1
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Tang D, Du B, Wang X, Nian F, Shi Z. Supplementation of amylase or amylase + xylanase improves performance and metabolism of broilers fed with diets containing newly harvested maize. Anim Biotechnol 2023; 34:4316-4336. [PMID: 36691753 DOI: 10.1080/10495398.2022.2149544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
How supplementation with amylase or amylase + xylanase in newly harvested maize-based diets affects broiler nutrient metabolism and performance is unclear. Thus, this study evaluated whether the supplementation of amylase (CN) or amylase + xylanase (CAX) improves performance and metabolism of broilers fed with newly harvested maize-based diets during a 6-week production. The results showed that the body weight gain of broilers fed with CA or CAX diet was higher than that with the control (CN) diet at 1-21 d of age; however, an opposite trend was observed for feed/gain (p < 0.05). Furthermore, 150, 64 and 35 different metabolites were found between CA/CN, CAX/CN and CAX/CA, respectively. Overall, amylase supplementation improved broiler growth performance at 1-21 d of age, and the positive effects of amylase on nutrient utilization were mostly related to nicotinate, retinol and glutathione metabolism improvement. Moreover, CAX diet increased apparent metabolizable energy and growth performance of broilers at 22-42 d of age, and the difference might be related to sphingolipid, porphyrin and chlorophyll metabolism regulation. The findings prove amylase + xylanase supplementation is an effective method to improve the nutritional value of newly harvested maize for broilers.
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Affiliation(s)
- Defu Tang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, P. R. China
| | - Baolong Du
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, P. R. China
| | - Xuan Wang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, P. R. China
| | - Fang Nian
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, P. R. China
| | - Zhaoguo Shi
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, P. R. China
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2
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Liu X, Peng Y, Xu Y, He G, Liang J, Masanja F, Yang K, Xu X, Deng Y, Zhao L. Responses of digestive metabolism to marine heatwaves in pearl oysters. MARINE POLLUTION BULLETIN 2023; 186:114395. [PMID: 36455501 DOI: 10.1016/j.marpolbul.2022.114395] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/16/2022] [Accepted: 11/19/2022] [Indexed: 06/17/2023]
Abstract
Marine heatwaves (MHWs) have increased in intensity and frequency in global oceans, causing deleterious effects on many marine organisms and ecosystems they support. Bivalves are among the most vulnerable taxonomic groups to intensifying MHWs, yet little is known about the underlying mechanisms. Here, we investigated the impact of MHWs on the digestive metabolism of pearl oysters (Pinctada maxima). Two moderate and severe scenarios of MHWs were performed by increasing seawater temperature respectively from 24 °C to 28 °C and 32 °C for 3 days. When subjected to MHWs and with increasing intensity, pearl oysters significantly enhanced their digestive enzymatic activities, such as lipase and amylase. LC-MS-based metabolomics revealed negative responses in the lipid metabolism (e.g., steroid biosynthesis, glycerophospholipid metabolism, and sphingolipid metabolism), the amino acid metabolism (e.g., glutamate, histidine, arginine, and proline), and the B-vitamins metabolism. These findings indicate that the digestive metabolism of marine bivalves can likely succumb to intensifying MHWs events.
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Affiliation(s)
- Xiaolong Liu
- Fisheries College, Guangdong Ocean University, Zhanjiang, China
| | - Yalan Peng
- Zhuhai Central Station of Marine Environmental Monitoring, Ministry of Natural Resources, Zhuhai, China.
| | - Yang Xu
- Fisheries College, Guangdong Ocean University, Zhanjiang, China
| | - Guixiang He
- Fisheries College, Guangdong Ocean University, Zhanjiang, China
| | - Jian Liang
- Fisheries College, Guangdong Ocean University, Zhanjiang, China; Department of Fisheries, Tianjin Agricultural University, Tianjin, China
| | | | - Ke Yang
- Fisheries College, Guangdong Ocean University, Zhanjiang, China
| | - Xin Xu
- Fisheries College, Guangdong Ocean University, Zhanjiang, China
| | - Yuewen Deng
- Fisheries College, Guangdong Ocean University, Zhanjiang, China
| | - Liqiang Zhao
- Fisheries College, Guangdong Ocean University, Zhanjiang, China.
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3
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Gurgul-Convey E. To Be or Not to Be: The Divergent Action and Metabolism of Sphingosine-1 Phosphate in Pancreatic Beta-Cells in Response to Cytokines and Fatty Acids. Int J Mol Sci 2022; 23:ijms23031638. [PMID: 35163559 PMCID: PMC8835924 DOI: 10.3390/ijms23031638] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/24/2022] [Accepted: 01/27/2022] [Indexed: 01/02/2023] Open
Abstract
Sphingosine-1 phosphate (S1P) is a bioactive sphingolipid with multiple functions conveyed by the activation of cell surface receptors and/or intracellular mediators. A growing body of evidence indicates its important role in pancreatic insulin-secreting beta-cells that are necessary for maintenance of glucose homeostasis. The dysfunction and/or death of beta-cells lead to diabetes development. Diabetes is a serious public health burden with incidence growing rapidly in recent decades. The two major types of diabetes are the autoimmune-mediated type 1 diabetes (T1DM) and the metabolic stress-related type 2 diabetes (T2DM). Despite many differences in the development, both types of diabetes are characterized by chronic hyperglycemia and inflammation. The inflammatory component of diabetes remains under-characterized. Recent years have brought new insights into the possible mechanism involved in the increased inflammatory response, suggesting that environmental factors such as a westernized diet may participate in this process. Dietary lipids, particularly palmitate, are substrates for the biosynthesis of bioactive sphingolipids. Disturbed serum sphingolipid profiles were observed in both T1DM and T2DM patients. Many polymorphisms were identified in genes encoding enzymes of the sphingolipid pathway, including sphingosine kinase 2 (SK2), the S1P generating enzyme which is highly expressed in beta-cells. Proinflammatory cytokines and free fatty acids have been shown to modulate the expression and activity of S1P-generating and S1P-catabolizing enzymes. In this review, the similarities and differences in the action of extracellular and intracellular S1P in beta-cells exposed to cytokines or free fatty acids will be identified and the outlook for future research will be discussed.
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Affiliation(s)
- Ewa Gurgul-Convey
- Institute of Clinical Biochemistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
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4
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Xin MZ, Shi YY, Li CS, Zuo LH, Li N, Liu LW, Ma HX, Du QZ, Xue P, Sun Z, Zhao HY. Metabolomics and Transcriptomics Analysis on Metabolic Characteristics of Oral Lichen Planus. Front Oncol 2021; 11:769163. [PMID: 34737967 PMCID: PMC8560742 DOI: 10.3389/fonc.2021.769163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/04/2021] [Indexed: 11/13/2022] Open
Abstract
Objective To explore metabolic biomarkers related to erosive and reticulated oral lichen planus (OLP) by non-targeted metabolomics methods and correlate metabolites with gene expression, and to investigate the pathological network pathways of OLP from the perspective of metabolism. Methods A total of 153 individuals were enrolled in this study, including 50 patients with erosive oral lichen planus (EOLP), 51 patients with reticulated oral lichen planus (ROLP), and 52 healthy controls (HC). The ultra-high-performance liquid chromatography quadrupole-Orbitrap high-resolution accurate mass spectrometry (UHPLC/Q-Orbitrap HRMS) was used to analyze the metabolites of 40 EOLP, 40 ROLP, and 40 HC samples, and the differential metabolic biomarkers were screened and identified. The regulatory genes were further screened through the shared metabolites between EOLP and ROLP, and cross-correlated with the OLP-related differential genes in the network database. A “gene-metabolite” network was constructed after finding the key differential genes. Finally, the diagnostic efficiency of the biomarkers was verified in the validation set and a diagnostic model was constructed. Result Compared with HC group, a total of 19 and 25 differential metabolites were identified in the EOLP group and the ROLP group, respectively. A total of 14 different metabolites were identified between EOLP and ROLP. Two diagnostic models were constructed based on these differential metabolites. There are 14 differential metabolites shared by EOLP and ROLP. The transcriptomics data showed 756 differentially expressed genes, and the final crossover network showed that 19 differential genes were associated with 12 metabolites. Enrichment analysis showed that alanine, aspartate and glutamate metabolism were closely associated with the pathogenesis of OLP. Conclusion The metabolic change of different types of OLP were clarified. The potential gene perturbation of OLP was provided. This study provided a strong support for further exploration of the pathogenic mechanism of OLP.
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Affiliation(s)
- Ming-Zhe Xin
- Department of Oral Emergency, The First Affiliated Hospital of Zhengzhou University· Stomatological Hospital of Henan Province, Zhengzhou, China.,School and Hospital of Stomatology of Zhengzhou University, Zhengzhou, China
| | - Ying-Ying Shi
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Henan Engineering Research Center of Clinical Mass Spectrometry for Precision Medicine, Zhengzhou, China
| | - Chun-Shen Li
- Department of Oral Emergency, The First Affiliated Hospital of Zhengzhou University· Stomatological Hospital of Henan Province, Zhengzhou, China.,School and Hospital of Stomatology of Zhengzhou University, Zhengzhou, China
| | - Li-Hua Zuo
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Henan Engineering Research Center of Clinical Mass Spectrometry for Precision Medicine, Zhengzhou, China
| | - Na Li
- Department of Prosthodontics, The First Affiliated Hospital of Zhengzhou University· Stomatological Hospital of Henan Province, Zhengzhou, China
| | - Li-Wei Liu
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Henan Engineering Research Center of Clinical Mass Spectrometry for Precision Medicine, Zhengzhou, China
| | - He-Xin Ma
- Department of Oral Emergency, The First Affiliated Hospital of Zhengzhou University· Stomatological Hospital of Henan Province, Zhengzhou, China.,School and Hospital of Stomatology of Zhengzhou University, Zhengzhou, China
| | - Qiu-Zheng Du
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Henan Engineering Research Center of Clinical Mass Spectrometry for Precision Medicine, Zhengzhou, China
| | - Peng Xue
- Health Management Center, The First Affiliated Hospital of Zhengzhou University· Stomatological Hospital of Henan Province, Zhengzhou, China
| | - Zhi Sun
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Henan Engineering Research Center of Clinical Mass Spectrometry for Precision Medicine, Zhengzhou, China
| | - Hong-Yu Zhao
- Department of Oral Emergency, The First Affiliated Hospital of Zhengzhou University· Stomatological Hospital of Henan Province, Zhengzhou, China.,School and Hospital of Stomatology of Zhengzhou University, Zhengzhou, China
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5
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Sphingolipids in Type 1 Diabetes: Focus on Beta-Cells. Cells 2020; 9:cells9081835. [PMID: 32759843 PMCID: PMC7465050 DOI: 10.3390/cells9081835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/01/2020] [Accepted: 08/03/2020] [Indexed: 12/28/2022] Open
Abstract
Type 1 diabetes (T1DM) is a chronic autoimmune disease, with a strong genetic background, leading to a gradual loss of pancreatic beta-cells, which secrete insulin and control glucose homeostasis. Patients with T1DM require life-long substitution with insulin and are at high risk for development of severe secondary complications. The incidence of T1DM has been continuously growing in the last decades, indicating an important contribution of environmental factors. Accumulating data indicates that sphingolipids may be crucially involved in T1DM development. The serum lipidome of T1DM patients is characterized by significantly altered sphingolipid composition compared to nondiabetic, healthy probands. Recently, several polymorphisms in the genes encoding the enzymatic machinery for sphingolipid production have been identified in T1DM individuals. Evidence gained from studies in rodent islets and beta-cells exposed to cytokines indicates dysregulation of the sphingolipid biosynthetic pathway and impaired function of several sphingolipids. Moreover, a number of glycosphingolipids have been suggested to act as beta-cell autoantigens. Studies in animal models of autoimmune diabetes, such as the Non Obese Diabetic (NOD) mouse and the LEW.1AR1-iddm (IDDM) rat, indicate a crucial role of sphingolipids in immune cell trafficking, islet infiltration and diabetes development. In this review, the up-to-date status on the findings about sphingolipids in T1DM will be provided, the under-investigated research areas will be identified and perspectives for future studies will be given.
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6
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Skog O, Korsgren O. On the dynamics of the human endocrine pancreas and potential consequences for the development of type 1 diabetes. Acta Diabetol 2020; 57:503-511. [PMID: 31520124 PMCID: PMC7093340 DOI: 10.1007/s00592-019-01420-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 09/04/2019] [Indexed: 12/14/2022]
Abstract
Little is known about the human islet life span, and beta-cell neogenesis is generally considered rare in adults. However, based on available data on beta-cell proliferation, calculations can be made suggesting that the dynamics of the endocrine pancreas is considerable even during adulthood, with islet neogenesis and a sustained increase in size of already formed islets. Islet-associated hemorrhages, frequently observed in most mammals including humans, could account for a considerable loss of islet parenchyma balancing the constant beta-cell proliferation. Notably, in subjects with type 1 diabetes, periductal accumulation of leukocytes and fibrosis is frequently observed, findings that are likely to negatively affect islet neogenesis from endocrine progenitor cells present in the periductal area. Impaired neogenesis would disrupt the balance, result in loss of islet mass, and eventually lead to beta-cell deficiency and compromised glucose metabolism, with increased islet workload and blood perfusion of remaining islets. These changes would impose initiation of a vicious circle further increasing the frequency of vascular events and hemorrhages within remaining islets until the patient eventually loses all beta-cells and becomes c-peptide negative.
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Affiliation(s)
- Oskar Skog
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
| | - Olle Korsgren
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
- Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
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7
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He Y, Shi B, Zhao X, Sui J. Sphingosine-1-phosphate induces islet β-cell proliferation and decreases cell apoptosis in high-fat diet/streptozotocin diabetic mice. Exp Ther Med 2019; 18:3415-3424. [PMID: 31602216 PMCID: PMC6777293 DOI: 10.3892/etm.2019.7999] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 08/08/2019] [Indexed: 12/17/2022] Open
Abstract
Sphingosine-1-phosphate (S1P) has been reported to enhance the function of islet β-cells, providing a potential therapeutic target for diabetes mellitus. In the present study, the effects of S1P on the proliferation and apoptosis of β-cells in type 2 diabetic mice were investigated. The mice were administered intraperitoneal S1P solution daily at a dose of 20 µg/kg for three weeks. The intraperitoneal glucose tolerance test (IPGTT) and homeostatic model assessment of insulin resistance (HOMA-IR) index determination were carried out. Immunohistochemical staining was used to detect the protein expression of insulin, antigen Ki-67 and S1P receptor isoforms (S1PR1/S1PR2/S1PR3) in pancreatic islets. Compared with the diabetic control (DC) group, the IPGTT results and HOMA-IR index in the S1P treatment group were decreased. The islets in the S1P group exhibited higher insulin immunostaining intensity than the DC group, as well as higher proliferation (P<0.05) and lower apoptosis rates (P<0.05). Positive staining for the S1P receptors S1PR1, S1PR2 and S1PR3 was observed in the cytoplasm and membrane of the islet cells. S1PR1 and S1PR2 proteins showed increased expression in the S1P and DC groups compared with the normal control group (P<0.01 and P<0.05, respectively), whereas no significant difference was observed in the expression of S1PR3 among these groups. In conclusion, extracellular S1P can induce islet β-cell proliferation and decrease cell apoptosis in diabetic mice. S1P function may be mediated via S1PR1 and S1PR2; therefore, targeting S1P/S1PR signalling pathways may be a novel therapeutic strategy for diabetes mellitus.
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Affiliation(s)
- Yizhi He
- Department of Endocrinology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China.,Department of Endocrinology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Xi'an, Shaanxi 710018, P.R. China
| | - Bingyin Shi
- Department of Endocrinology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Xinrui Zhao
- Department of Immunology and Rheumatology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Jing Sui
- Department of Endocrinology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
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8
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Bowers DT, Olingy CE, Chhabra P, Langman L, Merrill PH, Linhart RS, Tanes ML, Lin D, Brayman KL, Botchwey EA. An engineered macroencapsulation membrane releasing FTY720 to precondition pancreatic islet transplantation. J Biomed Mater Res B Appl Biomater 2018; 106:555-568. [PMID: 28240814 PMCID: PMC5572559 DOI: 10.1002/jbm.b.33862] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 12/28/2016] [Accepted: 01/26/2017] [Indexed: 02/06/2023]
Abstract
Macroencapsulation is a powerful approach to increase the efficiency of extrahepatic pancreatic islet transplant. FTY720, a small molecule that activates signaling through sphingosine-1-phosphate receptors, is immunomodulatory and pro-angiogenic upon sustained delivery from biomaterials. While FTY720 (fingolimod, Gilenya) has been explored for organ transplantation, in the present work the effect of locally released FTY720 from novel nanofiber-based macroencapsulation membranes is explored for islet transplantation. We screened islet viability during culture with FTY720 and various biodegradable polymers. Islet viability is significantly reduced by the addition of high doses (≥500 ng/mL) of soluble FTY720. Among the polymers screened, islets have the highest viability when cultured with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). Therefore, PHBV was blended with polycaprolactone (PCL) for mechanical stability and electrospun into nanofibers. Islets had no detectable function ex vivo following 5 days or 12 h of subcutaneous implantation within our engineered device. Subsequently, we explored a preconditioning scheme in which islets are transplanted 2 weeks after FTY720-loaded nanofibers are implanted. This allows FTY720 to orchestrate a local regenerative milieu while preventing premature transplantation into avascular sites that contain high concentrations of FTY720. These results provide a foundation and motivation for further investigation into the use of FTY720 in preconditioning sites for efficacious islet transplantation. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 555-568, 2018.
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Affiliation(s)
- Daniel T Bowers
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, 22903
| | - Claire E Olingy
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, 30332-0363
| | - Preeti Chhabra
- Department of Surgery, University of Virginia, Charlottesville, Virginia, 22903
| | - Linda Langman
- Department of Surgery, University of Virginia, Charlottesville, Virginia, 22903
| | - Parker H Merrill
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, 22903
| | - Ritu S Linhart
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, 22903
| | - Michael L Tanes
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, 22903
| | - Dan Lin
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, 22903
| | - Kenneth L Brayman
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, 22903
- Department of Surgery, University of Virginia, Charlottesville, Virginia, 22903
| | - Edward A Botchwey
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, 22903
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, 30332-0363
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9
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Rojas-Canales D, Penko D, Myo Min KK, Parham KA, Peiris H, Haberberger RV, Pitson SM, Drogemuller C, Keating DJ, Grey ST, Coates PT, Bonder CS, Jessup CF. Local Sphingosine Kinase 1 Activity Improves Islet Transplantation. Diabetes 2017; 66:1301-1311. [PMID: 28174291 DOI: 10.2337/db16-0837] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 02/02/2017] [Indexed: 11/13/2022]
Abstract
Pancreatic islet transplantation is a promising clinical treatment for type 1 diabetes, but success is limited by extensive β-cell death in the immediate posttransplant period and impaired islet function in the longer term. Following transplantation, appropriate vascular remodeling is crucial to ensure the survival and function of engrafted islets. The sphingosine kinase (SK) pathway is an important regulator of vascular beds, but its role in the survival and function of transplanted islets is unknown. We observed that donor islets from mice deficient in SK1 (Sphk1 knockout) contain a reduced number of resident intraislet vascular endothelial cells. Furthermore, we demonstrate that the main product of SK1, sphingosine-1-phosphate, controls the migration of intraislet endothelial cells in vitro. We reveal in vivo that Sphk1 knockout islets have an impaired ability to cure diabetes compared with wild-type controls. Thus, SK1-deficient islets not only contain fewer resident vascular cells that participate in revascularization, but likely also a reduced ability to recruit new vessels into the transplanted islet. Together, our data suggest that SK1 is important for islet revascularization following transplantation and represents a novel clinical target for improving transplant outcomes.
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Affiliation(s)
- Darling Rojas-Canales
- Discipline of Medicine, The University of Adelaide, Adelaide, Australia
- Central Northern Adelaide Renal and Transplantation Services, Royal Adelaide Hospital, Adelaide, Australia
| | - Daniella Penko
- Discipline of Medicine, The University of Adelaide, Adelaide, Australia
- Central Northern Adelaide Renal and Transplantation Services, Royal Adelaide Hospital, Adelaide, Australia
| | - Kay K Myo Min
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, Australia
| | - Kate A Parham
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, Australia
| | - Heshan Peiris
- Department of Human Physiology, Flinders University, Bedford Park, Australia
- Centre for Neuroscience, Flinders University, Bedford Park, Australia
| | | | - Stuart M Pitson
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, Australia
| | - Chris Drogemuller
- Discipline of Medicine, The University of Adelaide, Adelaide, Australia
- Central Northern Adelaide Renal and Transplantation Services, Royal Adelaide Hospital, Adelaide, Australia
| | - Damien J Keating
- Department of Human Physiology, Flinders University, Bedford Park, Australia
- Centre for Neuroscience, Flinders University, Bedford Park, Australia
- South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Shane T Grey
- Garvan Medical Institute, Darlinghurst, Australia
| | - Patrick T Coates
- Discipline of Medicine, The University of Adelaide, Adelaide, Australia
- Central Northern Adelaide Renal and Transplantation Services, Royal Adelaide Hospital, Adelaide, Australia
| | - Claudine S Bonder
- Discipline of Medicine, The University of Adelaide, Adelaide, Australia
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, Australia
| | - Claire F Jessup
- Discipline of Medicine, The University of Adelaide, Adelaide, Australia
- Centre for Neuroscience, Flinders University, Bedford Park, Australia
- Department of Anatomy & Histology, Flinders University, Bedford Park, Australia
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10
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Roles of Sphingolipid Metabolism in Pancreatic β Cell Dysfunction Induced by Lipotoxicity. J Clin Med 2014; 3:646-62. [PMID: 26237395 PMCID: PMC4449690 DOI: 10.3390/jcm3020646] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 04/10/2014] [Accepted: 04/11/2014] [Indexed: 12/31/2022] Open
Abstract
Pancreatic β cells secrete insulin in order to maintain glucose homeostasis. However, various environmental stresses such as obesity have been shown to induce loss of secretory responsiveness in pancreatic β cells and pancreatic β cell apoptosis which can favor the development of type 2 diabetes (T2D). Indeed, elevated levels of free fatty acids (FFAs) have been shown to induce β cell apoptosis. Importantly, the chronic adverse effects of FFAs on β cell function and viability are potentiated in the presence of hyperglycaemia, a phenomenon that has been termed gluco-lipotoxicity. The molecular mechanisms underlying the pathogenesis of gluco-lipotoxicity in pancreatic β cells are not completely understood. Recent studies have shown that sphingolipid metabolism plays a key role in gluco-lipotoxicity induced apoptosis and loss of function of pancreatic β cells. The present review focuses on how the two main sphingolipid mediators, ceramides and sphingoid base-1-phosphates, regulate the deleterious effects of gluco-lipotoxicity on pancreatic β cells. The review highlights the role of a sphingolipid biostat on the dysregulation of β cell fate and function induced by gluco-lipotoxicity, offering the possibility of new therapeutic targets to prevent the onset of T2D.
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11
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Zhu Q, Kang J, Miao H, Feng Y, Xiao L, Hu Z, Liao DF, Huang Y, Jin J, He S. Low-dose cytokine-induced neutral ceramidase secretion from INS-1 cells via exosomes and its anti-apoptotic effect. FEBS J 2014; 281:2861-70. [PMID: 24798654 DOI: 10.1111/febs.12826] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 04/14/2014] [Accepted: 04/28/2014] [Indexed: 12/19/2022]
Abstract
It has been reported that the effect of inflammatory cytokines on β-cell destruction in type 1 diabetes is concentration-dependent. However, the underlying mechanisms remain unclear. In the present study, we found that a high concentration of cytokines promoted apoptosis in the rat β-cell line INS-1, whereas a low concentration of cytokines had no effect. We also found that cytokines at a low concentration stimulated neutral ceramidase (NCDase) release via exosomes from INS-1 cells, whereas cytokines at a high concentration inhibited NCDase release. Furthermore, the results showed that the NCDase-containing exosomes isolated from the culture medium of INS-1 cells treated with cytokines at a low concentration inhibited apoptosis induced by a high concentration of cytokines. Finally, the results also showed that the protective action of NCDase in the exosomes on apoptosis was mediated by the generation of sphingosine 1-phosphate (S1P) and its interaction with S1P receptor 2. Taken together, these findings revealed a novel NCDase-S1P-phosphate-S1P receptor 2-dependent mechanism by which a low level of inflammatory cytokines protects pancreatic β-cells from apoptosis induced by a high level of inflammatory cytokines.
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Affiliation(s)
- Qun Zhu
- Department of Endocrinology, The Second Affiliated Hospital of Nanjing Medical University, Jiangsu, China
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12
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Inhibition of ceramide de novo synthesis with myriocin affects lipid metabolism in the liver of rats with streptozotocin-induced type 1 diabetes. BIOMED RESEARCH INTERNATIONAL 2014; 2014:980815. [PMID: 24701589 PMCID: PMC3950399 DOI: 10.1155/2014/980815] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 12/27/2013] [Accepted: 12/31/2013] [Indexed: 12/11/2022]
Abstract
Nowadays diabetes is one of the most common metabolic diseases. Sphingolipids, which are vitally important constituents of intracellular signal transduction pathways, may be among the most pathogenic lipid moieties intermingled in the origin and development of diabetes. It is now well established that inhibition of de novo ceramide synthesis with myriocin exerts positive effects on lipid metabolism and glucose homeostasis in type 2 diabetes mellitus animal models. However, its influence on type I diabetes still remains unknown. Therefore, the scope of this paper is to fulfill that particular gap in our knowledge.
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13
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Amisten S, Salehi A, Rorsman P, Jones PM, Persaud SJ. An atlas and functional analysis of G-protein coupled receptors in human islets of Langerhans. Pharmacol Ther 2013; 139:359-91. [DOI: 10.1016/j.pharmthera.2013.05.004] [Citation(s) in RCA: 143] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 05/03/2013] [Indexed: 12/17/2022]
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14
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Mastrandrea LD. Role of sphingosine kinases and sphingosine 1-phosphate in mediating adipogenesis. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/jdm.2013.32009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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15
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Véret J, Coant N, Gorshkova IA, Giussani P, Fradet M, Riccitelli E, Skobeleva A, Goya J, Kassis N, Natarajan V, Portha B, Berdyshev EV, Le Stunff H. Role of palmitate-induced sphingoid base-1-phosphate biosynthesis in INS-1 β-cell survival. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:251-62. [PMID: 23085009 DOI: 10.1016/j.bbalip.2012.10.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 09/19/2012] [Accepted: 10/10/2012] [Indexed: 01/09/2023]
Abstract
Sphingoid base-1-phosphates represent a very low portion of the sphingolipid pool but are potent bioactive lipids in mammals. This study was undertaken to determine whether these lipids are produced in palmitate-treated pancreatic β cells and what role they play in palmitate-induced β cell apoptosis. Our lipidomic analysis revealed that palmitate at low and high glucose supplementation increased (dihydro)sphingosine-1-phosphate levels in INS-1 β cells. This increase was associated with an increase in sphingosine kinase 1 (SphK1) mRNA and protein levels. Over-expression of SphK1 in INS-1 cells potentiated palmitate-induced accumulation of dihydrosphingosine-1-phosphate. N,N-dimethyl-sphingosine, a potent inhibitor of SphK, potentiated β-cell apoptosis induced by palmitate whereas over-expression of SphK1 significantly reduced apoptosis induced by palmitate with high glucose. Endoplasmic reticulum (ER)-targeted SphK1 also partially inhibited apoptosis induced by palmitate. Inhibition of INS-1 apoptosis by over-expressed SphK1 was independent of sphingosine-1-phosphate receptors but was associated with a decreased formation of pro-apoptotic ceramides induced by gluco-lipotoxicity. Moreover, over-expression of SphK1 counteracted the defect in the ER-to-Golgi transport of proteins that contribute to the ceramide-dependent ER stress observed during gluco-lipotoxicity. In conclusion, our results suggest that activation of palmitate-induced SphK1-mediated sphingoid base-1-phosphate formation in the ER of β cells plays a protective role against palmitate-induced ceramide-dependent apoptotic β cell death.
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Affiliation(s)
- Julien Véret
- Université Paris Diderot, Sorbonne Paris Cité, Laboratoire de Biologie et Pathologie du Pancréas Endocrine, Unité BFA, CNRS EAC 4413, Paris, France
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16
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Egom EEA. A therapeutic approach to hyperglycaemia in the setting of acute myocardial infarction: spotlight on glucagon-like peptide 1. Ther Adv Cardiovasc Dis 2012; 6:213-9. [DOI: 10.1177/1753944712457598] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Patients with acute myocardial infarction (AMI) frequently have abnormalities of glucose metabolism and insulin resistance, both of which are associated with a poor outcome. Glucagon-like peptide 1 (GLP-1) is a naturally occurring incretin with both insulinotropic and insulinomimetic properties which not only controls glucose levels but also has potential beneficial actions on the ischaemic and failing heart. In this review we highlight the underlying pathophysiological mechanisms for the development of hyperglycaemia in AMI, speculate on the potential relationship between GLP-1 and sphingosine-1-phosphate, and review the literature on the role of GLP-1 as an important approach to treating hyperglycaemia in the setting of AMI.
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Affiliation(s)
- Emmanuel Eroume A Egom
- Hull and East Yorkshire Hospitals NHS Trust, Academic Cardiology, University of Hull, Hull, East Yorkshire HU16 5JQ, UK
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17
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Egom EEA, Mamas MA, Clark AL. The potential role of sphingolipid-mediated cell signaling in the interaction between hyperglycemia, acute myocardial infarction and heart failure. Expert Opin Ther Targets 2012; 16:791-800. [DOI: 10.1517/14728222.2012.699043] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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18
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Cantrell Stanford J, Morris AJ, Sunkara M, Popa GJ, Larson KL, Özcan S. Sphingosine 1-phosphate (S1P) regulates glucose-stimulated insulin secretion in pancreatic beta cells. J Biol Chem 2012; 287:13457-64. [PMID: 22389505 DOI: 10.1074/jbc.m111.268185] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recent studies suggest that sphingolipid metabolism is altered during type 2 diabetes. Increased levels of the sphingolipid ceramide are associated with insulin resistance. However, a role for sphingolipids in pancreatic beta cell function, or insulin production, and release remains to be established. Our studies in MIN6 cells and mouse pancreatic islets demonstrate that glucose stimulates an intracellular rise in the sphingolipid, sphingosine 1-phosphate (S1P), whereas the levels of ceramide and sphingomyelin remain unchanged. The increase in S1P levels by glucose is due to activation of sphingosine kinase 2 (SphK2). Interestingly, rises in S1P correlate with increased glucose-stimulated insulin secretion (GSIS). Decreasing S1P levels by treatment of MIN6 cells or primary islets with the sphingosine kinase inhibitor reduces GSIS. Moreover, knockdown of SphK2 alone results in decreased GSIS, whereas knockdown of the S1P phosphatase, Sgpp1, leads to a rise in GSIS. Treatment of mice with the sphingosine kinase inhibitor impairs glucose disposal due to decreased plasma insulin levels. Altogether, our data suggest that glucose activates SphK2 in pancreatic beta cells leading to a rise in S1P levels, which is important for GSIS.
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Affiliation(s)
- Jamie Cantrell Stanford
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky 40536, USA
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19
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Hasan NM, Longacre MJ, Stoker SW, Kendrick MA, Druckenbrod NR, Laychock SG, Mastrandrea LD, MacDonald MJ. Sphingosine kinase 1 knockdown reduces insulin synthesis and secretion in a rat insulinoma cell line. Arch Biochem Biophys 2011; 518:23-30. [PMID: 22155656 DOI: 10.1016/j.abb.2011.11.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 11/15/2011] [Indexed: 12/13/2022]
Abstract
To evaluate the role of sphingosine kinase 1 (SphK1) in insulin secretion, we used stable transfection to knock down the expression of the Sphk1 gene in the rat insulinoma INS-1 832/13 cell line. Cell lines with lowered Sphk1 mRNA expression and SphK1 enzyme activity (SK11 and SK14) exhibited lowered glucose- and 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid (BCH) plus glutamine-stimulated insulin release and low insulin content associated with decreases in the mRNA of the insulin 1 gene. Overexpression of the rat or human Sphk1 cDNA restored insulin secretion and total insulin content in the SK11 cell line, but not in the SK14 cell line. The Sphk1 cDNA-transfected SK14 cell line expressed significantly less SphK1 activity than the Sphk1 cDNA-transfected SK11 cells suggesting that the shRNA targeting SK14 was more effective in silencing the exogenous rat Sphk1 mRNA. The results indicate that SphK1 activity is important for insulin synthesis and secretion.
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Affiliation(s)
- N M Hasan
- Childrens Diabetes Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States
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20
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Kruit JK, Brunham LR, Verchere CB, Hayden MR. HDL and LDL cholesterol significantly influence beta-cell function in type 2 diabetes mellitus. Curr Opin Lipidol 2010; 21:178-85. [PMID: 20463468 DOI: 10.1097/mol.0b013e328339387b] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF REVIEW Patients with type 2 diabetes mellitus (T2DM) display significant abnormalities in both LDL and HDL particles. Recent data suggest that these changes in lipoprotein particles could contribute to the pathogenesis of T2DM. In this review, we focus on these abnormalities and discuss their possible impact on beta-cell function and beta-cell mass. RECENT FINDINGS Infusion of reconstituted HDL in T2DM patients improves beta-cell function, whereas carriers of loss-of-function mutations in the cholesterol transporter ABCA1, who have decreased HDL levels, have impaired beta-cell function. In addition, recent studies show that HDL protects against stress-induced beta-cell apoptosis in vitro. Finally, increasing evidence points to a role for islet inflammation in the pathogenesis of T2DM. ABCA1 and ABCG1 may also modulate these inflammatory responses, suggesting an additional pathway by which HDL may impact T2DM. SUMMARY Recent findings indicate that HDL protects beta-cells from cholesterol-induced beta-cell dysfunction, stress-induced apoptosis and islet inflammation. As the protective properties of HDL are compromised in patients with metabolic syndrome and T2DM, dysfunctional HDL metabolism could contribute to the pathogenesis of T2DM. Therapeutic normalization of both the quantity and quality of HDL particles may be a novel approach to prevent or treat T2DM.
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Affiliation(s)
- Janine K Kruit
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
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21
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Mastrandrea LD, Sessanna SM, Del Toro A, Laychock SG. ATP-independent glucose stimulation of sphingosine kinase in rat pancreatic islets. J Lipid Res 2010; 51:2171-80. [PMID: 20371493 DOI: 10.1194/jlr.m000802] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sphingosine kinase (SPHK) catalyzes sphingosine 1-phosphate production, promoting cell survival and reducing apoptosis in isolated rat pancreatic islets. Glucose, the primary islet beta-cell growth factor and insulin secretagogue, increased islet SPHK activity by 3- to 5-fold following acute (1 h) or prolonged (7 days) stimulation. Prolonged stimulation of islets with glucose induced SPHK1a and SPHK2 mRNA levels; there were no changes in SPHK protein expression. To isolate the metabolic effects of glucose on SPHK activation, islets were stimulated with glucose analogs or metabolites. 2-deoxy-D-glucose (2-DG), an analog phosphorylated by glucokinase but not an effective energy source, activated SPHK similarly to glucose. In contrast, 3-o-methylglucose (3-oMeG), which is transported but neither phosphorylated nor metabolized, did not increase islet SPHK activity. Glyceraldehyde and alpha-ketoisocaproic acid (KIC), metabolites that stimulate glycolysis and the citric acid cycle, respectively, did not activate islet SPHK. Moreover, inorganic phosphate blocked glucose-induced SPHK activation. A role for SPHK activity in beta-cell growth was confirmed when small interfering (si)SPHK2 RNA transfection reduced rat insulinoma INS-1e cell SPHK levels and activity and cell growth. Glucose induced an early and sustained increase in islet SPHK activity that was dependent on glucose phosphorylation, but independent of ATP generation or new protein biosynthesis. Glucose-supported beta-cell growth appears to be in part mediated by SPHK activity.
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Affiliation(s)
- L D Mastrandrea
- Department of Pediatrics, University at Buffalo, Buffalo, NY, USA.
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22
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Imasawa T, Koike K, Ishii I, Chun J, Yatomi Y. Blockade of sphingosine 1-phosphate receptor 2 signaling attenuates streptozotocin-induced apoptosis of pancreatic beta-cells. Biochem Biophys Res Commun 2010; 392:207-11. [PMID: 20060809 DOI: 10.1016/j.bbrc.2010.01.016] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Accepted: 01/06/2010] [Indexed: 12/31/2022]
Abstract
Sphingosine 1-phosphate (S1P) is a potent sphingolipid mediator that acts through five cognate G protein-coupled receptors (S1P(1)-S1P(5)) and regulates many critical biological processes. Recent studies indicated that S1P at nanomolar concentrations significantly reduces cytokine-induced apoptosis of pancreatic beta-cells in which genes for S1P(1)-S1P(4) are co-expressed. However, the S1P receptor subtype(s) involved in this effect remains to be clarified. In this study, we investigated the potential role of S1P(2) in streptozotocin (STZ)-induced apoptosis of pancreatic beta-cells and progression of diabetes. S1P(2)-deficient (S1P(2)(-/-)) mice displayed a greater survive ability, lower blood glucose levels, and smaller numbers of TUNEL-positive apoptotic beta-cells to administration of a high dose of STZ than wild-type (WT) mice. S1P(2)(-/-) mice showed higher insulin/glucose ratios (an index of relative insulin deficiency) and larger insulin-positive islet areas to administration of a low dose of STZ than WT mice. Moreover, administration of JTE-013, a S1P(2)-specific antagonist, to WT mice ameliorated STZ-induced blood glucose elevation and reduced the incidence of diabetes. Our findings indicate that blockade of S1P(2) signaling attenuates STZ-induced apoptosis of pancreatic beta-cells and decreases the incidence of diabetes.
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Affiliation(s)
- Toshiyuki Imasawa
- Department of Internal Medicine, Division of Immunopathology, Clinical Research Center, Chiba-East National Hospital, 673 Nitona, Chuoh, Chiba 260-8712, Japan.
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23
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You H, Laychock SG. Atrial natriuretic peptide promotes pancreatic islet beta-cell growth and Akt/Foxo1a/cyclin D2 signaling. Endocrinology 2009; 150:5455-65. [PMID: 19837876 DOI: 10.1210/en.2009-0468] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The adult differentiated insulin-secreting pancreatic islet beta-cell experiences slow growth. This study shows that atrial natriuretic peptide (ANP) stimulates cell proliferation and [(3)H]thymidine incorporation in INS-1E glucose-sensitive rat beta-cell line cells and isolated rat islet DNA. In addition, cGMP, the second messenger of natriuretic peptide receptors (NPR) A and B, stimulated islet DNA biosynthesis. The NPR-A receptor was expressed in INS-1E cells and islets. ANP-stimulated INS-1E cell DNA biosynthesis was blocked by preincubation with LY294002 (50 microM), an inhibitor of phosphatidylinositol 3'-kinase (PI3K). An indicator of cell cycle progression, cyclin D2 mRNA was increased by 2- to 3-fold in ANP- or 8-Br-cGMP-treated INS-1E cells and islets, and these responses were inhibited by LY294002. ANP and 8-Br-cGMP stimulated the phosphorylation of Akt and Foxo1a in INS-1E cells and islets, and LY294002 inhibited these responses. In contrast, ANP reduced the levels of phospho-ERK in INS-1E cells. Pancreas duodenum homeobox-1 (PDX-1) is essential for pancreas development, insulin production, and glucose homeostasis, and ANP increased PDX-1 mRNA levels by 2- to 3-fold in INS-1E cells and islets. The levels of glucokinase mRNA in islets and INS-1E cells were also increased in response to ANP. The evidence suggests that pancreatic beta-cell NPR-A stimulation results in activation of a growth-promoting signaling pathway that includes PI3K/Akt/Foxo1a/cyclin D2. These data support the conclusion that the activation of Akt by ANP or 8-Br-cGMP promotes cyclin D2, PDX-1, and glucokinase transcription by phosphorylating and restricting Foxo1a activity.
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Affiliation(s)
- Hui You
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York 14214, USA
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24
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Rütti S, Ehses JA, Sibler RA, Prazak R, Rohrer L, Georgopoulos S, Meier DT, Niclauss N, Berney T, Donath MY, von Eckardstein A. Low- and high-density lipoproteins modulate function, apoptosis, and proliferation of primary human and murine pancreatic beta-cells. Endocrinology 2009; 150:4521-30. [PMID: 19628574 DOI: 10.1210/en.2009-0252] [Citation(s) in RCA: 171] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A low high-density lipoprotein (HDL) plasma concentration and the abundance of small dense low-density lipoproteins (LDL) are risk factors for developing type 2 diabetes. We therefore investigated whether HDL and LDL play a role in the regulation of pancreatic islet cell apoptosis, proliferation, and secretory function. Isolated mouse and human islets were exposed to plasma lipoproteins of healthy human donors. In murine and human beta-cells, LDL decreased both proliferation and maximal glucose-stimulated insulin secretion. The comparative analysis of beta-cells from wild-type and LDL receptor-deficient mice revealed that the inhibitory effect of LDL on insulin secretion but not proliferation requires the LDL receptor. HDL was found to modulate the survival of both human and murine islets by decreasing basal as well as IL-1beta and glucose-induced apoptosis. IL-1beta-induced beta-cell apoptosis was also inhibited in the presence of either the delipidated protein or the deproteinated lipid moieties of HDL, apolipoprotein A1 (the main protein component of HDL), or sphingosine-1-phosphate (a bioactive sphingolipid mostly carried by HDL). In murine beta-cells, the protective effect of HDL against IL-1beta-induced apoptosis was also observed in the absence of the HDL receptor scavenger receptor class B type 1. Our data show that both LDL and HDL affect function or survival of beta-cells and raise the question whether dyslipidemia contributes to beta-cell failure and hence the manifestation and progression of type 2 diabetes mellitus.
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Affiliation(s)
- Sabine Rütti
- Division of Endocrinology and Diabetes, University Hospital of Zürich, Zurich 8091, Switzerland
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25
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Holland WL, Summers SA. Sphingolipids, insulin resistance, and metabolic disease: new insights from in vivo manipulation of sphingolipid metabolism. Endocr Rev 2008; 29:381-402. [PMID: 18451260 PMCID: PMC2528849 DOI: 10.1210/er.2007-0025] [Citation(s) in RCA: 419] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Obesity and dyslipidemia are risk factors for metabolic disorders including diabetes and cardiovascular disease. Sphingolipids such as ceramide and glucosylceramides, while being a relatively minor component of the lipid milieu in most tissues, may be among the most pathogenic lipids in the onset of the sequelae associated with excess adiposity. Circulating factors associated with obesity (e.g., saturated fatty acids, inflammatory cytokines) selectively induce enzymes that promote sphingolipid synthesis, and lipidomic profiling reveals relationships between tissue sphingolipid levels and certain metabolic diseases. Moreover, studies in cultured cells and isolated tissues implicate sphingolipids in certain cellular events associated with diabetes and cardiovascular disease, including insulin resistance, pancreatic beta-cell failure, cardiomyopathy, and vascular dysfunction. However, definitive evidence that sphingolipids contribute to insulin resistance, diabetes, and atherosclerosis has come only recently, as researchers have found that pharmacological inhibition or genetic ablation of enzymes controlling sphingolipid synthesis in rodents ameliorates each of these conditions. Herein we will review the role of ceramide and other sphingolipid metabolites in insulin resistance, beta-cell failure, cardiomyopathy, and vascular dysfunction, focusing on these in vivo studies that identify enzymes controlling sphingolipid metabolism as therapeutic targets for combating metabolic disease.
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Affiliation(s)
- William L Holland
- Division of Endocrinology, Metabolism, and Diabetes, Department of Internal Medicine, University of Utah, Salt Lake City, Utah 84132, USA
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26
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Alewijnse AE, Peters SLM. Sphingolipid signalling in the cardiovascular system: good, bad or both? Eur J Pharmacol 2008; 585:292-302. [PMID: 18420192 DOI: 10.1016/j.ejphar.2008.02.089] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Revised: 01/21/2008] [Accepted: 02/06/2008] [Indexed: 12/25/2022]
Abstract
Sphingolipids are biologically active lipids that play important roles in various cellular processes and the sphingomyelin metabolites ceramide, sphingosine and sphingosine-1-phosphate can act as signalling molecules in most cell types. With the recent development of the immunosuppressant drug FTY720 (Fingolimod) which after phosphorylation in vivo acts as a sphingosine-1-phosphate receptor agonist, research on the role of sphingolipids in the immune and other organ systems was triggered enormously. Since it was reported that FTY720 induced a modest, but significant transient decrease in heart rate in animals and humans, the question was raised which pharmacological properties of drugs targeting sphingolipid signalling will affect cardiovascular function in vivo. The answer to this question will most likely also indicate what type of drug could be used to treat cardiovascular disease. The latter is becoming increasingly important because of the increasing population carrying characteristics of the metabolic syndrome. This syndrome is, amongst others, characterized by obesity, hypertension, atherosclerosis and diabetes. As such, individuals with this syndrome are at increased risk of heart disease. Now numerous studies have investigated sphingolipid effects in the cardiovascular system, can we speculate whether certain sphingolipids under specific conditions are good, bad or maybe both? In this review we will give a brief overview of the pathophysiological role of sphingolipids in cardiovascular disease. In addition, we will try to answer how drugs that target sphingolipid signalling will potentially influence cardiovascular function and whether these drugs would be useful to treat cardiovascular disease.
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Affiliation(s)
- Astrid E Alewijnse
- Department of Pharmacology and Pharmacotherapy, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
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27
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Truong W, Emamaullee JA, Merani S, Anderson CC, James Shapiro AM. Human islet function is not impaired by the sphingosine-1-phosphate receptor modulator FTY720. Am J Transplant 2007; 7:2031-8. [PMID: 17617868 DOI: 10.1111/j.1600-6143.2007.01880.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Clinical islet transplantation for type 1 diabetes mellitus currently requires potent immunosuppressive drugs, which limits the procedure to the most severe forms of the disease, and many of the drugs are directly beta-cell toxic. A class of compounds called sphingosine-1-phosphate receptor modulators has been explored in transplantation and shown to be highly effective in multiple sclerosis and other autoimmune conditions. While FTY720, the first drug in this class, may not move forward initially in transplantation, this class requires detailed investigation to assess direct impact upon human beta-cell function and survival. We set out to evaluate the effects of FTY720 on human islets in vitro by investigating glucose-stimulated insulin and apoptosis; and in vivo, after transplantation into immunodeficient mice with chemically induced diabetes, by examining blood glucose levels, oral glucose tolerance tests and stimulated human C-peptide over a 50-day follow-up period. Our data showed that neither in vitro, nor in vivo human islet function was impaired by FTY720 exposure. Since FTY720 demonstrated no detrimental effects on human islet function in vitro or in vivo, emerging S1PR modulators may prove to be useful adjuncts in clinical islet transplantation through lack of diabetogenicity and potent immunological protection.
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Affiliation(s)
- W Truong
- The Surgical Medical Research Institute, Department of Surgery, Faculty of Medicine, The University of Alberta, Edmonton, Alberta, Canada
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28
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Laychock SG, Sessanna SM, Lin MH, Mastrandrea LD. Sphingosine 1-phosphate affects cytokine-induced apoptosis in rat pancreatic islet beta-cells. Endocrinology 2006; 147:4705-12. [PMID: 16794003 DOI: 10.1210/en.2006-0456] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cytokines mediate pancreatic islet beta-cell apoptosis and necrosis, leading to loss of insulin secretory capacity and type 1 diabetes mellitus. The cytokines, IL-1beta and interferon-gamma, induced terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) staining of rat islet cells within 48 h by about 25-30%, indicative of apoptosis and/or necrosis. Sphingosine 1-phosphate (S1P) at nanomolar concentrations significantly reduced islet cell cytokine-induced TUNEL staining. Similar effects were observed in INS-1 cells. The dihydro analog of S1P also reduced the percentage of TUNEL stained islet and INS-1 cells, whereas the S1P receptor antagonist BML-241 blocked the protective effects. Pertussis toxin did not affect the S1P protective response. In the presence of a phospholipase C antagonist, U73122, there was significant inhibition of the S1P protective effects against apoptosis/necrosis. S1P stimulated INS-1 cell protein kinase C activity. Carbamylcholine chloride acting through muscarinic receptors also inhibited cytokine-induced TUNEL staining in pancreatic islet cells. S1P and/or dihydro-S1P also antagonized cytokine-induced increases in cytochrome c release from mitochondria and caspase-3 activity in INS-1 cells, which are indicative of cell apoptosis vs. necrosis. S1P failed to affect nitric oxide synthase activity after 48 h. Thus, the evidence suggests that S1P acting on S1P receptors coupled to G(q) mediates protective effects on islet beta-cells against cytokine-induced apoptosis.
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Affiliation(s)
- Suzanne G Laychock
- 102 Farber Hall, Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, The University at Buffalo, New York 14214, USA.
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29
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Kowluru A. Novel regulatory roles for protein phosphatase-2A in the islet β cell. Biochem Pharmacol 2005; 69:1681-91. [PMID: 15935144 DOI: 10.1016/j.bcp.2005.03.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Revised: 03/16/2005] [Accepted: 03/16/2005] [Indexed: 10/25/2022]
Abstract
Protein phosphorylation constitutes one of the key signaling steps in physiological insulin secretion. The phosphorylation status of a given protein represents the balance of the activities of protein kinases and phosphatases, which induce the addition and removal of phosphate from that protein, respectively. Although several extant studies were focused on the identification and characterization of protein kinases in islets, relatively little information is available on the localization and regulation of protein phosphatases in beta cells. Emerging evidence implicates protein phosphatase 2A (PP2A) in the phenomenon of insulin secretion. The three principal objectives of this commentary are to: (i) review the existing evidence, which suggests regulation, by glucose and other insulin secretagogues, of PP2A in the beta cell; (ii) discuss the experimental evidence, which implicates PP2A-like enzymes in the dephosphorylation and inactivation of key beta cell phosphoprotein substrates (e.g., Akt and Bcl-2), which may be necessary for beta cell proliferation and survival, culminating in the loss of the beta cell mass; and (iii) highlight potential avenues for future research, including the development of specific pharmacological and therapeutic interventional modalities for the inhibition of specific PP2A-like phosphatases for the prevention of loss of beta cell mass leading to the onset of diabetes.
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Affiliation(s)
- Anjaneyulu Kowluru
- Department of Pharmaceutical Sciences, Wayne State University and Beta Cell Biochemistry Research Laboratory, John D. Dingell VA Medical Center, Detroit, MI 48201, USA.
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Mastrandrea LD, Sessanna SM, Laychock SG. Sphingosine kinase activity and sphingosine-1 phosphate production in rat pancreatic islets and INS-1 cells: response to cytokines. Diabetes 2005; 54:1429-36. [PMID: 15855330 DOI: 10.2337/diabetes.54.5.1429] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Sphingosine-1 phosphate (S1P) is a bioactive sphingolipid with the potential to mobilize Ca2+, to inhibit apoptosis, and to promote mitogenesis. Sphingosine kinase (SPHK) and S1P were characterized in INS-1 insulinoma cells and isolated rat islets of Langerhans. SPHK activity increased in INS-1 cell homogenates treated with interleukin-1beta (IL-1beta) or tumor necrosis factor-alpha (TNF-alpha), and responses were additive. IL-1beta or TNF-alpha increased islet SPHK activity within 15 min to 1 h; activity remained elevated after 8 h. SPHK2 was the predominant active isoform in INS-1 cells; little or no SPHK1 activity was detected. Cytokines increased endogenous S1P biosynthesis in 32P(i)-prelabeled INS-1 cells, and cycloheximide inhibited the response after 8 h, suggesting that protein synthesis mediated the response. There was no [32P]S1P release from cells. Compared with basal values, IL-1beta and TNF-alpha induced increases in SPHK1a mRNA levels relative to 18S ribosomal RNA in INS-1 cells within 1 h; relative SPHK2 mRNA levels were unchanged after cytokine treatment. IL-1beta, but not TNF-alpha, induced relative SPHK1a mRNA expression levels within 1 h in islets, whereas SPHK2 mRNA levels were unchanged. Thus, IL-1beta and TNF-alpha induced an early and sustained increase in SPHK activity in INS-1 cells and isolated islets, suggesting that S1P plays a role in the pathological response of pancreatic beta-cells to cytokines.
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Affiliation(s)
- Lucy D Mastrandrea
- Department of Pharmacology and Toxicology, The State University of New York at Buffalo, Buffalo, NY, USA
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MacDonald MJ, Fahien LA, Brown LJ, Hasan NM, Buss JD, Kendrick MA. Perspective: emerging evidence for signaling roles of mitochondrial anaplerotic products in insulin secretion. Am J Physiol Endocrinol Metab 2005; 288:E1-15. [PMID: 15585595 DOI: 10.1152/ajpendo.00218.2004] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The importance of mitochondrial biosynthesis in stimulus secretion coupling in the insulin-producing beta-cell probably equals that of ATP production. In glucose-induced insulin secretion, the rate of pyruvate carboxylation is very high and correlates more strongly with the glucose concentration the beta-cell is exposed to (and thus with insulin release) than does pyruvate decarboxylation, which produces acetyl-CoA for metabolism in the citric acid cycle to produce ATP. The carboxylation pathway can increase the levels of citric acid cycle intermediates, and this indicates that anaplerosis, the net synthesis of cycle intermediates, is important for insulin secretion. Increased cycle intermediates will alter mitochondrial processes, and, therefore, the synthesized intermediates must be exported from mitochondria to the cytosol (cataplerosis). This further suggests that these intermediates have roles in signaling insulin secretion. Although evidence is quite good that all physiological fuel secretagogues stimulate insulin secretion via anaplerosis, evidence is just emerging about the possible extramitochondrial roles of exported citric acid cycle intermediates. This article speculates on their potential roles as signaling molecules themselves and as exporters of equivalents of NADPH, acetyl-CoA and malonyl-CoA, as well as alpha-ketoglutarate as a substrate for hydroxylases. We also discuss the "succinate mechanism," which hypothesizes that insulin secretagogues produce both NADPH and mevalonate. Finally, we discuss the role of mitochondria in causing oscillations in beta-cell citrate levels. These parallel oscillations in ATP and NAD(P)H. Oscillations in beta-cell plasma membrane electrical potential, ATP/ADP and NAD(P)/NAD(P)H ratios, and glycolytic flux are known to correlate with pulsatile insulin release. Citrate oscillations might synchronize oscillations of individual mitochondria with one another and mitochondrial oscillations with oscillations in glycolysis and, therefore, with flux of pyruvate into mitochondria. Thus citrate oscillations may synchronize mitochondrial ATP production and anaplerosis with other cellular oscillations.
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Affiliation(s)
- Michael J MacDonald
- Childrens Diabetes Center, University of Wisconsin Medical School, Madison, Wisconsin, USA.
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Abstract
The functions of lysophosphatidic acid (LPA) can be broadly divided into two classes: (1) physiological and (2) pathological roles. The role of LPA in embryonic development can be seen as early as oocyte formation. It continues in postnatal homeostasis, through its ability to impart a level of protection from both stress and local injury, by regulating cellular proliferation, apoptosis, and the reorganization of cytoskeletal fibers. LPA may function as a double-edged sword. While it helps maintain homeostasis against stress and insult, it may also augment the development and spread of pathological processes, including cancers.
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Affiliation(s)
- Saubhik Sengupta
- Department of Cancer Biology, The Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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