Pharmacogenetic Association between Allelic Variants of the Autophagy-Related Genes and Anti-Vascular Endothelial Growth Factor Treatment Response in Neovascular Age-Related Macular Degeneration.

BACKGROUND: Age-related macular degeneration (AMD) is the leading cause of late-onset blindness in elderly. The occurrence and development of AMD is a multifactorial complex process where autophagy plays an important role. The first-line drugs for neovascular AMD (nAMD) are inhibitors of VEGF, with up to 30% of patients having an incomplete response to treatment. Genetic factors may influence the response to anti-VEGF therapy and explain treatment outcome variability. We aimed to estimate the role of polymorphic markers of the MTOR (rs1064261, rs1057079, rs11121704, rs2295080), SQSTM1 (rs10277), ULK1 (rs11246867, rs3088051), MAP1LC3A (rs73105013) and ATG5 (rs573775) genes in the development of nAMD and the efficacy of anti-VEGF therapy response. METHODS: Genotyping by allele-specific PCR was performed in 317 controls and 315 nAMD patients in the Russian population. Of them, 196 treatment-naive nAMD patients underwent three monthly intravitreal injections (IVIs) of aflibercept. Genotypic frequencies were compared with OCT markers of therapy effectiveness and best-corrected visual acuity (BCVA) measures. The main outcomes were the BCVA gain and decrease in central retinal thickness (CRT). RESULTS: MTOR-rs1057079-C, MTOR-rs11121704-C and MTOR-rs2295080-G alleles were associated with an increased risk of nAMD. The BCVA was increased in 117 (59.7%) patients by 10 [5-20] letters, did not changed in 59 (30.1%), and was decreased in 20 (10.2%) patients. ULK1-rs3088051 was associated with BCVA change. Among patients with the TT and CT genotypes for ULK1-rs3088051, an improvement in visual acuity was noted in 67.6% and 53.8% of cases, while in patients with the CC genotype, an increase in BCVA was recorded in 37.5% of cases (p = 0.01). The decrease in CRT was associated with SQSTM1-rs10277 (p = 0.001): it was significantly higher in TT (93 [58-122] mkm) and CT (66 [30-105] mkm) carriers compared to the CC genotype (47 [24-68] mkm). Other SNPs did not show significant associations with the outcome of anti-VEGF treatment. CONCLUSIONS: MTOR gene polymorphisms are moderately associated with the risk of nAMD. SQSTM1-rs10277 and ULK1-rs3088051 may influence short-term response to intravitreal anti-VEGF treatment. The results suggest that autophagy could be a target for future drugs to overcome resistance to anti-VEGF therapy.

Association between Polymorphisms in CFH, ARMS2, CFI, and C3 Genes and Response to Anti-VEGF Treatment in Neovascular Age-Related Macular Degeneration.

Neovascular age-related macular degeneration (nAMD) is the leading cause of vision loss in the elderly. The gold standard of nAMD treatment is intravitreal injections of vascular endothelial growth factor (VEGF) inhibitors. Genetic factors may influence the response to anti-VEGF therapy and result in a high degree of response variability. The aim of the study was to evaluate the association of the polymorphisms in genes related to the complement system (rs2285714-CFI, rs10490924-ARMS2, rs2230199-C3, rs800292-CFH, and rs6677604-CFH) with nAMD its clinical features and optical coherent tomography (OCT) biomarkers of treatment response to anti-VEGF therapy. Genotyping by allele-specific PCR was performed in 193 AMD patients and 147 age-matched controls. A prospective study of the dynamics of changes in OCT biomarkers during aflibercept treatment included 110 treatment-naive patients. Allele T rs10490924 was associated with the increased risk of nAMD. For both rs800292 and rs6677604, carriage of the A allele was protective and decreased the nAMD risk. Associations of rs2230199 with central retinal thickness (CRT) and intraretinal cysts were revealed. The height of pigment epithelium detachment and the height of neuroretinal detachment were significantly higher in carriers of the minor allele of rs2285714, both at baseline and during treatment. The reduction of CRT was associated with higher CRT at baseline and the presence of the T allele of rs2285714. By the end of one-year follow-up the patients homozygous for the minor allele rs2285714 had significantly higher odds of the presence of anastomoses and loops and active neovascular membrane. Furthermore, minor allele carriers had decreased levels of complement factor I level in aqueous humor but not in the plasma, which may be due to the influence of rs2285714 on tissue-specific splicing. Our results suggest that the severity of AMD macular lesions is associated with rs2285714 and rs2230199 polymorphisms, which could be explained by their high regulatory potential. Patients with the minor allele of rs2285714 respond worse to antiangiogenic therapy.

Single-Nucleotide Polymorphisms (SNPs) Both Associated with Hypertension and Contributing to Accelerated-Senescence Traits in OXYS Rats.

Aging is a major risk factor of numerous human diseases. Adverse genetic variants may contribute to multiple manifestations of aging and increase the number of comorbid conditions. There is evidence of links between hypertension and age-related diseases, although the genetic relationships are insufficiently studied. Here, we investigated the contribution of hypertension to the development of accelerated-senescence syndrome in OXYS rats. We compared transcriptome sequences of the prefrontal cortex, hippocampus, and retina of OXYS rats with the genotypes of 45 rat strains and substrains (which include models with hypertension) to find single-nucleotide polymorphisms (SNPs) both associated with hypertension and possibly contributing to the development of age-related diseases. A total of 725 polymorphisms were common between OXYS rats and one or more hypertensive rat strains/substrains being analyzed. Multidimensional scaling detected significant similarities between OXYS and ISIAH rat genotypes and significant differences between these strains and the other hypertensive rat strains/substrains. Nonetheless, similar sets of SNPs produce a different phenotype in OXYS and ISIAH rats depending on hypertension severity. We identified 13 SNPs causing nonsynonymous amino-acid substitutions having a deleterious effect on the structure or function of the corresponding proteins and four SNPs leading to functionally significant structural rearrangements of transcripts in OXYS rats. Among them, SNPs in genes Ephx1, Pla2r1, and Ccdc28b were identified as candidates responsible for the concomitant manifestation of hypertension and signs of accelerated aging in OXYS rats.

Single-Nucleotide Polymorphisms Associated with the Senescence-Accelerated Phenotype of OXYS Rats: A Focus on Alzheimer's Disease-Like and Age-Related-Macular-Degeneration-Like Pathologies.

Alzheimer's disease (AD) and age-related macular degeneration (AMD) are two complex incurable neurodegenerative disorders the common pathogenesis of which is actively discussed. There are overlapping risk factors and molecular mechanisms of the two diseases; at the same time, there are arguments in favor of the notion that susceptibility to each of these diseases is associated with a distinct genetic background. Here we identified single-nucleotide polymorphisms (SNPs) that are specific for senescence-accelerated OXYS rats, which simulate key characteristics of both sporadic AD and AMD. Transcriptomes of the hippocampus, prefrontal cortex, and retina (data of RNA-Seq) were analyzed. We detected SNPs in genes Rims2, AABR07072639.2, Lemd2, and AABR07045405.1, which thus can express significantly truncated proteins lacking functionally important domains. Additionally, 33 mutations in genes-which are related to various metabolic and signaling pathways-cause nonsynonymous amino acid substitutions presumably leading to disturbances in protein structure or functions. Some of the genes carrying these SNPs are associated with aging, neurodegenerative, and mental diseases. Thus, we revealed the SNPs can lead to abnormalities in protein structure or functions and affect the development of the senescence-accelerated phenotype of OXYS rats. Our data are consistent with the latest results of genome-wide association studies that highlight the importance of multiple pathways for the pathogenesis of AD and AMD. Identified SNPs can serve as promising research objects for further studies on the molecular mechanisms underlying this particular rat model as well as for the prediction of potential biomarkers of AD and AMD.

Involvement of the autophagic pathway in the progression of AMD-like retinopathy in senescence-accelerated OXYS rats.

Age-related macular degeneration (AMD) is a complex neurodegenerative disease resulting in a loss of central vision in the elderly. It is currently assumed that impairment of autophagy may be one of the key mechanisms leading to AMD. Here we estimated the influence of age-related autophagy alterations in the retina on the development of AMD-like retinopathy in senescence-accelerated OXYS rats. Significant changes in the expression of the autophagy proteins were absent at the age preceding the development of retinopathy (age 20 days). We found increased levels of LC3A/B, Atg7, and Atg12-Atg5 conjugated proteins in the OXYS retina during manifestation of this retinopathy at the age of 3 months. By contrast, in the retina of 18-month-old OXYS rats with a progressive stage of retinopathy, we revealed significantly decreased protein levels of Atg7 and Atg12-Atg5 as compared to age-matched Wistar rats. Simultaneously with perturbation of the autophagic response, the necrosome subunits Ripk1 and Ripk3 were detected in the OXYS retina. The downregulation of autophagy markers coincided with amyloid ß accumulation (Moab-2) in the retinal pigment epithelium and choroid. Using high-throughput RNA sequencing, we found a missense single-nucleotide polymorphism (SNP) in the Pik3c2b gene associated with autophagy regulation. This SNP was predicted to significantly affect protein structure. Our data prove participation of the autophagic pathway in the progression of AMD-like retinopathy.

Phosphorylation of αB-crystallin in the myocardium: Analysis of relations with aging and cardiomyopathy.

Phosphorylation is a major post-translational modification of αB-crystallin (CryaB) and determines this protein's chaperone activity, intracellular distribution, translocation, and cytoprotective functions. Phosphorylation of CryaB manifests itself as either beneficial or deleterious consequences depending on the extent of phosphorylation and interaction with the cytoskeleton. Herein, for the first time, we compared the age-related alterations of the expression and phosphorylation (on Ser59: pS59) of CryaB in the myocardium of Wistar and senescence-accelerated OXYS rats. The latters, as we demonstrated here, develop cardiomyopathy by the age of 12 months against the background of hypertension. Rats at the age of 20 days, 3, 12, and 24 months were used. The expression of CryaB mRNA (studied by RT-PCR) and of the CryaB protein (analyzed by western blotting) increased with age in the myocardium of both Wistar and OXYS rats, but only at the age of 24 months did their levels become lower in OXYS rats. Phosphorylation of CryaB increased with age in all rats. There was no association of cardiomyopathy with the pS59-CryaB amount in the detergent-soluble fraction either. Moreover, immunostaining of the myocardium revealed that the amount of pS59-CryaB was greater in OXYS rats than in the control animals. This phenomenon was the result of translocation of pS59-CryaB from the detergent-soluble protein fraction to the detergent-insoluble one. The amount of pS59-CryaB in striated sarcomeres (detergent-insoluble) of the myocardium increased with age in both strains but faster in the myocardium of OXYS rats, and its accumulation preceded the development of cardiomyopathy. Translocation of phosphorylated CryaB to sarcomeres affects functional and structural properties (of cardiomyocytes) that are crucial for contractile function and myofibrillar organization and may be an important component of an endogenous mechanism of aging of the myocardium.