Author + information
- Jumpei Yasuda,
- Kana Fukui,
- Muneyoshi Okada and
- Hideyuki Yamawaki
Background: Tumstatin, a fragment of type IV collagen α3 chain, is known as an endogenous inhibitor of angiogenesis. Although the expression of tumstatin changes in heart tissues of experimental cardiac disease models, its pathophysiological role has not been clarified. In this study, we examined the effects of T3 peptide, an active fragment of tumstatin, on migration of cardiac fibroblasts and H2O2-induced cell death in H9c2 cardiomyoblasts.
Methods: Cardiac fibroblasts were isolated from adult male Wistar rats. Cells were treated with recombinant human T3 peptide (10-1000 ng/ml) for varying time. Boyden chamber assay was used to determine cell migration. Protein expression was detected by Western blotting. Cell counting assay was performed to determine cell viability. Staining using 4’, 6-diamidino-2-phenylindole was performed to observe nuclear morphology. Mitochondrial membrane potential and morphology were examined by a Mito Tracker Red staining. Intracellular reactive oxygen species (ROS) production was detected by 2’, 7'-dichlorodihydrofluorescein diacetate staining.
Results: In cardiac fibroblasts, T3 peptide (30, 300 ng/ml) significantly increased migration. T3 peptide (10-300 ng/ml) stimulated phosphorylation of Akt (Ser 473) and LY294002 (10 μμ), a PI3K/Akt pathway inhibitor, significantly inhibited the T3 peptide-induced migration of cardiac fibroblasts. In H9c2 cardiomyoblasts, T3 peptide (300-1000 ng/ml) significantly inhibited H2O2-induced decrease in cell viability, apoptotic morphological changes of nuclei, cleaved caspase-3 expression and increment of Bax/Bcl-2 ratio. T3 peptide (1000 ng/ml) also inhibited H2O2-induced loss of mitochondrial membrane potential, mitochondrial fission, and ROS production. Cilengitide (1 μμ), an integrin αvβ3/αvβ5 inhibitor, prevents the inhibitory effect of T3 peptide on H2O2-induced ROS production.
Conclusions: This study for the first time demonstrated that T3 peptide stimulates migration of cardiac fibroblasts via Akt activation and suppresses oxidative stress-induced apoptosis of cardiomyoblasts perhaps through binding to integrin.
Poster Hall, Hall C
Saturday, March 18, 2017, 3:45 p.m.-4:30 p.m.
Session Title: Cardiac Fibrosis and Heart Failure: The Next Frontier
Abstract Category: 12. Heart Failure and Cardiomyopathies: Basic
Presentation Number: 1249-261
- 2017 American College of Cardiology Foundation