Aβ-accelerated neurodegeneration caused by Alzheimer’s-associated ACE variant R1279Q is rescued by angiotensin system inhibition in mice

2020 ◽  
Vol 12 (563) ◽  
pp. eaaz2541
Author(s):  
Leah K. Cuddy ◽  
Dmitry Prokopenko ◽  
Eric P. Cunningham ◽  
Ross Brimberry ◽  
Peter Song ◽  
...  
Keyword(s):  
Memory Impairment ◽  
Autosomal Dominant ◽  
Association Studies ◽  
Genome Wide Association Studies ◽  
Angiotensin System ◽  
Genome Wide ◽  
Amyloid Aβ ◽  
Β Amyloid ◽  
5Xfad Mice ◽  
Coding Variants

Recent genome-wide association studies identified the angiotensin-converting enzyme gene (ACE) as an Alzheimer’s disease (AD) risk locus. However, the pathogenic mechanism by which ACE causes AD is unknown. Using whole-genome sequencing, we identified rare ACE coding variants in AD families and investigated one, ACE1 R1279Q, in knockin (KI) mice. Similar to AD, ACE1 was increased in neurons, but not microglia or astrocytes, of KI brains, which became elevated further with age. Angiotensin II (angII) and angII receptor AT1R signaling were also increased in KI brains. Autosomal dominant neurodegeneration and neuroinflammation occurred with aging in KI hippocampus, which were absent in the cortex and cerebellum. Female KI mice exhibited greater hippocampal electroencephalograph disruption and memory impairment compared to males. ACE variant effects were more pronounced in female KI mice, suggesting a mechanism for higher AD risk in women. Hippocampal neurodegeneration was completely rescued by treatment with brain-penetrant drugs that inhibit ACE1 and AT1R. Although ACE variant-induced neurodegeneration did not depend on β-amyloid (Aβ) pathology, amyloidosis in 5XFAD mice crossed to KI mice accelerated neurodegeneration and neuroinflammation, whereas Aβ deposition was unchanged. KI mice had normal blood pressure and cerebrovascular functions. Our findings strongly suggest that increased ACE1/angII signaling causes aging-dependent, Aβ-accelerated selective hippocampal neuron vulnerability and female susceptibility, hallmarks of AD that have hitherto been enigmatic. We conclude that repurposed brain-penetrant ACE inhibitors and AT1R blockers may protect against AD.

scholarly journals Localization of a feline autosomal dominant dwarfism locus: a novel model of chondrodysplasia

2019 ◽  
Author(s):  
L.A. Lyons ◽  
D.B. Fox ◽  
K.L. Chesney ◽  
L.G. Britt ◽  
R.M. Buckley ◽  
...  
Keyword(s):  
Autosomal Dominant ◽  
Association Studies ◽  
Genome Wide Association Studies ◽  
Biomedical Model ◽  
Genetic Approach ◽  
Domestic Cats ◽  
Novel Gene ◽  
Genome Wide ◽  
Coding Variants ◽  
Novel Model

AbstractDespite the contribution of a few major genes for disproportionate dwarfism in humans, many dwarf patients are yet genetically undiagnosed. In domestic cats, disproportionate dwarfism has led to the development of a defined breed, the Munchkin or Minuet. This study examined the genetic aspects of feline dwarfism to consider cats as a new biomedical model. DNA from dwarf cats was genetically analyzed using parentage, linkage, and genome-wide association studies as well as whole genome sequencing. Each genetic approach localized the dwarfism phenotype to a region on cat chromosome B1. No coding variants suspected as causal for the feline dwarfism were identified but a critical region of ∼5.7 Mb from B1:170,278,183-175,975,857 was defined, which implicates a novel gene controlling disproportionate dwarfism. A yet unidentified but novel gene variant, likely structural or regulatory, produces disproportionate dwarfism in cats, which may define undiagnosed human patients.

scholarly journals Challenges and progress in interpretation of non-coding genetic variants associated with human disease

2017 ◽  
Vol 242 (13) ◽  
pp. 1325-1334 ◽  
Author(s):  
Yizhou Zhu ◽  
Cagdas Tazearslan ◽  
Yousin Suh
Keyword(s):  
Molecular Mechanisms ◽  
Target Genes ◽  
Disease Risk ◽  
Association Studies ◽  
Genome Wide Association ◽  
Genome Wide Association Studies ◽  
Genetic Associations ◽  
Functional Interpretation ◽  
Genome Wide ◽  
Coding Variants

Genome-wide association studies have shown that the far majority of disease-associated variants reside in the non-coding regions of the genome, suggesting that gene regulatory changes contribute to disease risk. To identify truly causal non-coding variants and their affected target genes remains challenging but is a critical step to translate the genetic associations to molecular mechanisms and ultimately clinical applications. Here we review genomic/epigenomic resources and in silico tools that can be used to identify causal non-coding variants and experimental strategies to validate their functionalities. Impact statement Most signals from genome-wide association studies (GWASs) map to the non-coding genome, and functional interpretation of these associations remained challenging. We reviewed recent progress in methodologies of studying the non-coding genome and argued that no single approach allows one to effectively identify the causal regulatory variants from GWAS results. By illustrating the advantages and limitations of each method, our review potentially provided a guideline for taking a combinatorial approach to accurately predict, prioritize, and eventually experimentally validate the causal variants.

scholarly journals Sequencing of over 100,000 individuals identifies multiple genes and rare variants associated with Crohns disease susceptibility

2021 ◽  
Author(s):  
Aleksejs Sazonovs ◽  
Christine R Stevens ◽  
Guhan R Venkataraman ◽  
Kai Yuan ◽  
Brandon Avila ◽  
...  
Keyword(s):  
Rare Variants ◽  
Disease Risk ◽  
Sequence Data ◽  
Association Studies ◽  
Genome Wide Association Studies ◽  
Crohns Disease ◽  
Biological Targets ◽  
Genome Wide ◽  
Coding Variants ◽  
First Time

Genome-wide association studies (GWAS) have identified hundreds of loci associated with Crohns disease (CD); however, as with all complex diseases, deriving pathogenic mechanisms from these non-coding GWAS discoveries has been challenging. To complement GWAS and better define actionable biological targets, we analysed sequence data from more than 30,000 CD cases and 80,000 population controls. We observe rare coding variants in established CD susceptibility genes as well as ten genes where coding variation directly implicates the gene in disease risk for the first time.

Identification of rare coding variants in TYK2 protective for rheumatoid arthritis in the Japanese population and their effects on cytokine signalling

2019 ◽  
Vol 78 (8) ◽  
pp. 1062-1069 ◽  
Author(s):  
Tomoki Motegi ◽  
Yuta Kochi ◽  
Koichi Matsuda ◽  
Michiaki Kubo ◽  
Kazuhiko Yamamoto ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Japanese Population ◽  
Association Studies ◽  
Kinase Domain ◽  
Genome Wide Association Studies ◽  
Risk Variant ◽  
Coding Regions ◽  
Genome Wide ◽  
Reporter Assays ◽  
Coding Variants

ObjectiveAlthough genome-wide association studies (GWAS) have identified approximately 100 loci for rheumatoid arthritis (RA), the disease mechanisms are not completely understood. We evaluated the pathogenesis of RA by focusing on rare coding variants.MethodsThe coding regions of 98 candidate genes identified by GWAS were sequenced in 2294 patients with RA and 4461 controls in Japan. An association analysis was performed using cases and controls for variants, genes and domains of TYK2. Cytokine responses for two associated variants (R231W, rs201917359; and R703W, rs55882956) in TYK2 as well as a previously reported risk variant (P1004A, rs34536443) for multiple autoimmune diseases were evaluated by reporter assays.ResultsA variant in TYK2 (R703W) showed a suggestive association (p=5.47×10−8, OR=0.48). We observed more accumulation of rare coding variants in controls in TYK2 (p=3.94×10−12, OR=0.56). The four-point-one, ezrin, radixin, moesin (FERM; 2.14×10−3, OR=0.66) and pseudokinase domains (1.63×10−8, OR=0.52) of TYK2 also showed enrichment of variants in controls. R231W in FERM domain especially reduced interleukin (IL)-6 and interferon (IFN)-γ signalling, whereas P1104A in kinase domain reduced IL-12, IL-23 and IFN-α signalling. R703W in pseudokinase domain reduced cytokine signals similarly to P1104A, but the effects were weaker than those of P1104A.ConclusionsThe FERM and pseudokinase domains in TYK2 were associated with the risk of RA in the Japanese population. Variants in TYK2 had different effects on cytokine signalling, suggesting that the regulation of selective cytokine signalling is a target for RA treatment.

scholarly journals GARFIELD - GWAS Analysis of Regulatory or Functional Information Enrichment with LD correction

2016 ◽  
Author(s):  
Valentina Iotchkova ◽  
Graham R.S. Ritchie ◽  
Matthias Geihs ◽  
Sandro Morganella ◽  
Josine L. Min ◽  
...  
Keyword(s):  
Association Studies ◽  
R Package ◽  
Genome Wide Association Studies ◽  
Protein Coding ◽  
Functional Annotations ◽  
Novel Approach ◽  
Genome Wide ◽  
Functional Consequences ◽  
Genomic Regions ◽  
Coding Variants

Loci discovered by genome-wide association studies (GWAS) predominantly map outside protein-coding genes. The interpretation of functional consequences of non-coding variants can be greatly enhanced by catalogs of regulatory genomic regions in cell lines and primary tissues. However, robust and readily applicable methods are still lacking to systematically evaluate the contribution of these regions to genetic variation implicated in diseases or quantitative traits. Here we propose a novel approach that leverages GWAS findings with regulatory or functional annotations to classify features relevant to a phenotype of interest. Within our framework, we account for major sources of confounding that current methods do not offer. We further assess enrichment statistics for 27 GWAS traits within regulatory regions from the ENCODE and Roadmap projects. We characterise unique enrichment patterns for traits and annotations, driving novel biological insights. The method is implemented in standalone software and R package to facilitate its application by the research community.

scholarly journals Random glucose GWAS in 493,036 individuals provides insights into diabetes pathophysiology, complications and treatment stratification

2021 ◽  
Author(s):  
Vasiliki Lagou ◽  
Longda Jiang ◽  
Anna Ulrich ◽  
Liudmila Zudina ◽  
Karla Sofia Gutiérrez González ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Association Studies ◽  
Meta Analysis ◽  
Mendelian Randomisation ◽  
Genome Wide Association Studies ◽  
Functional Studies ◽  
Genome Wide ◽  
Dynamics Simulations ◽  
Coding Variants ◽  
Glycaemic Traits

Homeostatic control of blood glucose requires different physiological responses in the fasting and post-prandial states. We reasoned that glucose measurements under non-standardised conditions (random glucose, RG) may capture diverse glucoregulatory processes more effectively than previous genome-wide association studies (GWAS) of fasting glycaemia or after standardised glucose loads. Through GWAS meta-analysis of RG in 493,036 individuals without diabetes of diverse ethnicities we identified 128 associated loci represented by 162 distinct signals, including 14 with sex-dimorphic effects, 9 discovered through trans-ethnic analysis, and 70 novel signals for glycaemic traits. Novel RG loci were particularly enriched in expression in the ileum and colon, indicating a prominent role for the gastrointestinal tract in the control of blood glucose. Functional studies and molecular dynamics simulations of coding variants of GLP1R, a well-established type 2 diabetes treatment target, provided a genetic framework for optimal selection of GLP-1R agonist therapy. We also provided new evidence from Mendelian randomisation that lung function is modulated by blood glucose and that pulmonary dysfunction is a diabetes complication. Thus, our approach based on RG GWAS provided wide-ranging insights into the biology of glucose regulation, diabetes complications and the potential for treatment stratification.

Genetics of ischemic stroke: where are we now?

2011 ◽  
Vol 152 (12) ◽  
pp. 455-463 ◽  
Author(s):  
Anita Maász ◽  
Zoltán Szolnoki ◽  
László Balikó ◽  
Béla Melegh
Keyword(s):  
Ischemic Stroke ◽  
Genetic Variants ◽  
Association Studies ◽  
Renin Angiotensin System ◽  
Cerebrovascular Diseases ◽  
Genome Wide Association Studies ◽  
Angiotensin System ◽  
New Approach ◽  
Genome Wide ◽  
Genes Encoding

As stroke is the third leading cause of death after heart failure and tumors worldwide, cerebrovascular diseases reached substantial attention. In the past few years, significant progression has been seen in identification of genetic variants in the background of stroke and other cerebrovascular and cardiovascular events. Examination of these variants is a new approach to recognize pathogenesis of disorders that hopefully helps in future prevention and prospects of screening and, optimistically, it contributes to special care of patients susceptible for stroke. In the background of ischemic stroke several genetic variants have been identified, which localize in genes encoding proteins involved in hemostasis, renin-angiotensin system and lipid metabolism. The number of these variants exponentially increases permanently due to rapid spreading of genome wide association studies. The goal of this review is to summarize the results of genetic studies on ischemic stroke. Here the authors focus on genetic variants which can have major role in personalized medicine and prevention of stroke. Orv. Hetil., 2011, 152, 455–463.

scholarly journals Mapping genomic loci prioritises genes and implicates synaptic biology in schizophrenia

2020 ◽  
Author(s):  
◽  
Stephan Ripke ◽  
James TR Walters ◽  
Michael C O'Donovan
Keyword(s):  
Developmental Disorder ◽  
Association Studies ◽  
Cell Types ◽  
Genome Wide Association Studies ◽  
Biological Processes ◽  
Neuronal Function ◽  
Protein Coding ◽  
Risk Alleles ◽  
Genome Wide ◽  
Coding Variants

Schizophrenia is a psychiatric disorder whose pathophysiology is largely unknown. It has a heritability of 60-80%, much of which is attributable to common risk alleles, suggesting genome-wide association studies can inform our understanding of aetiology. Here, in 69,369 people with schizophrenia and 236,642 controls, we report common variant associations at 270 distinct loci. Using fine-mapping and functional genomic data, we prioritise 19 genes based on protein-coding or UTR variation, and 130 genes in total as likely to explain these associations. Fine-mapped candidates were enriched for genes associated with rare disruptive coding variants in people with schizophrenia, including the glutamate receptor subunit GRIN2A and transcription factor SP4, and were also enriched for genes implicated by such variants in autism and developmental disorder. Associations were concentrated in genes expressed in CNS neurons, both excitatory and inhibitory, but not other tissues or cell types, and implicated fundamental processes related to neuronal function, particularly synaptic organisation, differentiation and transmission. We identify biological processes of pathophysiological relevance to schizophrenia, show convergence of common and rare variant associations in schizophrenia and neurodevelopmental disorders, and provide a rich resource of priority genes and variants to advance mechanistic studies.

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