responsive cells for insulin/GLP-1 production, amelioration of insulin resistance and neuromodulation of insulin secretion. In addition, we introduce the development of cell encapsulation and delivery methods and smart bioelectronic devices for the in vivo application of optogenetics-based cell therapy in diabetes. The remaining challenges for optogenetics-based cell therapy in the clinical translational study are also discussed.
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Affiliation(s)
- Xin Deng
- Department of EndocrinologyChildren's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child HealthHangzhouChina
- Department of Biomedical Engineering, MOE Key Laboratory of Biomedical Engineering, Zhejiang Provincial Key Laboratory of Cardio‐Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang Provincial Key Laboratory of Traditional Chinese Medicine for Clinical Evaluation and Translational ResearchZhejiang UniversityHangzhouChina
| | - Dandan Peng
- Department of EndocrinologyChildren's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child HealthHangzhouChina
| | - Yuanfa Yao
- Department of Biomedical Engineering, MOE Key Laboratory of Biomedical Engineering, Zhejiang Provincial Key Laboratory of Cardio‐Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang Provincial Key Laboratory of Traditional Chinese Medicine for Clinical Evaluation and Translational ResearchZhejiang UniversityHangzhouChina
| | - Ke Huang
- Department of EndocrinologyChildren's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child HealthHangzhouChina
| | - Jinling Wang
- Department of EndocrinologyChildren's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child HealthHangzhouChina
| | - Zhihao Ma
- Department of Biomedical Engineering, MOE Key Laboratory of Biomedical Engineering, Zhejiang Provincial Key Laboratory of Cardio‐Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang Provincial Key Laboratory of Traditional Chinese Medicine for Clinical Evaluation and Translational ResearchZhejiang UniversityHangzhouChina
| | - Junfen Fu
- Department of EndocrinologyChildren's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child HealthHangzhouChina
| | - Yingke Xu
- Department of EndocrinologyChildren's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child HealthHangzhouChina
- Department of Biomedical Engineering, MOE Key Laboratory of Biomedical Engineering, Zhejiang Provincial Key Laboratory of Cardio‐Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang Provincial Key Laboratory of Traditional Chinese Medicine for Clinical Evaluation and Translational ResearchZhejiang UniversityHangzhouChina
- Binjiang Institute of Zhejiang UniversityHangzhouChina
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Hardy JC, Pool EH, Bruystens JGH, Zhou X, Li Q, Zhou DR, Palay M, Tan G, Chen L, Choi JLC, Lee HN, Strack S, Wang D, Taylor SS, Mehta S, Zhang J. Molecular determinants and signaling effects of PKA RIα phase separation. Mol Cell 2024; 84:1570-1584.e7. [PMID: 38537638 PMCID: PMC11031308 DOI: 10.1016/j.molcel.2024.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 12/07/2023] [Accepted: 03/01/2024] [Indexed: 04/09/2024]
Abstract
Spatiotemporal regulation of intracellular signaling molecules, such as the 3',5'-cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA), ensures proper cellular function. Liquid-liquid phase separation (LLPS) of the ubiquitous PKA regulatory subunit RIα promotes cAMP compartmentation and signaling specificity. However, the molecular determinants of RIα LLPS remain unclear. Here, we reveal that two separate dimerization interfaces, combined with the cAMP-induced unleashing of the PKA catalytic subunit (PKA-C) from the pseudosubstrate inhibitory sequence, drive RIα condensate formation in the cytosol of mammalian cells, which is antagonized by docking to A-kinase anchoring proteins. Strikingly, we find that the RIα pseudosubstrate region is critically involved in forming a non-canonical R:C complex, which recruits active PKA-C to RIα condensates to maintain low basal PKA activity in the cytosol. Our results suggest that RIα LLPS not only facilitates cAMP compartmentation but also spatially restrains active PKA-C, thus highlighting the functional versatility of biomolecular condensates in driving signaling specificity.
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Affiliation(s)
- Julia C Hardy
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA; Shu Chien-Gene Lay Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Emily H Pool
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA; Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jessica G H Bruystens
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Xin Zhou
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Qingrong Li
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Daojia R Zhou
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA; Shu Chien-Gene Lay Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Max Palay
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA; Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Gerald Tan
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Lisa Chen
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jaclyn L C Choi
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ha Neul Lee
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stefan Strack
- Department of Pharmacology, University of Iowa, Iowa City, IA 52242, USA
| | - Dong Wang
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Susan S Taylor
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA; Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Sohum Mehta
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jin Zhang
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA; Shu Chien-Gene Lay Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA; Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA; Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, USA.
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4
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Zhu H, Ding G, Huang H. FSH regulates glucose-stimulated insulin secretion: A bell-shaped curve effect. J Diabetes 2024; 16:e13546. [PMID: 38599851 PMCID: PMC11006606 DOI: 10.1111/1753-0407.13546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 02/02/2024] [Indexed: 04/12/2024] Open
Affiliation(s)
- Hong Zhu
- Obstetrics and Gynecology HospitalInstitute of Reproduction and Development, Fudan UniversityShanghaiChina
- Research Units of Embryo Original DiseasesChinese Academy of Medical SciencesShanghaiChina
- Shanghai Key Laboratory of Reprodction and DevelopmentFudan UniversityShanghaiChina
| | - Guolian Ding
- Obstetrics and Gynecology HospitalInstitute of Reproduction and Development, Fudan UniversityShanghaiChina
- Research Units of Embryo Original DiseasesChinese Academy of Medical SciencesShanghaiChina
- Shanghai Key Laboratory of Reprodction and DevelopmentFudan UniversityShanghaiChina
| | - Hefeng Huang
- Obstetrics and Gynecology HospitalInstitute of Reproduction and Development, Fudan UniversityShanghaiChina
- Research Units of Embryo Original DiseasesChinese Academy of Medical SciencesShanghaiChina
- Shanghai Key Laboratory of Reprodction and DevelopmentFudan UniversityShanghaiChina
- Key Laboratory of Reproductive Genetics (Ministry of Education)Zhejiang University School of MedicineHangzhouChina
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5
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Guo PP, Yao XR, Xu YN, Jin X, Li Q, Yan CG, Kim NH, Li XZ. Insulin interacts with PPARγ agonists to promote bovine adipocyte differentiation. Domest Anim Endocrinol 2024; 88:106848. [PMID: 38574690 DOI: 10.1016/j.domaniend.2024.106848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 02/29/2024] [Accepted: 03/19/2024] [Indexed: 04/06/2024]
Abstract
Insulin is a potent adipogenic hormone that triggers a series of transcription factors that regulate the differentiation of preadipocytes into mature adipocytes. Ciglitazone specifically binds to peroxisome proliferator-activated receptor-γ (PPARγ), thereby promoting adipocyte differentiation. As a natural ligand of PPARγ, oleic acid (OA) can promote the translocation of PPARγ into the nucleus, regulate the expression of downstream genes, and promote adipocyte differentiation. We hypothesized that ciglitazone and oleic acid interact with insulin to enhance bovine preadipocyte differentiation. Preadipocytes were cultured 96 h in differentiation medium containing 10 mg/L insulin (I), 10 mg/L insulin + 10 µM cycloglitazone (IC), 10 mg/L insulin + 100 µM oleic acid (IO), or 10 mg/L insulin + 10 µM cycloglitazone+100 µM oleic acid (ICO). Control preadipocytes (CON) were cultured in differentiation medium (containing 5% fetal calf serum). The effects on the differentiation of Yanbian cattle preadipocytes were examined using molecular and transcriptomic techniques, including differentially expressed genes (DEGs) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis. I, IC, IO, and ICO treatments produced higher concentrations of triglycerides (TAG) and lipid droplet accumulation in preadipocytes compared with CON treatment (P < 0.05). Co-treatment of insulin and PPARγ agonists significantly increased the expression of genes involved in regulating adipogenesis and fatty acid synthesis. (P < 0.05). Differential expression analysis identified 1488, 1764, 1974 and 1368 DEGs in the I, IC, IO and ICO groups, respectively. KEGG pathway analysis revealed DEGs mainly enriched in PPAR signalling, FOXO signaling pathway and fatty acid metabolism. These results indicate that OA, as PPARγ agonist, can more effectively promote the expression of bovine lipogenesis genes and the content of TAG and adiponectin when working together with insulin, and stimulate the differentiation of bovine preadipocytes. These findings provide a basis for further screening of relevant genes and transcription factors in intramuscular fat deposition and meat quality to enhance breeding programs.
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Affiliation(s)
- Pan Pan Guo
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, PR China; Healthcare International Innovation Institute, Jiangmen 529020, PR China; Guangdong University of Technology, Guangzhou 510000, PR China; Engineering Research Centre of North-East Cold Region Beef Cattle Science & Technology Innovation, Ministry of Education, Department of Animal Science, College of Agriculture, Yanbian University, Yanji 133002, PR China
| | - Xue Rui Yao
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, PR China; Healthcare International Innovation Institute, Jiangmen 529020, PR China; Guangdong University of Technology, Guangzhou 510000, PR China
| | - Yong Nan Xu
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, PR China
| | - Xin Jin
- Engineering Research Centre of North-East Cold Region Beef Cattle Science & Technology Innovation, Ministry of Education, Department of Animal Science, College of Agriculture, Yanbian University, Yanji 133002, PR China; Laboratory Animal Center, Yanbian University, Yanji 133002, PR China
| | - Qiang Li
- Engineering Research Centre of North-East Cold Region Beef Cattle Science & Technology Innovation, Ministry of Education, Department of Animal Science, College of Agriculture, Yanbian University, Yanji 133002, PR China
| | - Chang Guo Yan
- Engineering Research Centre of North-East Cold Region Beef Cattle Science & Technology Innovation, Ministry of Education, Department of Animal Science, College of Agriculture, Yanbian University, Yanji 133002, PR China; Yanbian Hongchao Wisdom Animal Husbandry Co., LTD, Yanji 133002, PR China
| | - Nam Hyung Kim
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, PR China.
| | - Xiang Zi Li
- Engineering Research Centre of North-East Cold Region Beef Cattle Science & Technology Innovation, Ministry of Education, Department of Animal Science, College of Agriculture, Yanbian University, Yanji 133002, PR China.
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Li XJ, Suo P, Wang YN, Zou L, Nie XL, Zhao YY, Miao H. Arachidonic acid metabolism as a therapeutic target in AKI-to-CKD transition. Front Pharmacol 2024; 15:1365802. [PMID: 38523633 PMCID: PMC10957658 DOI: 10.3389/fphar.2024.1365802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 02/06/2024] [Indexed: 03/26/2024] Open
Abstract
Arachidonic acid (AA) is a main component of cell membrane lipids. AA is mainly metabolized by three enzymes: cyclooxygenase (COX), lipoxygenase (LOX) and cytochrome P450 (CYP450). Esterified AA is hydrolysed by phospholipase A2 into a free form that is further metabolized by COX, LOX and CYP450 to a wide range of bioactive mediators, including prostaglandins, lipoxins, thromboxanes, leukotrienes, hydroxyeicosatetraenoic acids and epoxyeicosatrienoic acids. Increased mitochondrial oxidative stress is considered to be a central mechanism in the pathophysiology of the kidney. Along with increased oxidative stress, apoptosis, inflammation and tissue fibrosis drive the progressive loss of kidney function, affecting the glomerular filtration barrier and the tubulointerstitium. Recent studies have shown that AA and its active derivative eicosanoids play important roles in the regulation of physiological kidney function and the pathogenesis of kidney disease. These factors are potentially novel biomarkers, especially in the context of their involvement in inflammatory processes and oxidative stress. In this review, we introduce the three main metabolic pathways of AA and discuss the molecular mechanisms by which these pathways affect the progression of acute kidney injury (AKI), diabetic nephropathy (DN) and renal cell carcinoma (RCC). This review may provide new therapeutic targets for the identification of AKI to CKD continuum.
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Affiliation(s)
- Xiao-Jun Li
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
- Department of Nephrology, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Ping Suo
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Yan-Ni Wang
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Liang Zou
- School of Food and Bioengineering, Chengdu University, Chengdu, Sichuan, China
| | - Xiao-Li Nie
- Department of Nephrology, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Ying-Yong Zhao
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Hua Miao
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
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7
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Jiang C, Zhao J, Zhang Y, Zhu X. Role of EPAC1 in chronic pain. Biochem Biophys Rep 2024; 37:101645. [PMID: 38304575 PMCID: PMC10832381 DOI: 10.1016/j.bbrep.2024.101645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 02/03/2024] Open
Abstract
Chronic pain usually lasts over three months and commonly occurs in chronic diseases (cancer, arthritis, and diabetes), injuries (herniated discs, torn ligaments), and many major pain disorders (neuropathic pain, fibromyalgia, chronic headaches). Unfortunately, there is currently a lack of effective treatments to help people with chronic pain to achieve complete relief. Therefore,it is particularly important to understand the mechanism of chronic pain and find new therapeutic targets. The exchange protein directly activated by cyclic adenosine monophosphate(cAMP) (EPAC) has been recognized for its functions in nerve regeneration, stimulating insulin release, controlling vascular pressure, and controlling other metabolic activities. In recent years, many studies have found that the subtype of EPAC, EPAC1 is involved in the regulation of neuroinflammation and plays a crucial role in the regulation of pain, which is expected to become a new therapeutic target for chronic pain. This article reviews the major contributions of EPAC1 in chronic pain.
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Affiliation(s)
- Chenlu Jiang
- Department of Anesthesiology, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong, 226001, China
- Medical School of Nantong University, Nantong, 226001, China
| | - Jiacheng Zhao
- Department of Anesthesiology, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong, 226001, China
- Medical School of Nantong University, Nantong, 226001, China
| | - Yihang Zhang
- Medical School of Nantong University, Nantong, 226001, China
| | - Xiang Zhu
- Department of Anesthesiology, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong, 226001, China
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Turbitt J, Moffett RC, Brennan L, Johnson PRV, Flatt PR, McClenaghan NH, Tarasov AI. Molecular determinants and intracellular targets of taurine signalling in pancreatic islet β-cells. Acta Physiol (Oxf) 2024; 240:e14101. [PMID: 38243723 DOI: 10.1111/apha.14101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 12/26/2023] [Accepted: 01/08/2024] [Indexed: 01/21/2024]
Abstract
AIM Despite its abundance in pancreatic islets of Langerhans and proven antihyperglycemic effects, the impact of the essential amino acid, taurine, on islet β-cell biology has not yet received due consideration, which prompted the current studies exploring the molecular selectivity of taurine import into β-cells and its acute and chronic intracellular interactions. METHODS The molecular aspects of taurine transport were probed by exposing the clonal pancreatic BRIN BD11 β-cells and primary mouse and human islets to a range of the homologs of the amino acid (assayed at 2-20 mM), using the hormone release and imaging of intracellular signals as surrogate read-outs. Known secretagogues were employed to profile the interaction of taurine with acute and chronic intracellular signals. RESULTS Taurine transporter TauT was expressed in the islet β-cells, with the transport of taurine and homologs having a weak sulfonate specificity but significant sensitivity to the molecular weight of the transporter. Taurine, hypotaurine, homotaurine, and β-alanine enhanced insulin secretion in a glucose-dependent manner, an action potentiated by cytosolic Ca2+ and cAMP. Acute and chronic β-cell insulinotropic effects of taurine were highly sensitive to co-agonism with GLP-1, forskolin, tolbutamide, and membrane depolarization, with an unanticipated indifference to the activation of PKC and CCK8 receptors. Pre-culturing with GLP-1 or KATP channel inhibitors sensitized or, respectively, desensitized β-cells to the acute taurine stimulus. CONCLUSION Together, these data demonstrate the pathways whereby taurine exhibits a range of beneficial effects on insulin secretion and β-cell function, consistent with the antidiabetic potential of its dietary low-dose supplementation.
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Affiliation(s)
- Julie Turbitt
- School of Biomedical Sciences, Ulster University, Coleraine, UK
| | | | - Lorraine Brennan
- UCD Institute of Food and Health, UCD School of Agriculture and Food Science, University College Dublin, Dublin 4, Republic of Ireland
- UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Republic of Ireland
| | - Paul R V Johnson
- Nuffield Department of Surgical Sciences, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
- Oxford Biomedical Research Centre (OxBRC), Oxford, UK
| | - Peter R Flatt
- School of Biomedical Sciences, Ulster University, Coleraine, UK
| | - Neville H McClenaghan
- School of Biomedical Sciences, Ulster University, Coleraine, UK
- Department of Life Sciences, Atlantic Technological University, Sligo, Republic of Ireland
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Hardy JC, Pool EH, Bruystens JGH, Zhou X, Li Q, Zhou DR, Palay M, Tan G, Chen L, Choi JLC, Lee HN, Strack S, Wang D, Taylor SS, Mehta S, Zhang J. Molecular Determinants and Signaling Effects of PKA RIα Phase Separation. bioRxiv 2023:2023.12.10.570836. [PMID: 38168176 PMCID: PMC10760030 DOI: 10.1101/2023.12.10.570836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Spatiotemporal regulation of intracellular signaling molecules, such as the 3',5'-cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA), ensures the specific execution of various cellular functions. Liquid-liquid phase separation (LLPS) of the ubiquitously expressed PKA regulatory subunit RIα was recently identified as a major driver of cAMP compartmentation and signaling specificity. However, the molecular determinants of RIα LLPS remain unclear. Here, we reveal that two separate dimerization interfaces combined with the cAMP-induced release of the PKA catalytic subunit (PKA-C) from the pseudosubstrate inhibitory sequence are required to drive RIα condensate formation in cytosol, which is antagonized by docking to A-kinase anchoring proteins. Strikingly, we find that the RIα pseudosubstrate region is critically involved in the formation of a non-canonical R:C complex, which serves to maintain low basal PKA activity in the cytosol by enabling the recruitment of active PKA-C to RIα condensates. Our results suggest that RIα LLPS not only facilitates cAMP compartmentation but also spatially restrains active PKA-C, thus highlighting the functional versatility of biomolecular condensates in driving signaling specificity.
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10
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Yammine L, Picatoste B, Abdullah N, Leahey RA, Johnson EF, Gómez-Banoy N, Rosselot C, Wen J, Hossain T, Goncalves MD, Lo JC, Garcia-Ocaña A, McGraw TE. Spatiotemporal regulation of GIPR signaling impacts glucose homeostasis as revealed in studies of a common GIPR variant. Mol Metab 2023; 78:101831. [PMID: 37925022 PMCID: PMC10665708 DOI: 10.1016/j.molmet.2023.101831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 11/06/2023] Open
Abstract
OBJECTIVE Glucose-dependent insulinotropic polypeptide (GIP) has a role in controlling postprandial metabolic tone. In humans, a GIP receptor (GIPR) variant (Q354, rs1800437) is associated with a lower body mass index (BMI) and increased risk for Type 2 Diabetes. To better understand the impacts of GIPR-Q354 on metabolism, it is necessary to study it in an isogeneic background to the predominant GIPR isoform, E354. To accomplish this objective, we used CRISPR-CAS9 editing to generate mouse models of GIPR-Q354 and GIPR-E354. Here we characterize the metabolic effects of GIPR-Q354 variant in a mouse model (GIPR-Q350). METHODS We generated the GIPR-Q350 mice for in vivo studies of metabolic impact of the variant. We isolated pancreatic islets from GIPR-Q350 mice to study insulin secretion ex vivo. We used a β-cell cell line to understand the impact of the GIPR-Q354 variant on the receptor traffic. RESULTS We found that female GIPR-Q350 mice are leaner than littermate controls, and male GIPR-Q350 mice are resistant to diet-induced obesity, in line with the association of the variant with reduced BMI in humans. GIPR-Q350 mice of both sexes are more glucose tolerant and exhibit an increased sensitivity to GIP. Postprandial GIP levels are reduced in GIPR-Q350 mice, revealing feedback regulation that balances the increased sensitivity of GIP target tissues to secretion of GIP from intestinal endocrine cells. The increased GIP sensitivity is recapitulated ex vivo during glucose stimulated insulin secretion assays in islets. Generation of cAMP in islets downstream of GIPR activation is not affected by the Q354 substitution. However, post-activation traffic of GIPR-Q354 variant in β-cells is altered, characterized by enhanced intracellular dwell time and increased localization to the Trans-Golgi Network (TGN). CONCLUSIONS Our data link altered intracellular traffic of the GIPR-Q354 variant with GIP control of metabolism. We propose that this change in spatiotemporal signaling underlies the physiologic effects of GIPR-Q350/4 and GIPR-E350/4 in mice and humans. These findings contribute to a more complete understanding of the impact of GIPR-Q354 variant on glucose homeostasis that could perhaps be leveraged to enhance pharmacologic targeting of GIPR for the treatment of metabolic disease.
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Affiliation(s)
- Lucie Yammine
- Department of Biochemistry, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Belén Picatoste
- Department of Biochemistry, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Nazish Abdullah
- Department of Biochemistry, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Rosemary A Leahey
- Department of Biochemistry, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Emma F Johnson
- Department of Biochemistry, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Nicolás Gómez-Banoy
- Weill Center for Metabolic Health and Division of Cardiology, Department of Medicine, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Carolina Rosselot
- Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Jennifer Wen
- Department of Biochemistry, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Tahmina Hossain
- Department of Biochemistry, Weill Cornell Medical College, New York, NY, 10065, USA
| | | | - James C Lo
- Weill Center for Metabolic Health and Division of Cardiology, Department of Medicine, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Adolfo Garcia-Ocaña
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Timothy E McGraw
- Department of Biochemistry, Weill Cornell Medical College, New York, NY, 10065, USA; Weill Center for Metabolic Health and Division of Cardiology, Department of Medicine, Weill Cornell Medicine, New York, NY, 10021, USA; Department of Cardiothoracic Surgery, Weill Cornell Medical College, New York, NY, 10065, USA.
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11
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Cheng Y, Zhu H, Ren J, Wu HY, Yu JE, Jin LY, Pang HY, Pan HT, Luo SS, Yan J, Dong KX, Ye LY, Zhou CL, Pan JX, Meng ZX, Yu T, Jin L, Lin XH, Wu YT, Yang HB, Liu XM, Sheng JZ, Ding GL, Huang HF. Follicle-stimulating hormone orchestrates glucose-stimulated insulin secretion of pancreatic islets. Nat Commun 2023; 14:6991. [PMID: 37914684 PMCID: PMC10620214 DOI: 10.1038/s41467-023-42801-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 10/20/2023] [Indexed: 11/03/2023] Open
Abstract
Follicle-stimulating hormone (FSH) is involved in mammalian reproduction via binding to FSH receptor (FSHR). However, several studies have found that FSH and FSHR play important roles in extragonadal tissue. Here, we identified the expression of FSHR in human and mouse pancreatic islet β-cells. Blocking FSH signaling by Fshr knock-out led to impaired glucose tolerance owing to decreased insulin secretion, while high FSH levels caused insufficient insulin secretion as well. In vitro, we found that FSH orchestrated glucose-stimulated insulin secretion (GSIS) in a bell curve manner. Mechanistically, FSH primarily activates Gαs via FSHR, promoting the cAMP/protein kinase A (PKA) and calcium pathways to stimulate GSIS, whereas high FSH levels could activate Gαi to inhibit the cAMP/PKA pathway and the amplified effect on GSIS. Our results reveal the role of FSH in regulating pancreatic islet insulin secretion and provide avenues for future clinical investigation and therapeutic strategies for postmenopausal diabetes.
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Affiliation(s)
- Yi Cheng
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China
- Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hong Zhu
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China
- Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Jun Ren
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hai-Yan Wu
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jia-En Yu
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Lu-Yang Jin
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hai-Yan Pang
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hai-Tao Pan
- Shaoxing Maternity and Child Health Care Hospital, Shaoxing, China
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Si-Si Luo
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
| | - Jing Yan
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China
- Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Kai-Xuan Dong
- Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
- Departments of Obstetrics and Gynecology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Long-Yun Ye
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Centre, Shanghai, China
| | - Cheng-Liang Zhou
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
| | - Jie-Xue Pan
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China
- Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Zhuo-Xian Meng
- Key Laboratory of Disease Proteomics of Zhejiang Province, Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Ting Yu
- Key Laboratory of Disease Proteomics of Zhejiang Province, Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Li Jin
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China
- Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Xian-Hua Lin
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China
- Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Yan-Ting Wu
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China
- Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Hong-Bo Yang
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China
- Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Xin-Mei Liu
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China
- Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Jian-Zhong Sheng
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.
- Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China.
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.
- Department of Obstetrics and Gynecology, International Institutes of Medicine, the Fourth Affiliated Hospital of Zhejiang University School of Medicine, Yiwu, China.
| | - Guo-Lian Ding
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.
- Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China.
| | - He-Feng Huang
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.
- Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China.
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China.
- Department of Obstetrics and Gynecology, International Institutes of Medicine, the Fourth Affiliated Hospital of Zhejiang University School of Medicine, Yiwu, China.
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12
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Emfinger CH, Clark LE, Yandell B, Schueler KL, Simonett SP, Stapleton DS, Mitok KA, Merrins MJ, Keller MP, Attie AD. Novel regulators of islet function identified from genetic variation in mouse islet Ca 2+ oscillations. eLife 2023; 12:RP88189. [PMID: 37787501 PMCID: PMC10547476 DOI: 10.7554/elife.88189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023] Open
Abstract
Insufficient insulin secretion to meet metabolic demand results in diabetes. The intracellular flux of Ca2+ into β-cells triggers insulin release. Since genetics strongly influences variation in islet secretory responses, we surveyed islet Ca2+ dynamics in eight genetically diverse mouse strains. We found high strain variation in response to four conditions: (1) 8 mM glucose; (2) 8 mM glucose plus amino acids; (3) 8 mM glucose, amino acids, plus 10 nM glucose-dependent insulinotropic polypeptide (GIP); and (4) 2 mM glucose. These stimuli interrogate β-cell function, α- to β-cell signaling, and incretin responses. We then correlated components of the Ca2+ waveforms to islet protein abundances in the same strains used for the Ca2+ measurements. To focus on proteins relevant to human islet function, we identified human orthologues of correlated mouse proteins that are proximal to glycemic-associated single-nucleotide polymorphisms in human genome-wide association studies. Several orthologues have previously been shown to regulate insulin secretion (e.g. ABCC8, PCSK1, and GCK), supporting our mouse-to-human integration as a discovery platform. By integrating these data, we nominate novel regulators of islet Ca2+ oscillations and insulin secretion with potential relevance for human islet function. We also provide a resource for identifying appropriate mouse strains in which to study these regulators.
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Affiliation(s)
| | - Lauren E Clark
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Brian Yandell
- Department of Statistics, University of Wisconsin-MadisonMadisonUnited States
| | - Kathryn L Schueler
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Shane P Simonett
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Donnie S Stapleton
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Kelly A Mitok
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Matthew J Merrins
- Department of Medicine, Division of Endocrinology, University of Wisconsin-MadisonMadisonUnited States
- William S. Middleton Memorial Veterans HospitalMadisonUnited States
| | - Mark P Keller
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Alan D Attie
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
- Department of Medicine, Division of Endocrinology, University of Wisconsin-MadisonMadisonUnited States
- Department of Chemistry, University of Wisconsin-MadisonMadisonUnited States
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13
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Bohuslavova R, Fabriciova V, Smolik O, Lebrón-Mora L, Abaffy P, Benesova S, Zucha D, Valihrach L, Berkova Z, Saudek F, Pavlinkova G. NEUROD1 reinforces endocrine cell fate acquisition in pancreatic development. Nat Commun 2023; 14:5554. [PMID: 37689751 PMCID: PMC10492842 DOI: 10.1038/s41467-023-41306-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 08/30/2023] [Indexed: 09/11/2023] Open
Abstract
NEUROD1 is a transcription factor that helps maintain a mature phenotype of pancreatic β cells. Disruption of Neurod1 during pancreatic development causes severe neonatal diabetes; however, the exact role of NEUROD1 in the differentiation programs of endocrine cells is unknown. Here, we report a crucial role of the NEUROD1 regulatory network in endocrine lineage commitment and differentiation. Mechanistically, transcriptome and chromatin landscape analyses demonstrate that Neurod1 inactivation triggers a downregulation of endocrine differentiation transcription factors and upregulation of non-endocrine genes within the Neurod1-deficient endocrine cell population, disturbing endocrine identity acquisition. Neurod1 deficiency altered the H3K27me3 histone modification pattern in promoter regions of differentially expressed genes, which resulted in gene regulatory network changes in the differentiation pathway of endocrine cells, compromising endocrine cell potential, differentiation, and functional properties.
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Affiliation(s)
- Romana Bohuslavova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Valeria Fabriciova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Ondrej Smolik
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Laura Lebrón-Mora
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Pavel Abaffy
- Laboratory of Gene Expression, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Sarka Benesova
- Laboratory of Gene Expression, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Daniel Zucha
- Laboratory of Gene Expression, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Lukas Valihrach
- Laboratory of Gene Expression, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Zuzana Berkova
- Diabetes Centre, Experimental Medicine Centre, Institute for Clinical and Experimental Medicine, 14021, Prague, Czechia
| | - Frantisek Saudek
- Diabetes Centre, Experimental Medicine Centre, Institute for Clinical and Experimental Medicine, 14021, Prague, Czechia
| | - Gabriela Pavlinkova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia.
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14
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Skelin Klemen M, Dolenšek J, Križančić Bombek L, Pohorec V, Gosak M, Slak Rupnik M, Stožer A. The effect of forskolin and the role of Epac2A during activation, activity, and deactivation of beta cell networks. Front Endocrinol (Lausanne) 2023; 14:1225486. [PMID: 37701894 PMCID: PMC10494243 DOI: 10.3389/fendo.2023.1225486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/08/2023] [Indexed: 09/14/2023] Open
Abstract
Beta cells couple stimulation by glucose with insulin secretion and impairments in this coupling play a central role in diabetes mellitus. Cyclic adenosine monophosphate (cAMP) amplifies stimulus-secretion coupling via protein kinase A and guanine nucleotide exchange protein 2 (Epac2A). With the present research, we aimed to clarify the influence of cAMP-elevating diterpene forskolin on cytoplasmic calcium dynamics and intercellular network activity, which are two of the crucial elements of normal beta cell stimulus-secretion coupling, and the role of Epac2A under normal and stimulated conditions. To this end, we performed functional multicellular calcium imaging of beta cells in mouse pancreas tissue slices after stimulation with glucose and forskolin in wild-type and Epac2A knock-out mice. Forskolin evoked calcium signals in otherwise substimulatory glucose and beta cells from Epac2A knock-out mice displayed a faster activation. During the plateau phase, beta cells from Epac2A knock-out mice displayed a slightly higher active time in response to glucose compared with wild-type littermates, and stimulation with forskolin increased the active time via an increase in oscillation frequency and a decrease in oscillation duration in both Epac2A knock-out and wild-type mice. Functional network properties during stimulation with glucose did not differ in Epac2A knock-out mice, but the presence of Epac2A was crucial for the protective effect of stimulation with forskolin in preventing a decline in beta cell functional connectivity with time. Finally, stimulation with forskolin prolonged beta cell activity during deactivation, especially in Epac2A knock-out mice.
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Affiliation(s)
- Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | | | - Viljem Pohorec
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
- Alma Mater Europaea, European Center Maribor, Maribor, Slovenia
| | - Marjan Slak Rupnik
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Alma Mater Europaea, European Center Maribor, Maribor, Slovenia
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
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Knuth ER, Foster HR, Jin E, Merrins MJ. Leucine suppresses glucagon secretion from pancreatic islets by directly modulating α-cell cAMP. bioRxiv 2023:2023.07.31.551113. [PMID: 37577685 PMCID: PMC10418066 DOI: 10.1101/2023.07.31.551113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Objective Pancreatic islets are nutrient sensors that regulate organismal blood glucose homeostasis. Glucagon release from the pancreatic α-cell is important under fasted, fed, and hypoglycemic conditions, yet metabolic regulation of α-cells remains poorly understood. Here, we identified a previously unexplored role for physiological levels of leucine, which is classically regarded as a β-cell fuel, in the intrinsic regulation of α-cell glucagon release. Methods GcgCreERT:CAMPER and GcgCreERT:GCaMP6s mice were generated to perform dynamic, high-throughput functional measurements of α-cell cAMP and Ca2+ within the intact islet. Islet perifusion assays were used for simultaneous, time-resolved measurements of glucagon and insulin release from mouse and human islets. The effects of leucine were compared with glucose and the mitochondrial fuels 2-aminobicyclo(2,2,1)heptane-2-carboxylic acid (BCH, non-metabolized leucine analog that activates glutamate dehydrogenase), α-ketoisocaproate (KIC, leucine metabolite), and methyl-succinate (complex II fuel). CYN154806 (Sstr2 antagonist), diazoxide (KATP activator, which prevents Ca2+-dependent exocytosis from α, β, and δ-cells), and dispersed α-cells were used to inhibit islet paracrine signaling and identify α-cell intrinsic effects. Results Mimicking the effect of glucose, leucine strongly suppressed amino acid-stimulated glucagon secretion. Mechanistically, leucine dose-dependently reduced α-cell cAMP at physiological concentrations, with an IC50 of 57, 440, and 1162 μM at 2, 6, and 10 mM glucose, without affecting α-cell Ca2+. Leucine also reduced α-cell cAMP in islets treated with Sstr2 antagonist or diazoxide, as well as dispersed α-cells, indicating an α-cell intrinsic effect. The effect of leucine was matched by KIC and the glutamate dehydrogenase activator BCH, but not methyl-succinate, indicating a dependence on mitochondrial anaplerosis. Glucose, which stimulates anaplerosis via pyruvate carboxylase, had the same suppressive effect on α-cell cAMP but with lower potency. Similarly to mouse islets, leucine suppressed glucagon secretion from human islets under hypoglycemic conditions. Conclusions These findings highlight an important role for physiological levels of leucine in the metabolic regulation of α-cell cAMP and glucagon secretion. Leucine functions primarily through an α-cell intrinsic effect that is dependent on glutamate dehydrogenase, in addition to the well-established α-cell regulation by β/δ-cell paracrine signaling. Our results suggest that mitochondrial anaplerosis-cataplerosis facilitates the glucagonostatic effect of both leucine and glucose, which cooperatively suppress α-cell tone by reducing cAMP.
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Affiliation(s)
- Emily R. Knuth
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Hannah R. Foster
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Erli Jin
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Matthew J. Merrins
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53705, USA
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
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16
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Zhou S, Liu J, Tan L, Wang Y, Li J, Wang Y, Ding C, Long H. Changes in metabolites in raw and wine processed Corni Fructus combination metabolomics with network analysis focusing on potential hypoglycemic effects. Front Pharmacol 2023; 14:1173747. [PMID: 37608891 PMCID: PMC10440738 DOI: 10.3389/fphar.2023.1173747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 07/25/2023] [Indexed: 08/24/2023] Open
Abstract
Introduction: Corni Fructus (CF) is a Chinese herbal medicine used for medicinal and dietary purposes. It is available commercially in two main forms: raw CF (unprocessed CF) and wine-processed CF. Clinical observations have indicated that wine-processed CF exhibits superior hypoglycemic activity compared to its raw counterpart. However, the mechanisms responsible for this improvement are not well understood. Methods: To address this gap in knowledge, we conducted metabolomics analysis using ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (UPLC-QTOF-MS) to compare the chemical composition of raw CF and wine-processed CF. Subsequently, network analysis, along with immunofluorescence assays, was employed to elucidate the potential targets and mechanisms underlying the hypoglycemic effects of metabolites in CF. Results: Our results revealed significant compositional differences between raw CF and wine-processed CF, identifying 34 potential markers for distinguishing between the two forms of CF. Notably, wine processing led to a marked decrease in iridoid glycosides and flavonoid glycosides, which are abundant in raw CF. Network analysis predictions provided clues that eight compounds might serve as hypoglycemic metabolites of CF, and glucokinase (GCK) and adenylate cyclase (ADCYs) were speculated as possible key targets responsible for the hypoglycemic effects of CF. Immunofluorescence assays confirmed that oleanolic acid and ursolic acid, two bioactive compounds present in CF, significantly upregulated the expression of GCK and ADCYs in the HepG2 cell model. Discussion: These findings support the notion that CF exerted hypoglycemic activity via multiple components and targets, shedding light on the impact of processing methods on the chemical composition and hypoglycemic activity of Chinese herbal medicine.
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Affiliation(s)
- Siqian Zhou
- Center for Medical Research and Innovation, The First Hospital of Hunan University of Chinese Medicine, Changsha, China
- Hunan University of Chinese Medicine, Changsha, China
| | - Jian Liu
- Center for Medical Research and Innovation, The First Hospital of Hunan University of Chinese Medicine, Changsha, China
| | - Leihong Tan
- Department of Pharmacy, The Second Hospital of Hunan University of Chinese Medicine, Changsha, China
| | - Yikun Wang
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Jing Li
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha, China
| | - Yajing Wang
- Hunan University of Chinese Medicine, Changsha, China
| | | | - Hongping Long
- Center for Medical Research and Innovation, The First Hospital of Hunan University of Chinese Medicine, Changsha, China
- Hunan University of Chinese Medicine, Changsha, China
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17
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Wang L, Meng Q, Wang H, Huang X, Yu C, Yin G, Wang D, Jiang H, Huang Z. Luman regulates the activity of the LHCGR promoter. Res Vet Sci 2023; 161:132-137. [PMID: 37384971 DOI: 10.1016/j.rvsc.2023.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 06/15/2023] [Accepted: 06/19/2023] [Indexed: 07/01/2023]
Abstract
Testosterone in male mammals is mainly secreted by testicular Leydig cells, and its secretion process is regulated by the hypothalamic-pituitary-gonadal axis. After receiving the luteinizing hormone (LH) stimulus signal, the lutropin/choriogonadotropin receptor (LHCGR) on the Leydig cell membrane transfers the signal into the cell and finally increases the secretion of testosterone by upregulating the expression of steroid hormone synthase. In previous experiments, we found that interfering with the expression of the Luman protein can significantly increase testosterone secretion in MLTC-1 cells. In this experiment, we found that knockdown of Luman in MLTC-1 cells significantly increased the concentration of cAMP and upregulated the expression of AC and LHCGR. Moreover, an analysis of the activity of the LHCGR promoter by a dual luciferase reporter system showed that knockdown of Luman increased the activity of the LHCGR promoter. Therefore, we believe that knockdown of Luman increased the activity of the LHCGR promoter and upregulated the expression of LHCGR, thereby increasing the concentration of intracellular cAMP and ultimately leading to an increase of testosterone secretion by MLTC-1 cells.
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Affiliation(s)
- Lei Wang
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China.
| | - Qingrui Meng
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Hailun Wang
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Xiaoyu Huang
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Chunchen Yu
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Guangwen Yin
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Dengfeng Wang
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Heji Jiang
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Zhijian Huang
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China.
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18
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Utami AR, Maksum IP, Deawati Y. Berberine and Its Study as an Antidiabetic Compound. Biology (Basel) 2023; 12:973. [PMID: 37508403 PMCID: PMC10376565 DOI: 10.3390/biology12070973] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 06/13/2023] [Accepted: 06/15/2023] [Indexed: 07/30/2023]
Abstract
Diabetes mellitus (DM) is a metabolic disorder that causes hyperglycemia conditions and leads to various chronic complications that causes death. The prevalence of diabetes is predicted to continue to increase, and with the high toxicity levels of current diabetes drugs, the exploration of natural compounds as alternative diabetes treatment has been widely carried out, one of which is berberine. Berberine and several other alkaloid compounds, including some of its derivatives, have shown many bioactivities, such as neuraminidase and hepatoprotective activity. Berberine also exhibits antidiabetic activity. As an antidiabetic compound, berberine is known to reduce blood glucose levels, increase insulin secretion, and weaken glucose tolerance and insulin resistance by activating the AMPK pathway. Apart from being an antidiabetic compound, berberine also exhibits various other activities such as being anti-adipogenic, anti-hyperlipidemic, anti-inflammatory, and antioxidant. Many studies have been conducted on berberine, but its exact mechanism still needs to be clarified and requires further investigation. This review will discuss berberine and its mechanism as a natural compound with various activities, mainly as an antidiabetic.
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Affiliation(s)
- Ayudiah Rizki Utami
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang 45363, Indonesia
| | - Iman Permana Maksum
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang 45363, Indonesia
| | - Yusi Deawati
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang 45363, Indonesia
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19
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Ramanadham S, Turk J, Bhatnagar S. Noncanonical Regulation of cAMP-Dependent Insulin Secretion and Its Implications in Type 2 Diabetes. Compr Physiol 2023; 13:5023-5049. [PMID: 37358504 PMCID: PMC10809800 DOI: 10.1002/cphy.c220031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Impaired glucose tolerance (IGT) and β-cell dysfunction in insulin resistance associated with obesity lead to type 2 diabetes (T2D). Glucose-stimulated insulin secretion (GSIS) from β-cells occurs via a canonical pathway that involves glucose metabolism, ATP generation, inactivation of K ATP channels, plasma membrane depolarization, and increases in cytosolic concentrations of [Ca 2+ ] c . However, optimal insulin secretion requires amplification of GSIS by increases in cyclic adenosine monophosphate (cAMP) signaling. The cAMP effectors protein kinase A (PKA) and exchange factor activated by cyclic-AMP (Epac) regulate membrane depolarization, gene expression, and trafficking and fusion of insulin granules to the plasma membrane for amplifying GSIS. The widely recognized lipid signaling generated within β-cells by the β-isoform of Ca 2+ -independent phospholipase A 2 enzyme (iPLA 2 β) participates in cAMP-stimulated insulin secretion (cSIS). Recent work has identified the role of a G-protein coupled receptor (GPCR) activated signaling by the complement 1q like-3 (C1ql3) secreted protein in inhibiting cSIS. In the IGT state, cSIS is attenuated, and the β-cell function is reduced. Interestingly, while β-cell-specific deletion of iPLA 2 β reduces cAMP-mediated amplification of GSIS, the loss of iPLA 2 β in macrophages (MØ) confers protection against the development of glucose intolerance associated with diet-induced obesity (DIO). In this article, we discuss canonical (glucose and cAMP) and novel noncanonical (iPLA 2 β and C1ql3) pathways and how they may affect β-cell (dys)function in the context of impaired glucose intolerance associated with obesity and T2D. In conclusion, we provide a perspective that in IGT states, targeting noncanonical pathways along with canonical pathways could be a more comprehensive approach for restoring β-cell function in T2D. © 2023 American Physiological Society. Compr Physiol 13:5023-5049, 2023.
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Affiliation(s)
- Sasanka Ramanadham
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Alabama, USA
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Alabama, USA
| | - John Turk
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Sushant Bhatnagar
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Alabama, USA
- Department of Medicine, University of Alabama at Birmingham, Alabama, USA
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20
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Zhou J, Shi Y, Yang C, Lu S, Zhao L, Liu X, Zhou D, Luo L, Yin Z. γ-glutamylcysteine alleviates insulin resistance and hepatic steatosis by regulating adenylate cyclase and IGF-1R/IRS1/PI3K/Akt signaling pathways. J Nutr Biochem 2023:109404. [PMID: 37311491 DOI: 10.1016/j.jnutbio.2023.109404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 06/02/2023] [Accepted: 06/07/2023] [Indexed: 06/15/2023]
Abstract
Type 2 diabetes mellitus (T2DM), a complex metabolism disease, which was characterized by metabolic disorders including hyperglycemia, has become a major health problem due to the increasing prevalence worldwide. γ-glutamylcysteine (γ-GC) as an immediate precursor of glutathione (GSH) was originally used for the treatment of sepsis, inflammation bowel disease, and senescence. Here, we evaluated the capacity of γ-GC on diabetes-related metabolic parameters in db/db mice and insulin resistance (IR) amelioration in cells induced by palmitic acid (PA). Our data suggested that γ-GC treatment decreased body weight, reduced adipose tissue size, ameliorated ectopic fat deposition in liver, increased the GSH content in liver, improved glucose control and other diabetes-related metabolic parameters in vivo. Moreover, in vitro experiments showed that γ-GC could maintain the balance of free fatty acids (FFAs) and glucose uptake through regulating the translocation of CD36 and GLUT4 from cytoplasm to plasma membrane. Furthermore, our finding also provided evidence that γ-GC could activate Akt not only via adenylate cyclase (AC)/cAMP/PI3K signaling pathway, but also via IGF-1R/IRS1/PI3K signaling pathway to improve IR and hepatic steatosis. Blocking either of two signaling pathways could not activate Akt activation induced by γ-GC. This unique characteristic ensures the important role of γ-GC in glucose metabolism. Collectively, these results suggested that γ-GC could serve as a candidate dipeptide for the treatment of T2DM and related chronic diabetic complications via activating AC and IGF-1R/IRS1/PI3K/Akt signaling pathways to regulate CD36 and GLUT4 trafficking.
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Affiliation(s)
- Jinyi Zhou
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China
| | - Yingying Shi
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China
| | - Chen Yang
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China
| | - Shuai Lu
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China
| | - Lishuang Zhao
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China
| | - Xianli Liu
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China
| | - Da Zhou
- Department of Gastroenterology and Hepatology, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China.
| | - Lan Luo
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
| | - Zhimin Yin
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China.
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21
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Yavuz A, Aydin MA, Ugur K, Aydin S, Senol A, Baykus Y, Deniz R, Sahin İ, Yalcin MH, Gencer BT, Deniz YK, Ustebay S, Karagoz ZK, Emre E, Aydin S. Betatrophin, elabela, asprosin, glucagon and subfatin peptides in breast tissue, blood and milk in gestational diabetes. Biotech Histochem 2023; 98:243-254. [PMID: 36825397 DOI: 10.1080/10520295.2023.2176546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
We investigated the presence of asprosin (ASP), betatrophin, elabela (ELA), glucagon and subfatin (SUB) in the milk of mothers with gestational diabetes mellitus (GDM) and compared their levels with blood levels. We also investigated whether these peptides are synthesized by the breast. We investigated 12 volunteer mothers with GDM and 14 pregnant non-GDM control mothers. The peptides were measured using ELISA and their tissue localization was determined using immunohistochemistry. Breast milk contains ASP, betatrophin, ELA, glucagon and SUB. The amount of the peptides ranged from highest to the lowest in colostrum, transitional milk and mature milk. The amount of peptides in the milk was greater than for blood. The peptides, except for ELA, were increased in milk and blood by GDM. Betatrophin and ELA are synthesized in the connective tissue of the breast. ASP, glucagon and SUB are synthesized in the alveolar tissue of the breast. These peptides in breast milk may contribute to the development of the gastrointestinal tract of newborns and infants.
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Affiliation(s)
- Adem Yavuz
- Department of Obstetrics and Gynecology, Nigde Omer Halis Demir Research and Education Hospital, Nigde, Turkiye
| | - Mustafa Ata Aydin
- Medical Student, School of Medicine, Gazi University, Ankara, Turkiye
| | - Kader Ugur
- Department of Internal Medicine (Endocrinology and Metabolism Diseases), School of Medicine, Firat University, Elazig, Turkiye
| | - Suna Aydin
- Department of Cardiovascular Surgery, Fethi Sekin City Hospital, Elazig, Turkiye
- Department of Anatomy, School of Medicine, Firat University, Elazig, Turkiye
- Department of Histology and Embryology, School of Veterinary Medicine, Firat University, Elazig, Turkiye
| | - Arzu Senol
- Department of Enfection Disease, Fethi Sekin City Hospital, Elazig, Turkiye
| | - Yakup Baykus
- Department of Obstetrics and Gynecology, Bandirma 17 Eylul Univerity, Balikesir, Turkiye
| | - Rulin Deniz
- Department of Obstetrics and Gynecology, Bandirma 17 Eylul Univerity, Balikesir, Turkiye
| | - İbrahim Sahin
- Department of Medical Biochemistry and Clinical Biochemistry, (Firat Hormones Research Group), Medical School, Firat University, Elazig, Turkiye
- Department of Medical Biology, School of Medicine, Erzincan Binali Yildirim University, Erzincan, Turkiye
| | - Mehmet Hanifi Yalcin
- Department of Histology and Embryology, School of Veterinary Medicine, Firat University, Elazig, Turkiye
| | - Berrin Tarakci Gencer
- Department of Histology and Embryology, School of Veterinary Medicine, Firat University, Elazig, Turkiye
| | - Yaprak Kandemir Deniz
- Department of Obstetrics and Gynecology, Antalya Medicalpark Hospital Complex, Antalya, Turkiye
| | - Sefer Ustebay
- Department of Pediatrics, Bandirma 17 Eylul Univerity, Balikesir, Turkiye
| | - Zuhal Karaca Karagoz
- Department of Internal Medicine (Endocrinology and Metabolism Diseases), Fethi Sekin City Hospital, Elazig, Turkiye
| | - Elif Emre
- Department of Anatomy, School of Medicine, Firat University, Elazig, Turkiye
| | - Suleyman Aydin
- Department of Medical Biochemistry and Clinical Biochemistry, (Firat Hormones Research Group), Medical School, Firat University, Elazig, Turkiye
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22
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Slika H, Mansour H, Nasser SA, Shaito A, Kobeissy F, Orekhov AN, Pintus G, Eid AH. Epac as a tractable therapeutic target. Eur J Pharmacol 2023; 945:175645. [PMID: 36894048 DOI: 10.1016/j.ejphar.2023.175645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 02/26/2023] [Accepted: 03/06/2023] [Indexed: 03/09/2023]
Abstract
In 1957, cyclic adenosine monophosphate (cAMP) was identified as the first secondary messenger, and the first signaling cascade discovered was the cAMP-protein kinase A (PKA) pathway. Since then, cAMP has received increasing attention given its multitude of actions. Not long ago, a new cAMP effector named exchange protein directly activated by cAMP (Epac) emerged as a critical mediator of cAMP's actions. Epac mediates a plethora of pathophysiologic processes and contributes to the pathogenesis of several diseases such as cancer, cardiovascular disease, diabetes, lung fibrosis, neurological disorders, and others. These findings strongly underscore the potential of Epac as a tractable therapeutic target. In this context, Epac modulators seem to possess unique characteristics and advantages and hold the promise of providing more efficacious treatments for a wide array of diseases. This paper provides an in-depth dissection and analysis of Epac structure, distribution, subcellular compartmentalization, and signaling mechanisms. We elaborate on how these characteristics can be utilized to design specific, efficient, and safe Epac agonists and antagonists that can be incorporated into future pharmacotherapeutics. In addition, we provide a detailed portfolio for specific Epac modulators highlighting their discovery, advantages, potential concerns, and utilization in the context of clinical disease entities.
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Affiliation(s)
- Hasan Slika
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, P.O. Box 11-0236, Lebanon.
| | - Hadi Mansour
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, P.O. Box 11-0236, Lebanon.
| | | | - Abdullah Shaito
- Biomedical Research Center, Qatar University, Doha, P.O. Box: 2713, Qatar.
| | - Firas Kobeissy
- Department of Neurobiology and Neuroscience, Morehouse School of Medicine, Atlanta, Georgia, USA.
| | - Alexander N Orekhov
- Laboratory of Cellular and Molecular Pathology of Cardiovascular System, Institute of Human Morphology, 3 Tsyurupa Street, Moscow, 117418, Russia; Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, 8 Baltiiskaya Street, Moscow, 125315, Russia; Institute for Atherosclerosis Research, Skolkovo Innovative Center, Osennyaya Street 4-1-207, Moscow, 121609, Russia.
| | - Gianfranco Pintus
- Department of Biomedical Sciences, University of Sassari, 07100, Sassari, Italy.
| | - Ali H Eid
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, P.O. Box 2713, Qatar.
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23
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Guilherme A, Rowland LA, Wang H, Czech MP. The adipocyte supersystem of insulin and cAMP signaling. Trends Cell Biol 2023; 33:340-354. [PMID: 35989245 PMCID: PMC10339226 DOI: 10.1016/j.tcb.2022.07.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/27/2022] [Accepted: 07/28/2022] [Indexed: 01/28/2023]
Abstract
Adipose tissue signals to brain, liver, and muscles to control whole body metabolism through secreted lipid and protein factors as well as neurotransmission, but the mechanisms involved are incompletely understood. Adipocytes sequester triglyceride (TG) in fed conditions stimulated by insulin, while in fasting catecholamines trigger TG hydrolysis, releasing glycerol and fatty acids (FAs). These antagonistic hormone actions result in part from insulin's ability to inhibit cAMP levels generated through such G-protein-coupled receptors as catecholamine-activated β-adrenergic receptors. Consistent with these antagonistic signaling modes, acute actions of catecholamines cause insulin resistance. Yet, paradoxically, chronically activating adipocytes by catecholamines cause increased glucose tolerance, as does insulin. Recent results have helped to unravel this conundrum by revealing enhanced complexities of these hormones' signaling networks, including identification of unexpected common signaling nodes between these canonically antagonistic hormones.
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Affiliation(s)
- Adilson Guilherme
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA.
| | - Leslie A Rowland
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Hui Wang
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Michael P Czech
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA.
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24
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Ferri G, Musikant D, Edreira MM. Host Cell Rap1b mediates cAMP-dependent invasion by Trypanosoma cruzi. PLoS Negl Trop Dis 2023; 17:e0011191. [PMID: 36897926 PMCID: PMC10032529 DOI: 10.1371/journal.pntd.0011191] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 03/22/2023] [Accepted: 02/22/2023] [Indexed: 03/11/2023] Open
Abstract
Trypanosoma cruzi cAMP-mediated invasion has long been described, however, the detailed mechanism of action of the pathway activated by this cyclic nucleotide still remains unknown. We have recently demonstrated a crucial role for Epac in the cAMP-mediated invasion of the host cell. In this work, we gathered evidence indicating that the cAMP/Epac pathway is activated in different cells lines. In accordance, data collected from pull-down experiments designed to identify only the active form of Rap1b (Rap1b-GTP), and infection assays using cells transfected with a constitutively active mutant of Rap1b (Rap1b-G12V), strongly suggest the participation of Rap1b as mediator of the pathway. In addition to the activation of this small GTPase, fluorescence microscopy allowed us to demonstrate the relocalization of Rap1b to the entry site of the parasite. Moreover, phospho-mimetic and non-phosphorylable mutants of Rap1b were used to demonstrate a PKA-dependent antagonistic effect on the pathway, by phosphorylation of Rap1b, and potentially of Epac. Finally, Western Blot analysis was used to determine the involvement of the MEK/ERK signalling downstream of cAMP/Epac/Rap1b-mediated invasion.
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Affiliation(s)
- Gabriel Ferri
- CONICET-Universidad de Buenos Aires, IQUIBICEN, Ciudad de Buenos Aires, Argentina
- Laboratorio de Biología Molecular de Trypanosomas, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos, Ciudad de Buenos Aires, Argentina
| | - Daniel Musikant
- CONICET-Universidad de Buenos Aires, IQUIBICEN, Ciudad de Buenos Aires, Argentina
- Laboratorio de Biología Molecular de Trypanosomas, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos, Ciudad de Buenos Aires, Argentina
| | - Martin M Edreira
- CONICET-Universidad de Buenos Aires, IQUIBICEN, Ciudad de Buenos Aires, Argentina
- Laboratorio de Biología Molecular de Trypanosomas, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos, Ciudad de Buenos Aires, Argentina
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25
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Ast J, Nasteska D, Fine NHF, Nieves DJ, Koszegi Z, Lanoiselée Y, Cuozzo F, Viloria K, Bacon A, Luu NT, Newsome PN, Calebiro D, Owen DM, Broichhagen J, Hodson DJ. Revealing the tissue-level complexity of endogenous glucagon-like peptide-1 receptor expression and signaling. Nat Commun 2023; 14:301. [PMID: 36653347 DOI: 10.1038/s41467-022-35716-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 12/21/2022] [Indexed: 01/19/2023] Open
Abstract
The glucagon-like peptide-1 receptor (GLP1R) is a class B G protein-coupled receptor (GPCR) involved in glucose homeostasis and food intake. GLP1R agonists (GLP1RA) are widely used in the treatment of diabetes and obesity, yet visualizing the endogenous localization, organization and dynamics of a GPCR has so far remained out of reach. In the present study, we generate mice harboring an enzyme self-label genome-edited into the endogenous Glp1r locus. We also rationally design and test various fluorescent dyes, spanning cyan to far-red wavelengths, for labeling performance in tissue. By combining these technologies, we show that endogenous GLP1R can be specifically and sensitively detected in primary tissue using multiple colors. Longitudinal analysis of GLP1R dynamics reveals heterogeneous recruitment of neighboring cell subpopulations into signaling and trafficking, with differences observed between GLP1RA classes and dual agonists. At the nanoscopic level, GLP1Rs are found to possess higher organization, undergoing GLP1RA-dependent membrane diffusion. Together, these results show the utility of enzyme self-labels for visualization and interrogation of endogenous proteins, and provide insight into the biology of a class B GPCR in primary cells and tissue.
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26
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Signorile A, De Rasmo D. Mitochondrial Complex I, a Possible Sensible Site of cAMP Pathway in Aging. Antioxidants (Basel) 2023; 12:antiox12020221. [PMID: 36829783 PMCID: PMC9951957 DOI: 10.3390/antiox12020221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
In mammals during aging, reactive oxygen species (ROS), produced by the mitochondrial respiratory chain, cause oxidative damage of macromolecules leading to respiratory chain dysfunction, which in turn increases ROS mitochondrial production. Many efforts have been made to understand the role of oxidative stress in aging and age-related diseases. The complex I of the mitochondrial respiratory chain is the major source of ROS production and its dysfunctions have been associated with several forms of neurodegeneration, other common human diseases and aging. Complex I-ROS production and complex I content have been proposed as the major determinants for longevity. The cAMP signal has a role in the regulation of complex I activity and the decrease of ROS production. In the last years, an increasing number of studies have attempted to activate cAMP signaling to treat age-related diseases associated with mitochondrial dysfunctions and ROS production. This idea comes from a long-line of studies showing a main role of cAMP signal in the memory consolidation mechanism and in the regulation of mitochondrial functions. Here, we discuss several evidences on the possible connection between complex I and cAMP pathway in the aging process.
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Affiliation(s)
- Anna Signorile
- Department of Translational Biomedicine and Neuroscience, University of Bari Aldo Moro, 70124 Bari, Italy
| | - Domenico De Rasmo
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnology (IBIOM), National Research Council (CNR), 70126 Bari, Italy
- Correspondence: ; Tel.: +39-080-544-8516
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27
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Pixner T, Stummer N, Schneider AM, Lukas A, Gramlinger K, Julian V, Thivel D, Mörwald K, Mangge H, Dalus C, Aigner E, Furthner D, Weghuber D, Maruszczak K. The relationship between glucose and the liver-alpha cell axis - A systematic review. Front Endocrinol (Lausanne) 2023; 13:1061682. [PMID: 36686477 PMCID: PMC9849557 DOI: 10.3389/fendo.2022.1061682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 12/13/2022] [Indexed: 01/06/2023] Open
Abstract
Until recently, glucagon was considered a mere antagonist to insulin, protecting the body from hypoglycemia. This notion changed with the discovery of the liver-alpha cell axis (LACA) as a feedback loop. The LACA describes how glucagon secretion and pancreatic alpha cell proliferation are stimulated by circulating amino acids. Glucagon in turn leads to an upregulation of amino acid metabolism and ureagenesis in the liver. Several increasingly common diseases (e.g., non-alcoholic fatty liver disease, type 2 diabetes, obesity) disrupt this feedback loop. It is important for clinicians and researchers alike to understand the liver-alpha cell axis and the metabolic sequelae of these diseases. While most of previous studies have focused on fasting concentrations of glucagon and amino acids, there is limited knowledge of their dynamics after glucose administration. The authors of this systematic review applied PRISMA guidelines and conducted PubMed searches to provide results of 8078 articles (screened and if relevant, studied in full). This systematic review aims to provide better insight into the LACA and its mediators (amino acids and glucagon), focusing on the relationship between glucose and the LACA in adult and pediatric subjects.
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Affiliation(s)
- Thomas Pixner
- Department of Pediatric and Adolescent Medicine, Salzkammergutklinikum Voecklabruck, Voecklabruck, Austria
- Obesity Research Unit, Paracelsus Medical University, Salzburg, Austria
| | - Nathalie Stummer
- Obesity Research Unit, Paracelsus Medical University, Salzburg, Austria
- Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Anna Maria Schneider
- Obesity Research Unit, Paracelsus Medical University, Salzburg, Austria
- Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Andreas Lukas
- Department of Pediatric and Adolescent Medicine, Salzkammergutklinikum Voecklabruck, Voecklabruck, Austria
- Obesity Research Unit, Paracelsus Medical University, Salzburg, Austria
| | - Karin Gramlinger
- Department of Pediatric and Adolescent Medicine, Salzkammergutklinikum Voecklabruck, Voecklabruck, Austria
| | - Valérie Julian
- Department of Sport Medicine and Functional Explorations, Diet and Musculoskeletal Health Team, Human Nutrition Research Center (CRNH), INRA, University Hospital of Clermont-Ferrand, University of Clermont Auvergne, Clermont-Ferrand, France
| | - David Thivel
- Laboratory of Metabolic Adaptations to Exercise under Physiological and Pathological Conditions (AME2P), University of Clermont Auvergne, Clermont-Ferrand, France
| | - Katharina Mörwald
- Obesity Research Unit, Paracelsus Medical University, Salzburg, Austria
- Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Harald Mangge
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | - Christopher Dalus
- Obesity Research Unit, Paracelsus Medical University, Salzburg, Austria
- Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Elmar Aigner
- Obesity Research Unit, Paracelsus Medical University, Salzburg, Austria
- First Department of Medicine, Paracelsus Medical University, Salzburg, Austria
| | - Dieter Furthner
- Department of Pediatric and Adolescent Medicine, Salzkammergutklinikum Voecklabruck, Voecklabruck, Austria
- Obesity Research Unit, Paracelsus Medical University, Salzburg, Austria
| | - Daniel Weghuber
- Obesity Research Unit, Paracelsus Medical University, Salzburg, Austria
- Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Katharina Maruszczak
- Obesity Research Unit, Paracelsus Medical University, Salzburg, Austria
- Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
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Zhang X, Lv H, Mei J, Ji B, Huang S, Li X. The Potential Role of R4 Regulators of G Protein Signaling (RGS) Proteins in Type 2 Diabetes Mellitus. Cells 2022; 11. [PMID: 36497154 DOI: 10.3390/cells11233897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/26/2022] [Accepted: 11/30/2022] [Indexed: 12/05/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a complex and heterogeneous disease that primarily results from impaired insulin secretion or insulin resistance (IR). G protein-coupled receptors (GPCRs) are proposed as therapeutic targets for T2DM. GPCRs transduce signals via the Gα protein, playing an integral role in insulin secretion and IR. The regulators of G protein signaling (RGS) family proteins can bind to Gα proteins and function as GTPase-activating proteins (GAP) to accelerate GTP hydrolysis, thereby terminating Gα protein signaling. Thus, RGS proteins determine the size and duration of cellular responses to GPCR stimulation. RGSs are becoming popular targeting sites for modulating the signaling of GPCRs and related diseases. The R4 subfamily is the largest RGS family. This review will summarize the research progress on the mechanisms of R4 RGS subfamily proteins in insulin secretion and insulin resistance and analyze their potential value in the treatment of T2DM.
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Deng X, Wang C, Xia Y, Yuan G. Protein Targeting to Glycogen (PTG): A Promising Player in Glucose and Lipid Metabolism. Biomolecules 2022; 12. [PMID: 36551183 DOI: 10.3390/biom12121755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/16/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022] Open
Abstract
Protein phosphorylation and dephosphorylation are widely considered to be the key regulatory factors of cell function, and are often referred to as "molecular switches" in the regulation of cell metabolic processes. A large number of studies have shown that the phosphorylation/dephosphorylation of related signal molecules plays a key role in the regulation of liver glucose and lipid metabolism. As a new therapeutic strategy for metabolic diseases, the potential of using inhibitor-based therapies to fight diabetes has gained scientific momentum. PTG, a protein phosphatase, also known as glycogen targeting protein, is a member of the protein phosphatase 1 (PP1) family. It can play a role by catalyzing the dephosphorylation of phosphorylated protein molecules, especially regulating many aspects of glucose and lipid metabolism. In this review, we briefly summarize the role of PTG in glucose and lipid metabolism, and update its role in metabolic regulation, with special attention to glucose homeostasis and lipid metabolism.
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Hali M, Wadzinski BE, Kowluru A. Alpha4 contributes to the dysfunction of the pancreatic beta cell under metabolic stress. Mol Cell Endocrinol 2022; 557:111754. [PMID: 35987388 PMCID: PMC9620510 DOI: 10.1016/j.mce.2022.111754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 08/10/2022] [Accepted: 08/12/2022] [Indexed: 11/30/2022]
Abstract
The current study examined the roles of Alpha4, a non-canonical subunit of protein phosphatase 2A, in the regulation of acute (insulin secretion) and chronic (cell dysfunction) effects of glucose in pancreatic beta cells. Alpha4 is expressed in human islets, rat islets and INS-1832/13 cells. Incubation of INS-1832/13 cells and rat islets with high glucose (HG) significantly increased the expression of Alpha4. C2-Ceramide, a biologically active sphingolipid, also increased the expression of Alpha4 in INS-1832/13 cells and rat islets. Subcellular distribution studies of Alpha4 in low glucose (LG) and HG exposed INS-1832/13 cells revealed that it is predominantly cytosolic, and its expression is significantly increased in the non-nuclear/cytosolic fractions in cells exposed to HG. siRNA-mediated knockdown of Alpha4 exerted minimal effects on glucose- or KCl-induced insulin secretion. siRNA-mediated deletion of Alpha4 significantly increased p38MAPK and JNK1/2 phosphorylation under LG conditions, comparable to the degree seen under HG conditions. Paradoxically, a significant potentiation of HG-induced p38MAPK and JNK2 phosphorylation was noted following Alpha4 deletion. HG-induced CHOP expression (ER stress marker) and caspase-3 activation were markedly attenuated in cells following Alpha4 knockdown. Deletion of Alpha4 in INS-1832/13 cells prevented HG-induced loss in the expression of Connexin36, a gap junction channel protein, which has been implicated in normal beta cell function. Lastly, depletion of endogenous Alpha4 significantly reduced HG-induced cell death in INS-1832/13 cells. Based on these findings we conclude that Alpha4 contributes to HG-induced metabolic dysfunction of the islet beta cell.
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Affiliation(s)
- Mirabela Hali
- Biomedical Research Service, John D. Dingell VA Medical Center, Detroit, MI, USA; Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, USA
| | - Brian E Wadzinski
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Anjaneyulu Kowluru
- Biomedical Research Service, John D. Dingell VA Medical Center, Detroit, MI, USA; Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, USA.
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Dickerson MT, Dadi PK, Zaborska KE, Nakhe AY, Schaub CM, Dobson JR, Wright NM, Lynch JC, Scott CF, Robinson LD, Jacobson DA. G i/o protein-coupled receptor inhibition of beta-cell electrical excitability and insulin secretion depends on Na +/K + ATPase activation. Nat Commun 2022; 13:6461. [PMID: 36309517 PMCID: PMC9617941 DOI: 10.1038/s41467-022-34166-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 10/17/2022] [Indexed: 12/25/2022] Open
Abstract
Gi/o-coupled somatostatin or α2-adrenergic receptor activation stimulated β-cell NKA activity, resulting in islet Ca2+ fluctuations. Furthermore, intra-islet paracrine activation of β-cell Gi/o-GPCRs and NKAs by δ-cell somatostatin secretion slowed Ca2+ oscillations, which decreased insulin secretion. β-cell membrane potential hyperpolarization resulting from Gi/o-GPCR activation was dependent on NKA phosphorylation by Src tyrosine kinases. Whereas, β-cell NKA function was inhibited by cAMP-dependent PKA activity. These data reveal that NKA-mediated β-cell membrane potential hyperpolarization is the primary and conserved mechanism for Gi/o-GPCR control of electrical excitability, Ca2+ handling, and insulin secretion.
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Affiliation(s)
- Matthew T Dickerson
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Prasanna K Dadi
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Karolina E Zaborska
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Arya Y Nakhe
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Charles M Schaub
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Jordyn R Dobson
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Nicole M Wright
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Joshua C Lynch
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Claire F Scott
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Logan D Robinson
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - David A Jacobson
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA.
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Zhang X, Kupczyk E, Schmitt-Kopplin P, Mueller C. Current and future approaches for in vitro hit discovery in diabetes mellitus. Drug Discov Today 2022; 27:103331. [PMID: 35926826 DOI: 10.1016/j.drudis.2022.07.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 06/10/2022] [Accepted: 07/26/2022] [Indexed: 12/15/2022]
Abstract
Type 2 diabetes mellitus (T2DM) is a serious public health problem. In this review, we discuss current and promising future drugs, targets, in vitro assays and emerging omics technologies in T2DM. Importantly, we open the perspective to image-based high-content screening (HCS), with the focus of combining it with metabolomics or lipidomics. HCS has become a strong technology in phenotypic screens because it allows comprehensive screening for the cell-modulatory activity of small molecules. Metabolomics and lipidomics screen for perturbations at the molecular level. The combination of these data-intensive comprehensive technologies is enabled by the rapid development of artificial intelligence. It promises a deep cellular and molecular phenotyping directly linked to chemical information about the applied drug candidates or complex mixtures.
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Affiliation(s)
- Xin Zhang
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany
| | - Erwin Kupczyk
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany; Comprehensive Foodomics Platform, Chair of Analytical Food Chemistry, TUM School of Life Sciences, Technical University of Munich, Maximus-von-Imhof-Forum 2, 85354 Freising, Germany
| | - Philippe Schmitt-Kopplin
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany; Comprehensive Foodomics Platform, Chair of Analytical Food Chemistry, TUM School of Life Sciences, Technical University of Munich, Maximus-von-Imhof-Forum 2, 85354 Freising, Germany.
| | - Constanze Mueller
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany.
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Atla G, Bonàs-Guarch S, Cuenca-Ardura M, Beucher A, Crouch DJM, Garcia-Hurtado J, Moran I, Irimia M, Prasad RB, Gloyn AL, Marselli L, Suleiman M, Berney T, de Koning EJP, Kerr-Conte J, Pattou F, Todd JA, Piemonti L, Ferrer J. Genetic regulation of RNA splicing in human pancreatic islets. Genome Biol 2022; 23:196. [PMID: 36109769 PMCID: PMC9479353 DOI: 10.1186/s13059-022-02757-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 08/23/2022] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Non-coding genetic variants that influence gene transcription in pancreatic islets play a major role in the susceptibility to type 2 diabetes (T2D), and likely also contribute to type 1 diabetes (T1D) risk. For many loci, however, the mechanisms through which non-coding variants influence diabetes susceptibility are unknown. RESULTS We examine splicing QTLs (sQTLs) in pancreatic islets from 399 human donors and observe that common genetic variation has a widespread influence on the splicing of genes with established roles in islet biology and diabetes. In parallel, we profile expression QTLs (eQTLs) and use transcriptome-wide association as well as genetic co-localization studies to assign islet sQTLs or eQTLs to T2D and T1D susceptibility signals, many of which lack candidate effector genes. This analysis reveals biologically plausible mechanisms, including the association of T2D with an sQTL that creates a nonsense isoform in ERO1B, a regulator of ER-stress and proinsulin biosynthesis. The expanded list of T2D risk effector genes reveals overrepresented pathways, including regulators of G-protein-mediated cAMP production. The analysis of sQTLs also reveals candidate effector genes for T1D susceptibility such as DCLRE1B, a senescence regulator, and lncRNA MEG3. CONCLUSIONS These data expose widespread effects of common genetic variants on RNA splicing in pancreatic islets. The results support a role for splicing variation in diabetes susceptibility, and offer a new set of genetic targets with potential therapeutic benefit.
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Affiliation(s)
- Goutham Atla
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Centro de Investigación Biomédica en red Diabetes y enfermedades metabólicas asociadas (CIBERDEM), Barcelona, Spain
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Silvia Bonàs-Guarch
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain.
- Centro de Investigación Biomédica en red Diabetes y enfermedades metabólicas asociadas (CIBERDEM), Barcelona, Spain.
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK.
| | - Mirabai Cuenca-Ardura
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Centro de Investigación Biomédica en red Diabetes y enfermedades metabólicas asociadas (CIBERDEM), Barcelona, Spain
| | - Anthony Beucher
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Centro de Investigación Biomédica en red Diabetes y enfermedades metabólicas asociadas (CIBERDEM), Barcelona, Spain
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Daniel J M Crouch
- JDRF/Wellcome Diabetes and Inflammation Laboratory, Wellcome Centre for Human Genetics, Nuffield Department of Medicine, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Javier Garcia-Hurtado
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Centro de Investigación Biomédica en red Diabetes y enfermedades metabólicas asociadas (CIBERDEM), Barcelona, Spain
| | - Ignasi Moran
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
- Present Address: Life Sciences Department, Barcelona Supercomputing Center (BSC), 08034, Barcelona, Spain
| | - Manuel Irimia
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Rashmi B Prasad
- Lund University Diabetes Centre, Clinical Research Center, Malmö, Sweden
- Department of Clinical Sciences in Malmö, Lund University, Malmö, Sweden
| | - Anna L Gloyn
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Department of Pediatrics, Division of Endocrinology, Stanford School of Medicine, Stanford, CA, USA
| | - Lorella Marselli
- Department of Clinical and Experimental Medicine, AOUP Cisanello University Hospital, University of Pisa, Pisa, Italy
| | - Mara Suleiman
- Department of Clinical and Experimental Medicine, AOUP Cisanello University Hospital, University of Pisa, Pisa, Italy
| | - Thierry Berney
- Cell Isolation and Transplantation Center, University of Geneva, Geneva, Switzerland
| | - Eelco J P de Koning
- Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands
- Hubrecht Institute/KNAW, Utrecht, the Netherlands
| | - Julie Kerr-Conte
- University of Lille, Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Hospitalier Universitaire de Lille (CHU Lille), Institute Pasteur Lille, U1190 -European Genomic Institute for Diabetes (EGID), F59000, Lille, France
| | - Francois Pattou
- University of Lille, Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Hospitalier Universitaire de Lille (CHU Lille), Institute Pasteur Lille, U1190 -European Genomic Institute for Diabetes (EGID), F59000, Lille, France
| | - John A Todd
- JDRF/Wellcome Diabetes and Inflammation Laboratory, Wellcome Centre for Human Genetics, Nuffield Department of Medicine, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Lorenzo Piemonti
- Diabetes Research Institute, IRCCS Ospedale San Raffaele and Università Vita-Salute San Raffaele, Milan, Italy
| | - Jorge Ferrer
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain.
- Centro de Investigación Biomédica en red Diabetes y enfermedades metabólicas asociadas (CIBERDEM), Barcelona, Spain.
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK.
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Liu X, Vickstrom CR, Yu H, Liu S, Snarrenberg ST, Friedman V, Mu L, Chen B, Kelly TJ, Baker DA, Liu QS. Epac2 in midbrain dopamine neurons contributes to cocaine reinforcement via facilitation of dopamine release. eLife 2022; 11:80747. [PMID: 35993549 PMCID: PMC9436413 DOI: 10.7554/elife.80747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 08/21/2022] [Indexed: 11/21/2022] Open
Abstract
Repeated exposure to drugs of abuse results in an upregulation of cAMP signaling in the mesolimbic dopamine system, a molecular adaptation thought to be critically involved in the development of drug dependence. Exchange protein directly activated by cAMP (Epac2) is a major cAMP effector abundantly expressed in the brain. However, it remains unknown whether Epac2 contributes to cocaine reinforcement. Here, we report that Epac2 in the mesolimbic dopamine system promotes cocaine reinforcement via enhancement of dopamine release. Conditional knockout of Epac2 from midbrain dopamine neurons (Epac2-cKO) and the selective Epac2 inhibitor ESI-05 decreased cocaine self-administration in mice under both fixed-ratio and progressive-ratio reinforcement schedules and across a broad range of cocaine doses. In addition, Epac2-cKO led to reduced evoked dopamine release, whereas Epac2 agonism robustly enhanced dopamine release in the nucleus accumbens in vitro. This mechanism is central to the behavioral effects of Epac2 disruption, as chemogenetic stimulation of ventral tegmental area (VTA) dopamine neurons via deschloroclozapine (DCZ)-induced activation of Gs-DREADD increased dopamine release and reversed the impairment of cocaine self-administration in Epac2-cKO mice. Conversely, chemogenetic inhibition of VTA dopamine neurons with Gi-DREADD reduced dopamine release and cocaine self-administration in wild-type mice. Epac2-mediated enhancement of dopamine release may therefore represent a novel and powerful mechanism that contributes to cocaine reinforcement.
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Affiliation(s)
- Xiaojie Liu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Casey R Vickstrom
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Hao Yu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Shuai Liu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Shana Terai Snarrenberg
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Vladislav Friedman
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Lianwei Mu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Bixuan Chen
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Thomas J Kelly
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - David A Baker
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Qing-Song Liu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
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Aslanoglou D, Bertera S, Friggeri L, Sánchez-Soto M, Lee J, Xue X, Logan RW, Lane JR, Yechoor VK, McCormick PJ, Meiler J, Free RB, Sibley DR, Bottino R, Freyberg Z. Dual pancreatic adrenergic and dopaminergic signaling as a therapeutic target of bromocriptine. iScience 2022; 25:104771. [PMID: 35982797 PMCID: PMC9379584 DOI: 10.1016/j.isci.2022.104771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 06/10/2022] [Accepted: 07/11/2022] [Indexed: 11/23/2022] Open
Abstract
Bromocriptine is approved as a diabetes therapy, yet its therapeutic mechanisms remain unclear. Though bromocriptine's actions have been mainly attributed to the stimulation of brain dopamine D2 receptors (D2R), bromocriptine also targets the pancreas. Here, we employ bromocriptine as a tool to elucidate the roles of catecholamine signaling in regulating pancreatic hormone secretion. In β-cells, bromocriptine acts on D2R and α2A-adrenergic receptor (α2A-AR) to reduce glucose-stimulated insulin secretion (GSIS). Moreover, in α-cells, bromocriptine acts via D2R to reduce glucagon secretion. α2A-AR activation by bromocriptine recruits an ensemble of G proteins with no β-arrestin2 recruitment. In contrast, D2R recruits G proteins and β-arrestin2 upon bromocriptine stimulation, demonstrating receptor-specific signaling. Docking studies reveal distinct bromocriptine binding to α2A-AR versus D2R, providing a structural basis for bromocriptine's dual actions on β-cell α2A-AR and D2R. Together, joint dopaminergic and adrenergic receptor actions on α-cell and β-cell hormone release provide a new therapeutic mechanism to improve dysglycemia.
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Affiliation(s)
- Despoina Aslanoglou
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Suzanne Bertera
- Institute of Cellular Therapeutics, Allegheny Health Network Research Institute, Allegheny Health Network, Pittsburgh, PA, USA
| | - Laura Friggeri
- Department of Chemistry, Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
| | - Marta Sánchez-Soto
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Jeongkyung Lee
- Diabetes and Beta Cell Biology Center, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xiangning Xue
- Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ryan W. Logan
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA
| | - J. Robert Lane
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham, UK
- Centre of Membrane Protein and Receptors, Universities of Birmingham and Nottingham, Nottingham, UK
| | - Vijay K. Yechoor
- Diabetes and Beta Cell Biology Center, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Peter J. McCormick
- Centre for Endocrinology, William Harvey Research Institute, Bart’s and the London School of Medicine and Dentistry, Queen Mary, University of London, London, UK
| | - Jens Meiler
- Department of Chemistry, Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
- Institute for Drug Discovery, Leipzig University Medical School, Leipzig, Germany
| | - R. Benjamin Free
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - David R. Sibley
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Rita Bottino
- Institute of Cellular Therapeutics, Allegheny Health Network Research Institute, Allegheny Health Network, Pittsburgh, PA, USA
- Imagine Pharma, Pittsburgh, PA, USA
| | - Zachary Freyberg
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Cell Biology, University of Pittsburgh, PA, USA
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36
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Merino B, Casanueva-Álvarez E, Quesada I, González-Casimiro CM, Fernández-Díaz CM, Postigo-Casado T, Leissring MA, Kaestner KH, Perdomo G, Cózar-Castellano I. Insulin-degrading enzyme ablation in mouse pancreatic alpha cells triggers cell proliferation, hyperplasia and glucagon secretion dysregulation. Diabetologia 2022; 65:1375-1389. [PMID: 35652923 PMCID: PMC9283140 DOI: 10.1007/s00125-022-05729-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 03/11/2022] [Indexed: 01/01/2023]
Abstract
AIMS/HYPOTHESIS Type 2 diabetes is characterised by hyperglucagonaemia and perturbed function of pancreatic glucagon-secreting alpha cells but the molecular mechanisms contributing to these phenotypes are poorly understood. Insulin-degrading enzyme (IDE) is present within all islet cells, mostly in alpha cells, in both mice and humans. Furthermore, IDE can degrade glucagon as well as insulin, suggesting that IDE may play an important role in alpha cell function in vivo. METHODS We have generated and characterised a novel mouse model with alpha cell-specific deletion of Ide, the A-IDE-KO mouse line. Glucose metabolism and glucagon secretion in vivo was characterised; isolated islets were tested for glucagon and insulin secretion; alpha cell mass, alpha cell proliferation and α-synuclein levels were determined in pancreas sections by immunostaining. RESULTS Targeted deletion of Ide exclusively in alpha cells triggers hyperglucagonaemia and alpha cell hyperplasia, resulting in elevated constitutive glucagon secretion. The hyperglucagonaemia is attributable in part to dysregulation of glucagon secretion, specifically an impaired ability of IDE-deficient alpha cells to suppress glucagon release in the presence of high glucose or insulin. IDE deficiency also leads to α-synuclein aggregation in alpha cells, which may contribute to impaired glucagon secretion via cytoskeletal dysfunction. We showed further that IDE deficiency triggers impairments in cilia formation, inducing alpha cell hyperplasia and possibly also contributing to dysregulated glucagon secretion and hyperglucagonaemia. CONCLUSIONS/INTERPRETATION We propose that loss of IDE function in alpha cells contributes to hyperglucagonaemia in type 2 diabetes.
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Affiliation(s)
- Beatriz Merino
- Unidad de Excelencia Instituto de Biología y Genética Molecular (University of Valladolid-CSIC), Valladolid, Spain
| | - Elena Casanueva-Álvarez
- Unidad de Excelencia Instituto de Biología y Genética Molecular (University of Valladolid-CSIC), Valladolid, Spain
| | - Iván Quesada
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández de Elche, Elche, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Carlos M González-Casimiro
- Unidad de Excelencia Instituto de Biología y Genética Molecular (University of Valladolid-CSIC), Valladolid, Spain
| | | | - Tamara Postigo-Casado
- Unidad de Excelencia Instituto de Biología y Genética Molecular (University of Valladolid-CSIC), Valladolid, Spain
| | - Malcolm A Leissring
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine (UCI MIND), Irvine, CA, USA
| | - Klaus H Kaestner
- Department of Genetics and Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania, Philadelphia, PA, USA
| | - Germán Perdomo
- Unidad de Excelencia Instituto de Biología y Genética Molecular (University of Valladolid-CSIC), Valladolid, Spain
| | - Irene Cózar-Castellano
- Unidad de Excelencia Instituto de Biología y Genética Molecular (University of Valladolid-CSIC), Valladolid, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain.
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de Sousa Melo SR, Dos Santos LR, da Cunha Soares T, Cardoso BEP, da Silva Dias TM, Morais JBS, de Paiva Sousa M, de Sousa TGV, da Silva NC, da Silva LD, Cruz KJC, do Nascimento Marreiro D. Participation of Magnesium in the Secretion and Signaling Pathways of Insulin: an Updated Review. Biol Trace Elem Res 2022; 200:3545-3553. [PMID: 35666386 DOI: 10.1007/s12011-021-02966-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 10/11/2021] [Indexed: 11/02/2022]
Abstract
Several studies have demonstrated the participation of various minerals in mechanisms involving insulin. Magnesium, in particular, plays an important role in the secretion and action of this hormone. Therefore, this review aimed to examine the latest insights into the biochemical and molecular aspects of the participation of magnesium in insulin sensitivity. Magnesium plays a vital role in the activity of intracellular proteins involved in insulin secretion in β-pancreatic cells, such as glucokinase, ATPase, and protein kinase C. In addition, evidence suggests that this mineral participates directly in insulin sensitivity and signaling in peripheral tissues, acting in the phosphorylation of the receptor tyrosine kinase and the insulin receptor substrates 1, insulin receptor substrates 2, phosphatidylinositol 3-kinase, and protein kinase B, and indirectly by reducing oxidative stress and chronic low-grade inflammation, which also lead to insulin resistance. Thus, magnesium deficiency is associated with glucose intolerance, while magnesium supplementation stimulates insulin secretion in pancreatic cells and improves insulin sensitivity in peripheral tissues. However, studies must consider assess short- and long-term nutritional status of mineral before performing intervention, the relevance of the balance of other nutrients that influence hormone secretion and sensibility, and health status of the assessed population.
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Affiliation(s)
| | - Loanne Rocha Dos Santos
- Graduate Program in Food and Nutrition, Federal University of Piauí, Teresina (Piauí), Brasil
| | - Tamires da Cunha Soares
- Graduate Program in Food and Nutrition, Federal University of Piauí, Teresina (Piauí), Brasil
| | | | | | | | - Mickael de Paiva Sousa
- Graduate Program in Food and Nutrition, Federal University of Piauí, Teresina (Piauí), Brasil
| | | | | | | | - Kyria Jayanne Clímaco Cruz
- Department of Nutrition, Health Sciences Center, Federal University of Piauí, Rua Hugo Napoleão, 665, Ed. Palazzo Reale, Apto 2001, Jockey, CEP 64048-320, Teresina, Piauí, Brasil
| | - Dilina do Nascimento Marreiro
- Department of Nutrition, Health Sciences Center, Federal University of Piauí, Rua Hugo Napoleão, 665, Ed. Palazzo Reale, Apto 2001, Jockey, CEP 64048-320, Teresina, Piauí, Brasil.
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Ofori JK, Karagiannopoulos A, Barghouth M, Nagao M, Andersson ME, Salunkhe VA, Zhang E, Wendt A, Eliasson L. The highly expressed calcium-insensitive synaptotagmin-11 and synaptotagmin-13 modulate insulin secretion. Acta Physiol (Oxf) 2022; 236:e13857. [PMID: 35753051 PMCID: PMC9541707 DOI: 10.1111/apha.13857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 12/01/2022]
Abstract
AIM SYT11 and SYT13, two calcium-insensitive synaptotagmins, are downregulated in islets from type-2 diabetic donors, but their function in insulin secretion is unknown. To address this, we investigated the physiological role of these two synaptotagmins in insulin secreting cells. METHODS Correlations between gene expression levels were performed using previously described RNA-seq data on islets from 188 human donors. SiRNA knockdown was performed in EndoC-βH1 and INS-1 832/13 cells. Insulin secretion was measured with ELISA. Patch clamp was used for single cell electrophysiology. Confocal microscopy was used to determine intra-cellular localization. RESULTS Human islet expression of the transcription factor PDX-1 was positively correlated with SYT11 (p = 2.4e-10 ) and SYT13 (p<2.2 e-16 ). Syt11 and Syt13 both co-localized with insulin, indicating their localization in insulin granules. Downregulation of Syt11 in INS-1 832/13 cells (siSYT11) resulted in increased basal and glucose-induced insulin secretion. Downregulation of Syt13 (siSYT13) decreased insulin secretion induced by glucose and K+ .Interestingly, the cAMP raising agent forskolin was unable to enhance insulin secretion in siSYT13 cells. There was no difference in insulin content, exocytosis, or voltage-gated Ca2+ currents in the two models. Double knockdown of Syt11 and Syt13 (DKD) resembled the results in siSYT13 cells. CONCLUSION SYT11 and SYT13 have similar localization and transcriptional regulation but they regulate insulin secretion differentially. While downregulation of SYT11 might be a compensatory mechanism in type-2 diabetes, downregulation of SYT13 reduces the insulin secretory response and overrules the compensatory regulation of SYT11 in a way that could aggravate the disease.
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Affiliation(s)
- Jones K Ofori
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis, Lund University Diabetes Centre, Lund University, Malmö, Sweden
| | - Alexandros Karagiannopoulos
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis, Lund University Diabetes Centre, Lund University, Malmö, Sweden
| | - Mohammad Barghouth
- Islet Pathophysiology, Department of Clinical Sciences Malmö, Lund University, Diabetes Centre, Lund University, Malmö, Sweden
| | - Mototsugu Nagao
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis, Lund University Diabetes Centre, Lund University, Malmö, Sweden.,Department of Endocrinology, Diabetes and Metabolism, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Markus E Andersson
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis, Lund University Diabetes Centre, Lund University, Malmö, Sweden
| | - Vishal A Salunkhe
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis, Lund University Diabetes Centre, Lund University, Malmö, Sweden.,Institute of Neuroscience and Physiology, Department of Physiology, Metabolism research unit, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Enming Zhang
- Islet Pathophysiology, Department of Clinical Sciences Malmö, Lund University, Diabetes Centre, Lund University, Malmö, Sweden
| | - Anna Wendt
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis, Lund University Diabetes Centre, Lund University, Malmö, Sweden
| | - Lena Eliasson
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis, Lund University Diabetes Centre, Lund University, Malmö, Sweden
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Chen L, Wang L, Ao W, Chen Y, Li S, Huang Z, Yu D, Dong Y, Gu J, Zeng H. Bioinformatics study of the potential therapeutic effects of ginsenoside Rf in reversing nonalcoholic fatty liver disease. Biomed Pharmacother 2022; 149:112879. [PMID: 35358801 DOI: 10.1016/j.biopha.2022.112879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/12/2022] [Accepted: 03/23/2022] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVE Ginsenoside Rf, a tetracyclic triterpenoid only present in Panax ginseng, has been proven to relieve lipid metabolism and inflammatory reactions, which can be a potential treatment for nonalcoholic fatty liver disease (NAFLD). Therefore, this study aimed to reveal the underlying mechanisms of ginsenoside Rf in the treatment of early-stage NAFLD (NAFL) by using a bioinformatics method and biological experiments. METHODS Target genes associated with NAFL were screened from the Gene Expression Omnibus (GEO) database, a database repository of high-throughput gene expression data and hybridization arrays, chips, and microarrays. Subsequently, gene set enrichment analysis was performed by using Gene Ontology enrichment analysis tool. Then, the binding capacity between ginsenoside Rf and NAFL-related targets was evaluated by molecular docking. Finally, the FFA-induced HepG2 cell model treated with ginsenoside Rf was adopted to verify the effect of ginsenoside Rf and the related mechanisms. RESULTS There were 41 common differentially expressed genes in the GEO dataset. Gene Ontology and Reactome pathway enrichment analysis of the differentially expressed genes showed that many pathways could be related to the pathogenesis of NAFL, including those participating in the cytokine-mediated signaling pathway, G protein-coupled receptor signaling pathway, and response to lipopolysaccharide. Finally, the qRT-PCR analysis results indicated that ginsenoside Rf therapy could ameliorate the transcription of ANXA2, BAZ1A, DNMT3L and MMP9. CONCLUSION Our research discovered the relevant mechanisms and basic pharmacological effects of ginsenoside Rf in the treatment of NAFL. These results might facilitate the development of ginsenoside Rf as an alternative medication for NAFL.
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Zmazek J, Grubelnik V, Markovič R, Marhl M. Modeling the Amino Acid Effect on Glucagon Secretion from Pancreatic Alpha Cells. Metabolites 2022; 12:metabo12040348. [PMID: 35448534 PMCID: PMC9028923 DOI: 10.3390/metabo12040348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 11/29/2022] Open
Abstract
Type 2 Diabetes Mellitus (T2DM) is a burdensome problem in modern society, and intensive research is focused on better understanding the underlying cellular mechanisms of hormone secretion for blood glucose regulation. T2DM is a bi-hormonal disease, and in addition to 100 years of increasing knowledge about the importance of insulin, the second hormone glucagon, secreted by pancreatic alpha cells, is becoming increasingly important. We have developed a mathematical model for glucagon secretion that incorporates all major metabolic processes of glucose, fatty acids, and glutamine as the most abundant postprandial amino acid in blood. In addition, we consider cAMP signaling in alpha cells. The model predictions quantitatively estimate the relative importance of specific metabolic and signaling pathways and particularly emphasize the important role of glutamine in promoting glucagon secretion, which is in good agreement with known experimental data.
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Affiliation(s)
- Jan Zmazek
- Faculty of Natural Sciences and Mathematics, University of Maribor, 2000 Maribor, Slovenia; (J.Z.); (R.M.)
| | - Vladimir Grubelnik
- Faculty of Electrical Engineering and Computer Science, University of Maribor, 2000 Maribor, Slovenia;
| | - Rene Markovič
- Faculty of Natural Sciences and Mathematics, University of Maribor, 2000 Maribor, Slovenia; (J.Z.); (R.M.)
- Faculty of Electrical Engineering and Computer Science, University of Maribor, 2000 Maribor, Slovenia;
| | - Marko Marhl
- Faculty of Natural Sciences and Mathematics, University of Maribor, 2000 Maribor, Slovenia; (J.Z.); (R.M.)
- Faculty of Education, University of Maribor, 2000 Maribor, Slovenia
- Faculty of Medicine, University of Maribor, 2000 Maribor, Slovenia
- Correspondence:
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Mi Z, Song Y, Wang J, Liu Z, Cao X, Dang L, Lu Y, Sun Y, Xiong H, Zhang L, Chen Y. cAMP-Induced Nuclear Condensation of CRTC2 Promotes Transcription Elongation and Cystogenesis in Autosomal Dominant Polycystic Kidney Disease. Adv Sci (Weinh) 2022; 9:e2104578. [PMID: 35037420 PMCID: PMC8981427 DOI: 10.1002/advs.202104578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Formation of biomolecular condensates by phase separation has recently emerged as a new principle for regulating gene expression in response to extracellular signaling. However, the molecular mechanisms underlying the coupling of signal transduction and gene activation through condensate formation, and how dysregulation of these mechanisms contributes to disease progression, remain elusive. Here, the authors report that CREB-regulated transcription coactivator 2 (CRTC2) translocates to the nucleus and forms phase-separated condensates upon activation of cAMP signaling. They show that intranuclear CRTC2 interacts with positive transcription elongation factor b (P-TEFb) and activates P-TEFb by disrupting the inhibitory 7SK snRNP complex. Aberrantly elevated cAMP signaling plays central roles in the development of autosomal dominant polycystic kidney disease (ADPKD). They find that CRTC2 localizes to the nucleus and forms condensates in cystic epithelial cells of both mouse and human ADPKD kidneys. Genetic depletion of CRTC2 suppresses cyst growth in an orthologous ADPKD mouse model. Using integrative transcriptomic and cistromic analyses, they identify CRTC2-regulated cystogenesis-associated genes, whose activation depends on CRTC2 condensate-facilitated P-TEFb recruitment and the release of paused RNA polymerase II. Together, their findings elucidate a mechanism by which CRTC2 nuclear condensation conveys cAMP signaling to transcription elongation activation and thereby promotes cystogenesis in ADPKD.
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Affiliation(s)
- Zeyun Mi
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Yandong Song
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Jiuchen Wang
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Zhiheng Liu
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Xinyi Cao
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Lin Dang
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Yumei Lu
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Yongzhan Sun
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Hui Xiong
- Department of UrologyShandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinanShandong250001China
| | - Lirong Zhang
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Yupeng Chen
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
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Khan D, Moffett RC, Flatt PR, Tarasov AI. Classical and non-classical islet peptides in the control of β-cell function. Peptides 2022; 150:170715. [PMID: 34958851 DOI: 10.1016/j.peptides.2021.170715] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/25/2021] [Accepted: 12/17/2021] [Indexed: 12/25/2022]
Abstract
The dual role of the pancreas as both an endocrine and exocrine gland is vital for food digestion and control of nutrient metabolism. The exocrine pancreas secretes enzymes into the small intestine aiding digestion of sugars and fats, whereas the endocrine pancreas secretes a cocktail of hormones into the blood, which is responsible for blood glucose control and regulation of carbohydrate, protein and fat metabolism. Classical islet hormones, insulin, glucagon, pancreatic polypeptide and somatostatin, interact in an autocrine and paracrine manner, to fine-tube the islet function and insulin secretion to the needs of the body. Recently pancreatic islets have been reported to express a number of non-classical peptide hormones involved in metabolic signalling, whose major production site was believed to reside outside pancreas, e.g. in the small intestine. We highlight the key non-classical islet peptides, and consider their involvement, together with established islet hormones, in regulation of stimulus-secretion coupling as well as proliferation, survival and transdifferentiation of β-cells. We furthermore focus on the paracrine interaction between classical and non-classical islet hormones in the maintenance of β-cell function. Understanding the functional relationships between these islet peptides might help to develop novel, more efficient treatments for diabetes and related metabolic disorders.
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Affiliation(s)
- Dawood Khan
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK.
| | - R Charlotte Moffett
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| | - Peter R Flatt
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| | - Andrei I Tarasov
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
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Nagao M, Lagerstedt JO, Eliasson L. Secretory granule exocytosis and its amplification by cAMP in pancreatic β-cells. Diabetol Int. [PMID: 35694000 PMCID: PMC9174382 DOI: 10.1007/s13340-022-00580-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/17/2022] [Indexed: 10/18/2022]
Abstract
The sequence of events for secreting insulin in response to glucose in pancreatic β-cells is termed "stimulus-secretion coupling". The core of stimulus-secretion coupling is a process which generates electrical activity in response to glucose uptake and causes Ca2+ oscillation for triggering exocytosis of insulin-containing secretory granules. Prior to exocytosis, the secretory granules are mobilized and docked to the plasma membrane and primed for fusion with the plasma membrane. Together with the final fusion with the plasma membrane, these steps are named the exocytosis process of insulin secretion. The steps involved in the exocytosis process are crucial for insulin release from β-cells and considered indispensable for glucose homeostasis. We recently confirmed a signature of defective exocytosis process in human islets and β-cells of obese donors with type 2 diabetes (T2D). Furthermore, cyclic AMP (cAMP) potentiates glucose-stimulated insulin secretion through mechanisms including accelerating the exocytosis process. In this mini-review, we aimed to organize essential knowledge of the secretory granule exocytosis and its amplification by cAMP. Then, we suggest the fatty acid translocase CD36 as a predisposition in β-cells for causing defective exocytosis, which is considered a pathogenesis of T2D in relation to obesity. Finally, we propose potential therapeutics of the defective exocytosis based on a CD36-neutralizing antibody and on Apolipoprotein A-I (ApoA-I), for improving β-cell function in T2D.
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Singh B, Khattab F, Gilon P. Glucose inhibits glucagon secretion by decreasing [Ca2+]c and by reducing the efficacy of Ca2+ on exocytosis via somatostatin-dependent and independent mechanisms. Mol Metab 2022; 61:101495. [PMID: 35421610 PMCID: PMC9065434 DOI: 10.1016/j.molmet.2022.101495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 03/15/2022] [Accepted: 04/04/2022] [Indexed: 11/15/2022] Open
Abstract
Objective Methods Results Conclusions Glucose modulates [Ca2+]c in α-cells within islets but not in dispersed α-cells. In α-cells within islets, it decreases [Ca2+]c independently of their KATP channels. It decreases α-cell [Ca2+]c partly via somatostatin. All glucose-induced [Ca2+]c changes trigger parallel changes in glucagon release. Glucose also decreases the efficacy of Ca2+ on exocytosis (attenuating pathway).
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Affiliation(s)
- Bilal Singh
- Université Catholique de Louvain, Institut de Recherche Expérimentale et Clinique, Pôle d'Endocrinologie, Diabète et Nutrition, Brussels, Belgium
| | - Firas Khattab
- Université Catholique de Louvain, Institut de Recherche Expérimentale et Clinique, Pôle d'Endocrinologie, Diabète et Nutrition, Brussels, Belgium
| | - Patrick Gilon
- Université Catholique de Louvain, Institut de Recherche Expérimentale et Clinique, Pôle d'Endocrinologie, Diabète et Nutrition, Brussels, Belgium.
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Kaneto H, Kimura T, Shimoda M, Obata A, Sanada J, Fushimi Y, Matsuoka T, Kaku K. Molecular Mechanism of Pancreatic β-Cell Failure in Type 2 Diabetes Mellitus. Biomedicines 2022; 10:818. [PMID: 35453568 PMCID: PMC9030375 DOI: 10.3390/biomedicines10040818] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 03/27/2022] [Accepted: 03/29/2022] [Indexed: 02/08/2023] Open
Abstract
Various important transcription factors in the pancreas are involved in the process of pancreas development, the differentiation of endocrine progenitor cells into mature insulin-producing pancreatic β-cells and the preservation of mature β-cell function. However, when β-cells are continuously exposed to a high glucose concentration for a long period of time, the expression levels of several insulin gene transcription factors are substantially suppressed, which finally leads to pancreatic β-cell failure found in type 2 diabetes mellitus. Here we show the possible underlying pathway for β-cell failure. It is likely that reduced expression levels of MafA and PDX-1 and/or incretin receptor in β-cells are closely associated with β-cell failure in type 2 diabetes mellitus. Additionally, since incretin receptor expression is reduced in the advanced stage of diabetes mellitus, incretin-based medicines show more favorable effects against β-cell failure, especially in the early stage of diabetes mellitus compared to the advanced stage. On the other hand, many subjects have recently suffered from life-threatening coronavirus infection, and coronavirus infection has brought about a new and persistent pandemic. Additionally, the spread of coronavirus infection has led to various limitations on the activities of daily life and has restricted economic development worldwide. It has been reported recently that SARS-CoV-2 directly infects β-cells through neuropilin-1, leading to apoptotic β-cell death and a reduction in insulin secretion. In this review article, we feature a possible molecular mechanism for pancreatic β-cell failure, which is often observed in type 2 diabetes mellitus. Finally, we are hopeful that coronavirus infection will decline and normal daily life will soon resume all over the world.
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Lei L, Huan Y, Liu Q, Li C, Cao H, Ji W, Gao X, Fu Y, Li P, Zhang R, Abliz Z, Liu Y, Liu S, Shen Z. Morus alba L. (Sangzhi) Alkaloids Promote Insulin Secretion, Restore Diabetic β-Cell Function by Preventing Dedifferentiation and Apoptosis. Front Pharmacol 2022; 13:841981. [PMID: 35308210 PMCID: PMC8927674 DOI: 10.3389/fphar.2022.841981] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/14/2022] [Indexed: 11/25/2022] Open
Abstract
Background:Morus alba L. (Sangzhi) alkaloids (SZ-A), extracted from the Chinese herb Morus alba L. (mulberry twig), have been shown to ameliorate hyperglycemia in type 2 diabetes and have been approved for diabetes treatment in the clinic. However, their versatile pharmacologic effects and regulatory mechanisms are not yet completely understood. Purpose: This study explored the protective effects of SZ-A on islet β cells and the underlying mechanism. Methods: Type 2 diabetic KKAy mice were orally administered SZ-A (100 or 200 mg/kg, once daily) for 11 weeks, and oral glucose tolerance, insulin tolerance, intraperitoneal glucose tolerance and hyperglycemia clamp tests were carried out to evaluate the potency of SZ-A in vivo. The morphology and β-cell dedifferentiation marker of KKAy mouse islets were detected via immunofluorescence. The effect of SZ-A on glucose-stimulated insulin secretion was investigated in both the islet β-cell line MIN6 and mouse primary islets. Potential regulatory signals and pathways in insulin secretion were explored, and cell proliferation assays and apoptosis TUNEL staining were performed on SZ-A-treated MIN6 cells. Results: SZ-A alleviated hyperglycemia and glucose intolerance in type 2 diabetic KKAy mice and improved the function and morphology of diabetic islets. In both MIN6 cells and primary islets, SZ-A promoted insulin secretion. At a normal glucose level, SZ-A decreased AMPKα phosphorylation, and at high glucose, SZ-A augmented the cytosolic calcium concentration. Additionally, SZ-A downregulated the β-cell dedifferentiation marker ALDH1A3 and upregulated β-cell identifying genes, such as Ins1, Ins2, Nkx2.2 and Pax4 in KKAy mice islets. At the same time, SZ-A attenuated glucolipotoxicity-induced apoptosis in MIN6 cells, and inhibited Erk1/2 phosphorylation and caspase 3 activity. The major active fractions of SZ-A, namely DNJ, FAG and DAB, participated in the above regulatory effects. Conclusion: Our findings suggest that SZ-A promotes insulin secretion in islet β cells and ameliorates β-cell dysfunction and mass reduction under diabetic conditions both in vivo and in vitro, providing additional supportive evidence for the clinical application of SZ-A.
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Affiliation(s)
- Lei Lei
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yi Huan
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- *Correspondence: Yi Huan, ; Shuainan Liu,
| | - Quan Liu
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Caina Li
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Hui Cao
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Wenming Ji
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xuefeng Gao
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yaxin Fu
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Pingping Li
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ruiping Zhang
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- CAMS Key Laboratory of Molecular Mechanism and Target Discovery of Metabolic Disorder and Tumorigenesis, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zeper Abliz
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- CAMS Key Laboratory of Molecular Mechanism and Target Discovery of Metabolic Disorder and Tumorigenesis, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yuling Liu
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Drug Delivery Technology and Novel Formulation, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shuainan Liu
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- *Correspondence: Yi Huan, ; Shuainan Liu,
| | - Zhufang Shen
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Key Laboratory of Polymorphic Drugs of Beijing, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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Hudson AD, Kauffman AS. Metabolic actions of kisspeptin signaling: Effects on body weight, energy expenditure, and feeding. Pharmacol Ther 2022; 231:107974. [PMID: 34530008 PMCID: PMC8884343 DOI: 10.1016/j.pharmthera.2021.107974] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/20/2021] [Accepted: 07/26/2021] [Indexed: 12/18/2022]
Abstract
Kisspeptin (encoded by the Kiss1 gene) and its receptor, KISS1R (encoded by the Kiss1r gene), have well-established roles in stimulating reproduction via central actions on reproductive neural circuits, but recent evidence suggests that kisspeptin signaling also influences metabolism and energy balance. Indeed, both Kiss1 and Kiss1r are expressed in many metabolically-relevant peripheral tissues, including both white and brown adipose tissue, the liver, and the pancreas, suggesting possible actions on these tissues or involvement in their physiology. In addition, there may be central actions of kisspeptin signaling, or factors co-released from kisspeptin neurons, that modulate metabolic, feeding, or thermoregulatory processes. Accumulating data from animal models suggests that kisspeptin signaling regulates a wide variety of metabolic parameters, including body weight and energy expenditure, adiposity and adipose tissue function, food intake, glucose metabolism, respiratory rates, locomotor activity, and thermoregulation. Herein, the current evidence for the involvement of kisspeptin signaling in each of these physiological parameters is reviewed, gaps in knowledge identified, and future avenues of important research highlighted. Collectively, the discussed findings highlight emerging non-reproductive actions of kisspeptin signaling in metabolism and energy balance, in addition to previously documented roles in reproductive control, but also emphasize the need for more research to resolve current controversies and uncover underlying molecular and physiological mechanisms.
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Affiliation(s)
- Alexandra D Hudson
- Dept. of OBGYN and Reproductive Sciences, University of California San Diego, La Jolla, CA 92093, United States of America
| | - Alexander S Kauffman
- Dept. of OBGYN and Reproductive Sciences, University of California San Diego, La Jolla, CA 92093, United States of America.
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48
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Wierup N, Abels M, Shcherbina L, Lindqvist A. The role of CART in islet biology. Peptides 2022; 149:170708. [PMID: 34896575 DOI: 10.1016/j.peptides.2021.170708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/03/2021] [Accepted: 12/03/2021] [Indexed: 10/19/2022]
Abstract
Cocaine- and amphetamine-regulated transcript (CART) is mostly known for its appetite regulating effects in the central nervous system. However, CART is also highly expressed in the peripheral nervous system as well as in certain endocrine cells. Our group has dedicated more than 20 years to understand the role of CART in the pancreatic islets and in this review we summarize what is known to date about CART expression and function in the islets. CART is expressed in both islet cells and nerve fibers innervating the islets. Large species differences are at hand and CART expression is highly dynamic and increased during development, as well as in Type 2 Diabetes and certain endocrine tumors. In the human islets CART is expressed in alpha cells and beta cells and the expression is increased in T2D patients. CART increases insulin secretion, reduces glucagon secretion, and protects against beta cell death by reducing apoptosis and increasing proliferation. It is still not fully understood how CART mediates its effects or which receptors that are involved. Nevertheless, CART is endowed with several properties that are beneficial in a T2D perspective. Many of the described effects of CART resemble those of GLP-1, and interestingly CART has been found to potentiate some of the effects of GLP-1, paving the way for CART-based treatments in combination with GLP-1-based drugs.
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Affiliation(s)
- Nils Wierup
- Lund University Diabetes Centre, Malmö, Sweden.
| | - Mia Abels
- Lund University Diabetes Centre, Malmö, Sweden
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49
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Abstract
Glucose homeostasis is maintained by the glucoregulatory hormones, glucagon, insulin and somatostatin, secreted from the islets of Langerhans. Glucagon is the body's most important anti-hypoglycemic hormone, mobilizing glucose from glycogen stores in the liver in response to fasting, thus maintaining plasma glucose levels within healthy limits. Glucagon secretion is regulated by both circulating nutrients, hormones and neuronal inputs. Hormones that may regulate glucagon secretion include locally produced insulin and somatostatin, but also urocortin-3, amylin and pancreatic polypeptide, and from outside the pancreas glucagon-like peptide-1 and 2, peptide tyrosine tyrosine and oxyntomodulin, glucose-dependent insulinotropic polypeptide, neurotensin and ghrelin, as well as the hypothalamic hormones arginine-vasopressin and oxytocin, and calcitonin from the thyroid. Each of these hormones have distinct effects, ranging from regulating blood glucose, to regulating appetite, stomach emptying rate and intestinal motility, which makes them interesting targets for treating metabolic diseases. Awareness regarding the potential effects of the hormones on glucagon secretion is important since secretory abnormalities could manifest as hyperglycemia or even lethal hypoglycemia. Here, we review the effects of each individual hormone on glucagon secretion, their interplay, and how treatments aimed at modulating the plasma levels of these hormones may also influence glucagon secretion and glycemic control.
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Affiliation(s)
- Daniel B Andersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen N, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen N, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
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50
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Khodadadi M, Jafari-Gharabaghlou D, Zarghami N. An update on mode of action of metformin in modulation of meta-inflammation and inflammaging. Pharmacol Rep 2022; 74:310-322. [PMID: 35067907 DOI: 10.1007/s43440-021-00334-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/11/2021] [Accepted: 10/13/2021] [Indexed: 12/13/2022]
Abstract
Type 2 diabetes mellitus (T2DM) is the most common chronic metabolic condition. Several genetic and environmental factors are involved in developing T2DM. Aging, inflammation, and obesity are the main contributors to the initiation of T2DM. They cause chronic sterile meta-inflammation and insulin resistance, thereby making a person more susceptible to developing T2DM. Metformin, a natural cationic biguanide, is widely used as the first-line treatment of T2DM. The exact action mechanism behind the glucose-lowering effect of metformin is not clear, but, presumably, metformin utilizes a broad spectrum of molecular mechanisms to control blood glucose including decreasing intestinal glucose absorption, inhibition of the hepatic gluconeogenesis, decreasing insulin resistance, etc. Recent studies have shown that metformin exerts its effects through the inhibition of mitochondrial respiratory chain complex 1 and the AMP-activated protein kinase (AMPK) activation, but it has been identified in the other studies that AMPK is not the sole hub in metformin mode of action or there are other unknown mechanisms which are involved and yet to be explored. Therefore, here, we discuss the updated findings of the mechanism of action of metformin that contributes to the meta-inflammation and inflammaging action. It is proposed that figuring out the precise mechanism of action of metformin could improve its application in the fields of obesity, inflammation, aging, and inflammaging.
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Affiliation(s)
- Meysam Khodadadi
- Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Davoud Jafari-Gharabaghlou
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Clinical Biochemistry and Laboratory Medicine, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Nosratollah Zarghami
- Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran. .,Department of Medical Biochemistry, Faculty of Medicine, Istanbul Aydin University, Istanbul, Turkey. .,Department of Clinical Biochemistry and Laboratory Medicine, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
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