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7 result(s) for "Raine, Emma V A"
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Increased type II deiodinase protein in OA-affected cartilage and allelic imbalance of OA risk polymorphism rs225014 at DIO2 in human OA joint tissues
Objective Genetic variation at the type II deiodinase (D2) gene (DIO2) was previously identified as osteoarthritis (OA) risk factor. To investigate mechanisms possibly underlying this association, we assessed D2 protein in healthy and OA-affected cartilage and investigated allelic balance of the OA risk polymorphism rs225014 at DIO2 in human OA joints. Methods Immunohistochemical staining of healthy and OA-affected cartilage was performed for D2. We then assessed allelic balance of DIO2 mRNA within OA-affected cartilage both at and away from the lesion, ligaments and subchondral bone. Allelic balance was measured by the amount of alleles ‘C’ and ‘T’ of the intragenic OA risk polymorphism rs225014 in heterozygous carriers. Results A markedly higher amount of D2 positive cells and staining intensity was observed in OA cartilage. A significant, 1.3-fold higher presence was observed for the OA-associated rs225014 ‘C’ allele relative to the ‘T’ allele of DIO2, which was significant in 28 of 31 donors. Conclusion In OA cartilage, D2 protein presence is increased. The allelic imbalance of the DIO2 mRNA transcript, with the OA risk allele ‘C’ of rs225014 more abundant than the wild-type ‘T’ allele in heterozygote carriers provides a possible mechanism by which genetic variation at DIO2 confers OA risk.
Allelic expression analysis of the osteoarthritis susceptibility locus that maps to chromosome 3p21 reveals cis-acting eQTLs at GNL3 and SPCS1
Background An osteoarthritis (OA) susceptibility locus has been mapped to chromosome 3p21, to a region of high linkage disequilibrium encompassing twelve genes. Six of these genes are expressed in joint tissues and we therefore assessed whether any of the six were subject to cis -acting regulatory polymorphisms active in these tissues and which could therefore account for the association signal. Methods We measured allelic expression using pyrosequencing assays that can distinguish mRNA output from each allele of a transcript single nucleotide polymorphism. We assessed RNA extracted from the cartilage and other joint tissues of OA patients who had undergone elective joint replacement surgery. A two-tailed Mann–Whitney exact test was used to test the significance of any allelic differences. Results GNL3 and SPCS1 demonstrated significant allelic expression imbalance (AEI) in OA cartilage ( GNL3 , mean AEI = 1.04, p  = 0.0002; SPCS1 , mean AEI = 1.07, p  < 0.0001). Similar results were observed in other tissues. Expression of the OA-associated allele was lower than that of the non-associated allele for both genes. Conclusions cis -acting regulatory polymorphisms acting on GNL3 and SPCS1 contribute to the OA association signal at chromosome 3p21, and these genes therefore merit further investigation.
Allelic expression analysis of the osteoarthritis susceptibility locus that maps to MICAL3
Background A genome-wide association scan with subsequent replication study that involved over 67,000 individuals of European ancestry has produced evidence of association of single nucleotide polymorphism rs2277831 to primary osteoarthritis (OA) with a P-value of 2.9 × 10 -5 . rs2277831, an A/G transition, is located in an intron of MICAL3 . This gene is located on chromosome 22q11.21 and the association signal encompasses two additional genes, BCL2L13 and BID . It is becoming increasingly apparent that many common complex traits are mediated by cis -acting regulatory polymorphisms that influence, in a tissue-specific manner, gene expression or transcript stability. Methods We used total and allelic expression analysis to assess whether the OA association to rs2277831 is mediated by an influence on MICAL3, BCL2L13 or BID expression. Using RNA extracted from joint tissues of 60 patients who had undergone elective joint replacement surgery, we assessed whether rs2277831 correlated with allelic expression of either of the three genes by: 1) measuring the expression of each gene by quantitative PCR and then stratifying the data by genotype at rs2277831 and 2) accurately discriminating and quantifying the mRNA synthesised from the alleles of OA patients using allelic-quantitative PCR. Results We found no evidence for a correlation between gene expression and genotype at rs2277831, with P-values of 0.09 for BCL2L13 , 0.07 for BID and 0.33 for MICAL3 . In the allelic expression analysis we observed several examples of significant (p < 0.05) allelic imbalances, with an allelic expression ratio of 2.82 observed in BCL2L13 (P = 0.004), 2.09 at BID (P = 0.001) and the most extreme case being at MICAL3 , with an allelic expression ratio of 5.47 (P = 0.001). However, there was no correlation observed between the pattern of allelic expression and the genotype at rs2277831. Conclusions In the tissues that we have studied, our data do not support our hypothesis that the association between rs2277831 and OA is due to the effect this SNP has on MICAL3, BCL2L13 or BID gene expression. Instead, our data point towards other functional effects accounting for the OA associated signal.
Allelic expression analysis of the osteoarthritis susceptibility gene COL11A1 in human joint tissues
Background The single nucleotide polymorphism (SNP) rs2615977 is associated with osteoarthritis (OA) and is located in intron 31 of COL11A1 , a strong candidate gene for this degenerative musculoskeletal disease. Furthermore, the common non-synonymous COL11A1 SNP rs1676486 is associated with another degenerative musculoskeletal disease, lumbar disc herniation (LDH). rs1676486 is a C-T transition mediating its affect on LDH susceptibility by modulating COL11A1 expression. The risk T-allele of rs1676486 leads to reduced expression of the COL11A1 transcript, a phenomenon known as allelic expression imbalance (AEI). We were keen therefore to assess whether the effect that rs1676486 has on COL11A1 expression in LDH is also observed in OA and whether the rs2615977 association to OA also marked AEI. Methods Using RNA from OA cartilage, we assessed whether either SNP correlated with COL11A1 AEI by 1) measuring COL11A1 expression and stratifying the data by genotype at each SNP; and 2) quantifying the mRNA transcribed from each allele of the two SNPs. We also assessed whether rs1676486 was associated with OA susceptibility using a case–control cohort of over 18,000 individuals. Results We observed significant AEI at rs1676486 (p < 0.0001) with the T-allele correlating with reduced COL11A1 expression. This corresponded with observations in LDH but the SNP was not associated with OA. We did not observe AEI at rs2615977. Conclusions COL11A1 is subject to AEI in OA cartilage. AEI at rs1676486 is a risk factor for LDH, but not for OA. These two diseases therefore share a common functional phenotype, namely AEI of COL11A1 , but this appears to be a disease risk only in LDH. Other functional effects on COL11A1 presumably account for the OA susceptibility that maps to this gene.
Identification of new susceptibility loci for osteoarthritis (arcOGEN): a genome-wide association study
Osteoarthritis is the most common form of arthritis worldwide and is a major cause of pain and disability in elderly people. The health economic burden of osteoarthritis is increasing commensurate with obesity prevalence and longevity. Osteoarthritis has a strong genetic component but the success of previous genetic studies has been restricted due to insufficient sample sizes and phenotype heterogeneity. We undertook a large genome-wide association study (GWAS) in 7410 unrelated and retrospectively and prospectively selected patients with severe osteoarthritis in the arcOGEN study, 80% of whom had undergone total joint replacement, and 11 009 unrelated controls from the UK. We replicated the most promising signals in an independent set of up to 7473 cases and 42 938 controls, from studies in Iceland, Estonia, the Netherlands, and the UK. All patients and controls were of European descent. We identified five genome-wide significant loci (binomial test p≤5·0×10−8) for association with osteoarthritis and three loci just below this threshold. The strongest association was on chromosome 3 with rs6976 (odds ratio 1·12 [95% CI 1·08–1·16]; p=7·24×10−11), which is in perfect linkage disequilibrium with rs11177. This SNP encodes a missense polymorphism within the nucleostemin-encoding gene GNL3. Levels of nucleostemin were raised in chondrocytes from patients with osteoarthritis in functional studies. Other significant loci were on chromosome 9 close to ASTN2, chromosome 6 between FILIP1 and SENP6, chromosome 12 close to KLHDC5 and PTHLH, and in another region of chromosome 12 close to CHST11. One of the signals close to genome-wide significance was within the FTO gene, which is involved in regulation of bodyweight—a strong risk factor for osteoarthritis. All risk variants were common in frequency and exerted small effects. Our findings provide insight into the genetics of arthritis and identify new pathways that might be amenable to future therapeutic intervention. arcOGEN was funded by a special purpose grant from Arthritis Research UK.
Mutations in HYAL2, Encoding Hyaluronidase 2, Cause a Syndrome of Orofacial Clefting and Cor Triatriatum Sinister in Humans and Mice
Orofacial clefting is amongst the most common of birth defects, with both genetic and environmental components. Although numerous studies have been undertaken to investigate the complexities of the genetic etiology of this heterogeneous condition, this factor remains incompletely understood. Here, we describe mutations in the HYAL2 gene as a cause of syndromic orofacial clefting. HYAL2, encoding hyaluronidase 2, degrades extracellular hyaluronan, a critical component of the developing heart and palatal shelf matrix. Transfection assays demonstrated that the gene mutations destabilize the molecule, dramatically reducing HYAL2 protein levels. Consistent with the clinical presentation in affected individuals, investigations of Hyal2-/- mice revealed craniofacial abnormalities, including submucosal cleft palate. In addition, cor triatriatum sinister and hearing loss, identified in a proportion of Hyal2-/- mice, were also found as incompletely penetrant features in affected humans. Taken together our findings identify a new genetic cause of orofacial clefting in humans and mice, and define the first molecular cause of human cor triatriatum sinister, illustrating the fundamental importance of HYAL2 and hyaluronan turnover for normal human and mouse development.
Migration and Evolution of giant ExoPlanets (MEEP) I: Nine Newly Confirmed Hot Jupiters from the TESS Mission
Hot Jupiters were many of the first exoplanets discovered in the 1990s, but in the decades since their discovery, the mysteries surrounding their origins remain. Here, we present nine new hot Jupiters (TOI-1855 b, TOI-2107 b, TOI-2368 b, TOI-3321 b, TOI-3894 b, TOI-3919 b, TOI-4153 b, TOI-5232 b, and TOI-5301 b) discovered by NASA's TESS mission and confirmed using ground-based imaging and spectroscopy. These discoveries are the first in a series of papers named the Migration and Evolution of giant ExoPlanets (MEEP) survey and are part of an ongoing effort to build a complete sample of hot Jupiters orbiting FGK stars, with a limiting Gaia \\(G\\)-band magnitude of 12.5. This effort aims to use homogeneous detection and analysis techniques to generate a set of precisely measured stellar and planetary properties that is ripe for statistical analysis. The nine planets presented in this work occupy a range of masses (0.55 Jupiter masses (M\\(_{\\rm{J}}\\)) \\(<\\) M\\(_{\\rm{P}}\\) \\(<\\) 3.88 M\\(_{\\rm{J}}\\)) and sizes (0.967 Jupiter radii (R\\(_{\\rm{J}}\\)) \\(<\\) R\\(_{\\rm{P}}\\) \\(<\\) 1.438 R\\(_{\\rm{J}}\\)) and orbit stars that range in temperature from 5360 K \\(<\\) Teff \\(<\\) 6860 K with Gaia \\(G\\)-band magnitudes ranging from 11.1 to 12.7. Two of the planets in our sample have detectable orbital eccentricity: TOI-3919 b (\\(e = 0.259^{+0.033}_{-0.036}\\)) and TOI-5301 b (\\(e = 0.33^{+0.11}_{-0.10}\\)). These eccentric planets join a growing sample of eccentric hot Jupiters that are consistent with high-eccentricity tidal migration, one of the three most prominent theories explaining hot Jupiter formation and evolution.