Xiaofeng Wang1, Joel Gupta1, Matthew Kerslake1, Gina Rayat2, Spencer D Proctor1, Catherine B Chan1,3. 1. Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada. 2. Alberta Diabetes Institute, Surgical-Medical Research Institute, Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada. 3. Department of Physiology, University of Alberta, Edmonton, AB, Canada.
Abstract
SCOPE: Trans-11 vaccenic acid (VA) is a fatty acid produced by ruminants entering the human food supply through meat and dairy products, which appears not to have the health risks associated with industrially produced trans-fatty acids. In this study, we investigated the effect of VA on insulin secretion in vivo in rats and in vitro in human and rat islets after diabetogenic insult. METHODS AND RESULTS: Hyperglycemic clamp showed that VA dietary supplementation for 8 weeks significantly increased glucose turnover in rats with type 2 diabetes (T2D), accompanied by an elevated plasma C-peptide concentration, indicating improved insulin secretion. The β-cell area and proliferation rate were higher in T2D+VA than T2D group. Isolated islets from T2D+VA rats had higher glucose-stimulated insulin secretion (GSIS) than T2D group. In vitro, VA treatment for 24 and 48 h significantly enhanced GSIS in rat and human islets after diabetogenic challenges. The mRNA expression of G-protein-coupled receptor 40 (GPR40) and regenerating islet-derived 1α (REG-1α) were consistently increased by VA in both rat and human islets. CONCLUSION: These results indicate that VA may improve insulin secretion and growth of islets in T2D, at least partly by altering GPR40 and REG-1α mRNA expression.
SCOPE: Trans-11 vaccenic acid (VA) is a fatty acid produced by ruminants entering the human food supply through meat and dairy products, which appears not to have the health risks associated with industrially produced trans-fatty acids. In this study, we investigated the effect of VA on insulin secretion in vivo in rats and in vitro in human and rat islets after diabetogenic insult. METHODS AND RESULTS: Hyperglycemic clamp showed that VA dietary supplementation for 8 weeks significantly increased glucose turnover in rats with type 2 diabetes (T2D), accompanied by an elevated plasma C-peptide concentration, indicating improved insulin secretion. The β-cell area and proliferation rate were higher in T2D+VA than T2D group. Isolated islets from T2D+VArats had higher glucose-stimulated insulin secretion (GSIS) than T2D group. In vitro, VA treatment for 24 and 48 h significantly enhanced GSIS in rat and human islets after diabetogenic challenges. The mRNA expression of G-protein-coupled receptor 40 (GPR40) and regenerating islet-derived 1α (REG-1α) were consistently increased by VA in both rat and human islets. CONCLUSION: These results indicate that VA may improve insulin secretion and growth of islets in T2D, at least partly by altering GPR40 and REG-1α mRNA expression.
Authors: Farkas Sarnyai; Éva Kereszturi; Kitti Szirmai; Judit Mátyási; Johanna Iman Al-Hag; Tamás Csizmadia; Péter Lőw; Péter Szelényi; Viola Tamási; Kinga Tibori; Veronika Zámbó; Blanka Tóth; Miklós Csala Journal: Int J Mol Sci Date: 2022-06-30 Impact factor: 6.208