TY - JOUR
T1 - Taurine supplementation ameliorates glucose homeostasis, prevents insulin and glucagon hypersecretion, and controls β, α, and δ-cell masses in genetic obese mice
AU - Santos-Silva, Junia C.
AU - Ribeiro, Rosane Aparecida
AU - Vettorazzi, Jean F.
AU - Irles, Esperanza
AU - Rickli, Sarah
AU - Borck, Patrícia C.
AU - Porciuncula, Patricia M.
AU - Quesada, Ivan
AU - Nadal, Angel
AU - Boschero, Antonio C.
AU - Carneiro, Everardo M.
N1 - Publisher Copyright:
© 2015 Springer-Verlag.
PY - 2015/8/23
Y1 - 2015/8/23
N2 - Taurine (Tau) regulates β-cell function and glucose homeostasis under normal and diabetic conditions. Here, we assessed the effects of Tau supplementation upon glucose homeostasis and the morphophysiology of endocrine pancreas, in leptin-deficient obese (ob) mice. From weaning until 90-day-old, C57Bl/6 and ob mice received, or not, 5 % Tau in drinking water (C, CT, ob and obT). Obese mice were hyperglycemic, glucose intolerant, insulin resistant, and exhibited higher hepatic glucose output. Tau supplementation did not prevent obesity, but ameliorated glucose homeostasis in obT. Islets from ob mice presented a higher glucose-induced intracellular Ca2+ influx, NAD(P)H production and insulin release. Furthermore, α-cells from ob islets displayed a higher oscillatory Ca2+ profile at low glucose concentrations, in association with glucagon hypersecretion. In Tau-supplemented ob mice, insulin and glucagon secretion was attenuated, while Ca2+ influx tended to be normalized in β-cells and Ca2+ oscillations were increased in α-cells. Tau normalized the inhibitory action of somatostatin (SST) upon insulin release in the obT group. In these islets, expression of the glucagon, GLUT-2 and TRPM5 genes was also restored. Tau also enhanced MafA, Ngn3 and NeuroD mRNA levels in obT islets. Morphometric analysis demonstrated that the hypertrophy of ob islets tends to be normalized by Tau with reductions in islet and β-cell masses, but enhanced δ-cell mass in obT. Our results indicate that Tau improves glucose homeostasis, regulating β-, α-, and δ-cell morphophysiology in ob mice, indicating that Tau may be a potential therapeutic tool for the preservation of endocrine pancreatic function in obesity and diabetes.
AB - Taurine (Tau) regulates β-cell function and glucose homeostasis under normal and diabetic conditions. Here, we assessed the effects of Tau supplementation upon glucose homeostasis and the morphophysiology of endocrine pancreas, in leptin-deficient obese (ob) mice. From weaning until 90-day-old, C57Bl/6 and ob mice received, or not, 5 % Tau in drinking water (C, CT, ob and obT). Obese mice were hyperglycemic, glucose intolerant, insulin resistant, and exhibited higher hepatic glucose output. Tau supplementation did not prevent obesity, but ameliorated glucose homeostasis in obT. Islets from ob mice presented a higher glucose-induced intracellular Ca2+ influx, NAD(P)H production and insulin release. Furthermore, α-cells from ob islets displayed a higher oscillatory Ca2+ profile at low glucose concentrations, in association with glucagon hypersecretion. In Tau-supplemented ob mice, insulin and glucagon secretion was attenuated, while Ca2+ influx tended to be normalized in β-cells and Ca2+ oscillations were increased in α-cells. Tau normalized the inhibitory action of somatostatin (SST) upon insulin release in the obT group. In these islets, expression of the glucagon, GLUT-2 and TRPM5 genes was also restored. Tau also enhanced MafA, Ngn3 and NeuroD mRNA levels in obT islets. Morphometric analysis demonstrated that the hypertrophy of ob islets tends to be normalized by Tau with reductions in islet and β-cell masses, but enhanced δ-cell mass in obT. Our results indicate that Tau improves glucose homeostasis, regulating β-, α-, and δ-cell morphophysiology in ob mice, indicating that Tau may be a potential therapeutic tool for the preservation of endocrine pancreatic function in obesity and diabetes.
KW - Glucagon secretion
KW - Insulin secretion
KW - Obesity
KW - Somatostatin
KW - Taurine supplementation
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U2 - 10.1007/s00726-015-1988-z
DO - 10.1007/s00726-015-1988-z
M3 - Article
C2 - 25940922
AN - SCOPUS:84937725981
SN - 0939-4451
VL - 47
SP - 1533
EP - 1548
JO - Amino Acids
JF - Amino Acids
IS - 8
ER -