Regulation of leptin gene expression by insulin and growth hormone in mouse adipocytes

Abstract

The role of leptin in the control of obesity, insulin resistance and type II diabetes has been reported, however, the regulatory mechanism of leptin in animals affected by hormones is not clearly understood. In this study, the effects of insulin, epinephrine, growth hormone or dexamethasone on the expression of leptin was examined in mouse primary adipocytes. The leptin expression was also studied in the adipose tissue of the mouse treated with insulin or growth hormone (0.3 or 0.6 units/animal). Insulin (100 nM) or dexamethasone (100 nM) stimulated leptin mRNA transcription while epinephrine (100 nM) alleviated its transcription in mouse primary adipocytes. The level of leptin protein in cultured media of adipocytes treated with insulin or dexamethasone was higher than that of the control group but growth hormone or epinephrine treatment had no effect on them. Insulin administration (0.6 units/mouse) enhanced leptin mRNA as well as leptin protein in mouse adipose tissue but growth hormone administration (0.3 or 0.6 units/mouse) had no effect on them. Leptin protein level in sera of mice injected with insulin or growth hormone was not significantly different from that of control group. These results indicate that both insulin and dexamethasone stimulate leptin gene expression and secretion of its product, whereas, growth hormone has no effect on the expression of leptin gene in mouse adipocytes.

Antidiabetic Activity of Zinc Oxide and Silver Nanoparticles on Streptozotocin-Induced Diabetic Rats

“…All experimental animals were housed together for 7 days before the beginning of the experiment. Animals were randomly classified into five groups; the first group served as a control; these animals did not receive any type of treatment, 40 animals received a single intraperitoneal dose of streptozotocin (Sigma-Aldrich, Catalog No S0130 SIGMA, Seelze, Germany) with a dose equals 100 mg/kg [25] for induction of diabetes. They were further classified into four more groups; diabetic groups; they did not receive any type of treatment, diabetic + ZnONPs groups; received oral daily dose of ZnONPs (Sigma-Aldrich, Catalog No.721077, Seelze Germany) of 10 mg/kg for 30 constitutive days, diabetic + SNPs group; received oral daily dose of SNP (Sigma-Aldrich, Catalog No.…”

Leptin in immuno-rheumatological diseases

“…25 Leptin expression in adipocytes is induced by insulin, melanyl-CoA, adenosine triphosphate, glucosamine and short-chain fatty acids, but it is inhibited by cyclic adenosine 5'-monophosphate and long-chain fatty acid. 18,26 Furthermore, the expression of leptin can be directly upregulated by sex hormones and is inhibited by testosterone and increased by ovarian sex steroids. 5 As a result of the effect of sex hormones, leptin levels are higher in women than in men, even when adjusted for BMI, which may be relevant to the influence of sex on the development or frequency of certain diseases.…”

Serum leptin concentrations in adolescents and young adults with growth hormone deficiency

“…Wyniki dotychczas opublikowanych prac dotyczących wpływu hormonu wzrostu na sekrecję leptyny są rozbieżne [31][32][33]. W badaniach in vivo przeprowadzonych na różnych gatunkach zwierząt obserwowano zarówno brak wpływu GH na ekspresję leptyny w adipocytach [33], jak i jego działa-nie pobudzające [31] lub hamujące [32].…”

“…W badaniach in vivo przeprowadzonych na różnych gatunkach zwierząt obserwowano zarówno brak wpływu GH na ekspresję leptyny w adipocytach [33], jak i jego działa-nie pobudzające [31] lub hamujące [32]. Również doniesienia dotyczące wpływu niedoboru GH na stężenia LEP u ludzi nie są spójne [33][34][35][36][37][38][39][40][41]. Brakuje prac dotyczących zachowania się stężeń leptyny w grupie młodzieży i młodych dorosłych w tzw.…”