Pulmonary Vascular Remodeling Module

Module pulmonary_vascular_remodeling 9 disorders Pathograph 5

A conserved pulmonary vascular pathophysiology module representing the convergent mechanism by which heritable and idiopathic pulmonary arterial hypertension (PAH) and connective-tissue-disease-associated PAH produce sustained elevation of pulmonary arterial pressure. Pulmonary endothelial injury and dysfunction with impaired bone morphogenetic protein (BMP) signaling and an imbalance of vasodilators (nitric oxide, prostacyclin) versus vasoconstrictors (endothelin-1) triggers a pro-proliferative, anti-apoptotic switch in pulmonary artery smooth muscle cells. The resulting medial hypertrophy and intimal/plexiform lesions obstruct small pulmonary arteries, raising pulmonary vascular resistance and driving right ventricular pressure overload and failure. Although the initiating insult varies across heritable (BMPR2 mutation), idiopathic, and associated PAH, the downstream causal chain converges on this conserved remodeling sequence. Conforming disorder entries declare conformance via conforms_to on their pathophysiology nodes, substituting disorder-specific triggers and cell-type context while preserving the conserved chain.

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Pathophysiology Nodes

5 shared nodes are defined in this module.

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Cell Types

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Biological Processes

BMP signaling pathway GO:0030509 DECREASED nitric oxide biosynthetic process GO:0006809 DECREASED smooth muscle cell proliferation GO:0048659 INCREASED resistance to apoptosis GO:0043066 INCREASED vasoconstriction GO:0042310 INCREASED blood vessel remodeling GO:0001974 DYSREGULATED right ventricular hypertrophy GO:0003300 INCREASED

Notes

This is a mechanism module, not a specific disease. Disorder entries reference individual nodes via conforms_to (e.g., "pulmonary_vascular_remodeling#Obstructive Pulmonary Vascular Remodeling"). The module defines the expected pathophysiology structure; conforming nodes in disorder files should include the corresponding cell types, biological processes, and causal edges, specialized to their disease context. Key disorder-specific substitutions: heritable PAH substitutes a BMPR2 loss-of-function lesion at the trigger node; idiopathic PAH substitutes acquired endothelial injury; connective-tissue-disease-associated PAH (e.g., systemic sclerosis) substitutes immune/inflammatory endothelial injury. The pulmonary artery endothelial cell and pulmonary artery smooth muscle cell are the conserved central cell types.

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Used By Disorder Entries

Alveolar capillary dysplasia with misalignment of pulmonary veins via Increased Pulmonary Vascular Resistance , Severe Refractory Pulmonary Arterial Hypertension → Pulmonary Arterial Hypertension

Chuvash Polycythemia via Pulmonary Vascular Tone and Remodeling → Pulmonary Artery Smooth Muscle Cell Proliferation and Vasoconstriction

Congenital Diaphragmatic Hernia via Pulmonary Vascular Maldevelopment and Remodeling → Obstructive Pulmonary Vascular Remodeling , Persistent Pulmonary Hypertension of the Newborn → Pulmonary Arterial Hypertension

Eisenmenger Syndrome via Shear-stress-mediated pulmonary endothelial dysfunction → Pulmonary Endothelial Dysfunction and Impaired BMP Signaling , Pulmonary artery smooth muscle proliferation and vasoconstriction → Pulmonary Artery Smooth Muscle Cell Proliferation and Vasoconstriction , Obstructive pulmonary vascular remodeling → Obstructive Pulmonary Vascular Remodeling , Increased pulmonary vascular resistance → Increased Pulmonary Vascular Resistance , Pulmonary arterial hypertension with right ventricular pressure overload → Pulmonary Arterial Hypertension

Heritable Pulmonary Arterial Hypertension via Occlusive pulmonary vascular remodeling and increased resistance → Obstructive Pulmonary Vascular Remodeling

Idiopathic Pulmonary Arterial Hypertension via Pulmonary Arterial Endothelial Dysfunction → Pulmonary Endothelial Dysfunction and Impaired BMP Signaling , Pulmonary Artery Smooth Muscle Cell Proliferation and Vasoconstriction , Obstructive Pulmonary Vascular Remodeling , Increased Pulmonary Vascular Resistance , Precapillary Pulmonary Arterial Hypertension with Right Ventricular Failure → Pulmonary Arterial Hypertension

Persistent Truncus Arteriosus via Pulmonary vascular obstructive disease → Obstructive Pulmonary Vascular Remodeling

Rheumatic Heart Disease via Pulmonary venous congestion and pulmonary hypertension → Obstructive Pulmonary Vascular Remodeling

Ventricular Septal Defect via Obstructive Pulmonary Vascular Remodeling

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Pathograph

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Pathophysiology

Pulmonary Endothelial Dysfunction and Impaired BMP Signaling

trigger

The initiating lesion is injury to and dysfunction of pulmonary arterial endothelial cells, with impaired bone morphogenetic protein (BMP) signaling (loss-of-function BMPR2 mutations in heritable PAH, acquired suppression in idiopathic and associated PAH). Dysfunctional endothelium loses its ability to produce vasodilatory mediators such as nitric oxide and prostacyclin while favoring vasoconstrictors such as endothelin-1, and undergoes hyperproliferation with early apoptosis followed by enrichment of apoptosis-resistant cells. This endothelial trigger generalizes across heritable, idiopathic, and connective-tissue-disease-associated PAH.

pulmonary arterial endothelial cell CL:0000115

BMP signaling pathway GO:0030509 DECREASED nitric oxide biosynthetic process GO:0006809 DECREASED

Used by disorders

Eisenmenger Syndrome as Shear-stress-mediated pulmonary endothelial dysfunction

Idiopathic Pulmonary Arterial Hypertension as Pulmonary Arterial Endothelial Dysfunction

Downstream

Pulmonary Artery Smooth Muscle Cell Proliferation and Vasoconstriction

Pulmonary Artery Smooth Muscle Cell Proliferation and Vasoconstriction

amplifier

Paracrine signals from the dysfunctional endothelium drive a cancer-like pro-proliferative, anti-apoptotic switch in pulmonary artery smooth muscle cells (PASMCs), together with sustained vasoconstriction. PASMCs acquire migratory capacity and resistance to apoptosis, increasing medial cellularity. This amplifying step is conserved across PAH subtypes regardless of the specific initiating endothelial injury.

pulmonary artery smooth muscle cell CL:0000192

smooth muscle cell proliferation GO:0048659 INCREASED resistance to apoptosis GO:0043066 INCREASED vasoconstriction GO:0042310 INCREASED

Used by disorders

Chuvash Polycythemia as Pulmonary Vascular Tone and Remodeling

Eisenmenger Syndrome as Pulmonary artery smooth muscle proliferation and vasoconstriction

Idiopathic Pulmonary Arterial Hypertension

Downstream

Obstructive Pulmonary Vascular Remodeling

Obstructive Pulmonary Vascular Remodeling

central effector

Sustained PASMC proliferation, neointima formation, and endothelial dysregulation remodel the pulmonary arterial wall, producing medial and adventitial hypertrophy, muscularization of previously nonmuscular peripheral arteries, and intimal and plexiform lesions that obliterate the lumen of small pulmonary arteries. This structural obstruction is the central effector of the module and is conserved across PAH subtypes.

pulmonary artery smooth muscle cell CL:0000192

blood vessel remodeling GO:0001974 DYSREGULATED

Used by disorders

Congenital Diaphragmatic Hernia as Pulmonary Vascular Maldevelopment and Remodeling

Eisenmenger Syndrome as Obstructive pulmonary vascular remodeling

Heritable Pulmonary Arterial Hypertension as Occlusive pulmonary vascular remodeling and increased resistance

Idiopathic Pulmonary Arterial Hypertension

Persistent Truncus Arteriosus as Pulmonary vascular obstructive disease

Rheumatic Heart Disease as Pulmonary venous congestion and pulmonary hypertension

Ventricular Septal Defect

Downstream

Increased Pulmonary Vascular Resistance

Increased Pulmonary Vascular Resistance

effector

Structural obstruction and sustained vasoconstriction of the small pulmonary arteries increase pulmonary vascular resistance. The combination of dynamic (vasoconstrictive) and fixed (remodeling) obstruction raises the resistance the right ventricle must pump against.

Used by disorders

Alveolar capillary dysplasia with misalignment of pulmonary veins

Eisenmenger Syndrome as Increased pulmonary vascular resistance

Idiopathic Pulmonary Arterial Hypertension

Downstream

Pulmonary Arterial Hypertension

Pulmonary Arterial Hypertension

consequence

The convergent consequence is a sustained elevation of pulmonary arterial pressure. The increased resistance imposes a chronic pressure overload on the right ventricle, causing right ventricular hypertrophy and, in many patients, maladaptive remodeling that progresses to right ventricular failure and premature death. This is the named clinical phenotype (HP:0002092; MONDO:0005149).

right ventricular hypertrophy GO:0003300 INCREASED

Used by disorders

Alveolar capillary dysplasia with misalignment of pulmonary veins as Severe Refractory Pulmonary Arterial Hypertension

Congenital Diaphragmatic Hernia as Persistent Pulmonary Hypertension of the Newborn

Eisenmenger Syndrome as Pulmonary arterial hypertension with right ventricular pressure overload

Idiopathic Pulmonary Arterial Hypertension as Precapillary Pulmonary Arterial Hypertension with Right Ventricular Failure