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Purpose We aim to reveal the disease-causing mutations in 15 Chinese families with optic atrophy (OA). Methods In total, 15 families with OA were recruited in the present study. Medical histories were carefully reviewed and comprehensive ophthalmic examinations were received by all recruited patients. Targeted next-generation sequencing (NGS) was selectively performed on all probands for mutation detection. Intrafamilial cosegregation and in-silico analyses were subsequently applied to predict the potential pathogenic effects of identified mutations. Results All included patients presented bilateral vision loss. Their fundus photographs showed temporal or total pallor of the optic discs. Fourteen mutations in the optic atrophy 1 (OPA1) gene were revealed as disease-causing mutations for the 15 families, including eight novel (c.968A>G, c.193C>G, c.1071dupT, c.987_988del, c.2012+2T>G, c.1036–1G>C, c.2126A>G, and c.1036_1038del) and six recurrent (c.1499G>A, c.1800C>A, c.1034G>A, c.2873_2876del, c.112C>T, and c.804_805del) mutations. Conclusions In conclusion, our study expands the mutational spectrum for the OPA1 gene and implies targeted NGS as an effective approach for the genetic diagnosis of OA, which might help to improve the clinical diagnosis for patients with OA.

Purpose To investigate the role of Gremlin-1, which is an endogenous antagonist of the bone morphogenetic protein (BMP) signaling pathway, in inducing epithelium-mesenchymal transition (EMT) in fetal RPE cells after repeated wounds. Methods Subconfluent repetitive passages in fetal RPE cells were regarded as a model of repeated wounds. A phase contrast microscope was used to observe the morphology and pigment formation in cells. The expression of GREM1 (Gene ID: 26585; OMIM 603054) and EMT- or RPE-related genes in cells was evaluated with quantitative PCR (qPCR). Recombinant human protein Gremlin-1 (0.1 μg/ml) was added every day to investigate the molecular effects of Gremlin-1 on fetal RPE cells. The cell migration rate was investigated using a cell wound scratch assay, and western blotting was used to analyze the representative proteins (P-cadherin, ZO-1, vimentin, Smad4, and phosphorylated-Smads). In addition, transfection of siRNA was used to explore the rescue effects on EMT cells through the downregulation of GREM1. Finally, LDN193189, which is a type of pan-inhibitor of BMP receptors, was used to verify whether complete blocking of the BMP pathway interferes with the redifferentiation in low-passage fetal cells, even if the cells were treated with transforming growth factor beta 1 (TGF-β) inhibitors. Results In fetal RPE cells, the expression of GREM1 were gradually upregulated with repetitive passages, and at the same time, the function-specific genes in fetal RPE cells (TJP1, PMEL, BEST1, RPE65, and MERTK) were downregulated while the EMT-specific genes were upregulated. In addition, GREM1 had a similar expression pattern as SNAI1, which is a key transcription factor to trigger EMT. Recombinant human Gremlin-1 promoted EMT with the upregulation of SNAI1 and elevated the cell migration rate in a cell scratch assay, as well as decreased the expression of two key transcription factors of RPE embryonic development (MITF and OTX2) and the RPE marker, RPE65. Furthermore, the EMT marker, vimentin, and the TGF-β pathway downstream transcription factor phosphorylated-Smad2 (p-Smad2) increased, but the epithelial marker, ZO-1, was reduced. Additionally, Smad4, which plays a role as a Snail1 cooperator by binding Smad3, was also increased. In contrast, GREM1 silencing increased the expression of MITF and OTX2, which means there was better redifferentiation in subconfluent fetal RPE cells, but it had little influence on p-Smad2 compared to the negative control group. Finally, by adding LDN193189, the BMP signaling pathway was blocked, and this block led to poor redifferentiation in low-passage cells, although the cells were treated with TGF-β inhibitors. In addition, as positive feedback to block the BMP pathway, GREM1 was subsequently upregulated. Conclusions In fetal RPE cells, Gremlin-1 induces EMT and inhibits redifferentiation by promoting the TGF-β pathway and inhibiting the BMP pathway. GREM1 silencing alleviates EMT and increases the redifferentiation of cells by relieving the blockade of the BMP pathway. However, GREM1 silencing has no effects on the TGF-β pathway. Thus, Gremlin-1 may serve as a novel target to treat proliferative vitreoretinopathy (PVR) and inhibit subretinal fibrosis, which is a risk factor for influencing the therapeutic effects of anti-vascular endothelial growth factor (anti-VEGF) on neovascular age-related macular degeneration (nAMD).

Purpose The aim of this study was to assess the roles of plasma cytokines in diabetic retinopathy (DR) and their relationship with the severity of DR. Methods This study included 59 diabetic patients and 19 non-diabetic controls. The plasma concentrations of endothelial growth factor (EGF), eotaxin, fibroblast growth factor 2 (FGF-2), Flt-3 ligand (Flt-3L), fractalkine, granulocyte colony-stimulating factor (G-CSF), granulocyte–macrophage colony-stimulating factor (GM-CSF), growth-related oncogene (GRO), interferon (IFN)-α2, IFN-γ, interleukin (IL)-1α, IL-1β, IL-1Ra, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12 (p40), IL-12 (p70), IL-13, IL-15, IL-17, IFN-inducible protein-10 (IP-10), monocyte chemoattractant protein (MCP)-1, MCP-3, macrophage-derived cytokine (MDC), macrophage inflammatory protein (MIP)-1α, MIP-1β, sCD40L, sIL-2Rα, transforming growth factor (TGF)-α, tumor necrosis factor (TNF)- α, TNF-β, and VEGF were measured with Luminex multiplex bead immunoassay. The levels of these cytokines were investigated according to the DR stage. Results The plasma level of ten cytokines—MCP-1, IL-6, IL-7, IL-9, IL-13, IL-15, IL-17, sCD40L, sIL-2Rα and TNF-β—increased significantly in the diabetic group compared to the controls. The Flt-3L, IL-1Ra, IL-3, IL-5, and IL-12 (p40) levels were lower in the diabetic group than in the control group. The TNF-α plasma level was significantly elevated in patients with proliferative diabetic retinopathy (PDR) compared with the levels in patients with non-proliferative diabetic retinopathy (NPDR) and patients with no apparent diabetic retinopathy (NDR). Conclusions TNF-α might be involved in the progression of DR, especially in the pathogenesis of PDR. TNF-α is a potential cytokine for the prognosis of DR and might act as a therapeutic target in DR.

Purpose To identify the causative mutation with its possible origin in a Chinese family with congenital fibrosis of extraocular muscles type 1 (CFEOM1) and to characterize the ocular phenotypes and lesions in the corresponding intracranial nerves. Methods Three affected siblings and their asymptomatic parents underwent comprehensive ophthalmic examinations and neuropathologic analysis involving magnetic resonance imaging (MRI). KIF21A, PHOX2A, and TUBB3 genes were sequenced on the leukocyte-derived DNA to detect variants. The disease-linked haplotype was analyzed using four microsatellite markers across the KIF21A locus. Results All three affected individuals displayed typical CFEOM1. MRI revealed complicated but consistent neuromuscular abnormalities in the two patients examined, including hypoplastic oculomotor nerves, complete absence of bilateral superior rectus muscles, and unilateral absence of the abducens nerve with marked atrophy of the corresponding lateral rectus muscle. A heterozygous hotspot mutation KIF21A c.2860C>T was identified in all patients, but it was absent in both parents. Haplotype analysis of the disease locus showed the likely maternal inheritance of the disease-associated haplotype to all three affected offspring, strongly suggesting maternal germline mosaicism of the mutation. Conclusions Germline mosaicism of KIF21A c.2860C>T is likely to cause the high occurrence of this mutation in the population. This information may be useful for genetic counseling. KIF21A mutations can affect the abducens nerve and cause complete absence of the bilateral superior rectus muscles. MRI characterization of new CFEOM1 phenotypes would assist clinical management.

Purpose To evaluate the precise association of complement factor H (CFH) Val62Ile polymorphism with age-related macular degeneration (AMD) susceptibility. Methods We performed a meta-analysis using databases including PubMed, EMBASE, and Web of Science to find relevant studies. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using fixed-effect and random-effects models. The inconsistency index (I2) was used to assess heterogeneity. Funnel plots and Egger’s test were used to evaluate publication bias. Sensitivity analysis was also performed. Results Fourteen studies including 4,438 patients with AMD and 6,099 controls based on the search criteria were involved in the meta-analysis. In overall populations, the pooled OR1 for genotype GA+GG versus homozygous genotype AA was 2.28 (95% confidence interval (CI): 1.48–3.52), the OR2 of heterozygous genotype GA versus AA was 1.58 (95% CI: 1.13–2.19), the OR3 of homozygous genotype GG versus AA was 2.90 (95% CI: 1.95–4.30), and the OR4 of allele G versus A was 1.77 (95% CI: 1.43–2.21). In Asian populations, our results provided substantial evidence that the Val62Ile variant was significantly associated with AMD (OR4=1.85, 95% CI: 1.63–2.09). However, in Caucasian populations, no significant association of Val62Ile with AMD was established in all circumstances. Conclusions Our analysis provides substantial evidence that the Val62Ile variant is significantly associated with AMD in Asian populations. However, our results have demonstrated no link between the Val62Ile polymorphism and AMD in Caucasian populations.