The Influence Of UVB Radiation On The TET2Gene Expression In Cultured Human Skin Fibroblast

Objectives:1.Fibroblasts were treated with different doses of UVB irritation, the cell proliferation activity was detected by MTT assay.2.To observe the expression of TET2gene in Fibroblasts which intervened by UVB irradiation.Methods:1.Using different doses of UVB irradiate each group of cultured Fibroblasts.2. Fibroblasts were treated by different doses of UVB irritation, the cell proliferation activity was detected by MTT assay.3.After intervened by different doses of UVB irradiation, using RT-PCR to assess the mRNA expression of hydroxymethylation related gene TET2of Fibroblasts.4.After intervened by different doses of UVB irradiation, assess the TET2protein in each group of Fibroblasts by Western-Blot.Results:1.Using daily dosage of10mJ/cm2UVB irritate the cultured Fibroblasts for five times,and then reinoculate the irritated fibroblasts, set the time when cells attached to the petri dish as0h, detected cell proliferation by MTT at0h,24h,48h,72h and96h, at each time point, the cell proliferation of experimemt group is different from the control group, the irritated HSF showed loss of replictive potential. The24h,48h,72h and96h experiment group express significant decrease in cell proliferation (p>0.05, while the0h experiment group had no significant change (p>0.05).2.When treated by daily dosage of10mJ/cm2UVB, the expression of TET2mRNA increased as the accumulate UVB dosage increasing, and reach a peak at the second day(when accumulate dosage is20mJ/cm2), after that, the expression droped a little,but still relatively higher than the control group, the TET2mRNA expression of20mJ/cm,30mJ/cm,40mJ/cm2,50mJ/cm2group are significantly higher than the control group (p<0.05), while the10mJ/cm2group have no significantly difference with the control group in TET2mRNA expression (p>0.05).3.According to the RT-PCR result of TET2mRNA expression in different accumulate dosage UVB irritation groups, detect the TET2protein of the groups exhibit significantly increased mRNA expression, which is20mJ/cm,30mJ/cm2,40mJ/cm and50mJ/cm group respectively, by Western-Blot, it turns out that each group selected presents a higher expression level of TET2protein than the blank control, while the20mJ/cm2and30mJ/cm2groups present a significant difference (p<00.05).Conclusion:1.The cell proliferation of Cultured Fibroblasts was inhibited when HSF was treated by proper dosage of UVB radiation, the fibroblasts present premature senesence biological characteristic.2.Cultured Fibroblasts treated by proper dosage of UVB radiation present an increased TET2expression, which suggests that demethylation may play a potential role in the photoaging mechenism.