Szotek Paul P, Chang Henry L, Zhang LiHua, Preffer Frederic, Dombkowski David, Donahoe Patricia K, Teixeira Jose
Pediatric Surgical Research Laboratories, Department of Surgery, Massachusetts General Hospital, Boston, MA 02114, USA.
Stem Cells. 2007 May;25(5):1317-25. doi: 10.1634/stemcells.2006-0204. Epub 2007 Feb 8.
Conditional deletion of beta-catenin in the Müllerian duct mesenchyme results in a degenerative uterus characterized by replacement of the myometrial smooth muscle with adipose tissue. We hypothesized that the mouse myometrium houses somatic smooth muscle progenitor cells that are hormonally responsive and necessary for remodeling and regeneration during estrous cycling and pregnancy. We surmise that the phenotype observed in beta-catenin conditionally deleted mice is the result of dysregulation of these progenitor cells. The objective of this study was to identify the mouse myometrial smooth muscle progenitor cell and its niche, define the surface marker phenotype, and show a functional response of these cells to normal myometrial cycling. Uteri were labeled with 5-bromo-2'-deoxyuridine (BrdU) and chased for up to 14 weeks. Myometrial label-retaining cells (LRCs) were observed in the myometrium and stroma throughout the chase period. After 12 weeks, phenotypic analysis of the LRCs by immunofluorescence demonstrated that the majority of LRCs colocalized with alpha-smooth muscle actin, estrogen receptor-alpha, and beta-catenin. Flow cytometry of myometrial cells identified a myometrial Hoechst 33342 effluxing "side population" that expresses MISRII-Cre-driven YFP. Functional response of LRCs was investigated by human chorionic gonadotropin stimulation of week 12 chase mice and demonstrated sequential proliferation of LRCs in the endometrial stroma, followed by the myometrium. These results suggest that conventional myometrial regeneration and repair is executed by hormonally responsive stem or progenitor cells derived from the Müllerian duct mesenchyme. Disclosure of potential conflicts of interest is found at the end of this article.
缪勒管间充质中β-连环蛋白的条件性缺失导致子宫退化，其特征是子宫肌层平滑肌被脂肪组织取代。我们假设小鼠子宫肌层存在体细胞平滑肌祖细胞，这些细胞对激素有反应，并且在发情周期和妊娠期间的重塑和再生过程中是必需的。我们推测在β-连环蛋白条件性缺失小鼠中观察到的表型是这些祖细胞失调的结果。本研究的目的是鉴定小鼠子宫肌层平滑肌祖细胞及其微环境，确定表面标志物表型，并展示这些细胞对正常子宫肌层周期的功能反应。用5-溴-2'-脱氧尿苷（BrdU）标记子宫，并追踪长达14周。在整个追踪期内，在子宫肌层和基质中观察到子宫肌层标记保留细胞（LRCs）。12周后，通过免疫荧光对LRCs进行表型分析，结果表明大多数LRCs与α-平滑肌肌动蛋白、雌激素受体-α和β-连环蛋白共定位。子宫肌层细胞的流式细胞术鉴定出一个子宫肌层Hoechst 33342流出“侧群”，其表达MISRII-Cre驱动的YFP。通过人绒毛膜促性腺激素刺激第12周追踪的小鼠来研究LRCs的功能反应，结果表明LRCs在子宫内膜基质中依次增殖，随后在子宫肌层中增殖。这些结果表明，传统的子宫肌层再生和修复是由源自缪勒管间充质的对激素有反应的干细胞或祖细胞执行的。潜在利益冲突的披露见本文末尾。
