Expression of procollagen C‐proteinase enhancer in cultured rat heart fibroblasts: Evidence for co‐regulation with type I collagen

Abstract

Procollagen processing by procollagen C-proteinase (PCP) is an important step in collagen deposition. This reaction is stimulated by another glycoprotein, known as PCP enhancer. The objective of this study was to identify factors that regulate the expression of PCP enhancer in cardiac fibroblasts and examine possible correlation with collagen expression. Rat heart fibroblasts were cultured in the presence or absence of three known stimulators of collagen synthesis: ascorbic acid, TGF-beta, and aldosterone. The mRNA and protein levels of PCP enhancer and collagen type I were each assessed using Northern and Western blotting, respectively. Expression of PCP was assessed by RT-PCR and its activity in the culture media was determined using radioactive procollagen as the substrate. The levels of PCP enhancer mRNA increased 1.5- to 2-fold in response to ascorbate, TGF-beta, or aldosterone. This increase was paralleled by an up to fourfold increase in the level of the pro alpha1(I) collagen chain transcript and was accompanied by a marked increase in the levels of the respective proteins in the culture media. PCP activity in the culture media was also increased, apparently, without effect on its expression. These results indicate that expression of PCP enhancer in cultured rat heart fibroblasts is coordinated with that of collagen. The observed augmentation of PCP activity may be a consequence of the increase in the levels of PCP enhancer in the culture media.

Exogenously administered secreted frizzled related protein 2 (Sfrp2) reduces fibrosis and improves cardiac function in a rat model of myocardial infarction

“…Cardiac fibroblasts are the major source of collagen deposition and play a key role in the scar formation after MI (12). Bmp1 expression has been detected in primary culture of cardiac fibroblast, and PCP activity has been shown to increase in response to collagen-inducing reagents (13). To test whether Sfrp2 has any effects on procollagen maturation in cardiac fibroblasts, we first used conditioned medium from these cells as substrate to perform in vitro Bmp1 cleavage assay.…”

mRNA and protein expression of FGF-1, FGF-2 and their receptors in the porcine umbilical cord during pregnancy.

“…Concentration among the mentioned structures of the umbilical cord was not different for FGF-1 [21]. The high amounts of growth factors may strongly stimulate cells of Wharton's jelly to biosynthesize collagen, hyaluronate and sulphated proteoglycans [32][33][34]. Previous study of Sobolewski and coworkers [4] showed that Wharton's jelly contains about four times more collagen and twice as much glycosaminoglycan com- pared to the umbilical cord artery wall.…”

Diagnosis and Treatment of Myocardial Fibrosis in Hypertensive Heart Disease

“…24 Interestingly, torasemide, but not furosemide, has been reported to prevent cardiac uptake of aldosterone in heart failure patients, 33 and to block the binding of the hormone to the mineralocorticoid receptor. 34 Because aldosterone has been found to increase PCPase activity in cultured rat cardiac fibroblasts, 35 it is possible that the antifibrotic effect of torasemide in heart failure patients is related to interference with the fibrogenic actions of aldosterone at the PCPase level.…”