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Zhang X, Bao J, Zhang Y, Wang X. Alpha-Linolenic Acid Ameliorates Cognitive Impairment and Liver Damage Caused by Obesity. Diabetes Metab Syndr Obes 2024; 17:981-995. [PMID: 38435630 PMCID: PMC10909331 DOI: 10.2147/dmso.s434671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 12/13/2023] [Indexed: 03/05/2024] Open
Abstract
Background Obesity is a growing global problem that causes various complications such as diabetes, cognitive dysfunction, cardiovascular diseases, and hepatobiliary disease. Alpha-linolenic acid (ALA) has been reported to exhibit multiple pharmaceutical effects. This study aimed to explore the effects of ALA on obesity-induced adipose tissue accumulation, cognitive impairment, inflammation, and colonic mucosal barrier integrity. Methods Mice were fed with high-fat diet (HFD) and were treated with ALA (60 or 100 mg/kg). Body weight, adipose tissue, serum glucose and lipid levels, glucose resistance, and insulin resistance were measured. Cognitive ability was analyzed using the behavior tests. PTP1B and IRS/p-AKT/p-GSK3β/p-Tau signaling were examined to evaluate inflammation and synaptogenesis. Colon mucosal barrier integrity was examined by Alcian blue staining and expression of the tight junction proteins. The production of pro-inflammatory cytokines and liver damages were evaluated. 3T3-L1 cells were used for in vitro experiments. Cell viability, migration and invasion were detected. The levels of ROS, iron, and ferrous ions were measured to assess ferroptosis. Metabolomic analysis of adipose tissues was performed. Results ALA treatment prevented HFD-induced adipose tissue accumulation, improved glucose and lipid homeostasis and metabolism. Administration of ALA repressed the HFD-induced increase in insulin levels and insulin resistance index. Serum and colon levels of pro-inflammatory cytokines were decreased after ALA treatment. ALA elevated mitochondrial content in brown adipose tissues. ALA ameliorated obesity-induced cognitive impairment and hippocampal inflammation, enhanced colon mucosa integrity. ALA treatment ameliorated HFD-induced liver damage and lipid accumulation and inhibited differentiation of preadipocyte 3T3-L1 cells into mature adipocytes and induces ferroptosis. Metabolomic analysis suggested that ALA may target the glycerolipid metabolism pathway to ameliorate obesity. Knockdown of AGPAT2 abolished the protective effects of ALA. Conclusion ALA treatment suppressed adipose accumulation in adipocytes, improved cognitive ability and colon integrity, and alleviated liver damage by modulating the 1-acylglycerol-3-phosphate O-acyltransferase 2 (AGPAT2).
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Affiliation(s)
- Xian Zhang
- College of Traditional Chinese Veterinary Medicine, Hebei Agricultural University, Baoding, 071001, People’s Republic of China
| | - Jialu Bao
- College of Traditional Chinese Veterinary Medicine, Hebei Agricultural University, Baoding, 071001, People’s Republic of China
| | - Yan Zhang
- College of Traditional Chinese Veterinary Medicine, Hebei Agricultural University, Baoding, 071001, People’s Republic of China
| | - Xiaodan Wang
- College of Traditional Chinese Veterinary Medicine, Hebei Agricultural University, Baoding, 071001, People’s Republic of China
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Zhihong Y, Chen W, Qianqian Z, Lidan S, Qiang Z, Jing H, Wenxi W, Bhawal R. Emerging roles of oxyntomodulin-based glucagon-like peptide-1/glucagon co-agonist analogs in diabetes and obesity. Peptides 2023; 162:170955. [PMID: 36669563 DOI: 10.1016/j.peptides.2023.170955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 01/13/2023] [Accepted: 01/13/2023] [Indexed: 01/19/2023]
Abstract
Oxyntomodulin (OXM) is an endogenous peptide hormone secreted from the intestines following nutrient ingestion that activates both glucagon-like peptide-1 (GLP-1) and glucagon receptors. OXM is known to exert various effects, including improvement in glucose tolerance, promotion of energy expenditure, acceleration of liver lipolysis, inhibition of food intake, delay of gastric emptying, neuroprotection, and pain relief. The antidiabetic and antiobesity properties have led to the development of biologically active and enzymatically stable OXM-based analogs with proposed therapeutic promise for metabolic diseases. Structural modification of OXM was ongoing to enhance its potency and prolong half-life, and several GLP-1/glucagon dual receptor agonist-based therapies are being explored in clinical trials for the treatment of type 2 diabetes mellitus and its complications. In the present article, we provide a brief overview of the physiology of OXM, focusing on its structural-activity relationship and ongoing clinical development.
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Affiliation(s)
- Yao Zhihong
- Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, College of Medicine, Jiaxing University, Jiaxing 314001, China; College of Pharmacy, Zhejiang University of Technology, Hangzhou 310000, China
| | - Wang Chen
- Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, College of Medicine, Jiaxing University, Jiaxing 314001, China
| | - Zhu Qianqian
- Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, College of Medicine, Jiaxing University, Jiaxing 314001, China
| | - Sun Lidan
- Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, College of Medicine, Jiaxing University, Jiaxing 314001, China.
| | - Zhou Qiang
- The First Hospital of Jiaxing & The Affiliated Hospital of Jiaxing University, Jiaxing 314001, China.
| | - Han Jing
- School of Chemistry & Materials Science, Jiangsu Normal University, Xuzhou 221116, China
| | - Wang Wenxi
- The First Hospital of Jiaxing & The Affiliated Hospital of Jiaxing University, Jiaxing 314001, China; College of Pharmacy, Zhejiang University of Technology, Hangzhou 310000, China
| | - Ruchika Bhawal
- Proteomics and Metabolomics Facility, Institute of Biotechnology, Cornell University, Ithaca, NY, USA
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Fadó R, Molins A, Rojas R, Casals N. Feeding the Brain: Effect of Nutrients on Cognition, Synaptic Function, and AMPA Receptors. Nutrients 2022; 14:nu14194137. [PMID: 36235789 PMCID: PMC9572450 DOI: 10.3390/nu14194137] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 11/05/2022] Open
Abstract
In recent decades, traditional eating habits have been replaced by a more globalized diet, rich in saturated fatty acids and simple sugars. Extensive evidence shows that these dietary factors contribute to cognitive health impairment as well as increase the incidence of metabolic diseases such as obesity and diabetes. However, how these nutrients modulate synaptic function and neuroplasticity is poorly understood. We review the Western, ketogenic, and paleolithic diets for their effects on cognition and correlations with synaptic changes, focusing mainly (but not exclusively) on animal model studies aimed at tracing molecular alterations that may contribute to impaired human cognition. We observe that memory and learning deficits mediated by high-fat/high-sugar diets, even over short exposure times, are associated with reduced arborization, widened synaptic cleft, narrowed post-synaptic zone, and decreased activity-dependent synaptic plasticity in the hippocampus, and also observe that these alterations correlate with deregulation of the AMPA-type glutamate ionotropic receptors (AMPARs) that are crucial to neuroplasticity. Furthermore, we explored which diet-mediated mechanisms modulate synaptic AMPARs and whether certain supplements or nutritional interventions could reverse deleterious effects, contributing to improved learning and memory in older people and patients with Alzheimer’s disease.
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Affiliation(s)
- Rut Fadó
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, E-08195 Sant Cugat del Vallès, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, E-28029 Madrid, Spain
- Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Cerdanyola del Vallès, Spain
- Correspondence: ; Tel.: +34-93-504-20-00
| | - Anna Molins
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, E-08195 Sant Cugat del Vallès, Spain
| | - Rocío Rojas
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, E-08195 Sant Cugat del Vallès, Spain
| | - Núria Casals
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, E-08195 Sant Cugat del Vallès, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, E-28029 Madrid, Spain
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Kinna S, Ouberaï MM, Sonzini S, Gomes Dos Santos AL, Welland ME. Thermo-Responsive self-assembly of a dual glucagon-like peptide and glucagon receptor agonist. Int J Pharm 2021; 604:120719. [PMID: 34015379 DOI: 10.1016/j.ijpharm.2021.120719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 05/13/2021] [Accepted: 05/13/2021] [Indexed: 01/02/2023]
Abstract
The human peptide hormone Oxyntomodulin (Oxm) is known to induce satiety, increase energy expenditure, and control blood glucose in humans, making it a promising candidate for treatment of obesity and/or type 2 diabetes mellitus. However, a pharmaceutical exploitation has thus far been impeded by fast in vivo clearance and the molecule's sensitivity to half-life extending structural modifications. We recently showed that Oxm self-assembles into amyloid-like nanofibrils that continuously release active, soluble Oxm in a peptide-deprived environment. S.c. injected Oxm nanofibrils extended plasma exposure from a few hours to five days in rodents, compared to s.c. applied soluble Oxm. Here we show that Oxm fibril elongation kinetics and thermodynamics display a uniquely low temperature optimum compared to previously reported amyloid-like peptide and protein assemblies. Elongation rate is optimal at room temperature, with association rates 2-3 times higher at 25 °C than at ≥37 °C or ≤20 °C. We deduce from a combination of Cryo electron microscopy and spectroscopic methods that Oxm fibrils have a double-layered, triangular cross-section composed of arch-shaped monomers. We suggest a thermodynamic model that links the necessary molecular rearrangements during fibrillation and peptide release to the unique temperature effects in Oxm self-assembly and disassembly.
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Affiliation(s)
- Sonja Kinna
- Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge CB30FF, UK
| | - Myriam M Ouberaï
- Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge CB30FF, UK.
| | - Silvia Sonzini
- Pharmaceutical Sciences, R&D BioPharmaceuticals, AstraZeneca, Granta Park, Cambridge CB21 6GH, UK
| | - Ana L Gomes Dos Santos
- Pharmaceutical Sciences, R&D BioPharmaceuticals, AstraZeneca, Granta Park, Cambridge CB21 6GH, UK.
| | - Mark E Welland
- Pharmaceutical Sciences, R&D BioPharmaceuticals, AstraZeneca, Granta Park, Cambridge CB21 6GH, UK
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Encapsulation Strategies for Pancreatic Islet Transplantation without Immune Suppression. CURRENT STEM CELL REPORTS 2021. [DOI: 10.1007/s40778-021-00190-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Shi H, Yu Y, Lin D, Zheng P, Zhang P, Hu M, Wang Q, Pan W, Yang X, Hu T, Li Q, Tang R, Zhou F, Zheng K, Huang XF. β-glucan attenuates cognitive impairment via the gut-brain axis in diet-induced obese mice. MICROBIOME 2020; 8:143. [PMID: 33008466 PMCID: PMC7532656 DOI: 10.1186/s40168-020-00920-y] [Citation(s) in RCA: 106] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 09/08/2020] [Indexed: 05/11/2023]
Abstract
BACKGROUND "Western" style dietary patterns are characterized by a high proportion of highly processed foods rich in fat and low in fiber. This diet pattern is associated with a myriad of metabolic dysfunctions, including neuroinflammation and cognitive impairment. β-glucan, the major soluble fiber in oat and barley grains, is fermented in the lower gastrointestinal tract, potentially impacting the microbial ecosystem and thus may improve elements of cognition and brain function via the gut-brain axis. The present study aimed to evaluate the effect of β-glucan on the microbiota gut-brain axis and cognitive function in an obese mouse model induced by a high-fat and fiber-deficient diet (HFFD). RESULTS After long-term supplementation for 15 weeks, β-glucan prevented HFFD-induced cognitive impairment assessed behaviorally by object location, novel object recognition, and nesting building tests. In the hippocampus, β-glucan countered the HFFD-induced microglia activation and its engulfment of synaptic puncta, and upregulation of proinflammatory cytokine (TNF-α, IL-1β, and IL-6) mRNA expression. Also, in the hippocampus, β-glucan significantly promoted PTP1B-IRS-pAKT-pGSK3β-pTau signaling for synaptogenesis, improved the synaptic ultrastructure examined by transmission electron microscopy, and increased both pre- and postsynaptic protein levels compared to the HFFD-treated group. In the colon, β-glucan reversed HFFD-induced gut barrier dysfunction increased the thickness of colonic mucus (Alcian blue and mucin-2 glycoprotein immunofluorescence staining), increased the levels of tight junction proteins occludin and zonula occludens-1, and attenuated bacterial endotoxin translocation. The HFFD resulted in microbiota alteration, effects abrogated by long-term β-glucan supplementation, with the β-glucan effects on Bacteroidetes and its lower taxa particularly striking. Importantly, the study of short-term β-glucan supplementation for 7 days demonstrated pronounced, rapid differentiating microbiota changes before the cognitive improvement, suggesting the possible causality of gut microbiota profile on cognition. In support, broad-spectrum antibiotic intervention abrogated β-glucan's effects on improving cognition, highlighting the role of gut microbiota to mediate cognitive behavior. CONCLUSION This study provides the first evidence that β-glucan improves indices of cognition and brain function with major beneficial effects all along the gut microbiota-brain axis. Our data suggest that elevating consumption of β-glucan-rich foods is an easily implementable nutritional strategy to alleviate detrimental features of gut-brain dysregulation and prevent neurodegenerative diseases associated with Westernized dietary patterns. Video Abstract.
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Affiliation(s)
- Hongli Shi
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Yinghua Yu
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China.
| | - Danhong Lin
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Peng Zheng
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, 2522, Australia
- School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Peng Zhang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Minmin Hu
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Qiao Wang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Wei Pan
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Xiaoying Yang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Tao Hu
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Qianqian Li
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Renxian Tang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Feng Zhou
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Kuiyang Zheng
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China.
| | - Xu-Feng Huang
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, 2522, Australia.
- School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia.
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Pei Z, Zhou D, Yan J, Wang S, Yang X, Pei Z. Design and characterization of novel oxyntomodulin derivatives with potent dual GLP-1/glucagon receptor activation and prolonged antidiabetic effects. Life Sci 2020; 253:117651. [PMID: 32304764 DOI: 10.1016/j.lfs.2020.117651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 04/05/2020] [Accepted: 04/06/2020] [Indexed: 11/18/2022]
Abstract
AIMS To investigate the combination of dimerization and PEGylation to enhance the receptor activation and in vivo stability of Oxyntomodulin (OXM). MAIN METHODS All LDM peptides were produced by using standard method of solid phase synthesis. The in vitro effects of LDM peptides were assessed by glucagon-like peptide-1 receptor (GLP-1R) and glucagon receptor (GcgR) binding test and Proteolytic stability test. Subsequently, saline, Liraglutide and three doses of LDM-3 treated groups were subjected to the evaluation of aute and long-term efficacy. KEY FINDINGS Five long-acting OXM conjugates, termed LDM-1 to LDM-5, were designed using cysteine (Cys)-specific modification reaction including the activated PEG, bisMal-NH2, and OXM-Cys, and all prepared with high purity. LDM-3 exhibited greater GLP-1R and GcgR activation and ameliorative serum stability. In addition, LDM-3 was identified with enhanced insulinotropic and glycemic abilities in the gene knockout mice. The prolonged glucose-lowering effects of the LDM-3 were proved by hypoglycemic duration test and multiple oral glucose tolerance tests (OGTTs) in the diet-induced obesity (DIO) mice. Furthermore, the pharmacokinetic tests in Sprague Dawley (SD) rat and cynomolgus monkey exhibited the lifespans of LDM-3 at 90 nmol·kg-1 were 101.5 h and 119.4 h, respectively. Nevertheless, consecutive 8-week administration of LDM-3 improved the cumulative body weight gain, food intake, % HbA1c, glucose tolerance and the pancreatic of the obese mice. SIGNIFICANCE LDM-3, as a dual GLP-1R and GcgR agonist, holds potential to be developed as a promising therapeutic candidate for both diabetes and obesity.
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Affiliation(s)
- Zengyang Pei
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China; Hangzhou RunChongGuiMei Bio-tech Co., Ltd., Xiao Shan, Hangzhou 310058, PR China.
| | - Degang Zhou
- National Research Center for Veterinary Medicine, Road Cuiwei, High-Tech District, Luoyang 471003, PR China
| | - Jie Yan
- Suzhou Xishan Zhongke Drug R&D Co., Ltd., Wuzhong Avenue, Suzhou 215000, PR China
| | - Shenghao Wang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China
| | - Xu Yang
- Hangzhou RunChongGuiMei Bio-tech Co., Ltd., Xiao Shan, Hangzhou 310058, PR China
| | - Zengju Pei
- Hangzhou RunChongGuiMei Bio-tech Co., Ltd., Xiao Shan, Hangzhou 310058, PR China
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Shi H, Wang Q, Zheng M, Hao S, Lum JS, Chen X, Huang XF, Yu Y, Zheng K. Supplement of microbiota-accessible carbohydrates prevents neuroinflammation and cognitive decline by improving the gut microbiota-brain axis in diet-induced obese mice. J Neuroinflammation 2020; 17:77. [PMID: 32127019 PMCID: PMC7055120 DOI: 10.1186/s12974-020-01760-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/26/2020] [Indexed: 12/18/2022] Open
Abstract
Background Western pattern diets induce neuroinflammation and impair cognitive behavior in humans and animals. Neuroinflammation and cognitive impairment have been associated with microbiota dysbiosis, through the gut-brain axis. Furthermore, microbiota-accessible carbohydrates (MACs) found in dietary fiber are important in shaping the microbial ecosystem and have the potential to improve the gut-brain-axis. However, the effects of MACs on neuroinflammation and cognition in an obese condition have not yet been investigated. The present study aimed to evaluate the effect of MACs on the microbiota-gut-brain axis and cognitive function in obese mice induced by a high-fat and fiber deficient (HF-FD) diet. Methods C57Bl/6 J male mice were fed with either a control HF-FD or a HF-MAC diet for 15 weeks. Moreover, an additional group was fed with the HF-MAC diet in combination with an antibiotic cocktail (HF-MAC + AB). Following the 15-week treatment, cognitive behavior was investigated; blood, cecum content, colon, and brain samples were collected to determine metabolic parameters, endotoxin, gut microbiota, colon, and brain pathology. Results We report MACs supplementation prevented HF-FD-induced cognitive impairment in nesting building and temporal order memory tests. MACs prevented gut microbiota dysbiosis, including increasing richness, α-diversity and composition shift, especially in Bacteroidetes and its lower taxa. Furthermore, MACs increased colonic mucus thickness, tight junction protein expression, reduced endotoxemia, and decreased colonic and systemic inflammation. In the hippocampus, MACs suppressed HF-FD-induced neuroglia activation and inflammation, improved insulin IRS-pAKT-pGSK3β-pTau synapse signaling, in addition to the synaptic ultrastructure and associated proteins. Furthermore, MACs’ effects on improving colon–cognitive parameters were eliminated by wide spectrum antibiotic microbiota ablation. Conclusions These results suggest that MACs improve cognitive impairments via the gut microbiota-brain axis induced by the consumption of an HF-FD. Supplemental MACs to combat obesity-related gut and brain dysfunction offer a promising approach to prevent neurodegenerative diseases associated with Westernized dietary patterns and obesity.
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Affiliation(s)
- Hongli Shi
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Qiao Wang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Mingxuan Zheng
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Shanshan Hao
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Jeremy S Lum
- Illawarra Health and Medical Research Institute (IHMRI), School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Xi Chen
- Illawarra Health and Medical Research Institute (IHMRI), School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Xu-Feng Huang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China.,Illawarra Health and Medical Research Institute (IHMRI), School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Yinghua Yu
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China.
| | - Kuiyang Zheng
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China.
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Wang L, Zhao J, Wang C, Hou X, Ning N, Sun C, Guo S, Yuan Y, Li L, Hölscher C, Wang X. D-Ser2-oxyntomodulin ameliorated Aβ31-35-induced circadian rhythm disorder in mice. CNS Neurosci Ther 2020; 26:343-354. [PMID: 31411808 PMCID: PMC7053239 DOI: 10.1111/cns.13211] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 07/25/2019] [Accepted: 07/30/2019] [Indexed: 01/21/2023] Open
Abstract
INTRODUCTION The occurrence of circadian rhythm disorder in patients with Alzheimer's disease (AD) is closely related to the abnormal deposition of amyloid-β (Aβ), and d-Ser2-oxyntomodulin (Oxy) is a protease-resistant oxyntomodulin analogue that has been shown to exert neuroprotective effects. AIMS This study aimed to explore whether Oxy, a new GLP-1R/GCGR dual receptor agonist, can improve the Aβ-induced disrupted circadian rhythm and the role of GLP-1R. METHODS A mouse wheel-running experiment was performed to explore the circadian rhythm, and western blotting and real-time PCR were performed to assess the expression of the circadian clock genes Bmal1 and Per2. Furthermore, a lentivirus encoding an shGLP-1R-GFP-PURO was used to interfere with GLP-1R gene expression and so explore the role of GLP-1R. RESULTS The present study has confirmed that Oxy could restore Aβ31-35-induced circadian rhythm disorders and improve the abnormal expression of Bmal1 and Per2. After interfering the GLP-1R gene, we found that Oxy could not improve the Aβ31-35-induced circadian rhythm disorder and abnormal expression of clock genes. CONCLUSION This study demonstrated that Oxy could improve Aβ31-35-induced circadian rhythm disorders, and GLP-1R plays a critical role. This study thus describes a novel target that may be potentially used in the treatment of AD.
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Affiliation(s)
- Li Wang
- Department of PathologyShanxi Medical UniversityTaiyuanChina
| | - Jin Zhao
- Department of PathologyShanxi Medical UniversityTaiyuanChina
| | - Chang‐Tu Wang
- Department of PathologyShanxi Medical UniversityTaiyuanChina
- Laboratory of ChronobiologyShanxi Medical UniversityTaiyuanChina
| | - Xiao‐Hong Hou
- Department of PathologyShanxi Medical UniversityTaiyuanChina
| | - Na Ning
- Department of PathologyShanxi Medical UniversityTaiyuanChina
| | - Cong Sun
- Department of PathologyShanxi Medical UniversityTaiyuanChina
| | - Shuai Guo
- Department of PathologyShanxi Medical UniversityTaiyuanChina
| | - Yuan Yuan
- Laboratory of Morphology, Department of Basic Medical SciencesShanxi Medical UniversityTaiyuanChina
| | - Lin Li
- Key Laboratory of Cellular PhysiologyShanxi Medical UniversityTaiyuanChina
| | - Christian Hölscher
- Second HospitalShanxi Medical UniversityTaiyuanChina
- Biomedical and Life Science, Faculty of Health and MedicineLancaster UniversityLancasterUK
| | - Xiao‐Hui Wang
- Department of PathologyShanxi Medical UniversityTaiyuanChina
- Laboratory of ChronobiologyShanxi Medical UniversityTaiyuanChina
- Laboratory of Morphology, Department of Basic Medical SciencesShanxi Medical UniversityTaiyuanChina
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Sarnobat D, Moffett RC, Gault VA, Tanday N, Reimann F, Gribble FM, Flatt PR, Irwin N. Effects of long-acting GIP, xenin and oxyntomodulin peptide analogues on alpha-cell transdifferentiation in insulin-deficient diabetic Glu CreERT2;ROSA26-eYFP mice. Peptides 2020; 125:170205. [PMID: 31738969 PMCID: PMC7212078 DOI: 10.1016/j.peptides.2019.170205] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/08/2019] [Accepted: 11/13/2019] [Indexed: 02/08/2023]
Abstract
Enzyme-resistant long-acting forms of the gut-derived peptide hormones, glucose-dependent insulinotropic polypeptide (GIP), xenin and oxyntomodulin (Oxm) have been generated, and exert beneficial effects on diabetes control and pancreatic islet architecture. The current study has employed alpha-cell lineage tracing in GluCreERT2;ROSA26-eYFP transgenic mice to investigate the extent to which these positive pancreatic effects are associated with alpha- to beta-cell transdifferentiation. Twice-daily administration of (D-Ala2)GIP, xenin-25[Lys13PAL] or (D-Ser2)-Oxm[Lys38PAL] for 10 days to streptozotocin (STZ)-induced diabetic mice did not affect body weight, food intake or blood glucose levels, but (D-Ser2)-Oxm[Lys38PAL] reduced (P < 0.05 to P < 0.001) fluid intake and circulating glucagon. (D-Ala2)GIP and (D-Ser2)-Oxm[Lys38PAL] also augmented (P < 0.05 and P < 0.01, respectively) pancreatic insulin content. Detrimental changes of pancreatic morphology induced by STZ in GluCreERT2;ROSA26-eYFP mice were partially reversed by all treatment interventions. This was associated with reduced (P < 0.05) apoptosis and increased (P < 0.05 to P < 0.01) proliferation of beta-cells, alongside opposing effects on alpha-cells, with (D-Ala2)GIP and (D-Ser2)-Oxm[Lys38PAL] being particularly effective in this regard. Alpha-cell lineage tracing revealed that induction of diabetes was accompanied by increased (P < 0.01) transdifferentiation of glucagon positive alpha-cells to insulin positive beta-cells. This islet cell transitioning process was augmented (P < 0.01 and P < 0.001, respectively) by (D-Ala2)GIP and (D-Ser2)-Oxm[Lys38PAL]. (D-Ser2)-Oxm[Lys38PAL] also significantly (P < 0.05) promoted loss of alpha-cell identity in favour of other endocrine islet cells. These data highlight intra-islet benefits of (D-Ala2)GIP, xenin-25[Lys13PAL] and (D-Ser2)-Oxm[Lys38PAL] in diabetes with beta-cell loss induced by STZ. The effects appear to be independent of glycaemic change, and associated with alpha- to beta-cell transdifferentiation for the GIP and Oxm analogues.
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Affiliation(s)
- Dipak Sarnobat
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - R Charlotte Moffett
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - Victor A Gault
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - Neil Tanday
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - Frank Reimann
- Wellcome Trust-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Fiona M Gribble
- Wellcome Trust-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Peter R Flatt
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - Nigel Irwin
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK.
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11
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Wang ZJ, Han YF, Zhao F, Yang GZ, Yuan L, Cai HY, Yang JT, Holscher C, Qi JS, Wu MN. A dual GLP-1 and Gcg receptor agonist rescues spatial memory and synaptic plasticity in APP/PS1 transgenic mice. Horm Behav 2020; 118:104640. [PMID: 31765661 DOI: 10.1016/j.yhbeh.2019.104640] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 11/16/2019] [Accepted: 11/16/2019] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease that severely affects the health and lifespan of the elderly worldwide. Recently, the correlation between AD and type 2 diabetes mellitus (T2DM) has received intensive attention, and a promising new anti-AD strategy is the use of anti-diabetic drugs. Oxyntomodulin (Oxm) is a peptide hormone and growth factor that acts on neurons in the hypothalamus. OXM activates glucagon-like peptide 1 (GLP-1) and glucagon (Gcg) receptors, facilitates insulin signaling and has neuroprotective effects against Aβ1-42-induced cytotoxicity in primary hippocampal neurons. Here, we tested the effects of the protease-resistant analogue (D-Ser2)Oxm on spatial memory and synaptic plasticity and the underlying molecular mechanisms in the APP/PS1 transgenic mouse model of AD. The results showed that (D-Ser2)Oxm not only alleviated the impairments of working memory and long-term spatial memory, but also reduced the number of Aβ plaques in the hippocampus, and reversed the suppression of hippocampal synaptic long-term potentiation (LTP). Moreover, (D-Ser2)Oxm administration significantly increased p-PI3K/p-AKT1 expression and decreased p-GSK3β levels in the hippocampus. These results are the first to show an in vivo neuroprotective role of (D-Ser2)Oxm in APP/PS1 mice, and this role involves the improvement of synaptic plasticity, clearance of Aβ and normalization of PI3K/AKT/GSK3β cell signaling in the hippocampus. This study suggests that (D-Ser2)Oxm holds promise for the prevention and treatment of AD.
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Affiliation(s)
- Zhao-Jun Wang
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China
| | - Yu-Fei Han
- Guangzhou Kingmed Diagnostics, Guangzhou, PR China
| | - Fang Zhao
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China
| | - Guang-Zhao Yang
- Department of Cardiovascular Medicine, The First Hospital of Shanxi Medical University, Taiyuan, PR China
| | - Li Yuan
- Department of Physiology, Changzhi Medical College, Changzhi, PR China
| | - Hong-Yan Cai
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, PR China
| | - Jun-Ting Yang
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China
| | - Christian Holscher
- Neuroscience research group, Henan university of Chinese medicine, Zhengzhou, PR China
| | - Jin-Shun Qi
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China.
| | - Mei-Na Wu
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China.
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12
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High-Fat Diet-Induced Obesity Causes Sex-Specific Deficits in Adult Hippocampal Neurogenesis in Mice. eNeuro 2020; 7:ENEURO.0391-19.2019. [PMID: 31871124 PMCID: PMC6946541 DOI: 10.1523/eneuro.0391-19.2019] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/26/2019] [Accepted: 12/01/2019] [Indexed: 12/13/2022] Open
Abstract
Adult hippocampal neurogenesis (AHN) is suppressed by high-fat (HF) diet and metabolic disease, including obesity and type 2 diabetes. Deficits in AHN may contribute to cognitive decline and increased risk of dementia and mood disorders, which have higher prevalence in women. However, sex differences in the effects of HF diet/metabolic disease on AHN have yet to be thoroughly investigated. Herein, male and female C57BL/6J mice were fed an HF or control (CON) diet from ∼2 to 6 months of age. After 3 months on the diet, mice were injected with 5-ethynyl-2′-deoxyuridine (EdU) then killed 4 weeks later. Cell proliferation, differentiation/maturation, and survival of new neurons in the dentate gyrus were assessed with immunofluorescence for EdU, Ki67, doublecortin (DCX), and NeuN. CON females had more proliferating cells (Ki67+) and neuroblasts/immature neurons (DCX+) compared with CON males; however, HF diet reduced these cells in females to the levels of males. Diet did not affect neurogenesis in males. Further, the numbers of proliferating cells and immature neurons were inversely correlated with both weight gain and glucose intolerance in females only. These effects were robust in the dorsal hippocampus, which supports cognitive processes. Assessment of microglia in the dentate gyrus using immunofluorescence for Iba1 and CD68 uncovered sex-specific effects of diet, which may contribute to observed differences in neurogenesis. These findings demonstrate sex-specific effects of HF diet/metabolic disease on AHN, and highlight the potential for targeting neurogenic deficits to treat cognitive decline and reduce the risk of dementia associated with these conditions, particularly in females.
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Craig SL, Gault VA, McClean S, Hamscher G, Irwin N. Effects of an enzymatically stable C-terminal hexapseudopeptide fragment peptide of xenin-25, ψ-xenin-6, on pancreatic islet function and metabolism. Mol Cell Endocrinol 2019; 496:110523. [PMID: 31352038 DOI: 10.1016/j.mce.2019.110523] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/18/2019] [Accepted: 07/24/2019] [Indexed: 12/19/2022]
Abstract
Xenin-25 undergoes rapid enzyme metabolism following secretion. Early studies demonstrated bioactivity of a C-terminal hexapeptide fragment of xenin-25, namely xenin-6, which were enhanced through introduction of a reduced N-terminal peptide bond, to yield Ψ-xenin-6. The present study was undertaken to define the biological actions and potential antidiabetic properties of Ψ-xenin-6. In vitro enzymatic stability, insulin and glucagon secretory activity, as well as effects on beta-cell survival were determined. Studies in mice were used to assess the impact of Ψ-xenin-6 on glucose homeostasis and satiety. Ψ-xenin-6 was resistant to murine plasma degradation. In BRIN-BD11 cells and isolated murine islets, Ψ-xenin-6 significantly stimulated insulin secretion, and prominently enhanced the insulinotropic actions of GIP. Xenin-6 and Ψ-xenin-6 had no impact on glucagon secretion, although xenin-6 partially reversed the glucagonotropic action of GIP. Further in vitro investigations revealed that, similar to GLP-1, Ψ-xenin-6 significantly augmented proliferation of human and rodent clonal beta-cells, whilst also fully protecting against cytokine-induced beta-cell cytotoxicity, with greater potency than xenin-25 and xenin-6. When administered to mice in combination with glucose, Ψ-xenin-6 significantly reduced glucose levels and enhanced glucose-induced insulin release, with a duration of biological action beyond 8 h. Ψ-xenin-6 also significantly enhanced the glucose-lowering action of GIP in vivo. In overnight fasted mice, Ψ-xenin-6 exhibited satiety actions at both 25 and 250 nmol/kg. These data demonstrates that Ψ-xenin-6 is a metabolically stable C-terminal fragment analogue of xenin-25, with a metabolic action profile that merits further study as a potential antidiabetic compound.
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Affiliation(s)
- S L Craig
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - V A Gault
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - S McClean
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - G Hamscher
- Institute of Food Chemistry and Food Biotechnology, Justus Liebig University Giessen, Germany
| | - N Irwin
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK.
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Pathak V, Pathak NM, O'Neill CL, Guduric-Fuchs J, Medina RJ. Therapies for Type 1 Diabetes: Current Scenario and Future Perspectives. CLINICAL MEDICINE INSIGHTS-ENDOCRINOLOGY AND DIABETES 2019; 12:1179551419844521. [PMID: 31105434 PMCID: PMC6501476 DOI: 10.1177/1179551419844521] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 03/26/2019] [Indexed: 02/06/2023]
Abstract
Type 1 diabetes (T1D) is caused by autoimmune destruction of insulin-producing β cells located in the endocrine pancreas in areas known as islets of Langerhans. The current standard-of-care for T1D is exogenous insulin replacement therapy. Recent developments in this field include the hybrid closed-loop system for regulated insulin delivery and long-acting insulins. Clinical studies on prediction and prevention of diabetes-associated complications have demonstrated the importance of early treatment and glucose control for reducing the risk of developing diabetic complications. Transplantation of primary islets offers an effective approach for treating patients with T1D. However, this strategy is hampered by challenges such as the limited availability of islets, extensive death of islet cells, and poor vascular engraftment of islets post-transplantation. Accordingly, there are considerable efforts currently underway for enhancing islet transplantation efficiency by harnessing the beneficial actions of stem cells. This review will provide an overview of currently available therapeutic options for T1D, and discuss the growing evidence that supports the use of stem cell approaches to enhance therapeutic outcomes.
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Affiliation(s)
- Varun Pathak
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Nupur Madhur Pathak
- The SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, Coleraine, United Kingdom
| | - Christina L O'Neill
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Jasenka Guduric-Fuchs
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Reinhold J Medina
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
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15
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Cellular and Molecular Differences Between Area CA1 and the Dentate Gyrus of the Hippocampus. Mol Neurobiol 2019; 56:6566-6580. [PMID: 30874972 DOI: 10.1007/s12035-019-1541-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/27/2019] [Indexed: 12/16/2022]
Abstract
A distinct feature of the hippocampus of the brain is its unidirectional tri-synaptic pathway originating from the entorhinal cortex and projecting to the dentate gyrus (DG) then to area CA3 and subsequently, area CA1 of the Ammon's horn. Each of these areas of the hippocampus has its own cellular structure and distinctive function. The principal neurons in these areas are granule cells in the DG and pyramidal cells in the Ammon's horn's CA1 and CA3 areas with a vast network of interneurons. This review discusses the fundamental differences between the CA1 and DG areas regarding cell morphology, synaptic plasticity, signaling molecules, ability for neurogenesis, vulnerability to various insults and pathologies, and response to pharmacological agents.
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16
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Pathak NM, Pathak V, Gault VA, McClean S, Irwin N, Flatt PR. Novel dual incretin agonist peptide with antidiabetic and neuroprotective potential. Biochem Pharmacol 2018; 155:264-274. [PMID: 30028989 DOI: 10.1016/j.bcp.2018.07.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 07/16/2018] [Indexed: 12/11/2022]
Abstract
Glucose-dependent insulinotropic hormone (GIP) and glucagon-like peptide-1 (GLP-1) are incretin hormones that exert an array of beneficial actions on metabolism and cognitive function. GLP-1-based therapeutics have been highly successful in terms of obesity and diabetes management, however GIP therapies have found no clinical utility to date. In the present study we describe, for the first time, the therapeutic effectiveness of a novel GIP/GLP-1 hybrid peptide based on the amino acid sequences of GIP, GLP-1 and the clinically approved GLP-1 mimetic, exendin-4. The hybrid peptide, N-ac(d-Ala2)GIP/GLP-1-exe, was enzymatically stable for up to 12 h when incubated with DPP-4. N-ac(d-Ala2)GIP/GLP-1-exe significantly (P < 0.001) stimulated insulin secretion from BRIN-BD11 cells and isolated mouse islets, and evoked dose-dependent increases (P < 0.001) in cAMP production in both GIP-R and GLP-1-R transfected cells. In mice, injection of the hybrid in combination with glucose significantly (P < 0.001) reduced glucose and increased insulin concentrations, with metabolic actions evident (P < 0.05) 8 h post-injection. Twice-daily injection of N-ac(d-Ala2)GIP/GLP-1-exe to high fat fed (HFF) mice for 28 days significantly (P < 0.05-P < 0.001) reduced body weight, HbA1c, circulating glucose and insulin concentrations. Furthermore, both oral and i.p. glucose tolerance were improved (P < 0.001) and insulin sensitivity enhanced. The hybrid peptide also increased (P < 0.05-P < 0.001) beta cell number, islet area, pancreatic insulin content and islet insulin secretory responsiveness in HFF mice. Finally, N-ac(d-Ala2)GIP/GLP-1-exe treated mice exhibited improved (P < 0.01) recognition memory which was accompanied by enhanced (P < 0.05-P < 0.001) hippocampal neurogenesis, synapse formation and reduced neuronal oxidative stress. These data demonstrate for the first time the beneficial actions of the novel GIP/GLP-1 hybrid, N-ac(d-Ala2)GIP/GLP-1-exe, on glucose homeostasis and memory function in diabetes.
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Affiliation(s)
- N M Pathak
- The SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, UK
| | - V Pathak
- The SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, UK
| | - V A Gault
- The SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, UK
| | - S McClean
- The SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, UK
| | - N Irwin
- The SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, UK.
| | - P R Flatt
- The SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, UK
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17
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Optimization of peptide-based polyagonists for treatment of diabetes and obesity. Bioorg Med Chem 2018; 26:2873-2881. [DOI: 10.1016/j.bmc.2017.10.047] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 10/31/2017] [Indexed: 12/28/2022]
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18
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Holst JJ, Albrechtsen NJW, Gabe MBN, Rosenkilde MM. Oxyntomodulin: Actions and role in diabetes. Peptides 2018; 100:48-53. [PMID: 29412831 DOI: 10.1016/j.peptides.2017.09.018] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 09/26/2017] [Accepted: 09/28/2017] [Indexed: 12/19/2022]
Abstract
Oxyntomodulin is a product of the glucagon precursor, proglucagon, produced and released from the endocrine L-cells of the gut after enzymatic processing by the precursor prohormone convertase 1/3. It corresponds to the proglucagon sequence 33-69 and thus contains the entire glucagon sequence plus a C-terminal octapeptide, comprising in total 37 amino acids. As might have been expected, it has glucagon-like bioactivity, but also and more surprisingly also activates the receptor for GLP-1. This has given the molecule an interesting status as a glucagon-GLP-1 co-agonist, which is currently attracting considerable interest for its potential in the treatment of diabetes and obesity. Here, we provide an update on oxyntomodulin with a focus on its potential role in metabolic diseases.
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Affiliation(s)
- Jens J Holst
- Department of Biomedical Sciences & Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences & Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Maria Buur Nordskov Gabe
- Department of Biomedical Sciences & Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mette Marie Rosenkilde
- Department of Biomedical Sciences & Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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19
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Li Y, Li L, Hölscher C. Incretin-based therapy for type 2 diabetes mellitus is promising for treating neurodegenerative diseases. Rev Neurosci 2018; 27:689-711. [PMID: 27276528 DOI: 10.1515/revneuro-2016-0018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/02/2016] [Indexed: 12/13/2022]
Abstract
Incretin hormones include glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Due to their promising action on insulinotropic secretion and improving insulin resistance (IR), incretin-based therapies have become a new class of antidiabetic agents for the treatment of type 2 diabetes mellitus (T2DM). Recently, the links between neurodegenerative diseases and T2DM have been identified in a number of studies, which suggested that shared mechanisms, such as insulin dysregulation or IR, may underlie these conditions. Therefore, the effects of incretins in neurodegenerative diseases have been extensively investigated. Protease-resistant long-lasting GLP-1 mimetics such as lixisenatide, liraglutide, and exenatide not only have demonstrated promising effects for treating neurodegenerative diseases in preclinical studies but also have shown first positive results in Alzheimer's disease (AD) and Parkinson's disease (PD) patients in clinical trials. Furthermore, the effects of other related incretin-based therapies such as GIP agonists, dipeptidyl peptidase-IV (DPP-IV) inhibitors, oxyntomodulin (OXM), dual GLP-1/GIP, and triple GLP-1/GIP/glucagon receptor agonists on neurodegenerative diseases have been tested in preclinical studies. Incretin-based therapies are a promising approach for treating neurodegenerative diseases.
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20
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A high fat diet-induced decrease in hippocampal newly-born neurons of male mice is exacerbated by mild psychological stress using a Communication Box. J Affect Disord 2017; 209:209-216. [PMID: 27930914 DOI: 10.1016/j.jad.2016.11.046] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 10/26/2016] [Accepted: 11/15/2016] [Indexed: 01/25/2023]
Abstract
BACKGROUND Obese persons have a higher incidence of depression than healthy-weight persons. Several studies indicated that the exposure to a high fat diet (HFD) results in a decrease in hippocampal neurogenesis, which leads to higher stress response and stress-induced depression. Although stress is a risk factor for obesity and depression, no studies to date have investigated the effect of stress on the hippocampal neurogenesis of HFD-induced obese animals. The aim of this study was to elucidate whether or not obese HFD-fed mice are vulnerable to stress-induced depression by investigating hippocampal neurogenesis. METHODS Sixty-four male ICR mice (four weeks of age) were fed a control (N=24) or 45%HFD (N=40) for seven weeks. Of the HFD-fed group, twenty-four mice met the criteria for "diet-induced obesity". The animals were then exposed to three consecutive days of psychological stress using a Communication Box. Half were sacrificed to evaluate the physiological changes, and the other half were perfused to quantify hippocampal neuroblasts/immature neurons by the estimation of doublecortin-immunopositive cells. RESULTS In the HFD-fed mice, psychological stress resulted in increases in caloric intake and visceral adipose tissue and a significant decrease in doublecortin-positive cells in the dentate gyrus; however, no such differences were found in the control diet-fed group. Limitations Further study using other neurogenic markers to assess the stage-specific changes in hippocampal neurogenesis will be required CONCLUSIONS: Our findings suggest that an HFD-induced decrease in hippocampal newly-born neurons leads to stress vulnerability, which may contribute to a high risk of stress-induced depression for obese persons.
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Cao Y, Yan Z, Zhou T, Wang G. SIRT1 Regulates Cognitive Performance and Ability of Learning and Memory in Diabetic and Nondiabetic Models. J Diabetes Res 2017; 2017:7121827. [PMID: 29164153 PMCID: PMC5661098 DOI: 10.1155/2017/7121827] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 08/08/2017] [Indexed: 12/15/2022] Open
Abstract
Type 2 diabetes mellitus is a complex age-related metabolic disease. Cognitive dysfunction and learning and memory deficits are main characteristics of age-related metabolic diseases in the central nervous system. The underlying mechanisms contributing to cognitive decline are complex, especially cognitive dysfunction associated with type 2 diabetes mellitus. SIRT1, as one of the modulators in insulin resistance, is indispensable for learning and memory. In the present study, deacetylation, oxidative stress, mitochondrial dysfunction, inflammation, microRNA, and tau phosphorylation are considered in the context of mechanism and significance of SIRT1 in learning and memory in diabetic and nondiabetic murine models. In addition, future research directions in this field are discussed, including therapeutic potential of its activator, resveratrol, and application of other compounds in cognitive improvement. Our findings suggest that SIRT1 might be a potential therapeutic target for the treatment of cognitive impairment induced by type 2 diabetes mellitus.
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Affiliation(s)
- Yue Cao
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Zi Yan
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Tong Zhou
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Guixia Wang
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin, China
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22
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Green AD, Vasu S, Moffett RC, Flatt PR. Co-culture of clonal beta cells with GLP-1 and glucagon-secreting cell line impacts on beta cell insulin secretion, proliferation and susceptibility to cytotoxins. Biochimie 2016; 125:119-25. [DOI: 10.1016/j.biochi.2016.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 03/21/2016] [Indexed: 12/22/2022]
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