Contribution of hypoxia-inducible factor 1alpha to pathogenesis of sarcomeric hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) caused by autosomal-dominant mutations in genes coding for structural sarcomeric proteins, is the most common inherited heart disease. HCM is associated with myocardial hypertrophy, fibrosis and ventricular dysfunction. Hypoxia-inducible transcription factor-1α (Hif-1α) is the central master regulators of cellular hypoxia response and associated with HCM.

Cardiac fibroblast BAG3 regulates TGFBR2 signaling and fibrosis in dilated cardiomyopathy.

Loss of Bcl2-associated athanogene 3 (BAG3) is associated with dilated cardiomyopathy (DCM). BAG3 regulates sarcomere protein turnover in cardiomyocytes; however, the function of BAG3 in other cardiac cell types is understudied. In this study, we used an isogenic pair of BAG3-knockout and wild-type human induced pluripotent stem cells (hiPSCs) to interrogate the role of BAG3 in hiPSC-derived cardiac fibroblasts (CFs).

Regulation of sarcomere formation and function in the healthy heart requires a titin intronic enhancer.

Heterozygous truncating variants in the sarcomere protein titin (TTN) are the most common genetic cause of heart failure. To understand mechanisms that regulate abundant cardiomyocyte TTN expression we characterized highly conserved intron 1 sequences that exhibited dynamic changes in chromatin accessibility during differentiation of human cardiomyocytes from induced pluripotent stem cells (hiPSC-CMs). Homozygous deletion of these sequences in mice caused embryonic lethality while heterozygous mice demonstrated allele-specific reduction in Ttn expression.

Preoperative methionine restriction induces perivascular adipose tissue browning and improves vein graft remodeling in male mice.

Short-term preoperative methionine restriction (MetR) is a promising translatable strategy to mitigate surgical injury response. However, its application to improve post-interventional vascular remodeling remains underexplored. Here we find that MetR protects from arterial intimal hyperplasia in a focal stenosis model and pathologic vascular remodeling following vein graft surgery in male mice.