Endothelial colony-forming cell therapy for heart morphological changes after neonatal high oxygen exposure in rats, a model of complications of prematurity

Very preterm birth is associated with increased cardiovascular diseases and changes in myocardial structure. The current study aimed to investigate the impact of endothelial colony-forming cell (ECFC) treatment on heart morphological changes in the experimental model of neonatal high oxygen (O2 )-induced cardiomyopathy, mimicking prematurity-related conditions. Sprague-Dawley rat pups exposed to 95% O2 or room air (RA) from day 4 (P4) to day 14 (P14) were randomized to receive (jugular vein) exogenous human cord blood ECFC or vehicle at P14 (n = 5 RA-vehicle, n = 8 RA-ECFC, n = 8 O2 -vehicle and n = 7 O2 -ECFC) and the hearts collected at P28. Body and heart weights and heart to body weight ratio did not differ between groups. ECFC treatment prevented the increase in cardiomyocyte surface area in both the left (LV) and right (RV) ventricles of the O2 group (O2 -ECFC vs. O2 -vehicle LV: 121 ± 13 vs. 179 ± 21 μm2 , RV: 118 ± 12 vs. 169 ± 21 μm2 ). In O2 rats, ECFC treatment was also associated with a significant reduction in interstitial fibrosis in both ventricles (O2 -ECFC vs. O2 -vehicle LV: 1.07 ± 0.47 vs. 1.68 ± 0.41% of surface area, RV: 1.01 ± 0.74 vs. 1.77 ± 0.67%) and in perivascular fibrosis in the LV (2.29 ± 0.47 vs. 3.85 ± 1.23%) but in not the RV (1.95 ± 0.95 vs. 2.74 ± 1.14), and with increased expression of angiogenesis marker CD31. ECFC treatment had no effect on cardiomyocyte surface area or on tissue fibrosis of RA rats. Human cord blood ECFC treatment prevented cardiomyocyte hypertrophy and myocardial and perivascular fibrosis observed after neonatal high O2 exposure. ECFC could constitute a new regenerative therapy against cardiac sequelae caused by deleterious conditions of prematurity.

Regular and moderate exercise before experimental sepsis reduces the risk of lung and distal organ injury

Physical activity modulates inflammation and immune response in both normal and pathologic conditions. We investigated whether regular and moderate exercise before the induction of experimental sepsis reduces the risk of lung and distal organ injury and survival. One hundred twenty-four BALB/c mice were randomly assigned to two groups: sedentary (S) and trained (T). Animals in T group ran on a motorized treadmill, at moderate intensity, 5% grade, 30 min/day, 3 times a week for 8 wk. Cardiac adaptation to exercise was evaluated using echocardiography. Systolic volume and left ventricular mass were increased in T compared with S group. Both T and S groups were further randomized either to sepsis induced by cecal ligation and puncture surgery (CLP) or sham operation (control). After 24 h, lung mechanics and histology, the degree of cell apoptosis in lung, heart, kidney, liver, and small intestine villi, and interleukin (IL)-6, KC (IL-8 murine functional homolog), IL-1β, IL-10, and number of cells in bronchoalveolar lavage (BALF) and peritoneal lavage (PLF) fluids as well as plasma were measured. In CLP, T compared with S groups showed: 1) improvement in survival; 2) reduced lung static elastance, alveolar collapse, collagen and elastic fiber content, number of neutrophils in BALF, PLF, and plasma, as well as lung and distal organ cell apoptosis; and 3) increased IL-10 in BALF and plasma, with reduced IL-6, KC, and IL-1β in PLF. In conclusion, regular and moderate exercise before the induction of sepsis reduced the risk of lung and distal organ damage, thus increasing survival.