20 research outputs found
Genome-wide association study identifies variants in the MHC class I, IL10, and IL23R-IL12RB2 regions associated with Behcet's disease
Behcet's disease is a genetically complex disease of unknown etiology characterized by recurrent inflammatory attacks affecting the orogenital mucosa, eyes and skin. We performed a genome-wide association study with 311,459 SNPs in 1,215 individuals with Behcet's disease (cases) and 1,278 healthy controls from Turkey. We confirmed the known association of Behcet's disease with HLA-B*51 and identified a second, independent association within the MHC Class I region. We also identified an association at IL10 (rs1518111, P = 1.88 x 10(-8)). Using a meta-analysis with an additional five cohorts from Turkey, the Middle East, Europe and Asia, comprising a total of 2,430 cases and 2,660 controls, we identified associations at IL10 (rs1518111, P = 3.54 x 10(-18), odds ratio = 1.45, 95% CI 1.34-1.58) and the IL23R-IL12RB2 locus (rs924080, P = 6.69 x 10(-9), OR = 1.28, 95% CI 1.18-1.39). The disease-associated IL10 variant (the rs1518111 A allele) was associated with diminished mRNA expression and low protein production
Kinetic effects of myosin regulatory light chain phosphorylation on skeletal muscle contraction.
Kinetic analysis of contracting fast and slow rabbit muscle fibers in the presence of the tension inhibitor 2,3-butanedione monoxime suggests that regulatory light chain (RLC) phosphorylation up-regulates the flux of weakly attached cross-bridges entering the contractile cycle by increasing the actin-catalyzed release of phosphate from myosin. This step appears to be separate from earlier Ca(2+) regulated steps. Small step-stretches of single skinned fibers were used to study the effect of phosphorylation on fiber mechanics. Subdivision of the resultant tension transients into the Huxley-Simmons phases 1, 2(fast), 2(slow), 3, and 4 reveals that phosphorylation reduces the normalized amplitude of the delayed rise in tension (stretch activation response) by decreasing the amplitudes of phase 3 and, to a lesser extent, phase 2(slow). In slow fibers, the RLC P1 isoform phosphorylates at least 4-fold faster than the P2 isoform, complicating the role of RLC phosphorylation in heart and slow muscle. We discuss the functional relevance of the regulation of stretch activation by RLC phosphorylation for cardiac and other oscillating muscles and speculate how the interaction of the two heads of myosin could account for the inverse effect of Ca(2+) levels on isometric tension and rate of force redevelopment (k(TR))
Characterization of immunoglobulin mutations in humans with activation-induced cytidine deaminase deficiency
The Overall Pattern of Cardiac Contraction Depends on a Spatial Gradient of Myosin Regulatory Light Chain Phosphorylation
AbstractEvolution of the human heart has incorporated a variety of successful strategies for motion used throughout the animal kingdom. One such strategy is to add the efficiency of torsion to compression so that blood is wrung, as well as pumped, out of the heart. Models of cardiac torsion have assumed uniform contractile properties of muscle fibers throughout the heart. Here, we show how a spatial gradient of myosin light chain phosphorylation across the heart facilitates torsion by inversely altering tension production and the stretch activation response. To demonstrate the importance of cardiac light chain phosphorylation, we cloned a myosin light chain kinase from a human heart and have identified a gain-in-function mutation in two individuals with cardiac hypertrophy
Genome-Wide Analysis of Imputed Genotypes Identifies Chemokine Receptor-1 CCR1) As a Novel Candidate Risk Locus in Behcet's Disease.
High Density Genotyping Of Immune-Related Disease Genes Identifies 7 New Susceptibility Loci For Behcets Disease
Genome-Wide Analysis Reveals a Recessive Association of ERAP1 Variants with Behcet's Disease and Epistasis Between ERAP1 and HLA-B*51.
Major Histocompatibility Complex Class II Gene Cluster Harbors Systemic Juvenile Idiopathic Arthritis Susceptibility Locus
Genome-wide association analysis identifies new susceptibility loci for Behcet's disease and epistasis between HLA-B*51 and ERAP1
Individuals with Behcet's disease suffer from episodic inflammation often affecting the orogenital mucosa, skin and eyes. To discover new susceptibility loci for Behcet's disease, we performed a genome-wide association study (GWAS) of 779,465 SNPs with imputed genotypes in 1,209 Turkish individuals with Behcet's disease and 1,278 controls. We identified new associations at CCR1, STAT4 and KLRC4. Additionally, two SNPs in ERAP1, encoding ERAP1 p.Asp575Asn and p.Arg725Gln alterations, recessively conferred disease risk. These findings were replicated in 1,468 independent Turkish and/or 1,352 Japanese samples (combined meta-analysis P < 2 x 10(-9)). We also found evidence for interaction between HLA-B*51 and ERAP1 (P = 9 x 10(-4)). The CCR1 and STAT4 variants were associated with gene expression differences. Three risk loci shared with ankylosing spondylitis and psoriasis (the MHC class I region, ERAP1 and IL23R and the MHC class I-ERAP1 interaction), as well as two loci shared with inflammatory bowel disease (IL23R and IL10) implicate shared pathogenic pathways in the spondyloarthritides and Behcet's disease