Reversible and irreversible differentiation of cardiac fibroblasts
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ABSTRACT: Aim: Differentiation of cardiac fibroblasts (Fb) into myofibroblasts (MyoFb) is responsible for connective tissue buildup in myocardial remodeling. We examined reversibility of MyoFb differentiation. Methods and Results: Adult rat cardiac Fb were cultured on a plastic substratum providing mechanical stress, with conditions to obtain different Fb phenotypes. Fb spontaneously differentiated to proliferating MyoFb (p-MyoFb) with stress fiber formation decorated with alpha-smooth muscle actin (α-SMA). Transforming growth factor-β1 (TGF-β1) promoted terminal differentiation into α-SMA positive MyoFb showing near absence of proliferation i.e. non-p-MyoFb (2-fold increase in cell number after 12 days vs 11-fold for p-MyoFb). SD-208, a TGF-β-receptor-I kinase blocker, inhibited p-MyoFb differentiation as shown by stress fiber absence, low levels of α-SMA protein expression, and high levels of proliferation (32-fold increase after 12 days). Fb seeded in collagen matrices induced no contraction, whereas p-MyoFb and non-p-MyoFb induced 2.5- and 4-fold contraction. Fb produced low levels of collagen and secreted high levels of IL-10. Non-p-MyoFb showed high collagen production and high MCP-1 and TIMP-1 secretion. Transcriptome analysis indicated differential gene expression between all phenotypes. Dedifferentiation of p-MyoFb, but not of non-p-MyoFb, was induced by SD-208 despite maintained stress, shown by stress fiber de-polymerization in 30% of p-MyoFb vs in 8% of non-p-MyoFb. Stress fiber de-polymerization could be induced by mechanical strain release in p-MyoFb and non-p-MyoFb (2 day culture in unrestrained 3-D collagen matrices). Only p-MyoFb showed true dedifferentiation after long-term 3-D culture. Conclusions: Both reduction in mechanical strain and TGF-β-receptor-I kinase inhibition can reverse p-MyoFb differentiation but not in non-p-MyoFb.
ORGANISM(S): Rattus norvegicus
PROVIDER: GSE51824 | GEO | 2014/01/07
SECONDARY ACCESSION(S): PRJNA225508
REPOSITORIES: GEO
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