3-甲基腺嘌呤通过抑制自噬促进小鼠毛囊再生的作用研究

为研究自噬在毛囊周期循环和休止期脱发中的作用，以及是否可通过调节毛囊上皮细胞的自噬促进休止期毛囊的再生，采用拔毛法诱导3~4周龄C57BL/6小鼠的毛囊生长期，给予腹腔注射自噬抑制剂3-甲基腺嘌呤(3-methyladenine，3-MA)处理，并以空白和自噬诱导剂雷帕霉素(rapamycin，RAPA)为对照，结果发现，经3-MA处理后的毛囊再生明显加快，且新生毛发的数量与质量均明显优于Vehicle组和RAPA组。取处理后的小鼠皮肤组织经HE染色、Western blot、免疫组化和免疫荧光检测，发现经3-MA处理后，毛囊上皮细胞中的Beclin1表达、LC3BⅡ/Ⅰ比值均显著降低，P62和Ki67表达增加，同时以CD34、CD49f为双标记的毛囊干细胞的数目明显增多；但经RAPA处理后的毛囊中Beclin1表达、LC3BⅡ/Ⅰ比值明显增加，但P62和Ki67表达下降，且毛囊干细胞的数目减少。实验结果表明，通过3-MA抑制毛囊上皮细胞的自噬可以促进由拔毛法诱导的C57BL/6小鼠的毛发再生。3-MA或其他相关的自噬抑制剂可能在未来的人类休止期脱发的治疗中发挥重要作用。

Hair regeneration in mice was promoted by 3-methyladenine through inhibiting autophagy flux

To explore the role of autophagy in hair follicle cycle and whether 3-methyladenine(3-MA)could promote hair regeneration in C57BL/6 mice through inhibiting autophagy flux, hair regeneration model of C57BL/6 mice was induced on the dorsal skin by depilation, and 3-MA was intraperitoneally injected to investigate hair regrowth, meanwhile vehicle and rapamycin(RAPA)were used as the controls. Results showed that 3-MA could obviously promote hair regrowth in depilated C57BL/6 mice. Furtherly, haematoxylin-eosin staining, immunohistochemical staining, immunofluorescence and Western blot tests were used to investigate the autophagy signals and the cell proliferation. Results showed that the expression of Beclin1 and LC3B II/I ratio were significantly decreased. Expression of P62 and Ki67 were increased, as well as the CD34 and CD49f double-labeled hair follicle stem cells were obviously increased inside bulge areas in 3-MA group, while contrarily in RAPA group. These results affirmed 3-MA, an autophagy inhibitor, could promote hair regeneration in depilated C57BL/6 mice by facilitating the transformation of hair follicle from telogen to anagen. 3-MA and other analogous autophagy inhibitors probably have a potential usage in future therapy in human telogen effluvium diseases.