Description
The heart responds to pathological overload through myocyte hypertrophy. In our study, we found that this response is regulated by cardiac fibroblasts via a novel paracrine mechanism involving plasma membrane calcium ATPase 4 (PMCA4). PMCA4 deletion in mice, both systemically and specifically in fibroblasts, reduces the hypertrophic response to pressure overload; however, knocking out PMCA4 specifically in cardiomyocytes does not produce this effect. Mechanistically, our microarray data on fibroblasts isolated from PMCA4 WT and PMCA4 knockout animals showed that cardiac fibroblasts lacking PMCA4 produce higher levels of secreted frizzled related protein 2 (sFRP2), which inhibits the hypertrophic response in neighbouring cardiomyocytes.