Dataset Information

Loss of Acta2 in cardiac fibroblasts does not prevent the myofibroblast differentiation or affect the cardiac repair after myocardial infarction

ABSTRACT: In response to myocardial infarction (MI), quiescent cardiac fibroblasts differentiate into myofibroblasts mediating tissue repair in the infarcted area. One of the most widely accepted markers of myofibroblast differentiation is the expression of Acta2 which encodes smooth muscle alpha-actin (SMαA) that is assembled into stress fibers. However, the requirement of Acta2/ SMαA in the myofibroblast differentiation of cardiac fibroblasts and its role in post-MI cardiac repair remained largely unknown. To answer these questions, we generated a tamoxifen-inducible cardiac fibroblast-specific Acta2 knockout mouse line. Surprisingly, mice that lacked Acta2 in cardiac fibroblasts had a normal survival rate after MI. Moreover, Acta2 deletion did not affect the function or overall histology of infarcted hearts. No difference was detected in the proliferation, migration, or contractility between WT and Acta2-null cardiac myofibroblasts. It was identified that Acta2-null cardiac myofibroblasts had a normal total filamentous actin level and total actin level. Acta2 deletion caused a significant compensatory increase in the transcription level of non- Acta2 actin isoforms, especially Actg2 and Acta1, 2 other muscle actin isoforms. Moreover, in myofibroblasts the transcription levels of cytoplasmic actin isoforms were significantly higher than those of muscle actin isoforms. In addition, we found that myocardin-related transcription factor-A is critical for myofibroblast differentiation but is not required for the compensatory effects of non-Acta2 isoforms. In conclusion, the deletion of Acta2 does not prevent the myofibroblast differentiation of cardiac fibroblasts or affect the post-MI cardiac repair, and the increased expression and stress fiber formation of non-SMαA actin isoforms and the functional redundancy between actin isoforms are able to compensate for the loss of Acta2 in cardiac myofibroblasts.

ORGANISM(S): Mus musculus

PROVIDER: GSE193163 | GEO | 2022/01/10

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Pericryptal myofibroblasts in the colon and rectum play an important role in regulating the normal colorectal stem cell niche and facilitating tumour progression. Myofibroblasts have previously mostly been distinguished from normal fibroblasts only by the expression of Î± smooth muscle actin (Î±SMA). We now identify AOC3, a surface monoamine oxidase, as a new marker of myofibroblasts by showing that it is the target protein of the myofibroblast reacting monoclonal antibody (mAb), PR2D3. The normal and tumour tissue distribution and the cell line reactivity of AOC3 match that expected for myofibroblasts. We have shown that the surface expression of AOC3 is sensitive to digestion by trypsin and collagenase and that anti-AOC3 antibodies can be used for FACS sorting of myofibroblasts obtained by non-enzymatic procedures. Whole genome microarray mRNA expression profiles of myofibroblasts and skin fibroblasts revealed four additional genes that are significantly expressed differentially between these two cell types; NKX2-3 and LRRC17 are expressed in myofibroblasts and SHOX2 and TBX5 in skin fibroblasts. Transforming Growth Factor Î² (TGFÎ²) substantially down-regulated AOC3 expression in myofibroblasts but not in skin fibroblasts, in which it dramatically increased the expression of Î±SMA. A knockdown of NKX2-3 in myofibroblasts caused a decrease of myofibroblast-related gene expression and an increased expression of the fibroblast associated gene, SHOX2, suggesting that NKX2-3 is a key mediator for maintaining myofibroblast characteristics. Our results show that colorectal myofibroblasts, as defined by the expression of AOC3, NKX2-3 and other markers, are a distinctly different cell type from TGFÎ² activated fibroblasts. colorectal myofibroblast specific markers and expression profiles were sought by comparing four primary myofibroblast cultures to a panel of four dermal and foreskin fibroblast cell lines Four primary myofibroblast cultures established from adult human colon compared to four skin fibroblast cell lines to identify intestinal myofibroblast specific markers

Dataset Information

Loss of Acta2 in cardiac fibroblasts does not prevent the myofibroblast differentiation or affect the cardiac repair after myocardial infarction

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets