Department of Pathology and Human Anatomy, School of Medicine, Loma Linda University, Loma Linda, California, USA.
Biol Reprod. 2012 Nov 1;87(5):106. doi: 10.1095/biolreprod.112.101840. Print 2012 Nov.
Remodeling of the cervix is a critical early component of parturition and resembles an inflammatory process. Infiltration and activation of myeloid immune cells along with production of proinflammatory mediators and proteolytic enzymes are hypothesized to regulate cervical remodeling as pregnancy nears term. The present study standardized an approach to assess resident populations of immune cells and phenotypic markers of functional activities related to the mechanism of extracellular matrix degradation in the cervix in preparation for birth. Analysis of cells from the dispersed cervix of mice that were nonpregnant or pregnant (Days 15 and 18 postbreeding) by multicolor flow cytometry indicated increased total cell numbers with pregnancy as well as increased numbers of macrophages, the predominant myeloid cell, by Day 18, the day before birth. The number of activated macrophages involved in matrix metalloproteinase induction (CD147) and signaling for matrix adhesion (CD169) significantly increased by the day before birth. Expression of the adhesion markers CD54 and CD11b by macrophages decreased in the cervix by Day 18 versus that on Day 15 or in nonpregnant mice. The census of cells that expressed the migration marker CD62L was unaffected by pregnancy. The data suggest that remodeling of the cervix at term in mice is associated with recruitment and selective activation of macrophages that promote extracellular matrix degradation. Indices of immigration and activities by macrophages may thus serve as markers for local immune cell activity that is critical for ripening of the cervix in the final common mechanism for parturition at term.
子宫颈重塑是分娩的一个关键早期组成部分,类似于炎症过程。据推测,髓样免疫细胞的浸润和激活以及前炎性介质和蛋白水解酶的产生,可调节临近足月妊娠的子宫颈重塑。本研究标准化了一种评估免疫细胞常驻群体的方法,并评估了与细胞外基质降解机制相关的功能活性的表型标志物,为分娩做准备。通过多色流式细胞术分析非妊娠或妊娠(交配后第 15 和 18 天)小鼠离散子宫颈的细胞表明,随着妊娠的进行,总细胞数量增加,并且在分娩前一天(第 18 天),巨噬细胞(主要的髓样细胞)的数量增加。参与基质金属蛋白酶诱导(CD147)和基质黏附信号(CD169)的活化巨噬细胞的数量在分娩前一天显著增加。与第 15 天或非妊娠小鼠相比,第 18 天,巨噬细胞上的黏附标志物 CD54 和 CD11b 的表达在子宫颈中减少。表达迁移标志物 CD62L 的细胞计数不受妊娠影响。数据表明,妊娠足月时小鼠子宫颈重塑与募集和选择性激活促进细胞外基质降解的巨噬细胞有关。因此,巨噬细胞的移民和活性指数可以作为局部免疫细胞活性的标志物,对于足月分娩的最后共同机制即子宫颈成熟至关重要。