Department of Surgery, University of Michigan Health System, Ann Arbor, Michigan, United States.
Department of Surgery, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China.
Curr Mol Med. 2018;18(10):711-718. doi: 10.2174/1566524019666190208102729.
Cardiac reperfusion injury can have devastating consequences. Histone deacetylase (HDAC) inhibitors are potent cytoprotective agents, but their role in the prevention of cardiac injury remains ill-defined.
We sought to determine the therapeutic potential of HDAC inhibitors in an in vitro model of cardiomyocyte hypoxia-reoxygenation (H/R).
H9c2 cardiomyocytes were subjected to H/R and treated with various classspecific and pan-HDAC inhibitors in equal concentrations (5µM). Biological activity of inhibitors was determined, as a proxy for concentration adequacy, by Western blot for acetylated histone H3 and α-tubulin. Cell viability and cytotoxicity were measured by methyl thiazolyl tetrazolium and lactate dehydrogenase assays, respectively. Mechanistic studies were performed to better define the effects of the most effective agent, Tubastatin-A (Tub-A), on the phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway effectors, and on the degree of autophagy.
All inhibitors acetylated well-known target proteins (histone H3 and α-tubulin), suggesting that concentrations were adequate to induce a biological effect. Improved cell viability and decreased cell cytotoxicity were noted in cardiomyocytes exposed to Tub-A, whereas the cytoprotective effects of other HDAC inhibitors were inconsistent. Pro-survival mediators in the PI3K/mTOR pathway were up-regulated and the degree of autophagy was significantly attenuated in cells that were treated with Tub-A.
HDAC inhibitors improve cell viability in a model of cardiomyocyte H/R, with Class IIb inhibition (Tub-A) demonstrating superior cellular-level potency and effectiveness. This effect is, at least in part, related to an increased expression of prosurvival mediators and a decreased degree of autophagy.
心肌再灌注损伤可能会产生毁灭性的后果。组蛋白去乙酰化酶（HDAC）抑制剂是一种有效的细胞保护剂，但它们在预防心肌损伤方面的作用仍未明确。
我们旨在通过体外心肌细胞缺氧-复氧（H/R）模型来确定 HDAC 抑制剂的治疗潜力。
将 H9c2 心肌细胞进行 H/R 处理，并以相等浓度（5µM）用各种类特异性和泛 HDAC 抑制剂进行处理。通过 Western blot 检测乙酰化组蛋白 H3 和α-微管蛋白来确定抑制剂的生物活性，作为浓度适宜性的替代指标。通过甲基噻唑基四唑和乳酸脱氢酶测定分别测量细胞活力和细胞毒性。进行机制研究以更好地定义最有效的药物 Tubastatin-A（Tub-A）对磷酸肌醇 3-激酶（PI3K）/雷帕霉素靶蛋白（mTOR）通路效应物的影响，以及对自噬程度的影响。
所有抑制剂都能很好地乙酰化已知的靶蛋白（组蛋白 H3 和α-微管蛋白），这表明浓度足以诱导生物学效应。与其他 HDAC 抑制剂相比，Tub-A 处理的心肌细胞中观察到细胞活力提高和细胞毒性降低。PI3K/mTOR 通路中的促生存介质上调，并且用 Tub-A 处理的细胞中自噬程度明显减弱。
HDAC 抑制剂可改善心肌细胞 H/R 模型中的细胞活力，其中 IIb 类抑制（Tub-A）显示出优越的细胞水平效力和有效性。这种作用至少部分与促生存介质表达增加和自噬程度降低有关。
