BMP7-based peptide agonists of BMPR1A protect the left ventricle against pathological remodeling induced by pressure overload.

ABSTRACT

Aortic stenosis (AS) exposes the left ventricle (LV) to pressure overload leading to detrimental LV remodeling and heart failure. In animal models of cardiac injury or hemodynamic stress, bone morphogenetic protein-7 (BMP7) protects LV against remodeling by counteracting TGF-ß effects. BMP receptor 1A (BMPR1A) might mediate BMP7 antifibrotic effects. Herein we evaluated BMP7-based peptides, THR123 and THR184, agonists of BMPR1A, as cardioprotective drugs in a pressure overload model. We studied patients with AS, mice subjected to four-week transverse aortic constriction (TAC) and TAC release (de-TAC). The LV of AS patients and TAC mice featured Bmpr1a downregulation. Also, pSMAD1/5/(8)9 was reduced in TAC mice. Pre-emptive treatment of mice with THR123 and THR184, during the four-week TAC period, normalized pSMAD1/5/(8)9 levels in the LV, attenuated overexpression of remodeling-related genes (Col 1α1, ß-MHC, BNP), palliated structural damage (hypertrophy and fibrosis) and alleviated LV dysfunction (systolic and diastolic). THR184 administration, starting fifteen days after TAC, halted the ongoing remodeling and partially reversed LV dysfunction. The reverse remodeling after pressure overload release was facilitated by THR184. Both peptides diminished the TGF-ß1-induced hypertrophic gene program in cardiomyocytes, collagen transcriptional activation in fibroblasts, and differentiation of cardiac fibroblasts to myofibroblasts. Molecular docking suggests that both peptides bind with similar binding energies to the BMP7 binding domain at the BMPR1A. The present study results provide a preclinical proof-of-concept of potential therapeutic benefits of BMP7-based small peptides, which function as agonists of BMPR1A, against the pathological LV remodeling in the context of aortic stenosis.