scholarly journals Role of educational attainment, cognitive performance and intelligence in neurodegeneration: a bidirectional Mendelian randomization study

2019 ◽  
Author(s):  
Sandeep Grover ◽  
Keyword(s):  
Educational Attainment ◽  
Neurodegenerative Diseases ◽  
Cognitive Performance ◽  
Mendelian Randomization ◽  
Late Onset ◽  
Age Related Macular Degeneration ◽  
European Ancestry ◽  
Reverse Causality ◽  
Age Related

AbstractI examined the potential bi-directional causality between educational attainment (EA) (n = 766,345) and age related macular degeneration (AMD) (cases (n) =16144, controls (n) =17832) using the summary GWAS datasets on individuals with European ancestry. I used datasets on other late-onset neurodegenerative diseases including Alzheimer’s disease (AD) and Parkinson’s disease (PD) as controls to validate the findings. A risky effect of EA on AMD was observed (OR=1.318, 95% CI=1.080 −1.610, P=0.0068) after ruling out potential pleiotropy and absence of reverse causality. I further replicated previously observed protective and risky causal associations of EA with AD and PD.

scholarly journals Bidirectional Mendelian randomization analysis of shared genetic signals between coexisting neurodegenerative disorders to decipher underlying causal pathways

2019 ◽  
Author(s):  
Sandeep Grover ◽  
Keyword(s):  
Multiple Sclerosis ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neurodegenerative Diseases ◽  
Macular Degeneration ◽  
Neurodegenerative Disorders ◽  
Mendelian Randomization ◽  
Age Related Macular Degeneration ◽  
European Ancestry ◽  
Age Related

ABSTRACTOBJECTIVETo investigate whether coexistence of various neurodegenerative disorders is coincidental or biologically connected.DESIGNTwo sample Mendelian randomization using summary effect estimatesSETTINGGenetic data taken on various neurodegenerative disorders from various cohorts comprising individuals predominantly of European ancestry.PARTICIPANTSInternational Genomics of Alzheimer’s patients (IGAP), project MinE, International Age-related Macular Degeneration Consortium (IAMDGC), International Multiple Sclerosis Genetics Consortium (IMSGC), International Parkinson’s Disease Genomics Consortium (IPDGC)MAIN OUTCOME MEASURESAlzheimer’s disease (AD), Amyotrophic lateral sclerosis (ALS), Age related macular degeneration (AMD), Multiple sclerosis (MS) and Parkinson’s disease (PD).RESULTSA Bonferroni corrected threshold of P=0.005 was considered to be significant, and P<0.05 was considered suggestive of evidence for a potential association. I observed a risky effect of PD on ALS (OR = 1.126, 95% CI = 1.059-1.198, P = 0.005). Using AD as exposure and PD as outcome, I observed a risky effect of AD on PD using all the MR methods with strongest results using MBE method (OR = 2.072, 95% CI = 1.006-4.028, P = 0.0416). Genetic predisposition to AD was further observed to be a risky for AMD (OR = 1.759, 95% CI = 1.040-1.974, P = 0.0363). On the contrary, AMD was observed to be strongly protective towards MS (OR = 0.861, 95% CI = 0.776-0.955, P = 0.0059).CONCLUSIONSMy findings are consistent with the previously observed relative occurrence of co-existing neurodegenerative diseases or overlapping symptoms among neurodegenerative diseases.

scholarly journals Casual Effect of Serum Lipid Biomarkers On Early Age-Related Macular Degeneration Using Mendelian Randomization

2021 ◽  
Author(s):  
Fen-Fen Li ◽  
Yuqin Wang ◽  
Qi Chen ◽  
Lue Xiang ◽  
Feng-Qin Rao ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Serum Lipid ◽  
Mendelian Randomization ◽  
Density Lipoprotein ◽  
Lipid Biomarkers ◽  
Age Related Macular Degeneration ◽  
Lipoprotein Cholesterol ◽  
European Ancestry ◽  
Age Related ◽  
Increased Risk

Abstract Background Age-related macular degeneration (AMD) is one of the major causes of vision loss. Early AMD needs to be taken seriously, whereas lipid biomarkers’ casual effects on early AMD remain unclear. Methods In this study, a two-sample Mendelian randomization (MR) analysis was performed to systematically assess the causal relationships between seven serum lipid biomarkers, consisting of apolipoprotein A (ApoA), apolipoprotein B (ApoB), total cholesterol (CHOL), high-density lipoprotein cholesterol (HDL-C), direct low-density lipoprotein cholesterol (LDL-C), lipoprotein A [Lp(a)], and triglycerides (TG), and the risk of early AMD. Totally, 14,034 cases and 91,214 controls of European ancestry were included in the analysis (Number of SNPs = 11,304,110). Results MR estimates showed that a higher HDL-C level was strongly associated with increased risk of early AMD (OR = 1.25, 95% CI: 1.15-1.35, P = 2.61 × 10−8). In addition, the level of ApoA was also positively associated with the risk of early AMD (OR = 2.04, 95% CI: 1.50-2.77, P = 6.27 × 10−6). Conversely, higher LDL-C levels significantly decreased the risk of early AMD (OR = 0.90, 95% CI: 0.85-0.96, P = 2.03 × 10−3). In addition to LDL-C, higher levels of ApoB and TG were found to be positively associated with early AMD risk. Sensitivity analyses further supported these associations. Moreover, multivariable MR analyses, adjusting for the effects of correlated lipid biomarkers yielded similar results. Conclusion This study addresses the question of causality relationships that elevated circulating HDL-C/ApoA levels and increased risk of early AMD, whereas LDL-C, ApoB, and TG specifically reduce the risk of early AMD. These findings contribute to our better understanding of the role of lipid metabolism in drusen formation, particularly in early AMD development.

scholarly journals Reactive Oxygen Species-Mediated Damage of Retinal Neurons: Drug Development Targets for Therapies of Chronic Neurodegeneration of the Retina

2018 ◽  
Vol 19 (11) ◽  
pp. 3362 ◽  
Author(s):  
Landon Rohowetz ◽  
Jacob Kraus ◽  
Peter Koulen
Keyword(s):  
Reactive Oxygen Species ◽  
Neurodegenerative Diseases ◽  
Reactive Oxygen ◽  
Age Related Macular Degeneration ◽  
Oxygen Species ◽  
Treatment And Prevention ◽  
Age Related ◽  
Recent Developments ◽  
Low Levels

The significance of oxidative stress in the development of chronic neurodegenerative diseases of the retina has become increasingly apparent in recent years. Reactive oxygen species (ROS) are free radicals produced at low levels as a result of normal cellular metabolism that are ultimately metabolized and detoxified by endogenous and exogenous mechanisms. In the presence of oxidative cellular stress, ROS are produced in excess, resulting in cellular injury and death and ultimately leading to tissue and organ dysfunction. Recent studies have investigated the role of excess ROS in the pathogenesis and development of chronic neurodegenerative diseases of the retina including glaucoma, diabetic retinopathy, and age-related macular degeneration. Findings from these studies are promising insofar as they provide clear rationales for innovative treatment and prevention strategies of these prevalent and disabling diseases where currently therapeutic options are limited. Here, we briefly outline recent developments that have contributed to our understanding of the role of ROS in the pathogenesis of chronic neurodegenerative diseases of the retina. We then examine and analyze the peer-reviewed evidence in support of ROS as targets for therapy development in the area of chronic neurodegeneration of the retina.

scholarly journals Sleep, pain, and neurodegeneration: A Mendelian randomization study

2021 ◽  
Author(s):  
Sandeep Grover ◽  
Manu Sharma ◽  
Keyword(s):  
Multiple Sclerosis ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Risk Factor ◽  
Macular Degeneration ◽  
Mendelian Randomization ◽  
Age Related Macular Degeneration ◽  
Suggestive Evidence ◽  
Age Related

AbstractObjectiveTo examine whether sleep and pain-related traits have a causal effect on the risk of neurodegeneration.DesignTwo-sample Mendelian randomization using an inverse-variance weighted (IVW) estimate of the summary effect estimates.SettingGenetic data on sleep and pain-related traits and neurodegenerative disorders (NDD) from various cohorts comprising individuals predominantly of European ancestry.ParticipantsParticipants from the International Sleep Genetic Epidemiology Consortium (ISGEC), UK Biobank sleep and chronotype research group, International Genomics of Alzheimer’s patients (IGAP), project MinE, International Age-related Macular Degeneration Consortium (IAMDGC), International Multiple Sclerosis Genetics Consortium (IMSGC), International Parkinson’s Disease Genomics Consortium (IPDGC)ExposuresSelf-reported chronotype (CHR), morning preference (MP), insomnia symptoms (INS), sleep duration (SP), short sleep (SS), long sleep (LS), and multisite chronic pain (MCP)Main outcome measuresAge-related macular degeneration (AMD), Alzheimer’s disease (AD), Amyotrophic lateral sclerosis (ALS), Multiple sclerosis (MS), and Parkinson’s disease (PD)ResultsWe considered a threshold of P=0.00142 as significant accounting for multiple testing, and P<0.05 was considered to be suggestive evidence for a potential association. Using direct MR, MP was observed as the strongest risk factor for AMD (ORIVW = 1.19, 95% CI 1.08, 1.32, P = 0.00073). We observed suggestive evidence of influence of different sleep traits on neurodegeneration: CHR on AMD (ORIVW = 1.27, 95% CI 1.08, 1.49, P = 0.0034), SS on AD (ORIVW 1.26, 95% CI 1.08, 1.46, P = 0.0044), and INS on ALS (ORIVW 1.55, 95% CI 1.12, 2.14, P = 0.0123). The association of SS with AD was, however, lost after the exclusion of overlapping UKB samples. Using pain as exposure, our study failed to observe any role of pain in neurodegeneration. Results were largely robust to reverse causal analyses and sensitivity analyses accounting for horizontal pleiotropy.ConclusionsOur study highlighted the role of morning preference as a risk factor for AMD and provided suggestive evidence of different sleep traits on a wide spectrum of neurodegenerative diseases.

scholarly journals The role of linoleic acid in asthma and inflammatory markers: a Mendelian randomization study

2019 ◽  
Vol 110 (3) ◽  
pp. 685-690 ◽  
Author(s):  
Jie V Zhao ◽  
C Mary Schooling
Keyword(s):  
Linoleic Acid ◽  
Blood Cell ◽  
White Blood Cell ◽  
Genetic Variants ◽  
Mendelian Randomization ◽  
European Ancestry ◽  
Uk Biobank ◽  
Reverse Causality ◽  
The Uk

ABSTRACT Background Asthma is a common respiratory disease, possibly caused by autoimmunity. Linoleic acid (LA), the main n–6 (ω-6) PUFA from widely used vegetable oils, is thought to suppress immune responses that might have benefits for asthma. However, this question has not been examined in randomized controlled trials. Objectives To obtain unconfounded estimates, we assessed how genetically predicted LA affected asthma using 2-sample Mendelian randomization. We also examined its role in white blood cell traits (eosinophil, neutrophil, and low monocyte counts) identified as potential causal factors in asthma. Methods We used 18 uncorrelated, genome-wide significant genetic variants to predict LA, which we applied to a large genetic case (n = 19,954)–control (n = 107,715) study of asthma, to the UK Biobank (408,961 people of European ancestry with 26,332 asthma cases), and for white blood cell traits to the UK Biobank. We also repeated the analysis on asthma using 29 replicated, functionally relevant genetic variants. In addition, we examined the role of asthma in LA to assess reverse causality. Results Genetically predicted LA was associated with lower risk of asthma (OR: 0.89 per SD increase in LA; 95% CI: 0.85, 0.93), with no association of asthma with LA. Genetically predicted LA was associated with lower eosinophil count (−0.03; 95% CI: −0.061, −0.004) and lower neutrophil count (−0.04; 95% CI: −0.057, −0.023). These estimates were robust to different selections of genetic variants and sensitivity analyses. Conclusions LA might protect against asthma possibly via white blood cell traits, with relevance to the identification of effective new interventions for asthma.

Caution against examining the role of reverse causality in Mendelian Randomization

2021 ◽  
Author(s):  
Sharon M. Lutz ◽  
Ann Chen Wu ◽  
John E. Hokanson ◽  
Stijn Vansteelandt ◽  
Christoph Lange
Keyword(s):  
Mendelian Randomization ◽  
Reverse Causality

scholarly journals Complement C5 is not critical for the formation of sub-RPE deposits in Efemp1 mutant mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Donita L. Garland ◽  
Eric A. Pierce ◽  
Rosario Fernandez-Godino
Keyword(s):  
Macular Degeneration ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Deposit Formation ◽  
Genetic Ablation ◽  
Age Related ◽  
Complement Dysregulation

AbstractThe complement system plays a role in the formation of sub-retinal pigment epithelial (RPE) deposits in early stages of age-related macular degeneration (AMD). But the specific mechanisms that connect complement activation and deposit formation in AMD patients are unknown, which limits the development of efficient therapies to reduce or stop disease progression. We have previously demonstrated that C3 blockage prevents the formation of sub-RPE deposits in a mouse model of EFEMP1-associated macular degeneration. In this study, we have used double mutant Efemp1R345W/R345W:C5-/- mice to investigate the role of C5 in the formation of sub-RPE deposits in vivo and in vitro. The data revealed that the genetic ablation of C5 does not eliminate the formation of sub-RPE deposits. Contrarily, the absence of C5 in RPE cultures promotes complement dysregulation that results in increased activation of C3, which likely contributes to deposit formation even in the absence of EFEMP1-R345W mutant protein. The results also suggest that genetic ablation of C5 alters the extracellular matrix turnover through an effect on matrix metalloproteinases in RPE cell cultures. These results confirm that C3 rather than C5 could be an effective therapeutic target to treat early AMD.

scholarly journals Exacerbation of AMD Phenotype in Lasered CNV Murine Model by Dysbiotic Oral Pathogens

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 309
Author(s):  
Pachiappan Arjunan ◽  
Radhika Swaminathan ◽  
Jessie Yuan ◽  
Mohamed Elashiry ◽  
Amany Tawfik ◽  
...  
Keyword(s):  
Murine Model ◽  
Retinal Thickness ◽  
Age Related Macular Degeneration ◽  
Periodontal Pathogen ◽  
Fundus Photography ◽  
Mouse Retina ◽  
Rrna Gene ◽  
Age Related ◽  
Periodontal Infection

Emerging evidence underscores an association between age-related macular degeneration (AMD) and periodontal disease (PD), yet the biological basis of this linkage and the specific role of oral dysbiosis caused by PD in AMD pathophysiology remains unclear. Furthermore, a simple reproducible model that emulates characteristics of both AMD and PD has been lacking. Hence, we established a novel AMD+PD murine model to decipher the potential role of oral infection (ligature-enhanced) with the keystone periodontal pathogen Porphyromonas gingivalis, in the progression of neovasculogenesis in a laser-induced choroidal-neovascularization (Li-CNV) mouse retina. By a combination of fundus photography, optical coherence tomography, and fluorescein angiography, we documented inflammatory drusen-like lesions, reduced retinal thickness, and increased vascular leakage in AMD+PD mice retinae. H&E further confirmed a significant reduction of retinal thickness and subretinal drusen-like deposits. Immunofluorescence microscopy revealed significant induction of choroidal/retinal vasculogenesis in AMD+PD mice. qPCR identified increased expression of oxidative-stress, angiogenesis, pro-inflammatory mediators, whereas antioxidants and anti-inflammatory genes in AMD+PD mice retinae were notably decreased. Through qPCR, we detected Pg and its fimbrial 16s-RrNA gene expression in the AMD+PD mice retinae. To sum-up, this is the first in vivo study signifying a role of periodontal infection in augmentation of AMD phenotype, with the aid of a pioneering AMD+PD murine model established in our laboratory.

scholarly journals FHL-1 interacts with human RPE cells through the α5β1 integrin and confers protection against oxidative stress

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rawshan Choudhury ◽  
Nadhim Bayatti ◽  
Richard Scharff ◽  
Ewa Szula ◽  
Viranga Tilakaratna ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Fate ◽  
Retinal Pigment ◽  
Factor H ◽  
Age Related Macular Degeneration ◽  
Bruch's Membrane ◽  
Bruch’S Membrane ◽  
Rpe Cells ◽  
Age Related

AbstractRetinal pigment epithelial (RPE) cells that underlie the neurosensory retina are essential for the maintenance of photoreceptor cells and hence vision. Interactions between the RPE and their basement membrane, i.e. the inner layer of Bruch’s membrane, are essential for RPE cell health and function, but the signals induced by Bruch’s membrane engagement, and their contributions to RPE cell fate determination remain poorly defined. Here, we studied the functional role of the soluble complement regulator and component of Bruch’s membrane, Factor H-like protein 1 (FHL-1). Human primary RPE cells adhered to FHL-1 in a manner that was eliminated by either mutagenesis of the integrin-binding RGD motif in FHL-1 or by using competing antibodies directed against the α5 and β1 integrin subunits. These short-term experiments reveal an immediate protein-integrin interaction that were obtained from primary RPE cells and replicated using the hTERT-RPE1 cell line. Separate, longer term experiments utilising RNAseq analysis of hTERT-RPE1 cells bound to FHL-1, showed an increased expression of the heat-shock protein genes HSPA6, CRYAB, HSPA1A and HSPA1B when compared to cells bound to fibronectin (FN) or laminin (LA). Pathway analysis implicated changes in EIF2 signalling, the unfolded protein response, and mineralocorticoid receptor signalling as putative pathways. Subsequent cell survival assays using H2O2 to induce oxidative stress-induced cell death suggest hTERT-RPE1 cells had significantly greater protection when bound to FHL-1 or LA compared to plastic or FN. These data show a non-canonical role of FHL-1 in protecting RPE cells against oxidative stress and identifies a novel interaction that has implications for ocular diseases such as age-related macular degeneration.

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