| Objective:To explore the effect of advanced glycation end products on the mRNA and protein expression of adiponectin in 3T3-L1 adipocytes. So as to provide more theory support for prevention and cure of diabetes mellitus complicating atherosclerosis through founding the mechanism of action about AGE.Method:To prepare AGE-BSA, BSA was incubated with glucose in sodium phosphate buffer (pH 7.4) at 37oC for 60 days and dialyzed against PBS. Adipocytes were cultured and differentiated in vitro until mature adipocytes. These cells were incubated for 48 hours in the presence of 50μg/ml,100μg/ml,150μg/ml AGE-BSA, followed by assay for adiponectin synthesis and secretion by these cells. We established 2 control groups, unmodified BSA and phosphate-buffered saline (PBS). Adiponectin mRNA was quantitated by RT-PCR, while adiponectin concentrations in the culture medium were determined by ELISA kit.Result:1) By fluorospectrophotometer, we measure the fluorescence data of AGE-BSA is 12.25 while that of the BSA is just 0.42 after diluting 10 times respectively. The result meets the fluorescence characteristic of AGE. 2) There were lots of fat droplets in the mature adipocytes from the high power lens, and they are colored red by Oil Red O. 3) Having no significant difference between unmodified BSA and PBS. Adiponectin in differentiated adipocytes incubated with 50μg/ml AGE-BSA is less than that of the control groups (P<0.05). However, adiponectin is inhibited significantly in presence of the 100μg/ml,150μg/ml AGE as compared with that of the control groups(P<0.001). We survey the adiponectin concentrations by ELISA kit and get identical result. Along with the increasing AGE concentration, adiponectin expression is gradually decreasing.Conclusion::These results clarify that AGE-BSA are able to inhibit adiponectin synthesis at a mRNA level, leading to reduction in adiponectin secretion from these adipocytes, and this inhibition presents a dose-dependent manner.
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