Department of Protection Science, Kyungwoon University, Kumi 730‑739, Republic of Korea.
Mol Med Rep. 2013 Jun;7(6):1745-50. doi: 10.3892/mmr.2013.1439. Epub 2013 Apr 25.
Apoptotic neuronal cell death in the retina is a hallmark of diabetic retinopathy. Exercise has been recommended for the alleviation of symptoms in patients with diabetes. In the present study, the effect of treadmill exercise on apoptosis in the retinas of diabetic rats was investigated. Diabetes was induced by intraperitoneal injection of streptozotocin. The rats in the exercise groups ran on a treadmill for 30 min/day, 5 times a week, over the course of 6 weeks. In this study, the terminal deoxynucleotidyl transferase‑mediated dUTP nick‑end labeling (TUNEL) assay, immunohistochemistry staining of caspase‑3 and western blot analysis for Bax, Bcl‑2 and phosphorylated protein kinase B (p‑Akt) in the retinas of diabetic rats were performed. The results demonstrated that the number of TUNEL‑ and caspase‑3‑positive cells was increased in the retinas of diabetic rats, whereas treadmill exercise decreased these numbers. In addition, the expression of the pro‑apoptotic protein Bax and the anti‑apoptotic protein Bcl‑2 was enhanced in the retinas of diabetic rats. Treadmill exercise suppressed Bax and enhanced Bcl‑2 levels. The expression of the cell survival factor, p‑Akt, was decreased in the retinas of diabetic rats and treadmill exercise increased the expression of p‑Akt. The results of the present study demonstrated that treadmill exercise ameliorated diabetes‑induced apoptosis in retinal cells by enhancing p‑Akt levels in the retina. Treadmill exercise represents an effective strategy to delay or prevent the onset of ocular complications in diabetic patients.
视网膜神经元细胞凋亡是糖尿病性视网膜病变的一个标志。运动已被推荐用于缓解糖尿病患者的症状。在本研究中，研究了跑步机运动对糖尿病大鼠视网膜细胞凋亡的影响。糖尿病通过腹腔注射链脲佐菌素诱导。运动组大鼠每周 5 天，每天在跑步机上跑步 30 分钟，持续 6 周。在这项研究中，进行了末端脱氧核苷酸转移酶介导的 dUTP 缺口末端标记（TUNEL）检测、caspase-3 的免疫组织化学染色以及视网膜中 Bax、Bcl-2 和磷酸化蛋白激酶 B（p-Akt）的 Western blot 分析。结果表明，糖尿病大鼠视网膜中 TUNEL 和 caspase-3 阳性细胞的数量增加，而跑步机运动则减少了这些数量。此外，糖尿病大鼠视网膜中促凋亡蛋白 Bax 和抗凋亡蛋白 Bcl-2 的表达增强。跑步机运动抑制 Bax 并增强 Bcl-2 水平。糖尿病大鼠视网膜中细胞存活因子 p-Akt 的表达降低，而跑步机运动增加了 p-Akt 的表达。本研究的结果表明，跑步机运动通过增强视网膜中的 p-Akt 水平，改善了糖尿病诱导的视网膜细胞凋亡。跑步机运动代表了一种有效策略，可以延迟或预防糖尿病患者眼部并发症的发生。
