Endothelial-to-Mesenchymal Transition in Human and Murine Models of Congenital Diaphragmatic Hernia

Neonatology. 2024;121(4):512-518. doi: 10.1159/000537802. Epub 2024 Apr 8.

Abstract

Introduction: Congenital diaphragmatic hernia (CDH) is a complex congenital disorder, characterized by pulmonary hypertension (PH) and hypoplasia. PH secondary to CDH (CDH-PH) features devastating morbidity and mortality (25-30%) among neonates. An unmet need is determining mechanisms triggering CDH-PH to save infants. Prior data suggest abnormal remodeling of the pulmonary vascular extracellular matrix (ECM), presumed to be driven by endothelial-to-mesenchymal transition (EndoMT), hinders postnatal vasodilation and limits anti-PH therapy in CDH. There are limited data on the role of EndoMT in CDH-PH.

Methods: The purpose of the study was to investigate how EndoMT contributes to CDH-PH by identifying cells undergoing EndoMT noted by alpha smooth muscle actin (α-SMA) expression in human umbilical vein endothelial cells (HUVECs) and lung tissue obtained from murine pups using the nitrofen model. N = 8 CDH, N = 8 control HUVECs were stained for α-SMA and CD31 after being exposed for 24 h to TGFB, a known EndoMT promoter. N = 8 nitrofen, N = 8 control murine pup lungs were also stained for α-SMA and CD31. α-SMA and CD31 expression was quantified in HUVECs and murine tissue using Fiji imaging software and normalized to the total number of cells per slide noted by DAPI staining.

Results: CDH HUVECs demonstrated a 1.1-fold increase in α-SMA expression (p = 0.02). The murine model did not show statistical significance between nitrofen and control pup lungs; however, there was a 0.4-fold increase in α-SMA expression with a 0.8-fold decrease in CD31 expression in the nitrofen pup lungs when compared to controls.

Conclusion: These results suggest that EndoMT could potentially play a role in the ECM remodeling seen in CDH-PH.

Keywords: Alpha smooth muscle actin; CD31; Congenital diaphragmatic hernia; Endothelial-to-mesenchymal transition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins* / genetics
  • Actins* / metabolism
  • Animals
  • Animals, Newborn
  • Disease Models, Animal*
  • Epithelial-Mesenchymal Transition
  • Hernias, Diaphragmatic, Congenital* / genetics
  • Hernias, Diaphragmatic, Congenital* / metabolism
  • Hernias, Diaphragmatic, Congenital* / pathology
  • Human Umbilical Vein Endothelial Cells* / metabolism
  • Humans
  • Hypertension, Pulmonary / etiology
  • Hypertension, Pulmonary / metabolism
  • Hypertension, Pulmonary / pathology
  • Lung* / metabolism
  • Lung* / pathology
  • Mice
  • Phenyl Ethers*
  • Platelet Endothelial Cell Adhesion Molecule-1 / genetics
  • Platelet Endothelial Cell Adhesion Molecule-1 / metabolism
  • Transforming Growth Factor beta / metabolism

Substances

  • Actins
  • Phenyl Ethers
  • Platelet Endothelial Cell Adhesion Molecule-1
  • nitrofen
  • ACTA2 protein, human
  • Transforming Growth Factor beta
  • Pecam1 protein, mouse