August 7, 2026Journal of the American College of Cardiology1,567 citationsOpen Access
Cellular and molecular pathobiology of pulmonary arterial hypertension
Key Result
Pulmonary arterial hypertension is driven by a multifactorial pathobiology involving vasoconstriction, vascular remodeling, and thrombosis mediated by endothelial dysfunction and various molecular targets.
Key Points
- To investigate the cellular and molecular mechanisms underlying pulmonary arterial hypertension (PAH).
- Analysis of cellular types involved in PAH including endothelial cells, smooth muscle cells, and fibroblasts.
- Evaluation of vascular remodeling and its association with dysfunction of potassium channels and endothelial cells.
- Genetic and pathophysiological studies focusing on mediators such as nitric oxide, prostacyclin, and endothelin.
- Vasoconstriction and enhanced vascular resistance are early components in the development of PAH.
- Endothelial dysfunction correlates with reduced vasodilator production and increased levels of vasoconstrictors such as ET-1.
- Several mediators, including cytokines and members of the transforming-growth-factor-beta superfamily, are implicated in the pathobiology of PAH.
PICO
P
Population
Pulmonary arterial hypertension
Abstract
Pulmonary arterial hypertension (PAH) has a multifactorial pathobiology. Vasoconstriction, remodeling of the pulmonary vessel wall, and thrombosis contribute to increased pulmonary vascular resistance in PAH. The process of pulmonary vascular remodeling involves all layers of the vessel wall and is complicated by cellular heterogeneity within each compartment of the pulmonary arterial wall. Indeed, each cell type (endothelial, smooth muscle, and fibroblast), as well as inflammatory cells and platelets, may play a significant role in PAH. Pulmonary vasoconstriction is believed to be an early component of the pulmonary hypertensive process. Excessive vasoconstriction has been related to abnormal function or expression of potassium channels and to endothelial dysfunction. Endothelial dysfunction leads to chronically impaired production of vasodilators such as nitric oxide and prostacyclin along with overexpression of vasoconstrictors such as endothelin (ET)-1. Many of these abnormalities not only elevate vascular tone and promote vascular remodeling but also represent logical pharmacological targets. Recent genetic and pathophysiologic studies have emphasized the relevance of several mediators in this condition, including prostacyclin, nitric oxide, ET-1, angiopoietin-1, serotonin, cytokines, chemokines, and members of the transforming-growth-factor-beta superfamily. Disordered proteolysis of the extracellular matrix is also evident in PAH. Future studies are required to find which if any of these abnormalities initiates PAH and which ones are best targeted to cure the disease.