Identification of Origin and Elucidation of Growth and Differetniation Mechanism of Satellite Cells in Human Urethral Rhabdosphincter

目的：尿道横纹括约肌是维持尿道功能最重要的组织，随着年龄的增长和前列腺手术的进行，尿道横纹括约肌的损伤和/或减少会导致压力性尿失禁。本研究旨在分离培养人尿道横纹括约肌卫星细胞，为阐明其生长分化机制和发展尿道横纹括约肌再生的新治疗模式提供实验依据。材料和方法：人尿道横纹括约肌取自行根治性膀胱或直肠癌根治性切除术的患者。将标本经胶原酶处理、培养后，用抗NCAM抗体标记微珠，采用MACS技术分离人尿道横纹括约肌卫星细胞。结果与结论：人尿道横纹括约肌卫星细胞在mRNA和蛋白水平上产生HGF和IGF-I，刺激其生长。HGF和IGF-I分别激活人尿道横纹括约肌卫星细胞MAPK和PI 3-K信号转导。本研究首次发现TNF-α以剂量依赖方式诱导人尿道横纹括约肌卫星细胞凋亡。TNF-α抑制剂可能对人尿道横纹肌具有保护作用，对老年人压力性尿失禁的治疗和预防具有重要意义。

Objective : Urethral rhabdosphincter is the most important tissue for preservation of urinary continence, and its injury and/or decrease due to aging and prostate surgery induced stress urinary incontinence. This study was performed to clarify and culture satellite cells in human urethral rhabdosphincter for the elucidation of growth and differentiation mechanism and development of new therapeutic modality for urethral rhabdosphincter regeneration.Materials and Method : Human urethral rhabdosphincter was obtained from patients who underwent radical prostatectomy or radical cystoprostatectomy. After the specimens were treated with collagenase and cultured, satellite cells in human urethral rhabdosphincter were isolated by MACS technique using anti-NCAM antibody conjugated with microbeads. Isolated satellite cells were confirmed as striated muscle origin by immunocytochemistry with anti-Myf-5 and anti-MyoD antibodies, and they were transfected with SV40 T antigen to obtain longevity.Results and Conclusion : Satellite cells of human urethral rhabdosphincter produced HGF and IGF-I at mRNA and protein levels, which stimulated their growth. HGF and IGF-I activated MAPK and PI3-K signal transduction in satellite cells of human urethral rhabdosphincter, respectively.Human urethral rhabdosphincter is reported to decrease due to apotosis with aging. In this study, TNF-α induced apoptosis by dose-dependent fashion in satellite cells of human urethral rhabdosphincter for the first time. Inhibitors of TNF-α may protect human urethral rhabdospincter from reduction with aging and be useful for the treatment and prevention of stress urinary incontinence in elderly.