Dynamic Variation Of SH2B1, SOCS3 And PTP1B MRNA Expression In Obese Mice Hypothalamus

OBJECTIVES:The aim of this study was to compare the difference of SH2B1-,SOCS3-, PTP1B-mRNA expression and leptin level in obesity and normal mice in different age, and to explore the variation of SH2B1-,SOCS3-,PTP1B-mRNA expression and the association with serum leptin level in obese mice.METHODS:60 C57/b16 mice(male and female in equal) aged 6 weeks were used throughout the study. Mice were randomized to a standard rodent chow (NC,n=24) or to a high fat diet chow (HFD,n=36). After 6 weeks on the diet, all mice were randomly divided into two groups,12 standard rodent chow mice and 11 obese mice (DIO,which were chosen from the 18 HFD mice),were sacrificed for measurement of body length(from top of nose to anus) and body weight. Blood serum was separated by centrifugation and samples stored at-70℃until further use. Abdominal adipose tissues were isolated and fixed in Bouins' solution,paraffin sections were prepared and stained with H&E. Images were visualized using microscope and captured using Digital Camera. The rest 12 standard rodent chow mice and 13 obese mice (DIO,which were chosen from the 18 HFD mice) were sacrificed when they were 24 weeks old. Blood serum and tissues of the mice were collected as above. Triglyceride(TG) was determined by automatic biochemistry analyzer Blood glucose concentration (FPG) was determined using glucose oxidase; The fasting plasma insulin (FINS) was tested by radioimmunoassay(RIA); Serum leptin concentration was measured using a Radioimmunoassay Kit (ELISA); HOMA-IR and Lee's index [(wt(g)1/3*1000/length(cm)] was Calculated. Total RNA for gene expression analysis were isolated from hypothalamus tissues, RT-PCR was used to detect the expression of SH2B1, SOCS3 and PTP1B. The real time PCR was performed to detect the expression of SH2B1, SOCS3 and PTPlB.RESULTS:①Compared with the NC group, Wt, Lee's index, FPG, TG, LEP, FINS and HOMA-IR were increased in both 12-and 24-week-old DIO group.②The levels of LEP, FINS and HOMA-IR in 24-week-old DIO group were higher than that of the 12-week-old DIO group,but there was no significant difference between 12-and 24-week-old NC group.③Compared with the NC group,the SH2B1-mRNA expression of 12-and 24-week-old DIO groups were lower,but the SOCS3-and PTP1B-mRNA expression of 12-and 24-week-old DIO groups were higher.④Compared with the 12-week-old DIO group,the SH2B1-mRNA expression were lower than that of the 24-week-old DIO group,but the SOCS3-and PTP1B-mRNA expression were higher than that of the 12-week-old DIO group.⑤Compared with the 12-week-old NCgroup, the SOCS3-and PTP1B-mRNA expression were higher than that of the 12-week-old NCgroup,but the SH2B1 mRNA expression had no significant difference between 12-and 24-week-old NCgroup.⑥The level of serum LEP was negatively correlated with the expression of SH2B1mRNA, positively correlated with the expressions of SOCS3-and PTP1B-mRNA.CONCLUSIONS:①The SH2B1mRNA expression of obese mice were lower than that of the normal ones,the SOCS3-and PTP1B-mRNA expressions were higher than that of the normal ones.②In obese mice,the SH2B1mRNA expression showed a decreasing trend with ageing, the SOCS3-and PTP1B-mRNA expressions showed an increasing trend with ageing.③In normal mice, the SOCS3-and PTP1B-mRNA expressions showed an increasing trend with ageing,but the SH2B1-mRNA expression had no change.