P305By promoting cardiac regeneration FGF10 preserves cardiac remodeling and function after myocardial infarction

Finsen, Alexandra Vanessa, Per Reidar Woldbaek, Jian Li, Jiaping Wu, Torstein Lyberg, Theis Tonnessen, and Geir Christensen. Increased syndecan expression following myocardial infarction indicates a role in cardiac remodeling. Physiol Genomics 16: 301-308, 2004. First published November 18, 2003; 10.1152/physi-olgenomics. 00144.2002.—The purpose of this study was to identify essential genes involved in myocardial growth and remodeling following myocardial infarction (MI). Left ventricular noninfarcted tissues from six mice subjected to MI under general anesthesia and from six sham-operated mice were obtained 1 wk after primary surgery and analyzed by means of cDNA filter arrays. Out of a total of 1,176 genes, 641 were consistently expressed, twenty-three were upregulated and thirteen downregulated. Five genes were only expressed following MI. Syndecan-3, a transmembranous heparan sulfate proteoglycan, was found to be upregulated together with a transcriptional activator of syndecans, Wilms tumor protein 1 (WT-1). Northern blotting demonstrated a significant upregulation of syndecan-1, -2, -3, and -4, WT-1, fibronectin, and basic fibroblast growth factor (FGF) receptor 1. Furthermore, Western blot analysis showed statistically significant increases in protein levels for syndecan-3 and -4. In conclusion, we have identified a subset of genes with increased expression in noninfarcted left ventricular tissue following MI, including syndecans 1–4, WT-1, fibronectin, collagen 6A, and FGF receptor 1. Since the syndecans link the cytoskeleton to the extracellular matrix and function as required coreceptors for FGF, we suggest a role for the syndecans in cardiac remodeling following MI.

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miR155 Deficiency Reduces Myofibroblast Density but Fails to Improve Cardiac Function after Myocardial Infarction in Dyslipidemic Mouse Model

International Journal of Molecular Sciences ◽

10.3390/ijms22115480 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5480

Author(s):

David Schumacher ◽

Adelina Curaj ◽

Sakine Simsekyilmaz ◽

Andreas Schober ◽

Elisa A. Liehn ◽

...

Keyword(s):

Myocardial Infarction ◽

Heart Failure ◽

Mouse Model ◽

Cardiac Remodeling ◽

Left Ventricular ◽

Cardiomyocyte Hypertrophy ◽

Cardiac Inflammation ◽

Infarction Size ◽

Adverse Remodeling ◽

And Function

Myocardial infarction remains the most common cause of heart failure with adverse remodeling. MicroRNA (miR)155 is upregulated following myocardial infarction and represents a relevant regulatory factor for cardiac remodeling by engagement in cardiac inflammation, fibrosis and cardiomyocyte hypertrophy. Here, we investigated the role of miR155 in cardiac remodeling and dysfunction following myocardial infarction in a dyslipidemic mouse model. Myocardial infarction was induced in dyslipidemic apolipoprotein E-deficient (ApoE−/−) mice with and without additional miR155 knockout by ligation of the LAD. Four weeks later, echocardiography was performed to assess left ventricular (LV) dimensions and function, and mice were subsequently sacrificed for histological analysis. Echocardiography revealed no difference in LV ejection fractions, LV mass and LV volumes between ApoE−/− and ApoE−/−/miR155−/− mice. Histology confirmed comparable infarction size and unaltered neoangiogenesis in the myocardial scar. Notably, myofibroblast density was significantly decreased in ApoE−/−/miR155−/− mice compared to the control, but no difference was observed for total collagen deposition. Our findings reveal that genetic depletion of miR155 in a dyslipidemic mouse model of myocardial infarction does not reduce infarction size and consecutive heart failure but does decrease myofibroblast density in the post-ischemic scar.

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