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Genetic evidence for causality of late chronotype on metabolic syndrome in East Asians and Europeans.

CONTEXT: The impact of chronotype-defined as an individuals' inherent preference of sleep timing-and its genetic determinants on metabolic syndrome (MetS) has been less studied. OBJECTIVE: This study investigated the causal relationship between late chronotype and MetS using Mendelian randomization (MR) analysis, based on data from the Taiwan Biobank (TWB) and parallel analyses in the UK Biobank (UKB). METHODS: A total of 36,845 participants from TWB served as the discovery cohort, and 235,639 participants from UKB served as the replication cohort. Late chronotype was defined in TWB as a preference for bedtime after midnight, and in UKB as self-report as being an 'evening' person. The association between late chronotype and MetS, along with its components, was evaluated in TWB, and validated in UKB. Genome-wide association analyses for late chronotype were first conducted in TWB and then meta-analyzed with UKB. Polygenic risk scores (PRS) for late chronotype were constructed and tested for association with MetS. Causality between late chronotype and MetS was examined using one-sample MR analysis in TWB and validated in UKB. RESULTS: Late chronotype was significantly associated with MetS, as well as with central obesity, hyperglycemia, and hypertriglyceridemia, in both TWB and UKB (all P&#xa0;<&#xa0;0.0083, considering Bonferroni correction). The constructed PRS of late chronotype also showed significant associations with MetS and several of its components (several P&#xa0;<&#xa0;0.0083, considering Bonferroni correction). Findings from the one-sample MR analysis indicated a potential causal effect of late chronotype on MetS. CONCLUSIONS: This study provides evidence of a robust association between late chronotype and MetS across populations of diverse ancestry, including Taiwanese and European.

Humans↗

Global burden of peripheral arterial disease (1990-2021), global burden trends and the impact of blood lead on peripheral arterial disease: a multidimensional analysis based on NHANES, GBD, and Mendelian randomization.

OBJECTIVE: Peripheral arterial disease (PAD) is a common cardiovascular disease that it is an important reason for the decline of patients' quality of life and the increase of family economic burden. To systematically evaluate the association between environmental lead exposure and peripheral arterial disease (PAD) and to characterize the global distribution of PAD disease burden, while exploring differences among regions with varying socioeconomic development. METHODS: Using data from the National Health and Nutrition Examination Survey (NHANES), the Global Burden of Disease (GBD) database, and genome-wide association studies (GWAS), we employed multivariable logistic regression to examine the link between lead exposure and PAD. Mendelian randomization (MR) was used to infer causality, and we analyzed PAD disease burden trends across countries of differing income levels. RESULTS: The burden on PAD patients worldwide shows a downward trend. In high SDI and high middle SDI countries, the burden of PAD gradually decreases, while in low middle SDI and low SDI countries, the burden of PAD gradually decreases. After adjusting for potential confounders, a significant dose-response relationship was observed between blood lead levels and PAD risk (OR&#x2009;=&#x2009;1.04, 95% CI: 1.00-1.09). This association was more pronounced among males (OR&#x2009;=&#x2009;1.07, 95% CI: 1.05-1.09), individuals with higher education (OR&#x2009;=&#x2009;1.24, 95% CI: 1.16-1.32), and patients with hypertension (OR&#x2009;=&#x2009;1.07, 95% CI: 1.05-1.09). MR analysis supported a causal link between lead exposure and PAD. Global trend analysis indicated that PAD burden is declining in high-income countries but rising in low-income regions, highlighting significant health inequities. CONCLUSION: Environmental lead exposure is significantly associated with increased PAD risk, with notable differences in population susceptibility. These findings underscore the necessity of environmental exposure control and tailored prevention strategies to enhance cardiovascular health worldwide.

Humans↗

Exploring the role of gut microbiota in coronary atherosclerosis through lipoprotein-mediated cholesterol transport and distribution: A Mendelian randomization analysis.

We employed Mendelian randomization (MR) to explore causal relationships between gut microbiota (GM), coronary atherosclerotic heart disease (CAHD), and potential metabolic mediators. We utilized summary statistics from genome-wide association studies (GWAS), encompassing data on 473 GM traits from comprehensive microbiome GWAS, 61 lipoprotein-mediated cholesterol transport and distribution data from large-scale metabolic biomarker studies, and coronary atherosclerosis (CA) data from the GWAS catalog (study accession GCST90043957) involving 456,348 European participants. Bidirectional MR analyses were conducted to investigate the causal relationships between GM and CA. Two-sample Mendelian randomization analyses were performed to identify potential mediating metabolites and quantify the mediation proportion. Ultimately, the GM GCA-900066755, identified through MR as having a potential causal relationship, was selected to investigate its potential effects on CA by influencing cholesterol transport and distribution. Our results indicated that GCA-900066755 was positively associated with an increased risk of CA (odds ratio&#x2005;=&#x2005;1.156). CA did not significantly affect the levels of GCA-900066755 (odds ratio&#x2005;=&#x2005;1.009). GCA-900066755 was negatively correlated with total cholesterol levels in medium high-density lipoprotein, which reduced CA risk, and was positively correlated with total cholesterol levels in low-density lipoprotein (LDL), large LDL, medium LDL, and small LDL, which were positively associated with CA. Mediation analysis showed 7 data points mediating the association between GCA-900066755 and CA. Our MR study supports a causal relationship between specific GM groups and the risk of CAHD, highlighting that cholesterol traits are not merely outcomes associated with the relationship between GM and CAHD, but are important mediating factors. Understanding the biological mechanisms of these traits can provide a concrete foundation for future targeted interventions.

Mendelian Randomization Analysis↗

The role of ferroptosis in juvenile idiopathic arthritis: Causal inference and mediation by immune phenotypes.

This study employed a bidirectional 2-step, two-sample Mendelian randomization approach to investigate the causal relationships between ferroptosis-related genes and juvenile idiopathic arthritis (JIA) and to explore the mediating role of immune cells. Ferroptosis genes were identified from the deCODE database and matched with protein quantitative trait locus data as exposures to evaluate their causal effects on JIA, while immune cell traits were similarly assessed. For genes showing positive Mendelian randomization results, further analyses were conducted to determine whether immune cells mediated the effects on JIA, with mediation analysis performed only in the presence of causal associations. Data were sourced from the GWAS, FerrDb, and other public repositories. Nine ferroptosis-related genes were found to have causal links with JIA: HSPB1, DECR1, LIFR, and CTSB increased JIA risk, whereas PIEZO1, DPP4, BID, and others were protective. Forty immune cell traits were also causally associated with JIA. Mediation analysis revealed that several immune cells, including CD127- CD8+ T cells, partially mediated the genetic effects, with mediation proportions reaching up to 18.6%. Collectively, these results point to a ferroptosis-immune-JIA axis, suggesting that ferroptosis-related genes contribute to JIA pathogenesis through immune cell mediation and offering new mechanistic insights and potential therapeutic targets.

Arthritis, Juvenile↗

Fibrinogen and coronary heart disease: test of causality by 'Mendelian randomization'.

BACKGROUND: Blood concentrations of fibrinogen have been associated with coronary heart disease risk in epidemiological studies, but it is uncertain whether this association is causal or reflects residual confounding by other risk factors. We investigated the relationship between the single nucleotide polymorphism at position -148 in the beta-fibrinogen gene promoter (beta - 148C/T), blood fibrinogen levels, and risk of myocardial infarction (MI) in sufficiently large numbers of coronary disease cases to reliably address this question. METHODS: Genotyping and measurement of blood fibrinogen concentration were carried out in 4,685 cases of confirmed MI and 3,460 controls with no history of coronary disease. A meta-analysis of ISIS and 19 other studies of beta-fibrinogen genotypes involving a total of 12,220 coronary disease cases and 18,716 controls was conducted. RESULTS: Among the ISIS controls, mean plasma fibrinogen concentrations with the C/C, C/T and T/T genotypes were 3.34 (SE 0.015), 3.48 (0.022), and 3.60 (0.064) g/l, respectively, corresponding to an increase of 0.14 (0.024) g/l per T allele (trend P < 0.0001). In the case-control comparison, 0.14 g/l higher usual plasma fibrinogen concentration was associated with an age-adjusted and sex-adjusted risk ratio for MI of 1.17 [95% confidence interval (95% CI) 1.14-1.19; P < 0.0001]. But, after further adjustment for smoking, body mass index, and plasma apolipoprotein B/A(1) ratio, this risk ratio fell to 1.03 (95% CI 1.00-1.05; P = 0.05). Moreover, fibrinogen genotype was not significantly associated with MI incidence: risk ratio of 1.06 (95% CI 0.96-1.16) per higher-fibrinogen allele in ISIS alone and of 1.00 (95% CI 0.95-1.04) per allele in the meta-analysis. CONCLUSIONS: Genotypes that produce lifelong differences in fibrinogen concentrations do not materially influence coronary disease incidence. As these genotype-dependent differences in fibrinogen were allocated randomly at conception (Mendelian randomization), this association is not likely to be confounded by other factors. Consequently, these genetic results provide strong evidence that long-term differences in fibrinogen concentrations are not a major determinant of coronary disease risk.

Adult↗

Integration of Genome-Wide Association Studies With Single-Cell and Bulk Expression Quantitative Trait Locus to Identify Stroke Susceptibility Genes.

BACKGROUND: Previous studies have integrated genome-wide association studies with expression quantitative trait locus (eQTL) data from bulk tissues to identify stroke susceptibility genes. However, eQTL data exhibit high cell-type specificity, and genetic variants may have distinct effects across stroke subtypes. METHODS: We applied the summary-data-based Mendelian randomization (MR) method to integrate eQTL data from 7 brain cell types with genome-wide association studies data for 5 stroke phenotypes (stroke, ischemic stroke, cardioembolic stroke, large artery stroke, and small vessel stroke). Results were compared with summary-data-based MR using eQTL data from 49 tissues in the Genotype-Tissue Expression project. Robustness of significant single-cell summary-data-based MR associations was assessed via MR and colocalization analyses. Further evaluations included single-cell RNA-seq differential expression, protein-protein interaction, druggability, and phenome-wide association studies. RESULTS: Single-cell summary-data-based MR identified many novel significant genes not detected using bulk tissue eQTL data. Validated associations revealed 2 stroke risk genes (LRCH1, ICA1L), 3 stroke protective genes (AHI1, LYRM9, CENPQ), 2 large artery stroke risk genes (LIPA, ELL), and 1 ischemic stroke protective gene (CENPQ). Single-cell RNA-seq showed significantly increased LIPA expression in mouse stroke samples compared with controls. Protein-protein interaction and druggability analyses, along with phenome-wide association studies, prioritized LIPA and LRCH1 as potential therapeutic targets for stroke while indicating possible adverse effects. CONCLUSIONS: Integrating single-cell eQTL with stroke-subtype genome-wide association studies uncovers novel cell-type-specific causal genes and highlights promising therapeutic targets, advancing understanding of stroke pathogenesis.

Genome-Wide Association Study↗

MONOCYTES AND B CELLS MEDIATE ALTERATIONS IN THE GENETIC ASSOCIATION BETWEEN PLATELETS AND SEPSIS VIA CLEC SIGNALING PATHWAY.

Background: Sepsis is a life-threatening condition characterized by multiple organ dysfunction. Blood cells abnormalities play a significant role in the onset and progression of sepsis; however, the potential causal relationship between platelets and sepsis remains unclear, as does whether immune cells mediate the interaction between platelets and sepsis. This study aims to explore the potential causal relationship between platelets and sepsis and analyze the mediating effect of immune cells. In addition, cell-to-cell communication was analyzed to explore the interaction between blood cells and immune cells. Material and methods: In this study, genome-wide association study data were utilized to examine the association between blood cells and sepsis. Two-sample Mendelian randomization (MR) and reverse MR were performed to investigate the potential causal relationship between blood cells and sepsis, with a specific focus on the relationship between platelets and sepsis. Subsequently, two-step MR was employed to identify the immune cells that mediate the interaction between platelets and sepsis and to assess their potential mediating effects. Cellchat software was used to analyze cell-to-cell communication. Results: The results of two-sample MR indicated that platelets were negatively correlated with sepsis (OR = 0.976, 95% CI 0.959-0.993, P = 0.005), suggesting that platelets have a protective effect against sepsis. Additionally, reverse MR demonstrated that sepsis had no significant effect on platelets (OR = 0.909, 95% CI 0.156-5.296, P = 0.916). The mediating effect analysis revealed that monocytes and B cells were important mediators in the relationship between platelets and sepsis. Notably, the correlation between platelets and sepsis shifted from negative to positive with the involvement of monocytes and B cells. The number and strength of cell-cell interactions were decreased in sepsis. Monocytes and B cells primarily regulate platelets through the CLEC signaling pathway, contributing to the pathogenesis of sepsis. Conclusion: This study confirmed the protective role of platelets in sepsis. Monocytes and B cells mediate changes in the genetic association between platelets and sepsis. Monocytes and B cells primarily interact with platelets via the CLEC pathway, thereby modulating the genetic association between platelets and sepsis. These findings indicate that thrombocytopenia, especially when accompanied by elevated monocytes and B cells, may serve as a potential marker for sepsis.

Humans↗

Genetic insights into the relationship between age at menarche and mental health-related phenotypes.

BACKGROUND: Multiple observational studies have reported associations between age at menarche (AAM) and mental health problems, yet their shared genetic architecture remains poorly characterized. METHODS: We leveraged genome-wide association study summary statistics for AAM and 15 mental health-related phenotypes. We conducted a multi-method integrative analysis encompassing linkage disequilibrium score regression, pleiotropic analysis under the composite null hypothesis, functional mapping and annotation, multi-marker analysis of genomic annotation, pathway enrichment, and bidirectional two-sample Mendelian randomization (MR) to explore shared genetic architecture and potential causal relationships. RESULTS: Our study identified significant genetic correlations between AAM and eight mental health-related phenotypes (miserableness, fed-up feelings, nervous feelings, ever thought that life is not worth living, ever self-harmed, depression, ever smoker, and age started smoking in former smokers). A total of 155 pleiotropic loci, 18 colocalized loci (e.g., 6q16.3), and 203 pleiotropic genes (e.g., LIN28B) were identified. These genes are expressed in multiple regions, including the cerebral cortex and hypothalamus, and are involved in various biological processes and signaling pathways. Additionally, MR analysis revealed causal associations between AAM and 5 mental health-related phenotypes (mood swings, miserableness, fed-up feelings, and age at which smokers started smoking in former/current smokers). CONCLUSIONS: Our study revealed extensive genetic associations between AAM and mental health-related phenotypes, and further explored the potential causal relationships between them. These findings enhance our understanding of the relationship from a genetic perspective and establish a foundation for future research to explore the biological pathways and environmental interactions contributing to these associations.

Genome-Wide Association Study↗

Cerebral Cortical Structural Variation and General Cognitive Ability: Evidence From Mendelian Randomization.

Understanding the cortical architecture underlying individual differences in general cognitive ability (GCA) remains a central question in cognitive neuroscience. Prior work has established associations between global brain size and GCA, yet the regional effects and directionality of these relationships remain debated. Using a genetically informed cortical parcellation in 11,289 UK Biobank participants, we examined associations between cortical surface area (SA), cortical thickness (CT), and GCA measured via verbal-numerical reasoning. Total SA showed a robust positive association with GCA. At the regional level, dorsolateral prefrontal and superior temporal SA exhibited the strongest positive associations, which persisted after adjustment for global SA. In contrast, CT showed comparatively modest associations. Using Mendelian randomization (MR) with genome-wide significant genetic instruments, we observed evidence consistent with a bidirectional relationship between total SA and GCA. At the regional level, dorsolateral prefrontal and temporal SA demonstrated evidence of MR-inferred directional effects on GCA, while GCA showed evidence of MR-inferred directional effects on total SA and perisylvian thickness. These findings support a polyregional SA architecture underlying GCA, with prominent contributions from prefrontal and temporal association cortices. Our results refine global brain-GCA models and highlight the value of genetically informed parcellation for identifying regional cortical contributions.

Humans↗

Use of single-nucleotide polymorphisms in the search for genetic modifiers of the uremic phenotype.

As the modern nephrology community continues to be burdened with growing numbers of patients with end-stage renal disease (ESRD) and exceptionally high mortality rates, it is obvious that progress in the development of preventive and therapeutic strategies has not been sufficient. This urges nephrologists to focus on the underlying mechanisms for ESRD morbidity and mortality, and in particular on cardiovascular disease (CVD), which is the major contributor to premature death in this patient group. The high prevalence of inflammation, vascular ossification, and oxidative stress in ESRD predisposes these patients to CVD. Because genetic risk factors may modulate the pathophysiologic response, genotype-phenotype association studies may provide ways of predicting individual disease progression and may shed some light on key regulatory pathways. Indeed, recent genetic association studies show that polymorphisms in candidate genes related to inflammatory signaling, vascular ossification, and oxidative stress response influence the uremic phenotype. DNA polymorphisms may also be used as nonconfounded tools in observational studies conducted to test causality, as stated by the mendelian randomization approach. To date, the collection of genetic data is no longer a limitation because genetic information is easily accessible in public databases and high-throughput genotyping technologies are available. Advanced bioinformatic tools are now warranted to facilitate the integration of accumulating genetic information with clinical and biochemical end points and, finally, to implement genotype-phenotype data in the care of patients with renal failure to better identify patients at high risk and to design novel personalized therapeutic and preventive strategies.

Calcinosis↗

Non-Mendelian transmission in dentatorubral-pallidoluysian atrophy and Machado-Joseph disease: the mutant allele is preferentially transmitted in male meiosis.

Autosomal dominant dentatorubral-pallidoluysian atrophy (DRPLA) and Machado-Joseph disease (MJD) are neurodegenerative disorders caused by CAG trinucleotide repeat expansions. An inverse correlation of age at onset with the length of the expanded CAG trinucleotide repeats has been demonstrated, and the intergenerational instability of the length of the CAG trinucleotide repeats, which is more prominent in paternal than in maternal transmissions, has been shown to underlie the basic mechanisms of anticipation in DRPLA and MJD. Our previous observations on DRPLA and MJD pedigrees, as well as a review of the literature, have suggested that the numbers of affected offspring exceed those of unaffected offspring, which is difficult to explain by the Mendelian principle of random segregation of alleles. In the present study, we analyzed the segregation patterns in 211 transmissions in 24 DRPLA pedigrees and 80 transmissions in 7 MJD pedigrees, with the diagnoses confirmed by molecular testing. Significant distortions in favor of transmission of the mutant alleles were found in male meiosis, where the mutant alleles were transmitted to 62% of all offspring in DRPLA (chi2 = 7.69; P<.01) and 73% in MJD (chi2 = 6.82; P<.01). The results were consistent with meiotic drive in DRPLA and MJD. Since more prominent meiotic instability of the length of the CAG trinucleotide repeats is observed in male meiosis than in female meiosis and meiotic drive is observed only in male meiosis, these results raise the possibility that a common molecular mechanism underlies the meiotic drive and the meiotic instability in male meiosis.

Adolescent↗

From genetic causality to druggable targets: A multiomics framework identifies ZSCAN16 in gout pathogenesis.

ObjectiveGout is a prevalent form of inflammatory arthritis in which many patients respond suboptimally to current therapies. Drug development is hampered by a lack of genetically validated targets, leading to high clinical trial attrition. This study aimed to systematically identify and prioritize novel, druggable targets for gout via a multilayered genetic and functional genomics approach.MethodsWe performed two-sample Mendelian randomization (MR) using cis-expression quantitative trait locus (cis-eQTL) data and dual independent gout genome-wide association study (GWAS) cohorts (openGWAS and FinnGen). The candidate genes were subjected to a rigorous validation pipeline including Bayesian colocalization, phenome-wide association studies (PheWASs) to assess pleiotropy and on-target safety, and single-cell RNA sequencing (scRNA-seq) to delineate the cellular context. Molecular docking was used to evaluate the structural druggability of prioritized targets.ResultsMR analysis revealed 15 genes causally associated with gout. Colocalization analysis (PPH4&#x2009;>&#x2009;0.8) prioritized two targets: ZSCAN16 (risk-increasing, OR = 1.04, 95% CI [1.02-1.06]) and TRIM10 (protective, OR = 0.96, 95% CI [0.94-0.98]). Crucially, PheWAS revealed that ZSCAN16 is highly specific to gout, whereas TRIM10 exhibited extensive pleiotropy with hematological and cardiometabolic traits, indicating significant safety risks. Single-cell analysis provided orthogonal validation, demonstrating flare-specific upregulation of ZSCAN16 in cytotoxic T/NK cells. Molecular docking confirmed ZSCAN16 as a structurally druggable target, showing high-affinity binding with known compounds (e.g. digoxin, binding energy&#x2009;=&#x2009;-9.6&#x2005;kcal/mol).ConclusionsOur study identifies ZSCAN16 as a high-potential, druggable therapeutic target for gout, highlighting its genetic influence on specific immune cell activities during acute flares. Conversely, TRIM10 was deprioritized owing to substantial pleiotropic liabilities and poor chemical tractability. These findings suggest that ZSCAN16 could play a crucial role in the pathogenesis of gout and may provide a valuable lead for future drug discovery efforts.

Humans↗

Identifying novel protein biomarkers with cross-psychiatric disorders effects and potential intervention targets: Evidence from proteomic-Mendelian randomization.

Plasma proteins are the potential therapeutic targets for psychiatric disorders due to their important roles in signal transduction. We aimed to explore the plasma protein biomarkers with cross-psychiatric disorders effects. Proteome-wide Mendelian randomization (MR) and colocalization analyses were performed to investigate the potential causal relationship between plasma protein biomarkers and 12 psychiatric disorders and further identify the potential proteins with cross-effects. To assess the directionality and exclude potential reverse causation, Steiger directionality tests and reverse MR analyses were additionally conducted. Then, validation analysis was performed by employing summary data from cross-psychiatric disorder GWAS to validate the cross-psychiatric effects of proteins. Protein-protein interactions were conducted to evaluate the interaction between candidate proteins and druggability assessment was used to prioritize potential drug targets for psychiatric disorders. We identified novel plasma proteins that possessed cross-psychiatric disorder effects, especially BTN2A1 and BTN3A2 associated with major depressive disorder (MDD), schizophrenia (SCZ), and bipolar disorder (BIP); ITIH1, ITIH3, ITIH4 and FES associated with SCZ and BIP, and the cross-effects of these proteins on SCZ and BIP were confirmed by validation analyses. Steiger tests and reverse MR supported causal directionality. Besides, the protein-protein interactions (PPI) analysis indicated cross-effects proteins had significant interaction, especially ITIH1-ITIH3. The druggability assessment prioritized eight proteins, two of which (ITIH3 and NCAM1) has been targeted by antipsychotic drugs. Our findings provided insights into shared biological mechanisms underlying these conditions.

Humans↗

Cross-tissue Mendelian randomization prioritizes RAB27B as a brain-derived candidate protein for postpartum depression.

OBJECTIVE: Postpartum depression (PPD) is one of the most common and debilitating complications of childbirth, yet the candidate proteins linking genetic risk to disease remain poorly defined. Building on recent genome-wide association studies (GWAS), we sought to integrate cross-tissue proteogenomic data to identify candidate proteins for PPD and explore therapeutic opportunities. METHODS: We conducted two-sample Mendelian randomization (MR) using genome-wide significant cis-protein QTLs from brain (n&#x2009;=&#x2009;608 proteins), cerebrospinal fluid (CSF; n&#x2009;=&#x2009;214), and plasma (n&#x2009;=&#x2009;612). PPD summary statistics were obtained from FinnGen R8 (13,657 cases, 236,178 controls) and replicated in an independent GWAS. Phenome-wide association (PheWAS) was used to assess pleiotropy. Potential therapeutic targets were evaluated through DSigDB drug repurposing, molecular docking, and molecular dynamics simulations. RESULTS: Among all proteins tested, RAB27B was the only brain-derived protein surpassing Bonferroni correction (OR&#x2009;=&#x2009;1.60; 95% CI: 1.30-1.96; P&#x2009;=&#x2009;6.6&#x2009;&#xd7;&#x2009;10&#x207b;&#x2076;), whereas no significant proteins were identified in CSF or plasma. This association was replicated in an independent GWAS (OR&#x2009;=&#x2009;1.27; 95% CI: 1.02-1.58; P&#x2009;=&#x2009;0.037). PheWAS identified no pleiotropic associations at genome-wide significance. In silico drug repurposing identified pregnenolone as a candidate ligand with computationally predicted stable binding to RAB27B, providing a starting point for future experimental validation. CONCLUSION: This study provides the first cross-tissue proteogenomic evidence that RAB27B is a brain-derived, reproducible candidate protein genetically associated with PPD. By extending GWAS signals to functional protein-level mechanisms and therapeutic inference, our findings nominate RAB27B and pregnenolone as promising directions for postpartum psychiatric research.

Humans↗

Proteomic pathways mediating low socioeconomic status and cardiovascular events in older adults in CHS and ARIC.

BACKGROUND AND AIMS: Many studies have linked socioeconomic status (SES) and cardiovascular outcomes, yet the biologic mechanisms mediating these associations are only partially understood. The objective of this study was to identify molecular mediators of the association of low SES with coronary heart disease (CHD) and stroke. METHODS: This research was conducted in 2942 Black and White adults in the Cardiovascular Health Study (mean age 76.2 years) and 10,689 Black and White adults in the Atherosclerosis Risk in Communities Study (mean age 60.0 years). We used factor analysis to create a composite measure of low educational attainment, low-income, and blue-collar occupation. Approximately 5000 proteins were measured with an aptamer-based method, and CHD and stroke events were adjudicated. Results were stratified by race, which was conceptualized as a social factor. RESULTS: Low SES was associated with 44 and 262 proteins, in Black and White adults, respectively. No protein met the Bonferroni adjusted threshold for statistically significantly mediation among Black participants. Among White participants, 23 proteins mediated the association between SES adversity and CHD and 5 mediated the association between SES adversity and stroke. The strongest mediating associations for CHD included PTPRS, SCG3, and MMP12. The strongest mediating associations for stroke included NCAN, FAM20B, and APLP1. SPARCL1 and CDCP1 remained the strongest mediators of the association between SES adversity and CHD, after adjusting for potential confounders and traditional cardiovascular risk factors. CONCLUSION: We identified several biomarkers that characterize the biologic risk of SES adversity on CHD and stroke.

Aged↗

Genome-Wide Association Analyses Identify Distinct Genetic Architectures for Extreme Early-Onset and Late-Onset T2D.

AIMS: Type 2 diabetes (T2D) is a heterogeneous disorder with substantial variation in age at onset (AAO). This study aimed to characterize the distinct genetic architectures and biological mechanisms underlying extreme AAO-defined T2D subtypes. MATERIALS AND METHODS: Using 74&#x2009;795 European-ancestry participants from the UK Biobank, we performed genome-wide association studies (GWAS) of relatively early-onset T2D (eoT2D; AAO <&#x2009;55&#x2009;years) and late-onset T2D (loT2D; AAO &#x2265;&#x2009;70&#x2009;years). We investigated subtype-specific genetic loci, SNP-based heritability, genetic correlations, Mendelian randomization (MR)-based relationships, polygenic risk scores (PRS) and phenome-wide association studies (PheWAS). Single-cell transcriptomic data from human pancreatic tissues were further used to evaluate cell-type-specific expression patterns of candidate genes. RESULTS: SNP-based heritability was substantially higher for eoT2D than loT2D (11.2% vs. 6.4%), with eoT2D displaying distinct genetic loci related to &#x3b2;-cell function and insulin regulation, including SLC30A8 and IRS1. By contrast, loT2D showed a comparatively lipid-related genetic profile, featuring APOE-associated signals and expression patterns in immune-related cell populations. Linkage disequilibrium score regression (LDSC) and MR analyses further underscored this divergence: eoT2D exhibited broader genetic overlap with cardiometabolic traits, whereas loT2D showed stronger relationships with traditional metabolic risk factors. Finally, subtype-specific PRSs improved risk discrimination beyond conventional covariates, although their clinical utility warrants further evaluation. CONCLUSIONS: Extreme AAO-defined T2D subtypes exhibit partially distinct genetic architectures, highlighting AAO as an important dimension of T2D heterogeneity and providing a framework for future age-stratified genetic risk assessment.

Type 2 diabetes↗

Identifying potential therapeutic targets for high myopia via a case-control study and Mendelian randomisation analyses of the human blood metabolome.

BACKGROUND: High myopia increases the risk of pathological ocular changes that may lead to irreversible vision loss. Therefore, the identification of potential biomarkers and therapeutic targets for high myopia is essential for early intervention and prevention. METHODS: Summary statistics for 122 blood metabolites were obtained from three genome-wide association studies (GWASs), whereas data on high myopia were derived from a large GWAS conducted with 50,372 participants from the UK Biobank. Mendelian randomisation (MR) analyses were conducted to assess the causal relationships between blood metabolites and high myopia. A real-world case-control study was conducted to validate the causal associations identified in the MR analyses. RESULTS: The systematic MR analysis identified 5 blood metabolites as both biomarkers and potential drug targets for high myopia, including glutamine (odds ratio [OR]: 0.98, 95% confidence interval [CI]: 0.97-1.00), tyrosine (OR: 0.98; 95% CI: 0.97-0.99), degree of unsaturation (OR: 0.98, 95% CI: 0.98-0.99), docosahexaenoic acid (DHA) (OR: 0.99; 95% CI: 0.98-1.00) and isobutyrylcarnitine (OR: 1.09, 95% CI: 1.05-1.13). The case-control study indicated that the levels of glutamine (OR&#x2009;=&#x2009;0.76, 95% CI: 0.58-0.98) and tyrosine (OR&#x2009;=&#x2009;0.72, 95% CI: 0.55-0.94) were significantly associated with a decreased risk of high myopia. CONCLUSIONS: Systematic MR analysis suggested that glutamine, tyrosine, the degree of unsaturation, DHA, and isobutyrylcarnitine may represent promising drug targets for high myopia prevention. Further investigations are needed to validate the therapeutic efficacy and elucidate the underlying mechanisms involved.

Humans↗

Integrative proteogenomic and observational analysis identifies potential biomarkers for latent autoimmune diabetes in adults.

BACKGROUND: Latent autoimmune diabetes in adults (LADA) shares core genetic and immunological features with type 1 diabetes (T1D) but is frequently misdiagnosed as type 2 diabetes (T2D). With few biomarkers for its timely diagnosis and management, this study integrated proteome-wide Mendelian randomisation (MR) and observational clinical analysis to identify potential LADA biomarkers. METHODS: We performed proteome-wide MR using cis-protein quantitative trait loci (cis-pQTLs) for 1,389 plasma proteins from the deCODE study (n&#x2009;=&#x2009;35,559) and genome-wide association study (GWAS) data for LADA (2,634 cases and 5,947 controls, European ancestry). Robustness was enhanced via multiple sensitivity analyses. Pathway enrichment analysis, druggability evaluation, phenome-wide MR, and interaction analyses were performed to investigate the clinical relevance and biological context of candidate proteins. Candidate proteins were further evaluated using enzyme-linked immunosorbent assays in a matched Chinese clinical study (n&#x2009;=&#x2009;241) to assess their discriminative ability for LADA. RESULTS: Proteome-wide MR and colocalisation analyses indicated associations between genetically predicted plasma levels of C-X-C motif chemokine ligand 10 (CXCL10; OR [95% CI] per 1-SD increase in protein levels: 5.49 [1.74,17.32]), serum amyloid A1 (SAA1; 1.28 [1.14,1.45]), and SAA2 (1.22 [1.11,1.34]) with LADA risk. Replication, multi-tissue eQTL, and multivariable MR supported CXCL10's association. Druggability evaluation suggested CXCL10 as a drug target under investigation, and phenome-wide MR of 1,006 diseases and traits indicated no major safety concerns for CXCL10 as a potential biomarker. In the observational clinical study, CXCL10 differentiated LADA from healthy controls (area under the receiver operating characteristic curve [ROC-AUC]: 0.889; precision-recall area under the curve [PR-AUC]: 0.919) and T2D (ROC-AUC: 0.838; PR-AUC: 0.921), with both models showing adequate calibration. CONCLUSIONS: This study suggests that CXCL10 is a putative biomarker associated with LADA, demonstrating discriminative ability to distinguish LADA from T2D in an observational clinical cohort. These findings contribute to understanding the autoimmune molecular aetiology of LADA and support its diagnostic potential in resolving the clinical ambiguity between LADA and T2D.

Humans↗