Fibroblasts residing in connective tissues throughout the body are responsible for extracellular matrix (ECM) homeostasis and repair. In response to tissue damage, they activate to become myofibroblasts, which have organized contractile cytoskeletons and produce a myriad of proteins for ECM remodeling. However, persistence of myofibroblasts can lead to fibrosis with excessive collagen depositio...

S u m m a r y . Human skin wounds (66) inflicted between 20 h and 7 months prior to biopsy were studied. In order to identify the type of cellular differentiation of the fibroblastic cells in the granulation tissue, alpha-smooth muscle actin and desmin were immunohistochemically localized. The value of any presumed time-dependent appearance and/or disappearance of positively stained cells was t...

The formation of myofibroblasts in valve interstitial cell (VIC) populations contributes to fibrotic valvular disease. We examined myofibroblast differentiation in VICs from porcine aortic valves. In normal valves, cells immunostained for alpha-smooth muscle actin (alpha-SMA, a myofibroblast marker) were rare (0.69 +/- 0.48%), but in sclerotic valves of animals fed an atherogenic diet, myofibro...

Whence Cometh Neointimal Myofibroblasts? To the Editor: We greatly enjoyed the elegant and informative study recently published by Shi and colleagues. Using bromodeoxyuridine (BrdU) labeling after severe endoluminal coronary artery injury, the authors demonstrated activation and proliferation of porcine adventitial fibroblasts that initially lacked actin expression. Subsequently, the adventitia...

Abstract Introduction: Myofibroblasts are the main stromal components that constitute the desmoplastic reaction of host cells to inductive stimuli exerted by tumor cells. The purpose of this study was to evaluate the score of myofibroblasts using α -smooth muscle actin marker (α–SMA) in mucoepidermoid carcinoma (MEC) in comparison with pleomorphic adenoma (PA)and study the amount presence of t...

Epithelial-mesenchymal transition (EMT) is a complex reversible biological process characterized by the loss of epithelial features and acquisition mesenchymal features. EMT was initially described in developmental processes further associated with pathological conditions including metastatic cascade arising neoplastic progression organ fibrosis. Fibrosis delineated an excessive number myofibro...

Myofibroblasts are matrix-producing cells with contractile properties, usually characterized by de novo expression of alpha-smooth muscle actin, that arise in fibrotic diseases. Hepatic stellate cells (HSCs), known as perisinusoidal cells containing auto-fluorescent vitamin A, are the major although not exclusive source of myofibroblasts in the injured liver. Portal myofibroblasts (PMFs) have b...

Fibroblasts and myofibroblasts in the tumor microenvironment are important players in tumor growth and metastasis because of their unique ability to coordinate events which increase cell proliferation and invasion especially in breast cancer. It has been experimentally shown that fibroblasts play an important role in promoting tumor growth. Our study illustrates a model in which tumor cells are...