Gut microbiota induced abnormal amino acids and their correlation with diabetic retinopathy.

AIM: To explore the correlation of gut microbiota and the metabolites with the progression of diabetic retinopathy (DR) and provide a novel strategy to elucidate the pathological mechanism of DR. METHODS: The fecal samples from 32 type 2 diabetes patients with proliferative retinopathy (PDR), 23 with non-proliferative retinopathy (NPDR), 27 without retinopathy (DM), and 29 from the sex-, age- and BMI- matched healthy controls (29 HC) were analyzed by 16S rDNA gene sequencing. Sixty fecal samples from PDR, DM, and HC groups were assayed by untargeted metabolomics. Fecal metabolites were measured using liquid chromatography-mass spectrometry (LC-MS) analysis. Associations between gut microbiota and fecal metabolites were analyzed. RESULTS: A cluster of 2 microbiome and 12 metabolites accompanied with the severity of DR, and the close correlation of the disease progression with PDR-related microbiome and metabolites were found. To be specific, the structure of gut microbiota differed in four groups. Diversity and richness of gut microbiota were significantly lower in PDR and NPDR groups, than those in DM and HC groups. A cluster of microbiome enriched in PDR group, including Pseudomonas, Ruminococcaceae-UCG-002, Ruminococcaceae-UCG-005, Christensenellaceae-R-7, was observed. Functional analysis showed that the glucose and nicotinate degradations were significantly higher in PDR group than those in HC group. Arginine, serine, ornithine, and arachidonic acid were significantly enriched in PDR group, while proline was enriched in HC group. Functional analysis illustrated that arginine biosynthesis, lysine degradation, histidine catabolism, central carbon catabolism in cancer, D-arginine and D-ornithine catabolism were elevated in PDR group. Correlation analysis revealed that Ruminococcaceae-UCG-002 and Christensenellaceae-R-7 were positively associated with L-arginine, ornithine levels in fecal samples. CONCLUSION: This study elaborates the different microbiota structure in the gut from four groups. The relative abundance of Ruminococcaceae-UCG-002 and Parabacteroides are associated with the severity of DR. Amino acid and fatty acid catabolism is especially disordered in PDR group. This may help provide a novel diagnostic parameter for DR, especially PDR.

Retracted Article: LncRNA KCNQ1OT1 Promotes Apoptosis and Oxidative Stress of Human Lens Epithelial Cells through Epigenetic Regulation of WRN.

We, the authors, Editors and Publisher of the journal Current Eye Research, have retracted the following article:Shengqun Jiang, Yanwen Jia and Ziqing Gao. LncRNA KCNQ1OT1 promotes apoptosis and oxidative stress of human lens epithelial cells through epigenetic regulation of WRN. Current Eye Research 2022; [2022 Feb 18;1-25; Online ahead of print]. doi.org/10.1080/02713683.2022.2026975.Since publication, the authors have informed the journal that they are unable to provide the original data for the study and are unable to verify the findings after failing to reproduce the results. As this directly impacts the validity of the reported results and conclusions, the authors alerted the issue to the Editors and Publisher and all have agreed to retract the article to ensure the integrity of the scholarly record.We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions.The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as "Retracted."

The efficacy and safety of intravitreal conbercept combined with mitomycin C augmented trabeculectomy for treating neovascular glaucoma.

AIM: To investigate the efficacy and safety of intravitreal Conbercept (IVC) and trabeculectomy for treating neovascular glaucoma (NVG). METHODS: We retrospectively reviewed a total of 29 eyes from 29 NVG patients. All patients received preoperative IVC combined with mitomycin C (MMC) augmented trabeculectomy with a 12-month follow-up. The best-corrected visual acuities (BCVA), intraocular pressure (IOP), and cumulative survival rate were calculated. RESULTS: All 29 cases had complete regression of iris neovascularization at 7 days after the combination treatment, and 2 cases had residual iris neovascularization which regressed completely 1 month later. IOP decreased while BCVA improved significantly following the combination treatment. The success rates were 96.6%, 93.1%, 89.7%, 86.2%, and 82.8% at 1 week, 1, 3, 6, and 12 months after trabeculectomy, respectively. IVC injection combined trabeculectomy had few complications. CONCLUSIONS: IVC injection of conbercept combined with trabeculectomy is effective and safe for the treatment of NVG.

WRN inhibits oxidative stress-induced apoptosis of human lensepithelial cells through ATM/p53 signaling pathway and its expression is downregulated by DNA methylation.

BACKGROUND: Apoptosis and oxidative stress are the main etiology of age related cataract (ARC). This article aims to investigate the role of WRN in lens epithelial cells (LECs). METHODS: We estimated the methylation level of WRN in anterior lens capsule tissues of ARC patients. SRA01/04 (LECs) cells were treated with H2O2 or combined with 5-aza-2-deoxycytidine (5-Aza-CdR) or chloroquine. CCK8 and flow cytometry were performed to explore proliferation and apoptosis. The content of ROS was detected by fluorescent probe DCFH-DA. The gene and protein expression was assessed by quantitative real-time PCR or western blot. RESULTS: WRN was down-regulated and the methylation level of WRN was increased in the anterior lens capsule tissues. WRN overexpression and 5-Aza-CdR enhanced proliferation and repressed apoptosis and oxidative stress of SRA01/04 cells. 5-Aza-CdR enhanced WRN expression. WRN knockdown inhibited proliferation and promoted apoptosis and oxidative stress of SRA01/04 cells, which was rescued by 5-Aza-CdR. WRN overexpression and 5-Aza-CdR repressed ATM/p53 signaling pathway. Furthermore, chloroquine inhibited proliferation and promoted apoptosis and oxidative stress of SRA01/04 cells by activating ATM/p53 signaling pathway. The influence conferred by chloroquine was abolished by WRN overexpression. CONCLUSION: Our study reveals that DNA methylation mediated WRN inhibits apoptosis and oxidative stress of human LECs through ATM/p53 signaling pathway.

LncRNA NBAT1 suppresses cell proliferation and migration via miR-346/GSK-3ß axis in renal carcinoma.

Long non-coding RNA (LncRNA) neuroblastoma associated transcript 1 (NBAT1) was demonstrated to be significantly downregulated in renal carcinoma (RCC) cells. However, the function and mechanism of NBAT1 in RCC is poorly understood. The expression of NBAT1 and glycogen synthase kinase-3ß (GSK-3ß)-mediated Wnt/ß-catenin-related proteins were measured by quantitative real-time PCR (qRT-PCR) and western blotting in RCC cell lines. Cell viability, migration, and invasion were estimated by CCK-8 and Transwell assay. The association of miR-346 with GSK-3ß expression was verified using luciferase assay. NBAT1 was significantly downregulated in RCC cells, and inhibited RCC cell proliferation, migration, and invasion. Furthermore, NBAT1 negatively regulated miR-346 expression. In addition, miR-346 overexpression and the knockdown of GSK-3ß, a direct target of miR-346 could overturn the inhibitory effect of NBAT1 on Wnt/ß-catenin signaling and cell proliferation, migration, and invasion. NBAT1 functioned as an endogenous sponge by competing for miR-346 binding to GSK-3ß and therefore alleviated RCC cells.

Caffeic acid phenethyl ester attenuates nuclear factor­κB­mediated inflammatory responses in Müller cells and protects against retinal ganglion cell death.

Glaucoma is characterized by the death of retinal ganglion cells (RGCs) and visual field defects, and is a leading cause of blindness worldwide. Caffeic acid phenethyl ester (CAPE), a natural polyphenolic found in propolis from honeybee hives, can inhibit the activation of nuclear factor κ light­chain­enhancer of activated B cells (NF­κB) and has therapeutic potential in inflammatory disease. The present study used a rat model of optic nerve crush (ONC) injury to investigate the effect of CAPE on glaucoma. The death of RGCs at day 14 was significantly reduced in CAPE­treated animals compared with the non­treated group according to Brn3a and TUNEL staining. In addition, CAPE decreased the severity of inflammation in the retina, reflected by the decreased expression of inflammatory cytokines, including interleukin (IL)­8, IL­6, inducible nitric oxide synthase, cycloooxygenase­2, tumor necrosis factor­α and chemokine C­C ligand­2, in CAPE­treated rats. The hypertrophy of astrocytes and Müller cells (gliosis) caused by ONC was also found to be attenuated by CAPE, accompanied by the inhibition of NF­κB signaling. Similarly, in vitro, CAPE suppressed the proliferation and migration of primary astrocytes induced by lipopolysaccharide, as well as the activation of NF­κB. These results suggest that CAPE protected against RGC and attenuated inflammatory responses in a rat model of ONC by suppressing NF­κB activation.

Decreased expression of BRAF-activated long non-coding RNA is associated with the proliferation of clear cell renal cell carcinoma.

BACKGROUND: BRAF-activated long non-coding RNA (BANCR) has been associated with various types of cancer. Nevertheless, the role of BANCR in clear cell renal cell carcinoma (ccRCC) is still not fully understood. This study aims to investigate the relationship between ccRCC and BANCR. METHODS: Expression of BANCR in TCGA renal cancer data sets was analyzed. The expression pattern of BANCR in Immortalized normal human proximal tubule epithelial cell line HK-2 and ccRCC cell lines (ACHN, CAKI-1, A498 and 786-O) was detected by real-time quantitative RT-PCR (qRT-PCR). ccRCC tissues with adjacent normal renal tissues diagnosed by pathological methods from 62 patients were used to detect the expression of BANCR, and its correlation with prognosis of ccRCC patients was assessed by Kaplan-Meier method. The LV-BANCR vector was used to examine the influence of BANCR on the proliferation, migration, invasion, apoptosis and cell cycle distribution of ccRCC cells in vitro. RESULTS: BANCR was downregulated in renal cancer according to TCGA data sets. Compared with adjacent normal renal tissues and normal human proximal tubule epithelial cell line HK-2, BANCR expression was significantly decreased in ccRCC tissues and ccRCC cell lines, and its low expression was associated with poor prognosis. Moreover, in the condition of BANCR overexpression by LV-BANCR vector, the proliferation, migration, invasion capacity of ccRCC cells was inhibited, while the apoptosis was increased and the G1 cell cycle arrest was induced in vitro. CONCLUSIONS: BANCR is downregulated in ccRCC tissues and cell lines, and is associated with ccRCC progression. Thus, BANCR may represent a novel prognostic biomarker and a potential therapeutic target for ccRCC patients.

Copy number variations of DNA repair genes and the age-related cataract: Jiangsu Eye Study.

PURPOSE: DNA damage is critical in the pathogenesis of age-related cataract (ARC). This study examined the association of copy number variations (CNVs) of DNA repair genes with susceptibility to ARC in the Han Chinese. METHODS: Study participants were from the population-based Jiangsu Eye Study, which includes 780 ARC patients and 525 controls. DNA was extracted from blood for copy number (CN) assays using RT-PCR. The Comet assay was to assess DNA damage in peripheral lymphocytes. RESULTS: Novel CNV was detected in WRN. Initial analyses found that CN = 3+ for WRN had an increased risk of ARC (odds ratio [OR] = 1.88, P = 0.02); CN = 1 for HSF4 had an increased risk of ARC (OR = 4.09, P = 0.004). CN = 3+ for WRN was associated with nuclear and posterior subcapsular cataract (OR = 2.06, P = 0.02; OR = 3.72, P = 0.02). CN = 1 for HSF4 was associated with nuclear and posterior subcapsular cataract (OR = 5.73, P = 0.001; OR = 6.80, P = 0.01). The combination WRN and HSF4 CNVs markedly increased the risk of ARC; the OR was increased from 2.63 by HSF4 alone to 6.80 by combined WRN and HSF4 CNVs. However, after multiple testing correction, only HSF4 CNV was associated with ARC overall and with nuclear and posterior subcapsular cataract as well. The DNA damage in lymphocytes from ARC patients was significantly higher when compared to normal controls. CONCLUSIONS: HSF4 and WRN CNVs might be involved in ARC pathogenesis in the Han Chinese. These findings suggest the importance of DNA repair in ARC susceptibility and distinct risk factors in ARC subtypes.

Polymorphisms of the WRN gene and DNA damage of peripheral lymphocytes in age-related cataract in a Han Chinese population.

Werner syndrome is caused by mutations in the DNA repair Werner helicase (WRN) gene and characterized by accelerated aging including cataracts. Age-related cataract (ARC) cases (N = 504) and controls (N = 244) were recruited from a population-based study to evaluate the association of single-nucleotide polymorphisms (SNPs) of WRN and another DNA repair gene (human 8-oxoguanine DNA N-glycosylase 1) with ARC. Among the five SNPs tested, only WRN rs1346044 was found to be significantly associated between cases and controls before multiple-testing adjustment. The minor C allele of rs1346044 was associated with ARC with an odds ratio (OR) of 0.66, suggesting a protective role of the C allele for developing ARC. The stratification analysis on the subtypes of ARC showed that rs1346044 was significantly associated with cortical cataract, but not with nuclear, posterior subcapsular, and mixed types after multiple-testing adjustment (OR = 0.51, p< 0.01). The genetic model analysis showed that the results fit the dominant model (OR = 0.44, p < 0.001). The comet assay used to assess the extent of DNA damage in peripheral lymphocytes of ARC cases found that the DNA damage in lymphocytes from patients with CC genotype was significantly less than that in patients with TT genotype. We concluded that the C allele of rs1346044, a non-synonymous SNP resulting in the conversion of Cys to Arg at amino acid position 1367 of WRN, alters susceptibility to ARC, especially the cortical type of the disease, in the Han Chinese. The underlying mechanism of its protective role might be related to the improved DNA repair function.

The associations between single nucleotide polymorphisms of DNA repair genes, DNA damage, and age-related cataract: Jiangsu Eye Study.

PURPOSE: Age-related cataract (ARC) is one of the most common causes of severe visual impairment among the elderly worldwide with four subtypes, such as cortical, nuclear, subcapsular, and mixed types. DNA damage and malfunction of DNA repair are believed to contribute to the pathogenesis of ARC. This study examined the associations of 18 single nucleotide polymorphisms (SNPs) in four DNA repair genes (BLM, WRN, ERCC6, and OGG1) with ARC in Han Chinese from the Jiangsu Eye Study, a population-based epidemiologic study. We also determined the possible functional consequence of the SNPs to DNA damage. METHODS: Eighteen SNPs in four DNA repair genes were genotyped in 789 ARC patients and 531 normal controls from the Jiangsu Eye Study. The Comet assay was to assess the extent of DNA damage in peripheral lymphocytes of selected subjects. RESULTS: The results show that WRN-rs11574311 was initially associated with ARC in general, cortical, and mixed cataracts (P = 0.003, odds ratio [OR] = 1.49; P = 0.001, OR = 1.68; and P < 0.0001, OR = 2.08), BLM-rs1063147 with nuclear cataract (P = 0.03, OR = 1.31), WRN-rs2725383 with cortical cataract (P = 0.01, OR = 1.49), and WRN-rs4733220 and WRN-rs2725338 with mixed cataract (P = 0.04, OR = 0.74; P = 0.003, OR = 0.60). However, the significances of some of the above-cited associations disappeared after multiple testing corrections. WRN-rs11574311 remains associated with cortical and mixed cataract and WRN-rs2725338 with mixed cataract after multiple testing correction. We did not find any correlation between DNA damage of peripheral lymphocytes and SNP types. CONCLUSIONS: We concluded that WRN genes might be involved in ARC pathogenesis in the Han Chinese population. The associations were ARC subtype specific. These findings stress the importance of detailed phenotyping in ARC subtypes, which may be associated with different risk factors and disease mechanisms.