scholarly journals Immunoglobulin A Nephropathy: Advances in Understanding of Pathogenesis and Treatment

2018 ◽  
Vol 47 (Suppl. 1) ◽  
pp. 43-52 ◽  
Author(s):  
Richard A. Lafayette ◽  
Ellie Kelepouris
Keyword(s):  
Iga Nephropathy ◽  
Association Studies ◽  
Treatment Options ◽  
Immunoglobulin A ◽  
Genome Wide Association Studies ◽  
Genome Wide ◽  
Wide Range ◽  
New Treatment ◽  
Stage Renal Disease ◽  
End Stage

Background: Immunoglobulin A (IgA) nephropathy is the most common form of primary glomerulonephritis and has clinical associations with a wide range of inflammatory and infectious diseases. There is a substantial variation in clinical course and outcomes, with many patients not diagnosed until they present with sequelae, which may include gross hematuria, hypertension, renal insufficiency, and/or significant proteinuria. Treatment options are currently limited and directed mainly toward control of these sequelae and have limited ability to reduce the incidence of end-stage renal disease or treat the primary IgA defect. Summary: Growing knowledge about the pathogenesis of IgA nephropathy and research into its genetic basis are helping to elucidate the course of this widely variable disease. IgA accumulation in the kidneys is thought to be the result of a number of different pathways in a “multi-hit” process that includes an initial traumatic trigger (often infection related) and subsequent memory responses that are amplified in those with a genetic predisposition to the disease and lead to an inflammatory response in susceptible individuals. Genome-wide association studies are providing new insights into the genetic variance of this autoimmune disease and are yielding information that may address both its causes and consequences. Key Messages: New treatment approaches are urgently required for the management of patients with IgA nephropathy. Novel interventions based around its inflammatory nature and “multi-hit” pathogenesis are being investigated to potentially limit disease progression.

scholarly journals Cellular Signaling and Production of Galactose-Deficient IgA1 in IgA Nephropathy, an Autoimmune Disease

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Colin Reily ◽  
Hiroyuki Ueda ◽  
Zhi-Qiang Huang ◽  
Jiri Mestecky ◽  
Bruce A. Julian ◽  
...  
Keyword(s):  
Iga Nephropathy ◽  
Immune Complexes ◽  
Association Studies ◽  
Immunoglobulin A ◽  
Specific Treatment ◽  
Genome Wide Association Studies ◽  
Glomerular Injury ◽  
Stage Renal Disease ◽  
End Stage ◽  
Disease Specific

Immunoglobulin A (IgA) nephropathy (IgAN), the leading cause of primary glomerulonephritis, is characterized by IgA1-containing immunodeposits in the glomeruli. IgAN is a chronic disease, with up to 40% of patients progressing to end-stage renal disease, with no disease-specific treatment. Multiple studies of the origin of the glomerular immunodeposits have linked elevated circulating levels of aberrantly glycosylated IgA1 (galactose-deficient in someO-glycans; Gd-IgA1) with formation of nephritogenic Gd-IgA1-containing immune complexes. Gd-IgA1 is recognized as an autoantigen in susceptible individuals by anti-glycan autoantibodies, resulting in immune complexes that may ultimately deposit in the kidney and induce glomerular injury. Genetic studies have revealed that an elevated level of Gd-IgA1 in the circulation of IgAN patients is a hereditable trait. Moreover, recent genome-wide association studies have identified several immunity-related loci that associated with IgAN. Production of Gd-IgA1 by IgA1-secreting cells of IgAN patients has been attributed to abnormal expression and activity of several key glycosyltransferases. Substantial evidence is emerging that abnormal signaling in IgA1-producing cells is related to the production of Gd-IgA1. As Gd-IgA1 is the key autoantigen in IgAN, understanding the genetic, biochemical, and environmental aspects of the abnormal signaling in IgA1-producing cells will provide insight into possible targets for future disease-specific therapy.

scholarly journals Polymorphism in the GATM Locus Associated with Dialysis-Independent Chronic Kidney Disease but Not Dialysis-Dependent Kidney Failure

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 834
Author(s):  
Špela Šalamon ◽  
Sebastjan Bevc ◽  
Robert Ekart ◽  
Radovan Hojs ◽  
Uroš Potočnik
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Kidney Failure ◽  
Association Studies ◽  
Genetic Difference ◽  
Genome Wide Association Studies ◽  
Healthy Controls ◽  
Genome Wide ◽  
Stage Renal Disease ◽  
End Stage

The ten most statistically significant estimated glomerular filtration rate (eGFRcrea)-associated loci from genome-wide association studies (GWAs) are tested for associations with chronic kidney disease (CKD) in 208 patients, including dialysis-independent CKD and dialysis-dependent end-stage renal disease (kidney failure). The allele A of intergenic SNP rs2453533 (near GATM) is more frequent in dialysis-independent CKD patients (n = 135, adjusted p = 0.020) but not dialysis-dependent kidney failure patients (n = 73) compared to healthy controls (n = 309). The allele C of intronic SNP rs4293393 (UMOD) is more frequent in healthy controls (adjusted p = 0.042) than in CKD patients. The Allele T of intronic SNP rs9895661 (BCAS3) is associated with decreased eGFRcys (adjusted p = 0.001) and eGFRcrea (adjusted p = 0.017). Our results provide further evidence of a genetic difference between dialysis-dialysis-independent CKD and dialysis-dependent kidney failure, and add the GATM gene locus to the list of loci associated only with dialysis-independent CKD. GATM risk allele carriers in the dialysis-independent group may have a genetic susceptibility to higher creatinine production rather than increased serum creatinine due to kidney malfunction, and therefore, do not progress to dialysis-dependent kidney failure. When using eGFRcrea for CKD diagnosis, physicians might benefit from information about creatinine-increasing loci.

scholarly journals High Elmo1 expression aggravates and low Elmo1 expression prevents diabetic nephropathy

2016 ◽  
Vol 113 (8) ◽  
pp. 2218-2222 ◽  
Author(s):  
Catherine K. Hathaway ◽  
Albert S. Chang ◽  
Ruriko Grant ◽  
Hyung-Suk Kim ◽  
Victoria J. Madden ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Transforming Growth Factor ◽  
Association Studies ◽  
Lipid Peroxides ◽  
Transforming Growth Factor Β1 ◽  
Genome Wide Association Studies ◽  
Diabetic Mice ◽  
Stage Renal Disease ◽  
End Stage

Human genome-wide association studies have demonstrated that polymorphisms in the engulfment and cell motility protein 1 gene (ELMO1) are strongly associated with susceptibility to diabetic nephropathy. However, proof of causation is lacking. To test whether modest changes in its expression alter the severity of the renal phenotype in diabetic mice, we have generated mice that are type 1 diabetic because they have the Ins2Akita gene, and also have genetically graded expression of Elmo1 in all tissues ranging in five steps from ∼30% to ∼200% normal. We here show that the Elmo1 hypermorphs have albuminuria, glomerulosclerosis, and changes in the ultrastructure of the glomerular basement membrane that increase in severity in parallel with the expression of Elmo 1. Progressive changes in renal mRNA expression of transforming growth factor β1 (TGFβ1), endothelin-1, and NAD(P)H oxidase 4 also occur in parallel with Elmo1, as do the plasma levels of cystatin C, lipid peroxides, and TGFβ1, and erythrocyte levels of reduced glutathione. In contrast, Akita type 1 diabetic mice with below-normal Elmo1 expression have reduced expression of these various factors and less severe diabetic complications. Remarkably, the reduced Elmo1 expression in the 30% hypomorphs almost abolishes the pathological features of diabetic nephropathy, although it does not affect the hyperglycemia caused by the Akita mutation. Thus, ELMO1 plays an important role in the development of type 1 diabetic nephropathy, and its inhibition could be a promising option for slowing or preventing progression of the condition to end-stage renal disease.

scholarly journals Qtlizer: comprehensive QTL annotation of GWAS results

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Matthias Munz ◽  
Inken Wohlers ◽  
Eric Simon ◽  
Tobias Reinberger ◽  
Hauke Busch ◽  
...  
Keyword(s):  
Association Studies ◽  
Housekeeping Genes ◽  
R Package ◽  
Genome Wide Association Studies ◽  
Protein Abundance ◽  
Base Pairs ◽  
Link Type ◽  
Genome Wide ◽  
Wide Range ◽  
Distance Limit

AbstractExploration of genetic variant-to-gene relationships by quantitative trait loci such as expression QTLs is a frequently used tool in genome-wide association studies. However, the wide range of public QTL databases and the lack of batch annotation features complicate a comprehensive annotation of GWAS results. In this work, we introduce the tool “Qtlizer” for annotating lists of variants in human with associated changes in gene expression and protein abundance using an integrated database of published QTLs. Features include incorporation of variants in linkage disequilibrium and reverse search by gene names. Analyzing the database for base pair distances between best significant eQTLs and their affected genes suggests that the commonly used cis-distance limit of 1,000,000 base pairs might be too restrictive, implicating a substantial amount of wrongly and yet undetected eQTLs. We also ranked genes with respect to the maximum number of tissue-specific eQTL studies in which a most significant eQTL signal was consistent. For the top 100 genes we observed the strongest enrichment with housekeeping genes (P = 2 × 10–6) and with the 10% highest expressed genes (P = 0.005) after grouping eQTLs by r2 > 0.95, underlining the relevance of LD information in eQTL analyses. Qtlizer can be accessed via https://genehopper.de/qtlizer or by using the respective Bioconductor R-package (https://doi.org/10.18129/B9.bioc.Qtlizer).

scholarly journals Genome-wide genetic data on ~500,000 UK Biobank participants

2017 ◽  
Author(s):  
Clare Bycroft ◽  
Colin Freeman ◽  
Desislava Petkova ◽  
Gavin Band ◽  
Lloyd T. Elliott ◽  
...  
Keyword(s):  
Quality Control ◽  
Allelic Variation ◽  
Association Studies ◽  
Genetic Data ◽  
Genome Wide Association ◽  
Genome Wide Association Studies ◽  
Genotype Data ◽  
Uk Biobank ◽  
Genome Wide ◽  
Wide Range

AbstractThe UK Biobank project is a large prospective cohort study of ~500,000 individuals from across the United Kingdom, aged between 40-69 at recruitment. A rich variety of phenotypic and health-related information is available on each participant, making the resource unprecedented in its size and scope. Here we describe the genome-wide genotype data (~805,000 markers) collected on all individuals in the cohort and its quality control procedures. Genotype data on this scale offers novel opportunities for assessing quality issues, although the wide range of ancestries of the individuals in the cohort also creates particular challenges. We also conducted a set of analyses that reveal properties of the genetic data – such as population structure and relatedness – that can be important for downstream analyses. In addition, we phased and imputed genotypes into the dataset, using computationally efficient methods combined with the Haplotype Reference Consortium (HRC) and UK10K haplotype resource. This increases the number of testable variants by over 100-fold to ~96 million variants. We also imputed classical allelic variation at 11 human leukocyte antigen (HLA) genes, and as a quality control check of this imputation, we replicate signals of known associations between HLA alleles and many common diseases. We describe tools that allow efficient genome-wide association studies (GWAS) of multiple traits and fast phenome-wide association studies (PheWAS), which work together with a new compressed file format that has been used to distribute the dataset. As a further check of the genotyped and imputed datasets, we performed a test-case genome-wide association scan on a well-studied human trait, standing height.

scholarly journals Identifying Anti-Oxidant Biosynthesis Genes in Pearl Millet [Pennisetum glaucum (L.) R. Br.] Using Genome—Wide Association Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Chandra Bhan Yadav ◽  
Jayanti Tokas ◽  
Devvart Yadav ◽  
Ana Winters ◽  
Ram B. Singh ◽  
...  
Keyword(s):  
Pearl Millet ◽  
Pennisetum Glaucum ◽  
Association Studies ◽  
Genome Wide Association ◽  
Total Phenolic ◽  
Genome Wide Association Studies ◽  
Antioxidant Power ◽  
Genome Wide ◽  
Cereal Grain ◽  
Wide Range

Pearl millet [Pennisetum glaucum (L.) R Br.] is an important staple food crop in the semi-arid tropics of Asia and Africa. It is a cereal grain that has the prospect to be used as a substitute for wheat flour for celiac patients. It is an important antioxidant food resource present with a wide range of phenolic compounds that are good sources of natural antioxidants. The present study aimed to identify the total antioxidant content of pearl millet flour and apply it to evaluate the antioxidant activity of its 222 genotypes drawn randomly from the pearl millet inbred germplasm association panel (PMiGAP), a world diversity panel of this crop. The total phenolic content (TPC) significantly correlated with DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity (% inhibition), which ranged from 2.32 to 112.45% and ferric-reducing antioxidant power (FRAP) activity ranging from 21.68 to 179.66 (mg ascorbic acid eq./100 g). Genome-wide association studies (GWAS) were conducted using 222 diverse accessions and 67 K SNPs distributed across all the seven pearl millet chromosomes. Approximately, 218 SNPs were found to be strongly associated with DPPH and FRAP activity at high confidence [–log (p) > 3.0–7.4]. Furthermore, flanking regions of significantly associated SNPs were explored for candidate gene harvesting. This identified 18 candidate genes related to antioxidant pathway genes (flavanone 7-O-beta-glycosyltransferase, GDSL esterase/lipase, glutathione S-transferase) residing within or near the association signal that can be selected for further functional characterization. Patterns of genetic variability and the associated genes reported in this study are useful findings, which would need further validation before their utilization in molecular breeding for high antioxidant-containing pearl millet cultivars.

scholarly journals emeraLD: Rapid Linkage Disequilibrium Estimation with Massive Data Sets

2018 ◽  
Author(s):  
Corbin Quick ◽  
Christian Fuchsberger ◽  
Daniel Taliun ◽  
Gonçalo Abecasis ◽  
Michael Boehnke ◽  
...  
Keyword(s):  
Linkage Disequilibrium ◽  
Association Studies ◽  
Random Access ◽  
Supplementary Information ◽  
Data Sets ◽  
Genome Wide Association Studies ◽  
Summary Statistics ◽  
Genome Wide ◽  
Wide Range ◽  
Supplementary Material

AbstractSummaryEstimating linkage disequilibrium (LD) is essential for a wide range of summary statistics-based association methods for genome-wide association studies (GWAS). Large genetic data sets, e.g. the TOPMed WGS project and UK Biobank, enable more accurate and comprehensive LD estimates, but increase the computational burden of LD estimation. Here, we describe emeraLD (Efficient Methods for Estimation and Random Access of LD), a computational tool that leverages sparsity and haplotype structure to estimate LD orders of magnitude faster than existing tools.Availability and ImplementationemeraLD is implemented in C++, and is open source under GPLv3. Source code, documentation, an R interface, and utilities for analysis of summary statistics are freely available at http://github.com/statgen/[email protected] informationSupplementary data are available at Bioinformatics online.

scholarly journals Complex polymorphisms in endocytosis genes suggest alpha-cyclodextrin as a treatment for breast cancer

2017 ◽  
Author(s):  
Knut M. Wittkowski ◽  
Christina Dadurian ◽  
Martin P. Seybold ◽  
Han Sang Kim ◽  
Ayuko Hoshino ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Animal Studies ◽  
Association Studies ◽  
Treatment Options ◽  
Cell Cycle Control ◽  
Genome Wide Association Studies ◽  
Nucleotide Polymorphisms ◽  
Genome Wide ◽  
Estrogen Receptor Positive

AbstractMost breast cancer deaths are caused by metastasis and treatment options beyond radiation and cytotoxic drugs, which have severe side effects, and hormonal treatments, which are or become ineffective for many patients, are urgently needed. This study reanalyzed existing data from three genome-wide association studies (GWAS) using a novel computational biostatistics approach (muGWAS), which had been validated in studies of 600–2000 subjects in epilepsy and autism. MuGWAS jointly analyzes several neighboring single nucleotide polymorphisms while incorporating knowledge about genetics of heritable diseases into the statistical method and about GWAS into the rules for determining adaptive genome-wide significance.Results from three independent GWAS of 1000–2000 subjects each, which were made available under the National Institute of Health’s “Up For A Challenge” (U4C) project, not only confirmed cell-cycle control and receptor/AKT signaling, but, for the first time in breast cancer GWAS, also consistently identified many genes involved in endo-/exocytosis (EEC), most of which had already been observed in functional and expression studies of breast cancer. In particular, the findings include genes that translocate (ATP8A1, ATP8B1, ANO4, ABCA1) and metabolize (AGPAT3, AGPAT4, DGKQ, LPPR1) phospholipids entering the phosphatidylinositol cycle, which controls EEC. These novel findings suggest scavenging phospholipids via alpha-cyclodextrins (αCD) as a novel intervention to control local spread of cancer, packaging of exosomes (which prepare distant microenvironment for organ-specific metastases), and endocytosis of β1 integrins (which are required for spread of metastatic phenotype and mesenchymal migration of tumor cells).Beta-cyclodextrins (βCD) have already been shown to be effective inin vitroand animal studies of breast cancer, but exhibits cholesterol-related ototoxicity. The smaller αCDs also scavenges phospholipids, but cannot fit cholesterol. Anin-vitrostudy presented here confirms hydroxypropyl (HP)-αCD to be twice as effective as HPβCD against migration of human cells of both receptor negative and estrogen-receptor positive breast cancer.If the previous successful animal studies with βCDs are replicated with the safer and more effective αCDs, clinical trials of adjuvant treatment with αCDs are warranted. Ultimately, all breast cancer are expected to benefit from treatment with HPαCD, but women with triplenegative breast cancer (TNBC) will benefit most, because they have fewer treatment options and their cancer advances more aggressively.

scholarly journals Evidence for specificity of polygenic contributions to attainment in English, maths and science during adolescence

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Georgina Donati ◽  
Iroise Dumontheil ◽  
Oliver Pain ◽  
Kathryn Asbury ◽  
Emma L. Meaburn
Keyword(s):  
Association Studies ◽  
Genome Wide Association Studies ◽  
Genetic Associations ◽  
Parents And Children ◽  
Genome Wide ◽  
Wide Range ◽  
Gene Level ◽  
Significant Single Nucleotide Polymorphism ◽  
Genetic Contributions ◽  
Critical Developmental Period

AbstractHow well one does at school is predictive of a wide range of important cognitive, socioeconomic, and health outcomes. The last few years have shown marked advancement in our understanding of the genetic contributions to, and correlations with, academic attainment. However, there exists a gap in our understanding of the specificity of genetic associations with performance in academic subjects during adolescence, a critical developmental period. To address this, the Avon Longitudinal Study of Parents and Children was used to conduct genome-wide association studies of standardised national English (N = 5983), maths (N = 6017) and science (N = 6089) tests. High SNP-based heritabilities (h2SNP) for all subjects were found (41–53%). Further, h2SNP for maths and science remained after removing shared variance between subjects or IQ (N = 3197–5895). One genome-wide significant single nucleotide polymorphism (rs952964, p = 4.86 × 10–8) and four gene-level associations with science attainment (MEF2C, BRINP1, S100A1 and S100A13) were identified. Rs952964 remained significant after removing the variance shared between academic subjects. The findings highlight the benefits of using environmentally homogeneous samples for genetic analyses and indicate that finer-grained phenotyping will help build more specific biological models of variance in learning processes and abilities.

Sign in / Sign up

Export Citation Format

Share Document