Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Higashi 23 Bancho 35-1, Towada, Aomori 034-8628, Japan.
Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Higashi 23 Bancho 35-1, Towada, Aomori 034-8628, Japan.
Eur J Pharmacol. 2017 Jul 15;807:64-70. doi: 10.1016/j.ejphar.2017.04.032. Epub 2017 Apr 27.
Tumstatin, a cleaved fragment of α3 chain of type IV collagen, is an endogenous anti-angiogenetic peptide. Although the expression level of tumstatin changes in the heart tissues of certain experimental cardiac disease models, its effect on cardiomyocytes has not been clarified. In this study, we examined the effects of T3 peptide, an active subfragment of tumstatin, on hydrogen peroxide (HO)-induced cell death in H9c2 cardiomyoblasts. Cell viability was examined by a cell counting assay. Staining using 4', 6-diamidino-2-phenylindole was performed to observe nuclear morphology. Western blotting was performed to examine cleaved caspase-3 expression. Mitochondrial membrane potential and morphology were detected by a Mito Tracker Red staining. Intracellular reactive oxygen species production was examined by 2', 7'-dichlorodihydrofluorescein diacetate staining. T3 peptide (300, 1000ng/ml) suppressed HO (1mM)-induced cell death, apoptotic changes of nuclei and cleaved caspas-3 expression in a concentration-dependent manner. T3 peptide also inhibited HO-induced loss of mitochondrial membrane potential, mitochondrial fission and reactive oxygen species production. Cilengitide, an integrin αβ/αβ inhibitor, prevents the inhibitory effect of T3 peptide on HO-induced reactive oxygen species production. In conclusion, T3 peptide inhibits HO-induced apoptosis at least partly via the inhibition of intracellular reactive oxygen species production through the action on integrin.
肿瘤抑素，IV 型胶原α3 链的断裂片段，是一种内源性抗血管生成肽。虽然肿瘤抑素的表达水平在某些实验性心脏疾病模型的心脏组织中发生变化，但它对心肌细胞的影响尚未阐明。在这项研究中，我们研究了 T3 肽（肿瘤抑素的活性亚片段）对 H9c2 心肌细胞中过氧化氢（HO）诱导的细胞死亡的影响。通过细胞计数法检查细胞活力。使用 4'，6-二脒基-2-苯基吲哚进行染色以观察核形态。通过 Western blot 检查裂解的 caspase-3 表达。通过 Mito Tracker Red 染色检测线粒体膜电位和形态。通过 2'，7'-二氯二氢荧光素二乙酸酯染色检查细胞内活性氧的产生。T3 肽（300、1000ng/ml）以浓度依赖性方式抑制 HO（1mM）诱导的细胞死亡、核的凋亡变化和裂解的 caspase-3 表达。T3 肽还抑制了 HO 诱导的线粒体膜电位丧失、线粒体分裂和活性氧的产生。西利单抗，整合素αβ/αβ抑制剂，可防止 T3 肽抑制 HO 诱导的活性氧产生的作用。总之，T3 肽通过抑制整合素的作用抑制 HO 诱导的细胞内活性氧的产生，从而至少部分抑制细胞凋亡。
