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Genetically proxied circulating PD-1/PD-L1 levels and broadly defined myocarditis: A bidirectional Mendelian randomization study with exploratory lipidomic analyses.

Myocarditis is an inflammatory myocardial disease with potentially severe outcomes. Programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) regulate immune tolerance, but the association between lifelong genetically proxied circulating PD-1/PD-L1 levels and broadly defined myocarditis remains uncertain. We investigated these associations and explored related plasma lipid species. We conducted bidirectional 2-sample Mendelian randomization using proteomic genome-wide association data from the UK Biobank Pharma Proteomics Project and INTERVAL. FinnGen Release 10 was the primary broadly defined myocarditis outcome, and an independent myocarditis genome-wide association study (GCST90018882) provided outcome-level validation. Complementary estimators, heterogeneity and pleiotropy diagnostics, influence analyses, MR-RAPS, and supportive meta-analyses were performed. Associations with 179 plasma lipid species were examined in exploratory analyses. Higher genetically proxied circulating PD-L1 was inversely associated with broadly defined myocarditis in UKB-PPP (odds ratio [OR] 0.834, 95% confidence interval [CI] 0.698-0.995; P = .0441), and the independent INTERVAL analysis yielded a concordant inverse estimate (OR 0.619, 95% CI: 0.434-0.883; P = .0083); no clear association was observed for PD-1. The MR-RAPS estimate retained the inverse direction; estimates against the independent broadly defined myocarditis dataset were also inverse, and supportive meta-analyses across protein and outcome sources yielded inverse pooled estimates. Reverse MR did not support effects of broadly defined myocarditis liability on circulating PD-1 or PD-L1. Exploratory lipid analyses identified nominal associations requiring confirmation. Higher genetically proxied circulating PD-L1 may be associated with a lower risk of broadly defined myocarditis, supporting further investigation of PD-L1-related immune regulation. These findings do not directly estimate the effects of pharmacologic PD-1/PD-L1 blockade. The lipid findings are hypothesis-generating.

Myocarditis↗

Genetic Evidence Links Sex Hormone-binding Globulin to Total Body Bone Mineral Density at Age 45-60 Years: A Two-sample Mendelian Randomization Study.

The menopausal transition and early postmenopause represent important periods for women's skeletal health, but the genetic relevance of metabolic, behavioral, and hormone-related factors to bone mineral density during midlife remains incompletely understood. This study used publicly available genome-wide association study summary statistics to examine associations between body mass index, 25-hydroxyvitamin D, sex hormone-binding globulin, high-density lipoprotein cholesterol, smoking initiation, and alcohol intake frequency and total body bone mineral density at ages 45-60 years. Exposure genome-wide association study summary statistics were derived from large European-ancestry populations and were not restricted to midlife women, whereas the outcome genome-wide association study captured an age-stratified total body bone mineral density phenotype at age 45-60 years. This age range overlaps with the menopausal transition and early postmenopause in women. Univariable, reverse, and multivariable Mendelian randomization analyses were performed, with inverse-variance weighting as the primary method and complementary sensitivity analyses used to assess heterogeneity, pleiotropy, and result stability. Genetically predicted higher sex hormone-binding globulin was associated with lower total body bone mineral density (β = -0.111, 95% CI: -0.170 to -0.051; P = 0.0003). Reverse Mendelian randomization did not support reverse causation from bone mineral density to sex hormone-binding globulin. Multivariable analyses suggested that this association persisted after adjustment for selected metabolic biomarkers. The other examined exposures did not show consistent evidence of association. These findings provide genetic evidence linking sex hormone-binding globulin to total-body bone mineral density at ages 45-60 years. Further prospective and predictive studies are needed to evaluate its clinical relevance beyond established bone health assessment tools.

Humans↗

Exploring the causal role of plasma metabolites in pediatric asthma: a Mendelian randomization study.

BACKGROUND: Pediatric asthma (PA) is the prevailing chronic respiratory ailment in childhood. A better understanding of plasma metabolites is the goal for elucidating the molecular pathological mechanisms of PA and investigating novel therapeutic approaches. METHODS: Data for PA from Genome-Wide Association Studies (GWAS) was derived from the IEU-OpenGWAS project, featuring a collection of 1400 plasma metabolites. The inverse-variance weighting (IVW) method assessed causal relationships between plasma metabolites and PA, with measures taken to mitigate horizontal pleiotropy and heterogeneity. To select instrumental variables, a genome-wide significance threshold (p&#x2009;<&#x2009;5&#x2009;&#xd7;&#x2009;10-8) was applied to ensure robust genetic instruments. A Bonferroni correction controlled for multiple testing, with statistical significance defined as p&#x2009;<&#x2009;3.57&#x2009;&#xd7;&#x2009;10-5) (0.05/1400). To further substantiate outcomes, a reverse Mendelian randomization analysis was conducted. RESULTS: Research found 91 plasma metabolites linked to PA, ten of which showed significant associations. Of note, 20:4n6 levels (IVW: OR (95% CI) = 1.062 (1.030 to 1.094) and G/C16 (IVW: OR (95% CI) = 0.886 (0.832 to 0.943) were identified as pivotal exposure factors for PA. CONCLUSIONS: This study highlights 10 plasma metabolites that may have significant associations with PA incidence, with 20:4n6 levels and G/C16 potentially serving as valuable biomarkers for the early detection and management of PA.

Humans↗

Life-course influence of birthweight and subsequent pathways on healthy aging: a Mendelian randomization study.

BACKGROUND: Birthweight readily measurable marker of fetal growth that may influence health across the lifespan. We aimed to investigate the potential causal association between birthweight and healthy aging and to identify the mediating roles of subsequent socioeconomic, behavioral, functional, and disease-related factors to inform life-course strategies to promote healthy aging and reduce health inequities. METHODS: We performed two-sample Mendelian randomization analyses in European-ancestry participants to estimate the effect of birthweight (n&#x2009;=&#x2009;298,142-423,683) on two robust, composite healthy aging phenotypes (genetically independent phenotype of aging (aging-GIP) and multivariate aging-related genetic factor (mvAge)) and six individual aging phenotypes, including healthspan, resilience, parental lifespan, self-rated health, phenotypic age deceleration, and 90th percentile self-longevity (n&#x2009;=&#x2009;34,710-1,958,774), and screened for 100 candidate mediators (n&#x2009;=&#x2009;14,267-1,812,017) using a two-step mediation analysis. RESULTS: Genetically determined each 1-SD higher birthweight was associated with higher aging-GIP (&#x3b2; [95% CI] in different models ranging from 0.131 [0.066-0.196] to 0.162 [0.089-0.235] SDs) and mvAge (0.036 [0.010-0.063] to 0.045 [0.024-0.067]), independent of later-life obesity indicators; also with more interpretable benefits, including 12%-16% higher odds of longer healthspan, a 0.079-0.089 SD improvement in resilience, and a 1.22-1.74&#xa0;year increase in parental lifespan. Of 100 candidates, 26 and 25 mediated the effect of birthweight on aging-GIP and mvAge, respectively, including socioeconomic indicators (education, household income, occupational attainment; individual mediation proportion: 12.72%-27.79%); behaviors (e.g., cheese intake, age at first sex; 10.38%-29.56%); physical functions (e.g., blood pressure, grip strength; 7.57%-42.65%); and cardiometabolic diseases (e.g., type 2 diabetes, cardiovascular diseases; 25.02%-70.11%). CONCLUSIONS: Higher birthweight within the normal range directly promotes healthy aging, mediated by multifaceted modifiable factors. Our findings advocate adopting a life-course approach to foster healthy aging, starting with optimal birthweight and extending to interventions that enhance socioeconomic status, promote healthy behaviors, strengthen physical functions, and prevent cardiometabolic diseases.

Mendelian Randomization Analysis↗

Protein mediators of chronic kidney disease in Type 2 diabetes: A mendelian randomization study.

BACKGROUND: Chronic kidney disease (CKD) occurs in 20-50% of the people living with Type 2 diabetes (T2D) and is the leading cause of kidney failure worldwide. The cause of CKD is not fully understood, and few interventions prevent CKD in individuals living with diabetes. Here, we use large-scale proteomics data to identify circulating proteins that mediate the relationship between T2D and kidney disorders. METHODS AND FINDINGS: First, we used two-sample mendelian randomization (MR) and identified 71 circulating proteins whose levels were altered by genetic predisposition to T2D based on circulating proteomic GWAS from deCODE with 35,559 individuals and T2D GWAS with 80,154 cases. Then, we used cis-genetic variants to proxy the causal effect of some of these T2D-influenced circulating proteins and found that, collectively, five proteins (INHBC, GNPTG, LPO, AGRN, and CTSD) affected three kidney traits (blood urea nitrogen [BUN], estimated glomerular filtration rate [eGFR] and CKD risk) based on GWAS with up to 1,004,040 participants. Notably, we found that higher levels of circulating INHBC protein were estimated to lead to a lower eGFR and higher BUN based on MR analyses. We then replicated this MR analysis with proteomic GWAS from four additional cohorts, namely, UKB-PPP, Fenland, ARIC, and EPIC-Norfolk. We observed a consistent direction of effect across all four proteomic GWAS datasets, supporting the robustness of our results against platform and cohort variation. In observational analyses, increased circulating INHBC levels were associated with increased hazard for kidney disease diagnosis in 37,854 UK Biobank participants. We estimated that circulating INHBC levels mediate 1.3% (95% confidence interval [0.85%, 1.9%]) of the association between T2D and kidney disease diagnosis. There are important limitations in this study. Firstly, although we observed limited evidence for violations to the MR assumptions, some are untestable. Secondly, our study was not based on individuals with diabetic kidney diseases, but rather independent population-based studies assessing diabetes and kidney function separately. Therefore, additional functional analyses in disease specific cohort are needed. CONCLUSIONS: Collectively, these findings suggest that T2D influences the risk of CKD, in part, through increased circulating INHBC levels.

Humans↗

Education, socioeconomic status, leisure sedentary behaviors and female infertility: mendelian randomization study.

BACKGROUND: Previous studies have indicated that education, socioeconomic status, and leisure sedentary behavior may be associated with female infertility. However, it remains unclear whether these associations imply causal relationships. METHODS: Genetic variants from genome-wide association studies (GWAS) of education, socioeconomic status, and leisure sedentary behaviors were obtained from the UK Biobank and MRC-IEU database (Medical Research Council Integrative Epidemiology Unit), female infertility data was acquired from the FinnGen Biobank. Univariable and multivariable MR analyses were performed to explore the relationships between these traits and female infertility. RESULTS: The results of the univariate MR analysis indicated that age of full-time education had a protective effect on female infertility (odds ratio [OR] 0.471; 95% confidence interval [CI] 0.24 to 0.93; p&#x2009;=&#x2009;0.03). Multivariable MR and reverse MR studies support the existence of a relationship between them. However, no causal correlation was found between other traits and female infertility. No significant heterogeneity or horizontal pleiotropy was detected, and the stability of the results was confirmed through sensitivity analysis and the leave-one-out test. CONCLUSIONS: A later age of completion of full-time education may be causally related to a reduced risk of female infertility, but no causality is established between other educational levels factors, socioeconomic status, or sedentary behaviors and infertility risk.

Humans↗

The associations between functional dyspepsia and potential risk factors: A comprehensive Mendelian randomization study.

BACKGROUND: Previous cross-sectional studies have identified multiple potential risk factors for functional dyspepsia (FD). However, the causal associations between these factors and FD remain elusive. Here we aimed to fully examine the causal relationships between these factors and FD utilizing a two-sample MR framework. METHODS: A total of 53 potential FD-related modifiable factors, including those associated with hormones, metabolism, disease, medication, sociology, psychology, lifestyle and others were obtained through a comprehensive literature review. Independent genetic variants closely linked to these factors were screened as instrumental variables from genome-wide association studies (GWASs). A total of 8875 FD cases and 320387 controls were available for the analysis. The inverse variance weighted (IVW) method was employed as the primary analytical approach to assess the relationship between genetic variants of risk factors and the FD risk. Sensitivity analyses were performed to evaluate the consistency of the findings using the weighted median model, MR-Egger and MR-PRESSO methods. RESULTS: Genetically predicted depression (OR 1.515, 95% confidence interval (CI) 1.231 to 1.865, p = 0.000088), gastroesophageal reflux disease (OR 1.320, 95%CI 1.153 to 1.511, p = 0.000057) and years of education (OR 0.926, 95%CI 0.894 to 0.958, p = 0.00001) were associated with risk for FD in univariate MR analyses. Multiple medications, alcohol consumption, poultry intake, bipolar disorder, mood swings, type 1 diabetes, elevated systolic blood pressure and lower overall health rating showed to be suggestive risk factors for FD (all p<0.05 while &#x2265;0.00167). The positive causal relationship between depression, years of education and FD was still significant in multivariate MR analyses. CONCLUSIONS: Our comprehensive MR study demonstrated that depression and lower educational attainment were causal factors for FD at the genetic level.

Humans↗

Uncovering metabolite-immune interactions in the pathogenesis of psoriatic arthritis: A 2-sample Mendelian randomization study.

PsA is a chronic inflammatory joint condition associated with psoriasis, and its underlying mechanisms are not fully elucidated. Serum metabolites, as direct reflections of metabolic status, may influence disease progression by regulating immune cell function; however, the causal relationships and specific pathways require further investigation. The present investigation utilized a 2-sample bidirectional MR methodology, leveraging extensive pooled GWAS data to thoroughly evaluate the causal relationships between 1440 serum metabolites and PsA. Additionally, mediation MR analysis was performed to explore the possible mediating effects of 731 immune cell characteristics. In the primary analysis, inverse-variance weighted was employed, and this was further supported by various sensitivity analyses to confirm the reliability of the findings. The genetic method to infer causality analysis revealed significant positive causal associations between 10 serum metabolites and PsA risk, with quinolinate levels demonstrating the most significant correlation (OR&#x2005;=&#x2005;1.56, 95% CI: 1.26-1.93); while 4 metabolites (e.g., citrate levels, OR&#x2005;=&#x2005;0.74, 95% CI: 0.61-0.89) exhibited protective effects. Regarding immune cells, 6 cellular features (e.g., CD20 on B cells) were positively correlated with disease risk, whereas 5 features (primarily HLA-DR expression on monocyte subsets) showed negative correlations. Mediation analysis identified 3 significant pathways,the percentage of the effect explained by the mediator: N6,N6,N6-trimethyllysine levels mediated via B cells (CD20 on IgD+ CD38br), with a proportion of 33.2%; 1-stearoyl-2-docosahexaenoyl-GPE (18:0/22:6) levels mediated through monocytes (HLA-DR on CD14- CD16-) with a 32.0% proportion; the unknown metabolite X-24736 also mediated 42.1% of the protective effect via the same monocyte phenotype. This study revealed that elevated amino acid-related metabolites and glycerophospholipids significantly increase PsA risk through immune cell effects. These are closely associated with PsA pathogenesis and may serve as potential biomarkers. The novel findings underscore metabolic-immune interactions as targets for biomarkers and therapies in PsA, advancing personalized medicine.

Humans↗

Limits to causal inference based on Mendelian randomization: a comparison with randomized controlled trials.

"Mendelian randomization" refers to the random assortment of genes transferred from parent to offspring at the time of gamete formation. This process has been compared to a randomized controlled trial of genetic variants. This could greatly aid observational epidemiology by potentially allowing an unbiased estimate of the effects of gene products on disease outcomes. However, studies utilizing Mendelian randomization to estimate effects of gene products on outcomes should be interpreted with caution. In this paper, the authors discuss some of the challenges facing epidemiologists in the analysis and interpretation of Mendelian randomization studies, particularly those that become apparent when the analogy with randomized controlled trials is closely examined. The authors conclude that Mendelian randomization is a powerful addition to etiologic research tools. However, care must be taken, because drawing valid causal inferences from its application depends upon more extensive assumptions than are required in randomized controlled trials.

Causality↗

Meta-analysis of genetic studies using Mendelian randomization--a multivariate approach.

In traditional epidemiological studies the association between phenotype (risk factor) and disease is often biased by confounding and reverse causation. As a person's genotype is assigned by a seemingly random process, genes are potentially useful instrumental variables for adjusting for such bias. This type of adjustment combines information on the genotype-disease association and the genotype-phenotype association to estimate the phenotype-disease association and has become known as Mendelian randomization. The information on genotype-disease and genotype-phenotype may well come from a meta-analysis. In such a synthesis, a multivariate approach needs to be used whenever some studies provide evidence on both the genotype-phenotype and genotype-disease associations. This paper presents two multivariate meta-analytical models, which differ in their treatment of the heterogeneities (between-study variances). Heterogeneities on the genotype-phenotype and genotype-disease associations may be highly correlated, but a multivariate model that parameterizes the heterogeneity directly is difficult to fit because that correlation is poorly estimated. We advocate an alternative model that treats the heterogeneities on genotype-phenotype and phenotype-disease as being independent. This model fits readily and implicitly defines the correlation between the heterogeneities on genotype-phenotype and genotype-disease. We show how either maximum likelihood or a Bayesian approach with vague prior distributions can be used to fit the alternative model.

Coronary Disease↗

Positive association between apolipoprotein B and colorectal cancer risk: Findings from a 14-year follow-up cohort study and Mendelian randomization analyses.

BACKGROUND: The effects of lipid traits on colorectal cancer (CRC) risk and the extent to which obesity may modify these effects remain unclear. OBJECTIVE: To examine the associations between lipid traits and CRC risk using an observational study and Mendelian randomization (MR) analyses, and the role of weight status in the potential associations. METHODS: In the Guangzhou Biobank Cohort Study (GBCS), lipid profiles were measured during 2003-2008, and CRC events were identified through record linkage with the cancer registry. MR analyses assessed the causal effects of lipid traits on CRC using a genome-wide association study meta-analysis of 185,616 Europeans. RESULTS: Among 28,576 GBCS participants followed until 2020, 599 CRC events occurred. Participants in the highest quartile of apolipoprotein B (apoB) had a higher CRC risk (hazard ratio [HR] 1.43, 95% CI&#xa0;1.02-2.01). This association remained in those with overweight/obesity (HR 2.21, 95% CI 1.28-3.83). MR analyses supported a detrimental effect of apoB on CRC (odds ratio 1.12 per 1 SD, 95% CI 1.02-1.22). MR analyses also showed positive associations for total cholesterol and the apoB/apolipoprotein A-I ratio, which were not significant in the observational study. CONCLUSION: Higher apoB levels were associated with an increased CRC risk in both observational and MR analyses, suggesting a potential role of apoB in CRC prevention, especially among participants with overweight/obesity. However, the limitations of single-time lipid measurements and the use of different ancestries across study designs indicate the need for further research to confirm the robustness and generalizability of the findings.

Humans↗

An integrated approach to the meta-analysis of genetic association studies using Mendelian randomization.

A natural randomization process, sometimes called Mendelian randomization, occurs at conception to determine a person's genotype. By combining information from genotype-disease and genotype-phenotype studies, it is possible to use this Mendelian randomization to derive an estimate of the association between phenotype (risk factor) and disease that is free of the confounding and reverse causation typical of classical epidemiology. When one is synthesizing evidence, studies evaluating genotype-phenotype associations, studies evaluating genotype-disease associations, and studies evaluating both are encountered, and methods should be used that allow for this structure. Plotting the log odds ratio of genotype-disease against the mean genotype-phenotype difference may help investigators detect departures from the assumptions underlying Mendelian randomization. Testing for differences between studies reporting on only the genotype-phenotype or genotype-disease association and those reporting on both associations may help in detecting reporting bias. This integrated approach to the meta-analysis of genotype-phenotype and genotype-disease studies is illustrated here using the example of the methylenetetrahydrofolate reductase (MTHFR) gene, homocysteine level, and coronary heart disease. An integrated meta-analytical approach may increase the precision of this estimate and provide information on the assumptions underlying Mendelian randomization. Serious biases may arise if the assumptions behind the analysis based on Mendelian randomization are not met.

Confidence Intervals↗

Validation of breast cancer as a risk factor for anxiety and depression: Insights from Mendelian randomization analysis.

This study employed Mendelian randomization (MR) analysis to confirm the association between breast cancer and the risk of anxiety and depression, and to explore the molecular mechanisms by which lipid nanoparticles of ketamine (LNP@Ket) modulate these behaviors in a mouse model of breast cancer. Through single-cell transcriptomic analysis, the study aimed to clarify nuclear factor erythroid 2-related factor 2 (Nrf2)'s role in the development of anxiety and depression in these mice. Analysis of patient data from genome-wide association study (GWAS) databases supported the link between breast cancer, anxiety, and depression. In vivo experiments demonstrated that treating breast cancer mice with LNP@Ket significantly reduced anxiety and depression behaviors. The synthesis of LNP@Ket and its subsequent analysis highlighted its inhibitory effects on these behaviors. Single-cell transcriptomic sequencing identified key cells and genes affected by LNP@Ket treatment, particularly emphasizing Nrf2. Upregulation of Nrf2 in astrocytes increased the expression of antioxidant enzymes and reduced pro-inflammatory cytokines, alleviating anxiety and depression symptoms by inhibiting neuroinflammation and neurodegeneration. This comprehensive study highlights the pivotal role of Nrf2 in the therapeutic efficacy of LNP@Ket for treating anxiety and depression in breast cancer mice.

Anxiety and depression behaviors↗

Can we identify people with Alzheimer's disease from examination of the eye? A bidirectional Mendelian randomization (MR) study.

BACKGROUND: Neurodegeneration in Alzheimer's disease (AD) is thought to be driven by amyloid-beta and tau deposition in the cerebral vasculature and brain. As the eye is an extension of the central nervous system, this study aimed to determine which neurovascular and neuroretinal changes in the eye are caused by AD rather than associations of the disease. METHODS: Bidirectional two-sample univariable and multivariable Mendelian randomization (MR) methods were applied. Instrumental variables were derived from genome-wide association studies (GWAS) of AD and the following ocular features: thickness measurements of central macula (MT), retinal nerve fibre layer (mRNFL), ganglion cell-inner plexiform layer (mGCIPL), outer nuclear layer (ONL), inner segment layer (IS), and outer segment (OS) from macular region OCT scans; arteriolar tortuosity (AT), venular tortuosity (VT), venular width (VW), fractal dimension (FD), vertical cup-to-disc ratio (VCDR), optic cup area (OCA), and optic disc area (ODA) derived from other imaging methods. RESULTS: There was strong evidence that genetic liability to AD affected the retinal vasculature by specifically increasing AT (&#x3b2; = 0.007;95%CI=0.002,0.011;p-value=0.005) in UK Biobank participants (n=52,798). AD may influence the mRNFL (&#x3b2;=-0.047,95%CI=-0.119,0.023,p-value=0.18) and mGCIPL (&#x3b2;=-0.061;95%CI=-0.14,0.025,p-value=0.16) of the inner retina and OS layer (&#x3b2; = 0.044;95%CI=-0.0001,0.08;p-value=0.05) but the evidence was weak. Multivariable MR analysis showed that a causal relationship between optic disc area and AD (OR=0.76;95%CI=0.62,0.93,p-value=0.009) was probably mediated by refractive error. CONCLUSION: Early cerebrovascular signs of AD may be detected by examination of the eye. Further investigation is required to determine the clinical utility of eye screening for dementia.

Humans↗

Genetic and epigenetic underpinnings of biological aging: a multi-omics study integrating Mendelian randomization, spatial transcriptomics, and drug target discovery.

Inflammaging represents a hallmark of biological aging, yet the causal inflammatory mediators driving multi-dimensional epigenetic aging and their effector genes remain poorly characterized at the genetic level. We developed a four-tier analytical framework integrating causal screening, multi-omics effector gene mapping, spatial transcriptomics, and drug target evaluation. Two-sample Mendelian randomization (MR) of 91 circulating inflammatory proteins against six aging phenotypes identified IL-12B, IFNG, and IL-2 as the most robust pro-aging mediators with consistent effects across independent outcomes. Using multi-omics summary-based MR (SMR) as the core analytical engine, we integrated four-layer whole-blood molecular QTL resources eQTL (eQTLGen, n = 31,684), sQTL (GTEx, n = 755), pQTL (INTERVAL + SCALLOP, n = 34,232), and mQTL (McRae et al., n = 1,980) - with GWAS summary statistics for four epigenetic age acceleration measures. At a stringent threshold (P_SMR < 1&#xd7;10&#x207b;&#xb9;&#xb2;), seven high-confidence effector genes were identified: NHLRC1, TPMT, SELP, and RIPPLY3 for IEAA; ZNF373A and PLDN for HannumAA; and EDARADD for PhenoAA. The chromosome 6p21 NHLRC1-TPMT locus, overwhelmingly driven by methylation QTL signals (-log&#x2081;&#x2080;P = 26.06), emerged as the dominant genetic node of epigenetic aging. Spatial projection via gsMap onto a mouse E16.5 embryo atlas (121,767 cells) revealed preferential enrichment in smooth muscle and lung, with EDARADD showing marked specificity in mucosal epithelium. Cross-database drug target mining classified TPMT and SELP as repurposable known targets and NHLRC1 as a high-priority novel druggable candidate. This study provides multi-omics convergent causal evidence for inflammation-driven epigenetic aging and delivers genetically anchored targets for precision anti-aging intervention.

Aging↗

Possible linking and treatment between Parkinson's disease and inflammatory bowel disease: a study of Mendelian randomization based on gut-brain axis.

BACKGROUND: Mounting evidence suggests that Parkinson's disease (PD) and inflammatory bowel disease (IBD) are closely associated and becoming global health burdens. However, the causal relationships and common pathogeneses between them are uncertain. Furthermore, they are uncurable. Thus, we aimed to identify the causal relationships and novel therapeutic targets shared between them based on their common pathophysiological mechanisms in gut-brain-axis (GBA). METHODS: A meta-analysis on bidirectional Mendelian randomization (MR) utilizing various datasets was performed to estimate their causal relationship. Then, pleiotropic analysis under the composite null hypothesis (PLACO) with functional mapping combined with annotation of genetic associations (FUMA) analysis were conducted to identify pleiotropic genes. Next, blood, brain and intestine expression quantitative trait locus (eQTL) were taken to perform drug-target MR finding common causal genes in two diseases. Colocalization analysis ensured the eQTLs of corresponding gene colocalized with disease. Enrichment analysis and protein&#x2012;protein interaction (PPI) network were done to explore common pathogenesis pathways. Genes passed all analysis were regarded as drug targets. RESULTS: Our MR meta-analysis revealed the bidirectional causal relationship between diseases, with combined ORs for PD on IBD, CD, UC (1.050 [95% CI 1.014-1.086], 1.044 [95% CI 0.995-1.095], 1.063 [95% CI 1.016-1.120]); for IBD, CD, UC on PD (1.003 [95% CI 0.973-1.034], 1.035 [95% CI 1.004-1.067], 1.008 [95% CI 0.977-1.040]). Overall, 277, 216 and 201 genes were identified as pleiotropic genes between PD and IBD, CD, UC. Total of 733 genes were classified as tier 3 (found in only one tissue) druggable targets, 57 as tier 2 (found in two tissues, 51 protein-coding genes) and 9 as tier 3 (found in three tissues). Among 60 protein-coding druggable targets over tier 2, 18 overlapped with pleiotropic genes and enriched in mitochondria, antigen presentation, processing and immune cell regulation pathways. Three druggable genes (LRRK2, RAB29 and HLA-DQA2) passed colocalization analysis. LRRK2 and RAB29 were reported to be pleiotropic genes, and RAB29 and HLA-DQA2 were reported for the first time as potential drug targets. CONCLUSIONS: This study established a reliable causal relationship, possible shared drug targets and common pathogenesis pathways of two diseases, which had important implications for intervention and treatment of two diseases simultaneously.

Humans↗

Mendelian Randomization Using a Japanese GWAS Identifies an HLA-Linked Causal Effect of Chronic Hepatitis B on Cholangiocarcinoma Risk.

BACKGROUND: Cholangiocarcinoma (CCA) is a highly malignant cancer that develops in the bile ducts. Its incidence is particularly high in East Asian populations, but the underlying genetic factors remain unclear. To investigate potential risk factors for CCA, we conducted a Mendelian randomization study to infer causality. METHODS: Using large-scale genome-wide association study data from the BioBank Japan resource, we systematically investigated the causal effects of genetic predisposition to seven conditions, chronic hepatitis B (CHB), chronic hepatitis C, autoimmune hepatitis, type 1 diabetes, type 2 diabetes, chronic gastritis, and chronic pancreatitis, on CCA risk. RESULTS: Our analysis reveals a significant association between genetic susceptibility to CHB with a 24% higher likelihood of developing CCA than non-susceptible individuals (Inverse-Variance Weighted Odds Ratio = 1.24, 95% Confidence Interval: 1.08-1.42; p = 0.002). This genetic association is significantly driven by instrumental variables enriched in the immune-regulatory HLA class II region (6p21), suggesting a plausible biological mechanism. For the primary outcome (CCA), statistical significance was assessed across seven exposures at a Bonferroni-corrected threshold (two-sided p<0.0071). Notably, the CHB-CCA association remains significant after correction. This primary finding is strongly supported by comprehensive sensitivity analyses that showed no evidence of confounding by horizontal pleiotropy or heterogeneity. Conversely, no significant causal effects on CCA were identified for the other six conditions. CONCLUSIONS: Our MR analysis supports a causal role of HBV infection in CCA development, highlighting the importance of targeted HBV screening and surveillance.

Female↗

THE CAUSAL ASSOCIATION OF CARDIOMETABOLIC DISEASES AND SEPSIS-RELATED OUTCOMES: A MENDELIAN RANDOMIZATION AND POPULATION STUDY.

Objective: The causality between cardiometabolic disease (CMD) and sepsis has remained largely unknown. To elucidate this, we conducted a Mendelian randomization (MR) and population study. Methods: First, we used univariable and multivariable MR analyses to investigate causal associations between CMD and sepsis-related outcomes. We obtained genome-wide association study summary from both the MRC Integrative Epidemiology Unit and the FinnGen consortium. Subsequently, a two-step mediation MR analysis was performed to explore mediators. Afterward, we conducted an observational study using the Medical Information Mart for Intensive Care IV database, in which multivariable logistic regression models were utilized to examine the relationship between CMD and sepsis-related outcomes. Results: In the MR study, type 2 diabetes mellitus (OR = 1.058, 95% CI = 1.017-1.100, P = 0.005), obesity (OR = 1.113, 95% CI = 1.057-1.172, P < 0.001), and heart failure (HF) (OR = 1.178, 95% CI = 1.063-1.305, P = 0.002) were independently causally related to sepsis. Obesity (OR = 1.215, 95% CI = 1.027-1.437, P = 0.023) and HF (OR = 1.494, 95% CI = 1.080-2.065, P = 0.015) also showed independent causal associations with sepsis critical care admission. Mediation MR analysis identified 23 blood metabolites potentially causally linked to sepsis ( P < 0.05), yet none mediated the relationship between CMD and sepsis. In the observational study, we found associations between sepsis and several conditions including type 2 diabetes mellitus, obesity, hypertension, stroke, HF, and hyperlipidemia after adjusting for confounding factors. Moreover, hypertension, stroke, HF, coronary artery disease, and hyperlipidemia were linked to sepsis critical care admission. Conclusion: This study has, for the first time, revealed indicative evidence of a causal relationship between CMD and sepsis through observational and genetic evidence. Taken together, clinical attention to sepsis may be warranted among patients with CMD.

Humans↗