摘要
背景:Hedgehog信号通路对于多种组织的发育、动态平衡以及修复起了重要的作用,前人的研究强调了Hedgehog信号对于毛发模式形成是至关重要的。目的:探究Hedgehog信号在成年后的毛囊上皮动态平衡中发挥的作用。方法:Lgr5-EGFP-Ires-Cre ERT2小鼠、Smofl/fl小鼠与K14-CreER小鼠均来自TheJacksonLaboratory,实验经上海交通大学实验动物伦理与使用委员会批准,批准号为1602028。①首先利用Lgr5-EGFP-Ires-Cre ERT2小鼠特异地标记Lgr5+细胞亚群,确认了在Lgr5+毛囊上皮干细胞/前体细胞中多个Hedgehog信号通路成员高度富集表达。而后用Lgr5-EGFP-Ires-CreERT2小鼠与Smofl/fl小鼠交配得到了Lgr5-EGFP-Ires-CreERT2;Smofl/fl小鼠;在刚进入第二轮长静息期的P49天进行背部剃毛,接着用他莫昔芬诱导Hedgehog信号通路的介导蛋白Smo敲除,观察在Lgr5+细胞中敲除Smo对毛发再生速度的影响;之后实验在P50-54天他莫昔芬诱导Smo敲除后1周进行脱毛,进一步评估bulge上皮干细胞在突变小鼠的功能是否有变化;②用K14-Cre ER小鼠与Smofl/fl小鼠交配以得到K14-CreER;Smofl/fl小鼠,同上实验方法,在毛囊整个上皮细胞这一更大范围内用他莫昔芬诱导敲除Smo,观察是否有毛发再生障碍及毛囊Bulge干细胞功能障碍。结果与结论:Lgr5-EGFP-Ires-Cre ERT2;Smofl/fl小鼠模型及K14-CreER;Smofl/fl小鼠模型中均没有观测到明显的毛发再生障碍,毛囊Bulge干细胞也没有受到影响。说明Lgr5+细胞群和整个毛囊上皮对于Hedgehog信号通路的响应与毛囊静息期向生长期转换以及短期的毛发再生无关,且与bulge上皮干细胞的维持也无关。这一发现强调了组织发育和动态平衡之间的不同分子机制,为人们更加准确地理解毛囊再生和组织生长的机制提供了重要依据。
BACKGROUND: Hedgehog signaling plays a vital role in development, homeostasis and tissue repair of multiple tissues. Previous studies underscore that Hedgehog signaling is essential for hair morphogenesis.OBJECTIVE: To explore the role of Hedgehog signaling in adult epidermal homeostasis.METHODS: Lgr5-EGFP-Ires-CreERT2, Smofl/fl and K14-Cre ER mice were purchased from The Jackson Laboratory. This study was approved by the Laboratory Animal Ethics and Use Committee of Shanghai Jiao Tong University with the approval No. 1602028. First,Lgr5-EGFP-Ires-CreERT2 mice were used to specifically label Lgr5+ cell subsets, confirming several Hedgehog signaling components were enriched in Lgr5+ hair follicle epidermal stem cells/precursor cells. Lgr5-EGFP-Ires-CreERT2 mice then copulated with Smofl/fl mice.Lgr5-EGFP-Ires-CreERT2;Smofl/fl mice were obtained and shaved of their fur at P49 days of the second telogen period, followed by tamoxifen-induced Hedgehog signaling pathway-mediated Smo knockout. We observed the effect of Smo knockout on hair regeneration rate in Lgr5+ cells. In the following experiments, tamoxifen was used to induce Smo knockout on P50-54 days, and the mice were shaved of their fur the mice at 1 week after Smo knockout. We further evaluated the functional changes of bulge epithelial stem cells in mutant mice.(2)K14-Cre ER mice copulated with Smofl/fl to produce K14-Cre ER;Smofl/fl mice. Tamoxifen, as described above, was used to delete Smo in hair follicle epithelial basal cells. We observed whether hair loss disorder and hair follicle Bulge stem cell dysfunction occur.RESULTS AND CONCLUSION: No hair loss disorder was detected in Lgr5-EGFP-Ires-CreERT2;Smofl/fl and K14-CreER;Smofl/fl mouse models, and hair follicle Bulge stem cells were not affected. It is indicated that the responsiveness to Hedgehog signaling in Lgr5+ cells and hair follicle epithelial cells is independent of hair follicle telogen-to-anagen transition and short-term hair regeneration as well as the maintenance of Bulge epithelial stem c
作者
应沁心
陶一昕
杨青春
凌学剑
马钢
Ying Qinxin;Tao Yixin;Yang Qingchun;Ling Xuejian;Ma Gang(Bio-X Institutes, Key Laboratory for Genetics of Developmental andNeuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China)
出处
《中国组织工程研究》
CAS
北大核心
2019年第25期4044-4049,共6页
Chinese Journal of Tissue Engineering Research
基金
国家自然科学基金(31671504),项目负责人:马钢
上海交通大学医工交叉项目(YG2016MS04),项目参与人:马钢~~
