Morphometric, Developmental, and Anti-Inflammatory Effects of Transamniotic Stem Cell Therapy (TRASCET) on the Fetal Heart and Lungs in a Model of Intrauterine Growth Restriction.

Transamniotic stem cell therapy (TRASCET) with mesenchymal stem cells (MSCs) can attenuate placental inflammation and minimize intrauterine growth restriction (IUGR). We sought to determine whether MSC-based TRASCET could mitigate fetal cardiopulmonary effects of IUGR. Pregnant Sprague-Dawley dams were exposed to alternating 12-h hypoxia (10.5% O₂) cycles in the last fourth of gestation. Their fetuses (n = 155) were divided into 4 groups. One group remained untreated (n = 42), while three groups received volume-matched intra-amniotic injections of either saline (sham; n = 34), or of syngeneic amniotic fluid-derived MSCs, either in their native state (TRASCET; n = 36) or "primed" by exposure to interferon-gamma and interleukin-1beta before administration in vivo (TRASCET-primed; n = 43). Normal fetuses served as additional controls (n = 30). Multiple morphometric and biochemical analyses were performed at term for select markers of cardiopulmonary development and inflammation previously shown to be affected by IUGR. Among survivors (75%; 117/155), fetal heart-to-body weight ratio was increased in both the sham and untreated groups (P < 0.001 for both) but normalized in the TRASCET and TRASCET-primed groups (P = 0.275, 0.069, respectively). Cardiac b-type natriuretic peptide levels were increased in all hypoxia groups compared with normal (P < 0.001), but significantly decreased from sham and untreated in both TRASCET groups (P < 0.0001-0.005). Heart tumor necrosis factor-alpha levels were significantly elevated in sham and TRASCET groups (P = 0.009, 0.002), but normalized in the untreated and TRASCET-primed groups (P = 0.256, 0.456). Lung transforming growth factor-beta levels were significantly increased in both sham and untreated groups (P < 0.001, 0.003), but normalized in both TRASCET groups (P = 0.567, 0.303). Similarly, lung endothelin-1 levels were elevated in sham and untreated groups (P < 0.001 for both), but normalized in both TRASCET groups (P = 0.367, 0.928). We conclude that TRASCET with MSCs decreases markers of fetal cardiac strain, insufficiency, and inflammation, as well as of pulmonary fibrosis and hypertension in the rodent model of IUGR.