BACKGROUND:Irritable bowel syndrome (IBS) is a complex disorder of gut-brain interaction, with heterogeneous symptoms, no available biomarkers and limited pathogenetic insight. OBJECTIVE:To identify genetic risk factors and actionable mechanisms for future clinical translation in IBS. DESIGN:We conducted a genome-wide association study (GWAS) meta-analysis of IBS in 2 775 539 individuals from 22 biobanks. IBS genetics was studied across multiple ancestries, different case definitions and symptom-related subtypes. Heritability and genetic correlations with other traits were estimated, and Mendelian randomisation was used to test causal relationships. GWAS data were functionally annotated and fine-mapped to prioritise tissues, cell types, pathways, candidate genes, specific mechanisms and druggable targets. RESULTS:Significant heritability was only detected in individuals of European ancestry, with near-identical genetic architecture across case definitions. Genetic correlations with GI, psychiatric and cardiometabolic traits were observed, including causal relationships with triglyceride (TG) levels. Functional annotation of IBS risk loci highlighted cell types and pathways relevant to brain, enteric neuro-glial and cardiometabolic domains, as well as actionable targets like GCKR, a regulator of TG metabolism. Druggability analyses converged on cardiometabolic mechanisms, including TG modulation. IBS polygenic risk scores were derived and showed a significant association with case status in an independent case-control dataset, supporting further evaluation in external population-based and clinically ascertained cohorts. CONCLUSIONS:This study provides the most comprehensive assessment of IBS genetics to date, demonstrating reproducible polygenic inheritance. We link IBS risk to convergent neurogastrointestinal and novel cardiometabolic mechanisms, highlight specific biological pathways and actionable mechanisms and outline translational opportunities emerging from integrated computational analyses.

Thyroid diseases are common and highly heritable. We performed a meta-analysis of genome-wide association studies from 19 biobanks for five thyroid diseases: thyroid cancer (ThC), benign nodular goiter, Graves’ disease, lymphocytic thyroiditis and primary hypothyroidism. We analyzed genetic association data from ~2.9 million genomes and identified 313 known and 570 new independent loci linked to thyroid diseases. We discovered genetic correlations between ThC, benign nodular goiter and autoimmune thyroid diseases ( rg = 0.16–0.97). Telomere maintenance genes contributed to benign and malignant thyroid nodular disease risk, whereas cell cycle, DNA repair and damage response genes were associated with ThC. We propose a paradigm that explains genetic predisposition to benign and malignant thyroid nodules. We found polygenic risk score associations with ThC risk of structural disease recurrence, tumor size, multifocality, lymph node metastases and extranodal extension. Polygenic risk scores identified individuals with aggressive ThC in a biobank, creating an opportunity for genetically informed population screening.

Background:In ∼10% of asthma patients, symptoms remain uncontrolled despite maximal treatment, representing an unmet clinical need. The causal variants, genes and pathways underlying genetic risk factors have not been fully elucidated, and it is unclear whether there are unique genetic risk factors for this asthma subtype. Methods:We used electronic healthcare records linked to UK Biobank to identify asthma patients with high treatment burden and/or worse outcomes. We performed a genome-wide association study (GWAS) with this case population and healthy controls. We sought replication for associated (p≤5×10-6) signals in four independent studies (12 152 cases and 32 316 controls). Replicated signals were fine-mapped and linked to genes and pathways. Results:In total, 7681 participants met our case definition and showed enrichment for adult-onset asthma, female gender and higher body mass index compared to asthma individuals not meeting case criteria. GWAS with 7681 cases and 38 405 controls revealed 21 reproducible association signals that had previously been associated with asthma, but had a larger effect size in our study. Variant-to-gene mapping highlighted 85 candidate genes, five of which were considered high confidence (BACH2, D2HGDH, IL1RL1, RPS26, SMAD3). Conclusion:We present the first use of electronic healthcare records in UK Biobank to identify a subtype of asthma enriched for patients with high treatment burden and/or worse outcomes. Our findings support the role of known asthma genes, highlighting genetic risk variants with stronger effect in these groups of patients. The prioritised genes provide potential therapeutic opportunities for this difficult-to-treat patient population.

Itaconate is an immunomodulatory metabolite that alters mitochondrial metabolism and immune cell function. This organic acid is endogenously synthesized by tricarboxylic acid (TCA) metabolism downstream of TLR signalling. Itaconate-based treatment strategies are under investigation to mitigate numerous inflammatory conditions. However, little is known about the turnover rate of itaconate in circulation, the kinetics of its degradation and the broader consequences on metabolism. By combining mass spectrometry and in vivo 13C itaconate tracing in male mice, we demonstrate that itaconate is rapidly eliminated from plasma, excreted via urine and fuels TCA cycle metabolism specifically in the liver and kidneys. Our results further reveal that itaconate is converted into acetyl-CoA, mesaconate and citramalate. Itaconate administration also influences branched-chain amino acid metabolism and succinate levels, indicating a functional impact on succinate dehydrogenase and methylmalonyl-CoA mutase activity in male rats and mice. Our findings uncover a previously unknown aspect of itaconate metabolism, highlighting its rapid catabolism in vivo that contrasts findings in cultured cells.

Neuropathic pain is a common and debilitating symptom with limited treatment options. Genetic studies, which can provide vital evidence for drug development, have identified only 3 genome-wide significant signals for neuropathic pain traits. To address this, we performed the largest genome-wide association study (GWAS) to date of all-cause neuropathic pain and neuropathic pain subtypes. We defined all-cause neuropathic pain and 33 neuropathic pain subtypes using DeepPheWAS software in the UK Biobank, taking advantage of the longitudinal drug prescription data alongside clinical and self-reported records. We performed a GWAS of all-cause neuropathic pain (33,278 cases, 140,134 controls) as our primary analysis and GWASs of neuropathic pain subtypes as secondary analyses. We used 8 variant-to-gene criteria to identify putative causal genes. We identified 7 independent novel genome-wide associations for neuropathic pain phenotypes, which mapped to 22 novel putative causal genes. NCAM1 was the only gene identified from the primary analysis of all-cause neuropathic pain and met the most variant-to-gene criteria (4) of any identified gene. Of the 21 other genes, ASCC1, CHST3, C4A/C4B, and KCNN2 had the most compelling evidence for mechanistic involvement in neuropathic pain. We have performed the largest GWAS to date of all-cause neuropathic pain and more than doubled the number of genome-wide significant associations for neuropathic pain traits, identifying putative causal genes. There is strong evidence for the involvement of NCAM1 in neuropathic pain, which merits for further study for drug development.

Thyroid diseases are common and highly heritable. Under the Global Biobank Meta-analysis Initiative, we performed a meta-analysis of genome-wide association studies from 19 biobanks for five thyroid diseases: thyroid cancer, benign nodular goiter, Graves' disease, lymphocytic thyroiditis, and primary hypothyroidism. We analyzed genetic association data from ~2.9 million genomes and identified 235 known and 501 novel independent variants significantly linked to thyroid diseases. We discovered genetic correlations between thyroid cancer, benign nodular goiter, and autoimmune thyroid diseases (r 2 =0.21-0.97). Telomere maintenance genes contribute to benign and malignant thyroid nodular disease risk, whereas cell cycle, DNA repair, and DNA damage response genes are predominantly associated with thyroid cancer. We proposed a paradigm explaining genetic predisposition to benign and malignant thyroid nodules. We evaluated thyroid cancer polygenic risk scores (PRS) for clinical applications in thyroid cancer diagnosis. We found PRS associations with thyroid cancer risk features: multifocality, lymph node metastases, and extranodal extension.

Background:Specialist intervention in COPD is often reactive, resulting in inequalities in the provision of care. A proactive approach, in which individuals with modifiable disease are identified from primary care records, may help to tackle this inequality in access. Aim:To estimate the prevalence of "treatable traits" in COPD in a primary care research database and to assess health service usage. Methods:We performed a secondary analysis of individuals with either 1) a primary care diagnosis of COPD or 2) obstructive spirometry and history of ever smoking in a large observational study recruiting individuals aged 40-69 years old in Leicestershire, UK. Spirometry, height, weight and smoking history were collected prospectively and linked to individuals' primary care records. "Treatable traits" were identified from primary care records (frequent exacerbations, current smoking, low body mass index, respiratory failure, severe breathlessness, potential suitability for lung volume reduction or psychological comorbidity). Differences in demographics and health usage between those with and without "treatable traits" were assessed. Results:In total, of the 347 individuals with COPD, 186 had at least one "treatable trait". Compared to those without treatable traits, individuals with treatable traits were younger (61 vs 64 years, p<0.001), had more severe airflow obstruction (FEV1 86% vs 94% predicted, p=0.002), higher eosinophil count (0.32 vs 0.27 cells/μL, p=0.04) and were more socioeconomically deprived (UK Indices of Multiple Deprivation decile 4.3 vs 5.8, p<0.001). Individuals with treatable traits had a higher annual primary care health usage (47 vs 30 visits per year, p=0.001). Referrals rates to specialist respiratory services were low in both groups. Conclusion:Treatable traits are common in COPD and can be identified from routinely collected primary care data. Treatable traits are associated with younger age and greater deprivation. These individuals pose a significant burden to primary care yet are rarely referred to specialist respiratory services.

RATIONALE Lung function predicts mortality and is a diagnostic criterion for COPD. Identification of causal genes and the variants and pathways that impact gene function and regulation can inform therapeutic interventions for COPD. Genome-wide association studies (GWAS) of imputed genotypes discovered 1,020 mostly common genetic variants associated with lung function. Whole-exome sequencing (WES) is better suited to study rarer protein-coding variants that may not be well imputed. We analysed the UK Biobank WES data to identify putative causal genes for lung function, not yet detected by GWAS, and to fine map the architecture of causal variants within genes. METHODS We included 343,104 European UK Biobank samples with WES data and four quantitative lung function phenotypes: FEV1, FVC, FEV1/FVC and peak expiratory flow (PEF). We performed single variant tests of 6.7 million variants with minor allele frequency (MAF) <1% and gene-based collapsing tests to enhance power to detect rare variant effects in aggregate. For gene-based tests models were run using MAF filters of <1%, <0.1%, <0.01%, <0.001% and singletons, and 2 variant function criteria: (i) predicted loss-of-function (pLoF); (ii) pLoF + deleterious missense. Qualifying variants were tested in aggregate for 18,468 genes using burden testing and methods accommodating opposing effect directions. RESULTSHMCN1 (Hemicentin-1), previously implicated by a common (MAF 24%) intronic variant, harboured a novel rare (MAF 0.03%) missense variant associated with FEV1/FVC (P=4.78×10-9) and was highly significant in gene-based testing (P=3.27×10-51) with a burden of over 900 pLoF and missense variants of MAF<0.01% contributing. This was notable amongst the other 17 genes with a significant gene-based result (P<2.69×10-6; Bonferroni correction for genes tested), with the next most significant result for LRP1 (P=6.73×10-15) driven by only 2 variants. In total rare variant testing implicated 28 genes, 8 of which have not been previously reported in GWAS. CONCLUSION We discover novel genes associated with lung function and highlight novel variants at known genes. In particular, we show allelic series for lung function – that is, statistically independent genetic variants that each implicate the same gene and show dose-response effects on lung function, such as the common, rare and very rare variants independently implicating HMCN1. Allelic series provide strong evidence to inform functional genomic studies and drug discovery.

The widespread adoption of high-calorie, high-fat, high-sucrose diets (HFHSD) has become a global health concern, particularly due to their association with cardiovascular diseases and metabolic disorders. These comorbidities increase susceptibility to severe outcomes from viral infections and trauma, with trauma-related incidents significantly contributing to global mortality rates. This context underscores the critical need for a reliable blood supply. Recent research has focused on high molecular weight (MW) polymerized human hemoglobin (PolyhHb) as a promising alternative to red blood cells (RBCs), showing encouraging outcomes in previous studies. Given the overlap of metabolic disorders and trauma-related health issues, it is crucial to assess the potential toxicity of PolyhHb transfusions, particularly in models that represent these vulnerable populations. This study evaluated the effects of PolyhHb exchange transfusion in guinea pigs that had developed metabolic disorders due to a 12-week HFHSD regimen. The guinea pigs, underwent a 20 % blood volume exchange transfusion with either PolyhHb or the lower molecular weight polymerized bovine hemoglobin, Oxyglobin. Results revealed that both PolyhHb and Oxyglobin transfusions led to liver damage, with a more pronounced effect observed in HFHSD-fed animals. Additionally, markers of cardiac dysfunction indicated signs of cardiac injury in both the HFHSD and normal diet groups following the Oxyglobin transfusion. This study highlights how pre-existing metabolic disorders can exacerbate the potential side effects of hemoglobin-based oxygen carriers (HBOCs). Importantly, the newer generation of high MW PolyhHb showed lower cardiac toxicity compared to the earlier generation low MW PolyhHb, known as Oxyglobin, even in models with pre-existing endothelial and metabolic challenges.

BACKGROUND:Preserved ratio impaired spirometry (PRISm) is defined as a forced expiratory volume in 1 s (FEV1) <80% predicted and FEV1/forced vital capacity ≥0.70. PRISm is associated with respiratory symptoms and comorbidities. Our objective was to discover novel genetic signals for PRISm and see if they provide insight into the pathogenesis of PRISm and associated comorbidities. METHODS:We undertook a genome-wide association study (GWAS) of PRISm in UK Biobank participants (Stage 1), and selected single nucleotide polymorphisms (SNPs) reaching genome-wide significance for replication in 13 cohorts (Stage 2). A combined meta-analysis of Stage 1 and Stage 2 was done to determine top SNPs. We used cross-trait linkage disequilibrium score regression to estimate genome-wide genetic correlation between PRISm and pulmonary and extrapulmonary traits. Phenome-wide association studies of top SNPs were performed. RESULTS:22 signals reached significance in the joint meta-analysis, including four signals novel for lung function. A strong genome-wide genetic correlation (rg) between PRISm and spirometric COPD (rg=0.62, p<0.001) was observed, and genetic correlation with type 2 diabetes (rg=0.12, p=0.007). Phenome-wide association studies showed that 18 of 22 signals were associated with diabetic traits and seven with blood pressure traits. CONCLUSION:This is the first GWAS to successfully identify SNPs associated with PRISm. Four of the signals, rs7652391 (nearest gene MECOM), rs9431040 (HLX), rs62018863 (TMEM114) and rs185937162 (HLA-B), have not been described in association with lung function before, demonstrating the utility of using different lung function phenotypes in GWAS. Genetic factors associated with PRISm are strongly correlated with risk of both other lung diseases and extrapulmonary comorbidity.

Introduction: Mutations in the PRKAG2 gene cause a complex myocardial disorder characterized by hypertrophic cardiomyopathy (HCM) and conduction disturbances. While prior studies associated PRKAG2 -linked hypertrophy with increased glycogen storage, many HCM phenotypes in the disorder remain unexplained by this effect alone. We aimed to uncover the molecular mechanisms by which PRKAG2 mutations induce myocyte hypertrophy and electrical changes during cardiac development. Methods: We created transgenic zebrafish expressing WT (Tg WT ) and pathological mutant (Tg R299Q ) murine Prkag2 cDNA under a myocardium-specific promoter. Using these models, we studied the impact of Prkag2 variant on myocyte electrical activity, metabolism, and cytoarchitecture across cardiogenesis and in mature hearts. Results: Tg R299Q adult fish showed hypertrophic cardiomyocytes, swollen mitochondria, and shortened sarcomere length compared to Tg WT and WT, mirroring human HCM phenotypes. The glycogen content was elevated in adult hearts but not during early cardiogenesis. Despite the absence of glycogen accumulation at 6-day post fertilization, Tg R299Q hearts showed electrical abnormalities, including a reduced conduction velocity, decreased Ca 2+ amplitude, and prolonged action potential durations in both atria and ventricles, compared to Tg WT and WT. Co-immunoprecipitation and proximity ligation assay revealed physical interactions between Prkag2 and myosin heavy chain (MYH), with the R299Q variant enhancing this interaction and altering the subcellular localization of Prkag2 from mitochondria to sarcomeres. Knockdown of the fish homolog of MYH7 ( vmhcl ) restored the early electrical disturbances caused by Tg R299Q . This abnormal MYH-Prkag2 interaction disturbed mitochondria and sarcomere organization contributing to altered myocyte cytoarchitecture observed in Tg R299Q . Conclusions: Mutant PRKAG2 altered cardiac excitability and Ca 2+ handling during embryogenesis, preceding glycogen accumulation. Enhanced binding between Prkag2 and MYHs contributed to these early changes. Our study revealed a novel link between sarcomere proteins and metabolic regulators in cardiac hypertrophy, suggesting a new therapeutic avenue for treating HCM.

Thyroid hormones play a critical role in regulation of multiple physiological functions and thyroid dysfunction is associated with substantial morbidity. Here, we use electronic health records to undertake a genome-wide association study of thyroid-stimulating hormone (TSH) levels, with a total sample size of 247,107. We identify 158 novel genetic associations, more than doubling the number of known associations with TSH, and implicate 112 putative causal genes, of which 76 are not previously implicated. A polygenic score for TSH is associated with TSH levels in African, South Asian, East Asian, Middle Eastern and admixed American ancestries, and associated with hypothyroidism and other thyroid disease in South Asians. In Europeans, the TSH polygenic score is associated with thyroid disease, including thyroid cancer and age-of-onset of hypothyroidism and hyperthyroidism. We develop pathway-specific genetic risk scores for TSH levels and use these in phenome-wide association studies to identify potential consequences of pathway perturbation. Together, these findings demonstrate the potential utility of genetic associations to inform future therapeutics and risk prediction for thyroid diseases.

Direct measurement of cardiac pressure-volume (PV) relationships is the gold standard for assessment of ventricular hemodynamics, but few innovations have been made to "multi-beat" PV analysis beyond traditional signal processing. The Prony method solves the signal recovery problem with a series of dampened exponentials or sinusoids. It achieves this by extracting the amplitude, frequency, dampening, and phase of each component. Since its inception, application of the Prony method to biologic and medical signal has demonstrated a relative degree of success, as a series of dampened complex sinusoids easily generalizes to multifaceted physiological processes. In cardiovascular physiology, the Prony analysis has been used to determine fatal arrythmia from electrocardiogram signals. However, application of the Prony method to simple left ventricular function based on pressure and volume analysis is absent. We have developed a new pipeline for analysis of pressure volume signals recorded from the left ventricle. We propose fitting pressure-volume data from cardiac catheterization to the Prony method for pole extraction and quantification of the transfer function. We implemented the Prony algorithm using open-source Python packages and analyzed the pressure and volume signals before and after severe hemorrhagic shock, and after resuscitation with stored blood. Each animal (n = 6 per group) underwent a 50% hemorrhage to induce hypovolemic shock, which was maintained for 30 min, and resuscitated with 3-week-old stored RBCs until 90% baseline blood pressure was achieved. Pressure-volume catheterization data used for Prony analysis were 1 s in length, sampled at 1000 Hz, and acquired at the time of hypovolemic shock, 15 and 30 min after induction of hypovolemic shock, and 10, 30, and 60 min after volume resuscitation. We next assessed the complex poles from both pressure and volume waveforms. To quantify deviation from the unit circle, which represents deviation from a Fourier series, we counted the number of poles at least 0.2 radial units away from it. We found a significant decrease in the number of poles after shock (p = 0.0072 vs. baseline) and after resuscitation (p = 0.0091 vs. baseline). No differences were observed in this metric pre and post volume resuscitation (p = 0.2956). We next found a composite transfer function using the Prony fits between the pressure and volume waveforms and found differences in both the magnitude and phase Bode plots at baseline, during shock, and after resuscitation. In summary, our implementation of the Prony analysis shows meaningful physiologic differences after shock and resuscitation and allows for future applications to broader physiological and pathophysiological conditions.

Cerebral malaria (CM) is a severe manifestation of malaria that commonly occurs in children and is hallmarked by neurologic symptoms and significant Plasmodium falciparum parasitemia. It is currently hypothesized that cerebral hypoperfusion from impaired microvascular oxygen transport secondary to parasitic occlusion of the microvasculature is responsible for cerebral ischemia and thus disease severity. Animal models to study CM, are known as experimental cerebral malaria (ECM), and include the C57BL/6J infected with Plasmodium berghei ANKA (PbA), which is ECM-susceptible, and BALB/c infected with PbA, which is ECM-resistant. Here we sought to investigate whether changes in oxygen (O2) delivery, O2 flux, and O2 utilization are altered in both these models of ECM using phosphorescence quenching microscopy (PQM) and direct measurement of microvascular hemodynamics using the cranial window preparation. Animal groups used for investigation consisted of ECM-susceptible C57BL/6 (Infected, n = 14) and ECM-resistant BALB/c (Infected, n = 9) mice. Uninfected C57BL/6 (n = 6) and BALB/c (n = 6) mice were included as uninfected controls. Control animals were manipulated in the exact same way as the infected mice (except for the infection itself). C57BL/6 ECM animals at day 6 of infection were divided into two cohorts: Early-stage ECM, presenting mild to moderate drops in body temperature (>34 < 36 °C) and Late-stage ECM, showing marked drops in body temperature (<33 °C). Data taken from new experiments conducted with these animal models were analyzed using a general linear mixed model. We constructed three general linear mixed models, one for total O2 content, another for total O2 delivery, and the third for total O2 content as a function of convective flow. We found that in both the ECM-susceptible C57BL/6J model and ECM-resistant BALB/c model of CM, convective and diffusive O2 flux along with pial hemodynamics are impaired. We further show that concomitant changes in p50 (oxygen partial pressure for 50% hemoglobin saturation), only 5 mmHg in the case of late-stage CM C57BL/6J mice, and O2 diffusion result in insufficient O2 transport by the pial microcirculation, and that both these changes are required for late-stage disease. In summary, we found impaired O2 transport and O2 affinity in late-stage ECM, but only the former in either early-stage ECM and ECM-resistant strains.

Lung-function impairment underlies chronic obstructive pulmonary disease (COPD) and predicts mortality. In the largest multi-ancestry genome-wide association meta-analysis of lung function to date, comprising 588,452 participants, we identified 1,020 independent association signals implicating 559 genes supported by ≥2 criteria from a systematic variant-to-gene mapping framework. These genes were enriched in 29 pathways. Individual variants showed heterogeneity across ancestries, age and smoking groups, and collectively as a genetic risk score showed strong association with COPD across ancestry groups. We undertook phenome-wide association studies for selected associated variants as well as trait and pathway-specific genetic risk scores to infer possible consequences of intervening in pathways underlying lung function. We highlight new putative causal variants, genes, proteins and pathways, including those targeted by existing drugs. These findings bring us closer to understanding the mechanisms underlying lung function and COPD, and should inform functional genomics experiments and potentially future COPD therapies.