1
|
Ghiasi SM, Hansen JB, Christensen DP, Tyrberg B, Mandrup-Poulsen T. The Connexin 43 Regulator Rotigaptide Reduces Cytokine-Induced Cell Death in Human Islets. Int J Mol Sci 2020; 21:E4311. [PMID: 32560352 DOI: 10.3390/ijms21124311] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/11/2020] [Accepted: 06/15/2020] [Indexed: 01/23/2023] Open
Abstract
Background: Intercellular communication mediated by cationic fluxes through the Connexin family of gap junctions regulates glucose-stimulated insulin secretion and beta cell defense against inflammatory stress. Rotigaptide (RG, ZP123) is a peptide analog that increases intercellular conductance in cardiac muscle cells by the prevention of dephosphorylation and thereby uncoupling of Connexin-43 (Cx43), possibly via action on unidentified protein phosphatases. For this reason, it is being studied in human arrhythmias. It is unknown if RG protects islet cell function and viability against inflammatory or metabolic stress, a question of considerable translational interest for the treatment of diabetes. Methods: Apoptosis was measured in human islets shown to express Cx43, treated with RG or the control peptide ZP119 and exposed to glucolipotoxicity or IL-1β + IFNɣ. INS-1 cells shown to lack Cx43 were used to examine if RG protected human islet cells via Cx43 coupling. To study the mechanisms of action of Cx43-independent effects of RG, NO, IkBα degradation, mitochondrial activity, ROS, and insulin mRNA levels were determined. Results: RG reduced cytokine-induced apoptosis ~40% in human islets. In Cx43-deficient INS-1 cells, this protective effect was markedly blunted as expected, but unexpectedly, RG still modestly reduced apoptosis, and improved mitochondrial function, insulin-2 gene levels, and accumulated insulin release. RG reduced NO production in Cx43-deficient INS-1 cells associated with reduced iNOS expression, suggesting that RG blunts cytokine-induced NF-κB signaling in insulin-producing cells in a Cx43-independent manner. Conclusion: RG reduces cytokine-induced cell death in human islets. The protective action in Cx43-deficient INS-1 cells suggests a novel inhibitory mechanism of action of RG on NF-κB signaling.
Collapse
|
2
|
Seferovic MD, Beamish CA, Mosser RE, Townsend SE, Pappan K, Poitout V, Aagaard KM, Gannon M. Increases in bioactive lipids accompany early metabolic changes associated with β-cell expansion in response to short-term high-fat diet. Am J Physiol Endocrinol Metab 2018; 315:E1251-E1263. [PMID: 30106624 PMCID: PMC6336958 DOI: 10.1152/ajpendo.00001.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Pancreatic β-cell expansion is a highly regulated metabolic adaptation to increased somatic demands, including obesity and pregnancy; adult β cells otherwise rarely proliferate. We previously showed that high-fat diet (HFD) feeding induces mouse β-cell proliferation in less than 1 wk in the absence of insulin resistance. Here we metabolically profiled tissues from a short-term HFD β-cell expansion mouse model to identify pathways and metabolite changes associated with β-cell proliferation. Mice fed HFD vs. chow diet (CD) showed a 14.3% increase in body weight after 7 days; β-cell proliferation increased 1.75-fold without insulin resistance. Plasma from 1-wk HFD-fed mice induced β-cell proliferation ex vivo. The plasma, as well as liver, skeletal muscle, and bone, were assessed by LC and GC mass-spectrometry for global metabolite changes. Of the 1,283 metabolites detected, 159 showed significant changes [false discovery rate (FDR) < 0.1]. The majority of changes were in liver and muscle. Pathway enrichment analysis revealed key metabolic changes in steroid synthesis and lipid metabolism, including free fatty acids and other bioactive lipids. Other important enrichments included changes in the citric acid cycle and 1-carbon metabolism pathways implicated in DNA methylation. Although the minority of changes were observed in bone and plasma (<20), increased p-cresol sulfate was increased >4 fold in plasma (the largest increase in all tissues), and pantothenate (vitamin B5) decreased >2-fold. The results suggest that HFD-mediated β-cell expansion is associated with complex, global metabolite changes. The finding could be a significant insight into Type 2 diabetes pathogenesis and potential novel drug targets.
Collapse
Affiliation(s)
- Maxim D Seferovic
- Department of Obstetrics and Gynecology, Baylor College of Medicine , Houston, Texas
| | - Christine A Beamish
- Department of Surgery, Houston Methodist Hospital Research Institute , Houston, Texas
| | - Rockann E Mosser
- Department of Veterans Affairs , Nashville, Tennessee
- Department of Medicine, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Shannon E Townsend
- Department of Molecular Physiology and Biophysics, Vanderbilt University , Nashville, Tennessee
| | | | | | - Kjersti M Aagaard
- Department of Obstetrics and Gynecology, Baylor College of Medicine , Houston, Texas
| | - Maureen Gannon
- Department of Veterans Affairs , Nashville, Tennessee
- Department of Medicine, Vanderbilt University Medical Center , Nashville, Tennessee
- Department of Molecular Physiology and Biophysics, Vanderbilt University , Nashville, Tennessee
| |
Collapse
|
3
|
Ghiasi SM, Krogh N, Tyrberg B, Mandrup-Poulsen T. The No-Go and Nonsense-Mediated RNA Decay Pathways Are Regulated by Inflammatory Cytokines in Insulin-Producing Cells and Human Islets and Determine β-Cell Insulin Biosynthesis and Survival. Diabetes 2018; 67:2019-2037. [PMID: 30065031 DOI: 10.2337/db18-0073] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 07/23/2018] [Indexed: 11/13/2022]
Abstract
Stress-related changes in β-cell mRNA levels result from a balance between gene transcription and mRNA decay. The regulation of RNA decay pathways has not been investigated in pancreatic β-cells. We found that no-go and nonsense-mediated RNA decay pathway components (RDPCs) and exoribonuclease complexes were expressed in INS-1 cells and human islets. Pelo, Dcp2, Dis3L2, Upf2, and Smg1/5/6/7 were upregulated by inflammatory cytokines in INS-1 cells under conditions where central β-cell mRNAs were downregulated. These changes in RDPC mRNA or corresponding protein levels were largely confirmed in INS-1 cells and rat/human islets. Cytokine-induced upregulation of Pelo, Xrn1, Dis3L2, Upf2, and Smg1/6 was reduced by inducible nitric oxide synthase inhibition, as were endoplasmic reticulum (ER) stress, inhibition of Ins1/2 mRNA, and accumulated insulin secretion. Reactive oxygen species inhibition or iron chelation did not affect RDPC expression. Pelo or Xrn1 knockdown (KD) aggravated, whereas Smg6 KD ameliorated, cytokine-induced INS-1 cell death without affecting ER stress; both increased insulin biosynthesis and medium accumulation but not glucose-stimulated insulin secretion in cytokine-exposed INS-1 cells. In conclusion, RDPCs are regulated by inflammatory stress in β-cells. RDPC KD improved insulin biosynthesis, likely by preventing Ins1/2 mRNA clearance. Pelo/Xrn1 KD aggravated, but Smg6 KD ameliorated, cytokine-mediated β-cell death, possibly through prevention of proapoptotic and antiapoptotic mRNA degradation, respectively.
Collapse
Affiliation(s)
- Seyed Mojtaba Ghiasi
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai Krogh
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Björn Tyrberg
- Translational Science; Cardiovascular, Renal and Metabolism; and IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | | |
Collapse
|
4
|
Scicali R, Di Pino A, Ferrara V, Urbano F, Piro S, Rabuazzo AM, Purrello F. New treatment options for lipid-lowering therapy in subjects with type 2 diabetes. Acta Diabetol 2018; 55:209-218. [PMID: 29260404 DOI: 10.1007/s00592-017-1089-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 12/11/2017] [Indexed: 12/15/2022]
Abstract
Dyslipidemias represent a variety of quantitative and/or qualitative lipoprotein abnormalities. According to etiology, we distinguish primary dyslipidemias with strictly genetic background and secondary ones with their origin in other disease or pathological states. Diabetic dyslipidemia is a type of secondary dyslipidemia and plays an important role in determining the cardiovascular risk of subjects with type 2 diabetes. In these patients, insulin resistance is responsible for overproduction and secretion of atherogenic very low density lipoprotein. In addition, insulin resistance promotes the production of small dense low-density lipoprotein (LDL) and reduces high-density lipoprotein (HDL) production. Cardiovascular disease remains a leading cause of morbidity and mortality in diabetic patients. Previous results support the role for small, dense LDL particles in the etiology of atherosclerosis and their association with coronary artery disease. Moreover, lowering LDL cholesterol reduces the risk of cardiovascular death. Therefore, the European guidelines for the management of dyslipidemias recommend an LDL cholesterol goal < 100 mg/dL in diabetic subjects without cardiovascular events. Moreover, if triglycerides (TG) are elevated (> 400 mg/dL), they recommend a non-HDL cholesterol goal < 130 mg/dL in diabetic individuals without cardiovascular events. Statins are the first line of LDL-lowering therapy in diabetic patients and combined therapy with ezetimibe and statins could be useful in very high cardiovascular risk diabetic subjects. Furthermore, the effect of a fibrate as an add-on treatment to a statin could improve the lipid profile in diabetic individuals with high TG and low HDL cholesterol. Regarding new therapies, recent data from phase III trials show that proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors considerably decrease LDL cholesterol. Thus, they may be useful in diabetic patients with concomitant diseases such as familial dyslipidemia, recurrent cardiovascular events, and elevated LDL cholesterol after second drug administration in addition to maximal statin dose or statin intolerance.
Collapse
Affiliation(s)
- Roberto Scicali
- Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Antonino Di Pino
- Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Viviana Ferrara
- Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Francesca Urbano
- Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Salvatore Piro
- Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Agata Maria Rabuazzo
- Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Francesco Purrello
- Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy.
- Department of Clinical and Experimental Medicine, Internal Medicine, Garibaldi Hospital, University of Catania, Via Palermo, 636, 95122, Catania, Italy.
| |
Collapse
|
5
|
Urbano F, Bugliani M, Filippello A, Scamporrino A, Di Mauro S, Di Pino A, Scicali R, Noto D, Rabuazzo AM, Averna M, Marchetti P, Purrello F, Piro S. Atorvastatin but Not Pravastatin Impairs Mitochondrial Function in Human Pancreatic Islets and Rat β-Cells. Direct Effect of Oxidative Stress. Sci Rep 2017; 7:11863. [PMID: 28928397 DOI: 10.1038/s41598-017-11070-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 08/14/2017] [Indexed: 12/14/2022] Open
Abstract
Statins are a class of drugs widely prescribed as frontline therapy for lowering plasma LDL-cholesterol in cardiovascular risk prevention. Several clinical reports have recently suggested an increased risk of type 2 diabetes associated with chronic use of these drugs. The pathophysiology of this effect remains to be fully elucidated but impaired β-cell function constitutes a potential mechanism. The aim of this study was to explore the effect of a chronic treatment with lipophilic and hydrophilic statins on β-cell function, using human pancreatic islets and rat insulin-secreting INS-1 cells; we particularly focused on the role of mitochondria and oxidative stress. The present study demonstrates, for the first time, that atorvastatin (lipophilic) but not pravastatin (hydrophilic) affected insulin release and mitochondrial metabolism due to the suppression of antioxidant defense system and induction of ROS production in pancreatic β-cell models. Mevalonate addition and treatment with a specific antioxidant (N-AcetylCysteine) effectively reversed the observed defects. These data demonstrate that mitochondrial oxidative stress is a key element in the pathogenesis of statin-related diabetes and may have clinical relevance to design strategies for prevention or reduction of statin induced β-cell dysfunction and diabetes in patients treated with lipophilic statins.
Collapse
|
6
|
Salunkhe VA, Mollet IG, Ofori JK, Malm HA, Esguerra JLS, Reinbothe TM, Stenkula KG, Wendt A, Eliasson L, Vikman J. Dual Effect of Rosuvastatin on Glucose Homeostasis Through Improved Insulin Sensitivity and Reduced Insulin Secretion. EBioMedicine 2016; 10:185-94. [PMID: 27453321 PMCID: PMC5006666 DOI: 10.1016/j.ebiom.2016.07.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/24/2016] [Accepted: 07/07/2016] [Indexed: 11/16/2022] Open
Abstract
Statins are beneficial in the treatment of cardiovascular disease (CVD), but these lipid-lowering drugs are associated with increased incidence of new on-set diabetes. The cellular mechanisms behind the development of diabetes by statins are elusive. Here we have treated mice on normal diet (ND) and high fat diet (HFD) with rosuvastatin. Under ND rosuvastatin lowered blood glucose through improved insulin sensitivity and increased glucose uptake in adipose tissue. In vitro rosuvastatin reduced insulin secretion and insulin content in islets. In the beta cell Ca2 + signaling was impaired and the density of granules at the plasma membrane was increased by rosuvastatin treatment. HFD mice developed insulin resistance and increased insulin secretion prior to administration of rosuvastatin. Treatment with rosuvastatin decreased the compensatory insulin secretion and increased glucose uptake. In conclusion, our data shows dual effects on glucose homeostasis by rosuvastatin where insulin sensitivity is improved, but beta cell function is impaired. Rosuvastatin lowered blood glucose in vivo most likely due to improved glucose uptake. Rosuvastatin reduced insulin content and impaired Ca2 + signaling in beta cells leading to reduced insulin secretion. Dual effects of rosuvastatin in HFD mice though decreased compensatory insulin secretion and increased glucose uptake.
Statins are a group of drugs used to lower blood cholesterol in individuals with a risk of developing cardiovascular disease. It has been shown in several studies that statins increase the risk of developing type 2 diabetes. This increased risk has not yet been explained. We have investigated the effect of rosuvastatin on blood glucose regulation in mice. We found that rosuvastatin has a beneficial effect on glucose uptake in muscles which results in lowered blood glucose. However, in the insulin producing beta cells rosuvastatin altered normal cell function something that might increase the risk of developing type 2 diabetes.
Collapse
Affiliation(s)
- Vishal A Salunkhe
- Unit of Islet Cell Exocytosis, Dept Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University CRC 91-11, SUS Malmö, Jan Waldenströms gata 35, 205 02 Malmö, Sweden
| | - Inês G Mollet
- Unit of Islet Cell Exocytosis, Dept Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University CRC 91-11, SUS Malmö, Jan Waldenströms gata 35, 205 02 Malmö, Sweden
| | - Jones K Ofori
- Unit of Islet Cell Exocytosis, Dept Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University CRC 91-11, SUS Malmö, Jan Waldenströms gata 35, 205 02 Malmö, Sweden
| | - Helena A Malm
- Unit of Islet Cell Exocytosis, Dept Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University CRC 91-11, SUS Malmö, Jan Waldenströms gata 35, 205 02 Malmö, Sweden
| | - Jonathan L S Esguerra
- Unit of Islet Cell Exocytosis, Dept Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University CRC 91-11, SUS Malmö, Jan Waldenströms gata 35, 205 02 Malmö, Sweden
| | - Thomas M Reinbothe
- Inst. Neuroscience and Physiology, Dept of Physiology, University of Gothenburg, Medicinaregatan 11-13, Box 432, 405 30 Gothenburg, Sweden
| | - Karin G Stenkula
- Unit of Glucose Transport and Protein Trafficking, Dept of Experimental Medical Sciences, Lund University Diabetes Centre, Lund University BMC-C11, Sölvegatan 21, 222 84 Lund, Sweden
| | - Anna Wendt
- Unit of Islet Cell Exocytosis, Dept Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University CRC 91-11, SUS Malmö, Jan Waldenströms gata 35, 205 02 Malmö, Sweden
| | - Lena Eliasson
- Unit of Islet Cell Exocytosis, Dept Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University CRC 91-11, SUS Malmö, Jan Waldenströms gata 35, 205 02 Malmö, Sweden.
| | - Jenny Vikman
- Unit of Diabetes and Endocrinology, Dept Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University CRC 60-13, SUS Malmö, Jan Waldenströms gata 35, 205 02 Malmö, Sweden.
| |
Collapse
|
7
|
Salunkhe VA, Elvstam O, Eliasson L, Wendt A. Rosuvastatin Treatment Affects Both Basal and Glucose-Induced Insulin Secretion in INS-1 832/13 Cells. PLoS One 2016; 11:e0151592. [PMID: 26986474 PMCID: PMC4795644 DOI: 10.1371/journal.pone.0151592] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/01/2016] [Indexed: 11/18/2022] Open
Abstract
Rosuvastatin is a member of the statin family. Like the other statins it is prescribed to lower cholesterol levels and thereby reduce the risk of cardiovascular events. Rosuvastatin lowers the cholesterol levels by inhibiting the key enzyme 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-CoA reductase) in the cholesterol producing mevalonate pathway. It has been recognized that apart from their beneficial lipid lowering effects, statins also exhibit diabetogenic properties. The molecular mechanisms behind these remain unresolved. To investigate the effects of rosuvastatin on insulin secretion, we treated INS-1 832/13 cells with varying doses (20 nM to 20 μM) of rosuvastatin for 48 h. At concentrations of 2 μM and above basal insulin secretion was significantly increased. Using diazoxide we could determine that rosuvastatin did not increase basal insulin secretion by corrupting the KATP channels. Glucose-induced insulin secretion on the other hand seemed to be affected differently at different rosuvastatin concentrations. Rosuvastatin treatment (20 μM) for 24–48 h inhibited voltage-gated Ca2+ channels, which lead to reduced depolarization-induced exocytosis of insulin-containing granules. At lower concentrations of rosuvastatin (≤ 2 μM) the stimulus-secretion coupling pathway was intact downstream of the KATP channels as assessed by the patch clamp technique. However, a reduction in glucose-induced insulin secretion could be observed with rosuvastatin concentrations as low as 200 nM. The inhibitory effects of rosuvastatin on glucose-induced insulin secretion could be reversed with mevalonate, but not squalene, indicating that rosuvastatin affects insulin secretion through its effects on the mevalonate pathway, but not through the reduction of cholesterol biosynthesis. Taken together, these data suggest that rosuvastatin has the potential to increase basal insulin secretion and reduce glucose-induced insulin secretion. The latter is possibly an unavoidable side effect of rosuvastatin treatment as it occurs through the same mechanisms as the lipid-lowering effects of the drug.
Collapse
Affiliation(s)
- Vishal A. Salunkhe
- Unit of Islet Cell Exocytosis, Lund University Diabetes Centre, Dept. Clinical Sciences in Malmö, Lund University, Clinical Research Centre, SUS Malmö, Malmö, Sweden
- * E-mail:
| | - Olof Elvstam
- Unit of Islet Cell Exocytosis, Lund University Diabetes Centre, Dept. Clinical Sciences in Malmö, Lund University, Clinical Research Centre, SUS Malmö, Malmö, Sweden
| | - Lena Eliasson
- Unit of Islet Cell Exocytosis, Lund University Diabetes Centre, Dept. Clinical Sciences in Malmö, Lund University, Clinical Research Centre, SUS Malmö, Malmö, Sweden
| | - Anna Wendt
- Unit of Islet Cell Exocytosis, Lund University Diabetes Centre, Dept. Clinical Sciences in Malmö, Lund University, Clinical Research Centre, SUS Malmö, Malmö, Sweden
| |
Collapse
|
8
|
|