Expression And Clinical Significance Of 5α-reductase Isoenzymes MRNA In Hair Follicles Of Male Androgenetic Alopecia

Objective:Hair specimens were obtained by minimally invasive extraction.The expression of type I-III 5α-reductase mRNA in hair follicles of male androgenetic alopecia and normal human hair was detected and its clinical significance was explored.Methods:The subjects were 63 male androgenetic alopecia patients and 30 healthy controls.Extraction of hair follicles with FUE and pulling hair to obtain follicle specimens,the total RNA in hair follicles was extracted and the mRNA expression of 5α-reductase isoenzyme(SRD5A1-3)was detected by polymerase chain reaction(PCR).All patients were given 1mg finasteride,1 times a day for 6 months.To analyse the mRNA expression of three isoenzymes and clinical efficacy,severity of hair loss,age of onset,family history of alopecia.Results:The expression of the three types of 5α-reductase was detected in the specimens obtained by the method of pulling hair and FUE taking hair follicles,and there was no significant difference between the specimens obtained by the two methods(P>0.05).The expression of SRD5A3 in hair follicles is higher than that of SRD5A1 and SRD5A2.There was a positive correlation between the three types of5α-reductase(P<0.05).There was no significant difference in scalp expression of three types of 5α-reductase in different parts of scalp and non-alopecia patients(P>0.05).The difference between the expression of SRD5A3 before and after drug administration was statistically significant(P<0.05),The expression level of SRD5A3 increased after administration.There was no significant correlation between the expression of 5α-reductase and clinical efficacy,alopecia severity,age at onset,and family history(P>0.05).Conclusions:Detection of 5α-reductase mRNA expression in hair follicles can obtain specimens by minimally invasive extraction.SRD5A3 is present in the inner and outer hair root sheaths of hair follicles,and the expression level is related to the expression of SRD5A1 and SRD5A2,and higher than the expression of SRD5A1 and SRD5A2.There was no significant difference in the expression of the three types of 5α-reductase at the edge of hair loss area and in occipital hair follicles.There was no significant difference in the expression of the three types of 5α-reductase in scalp hair follicles between androgenetic alopecia and non-alopecia patients.This suggests that the key to the pathogenesis of AGA is that the reactivity of androgen after hair papillae androgens binding to receptors,It is related to the activation of downstream pathways.No correlation was found between 5α-reductase mRNA expression and clinical efficacy,age of onset,and severity of disease.Further examination of the localization of type III 5α-reductase in different cells of hair follicles will help to further understand its role in the pathogenesis of AGA.