scholarly journals Swimming Exercise Alleviated Insulin Resistance by Regulating Tripartite Motif Family Protein 72 Expression and AKT Signal Pathway in Sprague-Dawley Rats Fed with High-Fat Diet

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Jie Qi ◽  
Bo Yang ◽  
Cailing Ren ◽  
Jian Fu ◽  
Jun Zhang

We aimed to investigate whether swimming exercise could improve insulin resistance (IR) by regulating tripartite motif family protein 72 (TRIM72) expression and AKT signal pathway in rats fed with high-fat diet. Five-week-old rats were classified into 3 groups: standard diet as control (CON), high-fat diet (HFD), and HFD plus swimming exercise (Ex-HFD). After 8 weeks, glucose infusion rate (GIR), markers of oxidative stress, mRNA and protein expression of TRIM72, protein of IRS, p-AKTSer473, and AKT were determined in quadriceps muscles. Compared with HFD, the GIR, muscle SOD, and GSH-Px were significantly increased (p<0.05, resp.), whereas muscle MDA and 8-OHdG levels were significantly decreased (p<0.05andp<0.01) in Ex-HFD. Expression levels of TRIM72 mRNA and protein in muscles were significantly reduced (p<0.05andp<0.01), whereas protein expression levels of IRS-1, p-AKTSer473, and AKT were significantly increased in Ex-HFD compared with HFD (p<0.01,p<0.01, andp<0.05). These results suggest that an 8-week swimming exercise improves HFD-induced insulin resistance maybe through a reduction of TRIM72 in skeletal muscle and enhancement of AKT signal transduction.

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Jiexiu Zhao ◽  
Fei Qin ◽  
Minxiao Xu ◽  
Yanan Dong ◽  
Zhongwei Wang ◽  
...  

Objective  Insulin resistance (IR) is associated with many related health complications. Previous studies demonstrate that heat and exercise independently reduce IR. The purpose of this study was to test the hypothesis that combined exercise and heating is even more favorable in reducing IR. Methods Male Wistar rats were randomly divided into five groups: exercise (NE; n=10), heated (HC; n=10), exercise and heated (HE; n=10), sedentary (NC; n=10), and normal diet plus sedentary (CC; n=10). All but the latter group was fed a high-fat diet (60% calories from fat) for 10 weeks while receiving heat and/or exercise exposure for latter 8 weeks. Following this regimen, protein expression from the soleus and extensor digitorum longus muscles, serum, and brown fat were analyzed using Western blotting. Results Exercise combined with heating shifted the metabolic characteristics of rats on a high-fat diet toward that observed in the rats on a standard diet. Specifically, eight weeks of combined heat and endurance exercise increased PGC-1α, CnA, CaMKIV and p38 MAPK protein expression in the soleus (P < 0.05), insulin protein expression in the serum (P < 0.05), and UCP1 protein expression in the brown fat (P < 0.05), when compared to the high fat fed sedentary group. There were some significant differences in responses (i.e., body weight and Leptin & Adiponectin concentrations) between the combined exercise and heat group relative to the exercise alone group. Conclusions  Exercise combined with heat exposure mitigates the development of IR, presumably from the Irisin pathway. The study provides potential non-pharmaceutical methods for therapeutic treatment of IR.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Rieko Takanabe ◽  
Koh Ono ◽  
Tomohide Takaya ◽  
Takahiro Horie ◽  
Hiromichi Wada ◽  
...  

Obesity is the result of an expansion and increase in the number of individual adipocytes. Since changes in gene expression during adipocyte differentiation and hypertrophy are closely associated with insulin resistance and cardiovascular diseases, further insight into the molecular basis of obesity is needed to better understand obesity-associated diseases. MicroRNAs (miRNAs) are approximately 17–24nt single stranded RNA, that post-transcriptionally regulate gene expression. MiRNAs control cell growth, differentiation and metabolism, and may be also involved in pathogenesis and pathophysiology of diseases. It has been proposed that miR-143 plays a role in the differentiation of preadipocytes into mature adipocytes in culture. However, regulated expression of miR-143 in the adult adipose tissue during the development of obesity in vivo is unknown. To solve this problem, C57BL/6 mice were fed with either high-fat diet (HFD) or normal chow (NC). Eight weeks later, severe insulin resistance was observed in mice on HFD. Body weight increased by 35% and the mesenteric fat weight increased by 3.3-fold in HFD mice compared with NC mice. We measured expression levels of miR-143 in the mesenteric fat tissue by real-time PCR and normalized with those of 5S ribosomal RNA. Expression of miR-143 in the mesenteric fat was significantly up-regulated (3.3-fold, p<0.05) in HFD mice compared to NC mice. MiR-143 expression levels were positively correlated with body weight (R=0.577, p=0.0011) and the mesenteric fat weight (R=0.608, p=0.0005). We also measured expression levels in the mesenteric fat of PPARγ and AP2, whose expression are deeply involved in the development of obesity, insulin resistant and arteriosclerosis. The expression levels of miR-143 were closely correlated with those of PPARγ (R=0.600, p=0.0040) and AP2 (R=0.630, p=0.0022). These findings provide the first evidence for up-regulated expression of miR-143 in the mesenteric fat of HFD-induced obese mice, which might contribute to regulated expression of genes involved in the pathophysiology of obesity.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Camila O. Souza ◽  
Alexandre A. S. Teixeira ◽  
Edson A. Lima ◽  
Helena A. P. Batatinha ◽  
Lara M. Gomes ◽  
...  

Palmitoleic acid (PMA) has anti-inflammatory and antidiabetic activities. Here we tested whether these effects of PMA on glucose homeostasis and liver inflammation, in mice fed with high-fat diet (HFD), are PPAR-αdependent. C57BL6 wild-type (WT) and PPAR-α-knockout (KO) mice fed with a standard diet (SD) or HFD for 12 weeks were treated after the 10th week with oleic acid (OLA, 300 mg/kg of b.w.) or PMA 300 mg/kg of b.w. Steatosis induced by HFD was associated with liver inflammation only in the KO mice, as shown by the increased hepatic levels of IL1-beta, IL-12, and TNF-α; however, the HFD increased the expression of TLR4 and decreased the expression of IL1-Ra in both genotypes. Treatment with palmitoleate markedly attenuated the insulin resistance induced by the HFD, increased glucose uptake and incorporation into muscle in vitro, reduced the serum levels of AST in WT mice, decreased the hepatic levels of IL1-beta and IL-12 in KO mice, reduced the expression of TLR-4 and increased the expression of IL-1Ra in WT mice, and reduced the phosphorylation of NF𝜅B (p65) in the livers of KO mice. We conclude that palmitoleate attenuates diet-induced insulin resistance, liver inflammation, and damage through mechanisms that do not depend on PPAR-α.


2021 ◽  
Author(s):  
Xiaojun Ma ◽  
Yujie Guo ◽  
Pengfei Li ◽  
Jingjing Xu ◽  
Shengqi Dong ◽  
...  

Abstract Background: Type 2 diabetes mellitus (T2DM) and Alzheimer’s disease (AD) are two prevalent diseases with comparable pathophysiological features and genetic predisposition. Polyunsaturated fatty acids (PUFAs) are essential in maintaining normal brain function. However, little is known about the impact of dietary n-6/n-3 PUFA ratio on AD-like pathology, especially in high-fat diet (HFD)-fed AD model mice. Methods: In the present study, the APP/PS1 mice were treated with 60% HFD for 3.5 months to induced insulin resistance. After that, 45% HFD with different n-6/n-3 PUFA ratios (n-6/n-3=1:1, 5:1 or 16:1) was applied for additional 3.5 months treatment. Following the dietary intervention, the behavior of mice was observed using the Water maze. Following behavioral testing, the animals were euthanized, and serum and tissue samples were collected for biochemical, histological and pathological analyses and evaluation. Cortical fatty acid profile was measured by gas chromatography. Western Blot and immunohistochemistry methods were used to detect protein expression of molecules related to AD pathology and insulin signaling pathway(s) in the brain sample tissues. Immunofluorescence assay was used to uncover the expression and migration of NF-κB in the cortex. qPCR method was applied to determine the gene expression of cortical pro-inflammatory cytokines.Results: HFD caused insulin resistance, increased serum IL-6 and TNF-α level, elevated cortical soluble Aβ1-40, Aβ1-42 content, and increased brain n-6/n-3 PUFAs ratio in APP/PS1 mice. Increased APP and BACE1 protein expression and p-IR/IR ratio, but decreased pro-inflammatory cytokines mRNA expression was observed in the cortex from 60% HFD-fed APP/PS1 mice. N-3 PUFAs rich diet (n-6/n-3=1:1) relieved insulin resistance and hyperlipidemia induced by 60% HFD. Cortical soluble Aβ1-40 and Aβ1-42 contents, the expression of cortical APP, GLUT3, insulin metabolism related molecules, and NF-κB pathway downstream pro-inflammatory cytokines showed a dietary n-6/n-3 PUFAs ratio-dependent way, indicating that dietary n-6/n-3 PUFA ratio plays a critical role in modifying the responses of serum inflammatory cytokine, AD pathology, cortical n-6/n-3 PUFAs ratio, insulin signaling and neuroinflammation to HFD treatment.Conclusion: Dietary n-6/n-3 PUFA ratio play an important role in modifying AD pathophysiology, insulin signaling pathway, and neuro-inflammation response to high fat diet treatment in brain.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
N Wada ◽  
H Yamada ◽  
S Motoyama ◽  
M Saburi ◽  
T Sugimoto ◽  
...  

Abstract Background Maternal high-fat diet (HFD) has been shown to promote the development of insulin resistance (IR) in adult offspring; however, the underlying mechanisms remain unclear. Approach and results Eight-week-old female wild-type mice (C57BL/6) were fed a HFD or normal diet (ND) one week prior to mating, and received during pregnancy and lactation. Eight-week-old male offspring of both groups were fed a HFD for 8 weeks. Offspring of HFD-fed dams (O-HFD) showed significantly enhanced IR compared with offspring of ND-fed dams (O-ND). There was no difference in body weight, epidydimal white adipose tissue (eWAT) weight, and cumulative caloric intake between the 2 groups. However, eWAT adipocyte size was significantly increased in O-HFD, accompanied by the abundant crown-like structures. Flow cytometric analysis revealed an increased percentage of M1, but not M2, macrophages. Serum and eWAT concentrations of IL-1β, but not TNF-α, were significantly higher in O-HFD than O-ND (3.7-fold and 2.0-fold, respectively, P<0.05). Treatment with NLRP3 inflammasome inhibitor MCC950 completely abrogated the enhanced IR in O-HFD to a similar extent of that in O-ND, although IR was modestly, but not significantly, ameliorated in O-ND even after MCC950 treatment. Consistent with in vivo findings, in vitro polarization of bone marrow-derived macrophages (BMDMs) did not show any difference in TNF-α mRNA expression after conventional stimulation. In contrast, palmitate acid (PA)-mediated metabolic activation of BMDMs following LPS priming showed a significantly higher concentration of IL-1β in culture supernatants from O-HFD (45%, P<0.05). However, protein expression levels of NLRP-3, ASC, and procaspase-1 after LPS priming were equivalent between the 2 groups. Consistently, intracellular flow cytometric analysis of caspase-1 activity after PA activation did not show any difference, which was compatible with the finding that ex vivo caspase-1 activity of eWAT assessed by fluorescent image of IVIS revealed no difference between the 2 groups. To further examine the mechanism of augmented IL-1β release in BMDM of O-HFD, we examined the cleavage of caspase substrate gasdermin D (GSDMD) and subsequent pore formation. Protein and gene expression levels of GSDM-D after LPS priming were significantly higher in O-HFD (50% and 381%, respectively, P<0.05). At 2 hrs after PA stimulation following LPS priming, cleaved GSDM-D was significantly increased in O-HFD (80%, P<0.01). Consistently, percentage of pore formation assessed by ethidium bromide staining was significantly higher in O-HFD (60%, P<0.05), while LDH release could not be observed. Conclusions Our findings demonstrate that maternal HFD exaggerates diet-induced insulin resistance in adult offspring by enhancing pyroptosis through augmented GSDM-D-mediated pore formation.


2010 ◽  
Vol 108 (4) ◽  
pp. 933-940 ◽  
Author(s):  
Marie-Claude Aubin ◽  
Sophie Cardin ◽  
Philippe Comtois ◽  
Robert Clément ◽  
Hugues Gosselin ◽  
...  

Obesity increases the incidence of cardiac arrhythmias and impairs wound healing. However, it is presently unknown whether a high-fat diet affects arrhythmic risk or wound healing before the onset of overt obesity or hyperlipidemia. After 8 wk of feeding a high-fat diet to adult female rats, a nonsignificant increase in body weight was observed and associated with a normal plasma lipid profile. Following ischemia/reperfusion injury, scar length (standard diet 0.29 ± 0.09 vs. high-fat 0.32 ± 0.13 cm), thickness (standard diet 0.047 ± 0.02 vs. high-fat 0.059 ± 0.01 cm), and collagen α1 type 1 content (standard diet 0.21 ± 0.04 vs. high-fat 0.20 ± 0.04 arbitrary units/mm2) of infarcted hearts were not altered by the high-fat diet. However, the mortality rate was greatly increased 24 h postinfarction (from 5% to 46%, P < 0.01 for ischemia/reperfusion rats; from 20% to 89%, P < 0.0001, in complete-occlusion rats) in high-fat fed rats, in association with a higher prevalence of ventricular arrhythmias. Ventricular arrhythmia inducibility was also significantly increased in noninfarcted rats fed a high-fat diet. In the hearts of rats fed a high-fat diet, connexin-40 expression was absent, connexin-43 was hypophosphorylated and lateralized, and neurofilament-M immunoreactive fiber density (standard diet 2,020 ± 260 vs. high-fat diet 2,830 ± 250 μm2/mm2) and tyrosine hydroxylase protein expression were increased ( P < 0.05). Thus, in the absence of overt obesity and hyperlipidemia, sympathetic hyperinnervation and an aberrant pattern of gap junctional protein expression and regulation in the heart of female rats fed a high-fat diet may have contributed in part to the higher incidence of inducible cardiac arrhythmias.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Andre Bento Chaves Santana ◽  
Thais Cristina de Souza Oliveira ◽  
Barbara Lobo Bianconi ◽  
Valerio Garrone Barauna ◽  
Ed Wilson Cavalcante Oliveira Santos ◽  
...  

Changes in lifestyle such as increase in high-fat food consumption are an important cause for vascular diseases. The present study aimed to investigate the involvement of ACE and TGF-βin the aorta stiffness induced by high-fat diet. C57BL/6 male mice were divided in two groups according to their diet for 8 weeks: standard diet (ST) and high-fat diet (HF). At the end of the protocol, body weight gain, adipose tissue content, serum lipids and glucose levels, and aorta morphometric and biochemical measurements were performed. Analysis of collagen fibers by picrosirius staining of aorta slices showed that HF diet promoted increase of thin (55%) and thick (100%) collagen fibers deposition and concomitant disorganization of these fibers orientations in the aorta vascular wall (50%). To unravel the mechanism involved, myeloperoxidase (MPO) and angiotensin I converting enzyme (ACE) were evaluated by protein expression and enzyme activity. HF diet increased MPO (90%) and ACE (28%) activities, as well as protein expression of ACE. TGF-βwas also increased in aorta tissue of HF diet mice after 8 weeks. Altogether, we have observed that the HF diet-induced aortic stiffening may be associated with increased oxidative stress damage and activation of the RAS in vascular tissue.


2021 ◽  
Vol 10 (13) ◽  
pp. e298101321369
Author(s):  
Juliana Maganha Abreu ◽  
Gérsika Bitencourt Santos ◽  
Maria das Graças de Souza Carvalho ◽  
Juliana Marques Mencarelli ◽  
Bruna Rayanne Moreira Cândido ◽  
...  

Introduction: The synthesis ovarian’s steroids is a process thats depends on the supply of cholesterol. Objective: to evaluate the influence of dyslipidemia on the secretion ovarian’s steroids. Methodology: wild female mice were used (C57BL6) and LDL (LDLR-/-), which they were separated into 4 groups (n = 10): WTS: fed a standard diet; WTHL: fed a high-fat diet; KOS: fed a standard diet; KOHL: fed a high-fat diet. After 60 days, the estrous cycle was analyzed and after anesthetized, blood was collected for the to assess the lipid profile, glucose, plasma insulin level and HOMA index was calculated. In addition, plasma levels of C-reactive protein, estrogen and progesterone were determined. Results: The hyperlipidic diet in both the WTHL and the KOHL group generated hypercholesterolemia when compared to the WTS and KOS, respectively, with a decrease in HDLc, associated with an increase in CRP levels. Severe hypercholesterolemia in the KOHL group generated insulin resistance, marked by an increase in HOMAir. Food hypercholesterolemia in the WTHL group, food and genetics in the KOHL group, compared to their WTS and KOS controls, was definitive in reducing plasma levels of estrogen and progesterone. The genetic hypercholesterolemia associated with insulin resistance observed in the KOS and KOHL groups reduced the levels of progesterone, this reduction being more severe in the KOHL group, which had the highest HOMAir. Conclusion: dyslipidemia affected ovarian steroidogenesis in mice by means of oxidative stress, inflammation and insulin resistance and / or by decreasing HDL cholesterol levels.


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