Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut, USA.
Biol Reprod. 2019 May 1;100(5):1228-1237. doi: 10.1093/biolre/ioy265.
Angiogenesis is essential for cyclic endometrial growth, implantation, and pregnancy maintenance. Vasculogenesis, the formation of new blood vessels by bone marrow (BM)-derived endothelial progenitor cells (EPCs), has been shown to contribute to endometrial vasculature. However, it is unknown whether vasculogenesis occurs in neovascularization of the decidua during pregnancy. To investigate the contribution of BM-derived EPCs to vascularization of the pregnant uterus, we induced non-gonadotoxic submyeloablation by 5-fluorouracil administration to wild-type FVB/N female mice recipients followed by BM transplantation from transgenic mice expressing green fluorescent protein (GFP) under regulation of Tie2 endothelial-specific promoter. Following 1 month, Tie2-GFP BM-transplanted mice were bred and sacrificed at various gestational days (ED6.5, ED10.5, ED13.5, ED18.5, and postpartum). Bone-marrow-transplanted non-pregnant and saline-injected pregnant mice served as controls (n = 5-6/group). Implantation sites were analyzed by flow cytometry, immunohistochemistry, and immunofluorescence. While no GFP-positive EPCs were found in non-pregnant or early pregnant uteri of BM-transplanted mice, GFP-positive EPCs were first detected in pregnant uterus on ED10.5 (0.12%) and increased as the pregnancy progressed (1.14% on ED13.5), peaking on ED18.5 (1.42%) followed by decrease in the postpartum (0.9%). The percentage of endothelial cells that were BM-derived out of the total endothelial cell population in the implantation sites (GFP+CD31+/CD31+) were 9.3%, 15.8%, and 6.1% on ED13.5, ED18.5, and postpartum, respectively. Immunohistochemistry demonstrated that EPCs incorporated into decidual vasculature, and immunofluorescence showed that GFP-positive EPCs colocalized with CD31 in vascular endothelium of uterine implantation sites, confirming their endothelial lineage. Our findings indicate that BM-derived EPCs contribute to vasculogenesis of the pregnant mouse decidua.
血管生成对于周期性子宫内膜生长、着床和妊娠维持至关重要。血管发生是指骨髓（BM）衍生的内皮祖细胞（EPC）形成新血管，已被证明有助于子宫内膜血管生成。然而，尚不清楚在妊娠期间蜕膜的新血管生成中是否发生血管发生。为了研究 BM 衍生的 EPC 对妊娠子宫血管生成的贡献，我们通过 5-氟尿嘧啶给药诱导非性腺毒性亚骨髓抑制，然后将来自表达绿色荧光蛋白（GFP）的转基因小鼠的 BM 移植到接受者中，GFP 的表达受 Tie2 内皮特异性启动子调控。1 个月后，Tie2-GFP BM 移植小鼠繁殖并在不同妊娠天数（ED6.5、ED10.5、ED13.5、ED18.5 和产后）处死。骨髓移植的未怀孕和盐水注射的怀孕小鼠作为对照（每组 n=5-6）。通过流式细胞术、免疫组织化学和免疫荧光分析着床部位。虽然在 BM 移植小鼠的未怀孕或早期怀孕子宫中未发现 GFP 阳性 EPC，但在怀孕第 10.5 天（0.12%）首次检测到 GFP 阳性 EPC，并随着妊娠的进展而增加（第 13.5 天为 1.14%），在第 18.5 天达到峰值（1.42%），随后在产后（0.9%）下降。在着床部位的总内皮细胞群体中，BM 衍生的内皮细胞的百分比（GFP+CD31+/CD31+）分别为 13.5 天的 9.3%、18.5 天的 15.8%和产后的 6.1%。免疫组织化学显示 EPC 整合到蜕膜血管中，免疫荧光显示 GFP 阳性 EPC 与子宫着床部位血管内皮中的 CD31 共定位，证实了它们的内皮谱系。我们的研究结果表明，BM 衍生的 EPC 有助于妊娠小鼠蜕膜的血管发生。
