The roles of aerobic exercise training and suppression IL-6 gene expression by RNA interference in the development of insulin resistance

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• 作者：Hui Tang^a ; ^{tanghui19730711@163.com} ; Min-hao Xie^b ; Yu Lei^c ; Liang Zhou^a ; Yu-ping Xu^a ; Jian-guang Cai^a
• 关键词：Aerobic exercise training ; IL-6shRNA ; Insulin resistance ; Adiponectin ; Leptin
• 刊名：Cytokine
• 出版年：2013
• 出版时间：February, 2013
• 年：2013
• 卷：61
• 期：2
• 页码：394-405
• 全文大小：982 K

文摘

Objective

To demonstrate the hypothesis that aerobic exercise training inhibits the development of insulin resistance through IL-6 and probe into the possible molecular mechanism about it.

Methods

Rats were raised with high-fat diets for 8 weeks to develop insulin resistance, and glucose infusion rates (GIRs) were determined by hyperinsulinemic-euglycemic clamping to confirm the development of insulin resistance. Aerobic exercise training (the speed and duration time in the first week were respectively 16 m/min and 50 min, and speed increased 1 m/min and duration time increased 5 min every week following it) and/or IL-6shRNA plasmid injection (rats received IL-6shRNA injection via the tail vein every two weeks) were adopted during the development of insulin resistance. The serum IL-6, leptin, adiponectin, fasting blood glucose, fasting serum insulin, GIR, IL-6 gene expression levels, p-p38 in various tissues and p-STAT3/t-STAT3 ratio in the liver were measured.

Results

Rats fed with high-fat diets for 8 weeks were developed insulin resistance and the IL-6mRNA levels of IL-6shRNA injection groups in various tissues were significantly lower than those of control group (P < 0.05), respectively. The development of insulin resistance in exercise rats significantly decreased, however, compared with that, the GIR of exercise rats injected by IL-6shRNA was lower (P < 0.05). The IL-6mRNA levels were highest in the fat tissue and lowest in the skeletal muscles in all the rats. The serum adiponectin levels decreased (P < 0.05) following the development of insulin resistance, and it increased (P < 0.05) when the rats were intervened by aerobic exercise training for 8 weeks at the same time. However, there were not significant differences when serum leptin concentrations were compared (P > 0.05). The p-p38 significantly increased in the rats fed with high-fat diets, however, p-p38 of the exercise high-fat diets rats in the liver and fat tissues significantly decreased than that (P < 0.05). The changes of p-p38 in exercise rats injected by IL-6shRNA were irregular. The activation of STAT3 in the liver significantly increased (P < 0.05) following the development of insulin resistance, and it decreased (P < 0.05) when the rats were intervened by aerobic exercise training for 8 weeks at the same time, and the gene silencing of IL-6 did not have effects on the activation of STAT3 in the liver (P > 0.05).

Conclusions

In conclusion, aerobic exercise training prevented the development of insulin resistance through IL-6 to a certain degree. The gene expression and secretion of IL-6 could inhibit the development of insulin resistance. The mechanism of the effects were possibly related with elevating the levels of serum adiponectin, and/or inhibiting the activation of STAT3 in the liver and p38MAPK in the skeletal muscles, liver and fat tissues.