Understanding oxidative stress and HTRA1 locus in abnormal angiogenesis resulting in wet AMD pathology is an important step in developing a novel therapeutic approach.
A significant genotype and variant allele association was found of rs10490924 in ARMS2/HTRA1 with wet AMD, while the SNPs in CFH, CFB, and C3 were not associated with AMD in the current Pakistani cohort.
Variants in CFH and ARMS2/HTRA1, commonly associated with advanced AMD, were independently associated with an increase in drusen burden determined by OCT in an allele dose dependent manner, in eyes with early and intermediate AMD.
Transgenic zebrafish overexpressing human HTRA1 in rod PRCs showed morphologic changes of the RPE, including PRC death and lipofuscin accumulation, features similar to those of early AMD. htra1 expression was also increased in a retinitis pigmentosa zebrafish model compared with wild type.
The association of the SNP at the ARMS2/HTRA1 locus with subretinal/sub-RPE hemorrhage and poorer visual acuity and of SNPs at the CFH locus with drusen area may provide new insights in pathophysiological pathways underlying different stages of AMD.
A promoter variant of the gene encoding HTRA1 is part of a mutant allele that causes increased HTRA1 expression and contributed to age-related macular degeneration (AMD) in genomewide association studies.
Among the variants located at the 10q26 region, rs11200638, located at the HTRA1 gene promoter, has been associated with age-related macular degeneration in several populations and is considered the main polymorphism.
These cellular alterations correlate with the AMD phenotype and thus highlight HtrA1 as an intracellular target for therapeutic interventions towards AMD treatment.
HtrA1 is a serine protease suggested to play a role in the pathogenesis of various diseases, including age-related macular degeneration and osteoarthritis, by modulating extracellular matrix or cell surface proteins.
Our systematic search for interaction effects yielded significantly stronger effects among younger individuals at two known AMD loci (near CFH and ARMS2/HTRA1).
In this post hoc analysis of cross-sectional data from US participants in the Comparison of AMD Treatments Trials, genotyping was performed in 835 participants with TaqMan assays for the SNPs rs1061170 (Y402H variant in CFH), rs800292 (rs800292" genes_norm="3075">I62V variant in CFH), rs10490924 (rs10490924;s10490924" genes_norm="387715;717">A69S variant in ARMS2), rs11200638 (HTRA1), rs547154 (C2), rs2230199 (rs2230199" genes_norm="5654;718">R102G variant in C3), rs10468017 (LIPC), and rs4151667 (L9H variant in CFB).
In this study, we analyzed rare recombinant haplotypes in 16,144 AMD cases and 17,832 controls from the International AMD Genomics Consortium and identified variants in ARMS2 but not HTRA1 to exclusively carry the AMD risk with P-values between 1.0 × 10<sup>-773</sup> and 6.7 × 10<sup>-5</sup> This now allows prioritization of the gene of interest for subsequent functional studies.
We revealed a protective AMD-associated HTRA1 variant in Chinese populations and the biological role of HTRA1 in RPE cell degeneration, indicating its involvement in AMD pathogenesis.
High-temperature requirement A serine peptidase 1 (HTRA1) and age-related maculopathy susceptibility 2 (ARMS2) are two genes that are strongly associated with AMD.
Two loci in particular, including genes of the complement cascade on chromosome 1 and the ARMS2/HTRA1 genes on chromosome 10, have been shown to convey significantly increased susceptibility to developing AMD.
Our results revealed that HTRA1rs2672598 is more significantly associated with exudative AMD than PCV in ARMS2/HTRA1 region, and it is responsible for elevated HTRA1 transcriptional activity and HTRA1 protein expression.
It lies next to the ARMS2/HTRA1 genes in a region of chromosome 10q26, where single nucleotide variants have been strongly associated with age-related macular degeneration (AMD), the commonest cause of blindness in Western populations.
Six single nucleotide polymorphisms (SNPs) in this region and two known AMD-associated SNPs in CFH (rs800292) and HTRA1 (rs11200638) were genotyped in a Han Chinese cohort composed of 490 neovascular AMD patients, 419 PCV patients and 1316 controls.