Pulmonary hypertension (PH) affects 16–25% of premature infants with bronchopulmonary dysplasia (BPD), contributing significantly to perinatal morbidity and mortality. Inflammation is highly implicated in the pathogenesis of PH and BPD. Polyunsaturated fatty acids ω-3 (PUFA ω-3) can improve vascular remodeling, angiogenesis, and inflammation under pathophysiological conditions. However, the effects of PUFA ω-3 supplementation in BPD-associated PH are unknown.

Evaluate the effects of PUFA ω-3 on pulmonary vascular remodeling, angiogenesis, and inflammatory response in a hyperoxia-induced rat model of PH.

From embryonic day 15, pregnant Spague-Dawley rats were supplemented daily with PUFA ω-3, PUFA ω-6, or normal saline (0.2ml/day). After birth, pups were pooled, assigned as 12 per litter, and randomly to either in air or continuous oxygen exposure (FiO₂₌85%) for 20 days, then sacrificed for pulmonary hemodynamic, morphometric, and immunohistological analysis.

PUFA ω-3 supplementation improved survival, decreased right ventricular systolic pressure and RVH caused by hyperoxia, and significantly improved alveolarization, vascular remodeling, and vascular density. PUFA ω-3 supplementation produced a higher level of total ω-3 in lung tissue and breast milk, and was found reversing the reduced levels of VEGFA, VEGFR-2, ANGPT-1, TIE-2, eNOS, and no concentrations in lung tissue, and the increased ANGPT-2 levels in hyperoxia-exposed rats. The beneficial effects of PUFA ω-3 in improving lung injuries were also associated with an inhibition of leukocyte infiltration, and reduced expression of proinflammatory cytokines IL-1β, IL-6 and TNF-α.

These data indicated that maternal PUFA ω-3 supplementation strategies could effectively protect against infant PH induced by hyperoxia.