A Study on the Candidate Gene Association and Interaction with Measures of UV Exposure in Pseudoexfoliation Patients from India

PURPOSE

Environmental and genetic factors are associated with development of Pseudoexfoliation syndrome (XFS). Here we intended to elucidate the association of candidate genes in relevance to UV exposure in these patients.

METHODS

This is a case-control study of 309 subjects (N = 219 controls and 90 XFS cases) from India. PCR based direct sequencing was performed for candidate genes (LOXL1, POMP and TMEM136) followed by genotype and haplotype analysis. The promoter methylation status was assessed by Methylation specific PCR based direct sequencing of genomic DNA for all samples. The methylation status was compared with that of primary fibroblasts cultures established from patient's Tenon's tissue samples in subset of these patients.

RESULTS

SNPs rs3825942, rs41435250, rs8818 (LOXL1) and rs3737528 (POMP) showed significant association with XFS. LOXL1 gene haplotype GAGC (rs1048661- rs3825942- rs41435250-rs8818) was associated with lower risk for XFS with a p value 4.1961 × 10-6 (OR =0; 95%CI, 0.000-0.003). POMP gene haplotypes for intronic SNPs (rs1340815- rs3737528- rs913797) TCC and TTC were associated with increased risk for the disease (OR > 1.0). Significant correlation for SNPs rs3825942 of LOXL1 (ρ= -0.132) and rs3737528 of POMP (ρ = 0.12) was observed with measure of lifetime UV exposure (CUVAF value). Reduced LOXL1 gene expression was observed in cultured tenon fibroblasts from the patients that correlated with differential methylation of the Sp-1 binding sites at -253, -243bp upstream to the transcription start site of LOXL1 promoter region.

CONCLUSION

Our results suggest a possible interaction for LOXL1 gene haplotype (GAGC) with the measure of ocular UV exposure in pseudoexfoliation syndrome.

Molecular Processes in Stress Urinary Incontinence: A Systematic Review of Human and Animal Studies

Stress urinary incontinence (SUI) is a common and burdensome condition. Because of the large knowledge gap around the molecular processes involved in its pathophysiology, the aim of this review was to provide a systematic overview of genetic variants, gene and protein expression changes related to SUI in human and animal studies. On 5 January 2021, a systematic search was performed in Pubmed, Embase, Web of Science, and the Cochrane library. The screening process and quality assessment were performed in duplicate, using predefined inclusion criteria and different quality assessment tools for human and animal studies respectively. The extracted data were grouped in themes per outcome measure, according to their functions in cellular processes, and synthesized in a narrative review. Finally, 107 studies were included, of which 35 used animal models (rats and mice). Resulting from the most examined processes, the evidence suggests that SUI is associated with altered extracellular matrix metabolism, estrogen receptors, oxidative stress, apoptosis, inflammation, neurodegenerative processes, and muscle cell differentiation and contractility. Due to heterogeneity in the studies (e.g., in examined tissues), the precise contribution of the associated genes and proteins in relation to SUI pathophysiology remained unclear. Future research should focus on possible contributors to these alterations.