Tingting Gao1,2, Chengqiang Tian3, Hui Xu2, Xin Tang2, Lvzhen Huang4, Mingwei Zhao5. 1. Department of Ophthalmology, Peking University Third Hospital, Beijing, China. 2. Department of Ophthalmology & Clinical Centre of Optometry, Eye diseases and optometry Institute, Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, College of Optometry, Peking University Health Science Center, Peking University People's Hospital, Xizhimen South Street 11, Xi Cheng District, Beijing, 100044, China. 3. Department of Ophthalmology, The First Affiliated Hospital of Dalian Medical University, Dalian, China. 4. Department of Ophthalmology & Clinical Centre of Optometry, Eye diseases and optometry Institute, Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, College of Optometry, Peking University Health Science Center, Peking University People's Hospital, Xizhimen South Street 11, Xi Cheng District, Beijing, 100044, China. huanglvzhen@126.com. 5. Department of Ophthalmology & Clinical Centre of Optometry, Eye diseases and optometry Institute, Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, College of Optometry, Peking University Health Science Center, Peking University People's Hospital, Xizhimen South Street 11, Xi Cheng District, Beijing, 100044, China. zhaomingwei64@163.com.
Abstract
PURPOSE: Best vitelliform macular dystrophy (BVMD) and autosomal recessive bestrophinopathy (ARB) are two kinds of bestrophinopathies which are caused by BEST1 mutations and characterized by accumulation of lipofuscin-like materials on the retinal pigment epithelium cell-photoreceptor interface. In the past two decades, research about the pathogenesis of bestrophinopathies was mainly focused on the anion channel and intracellular Ca2+ signaling, but seldom concentrated on the function of retinal pigment epithelium (RPE) cells. In this study, we explored the possible effect of the three BEST1 mutations p.V143F, p.S142G, and p.A146T on the apoptosis in human fetal RPE cells. METHODS: Wild-type plasmid and mutant plasmids BEST1-pcDNA3.1 p.V143F, p.S142G, and p.A146T were transfected to human fetal RPE cells. The molecules caspase-3, phospho-Bcl-2, BAX, PARP, and AIF associated with apoptosis were determined by quantitative PCR and Western blot. Apoptotic rate and active Caspase-3 staining were analyzed by flow cytometry. RESULTS: Caspase-3 and PARP expression were significantly increased in BEST1-pcDNA3.1 p.S142G and p.A146T group. Flow cytometry showed that the apoptosis rates were significantly increased in the BEST1-pcDNA3.1 p.V143F, p.S142G, and p.A146T group compared with the wild-type group. CONCLUSIONS: For the first time, we found that the three mutations promoted RPE cell apoptosis. Furthermore, the results indicated that BEST1 mutations p.S142G and p.A146T may contribute apoptosis of RPE cells by targeting Caspase 3. Our observations suggested that the apoptosis of RPE cells may be one of the mechanisms in bestrophinopathies, which may provide a new potential therapeutic target for the treatment of this disease.
PURPOSE: Best vitelliform macular dystrophy (BVMD) and autosomal recessive bestrophinopathy (ARB) are two kinds of bestrophinopathies which are caused by BEST1 mutations and characterized by accumulation of lipofuscin-like materials on the retinal pigment epithelium cell-photoreceptor interface. In the past two decades, research about the pathogenesis of bestrophinopathies was mainly focused on the anion channel and intracellular Ca2+ signaling, but seldom concentrated on the function of retinal pigment epithelium (RPE) cells. In this study, we explored the possible effect of the three BEST1 mutations p.V143F, p.S142G, and p.A146T on the apoptosis in human fetal RPE cells. METHODS: Wild-type plasmid and mutant plasmids BEST1-pcDNA3.1 p.V143F, p.S142G, and p.A146T were transfected to human fetal RPE cells. The molecules caspase-3, phospho-Bcl-2, BAX, PARP, and AIF associated with apoptosis were determined by quantitative PCR and Western blot. Apoptotic rate and active Caspase-3 staining were analyzed by flow cytometry. RESULTS:Caspase-3 and PARP expression were significantly increased in BEST1-pcDNA3.1 p.S142G and p.A146T group. Flow cytometry showed that the apoptosis rates were significantly increased in the BEST1-pcDNA3.1 p.V143F, p.S142G, and p.A146T group compared with the wild-type group. CONCLUSIONS: For the first time, we found that the three mutations promoted RPE cell apoptosis. Furthermore, the results indicated that BEST1 mutations p.S142G and p.A146T may contribute apoptosis of RPE cells by targeting Caspase 3. Our observations suggested that the apoptosis of RPE cells may be one of the mechanisms in bestrophinopathies, which may provide a new potential therapeutic target for the treatment of this disease.