| Objective : In this study,we investigated the effects of probiotics on lipid metabolism and insulin resistance by observing the expression of DAG and PKC in liver tissue of obese mice.Methods:(1)C57BL/6N male wild-type mice were fed with high-fat diet(HFD)or normal diet(NFD)for 8 weeks respectively,then the mice were weighed the weight(WT)to evaluate the modeling.the obese mice and the normal diet mice were divided into three groups: the living bacteria intervention group(VSL#3),the inactivated bacteria intervention group(Kill-VSL#3)and the double steaming water control group(control),and the intervention feeding continued for 4 weeks.(2)At the end of the 4th week after probiotics intervention,the mice in each group were fasting for 8 hours,blood was collected from the inner canthus vein,blood was collected from the anticoagulant tube,and the levels of total cholesterol(TC),triglyceride(TG),fasting blood glucose(FBG)and fasting insulin(FINS)were measured,and calculate the insulin resistance index.(3)At the end of the 4th week of probiotic intervention,mice fasted for 8 hours,weigh and record,the liver was extracted,and 50mg±5mg of liver tissue was taken,which was fully ground and centrifuged.(4)Enzyme linked immunosorbent assay(ELISA)was used to detect the contents of DAG and PKC in the liver of mice.Result:1.After 8 weeks of dietary intervention,WT in HFD group was significantly higher than that in NFD group(P<0.05);after 4 weeks of probiotic intervention,the levels of WT in high fat diet group(HFD+VSL#3group ? HFD+Kill-VSL#3 group ? HFD+Control group)were higher than those in NFD group on the intervention of probiotics with the same activity,the difference was statistically significant(p<0.05);under the same fat content diet conditions,the level of WT of HFD+VSL#3 group was lower than that of HFD+control group and HFD+Kill-VSL#3 group(p<0.05);there was no significant difference in WT between HFD+Kill-VSL#3 and HFD+control group(p>0.05);there was no significant difference between NFD+control group and NFD group after VSL#3 or inactivated VSL#3 treatment(p>0.05).2.After 12 weeks of intervention feeding,the levels of FBG,FINS and HOMA-IR in each group feed for high fat diet were higher than those in NFD group on the intervention of probiotics with the same activity,the difference was statistically significant(p<0.05);the levels of HFD+VSL#3 group of FBG,FINS and HOMA-IR decreased significantly than those of HFD+Kill-VSL#3 group and HFD+control group(p<0.05);there was no significant difference in FBG,FINS and HOMA-IR between HFD+Kill-VSL#3group and HFD+control group(p>0.05);however,there was no significant difference in FBG,FINS,HOMA-IR levels between NFD+control group and NFD+VSL#3 group and NFD+kill-VSL#3 group(p>0.05).3.Compared with each group of NFD on the intervention of probiotics with the same activity,each group of HFD had higher levels of blood TC and TG,and the difference was statistically significant(p<0.05);after probiotic intervention,campared with the HFD+control group and HFD+Kill-VSL#3 group,the levels of TC and TG in HFD+VSL#3 group decreased significantly(p<0.05);there was no significant difference between HFD+Kill-VSL#3 group and HFD+control group(p>0.05);there was no significant difference between each group fed with NFD in the TC and TG of blood(p > 0.05).4.Compared with each group of NFD on the intervention of probiotics with the same activity,the levels of DAG and PKC in liver tissue of each group of HFD were higher,the difference was statistically significant(p<0.05);after probiotic treatment,the expression of DAG and PKC in liver of HFD+VSL#3 group was lower than that of HFD+control group and HFD+Kill-VSL#3 group(p<0.05);there was no significant difference between HFD+Kill-VSL#3 group and HFD+control group(p>0.05);there was no significantdifference in DAG and PKC levels between NFD+Kill-VSL#3 group and NFD+control group and NFD+VSL#3 group(p>0.05).5.Pearson analysis showed that DAG was positively correlated with PKC expression in liver tissue;the level of DAG was positively correlated with WT,FBG and HOMA-IR;the level of PKC was positively correlated with TG,FBG and HOMA-IR.Conclusion:(1)High fat diet can up regulate the DAG-PKC signal pathway of obese mice to cause insulin resistance and lipid metabolism disorder;(2)Probiotics can improve insulin resistance mediated by obesity by down regulating DAG-PKC signaling pathway;... |
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