Circ-CARD6 inhibits oxidative stress-induced apoptosis and autophagy in ARPE-19 cells via the miR-29b-3p/PRDX6/PI3K/Akt axis.

BACKGROUND: Oxidative stress-induced damage and dysfunction of retinal pigment epithelium (RPE) cells are important pathogenetic factors of age-related macular degeneration (AMD) and hereditary retinopathy diseases (HRDs). This study aimed to elucidate the roles and mechanisms of circ-CARD6 and miR-29b-3p in oxidative stress-induced RPE and provide new ideas for the diagnosis and treatment of retinopathy disease (RD). METHODS: A model of oxidative stress-induced RPE (ARPE-19) was established, and the level of malondialdehyde (MDA) and concentration of reactive oxygen species (ROS) were detected by a DCFH-DA fluorescent probe and MDA kit. The cell viability was measured by a CCK-8 assay. The expression of PRDX6/PI3K/Akt axis genes and proteins related to apoptosis and autophagy were determined by RT‒qPCR and Western blot analyses. The dual-luciferase reporter system confirmed the targeting relationship between miR-29b-3p and circ-CARD6 and between miR-29b-3p and PRDX6. RESULTS: In H2O2-treated ARPE-19 cells, the expression of circ-CARD6 and PRDX6 was decreased, while the expression of miR-29b-3p was increased. The overexpression of circ-CARD6 inhibits oxidative stress-induced increases in ROS, apoptosis and autophagy in ARPE-19 cells. circ-CARD6 targets miR-29b-3p, miR-29b-3p targets PRDX6, and circ-CARD6 regulates PRDX6 via miR-29b-3p. Further studies showed that circ-CARD6 acts as a competitive endogenous RNA of miR-29b-3p to affect the expression of PRDX6, thereby inhibiting autophagy and apoptosis in ARPE-19 cells. CONCLUSION: circ-CARD6 can inhibit oxidative stress and apoptosis by regulating the miR-29b-3p/PRDX6/PI3K/Akt axis.

A novel missense mutation in the CRYBA2 caused autosomal dominant presenile cataract in a Chinese family.

Presenile cataract is a relatively rare type of cataract, but its genetic mechanisms are currently not well understood. The precise identification of these causative genes is crucial for effective genetic counseling for patients and their families. The aim of our study was to identify the causative gene associated with presenile cataract in a Chinese family. In February 2020, a four-generation pedigree of presenile cataract patients was recruited at the 2nd Affiliated Hospital of Kunming Medical University. One patient and her healthy husband from the family underwent whole exome sequencing. The variant was validated through sanger sequencing, and co-segregation analysis was conducted in all family members to assess its pathogenicity. Molecular dynamics simulation (MDS) was used to analyze the conformation of both the wild type and pathogenic mutant loci p.Y153H of CRYBA2. We identified presenile cataract in the pedigree, which follows an autosomal-dominant pattern of inheritance. The family includes five clinically affected patients who all developed presenile cataract between the ages from 24 to 30. We confirmed the pathogenicity of a heterozygous missense variant (NM_057093:c.457T >C) in CRYBA2 within this family. The affected amino acid demonstrates high conservation across species. Subsequent sanger sequencing confirmed co-segregation of the disease in all family members. MDS analysis revealed that the p.Y153H mutant disrupted hydrogen bond formation between Y153 and R193 within the two ß-strands of the fourth Greek key domain, leading to destabilization of the ßA2-crystallin. In conclusion, a novel causative mutation (NM_057093:c.457T>C) in CRYBA2 might contribute to autosomal dominant presenile cataract.

A novel nonsense mutation in ADAMTS17 caused autosomal recessive inheritance Weill-Marchesani syndrome from a Chinese family.

Weill-Marchesani syndrome (WMS) is a rare connective tissue disorder characterized by short stature, brachydactyly, joint stiffness, eye anomalies, including microspherophakia, ectopia of the lenses, severe myopia, glaucoma and occasionally heart defects. Given these complex clinical manifestations and genetic heterogeneity, WMS patients presented misdiagnosed as high myopia or angle closure glaucoma. Here, we report ADAMTS17 mutations, a member of the extracellular matrix protease family, from a Chinese family. Patients have features that fall within the WMS spectrum. The exome (protein-coding regions of the genome) makes up ~1 % of the genome, it contains about 85% of known disease-related variants. Whole exome sequencing (WES) has been performed to identify the disease-associated genes, including one patient, his healthy sister, and his asymptomatic wife. Genome-wide homozygosity map was used to identify the disease caused locus. SNVs and INDELs were further predicted with MutationTaster, LRT, SIFT and SiPhy and compared to dbSNP150 and 1000 Genomes project. Filtered mutation was confirmed with Sanger sequencing in whole family members. The Genome-wide homozygosity map based on WES identified a total of 20 locus which were possible pathogenic. Further, a novel nonsense mutation c.1051A >T result in p.(lys351Ter) in ADAMTS17 had been identified in a candidate loci. The Sanger sequencing data has verified two consanguineous WMS patients in the family pedigree and revealed autosomal recessive (AR) inheritance pattern. The nonsense mutation in ADAMTS17 was analyzed in silico to explore its effects on protein function. We predicted the mutation produced non-function protein sequence. A novel nonsense mutation c.1051 A > T in ADAMTS17 had been identified caused autosomal recessive WMS in the Chinese family.