Cathepsin L inhibitor suppresses oxidative stress-induced apoptosis of retinal pigment epithelial cells by targeting mitochondria
10.3760/cma.j.cn511434-20231207-00474
- VernacularTitle:组织蛋白酶L抑制剂经线粒体途径抑制氧化应激诱导的视网膜色素上皮细胞凋亡
- Author:
Zhen HE
1
;
Zhenyu KOU
;
Lijie DONG
;
Xiaorong LI
Author Information
1. 天津医科大学眼科医院、眼视光学院、眼科研究所 国家眼耳鼻喉疾病临床医学研究中心天津市分中心 天津市视网膜功能与疾病重点实验室，天津 300384
- Keywords:
Cathepsin L;
Retinal pigment epithelial cells;
Cell apoptosis;
Oxidative stress;
Mitochondria;
Cell experiment
- From:
Chinese Journal of Ocular Fundus Diseases
2024;40(5):379-386
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore the effect of cathepsin L (CTSL) inhibitor on apoptosis of retinal pigment epithelial (RPE) cells and mitochondrial oxidative stress.Methods:RPE cells were cultured in vitro and divided into control group, hydrogen peroxide (H 2O 2) group, and H 2O 2+CTSL inhibitor group. The cells of H 2O 2 group and H 2O 2+CTSL inhibitor group were incubated in the medium containing 400 μmol/L H 2O 2 for 24 hours and 10 μmol/L CTSL inhibitor was added in H 2O 2+CTSL inhibitor group at the same time. The cells of normal group were routinely cultured cells. The follow-up experiment was carried out 24 hours after modeling. The rate of apoptosis was detected by flow cytometry. The expression of CTSL was detected by immunofluorescence staining, Western blot and real time-polymerase chain reaction. The level of mitochondrial super oxide was detected by MitoSOX fluorescent probe, and the mitochondrial structure was observed after MitoTracker staining, the average area, form factors, and branch of mitochondria were quantitatively analyzed. The two groups were compared using two-tailed Student t test, while numerous groups were compared using one-way ANOVA. Results:Compared with control group, the rate of apoptosis in H 2O 2 group was significantly higher ( t=3.307, P=0.029 7), the expression level of CTSL was significantly increased ( t=19.950, 6.916, 14.220; P<0.05). Compared with H 2O 2 group, the expression level of CTSL, the rate of apoptosis and the mitochondrial ROS level in H 2O 2+CTSL inhibitor group were significantly lower ( t=11.940, 4.718, 16.680; P<0.05). The mitochondria of H 2O 2+CTSL inhibitor group were elongated, oval-shaped or rod-shaped, while the mitochondria of H 2O 2 group lost their continuous contour shape and complete structure. The differences of the average area, form factors, and brach of mitochondria among 4 groups were statistically significant ( F=251.700, 34.010, 60.500; P<0.000 1). Conclusions:H 2O 2 can significantly induce apoptosis in RPE cells and increase CTSL expression. CTSL inhibitor can inhibit the H 2O 2-induced apoptosis of RPE cells, lower the mitochondrial super oxide level, and successfully repair the mitochondrial structure.
