Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
Stem Cells Dev. 2020 Jun 15;29(12):755-760. doi: 10.1089/scd.2020.0012. Epub 2020 Apr 29.
Donor mesenchymal stem cells (MSCs) have been documented in fetal and maternal circulations after plain intra-amniotic injection, with diverse therapeutic effects. We sought to determine the pathway of this unique cell kinetic route. Rat fetuses ( = 226) were divided into two groups based on the content of intra-amniotic injections performed on gestational day 17 (E17): either a concentrated suspension of luciferase-labeled syngeneic amniotic fluid-derived MSCs (afMSCs; = 111), or acellular luciferase ( = 115). Samples from placenta, chorion, amnion, amniotic fluid, stomach fluid, peripheral blood, and umbilical cord were procured at five daily time points thereafter until term (E18-22) for luminometry. In addition, 53 sets of fresh gestational membranes (chorion/amnion combined) from nonmanipulated term fetuses were secured to transwell inserts for in vitro analysis of MSC migration using luciferase-labeled afMSCs. Statistical analyses included the Mann-Whitney -test, Wald test, nonlinear regression modeling, and Fisher's exact test. In vivo, luciferase activity was observed in the amnion, chorion, and placenta of fetuses receiving cells, but not in those receiving acellular luciferase ( < 0.001). There was a consistent nonlinear age-dependent relationship of luciferase activity between the amnion, chorion, and placenta following a parabolic bimodal pattern characterized by significantly higher early preterm (E18) and late-term (E22) activities ( < 0.001), with no differences between E21 and E22 ( = 0.12). In vitro, the presence of cells was documented by luminometry in 21/53 (39.6%) of the assays, in suspension and/or attached to the plastic substrate, and within all screened gestational membrane sets, irrespective of stimuli with collagen coating or fetal bovine serum. We conclude that, after intra-amniotic injection, donor MSCs undergo controlled cell routing, as opposed to passive clearance. Transgestational membrane transport appears to constitute the path for donor cells to reach the placenta, a known gateway to the fetal circulation, significantly expanding the potential applications of transamniotic stem cell therapy.
供体细胞（MSCs）在胎儿和母体循环中被记录下来，这些细胞来源于单纯的羊膜内注射，具有多种治疗效果。我们试图确定这种独特的细胞动力学途径的途径。根据在妊娠第 17 天（E17）进行的羊膜内注射的内容，将大鼠胎儿（n=226）分为两组：一组是浓缩的荧光素酶标记的同源羊水来源的 MSCs（afMSCs；n=111）的混悬液，另一组是无细胞的荧光素酶（n=115）。此后，在五个每日时间点从胎盘、绒毛膜、羊膜、羊水、胃液、外周血和脐带中采集样本，直至足月（E18-22）进行发光计检测。此外，从非操作的足月胎儿中采集了 53 组新鲜的妊娠膜（绒毛膜/羊膜联合），并将其固定在 transwell 插入物中，用于使用荧光素酶标记的 afMSCs 分析 MSC 迁移。统计分析包括 Mann-Whitney U 检验、Wald 检验、非线性回归建模和 Fisher 确切检验。在体内，接受细胞的胎儿的羊膜、绒毛膜和胎盘中观察到荧光素酶活性，但接受无细胞荧光素酶的胎儿中没有观察到（<0.001）。在一个抛物线双模态模式下，羊膜、绒毛膜和胎盘之间的荧光素酶活性呈一致的非线性年龄依赖性关系，其特征是早期早产（E18）和晚期（E22）活性显著升高（<0.001），E21 和 E22 之间没有差异（=0.12）。在体外，通过发光计在 53 个检测中的 21 个（39.6%）检测到细胞的存在，这些细胞以悬浮状态和/或附着在塑料基质上存在，并且在所有筛选的妊娠膜组中都存在，无论是否用胶原涂层或胎牛血清刺激。我们的结论是，在羊膜内注射后，供体 MSCs 经历了受控的细胞路由，而不是被动清除。跨胎盘膜转运似乎是供体细胞到达胎盘的途径，胎盘是胎儿循环的已知门户，这显著扩大了经羊膜干细胞治疗的潜在应用。
