Furthermore, the recent finding that mutations in BMPR2 cause familial forms of pulmonary arterial hypertension and that BMPR2 expression is decreased in secondary forms of PH strongly implicate BMP signaling in the underlying pathophysiology of PH.
GCN2 expression was quantified by Western blotting in 24 PVOD patients, 44 patients with pulmonary arterial hypertension (PAH; 23 bone morphogenetic protein receptor type II [BMPR2] mutation carriers, 21 non-carriers), and 3 experimental pulmonary hypertension models.
Gene delivery of BMPR2 has now been shown to ameliorate the development and progression of PAH in animal models, thereby identifying this approach as a therapeutic target.
Here we show that the receptor BMP type 2 (BMPR2) serves as a central gatekeeper of this balance, highlighted by its deregulation in diseases such as pulmonary arterial hypertension (PAH).
Here, we examined the miRNA and proteomic profiles of blood outgrowth endothelial cells (BOECs) from patients with heritable PAH caused by mutations in the bone morphogenetic protein receptor type 2 (<i>BMPR2</i>) gene and patients with idiopathic PAH to determine mechanisms underlying abnormal endothelial glycolysis.
Heritable and idiopathic pulmonary arterial hypertension (PAH) are phenotypically identical and associated with mutations in several genes related to transforming growth factor (TGF) beta signaling, including bone morphogenetic protein receptor type 2, activin receptor-like kinase 1, endoglin, and mothers against decapentaplegic 9.
Heritable pulmonary arterial hypertension (PAH) is one such disorder characterised by rare mutations mostly occurring in the bone morphogenetic protein receptor type 2 (<i>BMPR2</i>) gene and a wide heterogeneity of penetrance modifier mechanisms.
Heterozygous mutations in BMPR2, encoding the type II bone morphogenetic protein receptor (BMPRII), were identified in PAH, suggesting that alterations to BMPRII function are involved in disease onset and/or progression.
Heterozygous mutations in the gene encoding the bone morphogenetic protein receptor type II (BMPR2) have been identified in both familial (FPAH) and idiopathic PAH.
Heterozygous mutations in the gene encoding the bone morphogenetic protein receptor type 2 (<i>BMPR2</i>) are the commonest genetic cause of PAH, whereas biallelic mutations in the eukaryotic translation initiation factor 2 alpha kinase 4 gene (<i>EIF2AK4</i>) are described in pulmonary veno-occlusive disease/pulmonary capillary hemangiomatosis.
Heterozygous null bone morphogenetic protein receptor type 2 mutations promote SRC kinase-dependent caveolar trafficking defects and endothelial dysfunction in pulmonary arterial hypertension.
However, current guidelines, clinical practices, and available gene panels focus the diagnosis of PAH on a relatively low number of genes and variants associated with the bone morphogenic proteins and transforming Growth Factor-β pathways, such as the BMPR2, ACVRL1, CAV1, ENG, and SMAD9.
However, despite the fact that most PAH families are consistent with linkage to the BMPR2 locus, sequencing only identifies mutations in some 55% of familial cases and between 10% and 40% of cases without a family history (idiopathic or IPAH).
However, less than one-half of BMPR2 mutation carriers develop PAH, suggesting that the most important function of BMPR2 mutation is to cause susceptibility to a "second hit."
However, only a small subset of individuals with <i>BMPR2</i> mutation develops PAH, suggesting that additional modifiers of BMPR2 function play an important role in the onset and progression of PAH.
HPAEC made dysfunctional by siRNA-mediated BMPR2 depletion showed downregulation of 18 and upregulation of 19 P2 receptor Ca<sup>2+</sup> signalosome genes including PLCD4, which was found to be upregulated in iPSC-EC from BMPR2-mutant patients with pulmonary arterial hypertension.
Hyperoxia, despite its vasodilatory actions in the pulmonary circulation, significantly worsened the PAH phenotype (elevated right ventricular systolic pressure, decreased cardiac output, and increased pulmonary vascular occlusion) in Bmpr2 mutant animals.
Idiopathic pulmonary arterial hypertension (IPAH) is usually without an identified genetic cause, despite clinical and molecular similarity to bone morphogenetic protein receptor type 2 mutation-associated heritable pulmonary arterial hypertension (PAH).
In addition, collaborative studies of BMPR2 mutation carriers should enable identification of environmental modifiers, biomarkers for disease development and progression, and surrogate markers for efficacy end points in clinical drug development, thereby providing an invaluable resource for trials of PAH prevention.
In addition, collaborative studies of BMPR2 mutation carriers should enable identification of environmental modifiers, biomarkers for disease development and progression, and surrogate markers for efficacy end points in clinical drug development, thereby providing an invaluable resource for trials of PAH prevention.
In particular, genetic alterations of BMPR2 gene are associated with several clinical disorders, including representative pulmonary arterial hypertension, cancers, and metabolic diseases, thus demonstrating the physiological importance of BMPR2.