Expression and Significance of Lipin1 and AMPKα in Hepatic Insulin Resistance in Diet-Induced Insulin Resistance Rats

2012 ◽  
Vol 120 (02) ◽  
pp. 84-88 ◽  
Author(s):  
S. Chen ◽  
X. Zhuang ◽  
Y. Liu ◽  
A. Sun ◽  
C. Chen
Keyword(s):  
Insulin Resistance ◽  
High Fat Diet ◽  
Diet Group ◽  
Hepatic Insulin Resistance ◽  
Control Group ◽  
Mrna Levels ◽  
Ampk Signaling ◽  
Protein Levels ◽  
Obese Rats ◽  
Male Wistar Rats

AbstractLipin1, a lately indentified adipokine, may link obesity with insulin resistance and diabetes. The present study aimed to investigate the changes and significance of lipin1 expression and lipin1-AMPK signaling in diet-induced hepatic insulin resistance.24 4-week-old Male Wistar rats were randomly divided into 2 groups: (1) control group (CO), (2) high-fat diet group (HF). Insulin sensitivity was evaluated by hyperinsulinemic-euglycemic clamp technique. The mRNA levels of α1 and α2 subunit of AMPKα as well as Lipin1 were measured using Real-time RT-PCR. The activities of AMPKα and Akt were evaluated by detection of p-AMPKα (Thr-172) and p-Akt (ser473) by Western blot.After treatment of 4 months, HF group showed significantly increased levels of body weight, fasting plasma glucose and insulin levels; Plasma and liver total cholesterol (TC), triglycerides (TG) levels were also markedly elevated; Lipin1 expression at both mRNA and protein levels were significantly deceased. Compared with CO group, the mRNA and protein levels of AMPKα1 and AMPKα2 were not changed, whereas the p-AMPK (Thr-172) and p-AKT (ser473) levels in liver were significantly decreased in HF group.These findings indicated that the decrease in lipin1 expression and AMPKα activation may contribute to hepatic insulin resistance in diet-induced obese rats.

scholarly journals Protective role of melatonin against adipose-hepatic metabolic comorbidities in experimentally induced obese rat model

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260546
Author(s):  
Mary J. Obayemi ◽  
Christopher O. Akintayo ◽  
Adesola A. Oniyide ◽  
Ayodeji Aturamu ◽  
Olabimpe C. Badejogbin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Food Intake ◽  
High Fat Diet ◽  
Wistar Rats ◽  
Liver Lipid ◽  
Control Group ◽  
Metabolic Dysfunction ◽  
High Fat ◽  
Male Wistar Rats

Background Adipose and hepatic metabolic dysfunctions are critical comorbidities that also aggravate insulin resistance in obese individuals. Melatonin is a low-cost agent and previous studies suggest that its use may promote metabolic health. However, its effects on some comorbidities associated with obesity are unknown. Herein, we investigated the hypothesis that melatonin supplementation would attenuate adipose-hepatic metabolic dysfunction in high fat diet (HFD)-induced obesity in male Wistar rats. Materials and methods Twenty-four adult male Wistar rats (n = 6/group) were used: Control group received vehicle (normal saline), obese group received 40% high fat diet, melatonin-treated group received 4 mg/kg of melatonin, and obese plus melatonin group received 40% HFD and melatonin. The treatment lasted for 12 weeks. Results HFD caused increased food intake, body weight, insulin level, insulin resistance and plasma and liver lipid but decreased adipose lipid. In addition, HFD also increased plasma, adipose and liver malondialdehyde, IL-6, uric acid and decreased Glucose-6-phosphate dehydrogenase, glutathione, nitric oxide and circulating obestatin concentration. However, these deleterious effects except food intake were attenuated when supplemented with melatonin. Conclusion Taken together, the present results indicate that HFD exposure causes adipose-hepatic metabolic disturbance in obese animals, which are accompanied by oxidative stress and inflammation. In addition, the present results suggest that melatonin supplementation attenuates adipose-hepatic metabolic dysfunction, accompanying obesity by suppression of oxidative stress/inflammation-dependent mechanism and increasing circulating obestatin.

scholarly journals Evaluation of Liraglutide Effect on Serum Adipocytokines of Adults Male Wistar Rats with Insulin Resistance That Induced by High Fat Diet

2018 ◽  
pp. 122-132
Keyword(s):  
Insulin Resistance ◽  
Serum Level ◽  
Inflammatory Cytokines ◽  
High Fat Diet ◽  
Diet Group ◽  
High Fat ◽  
Male Wistar Rats ◽  
Anti Inflammatory ◽  
Glucagon Like Peptide 1 ◽  
Group B

Insulin resistance (IR) is the state in which insulin-stimulated glucose uptake is blunted in the insulin sensitive-tissue leading to state of prediabetes and T2DM, IR characterized by hyperglycemia and hyperinsulinemia in the fasting state, elevated glycosylated hemoglobin (HbA1c) level, hyperlipidemia, postprandial hyperglycemia, elevated plasma levels of pro-inflammatory markers and hypoadiponectinemia. Type 2 diabetes mellitus reported with peripheral insulin resistance (IR) and reduced production of insulin from pancreatic β-cells, IR elevates plasma fatty acids, decreasing glucose transportation to muscles and increased breakdown of fat finally leads to increased glucose production from the liver. This study was designed to evaluate the effect of liraglutide on serum adipocytokines of adult male rats with insulin resistance that induced by high fat diet, Chronic high fats diet feeding is a common cause of disturbing leptin signaling in hypothalamus leading to the state of hyperphagic obesity and leptin resistance. Liraglutide improve meal-stimulated insulin secretion so it's called incretin mimetic. It is glucagon like peptide-1 receptor agonist that adjust weight loss and glucose control via glucagon like peptide-1 receptors in the central nervous system or indirectly through activation of peripheral neurons. Current study utilized thirty-six adult male wistar rats (weighing 200-220gm), they were divided into two main groups: normal diet group (group A) that includes 12 rats receiving normal pellets and high fat diet group (group B and C) which has 24 rats feeding high fat diet pellets. Animals fed high fat diet pellets for 8 weeks to induce insulin resistance were divided into two groups: Group B received high fat diet pellets for 8 weeks then administered 0.5ml/kg normal saline intraperitoneal for four weeks. Group C received high fat diet pellets for 8 weeks then received 600μg/kg/day intraperitoneal liraglutide +0.5ml/kg normal saline four weeks along with high fat diet. High fat diet pellets caused a significant increase in body weight and blood glucose of high fat diet group. Liraglutide revealed a significant elevation in serum level of anti-inflammatory adipokines of group C. It also produces a significant reduction in serum level of pro-inflammatory cytokines of group C when compared with group B and control group. As conclusion, anti-inflammatory effects of liraglutide significantly elevate serum level of anti-inflammatory cytokines as well as significantly reduce serum level of pro-inflammatory cytokines.

YAP1 Overexpression Is Associated with Kidney Dysfunction in Lupus Nephritis

Pathobiology ◽  
2021 ◽  
pp. 1-12
Author(s):  
Ying Xie ◽  
Yuanyuan Ruan ◽  
Huimei Zou ◽  
Yixin Wang ◽  
Xin Wu ◽  
...  
Keyword(s):  
Lupus Nephritis ◽  
Epithelial Mesenchymal Transition ◽  
Kidney Tissue ◽  
Mouse Kidney ◽  
Experimental Comparison ◽  
Control Group ◽  
Mrna Levels ◽  
Mesenchymal Transition ◽  
Protein Levels

<b><i>Objective:</i></b> The goal of the present study was to determine the expression of yes-associated protein 1 (YAP1) in renal tissues of mice with lupus nephritis (LN) and elucidate its role in the progression of renal fibrosis. <b><i>Methods:</i></b> C57BL/6 mice and MRL/lpr mice were selected for experimental comparison. Mouse kidney tissues were removed and sectioned for hematoxylin and eosin staining, Masson’s trichome staining, Sirius staining, and immunohistochemistry. The mRNA and protein levels of YAP1 in mouse kidney tissues were detected, and the correlation between YAP1 and fibronectin (FN) mRNA levels was analyzed. Mouse renal epithelial cells were used for in vitro experiments. After transfection and stimulation, the cells were divided into 4 groups, namely the C57BL/6 serum group (group 1), the MRL/lpr serum group (group 2), the MRL/lpr serum + siRNA-negative control group (group 3), and the MRL/lpr serum + siRNA-YAP1 group (group 4). Epithelial-mesenchymal transition (EMT) markers in each group were detected by Western blotting and immunofluorescence staining. Serum creatinine, blood urea nitrogen, and urinary protein levels were detected and assessed for their correlation with YAP1 mRNA levels by Spearman’s analysis. <b><i>Results:</i></b> Compared to C57BL/6 mice, MRL/lpr mice exhibited obvious changes in fibrosis in renal tissues. In addition, YAP1 expression was significantly higher in the renal tissues of MRL/lpr mice than in those of C57BL/6 mice, and YAP1 mRNA levels were positively correlated with those of FN. YAP1 silencing in lupus serum-stimulated cells could effectively relieve serum-induced EMT. Finally, we observed that YAP1 mRNA levels in mouse kidney tissue were significantly and positively correlated with the degree of renal function injury. <b><i>Conclusion:</i></b> YAP1 expression in the kidney tissues of LN mice was higher than that observed in normal mice, indicating that YAP1 may play an important role in the occurrence and development of LN.

Time course of insulin resistance associated with feeding dogs a high-fat diet

1997 ◽  
Vol 272 (1) ◽  
pp. E147-E154 ◽  
Author(s):  
A. P. Rocchini ◽  
P. Marker ◽  
T. Cervenka
Keyword(s):  
Insulin Resistance ◽  
Blood Pressure ◽  
Glucose Uptake ◽  
Dose Response ◽  
High Fat Diet ◽  
Time Course ◽  
Rapid Development ◽  
Diet Group ◽  
Whole Body ◽  
High Fat

The current study evaluated both the time course of insulin resistance associated with feeding dogs a high-fat diet and the relationship between the development of insulin resistance and the increase in blood pressure that also occurs. Twelve adult mongrel dogs were chronically instrumented and randomly assigned to either a control diet group (n = 4) or a high-fat diet group (n = 8). Insulin resistance was assessed by a weekly, single-dose (2 mU.kg-1.min-1) euglycemic-hyperinsulinemic clamp on all dogs. Feeding dogs a high-fat diet was associated with a 3.7 +/- 0.5 kg increase in body weight, a 20 +/- 4 mmHg increase in mean blood pressure, a reduction in insulin-mediated glucose uptake [(in mumol-kg-1.min-1) decreasing from 72 +/- 6 before to 49 +/- 7 at 1 wk, 29 +/- 3 at 3 wk, and 30 +/- 2 at 6 wk of the high-fat diet, P < 0.01]. and a reduced insulin-mediated increase in cardiac output. In eight dogs (4 high fat and 4 control), the dose-response relationship of insulin-induced glucose uptake also was studied. The whole body glucose uptake dose-response curve was shifted to the right, and the rate of maximal whole body glucose uptake was significantly decreased (P < 0.001). Finally, we observed a direct relationship between the high-fat diet-induced weekly increase in mean arterial pressure and the degree to which insulin resistance developed. In summary, the current study documents that feeding dogs a high-fat diet causes the rapid development of insulin resistance that is the result of both a reduced sensitivity and a reduced responsiveness to insulin.

scholarly journals Microfibrillar-associated protein 5 regulates osteogenic differentiation by modulating the Wnt/β-catenin and AMPK signaling pathways

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Haoran Li ◽  
Wuling Zhou ◽  
Shiwei Sun ◽  
Tianlong Zhang ◽  
Tieqi Zhang ◽  
...  
Keyword(s):  
Osteogenic Differentiation ◽  
Molecular Mechanisms ◽  
Control Group ◽  
Signaling Proteins ◽  
Mrna Levels ◽  
Ampk Signaling ◽  
Marrow Mesenchymal Stem Cells ◽  
Osteogenic Induction ◽  
Overexpressing Cell ◽  
Gsk 3Β

Abstract Background Dysfunctional osteogenesis of bone marrow mesenchymal stem cells (BMSCs) plays an important role in osteoporosis occurrence and development. However, the molecular mechanisms of osteogenic differentiation remain unclear. This study explored whether microfibrillar-associated protein 5 (MFAP5) regulated BMSCs osteogenic differentiation. Methods We used shRNA or cDNA to knock down or overexpress MFAP5 in C3H10 and MC3T3-E1 cells. AR-S- and ALP-staining were performed to quantify cellular osteogenic differentiation. The mRNA levels of the classical osteogenic differentiation biomarkers Runx2, Col1α1, and OCN were quantified by qRT-PCR. Finally, we employed Western blotting to measure the levels of Wnt/β-catenin and AMPK signaling proteins. Results At days 0, 3, 7, and 14 after osteogenic induction, AR-S- and ALP-staining was lighter in MFAP5 knockdown compared to control cells, as were the levels of Runx2, Col1α1 and OCN. During osteogenesis, the levels of β-catenin, p-GSK-3β, AMPK, and p-AMPK were upregulated, while that of GSK-3β was downregulated, indicating that Wnt/β-catenin and AMPK signaling were activated. The relevant molecules were expressed at lower levels in the knockdown than control group; the opposite was seen for overexpressing cell lines. Conclusions MFAP5 regulates osteogenesis via Wnt/β‑catenin- and AMPK-signaling; MFAP5 may serve as a therapeutic target in patients with osteoporosis.

scholarly journals PO-043 The Effects of One-Time High Intensity Intermittent Training on Expression of LC3 Gene in Rats’ White Adipose Tissue

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Qishu Zhou ◽  
Chunyu Liang ◽  
Yafei Li ◽  
Yi Yan
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
High Intensity ◽  
High Fat Diet ◽  
Intermittent Exercise ◽  
Diet Group ◽  
Control Group ◽  
High Fat ◽  
Subcutaneous White Adipose Tissue ◽  
White Fat

Objective  To investigate the effect of one-time high-intensity intermittent exercise in white fat autophagy in obese rats and provide a theoretical basis of the molecular mechanism of exercise fat loss. Methods  Eighteen male 3-weeks-old rats were selected and divided into control group fed with normal diet (C), high-fat diet group fed with high fat diet (H). After 16 weeks, there were twelve obesity rats that divided into diet group (HS) and exercise group (HE). The other six control group rats of 19 weeks age were used as the standard (CS group). OE group did the high intensity intermittent exercise once. The CS group and the CS group were kept quietly. Three groups were taken subcutaneous white adipose tissue(S) and epididymal white adipose tissue (E) immediately after exercise. Mensurate the expression of LC3 gene in the tissue using the fluorescent quantitative PCR. Results 1. The expression of LC3 mRNA from white fat tissue was different to the tissues, which the expression of epididymal white adipose tissue of each group was higher than that in subcutaneous white adipose tissue (P <0.01). 2. Compared with CS group, the expression of epididymal white fat adipose tissue LC3 mRNA decreased (P<0.01) and the expression of the subcutaneous white adipose tissue increased from HS group (P <0.05). 3. Compared with OS group, the expression of epididymal white fat adipose tissue LC3 mRNA decreased (P<0.05) and the expression of subcutaneous white adipose tissue decreased from OS group. Conclusions The expression of LC3mRNA in epididymal white fat adipose tissue of rats was significantly higher than that of subcutaneous white fat. The changes of LC3mRNA expression of adipose tissue caused by high-fat diet have tissue differences. One-time high-intensity intermittent exercise can reduce the expression of LC3mRNA in fat tissue of obese rats. Its regulatory mechanism needs to be further studied.

scholarly journals CaMKIV limits metabolic damage through induction of hepatic autophagy by CREB in obese mice

2020 ◽  
Vol 244 (2) ◽  
pp. 353-367 ◽  
Author(s):  
Jiali Liu ◽  
Yue Li ◽  
Xiaoyan Zhou ◽  
Xi Zhang ◽  
Hao Meng ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Inflammatory Response ◽  
Mitochondrial Dysfunction ◽  
High Fat Diet ◽  
Insulin Action ◽  
Hepatic Insulin Resistance ◽  
Obese Mice ◽  
High Fat ◽  
Impaired Insulin

High-fat diet (HFD) not only induces insulin resistance in liver, but also causes autophagic imbalance and metabolic disorders, increases chronic inflammatory response and induces mitochondrial dysfunction. Calcium/calmodulin-dependent protein kinase IV (CaMKIV) has recently emerged as an important regulator of glucose metabolism and skeletal muscle insulin action. Its activation has been involved in the improvement of hepatic and adipose insulin action. But the underlying mechanism is not fully understood. In the present study, we aimed to address the direct effects of CaMKIV in vivo and to evaluate the potential interaction of impaired insulin sensitivity and autophagic disorders in hepatic insulin resistance. Our results indicated obese mice receiving CaMKIV showed decreased blood glucose and serum insulin and improved insulin sensitivity as well as increased glucose tolerance compared with vehicle injection. Meanwhile, defective hepatic autophagy activity, impaired insulin signaling, increased inflammatory response and mitochondrial dysfunction in liver tissues which are induced by high-fat diet were also effectively alleviated by injection of CaMKIV. Consistent with these results, the addition of CaMKIV to the culture medium of BNL cl.2 hepatocytes markedly restored palmitate-induced hepatic insulin resistance and autophagic imbalance. These effects were nullified by blockade of cyclic AMP response element-binding protein (CREB), indicating the causative role of CREB in action of CaMKIV. Our findings suggested that CaMKIV restores hepatic autophagic imbalance and improves impaired insulin sensitivity via phosphorylated CREB signaling pathway, which may offer novel opportunities for treatment of obesity and diabetes.

scholarly journals Combined effects of low-dose gambogic acid and NaI131 in drug-resistant non-small-cell lung cancer cells

2020 ◽  
Author(s):  
Jing Huang ◽  
Ming Ding ◽  
Ying Wu ◽  
Shuhua Han ◽  
Yan Xie ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Low Dose ◽  
Small Cell ◽  
Cyclin B ◽  
Gambogic Acid ◽  
Control Group ◽  
Mrna Levels ◽  
Drug Resistant ◽  
Small Cell Lung ◽  
Protein Levels

Abstract Background Radioactive seed is a method for treating drug-resistant, late-stage non-small cell lung cancer (NSCLC), but has undesirable side effects. Gambogic acid (GA), an ingredient of traditional Chinese medicine, exerts broad-spectrum antitumour activities via several pathways. This study aimed to elucidate the mechanism involved in the combined effect of low-dose GA and NaI131 to sensitize the antitumour activity of NaI131 in drug-resistant NSCLC cells. Methods Human NSCLC cell line A549 and drug-resistant cell lines A549/DDP and A549/Taxol were treated with NaI131, low-dose GA or a combination of both; control group of each cell line was treated with phosphate-buffered saline. Following treatment, cell proliferation, apoptosis, cell cycle, and levels of expression of apoptosis-related proteins namely CDK1, Cyclin B, mtp53, HSP90, and Bax, Bcl-2 respectively, and P-glycoprotein 1 (P-gp) known to confer resistance to chemotherapy, were detected using western blotting and immunofluorescence. mRNA levels of mtp53 and HSP90 were measured using qRT-PCR. Results Compared to the control group, A549, A549/DDP, and A549/Taxol cells treated with NaI131, GA or combination of drugs exhibited G2/M arrest, increased percentage of total apoptotic cells, significantly reduced protein levels of CDK1, Cyclin B, mtp53, HSP90, Bcl-2 and P-gp, increased protein levels of Bax and decreased mRNA levels of mtp53 and HSP90. The changes in the combination group were significantly different from the other groups. Conclusion In NSCLC cell lines, low-dose GA could enhance the effect of NaI131 on G2/M arrest, promote cell apoptosis, reduce drug-resistance and hence could be explored as a potential radionuclide sensitizer.

scholarly journals Histologi Lumen Dan Endotelium Arteri Dorsal Penis Tikus Wistar (Rattus Novergicus) Yang Diinduksi Pakan Tinggi Lemak

2020 ◽  
Vol 7 (1) ◽  
pp. 73
Author(s):  
I Wayan Rosiana ◽  
I Gede Widhiantara
Keyword(s):  
Treatment Group ◽  
High Fat Diet ◽  
Wistar Rats ◽  
Wistar Rat ◽  
Lumen Diameter ◽  
Control Group ◽  
High Fat ◽  
Arterial Lumen ◽  
Male Wistar Rats ◽  
The Difference

This study aims to look at the histopathological picture of the dorsal arteries of the penis of the hiperlipidemic wistar rats (Rattus novergicus) induction by high-fat diet that seen in terms of lumen diameter and thickness of the arterial endotelium wall. Hyperlipidemia is a risk factor for ateriosclerosis in the penile arteries causing erectile dysfunction in men. This study is an experimental study with a randomized posttest only control goup design. The sample are  10 individuals adult male wistar rats aged 3-4 months with a range of body weight 150-200 grams. Before treatment, adaptation was carried out for 7 days. After that the sample rats in the treatment group were made hyperlidemic by feeding lard for 50 days. Then surgery is performed for histopathological preparations at the posttest. To determine the differences in endotelium thickness and arterial lumen diameter in the two groups, an independent t-test was used. Thick diameter data of the endotelium and dorsal arteries of the penis of the wistar rat between the lower treatment group and the control group. The difference that occurred was statistically significant (p <0.05). So it can be concluded that the provision of high-fat diet (hyperlipidemia) decreases the lumen diameter and endotelium thickness of dorsal arteries penis. Keywords: Dorsal arteries, high-fat diet, Wistar rats

scholarly journals Duration of rise in free fatty acids determines salicylate's effect on hepatic insulin sensitivity

2013 ◽  
Vol 217 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Sandra Pereira ◽  
Wen Qin Yu ◽  
María E Frigolet ◽  
Jacqueline L Beaudry ◽  
Yaniv Shpilberg ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Muscle Protein ◽  
Hepatic Insulin Resistance ◽  
Skeletal Muscle Protein ◽  
Protein Levels ◽  
Peripheral Insulin Resistance ◽  
Plasma Ffa ◽  
A Site

We have shown in rats that sodium salicylate (SS), which inhibits IkBa kinase B (IKKB), prevents hepatic and peripheral insulin resistance caused by short-term (7 h) i.v. administration of Intralipid and heparin (IH). We wished to further determine whether this beneficial effect of SS persisted after prolonged (48 h) IH infusion, which better mimics the chronic free fatty acid (FFA) elevation of obesity. Hence, we performed hyperinsulinemic euglycemic clamps with tritiated glucose methodology to determine hepatic and peripheral insulin sensitivity in rats infused with saline, IH, IH and SS, or SS alone. SS prevented peripheral insulin resistance (P<0.05) caused by prolonged plasma FFA elevation; however, it did not prevent hepatic insulin resistance. In skeletal muscle, protein levels of phospho-IkBa were augmented by prolonged IH administration and this was prevented by SS, suggesting that IH activates while SS prevents the activation of IKKB. Markers of IKKB activation, namely protein levels of phospho-IkBa and IkBa, indicated that IKKB is not activated in the liver after prolonged FFA elevation. Phosphorylation of serine 307 at insulin receptor substrate (IRS)-1, which is a marker of proximal insulin resistance, was not altered by IH administration in the liver, suggesting that this is not a site of hepatic insulin resistance in the prolonged lipid infusion model. Our results suggest that the role of IKKB in fat-induced insulin resistance is time and tissue dependent and that hepatic insulin resistance induced by prolonged lipid elevation is not due to an IRS-1 serine 307 kinase.

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