Effect of insulin on transcription of lipogenic and lipolytic-related genes and lipid metabolism in primary porcine adipocytes

2006 ◽  
Vol 3 (2) ◽  
pp. 135-140
Author(s):  
Lu Jian-Xiong ◽  
Chen Fen-Fen ◽  
Yang Gong-She
Keyword(s):  
Fatty Acid Synthase ◽  
Lipolytic Activity ◽  
Binding Protein ◽  
Regulatory Element ◽  
Mrna Level ◽  
Hormone Sensitive Lipase ◽  
Mrna Levels ◽  
Tissue Samples ◽  
Element Binding Protein ◽  
High Insulin

AbstractPrimary adipocytes from subcutaneous adipose tissue samples obtained from 7-day-old Yorkshire×Landrace crossbreed piglets were exposed to 0–400 nmol/l of insulin for 48 h. The accumulated triglyceride was measured through Oil Red O staining and the cumulative glycerol released was determined to assess lipolytic activity in adipocytes. Transcription levels of sterol regulatory element binding protein (SREBP)-1c, carbohydrate response element binding protein (ChREBP), acetyl-CoA carboxylase 1 (ACC1), fatty acid synthase (FAS), and hormone-sensitive lipase (HSL) were assessed using reverse transcriptase-polymerase chain reaction (RT-PCR). The results showed that ChREBP and ACC1 mRNA levels were not influenced by insulin alone under low glucose (5 nmol/l). FAS mRNA level was markedly stimulated by all doses of insulin except 200 nmol/l, and SREBP-1c mRNA level increased with 100–300 nmol/l insulin. High insulin doses (300 and 400 nmol/l) increased the HSL mRNA level as well as lipolytic activity.

scholarly journals GH and insulin affect fatty acid synthase activity in isolated porcine adipocytes in culture without any modifications of sterol regulatory element binding protein-1 expression

2004 ◽  
Vol 181 (2) ◽  
pp. 271-280 ◽  
Author(s):  
I Louveau ◽  
F Gondret
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Binding Protein ◽  
Regulatory Element ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Tissue Samples ◽  
Element Binding Protein ◽  
Sterol Regulatory Element ◽  
Porcine Adipocytes

The ability of GH to decrease fatness and insulin-regulated events such as lipogenic enzyme activities is well known in pigs. Nevertheless, the precise mechanism underlying these actions has not been elucidated yet. Expression of the transcription factor sterol regulatory element binding protein (SREBP)-1 has been reported as a key mediator of insulin action in rat hepatocytes and adipose cell lines. The present study aimed to determine whether the regulation of lipogenesis by GH and/or insulin in porcine adipocytes also involved SREBP-1. Isolated adipocytes, obtained from perirenal or s.c. adipose tissue samples of female pigs (51+/-0.4 kg; n=17), were cultured in serum-free medium in the absence or presence of these hormones for up to 4 days. Glucose incorporation and fatty acid synthase activity were increased by insulin in a dose-dependent manner in adipocytes of both sites. The increase was maximal at 1.7 and 17 nM in s.c. and perirenal adipocytes respectively, suggesting inter-depot differences in the regulation of lipogenesis by insulin. These insulin-stimulated events were decreased by GH (1 nM). No change in SREBP-1 mRNA levels was observed in response to GH and/or insulin. Taken together, these data indicate that the regulation of lipogenesis by insulin and GH appears to not involve changes in SREBP-1 mRNA levels in porcine adipocytes.

Insulin induced lipogenesis and enhanced mRNA level of sterol regulatory element binding protein-1c in primary porcine adipocyte

2008 ◽  
Vol 88 (3) ◽  
pp. 419-424 ◽  
Author(s):  
Y. Li ◽  
G. S. Yang
Keyword(s):  
Binding Protein ◽  
Regulatory Element ◽  
Mrna Level ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Significant Difference ◽  
Element Binding Protein ◽  
Sterol Regulatory Element ◽  
Porcine Adipocytes ◽  
Dose Dependent

Little is known about the development and metabolism of the pig adipocyte, and even less is known about regulation of lipogenesis in the pig adipocyte. The objective of this study was to test the effects of insulin on the morphology of cells, the content of triacylglycerols (TG), the activity of fatty acid synthase (FAS) and the mRNA level of sterol regulatory element binding protein-1c (SREBP-1c) in porcine adipocytes in vitro. Morphologically, larger lipid droplets appeared in the presence of insulin for 48 h. Insulin-induced lipogenesis of primary porcine adipocytes was correlated with the TG content and FAS activity. There was a significant difference in the TG content and FAS activity between the insulin-treated cells and the control cells (P < 0.05); insulin increased the content of TG and FAS activity in a dose-dependent manner and the maximum activity occurred at 150 nmol L-1. The TG content and FAS activity were increased in a dose-dependent manner and maximal values were obtained when adipocytes were incubated with 150 nmol L-1 insulin. The mRNA levels of SREBP-1c were also increased by insulin. In summary, lipogenesis of porcine adipocyte could be induced by insulin in a dose-dependent manner and the induced hypertrophy of porcine adipocytes partially due to the increase of TG content, FAS activity and SREBP-1c mRNA level. Key words: Lipogenesis, porcine, adipocyte, insulin, SREBP-1c

scholarly journals Central Leptin Regulates Total Ceramide Content and Sterol Regulatory Element Binding Protein-1C Proteolytic Maturation in Rat White Adipose Tissue

Endocrinology ◽  
2008 ◽  
Vol 150 (1) ◽  
pp. 169-178 ◽  
Author(s):  
Elena Bonzón-Kulichenko ◽  
Dominik Schwudke ◽  
Nilda Gallardo ◽  
Eduardo Moltó ◽  
Teresa Fernández-Agulló ◽  
...  
Keyword(s):  
Nervous System ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
White Adipose Tissue ◽  
Binding Protein ◽  
Regulatory Element ◽  
Mrna Levels ◽  
Element Binding Protein ◽  
Ceramide Content ◽  
Sterol Regulatory Element

Obesity and type 2 diabetes are associated with insulin and leptin resistance, and increased ceramide contents in target tissues. Because the adipose tissue has become a central focus in these diseases, and leptin-induced increases in insulin sensitivity may be related to effects of leptin on lipid metabolism, we investigated herein whether central leptin was able to regulate total ceramide levels and the expression of enzymes involved in ceramide metabolism in rat white adipose tissue (WAT). After 7 d central leptin treatment, the total content of ceramides was analyzed by quantitative shotgun lipidomics mass spectrometry. The effects of leptin on the expression of several enzymes of the sphingolipid metabolism, sterol regulatory element binding protein (SREBP)-1c, and insulin-induced gene 1 (INSIG-1) in this tissue were studied. Total ceramide levels were also determined after surgical WAT denervation. Central leptin infusion significantly decreased both total ceramide content and the long-chain fatty acid ceramide species in WAT. Concomitant with these results, leptin decreased the mRNA levels of enzymes involved in de novo ceramide synthesis (SPT-1, LASS2, LASS4) and ceramide production from sphingomyelin (SMPD-1/2). The mRNA levels of enzymes of ceramide degradation (Asah1/2) and utilization (sphingomyelin synthase, ceramide kinase, glycosyl-ceramide synthase, GM3 synthase) were also down-regulated. Ceramide-lowering effects of central leptin were prevented by local autonomic nervous system denervation of WAT. Finally, central leptin treatment markedly increased INSIG-1 mRNA expression and impaired SREBP-1c activation in epididymal WAT. These observations indicate that in vivo central leptin, acting through the autonomic nervous system, regulates total ceramide levels and SREBP-1c proteolytic maturation in WAT, probably contributing to improve the overall insulin sensitivity. Central leptin decreases total ceramide levels and prevents sterol regulatory element binding protein (SREBP-1C) proteolytic maturation in white adipose tissue, and probably, in this way, contributes to improve the overall insulin sensitivity.

scholarly journals Dietary zinc addition influenced zinc and lipid deposition in the fore- and mid-intestine of juvenile yellow catfishPelteobagrus fulvidraco

2017 ◽  
Vol 118 (8) ◽  
pp. 570-579 ◽  
Author(s):  
Guang-Hui Chen ◽  
Christer Hogstrand ◽  
Zhi Luo ◽  
Dian-Guang Zhang ◽  
Shi-Cheng Ling ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Fatty Acid Synthase ◽  
Hormone Sensitive Lipase ◽  
Pelteobagrus Fulvidraco ◽  
Lipid Deposition ◽  
Mrna Levels ◽  
Yellow Catfish ◽  
Element Binding Protein ◽  
Zinc Addition ◽  
Glucose 6 Phosphate Dehydrogenase

AbstractThe present study explored the mechanisms of dietary Zn influencing Zn and lipid deposition in the fore- and mid- intestine in yellow catfishPelteobagrus fulvidraco, and investigated whether the mechanism was intestinal-region dependent. For this purpose, yellow catfish were fed three diets containing Zn levels of 8·83, 19·20 and 146·65 mg Zn/kg, respectively. Growth performance, intestinal TAG and Zn contents as well as activities and mRNA expression of enzymes and genes involved in Zn transport and lipid metabolism in the fore- and mid-intestine were analysed. Dietary Zn increased Zn accumulation as well as activities of Cu-, Zn-superoxide dismutase and ATPase in the fore- and mid-intestine. In the fore-intestine, dietary Zn up-regulated mRNA levels of ZnT1, ZnT5, ZnT7, metallothionein (MT) and metal response element-binding transcription factor-1 (MTF-1), but down-regulated mRNA levels of ZIP4 and ZIP5. In the mid-intestine, dietary Zn up-regulated mRNA levels of ZnT1, ZnT5, ZnT7, MT and MTF-1, but down-regulated mRNA levels of ZIP4 and ZIP5. Dietary Zn reduced TAG content, down-regulated activities of 6-phosphogluconate dehydrogenase (6PGD), glucose-6-phosphate dehydrogenase (G6PD), malic enzyme (ME) and fatty acid synthase (FAS) activities, and reduced mRNA levels of 6PGD, G6PD, FAS, PPARγand sterol-regulator element-binding protein (SREBP-1), but up-regulated mRNA levels of carnitine palmitoyltransferase IA, hormone-sensitive lipase (HSLa), adipose TAG lipase (ATGL) and PPARαin the fore-intestine. In the mid-intestine, dietary Zn reduced TAG content, activities of G6PD, ME, isocitrate dehydrogenase and FAS, down-regulated mRNA levels of 6PGD, G6PD, FAS, acetyl-CoA carboxylase a, PPARγand SREBP-1, but up-regulated mRNA expression of HSLa, ATGL and PPARγ. The reduction in TAG content following Zn addition was attributable to reduced lipogenesis and increased lipolysis, and similar regulatory mechanisms were observed between the fore- and mid-intestine.

Regulation of fatty acid synthase expression in breast cancer by sterol regulatory element binding protein-1c

2003 ◽  
Vol 282 (2) ◽  
pp. 132-137 ◽  
Author(s):  
Y.u-A.n Yang ◽  
Patrice J. Morin ◽  
Wan Fang Han ◽  
Tinghua Chen ◽  
Daniel M. Bornman ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Binding Protein ◽  
Regulatory Element ◽  
Element Binding Protein ◽  
Sterol Regulatory Element

scholarly journals A simple promoter containing two Sp1 sites controls the expression of sterol-regulatory-element-binding protein 1a (SREBP-1a)

2005 ◽  
Vol 386 (1) ◽  
pp. 161-168 ◽  
Author(s):  
Chengkang ZHANG ◽  
Dong-Ju SHIN ◽  
Timothy F. OSBORNE
Keyword(s):  
Transcriptional Activation ◽  
Binding Protein ◽  
Regulatory Element ◽  
Animal Experiments ◽  
Proximal Region ◽  
Mrna Levels ◽  
Relative Level ◽  
Transcriptional Activation Domain ◽  
Element Binding Protein ◽  
Sterol Regulatory Element

The mammalian gene for SREBP-1 (sterol-regulatory-element-binding protein 1) contains two promoters that control the production of two proteins, SREBP-1a and -1c, and each contains a unique N-terminal transcriptional activation domain, but they are otherwise identical. The relative level of each mRNA varies from tissue to tissue and they respond differently to regulatory stimuli. SREBP-1c is more abundantly expressed in liver, where its level is also regulated by insulin and liver X receptor activators, and it is also autoregulated by SREBPs. In contrast, SREBP-1a mRNA levels are relatively low and constant in different tissues and few studies have specifically analysed its pattern of expression and regulation. In the present study, we show that the promoter for SREBP-1a is contained in a very small promoter-proximal region containing two Sp1 sites. The small and relatively simple structure for its promoter provides an explanation for the low level of SREBP-1a expression. Additionally, since Sp1 has been implicated in the modest regulation of several genes by insulin, its involvement in the expression of the SREBP-1a promoter provides an explanation for the modest insulin regulation observed in animal experiments.

Effects of gender and GH secretory pattern on sterol regulatory element-binding protein-1c and its target genes in rat liver

2004 ◽  
Vol 287 (6) ◽  
pp. E1039-E1048 ◽  
Author(s):  
Caroline Améen ◽  
Daniel Lindén ◽  
Britt-Mari Larsson ◽  
Agneta Mode ◽  
Agneta Holmäng ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Continuous Infusion ◽  
Target Genes ◽  
Binding Protein ◽  
Regulatory Element ◽  
Female Rats ◽  
Mrna Levels ◽  
Element Binding Protein ◽  
Sterol Regulatory Element ◽  
Secretory Pattern

We investigated whether the sexually dimorphic secretory pattern of growth hormone (GH) in the rat regulates hepatic gene expression of sterol regulatory element-binding protein-1c (SREBP-1c) and its target genes. SREBP-1c, fatty acid synthase (FAS), and glycerol-3-phosphate acyltransferase (GPAT) mRNA were more abundant in female than in male livers, whereas acetyl-CoA carboxylase-1 (ACC1) and stearoyl-CoA desaturase-1 (SCD-1) were similarly expressed in both sexes. Hypophysectomized female rats were given GH as a continuous infusion or as two daily injections for 7 days to mimic the female- and male-specific GH secretory patterns, respectively. The female pattern of GH administration increased the expression of SREBP-1c, ACC1, FAS, SCD-1, and GPAT mRNA, whereas the male pattern of GH administration increased only SCD-1 mRNA. FAS and SCD-1 protein levels were regulated in a similar manner by GH. Incubation of primary rat hepatocytes with GH increased SCD-1 mRNA levels and decreased FAS and GPAT mRNA levels but had no effect on SREBP-1c mRNA. GH decreased hepatic liver X receptor-α (LXRα) mRNA levels both in vivo and in vitro. Feminization of the GH plasma pattern in male rats by administration of GH as a continuous infusion decreased insulin sensitivity and increased expression of FAS and GPAT mRNA but had no effect on SREBP-1c, ACC1, SCD-1, or LXRα mRNA. In conclusion, FAS and GPAT are specifically upregulated by the female secretory pattern of GH. This regulation is not a direct effect of GH on hepatocytes and does not involve changed expression of SREBP-1c or LXRα mRNA but is associated with decreased insulin sensitivity.

scholarly journals Ergosterol Peroxide from the Medicinal Mushroom Ganoderma lucidum Inhibits Differentiation and Lipid Accumulation of 3T3-L1 Adipocytes

2020 ◽  
Vol 21 (2) ◽  
pp. 460 ◽  
Author(s):  
Yong-Un Jeong ◽  
Young-Jin Park
Keyword(s):  
Transcription Factors ◽  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Metabolic Diseases ◽  
Binding Protein ◽  
Regulatory Element ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
Medicinal Mushrooms ◽  
Ergosterol Peroxide

Ergosterol peroxide is a natural compound of the steroid family found in many fungi, and it possesses antioxidant, anti-inflammatory, anticancer and antiviral activities. The anti-obesity activity of several edible and medicinal mushrooms has been reported, but the effect of mushroom-derived ergosterol peroxide on obesity has not been studied. Therefore, we analyzed the effect of ergosterol peroxide on the inhibition of triglyceride synthesis at protein and mRNA levels and differentiation of 3T3-L1 adipocytes. Ergosterol peroxide inhibited lipid droplet synthesis of differentiated 3T3-L1 cells, expression of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAT/enhancer-binding protein alpha (C/EBPα), the major transcription factors of differentiation, and also the expression of sterol regulatory element-binding protein-1c (SREBP-1c), which promotes the activity of PPARγ, resulting in inhibition of differentiation. It further inhibited the expression of fatty acid synthase (FAS), fatty acid translocase (FAT), and acetyl-coenzyme A carboxylase (ACC), which are lipogenic factors. In addition, it inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) involved in cell proliferation and activation of early differentiation transcription factors in the mitotic clonal expansion (MCE) stage. As a result, ergosterol peroxide significantly inhibited the synthesis of triglycerides and differentiation of 3T3-L1 cells, and is, therefore, a possibile prophylactic and therapeutic agent for obesity and related metabolic diseases.

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