Haines JL, Hauser MA, Schmidt S, Scott WK, Olson LM, Gallins P et al. Complement factor H variant increases the risk of age-related macular degeneration. Science 2005; 308: 419-421
ABSTRACT Age-related macular degeneration (AMD) is a leading cause of visual impairment and blindness in the elderly whose etiology remains largely unknown. Previous studies identified chromosome 1q32 as harboring a susceptibility locus for AMD. We used single-nucleotide polymorphisms to interrogate this region and identified a strongly associated haplotype in two independent data sets. DNA resequencing of the complement factor H gene within this haplotype revealed a common coding variant, Y402H, that significantly increases the risk for AMD with odds ratios between 2.45 and 5.57. This common variant likely explains approximately 43% of AMD in older adults.
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Article: Haines JL, Hauser MA, Schmidt S, Scott WK, Olson LM, Gallins P et al. Complement factor H variant increases the risk of age-related macular degeneration. Science 2005; 308: 419-421
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- "CFH CFH is the primary inhibitor of the alternative complement pathway. Genetic studies identified strong associations between AMD and a coding variant (Tyr402His; rs1061170) and several noncoding variants in the CFH gene (Edwards et al. 2005; Hageman et al. 2005; Haines et al. 2005). In addition to these common genetic variants , rare variants with an even larger effect have been identified in the CFH gene (Fig. 2A). "
ABSTRACT: Age-related macular degeneration (AMD) is a complex disease caused by a combination of genetic and environmental factors. Genome-wide association studies have identified several common genetic variants associated with AMD, which together account for 15%-65% of the heritability of AMD. Multiple hypotheses to clarify the unexplained portion of genetic variance have been proposed, such as gene-gene interactions, gene-environment interactions, structural variations, epigenetics, and rare variants. Several studies support a role for rare variants with large effect sizes in the pathogenesis of AMD. In this work, we review the methods that can be used to detect rare variants in common diseases, as well as the recent progress that has been made in the identification of rare variants in AMD. In addition, the relevance of these rare variants for diagnosis, prognosis, and treatment of AMD is highlighted.Cold Spring Harbor Perspectives in Medicine 11/2014; 5(3). DOI:10.1101/cshperspect.a017202 · 7.56 Impact Factor
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- "Homeostatic disturbances, when uncompensated, lead to sustained oxidative stress and compromised mitochondrial function, resulting in apoptotic cell death (Bazan 2007; de Jong 2006; Dunaief et al. 2002; Feher et al. 2006; Lukiw et al. 2005; Mendes et al. 2005; Sreekumar et al. 2005; Takahashi et al. 2004). Single nucleotide polymorphisms (SNPs) occurring in complement factor H gene (CFH/HF1) (Edwards et al. 2005; Hageman et al. 2005; Haines et al. 2005; Klein et al. 2005) are a major risk factor for developing AMD. CFH is an inhibitor of the alternative pathway of complement system activation that limits complement-induced cell injury and inflammation (Bok 2005; Gold et al. 2006). "
ABSTRACT: Docosahexaenoic acid (DHA), an omega-3 fatty acid family member, is obtained by diet or synthesized from dietary essential omega-3 linolenic acid and delivered systemically to the choriocapillaris, from where it is taken up by the retinal pigment epithelium (RPE). DHA is then transported to the inner segments of photoreceptors, where it is incorporated in phospholipids during the biogenesis of outer segment disk and plasma membranes. As apical photoreceptor disks are gradually shed and phagocytized by the RPE, DHA is retrieved and recycled back to photoreceptor inner segments for reassembly into new disks. Under uncompensated oxidative stress, the docosanoid neuroprotectin D1 (NPD1), a potent mediator derived from DHA, is formed by the RPE and displays its bioactivity in an autocrine and paracrine fashion. The purpose of this study was to determine whether photoreceptors have the ability to synthesize NPD1, and whether or not this lipid mediator exerts bioactivity on these cells. For this purpose, 661W cells (mouse-derived photoreceptor cells) were used. First we asked whether these cells have the ability to form NPD1 by incubating cells with deuterium (d4)-labeled DHA exposed to dark and bright light treatments, followed by LC-MS/MS-based lipidomic analysis to identify and quantify d4-NPD1. The second question pertains to the potential bioactivity of these lipids. Therefore, cells were incubated with 9-cis-retinal in the presence of bright light that triggers cell damage and death. Following 9-cis-retinal loading, DHA, NPD1, or vehicle were added to the media and the 661W cells maintained either in darkness or under bright light. DHA and NPD1 were then quantified in cells and media. Regardless of lighting conditions, 661W cells acquired DHA from the media and synthesized 4-9 times as much d4-NPD1 under bright light treatment in the absence and presence of 9-cis-retinal compared to cells in darkness. Viability assays of 9-cis-retinal-treated cells demonstrated that 34 % of the cells survived without DHA or NPD1. However, after bright light exposure, DHA protected 23 % above control levels and NPD1 increased protection by 32 %. In conclusion, the photoreceptor cell line 661W has the capability to synthesize NPD1 from DHA when under stress, and, in turn, can be protected from stress-induced apoptosis by DHA or NPD1, indicating that photoreceptors effectively contribute to endogenous protective signaling mediated by NPD1 under stressful conditions.Cellular and Molecular Neurobiology 09/2014; 35(2). DOI:10.1007/s10571-014-0111-4 · 2.20 Impact Factor
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- "Thus, the expression of certain genes may reveal both protective and detrimental characteristics, depending on the phase of the disease (see Table 1). Following the discovery that retinal drusen contain CSrelated proteins, several reports appeared in 2005 and stated that the chromosomal region 1q31 that encodes CFH is a major susceptibility locus for AMD according to wholegenome association analyses performed independently in three different cohorts   . The CFHY402H allele (rs1061170, "
ABSTRACT: Age-related macular degeneration (AMD) is the most common cause of blindness among the elderly, especially in Western countries. Although the prevalence, risk factors, and clinical course of the disease are well described, its pathogenesis is not entirely elucidated. AMD is associated with a variety of biochemical abnormalities, including complement components deposition in the retinal pigment epithelium-Bruch's membrane-choriocapillaris complex. Although the complement system (CS) is increasingly recognized as mediating important roles in retinal biology, its particular role in AMD pathogenesis has not been precisely defined. Unrestricted activation of the CS following injury may directly damage retinal tissue and recruit immune cells to the vicinity of active complement cascades, therefore detrimentally causing bystander damage to surrounding cells and tissues. On the other hand, recent evidence supports the notion that an active complement pathway is a necessity for the normal maintenance of the neurosensory retina. In this scenario, complement activation appears to have beneficial effect as it promotes cell survival and tissue remodeling by facilitating the rapid removal of dying cells and resulting cellular debris, thus demonstrating anti-inflammatory and neuroprotective activities. In this review, we discuss both the beneficial and detrimental roles of CS in degenerative retina, focusing on the diverse aspects of CS functions that may promote or inhibit macular disease.Research Journal of Immunology 09/2014; 2014:483960. DOI:10.1155/2014/483960