Fibroblast involvement in cardiac remodeling and repair under ischemic conditions

Abstract

Cardiac fibroblasts play a main role in the physio logical turnover of the extracellular matrix, as well as its pathological remodeling. A study was performed on a batch of 23 cases who died of various cardiac complications secondary to scarring myocardial infarctions. The aim of the study was to assess the fibroblast involvement in cardiac repair under isch emic conditions after myocardial infarction. Tissue myocardial samples from the left ventricle were taken from these cases for microscopy examination, in order to investigate the type and degree of fibrosis as well as the presence of cardiac interstitial fibroblasts. Multiple series of histological sections were also performed and examined, along with immunohistochemical analysis. The fibroblasts were diffusely distributed in the interstitium among the residual cardiomyocytes, showing variable expression of vimentin and smooth muscle actin. During cardiac remodeling, there was a successive interstitial deposition, first of reticulin fibers and then of collagen fibers, leading to interstitial fibrosis and myocardial replacement.There was a correlation between vimentin and smooth muscle actin expression and collagen deposition. Fibrosis with cardiac remodeling is based on maintaining proliferation capacity of the fibroblast and its capacity of protein synthesis in the extra cellular matrix. Under hypoxic ischemic conditions, followed by myocardial infarction, the fibroblast switches phenotype and transdifferentiate into myofibroblast, contributing to the healing by secreting extracellular matrix proteins and collagen deposition, with subsequent cardiac remodeling and regulation of the microenvironment metabolism.

Influence of the microenvironment dynamics on extracellular matrix evolution under hypoxic ischemic conditions in the myocardium

“…Subsequent expansion of macrophage population in viable zones is stimulated by chemokines, as a consequence of a high wall stress. Activation of macrophages in the vascularized aria of the myocardium may lead to development and progression of heart failure (36,37).…”

Micropatterned conductive elastomer patch based on poly (glycerol sebacate)-graphene for cardiac tissue repair

“…In addition, the ventricular wall thickness of the PGS-Gr1 group was the largest that was significantly different from the PGS and MI control groups (figures 7(a) and (c)). Fibroblasts are located around cardiomyocytes during ventricular remodeling, producing and depositing collagen [81]; therefore, collagen deposition is also an indicator to evaluate MI. Thus, collagen deposition in the infarct area was evaluated by Masson's trichrome staining (figures 7(b) and (d)).…”

Novel Therapies for the Treatment of Cardiac Fibrosis Following Myocardial Infarction

“…In the next proliferative phase, which usually lasts from a few days to a month, the immune cells such as macrophages, mast cells, and lymphocytes are recruited [ 34 ]. They secrete mediators including cytokines, growth factors, and matricellular proteins that initiate transdifferentiation of cardiac fibroblasts into myofibroblasts, whose functions include the change in cell proliferation and migration, the expression of ECM proteins, and the secretion of bioactive molecules [ 35 ].…”