Bmpr2, also known as bone morphogenetic protein receptor 2, is a key receptor in the bone morphogenetic protein (BMP) signaling pathway. BMPs are part of the TGF-β superfamily, and Bmpr2 signaling plays a crucial role in various biological processes, including cell proliferation, apoptosis, and differentiation. Dysfunction in this signaling pathway has been associated with multiple diseases, highlighting its biological importance. Genetic models, such as gene knockout (KO) and conditional knockout (CKO) mouse models, are valuable tools for studying Bmpr2 function.

SMC-specific Bmpr2 -/- (BKOSMC) mice, a type of CKO mouse model, showed reduced hypoxia-induced vasoconstriction and persistent pulmonary hypertension following recovery from hypoxia. PASMC from these mutant mice had reduced contractility, increased proliferation, and apoptosis resistance compared to controls. This phenotype was related to upregulation of pERK1/2-pP38-pSMAD2/3, mediating elevation in ARRB2, pAKT inactivation of GSK3-beta, CTNNB1 nuclear translocation, and reduction in RHOA and RAC1 [1].

In conclusion, Bmpr2 is essential in regulating cell-related processes through its signaling pathway. The use of KO/CKO mouse models, like the SMC-specific Bmpr2 -/- mice, has significantly contributed to understanding its role in pulmonary hypertension, revealing how its loss-of-function can lead to abnormal phenotypes in pulmonary artery smooth muscle cells and ultimately drive the development of the disease.