Systemic and ocular fluid compounds as potential biomarkers in age-related macular degeneration

Biomarkers can help unravel mechanisms of disease and identify new targets for therapy. They can also be useful in clinical practice for monitoring disease progression, evaluation of treatment efficacy, and risk assessment in multifactorial diseases, such as age-related macular degeneration (AMD). AMD is a highly prevalent progressive retinal disorder for which multiple genetic and environmental risk factors have been described, but the exact etiology is not yet fully understood. Many compounds have been evaluated for their association with AMD. We performed an extensive literature review of all compounds measured in serum, plasma, vitreous, aqueous humor, and urine of AMD patients. Over 3600 articles were screened, resulting in more than 100 different compounds analyzed in AMD studies, involved in neovascularization, immunity, lipid metabolism, extracellular matrix, oxidative stress, diet, hormones, and comorbidities (such as kidney disease). For each compound, we provide a short description of its function and discuss the results of the studies in relation to its usefulness as AMD biomarker. In addition, biomarkers identified by hypothesis-free techniques, including metabolomics, proteomics, and epigenomics, are covered. In summary, compounds belonging to the oxidative stress pathway, the complement system, and lipid metabolism are the most promising biomarker candidates for AMD. We hope that this comprehensive survey of the literature on systemic and ocular fluid compounds as potential biomarkers in AMD will provide a stepping stone for future research and possible implementation in clinical practice

Systemic and ocular fluid compounds as potential biomarkers in age-related macular degeneration

Biomarkers can help unravel mechanisms of disease and identify new targets for therapy. They can also be useful in clinical practice for monitoring disease progression, evaluation of treatment efficacy, and risk assessment in multifactorial diseases, such as age-related macular degeneration (AMD). AMD is a highly prevalent progressive retinal disorder for which multiple genetic and environmental risk factors have been described, but the exact etiology is not yet fully understood. Many compounds have been evaluated for their association with AMD. We performed an extensive literature review of all compounds measured in serum, plasma, vitreous, aqueous humor, and urine of AMD patients. Over 3600 articles were screened, resulting in more than 100 different compounds analyzed in AMD studies, involved in neovascularization, immunity, lipid metabolism, extracellular matrix, oxidative stress, diet, hormones, and comorbidities (such as kidney disease). For each compound, we provide a short description of its function and discuss the results of the studies in relation to its usefulness as AMD biomarker. In addition, biomarkers identified by hypothesis-free techniques, including metabolomics, proteomics, and epigenomics, are covered. In summary, compounds belonging to the oxidative stress pathway, the complement system, and lipid metabolism are the most promising biomarker candidates for AMD. We hope that this comprehensive survey of the literature on systemic and ocular fluid compounds as potential biomarkers in AMD will provide a stepping stone for future research and possible implementation in clinical practice

GENETIC RISK FACTORS IN ACUTE CENTRAL SEROUS CHORIORETINOPATHY

PURPOSE: To investigate genetic associations in white patients with acute central serous chorioretinopathy (aCSC) and to assess genetic differences between aCSC and chronic CSC (cCSC). METHODS: A total of 135 aCSC patients, 272 cCSC patients, and 1,385 control individuals were included. Eight single nucleotide polymorphisms were genotyped for ARMS2 (rs10490924), CFH (rs800292, rs1061170, rs1065489, rs1329428, rs2284664, rs3753394), and NR3C2 (rs2070951). Also, C4B gene copy numbers were analyzed. RESULTS: Three single nucleotide polymorphisms in the CFH gene were significantly associated with aCSC: rs800292 (P = 0.003, odds ratio = 1.53 [95% confidence interval = 1.15-2.03]), rs1061170 (P = 0.002, odds ratio = 0.64 [95% confidence interval = 0.48-0.86]), and rs1329428 (P = 5.87 × 10, odds ratio = 1.83 [95% confidence interval = 1.40-2.38]). A significant difference was found in the distribution of C4B gene copy numbers in aCSC patients compared with controls (P = 0.0042). No differences could be found among the selected variants between aCSC and cCSC patients. CONCLUSION: Three variants in the CFH gene and copy number variations in C4B were found to be significantly associated with the risk of aCSC development. Despite the differences in clinical presentation, acute and chronic CSC may share a similar genetic predisposition based on our present analysis. Other genetic and/or nongenetic risk factors may be more influential in the differentiation toward an acute or a chronic phenotype of CSC

GENETIC RISK FACTORS IN ACUTE CENTRAL SEROUS CHORIORETINOPATHY

Purpose: To investigate genetic associations in white patients with acute central serous chorioretinopathy (aCSC) and to assess genetic differences between aCSC and chronic CSC (cCSC). Methods: A total of 135 aCSC patients, 272 cCSC patients, and 1,385 control individuals were included. Eight single nucleotide polymorphisms were genotyped for ARMS2 (rs10490924), CFH (rs800292, rs1061170, rs1065489, rs1329428, rs2284664, rs3753394), and NR3C2 (rs2070951). Also, C4B gene copy numbers were analyzed. Results: Three single nucleotide polymorphisms in the CFH gene were significantly associated with aCSC: rs800292 (P = 0.003, odds ratio = 1.53 [95% confidence interval = 1.15-2.03]), rs1061170 (P = 0.002, odds ratio = 0.64 [95% confidence interval = 0.48-0.86]), and rs1329428 (P = 5.87 x 10(-6), odds ratio = 1.83 [95% confidence interval = 1.40-2.38]). A significant difference was found in the distribution of C4B gene copy numbers in aCSC patients compared with controls (P = 0.0042). No differences could be found among the selected variants between aCSC and cCSC patients. Conclusion: Three variants in the CFH gene and copy number variations in C4B were found to be significantly associated with the risk of aCSC development. Despite the differences in clinical presentation, acute and chronic CSC may share a similar genetic predisposition based on our present analysis. Other genetic and/or nongenetic risk factors may be more influential in the differentiation toward an acute or a chronic phenotype of CSC

GENETIC RISK FACTORS IN SEVERE, NONSEVERE AND ACUTE PHENOTYPES OF CENTRAL SEROUS CHORIORETINOPATHY

Purpose: To study genetic predispositions and differences between severe chronic central serous chorioretinopathy (cCSC), nonsevere cCSC, and acute central serous chorioretinopathy (aCSC). Methods: One hundred seventy-three severe cCSC patients, 272 nonsevere cCSC patients, 135 aCSC patients, and 1,385 control individuals were included. Eight single-nucleotide polymorphisms were genotyped in theARMS2(rs10490924),CFH(rs800292, rs1061170, rs1065489, rs1329428, rs2284664, rs3753394), andNR3C2(rs2070951). Additionally,C4Bgene copy numbers were analyzed. Results: A significant association in 5 single-nucleotide polymorphisms in theCFHgene could be reproduced among severe cCSC patients, including rs800292 (P= 0.0014; odds ratio [OR] = 1.93; 95% confidence interval [CI] = 1.51-2.47), rs1065489 (P= 2.22 x 10(-4); OR = 0.49; 95% CI = 0.34-0.72), rs1329428 (P= 0.001; OR = 1.89; 95% CI = 1.49-2.40), rs2284664 (P= 1.21x 10(-4); OR = 1.65; 95% CI = 1.28-2.13), and rs3753394 (P= 6.10x 10(-4); OR = 0.61; 95% CI = 0.46-0.81). Carrying threeC4Bcopies was protective for severe cCSC (P= 0.001; OR = 0.29; 95% CI = 0.14-0.61). No significant differences in allele frequencies could be found among the CSC phenotypes. Conclusion: Acute CSC, nonsevere cCSC, and severe cCSC all showed a similar association with theCFHandC4Bgenes, and the three phenotypes could not be distinguished based on the genetics. This shows that despite the differences in clinical presentation and severity, there is an overlap in the genetic predisposition of different CSC phenotypes. Nongenetic factors may play a more important role in determining the clinical course of CSC

FAMILIAL CENTRAL SEROUS CHORIORETINOPATHY

PURPOSE: To assess ophthalmologic characteristics in patients and unaffected individuals in families with multiple members affected by central serous chorioretinopathy (CSC), both at presentation and long-term follow-up. METHODS: In 103 subjects from 23 families with at least 2 affected patients with CSC per family, prospective extensive ophthalmologic examination was performed, including best-corrected visual acuity, indirect ophthalmoscopy, digital color fundus photography, optical coherence tomography, fundus autofluorescence, and fluorescein angiography imaging. From these, 24 individuals from 6 families had undergone extensive ophthalmologic examination in either 1994 or 1995 and were followed up in this study. RESULTS: Subretinal fluid accumulation on optical coherence tomography and/or "hot spots" of leakage on fluorescein angiography indicative of CSC were detected in 45 of 103 phenotyped subjects (44%). Findings suggestive of CSC, but without the presence of subretinal fluid on optical coherence tomography and/or "hot spots" of leakage on fluorescein angiography, were observed in an additional 27 family members (26%). In 4 of 17 previously nonaffected subjects (24%) from the 24 individuals that were followed up after more than 20 years, we found more severe abnormalities. CONCLUSION: Extensive ophthalmologic phenotyping resulted in the detection of (suggestive) CSC in 52% of family members of patients with CSC. Genetic factors may play an important role in these specific CSC cases. Moreover, during follow-up, progressive disease can occur in a noteworthy number of patients

Genome-wide association analyses identify two susceptibility loci for pachychoroid disease central serous chorioretinopathy

特殊な網膜剥離の発症に関わる遺伝子変異を発見 --中心性漿液性脈絡網膜症のゲノムワイド関連解析--. 京都大学プレスリリース. 2019-12-13.The recently emerged pachychoroid concept has changed the understanding of age-related macular degeneration (AMD), which is a major cause of blindness; recent studies attributed AMD in part to pachychoroid disease central serous chorioretinopathy (CSC), suggesting the importance of elucidating the CSC pathogenesis. Our large genome-wide association study followed by validation studies in three independent Japanese and European cohorts, consisting of 1546 CSC samples and 13, 029 controls, identified two novel CSC susceptibility loci: TNFRSF10A-LOC389641 and near GATA5 (rs13278062, odds ratio = 1.35, P = 1.26 × 10−13; rs6061548, odds ratio = 1.63, P = 5.36 × 10−15). A T allele at TNFRSF10A-LOC389641 rs13278062, a risk allele for CSC, is known to be a risk allele for AMD. This study not only identified new susceptibility genes for CSC, but also improves the understanding of the pathogenesis of AMD

Association of a Haplotype in the NR3C2 Gene, Encoding the Mineralocorticoid Receptor, With Chronic Central Serous Chorioretinopathy

IMPORTANCE Chronic central serous chorioretinopathy (cCSC) is a chorioretinal disease with unknown disease etiology. The glucocorticoid receptor and the mineralocorticoid receptor, 2 glucocorticoid-binding receptors, might be involved in the pathogenesis of cCSC. OBJECTIVE To assess the association of functional variants and haplotypes in the glucocorticoid receptor (NR3C1) and mineralocorticoid receptor (NR3C2) genes with cCSC. DESIGN, SETTING, AND PARTICIPANTS In this case-control genetic association study, 336 patients with cCSC and 1314 unaffected controls, collected at 3 university medical centers from September 1, 2009, to May 1, 2016, underwent KASP genotyping for selected variants in NR3C1 (rs56149945, rs41423247, and rs6198) and NR3C2 (rs2070951 and rs5522). MAIN OUTCOMES AND MEASURES Genetic associations of 3 NR3C1 variants and 2 NR3C2 variants with cCSC. RESULTS Among the 336 patients (274 men and 62 women; mean [ SD] age, 52 [10] years), after correction for multiple testing, rs2070951 in the NR3C2 gene was significantly associated with cCSC (odds ratio, 1.29; 95% CI, 1.08-1.53; P = .004). Moreover, the GA haplotype of single-nucleotide polymorphisms rs2070951 and rs5522 in NR3C2 conferred risk for cCSC (odds ratio, 1.39; 95% CI, 1.15-1.68; P = .004), whereas the CA haplotype decreased risk for cCSC (odds ratio, 0.72; 95% CI, 0.60-0.87; P < .001). Three known variants in NR3C1 that alter the activity of the glucocorticoid receptor (rs56149945, rs41423247, and rs6198) were not associated with cCSC. CONCLUSIONS AND RELEVANCE In this study, the variant rs2070951 and the GA haplotype in NR3C2 were associated with an increased risk for cCSC. Results of this genetic study support a possible role for the mineralocorticoid receptor in the pathogenesis of cCSC. Since these haplotypes have previously been associated with perceived stress, this study provides a clue to bridging clinical risk factors for cCSC to underlying genetic associations

Conserved regulation of neurodevelopmental processes and behavior by FoxP in Drosophila

International audienceFOXP proteins form a subfamily of evolutionarily conserved transcription factors involved in the development and functioning of several tissues, including the central nervous system. In humans, mutations in FOXP1 and FOXP2 have been implicated in cognitive deficits including intellectual disability and speech disorders. Drosophila exhibits a single ortholog, called FoxP, but due to a lack of characterized mutants, our understanding of the gene remains poor. Here we show that the dimerization property required for mammalian FOXP function is conserved in Drosophila. In flies, FoxP is enriched in the adult brain, showing strong expression in ~1000 neurons of cholinergic, glutamatergic and GABAergic nature. We generate Drosophila loss-of-function mutants and UAS-FoxP transgenic lines for ectopic expression, and use them to characterize FoxP function in the nervous system. At the cellular level, we demonstrate that Drosophila FoxP is required in larvae for synaptic morphogenesis at axonal terminals of the neuromuscular junction and for dendrite development of dorsal multidendritic sensory neurons. In the developing brain, we find that FoxP plays important roles in α-lobe mushroom body formation. Finally, at a behavioral level, we show that Drosophila FoxP is important for locomotion, habituation learning and social space behavior of adult flies. Our work shows that Drosophila FoxP is important for regulating several neurodevelopmental processes and behaviors that are related to human disease or vertebrate disease model phenotypes. This suggests a high degree of functional conservation with vertebrate FOXP orthologues and established flies as a model system for understanding FOXP related pathologies

Role of the Complement System in Chronic Central Serous Chorioretinopathy: A Genome-Wide Association Study

Importance: To date, several targeted genetic studies on chronic central serous chorioretinopathy (cCSC) have been performed; however, unbiased genome-wide studies into the genetics of cCSC have not been reported. To discover new genetic loci associated with cCSC and to better understand the causative mechanism of this disease, we performed a genome-wide association study (GWAS) on patients with cCSC. Objective: To discover new genetic loci and pathways associated with cCSC and to predict the association of genetic variants with gene expression in patients with cCSC. Design, Setting, and Participants: This case-control GWAS was completed in the general community, 3 referral university medical centers, and outpatient care on Europeans individuals with cCSC and population-based control participants. Genotype data was collected from May 2013 to August 2017, and data analysis occurred from August 2017 to November 2017. Main Outcomes and Measures: Associations of single-nucleotide polymorphisms, haplotypes, genetic pathways, and predicted gene expression with cCSC. Results: A total of 521 patients with cCSC (median age, 51 years; interquartile range [IQR], 44-59 years; 420 [80.6%] male) and 3577 European population-based control participants (median age, 52 years; IQR, 37-71 years; 1630 [45.6%] male) were included. One locus on chromosome 1 at the complement factor H (CFH) gene reached genome-wide significance and was associated with an increased risk of cCSC (rs1329428; odds ratio [OR], 1.57 [95% CI, 1.38-1.80]; P = 3.12 × 10-11). The CFH haplotypes H1 and H3 were protective for cCSC (H1: OR, 0.64 [95% CI, 0.53-0.77]; P = 2.18 × 10-6; H3: OR, 0.54 [95% CI, 0.42-0.70]; P = 2.49 × 10-6), whereas haplotypes H2, H4, H5, and the aggregate of rare CFH haplotypes conferred increased risk (H2: OR, 1.57 [95% CI, 1.30-1.89]; P = 2.18 × 10-6; H4: OR, 1.43 [95% CI, 1.13-1.80]; P = 2.49 × 10-3; H5: OR, 1.80 [95% CI, 1.36-2.39]; P = 4.61 × 10-5; rare haplotypes: OR, 1.99 [95% CI, 1.43-2.77]; P = 4.59 × 10-5). Pathway analyses showed involvement of the complement cascade and alternative open reading frame (ARF) pathway in cCSC. Using PrediXcan, we identified changes in predicted expression of complement genes CFH, complement factor H related 1 (CFHR1), complement factor related 4 (CFHR4), and membrane cofactor protein (MCP/CD46). Additionally, the potassium sodium-activated channel subfamily T member 2 (KCNT2) and tumor necrosis factor receptor superfamily member 10a (TNFRSF10A) genes were differentially expressed in patients with cCSC. Conclusions and Relevance: In this GWAS on cCSC, we identified a locus on chromosome 1 at the CFH gene that was significantly associated with cCSC, and we report protective and risk-conferring haplotypes in this gene. Pathway analyses were enriched for complement genes, and gene expression analysis suggests a role for CFH, CFHR1, CFHR4, CD46, KCNT2, and TNFRSF10A in the disease. Taken together, these results underscore the potential importance of the complement pathway in the causative mechanisms of cCSC