Pulmonary artery endothelial cell dysfunction and decreased populations of highly proliferative endothelial cells in experimental congenital diaphragmatic hernia

Abstract

Decreased lung vascular growth and pulmonary hypertension contribute to poor outcomes in congenital diaphragmatic hernia (CDH). Mechanisms that impair angiogenesis in CDH are poorly understood. We hypothesize that decreased vessel growth in CDH is caused by pulmonary artery endothelial cell (PAEC) dysfunction with loss of a highly proliferative population of PAECs (HP-PAEC). PAECs were harvested from near-term fetal sheep that underwent surgical disruption of the diaphragm at 60-70 days gestational age. Highly proliferative potential was measured via single cell assay. PAEC function was assessed by assays of growth and tube formation and response to known proangiogenic stimuli, vascular endothelial growth factor (VEGF), and nitric oxide (NO). Western blot analysis was used to measure content of angiogenic proteins, and superoxide production was assessed. By single cell assay, the proportion of HP-PAEC with growth of >1,000 cells was markedly reduced in the CDH PAEC, from 29% (controls) to 1% (CDH) (P < 0.0001). Compared with controls, CDH PAEC growth and tube formation were decreased by 31% (P = 0.012) and 54% (P < 0.001), respectively. VEGF and NO treatments increased CDH PAEC growth and tube formation. VEGF and VEGF-R2 proteins were increased in CDH PAEC; however, eNOS and extracellular superoxide dismutase proteins were decreased by 29 and 88%, respectively. We conclude that surgically induced CDH in fetal sheep causes endothelial dysfunction and marked reduction of the HP-PAEC population. We speculate that this CDH PAEC phenotype contributes to impaired vascular growth in CDH.

Effect of corticosteroids and lung ventilation in the VEGF and NO pathways in congenital diaphragmatic hernia in rats

“…With this increase in the expression of NOS3 there has been an increase in the production of nitric oxide, which is the main vasodilator of the cardiovascular system. According to most studies, the expression and the activity of eNOS are reduced in fetuses with CDH, when compared to controls [30][31][32][33]. Then, dexamethasone stimulates the production of NO generating a thinner arteriolar media layer that may decrease pulmonary hypertension.…”

Perturbations in Endothelial Dysfunction-Associated Pathways in the Nitrofen-Induced Congenital Diaphragmatic Hernia Model

“…The C-reactive protein (CRP) level is a well-known risk factor for vascular disease and endothelial dysfunction which are characterized by the decreased production of vasodilators and the increased production of vasoconstriction mediators [14,15,16]. It has been reported that PA EC dysfunction contributes to the development, progression, and severity of CDH-PH in experimental models [17], indicating that endothelial dysfunction-associated proteins may play an important role in the fundamental pathogenesis of CDH.…”

Histologic Identification of Prominent Intrapulmonary Anastomotic Vessels in Severe Congenital Diaphragmatic Hernia

“…Abnormal pulmonary blood flow and endothelial signaling are known to impair lung growth and alveolarization (32). Pulmonary artery endothelial cells have impaired growth and angiogenic capacity in an experimental model of CDH (33). However, mechanisms that disrupt coordinated growth of the distal lung and vasculature and contribute to prominent IPAV in CDH are not clear.…”