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Transamniotic stem cell therapy (TRASCET) with mesenchymal stem cells (MSCs) has been shown to impact pulmonary vascular development and remodeling in experimental congenital diaphragmatic hernia (CDH), with secondary structural cardiac effects. We sought to determine whether TRASCET has any functional impact on term fetal pulmonary hemodynamics in the nitrofen model. Time-dated pregnant rat dams (n = 13) received nitrofen on gestational day 9 (E9) to induce fetal CDH. Fetuses (n = 155) were divided into three groups: untreated (n = 45), and two groups receiving volume-matched intra-amniotic injections on E17 of either saline (sham; n = 46), or a suspension of amniotic fluid-derived MSCs (afMSCs) (TRASCET; n = 64). Donor afMSCs were syngeneic, phenotyped by flow cytometry, and "primed" by exposure to interferon-gamma and interleukin-1beta prior to administration in vivo. At term (E21), fetuses underwent Doppler flow assessment at the mid-pulmonary artery and 4-chamber echocardiogram. Pulmonary vascular resistance was estimated by pulmonary artery acceleration time (PAAT), max velocity (MaxV) and velocity time integral (VTI). Cardiac function was assessed by global longitudinal strain (GLS) and ejection fraction (EF) using speckle analyses. Healthy fetuses (n = 11) served as additional controls. Statistical analysis was by the Mann-Whitney U test High resolution ultrasound data could be obtained from 8 to 13 fetuses per group. The PAAT and the PAAT normalized to cardiac cycle time were significantly improved by TRASCET compared to both untreated and sham-treated CDH (p = 0.004 to <0.001 in all pairwise comparisons). The flow profile sharpness (MaxV:VTI) was increased in untreated (p = 0.06) and sham (p = 0.01) groups but normalized by TRASCET (p <0.01). There was no difference in GLS between TRASCET and either the untreated or sham groups (p = 0.25 to p = 0.93). Transamniotic stem cell therapy improves pulmonary vascular resistance in early term fetuses in the Nitrofen model of congenital diaphragmatic hernia. Further focus on the functional pulmonary hemodynamic impact of this therapy is justified. N/A (animal and laboratory study) [ABSTRACT FROM AUTHOR]

Purpose: We examined select pulmonary effects and donor cell kinetics after transamniotic stem cell therapy (TRASCET) in a model of congenital diaphragmatic hernia (CDH). Methods: Pregnant dams (n = 58) received nitrofen on gestational day 9.5 (E9) to induce fetal CDH. Fetuses (n = 681) were divided into 4 groups: untreated (n = 99) and 3 groups receiving volume-matched intra-amniotic injections on E17 of either saline (n = 142), luciferase-labeled amniotic fluid-derived mesenchymal stem cells (afMSCs; n = 299), or acellular recombinant luciferase (n = 141). Pulmonary morphometry, quantitative gene expression of pulmonary vascular tone mediators, or screening for labeled afMSCs were performed at term (E22). Statistical comparisons were by Mann-Whitney U-test, nested ANOVA, and Wald test. Results: TRASCET led to significant downregulation of endothelial nitric oxide synthase and endothelin receptor-A expressions compared to both untreated and saline groups (both p < 0.001). TRASCET also led to a significant decrease in arteriole wall thickness compared to the untreated group (p < 0.001) but not the saline group (p = 0.180). Donor afMSCs were identified in the bone marrow and umbilical cord (p = 0.035 and 0.015, respectively, vs. plain luciferase controls). Conclusions: The effects of TRASCET in experimental CDH appear to be centered on the pulmonary vasculature and to derive from circulating donor cells. [ABSTRACT FROM AUTHOR]