ABSTRACT
Objective:To analyze the clinical phenotypes and pathogenic gene of a Han Chinese family with enhanced S-cone syndrome (ESCS).Methods:The method of pedigree investigation was adopted.A suspected ESCS Han Chinese family including 8 members of 3 generations was recruited in Henan Eye Hospital from June to September 2021.There was one patient in the family.A thorough ophthalmic examination of the proband was carried out to evaluate the phenotypes, including visual acuity, degree of strabismus, anterior segment and fundus, autofluorescence imaging, fluorescein fundus angiography, full-field electroretinogram (ERG), multifocal ERG, optical coherence tomography.DNA was extracted from peripheral blood samples from the proband and family members.The pathogenic gene and variation were screened by whole exome sequencing (WES).The variation and co-segregation were verified by Sanger sequencing.The deleteriousness of the variation was analyzed by SIFT, Polyphen2 and MutationTaster.The pathogenicity of the variation was evaluated in accordance with the American College of Medical Genetics and Genomics (ACMG) Standards and Guidelines.The analysis of amino acid sequence conservation was performed by SIFT.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Henan Eye Hospital (No.HNEECKY-2017[6]).Written informed consent was obtained from each subject.Results:This pedigree was consistent with autosomal recessive inheritance.The proband had clinical features such as night blindness, hyperopia, accommodative esotropia, peripheral retinal pigmentation, retinoschisis, and photopic ERG responses dominated by large-amplitude waves.Variations including a compound heterozygous variation, c.671C>T: p.S224L on exon 5 and c. 955G>A: p.E319K on exon 6 of NR2E3 were identified by WES.The variations were confirmed to be consistent with co-segregation.The both loci were missense variations, the variation frequency of which was 0 in the East Asian population via the gnomAD database.The variations were predicted to be deleterious by SIFT, Polyphen2 and MutationTaster.The c.671C>T variation was recorded with unknown significance in ClinVar database, and the c.955G>A variation was an unreported new locus.According to the ACMG Standards and Guidelines, the both variations were labeled as with uncertain clinical significance, and the corresponding amino acid sequences were highly conservative across multiple species. Conclusions:This family has the clinical characteristics of ESCS and meets the genetic diagnosis criteria.Two novel variations in NR2E3 gene, c.671C>T: p.S224L and 955G>A: p.E319K, are found.
ABSTRACT
Objective:To investigate the anti-oxidative stress effects of microRNA 125b (miR-125b) on lens epithelial cells (LECs) and its possible mechanism.Methods:Twenty-four anterior capsule specimens were collected from 24 eyes of 24 age-related cataract patients during phacoemulsification and 20 normal anterior capsule specimens were obtained from 20 eyes of 20 donors in Henan Eye Hospital from July 2018 to March 2019 under the approval of a Medical Ethics Committee of Henan Eye Hospital (No.YKYY20193151).The reverse transcription PCR and Western blot assay were employed to detect and compare the relative expression levels of miR-125b and nuclear factor E2-related factor 2 (Nrf2) in different specimens.The human lens epithelial cell line HLEB-3 was divided into control group and oxidative stress model group.The oxidative stress models were established by coculture with different concentrations (100, 200, 400 μmol/L) of H 2O 2 for 24 hours, and the cells were cultured with normal medium without H 2O 2 in the control group.The reactive oxygen species (ROS) content was detected by DCFH-DA fluorescent probe, and the activities of total-antioxidative capability (T-AOC), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) as well as malondialdehyde (MDA) concentration were detected by ELISA, and compared among the groups.The expression levels of miR-125b and Nrf2 were detected by reverse transcription PCR and Western blot assay, respectively.The cells were transfected with miR-125b mimics, miR-125b control and miR-125b inhibitor for 24 hours, respectively, and ROS content was detected by DCFH-DA fluorescent probe and T-AOC, SOD and GSH-Px activities as well as MDA concentration were detected by ELISA and compared among different transfected groups.A dual luciferase reporter assay was used to assess an association between miR-125b and Nrf2.The expression level of Nrf2 protein was detected by Western blot assay and the expression levels of Nrf2 and Keap1 were assayed and located by immunofluorescence double staining. Results:The relative expression levels of miR-125b and Nrf2 in the normal lens anterior capsule specimens were 0.21±0.03 and 0.27±0.06, which were significantly lower than 0.89±0.05 and 0.84±0.12 in the cataract specimens, respectively ( t=15.355, P<0.05; t=18.647, P<0.05).The relative expression levels of miR-125b and Nrf2 were significantly increased in various H 2O 2 treated groups in comparison with the control group and were gradually elevated with the increase of H 2O 2 concentration (all at P<0.05).Compared with the control group, the T-AOC, SOD and GSH-Px activities were reduced, and ROS content and MDA concentration were significantly ascended (all at P<0.05).Compared with the miR-125b control group, the T-AOC, GSH-Px and SOD activities were increased, and ROS content and MDA concentration were decreased in the miR-125b mimics group (all at P<0.05).In addition, the T-AOC, GSH-Px and SOD activities were significantly weakened, and ROS content and MDA concentration were significantly increased in the miR-125b inhibitor group in comparison with the miR-125b control group (all at P<0.05).Dual luciferase reporter assay showed that miR-125b targeted to the expression of Nrf2 in the H 2O 2 model cells.The fluorescence of Nrf2 in the cytoplasm was the strongest with more nuclear transfer in the miR-125b mimics group, and the expression intensity of Keap1 in the cytoplasm was weaker.The expression of Nrf2 was the weakest with less nuclear transfer in the miR-125b inhibitor group, and the expression level of Keap1 in the cytoplasm was stronger. Conclusions:MiR-125b can enhance the anti-oxidative stress of LECs in age-related cataractous eyes probably by upregulating the expression of Nrf2 and activating the Keap1/Nrf2 signaling pathway.