Silence of lncRNA ANRIL represses cell growth and promotes apoptosis in retinoblastoma cells through regulating miR-99a and c-Myc.

Retinoblastoma is a rare cancer of the immature retina. This study designed to see the function of the lncRNA ANRIL in retinoblastoma Y79 cells. ANRIL, miR-99a and c-Myc expression in Y79 cells was altered by transfection and then trypan blue, transwell assay and flow cytometry were carried out to evaluate the changes of cell phenotype. The connection between ANRIL, miR-99a and c-Myc was measured by luciferase reporter assay and RNA immunoprecipitation analysis. As a result, ANRIL expression was highly expressed in human retinoblastoma tissue as relative to the adjacent noncancerous tissues. ANRIL suppression inhibited Y79 cells viability, migration, invasion, while promoted apoptosis. ANRIL negatively regulated miR-99a by binding to miR-99a. Silence of miR-99a reversed the ANRIL-knockdown effects on Y79 cells. miR-99a overexpression suppressed Y79 cell viability, migration, invasion, and enhanced apoptosis through downregulating c-Myc. Meanwhile, we found that miR-99a inhibited JAK/STAT and PI3K/AKT pathways. To conclude, it seems that ANRIL suppression inhibits cell growth and metastasis in retinoblastoma Y79 cells by regulating miR-99a and c-Myc.

Tetramethylpyrazine protects retinal ganglion cells against H2O2­induced damage via the microRNA­182/mitochondrial pathway.

Glaucoma is the leading cause of irreversible blindness worldwide; the apoptosis of the retinal ganglion cells (RGCs) is a hallmark of glaucoma. Tetramethylpyrazine (TMP) is the main active component of Ligusticum wallichii Franchat, and has been demonstrated to improve a variety of injuries through its antioxidative and antiapoptotic properties. However, these effects of TMP on glaucoma have not been studied. The present study aimed to investigate the potential role of TMP in glaucoma and to elucidate its possible mechanisms responsible for these effects. An in vitro model was generated, in which primary RGCs (PRGCs) were treated with H2O2. Our study revealed that TMP protected against H2O2­induced injury to PRGCs, as evidenced by enhanced cell viability, reduced caspase 3 activity and decreased cell apoptosis. We also reported that TMP treatment inhibited reactive oxygen species (ROS) production and malondialdehyde levels, but upregulated the antioxidative enzyme superoxide dismutase. In particular, TMP significantly increased the expression of microRNA­182­5p (miR­182) in H2O2­treated PRGCs, which was selected as the target miRNA for further research. In addition, our findings suggested that the protective effects of TMP on H2O2­induced injury were attenuated by knockdown of miR­182. The results of a luciferase reporter assay demonstrated that Bcl­2 interacting protein 3 (BNIP3), an effector of mitochondria­mediated apoptosis, was a direct target of miR­182. In addition, TMP treatment significantly decreased the expression of BNIP3, Bax, cleaved­caspase­3 and cleaved­poly(ADP­ribose)polymerase, but increased that of Bcl­2. Also, TMP treatment decreased the release of cytochrome c from mitochondria and improved mitochondrial membrane potential in H2O2­treated RGCs. Of note, the inhibitory effects of TMP on the mitochondrial apoptotic pathway were suggested to be reversed by knockdown of miR­182. Collectively, our findings provide novel evidence that TMP protects PRGCs against H2O2­induced damage through suppressing apoptosis and oxidative stress via the miR­182/mitochondrial apoptotic pathway.

Comprehensive Molecular Screening in Chinese Usher Syndrome Patients.

Purpose: Usher syndrome (USH) refers to a group of autosomal recessive disorders causing deafness and blindness. The objectives of this study were to determine the mutation spectrum in a cohort of Chinese patients with USH and to describe the clinical features of the patients with mutations. Methods: A total of 119 probands who were clinically diagnosed with USH were recruited for genetic analysis. All probands underwent ophthalmic examinations. A combination of molecular screening methods, including targeted next-generation sequencing, Sanger-DNA sequencing, and multiplex ligation probe amplification assay, was used to detect mutations. Results: We found biallelic mutations in 92 probands (77.3%), monoallelic mutations in 5 patients (4.2%), and 1 hemizygous mutation in 1 patient (0.8%), resulting in an overall mutation detection rate of 78.2%. Overall, 132 distinct disease-causing mutations involving seven USH (ABHD12, CDH23, GPR98, MYO7A, PCDH15, USH1C, and USH2A) genes; 5 other retinal degeneration genes (CHM, CNGA1, EYS, PDE6B, and TULP1); and 1 nonsyndromic hearing loss gene (MYO15A) were identified, and 78 were novel. Mutations of MYOA7 were responsible for 60% of USH1 families, followed by PCDH15 (20%) and USH1C (10%). Mutations of USH2A accounted for 67.7% of USH2 families, and mutation c.8559-2A>G was the most frequent one, accounting for 19.1% of the identified USH2A alleles. Conclusions: Our results confirm that the mutation spectrum for each USH gene in Chinese patients differs from those of other populations. The formation of the mutation profile for the Chinese population will enable a precise genetic diagnosis for USH patients in the future.

A polysaccharide from green tea (Camellia sinensis L.) protects human retinal endothelial cells against hydrogen peroxide-induced oxidative injury and apoptosis.

Oxidative damage of retinal pigment epithelium (RPE) cells is involved in the pathogenesis age related macular degeneration (AMD). The purpose of this study was to evaluate the potential protective effect of a purified green tea polysaccharide (GTWP) against hydrogen peroxide (H2O2) induced oxidative stress and apoptosis in human retinal pigment epithelial cells (ARPE-19 cells). Human ARPE-19 cells were treated with 1 h of 500 µM H2O2 before incubation with GTWP for 24 h. Pretreatment of GTWP decreased H2O2-induced cell death and cell apoptosis, and efficiently suppressed the intracellular ROS production and malondialdehyde (MDA) generation induced by H2O2 treatment. Moreover, a loss of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione (GSH) activities were restored to normal level in H2O2-induced ARPE-19 cells upon GTWP (100 µg/ml) exposure. Also, the tendency of increased protein expression of Bax and cleaved-caspsae-3, as well as decrease of Bcl-2 protein in ARPE-19 cells challenged with H2O2 was changed to individual opposite way, thus inhibiting the apoptotic cell death. Our results demonstrated that GTWP protected RPE cells against oxidative injury through activation of anti-apoptotic and endogenous antioxidant enzymes signaling pathway, suggesting GTWP has attractive therapeutic potential to AMD.

Mutation screening of mitochondrial DNA as well as OPA1 and OPA3 in a Chinese cohort with suspected hereditary optic atrophy.

PURPOSE: Leber's hereditary optic atrophy (LHON) and autosomal dominant optic atrophy (DOA) are the two most common forms. The objective of this study was to define the fractional prevalence of LHON and DOA in a cohort of Chinese patients with suspected hereditary optic neuropathy. METHODS: We recruited 520 unrelated patients with bilateral optic atrophy for genetic analysis: 174 patients had a positive family history of visual failure and 346 were sporadic cases. A total of 14 primary LHON-causing mtDNA mutations was screened by PCR-based sequencing methods for all patients except the individuals with a paternal family history. All coding exons and exon-intron boundaries of the OPA1 and OPA3 gene were screened for mutations by PCR-based DNA sequencing for all patients with paternal family history and for the LHON-negative patients. A large genomic DNA arrangement of the OPA1 gene was detected further by multiplex ligation probe amplification (MLPA) assay for the patients with paternal family history, but results were negative for the OPA1 and OPA3 mutation screenings. RESULTS: We found molecular defects in 323 (62%) of the 520 probands screened. Among these, 271 patients (83.9%) had an mtDNA mutation, 50 patients (15.5%) carried an OPA1 mutation, and 2 patients (0.6%) had an OPA3 mutation. Coexistence m.3460 G>A and m.11778G>A was found in one patient. We identified 40 intragenic mutations and six large genomic DNA arrangements of the OPA1 gene, 23 of which were novel. CONCLUSIONS: The LHON-mtDNA mutations are the most common genetic defects, followed by the OPA1 mutations, in this Chinese cohort.

A novel GUCY2D mutation in a Chinese family with dominant cone dystrophy.

PURPOSE: To describe the clinical and genetic findings in a Chinese family with autosomal dominant cone dystrophy (adCOD). METHODS: One family was examined clinically, and genomic DNA was extracted from venous blood of all participants. Genotyping and haplotyping analysis was performed on the known genetic loci for adCOD and autosomal dominant cone-rod dystrophies (adCORD) with a panel of polymorphic markers in this family. All coding exons of the AIPL1, PTTPNM3, and GUCY2D gene were directly sequenced. Allele-specific PCR was used to validate a substitution in all available family members and 100 normal controls. Bioinformatics analysis was done using the Garnier-Osguthorpe-Robson method to predict the effect of the variants detected on the secondary structure of the GUCY2D protein. RESULTS: Clinical examination and pedigree analysis revealed a three-generation family with four members diagnosed with adCOD. Through genotyping, the disease-causing genes were mapped to chromosomes 17p13.1-2 (AIPL1, PITPNM3, and GUCY2D gene). A novel A->G transition at position 2545 (p.T849A) of the cDNA sequence was identified in the GUCY2D gene. No mutation was detected in the AIPL1 and PITPNM3 genes. This missense mutation co-segregated with the disease phenotype of the family but was not found in the 100 normal controls. CONCLUSIONS: A novel missense mutation of the GUCY2D gene was identified in this study. Our results further confirm that the dimerization zone of RetGC-1 is the mutational hot region for COD and CORD.