The Study Of Androgen Modulated Sebum Secretion In Acne Via Autophagy Repression

Background:Androgen has been regarded as the strongest stimulator for the formation of sebum and proliferation of sebocytes in patients with acne,but the underlying mechanisms still need to be addressed.Recently,autophagy has been suggested to be involved in the decomposition of lipids and the regulation of proliferation.The previous studies have shown that the secretion of sebaceous gland cells can be regulated by autophagy.In addition,androgens can regulate autophagy in a variety of cells.Therefore,it is speculated whether androgen can regulate the secretion of sebaceous gland cells through autophagy and aggravate acne.To verify this hypothesis,we designed this experiment.Part 1Objective:To investigate the effect of androgen on sebum secretion in acne patients via autophagy repression.Methods:A total of 68 female patients with acne treated in the Dermatology Department were selected as the observation group and treated with antiandrogens(ethinyl estradiol progesterone tablets)for 3 months.Another 68 normal women without acne were selected as the control group.The levels of serum androgen dihydrotestosterone(Dihydrotestosterone,DHT),sebum-secreted triglyceride(Triglyceride,TG)before and after treatment in the control and observation groups were measured,the size of sebaceous gland and the levels of autophagic marker proteins LC3-Ⅱ were detected,and the differentially expression of lncRNA and mRNA.Results:The DHT level of the observation group before the treatment wash higher than the control group,and the DHT level of the observation group was lower than that of the control group before treatment and was lower than that of the control group(P<0.05).Before treatment(P<0.05),it was close to the TG level in the control group(P>0.05).The size of sebaceous gland in the observation group after treatment was larger than that of the observation group before treatment and control group.The contents of LC3-Ⅱ in the observation group were lower than the contents of LC3-Ⅱ in the control group,and the levels of LC3-Ⅱ were increased after treatment.Higher than the control group(P<0.05).Before treatment,the transcription level of PIK3R3 in mTOR signaling pathway was significantly down-regulated(P<0.01),however,it was significantly up-regulated after treatment(P<0.01).Meanwhile,before treatment,the lncRNA E2F3-IT1 was significantly down-regulated(P<0.01),however,it was significantly up-regulated after treatment(P<0.01).Conclusion:Androgen-mediated autophagy inhibition can promote secretion of sebum,possibaly targed on PI3K-AKT-mTOR through PIK3R3、lncRNA E2F3-IT1.By inhibiting the secretion of androgen,a certain degree of autophagy inhibition can be relieved and abnormal secretion of sebum can be reduced.Part 2Objective:To investigate the potential effects of testosterone on autophagy and its potential involvement in lipid accumulation and sebocytes proliferation.Methods:Human sebocytes SZ95 were cultured and divided into four groups:control group,LA+T group,LA+T+Rapa group and LA+3-MA(autophagy inhibitor)group.Cells in the control group were treated with 100 nM LA;cells in the LA+T group were co-treated with 100 nM LA and 100 mM androgen;cells in the LA+T+Rapa group were treated with 100 nM LA and 100 mM androgen plus 1 mM rapamycin(Rapa);The cells of the LA+3-MA group were co-treated with 100 nM LA and 3-MA(5 mM).Sebaceous gland autophagy marker protein LC3-Ⅱ,autophagy degradation representative protein p62 level,cell lipid content,triglyceride(TG)level,cell proliferation activity(MTT and Ki67 immunofluorescence),AKT/mTOR signaling pathway were detected.Results:(1)compared with control,treatment with testosterone decreased the level of LC-3Ⅱ,while increased the level of p62 in SZ95 cells.Treatment with testosterone promoted the accumulation of lipid as visualized by Oil Red O staining and increased the content of TG in SZ95 cells simultaneously.Treatment with testosterone also increased the number of living SZ95 cells in MTT assay and the count of Ki67 positive cells in immuno fluorescent staining.The immunoblot analysis found that treatment with testosterone enhanced the phosphorylation of AKT and mTOR.(2)Treatment with 3-MA mimicked all the above effects of testosterone.(3)Co-treatment with testosterone and rapamycin reversed the effects of testosterone on autophagy,lipid accumulation,sebocytes proliferation and the phosphorylation of AKT and mTOR.Conclusion:testosterone might promote progression of acne via activation of mTOR and then repression of autophagy.