To understand better the factors contributing to keratoconus (KTCN), we performed comprehensive transcriptome profiling of human KTCN corneas for the first time using an RNA-Seq approach. Twenty-five KTCN and 25 non-KTCN corneas were enrolled in this study. After RNA extraction, total RNA libraries were prepared and sequenced. The discovery RNA-Seq analysis (in eight KTCN and eight non-KTCN corneas) was conducted first, after which the replication RNA-Seq experiment was performed on a second set of samples (17 KTCN and 17 non-KTCN corneas). Over 82% of the genes and almost 75% of the transcripts detected as differentially expressed in KTCN and non-KTCN corneas were confirmed in the replication study using another set of samples. We used these differentially expressed genes to generate a network of KTCN-deregulated genes. We found an extensive disruption of collagen synthesis and maturation pathways, as well as downregulation of the core elements of the TGF-β, Hippo, and Wnt signaling pathways influencing corneal organization. This first comprehensive transcriptome profiling of human KTCN corneas points further to a complex etiology of KTCN.
Due to its localization and function, the cornea is regularly exposed to sunlight and atmospheric oxygen, mainly dioxygen, which produce reactive oxygen species (ROS). Therefore, corneal cells are particularly susceptible to oxidative stress. The accumulation of ROS in the cornea may affect signal transduction, proliferation and may also promote cell death. The cornea has several enzymatic and non-enzymatic antioxidants involved in ROS scavenging, but in certain conditions they may not cope with oxidative stress, leading to diseases of the eye. Keratoconus (KC) and Fuchs endothelial corneal dystrophy (FECD) are multifactorial diseases of the cornea, in which pathogenesis is not fully understood. However, increased levels of oxidative stress markers detected in these disorders indicate that oxidative stress may play an important role in their development and progression. These markers are: (i) decreased levels of non-enzymatic antioxidants, and (ii) decreased expression of genes encoding antioxidative enzymes, including thioredoxin reductase, peroxiredoxins, superoxide dismutase, glutathione S-transferase, and aldehyde dehydrogenase. Moreover, the FECD endothelium displays higher levels of oxidative DNA damage, especially in mitochondrial DNA (mtDNA), whereas KC cornea shows abnormal levels of some components of oxidative phosphorylation encoded by mtDNA. In this review we present some considerations and results of experiments supporting the thesis on the important role of oxidative stress in KC and FECD pathology.
Data on practice patterns for prophylaxis against infectious postoperative endophthalmitis (IPOE) during cataract surgery in 9 European countries were searched in national registers and reviews of published surveys. Summary reports assessed each nation's IPOE rates, nonantibiotic prophylactic routines, topical and intracameral antibiotic use, and coherence to the European Society of Cataract & Refractive Surgeons (ESCRS) 2007 guidelines. Although the reliability and completeness of available data vary between countries, the results show that IPOE rates differ significantly. Asepsis routines with povidone-iodine and postoperative topical antibiotics are generally adopted. Use of preoperative and perioperative topical antibiotics as well as intracameral cefuroxime varies widely between and within countries. Five years after publication of the ESCRS guidelines, there is no consensus on intracameral cefuroxime use. Major obstacles include legal barriers or persisting controversy about the scientific rationale for systematic intracameral cefuroxime use in some countries and, until recently, lack of a commercially available preparation.
Keratoconus (KTCN), a non-inflammatory corneal disorder characterized by stromal thinning, represents a major cause of corneal transplantations. Genetic and environmental factors have a role in the etiology of this complex disease. Previously reported linkage analysis revealed that chromosomal region 13q32 is likely to contain causative gene(s) for familial KTCN. Consequently, we have chosen eight positional candidate genes in this region: MBNL1, IPO5, FARP1, RNF113B, STK24, DOCK9, ZIC5 and ZIC2, and sequenced all of them in 51 individuals from Ecuadorian KTCN families and 105 matching controls. The mutation screening identified one mutation and three sequence variants showing 100% segregation under a dominant model with KTCN phenotype in one large Ecuadorian family. These substitutions were found in three different genes: c.2262A4C (p.Gln754His) and c.720+43A4G in DOCK9; c.2377-132A4C in IPO5 and c.1053+29G4C in STK24. PolyPhen analyses predicted that c.2262A4C (Gln754His) is possibly damaging for the protein function and structure. Our results suggest that c.2262A4C (p.Gln754His) mutation in DOCK9 may contribute to the KTCN phenotype in the large KTCN-014 family.
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Background: Primary open‐angle glaucoma (POAG) is the main cause of irreversible blindness worldwide. Matrix metalloproteinases (MMPs) and their regulators (TIMPs and ILs) have been extensively studied as POAG risk factors. Recent reports have showed several single‐nucleotide polymorphisms (SNPs) for MMPs, TIMPs and ILs encoding genes in patients with POAG. The aim of this study was to investigate association of the ‐1607 1G/2G MMP1, ‐the 1562 C/T MMP9, the ‐82 A/G MMP12, the ‐511 C/T IL‐1β and the 372 T/C TIMP1 gene polymorphisms with POAG occurrence and to investigate their impact on main clinical features.
Material and methods: In the present case–control study, we examined group of 511 unrelated Caucasian subjects consist of 255 patients with POAG (mean age 70 ± 15) and 256 controls (mean age 67 ± 16). Determination of genes polymorphic variants was made using polymerase chain reaction–restriction fragment length polymorphism technique (PCR‐RFLP). The odds ratios (ORs) and 95% confidence intervals (CIs) for each genotype and allele were calculated.
Results: Presented study showed statistically significant increase in the POAG development risk of the ‐1607 2G/2G MMP1 genotype (OR 1.75; 95% CI, 1.11–2.75; p = 0.014) and for the ‐1607 2G MMP1 allele (OR 1.35; 95% CI, 1.05–1.73; p = 0.017), as well as for the ‐1562 C/T MMP9 genotype (OR 1.74; 95% CI, 1.17–2.59; p = 0.006) and the ‐1562 T MMP9 allele (OR 1.55; 95% CI, 1.10–2.17; p = 0.012) in patients with POAG in comparison with healthy control group. We also observed positive association of the ‐511 T/T IL‐1β genotype (OR 2.60; 95% CI, 1.41–4.80; p = 0.002) as well as the ‐511 T IL‐1β allele occurrence with an increased POAG development risk (OR 1.47; 95% CI, 1.13–1.90; p = 0.003). Furthermore, we found an association of the ‐1607 1G/2G MMP1, ‐1562 C/T MMP9 (anova, p < 0.001) and the ‐511 C/T IL‐1β gene polymorphism (anova, p < 0.05) with decreased retinal nerve fibre layer (RNFL) thickness in patients with POAG group. Results displayed also an association of the 372 T/C TIMP1 gene polymorphism with normal range RNFL (anova, p < 0.001). We observed an association of decreased RA value (rim area) with the ‐82 A/G MMP12 (anova, p < 0.001). Normal RA value was observed in patients with POAG group connected with the 372 T/C TIMP1 (anova, p < 0.05) and the ‐511 C/T IL‐1β (anova, p < 0.05) genes polymorphisms occurrence. Finally, results showed an association of the ‐1562 C/T MMP9 (anova, p < 0.001) gene polymorphism with decreased cup/disc index in patients with POAG group.
Conclusion: In conclusion, we suggest that the ‐1607 1G/2G MMP1, ‐1562 C/T MMP9, ‐511 C/T IL‐1β gene polymorphisms can be considered as an important risk factors associated with POAG.
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