Cardiac fibroblast to myofibroblast differentiation in vivo and in vitro: Expression of focal adhesion components in neonatal and adult rat ventricular myofibroblasts

Abstract

In fibrosing hearts, myofibroblasts are associated with cardiac extracellular matrix remodeling. Expression of key genes in the transition of cardiac fibroblast to myofibroblast phenotype in post-myocardial infarction heart and in vitro has not been well addressed. Contractile, focal adhesion-associated, receptor proteins, fibroblast growth factor-2 (FGF-2) expression, and motility were compared to assess phenotype in adult and neonatal rat cardiac fibroblasts and myofibroblasts. Neonatal and adult fibroblasts undergo phenotypic transition to myofibroblastic cells, marked by increased a-smooth muscle actin (aSMA), smooth muscle myosin heavy chain (SMemb), extra domain-A (ED-A) fibronectin, paxillin, tensin, FGF-2, and TbRII receptor. Elevated ED-A fibronectin confirmed fibroblast to supermature myofibroblastic phenotype transition. Presence of myofibroblasts in vivo was noted in sections of healed infarct scar after myocardial infarction, and their expression is similar to that in culture. Thus, cultured neonatal and adult cardiac fibroblasts transition to myofibroblasts in vitro and share expression profiles of cardiac myofibroblasts in vivo. Reduced motility with in vitro passage reflects enhanced production of focal adhesions. Developmental Dynamics 239:1573-1584,

Soluble CD74 Reroutes MIF/CXCR4/AKT‐Mediated Survival of Cardiac Myofibroblasts to Necroptosis

“…Yet, previous studies repeatedly demonstrated the reliability of using a model of neonatal fibroblasts, which provides comparable results to a model with adult fibroblasts 74, 75. Notwithstanding, this is the first study addressing the molecular mechanisms of action of sCD74 and MIF in cardiac fibrosis.…”

Isolation of Murine Coronary Vascular Smooth Muscle Cells

“…However, there is a possibility of contamination by adventitial and interstitial fibroblasts. To rule out this potential confound, we stained isolated cells for SM22α, α-smooth muscle actin (α-SMA), both VSMC markers 7,8 , and vimentin, a fibroblast marker 9 , at passages 1-2 ( Figure 2). We observed no change of these markers through passage 2.…”

Mast Cells and Cardiac Fibroblasts

“…Conversely, contractile and hypersynthetic myofibroblasts are the relevant phenotypic variants in wound healing or in hypertrophied and failing hearts. 3,4 Specific factors that signal for fibroblast-tomyofibroblast phenoconversion are now known and include mechanical loading or transforming growth factor-␤1 stimulation. An increase in ␣-smooth muscle actin in these cells 5 is synonymous with increased contractile force generation.…”

“…9 Thus, myofibroblasts are the primary mediators of wound healing in the damaged ventricle, and we have demonstrated previously that they are the dominant cell type in the infarct scar. 4,10 Investigation of these cells in hypertrophied hearts is clinically relevant, because they contribute to wound healing, matrix remodeling, and eventual cardiac fibrosis through the elevated production of fibrillar and nonfibrillar collagens. Much of the current literature that addresses cardiac fibroblast or myofibroblast function deals with the effects of a limited number of profibrotic factors and infrequently addresses the interplay of these stimuli.…”

“…Although ␣-smooth muscle actin is commonly held as the gold standard as a marker for cardiac myofibroblastic phenotype, an equally useful (and perhaps more sensitive) marker is extra domain-A (ED-A) fibronectin. 4 Its marked upregulation after exposure to tryptase is significant, because these cells may be actual myofibroblasts, which are now widely regarded to be important in remodeling of the matrix in various cardiac disease pathologies ( Figure). The possibility that tryptase/PAR-2 contributes to the phenoconversion of cardiac fibroblasts to myofibroblasts and the elevation of collagen synthesis is intriguing.…”