Fat Secretion Factor Urb And Regulation Of Obesity-related Research

Objective To study the expression of new adipokine URB during the normal differentiation process of 3T3-L1 preadipocytes on the mRNA and protein level. Then to observed the effects of reagents related to insulin sensity on the expressions of URB mRNA and URB protein in 3T3-L1 differetiating adipocytes and fully differentiated adipocytes.Still we also want to investigate the expression of URB in human subcutaneous adipose tissue and visceral adipose tissue in term of different BMI groups.Method 1.3T3-L1 preadipocytes were culture and induced to differentiate, and oil red 0 staining was conducted to identify the full differentiation of these cells.Treat the 3T3-L1 adipocytes with IL-6,TNF-α,insulin,DHT, E₂ and pioglitazone under diverse concentration and diverse time phase.Then the real time RT-PCR and western blot were used to measure the URB mRNA and protein expression level during the nomarl differentiation process and during other treated groups and contols at different time phase.2.Human subcutaneous adipose tissue and visceral adipose tissue were collected and all the subjects were sorted into different groups according to body mass index.Then realtime RT-PCR and western blot were used to measure the expression levels of URB mRNA and URB protein respectively.Results 1.The expression level of URB mRNA decreased mildly during the early period(day 0-day 2) of the whole differentiation process of 3T3-L1 preadipocytes,then it increased gradually with the differentiation proceeding to the end,and finally the expression level of URB was highest in fully differentiated adipocytes.The results from western blot showed the same pattern to that from realtime RT-PCR.2.In term of intervented differentiation groups comparing with the controls,the expression of URB was inhibited in IL-6 treated group,while this inhibition manner could be corrected by the addition of pioglitazone,but still the expression of URB showed no significant difference in the group treated with pioglitazone alone to the controls.3.As to the treatments to the differentiated 3T3-L1 adipocytes,inflammatory factors both IL-6 and TNF-αcould reduced the expression of URB in mature adipocytes in a dose-depengdent manner,still the expression of URB could also be inhibited by insulin and stanolone;while estradiol and pioglitazone could increase the expression of URB in mature 3r3-L1 adipocytes.4.According to initial exploratory research on human adipose tissue,we found that the expression level of URB is higher in visceral adipose tissue than that of subcutaneous tissue,and the expression levels of URB in adipose tissue of subjects with overweight or obesity were lower than that of people with normal weight.Conclusion 1.The new adipokine URB is related to adipogebesis of cells, and the expression level of URB mRNA and URB protein are the highest in mature adipocytes.2.The expression of URB is associated to insulin sensitivity, and URB could be regulated by nuclear transcription factor peroxisome proliferator-activated receptorsγ(PPARγ).3.In human visceral adipose tissue,URB expressed in a higher level than in subcutaneous adipose tissue, and the changes of URB expression maybe related to abnormal weight gain based on initial research.4.URB maybe be a protective factor of keeping balance of physical energy.