Stroke genetics informs drug discovery and risk prediction across ancestries

Recurrent Stroke Prediction by Applying a Stroke Polygenic Risk Score in the Japanese Population

BACKGROUND

Recently, various polygenic risk score (PRS)-based methods were developed to improve stroke prediction. However, current PRSs (including cross-ancestry PRS) poorly predict recurrent stroke. Here, we aimed to determine whether the best PRS for Japanese individuals can also predict stroke recurrence in this population by extensively comparing the methods and maximizing the predictive performance for stroke onset.

METHODS

We used data from the disease-oriented BBJ1 (BioBank Japan first cohort; recruited between 2003 and 2007, n=179 938) to derive and optimize the PRSs using a 10-fold cross-validation. We integrated the optimized PRSs for multiple traits, such as vascular risk factors and stroke subtypes to generate a single PRS using the meta-scoring approach (metaGRS). We used an independent BBJ2 (BBJ second cohort; recruited between 2012 and 2017, n=41 929) as a test sample to evaluate the association of the metaGRS with stroke and recurrent stroke. In addition, we analyzed its association stratified by risk factors. We administered 3 distinct tests to consider the potential index event bias.

RESULTS

We analyzed recurrent stroke cases (n=174) and nonrecurrent stroke controls (n=1153) among subjects within the BBJ2. After adjusting for known risk factors, metaGRS was associated with stroke recurrence (adjusted odds ratio per SD, 1.18 [95% CI, 1.00-1.39]; P=0.044), although no significant correlation was observed with the published PRSs. The outcomes derived from these examinations did not provide any significant indication of the influence of index event bias. The high metaGRS group without a history of hypertension had a higher risk of stroke recurrence than that of the low metaGRS group (adjusted odds ratio, 2.24 [95% CI, 1.07-4.66]; P=0.032). There was no association at all in the hypertension group (adjusted odds ratio, 1.21 [95% CI, 0.69-2.13]; P=0.50).

CONCLUSIONS

The metaGRS developed in a Japanese cohort predicted stroke recurrence in an independent cohort of patients. In particular, it predicted an increased risk of recurrence among stroke patients without hypertension. These findings provide clues for additional genetic risk stratification and help in developing personalized strategies for stroke recurrence prevention.

Application of Human Genetics to Prioritize Coagulation Cascade Protein Targets for Ischemic Stroke Prevention

BACKGROUND

While interindividual variations in concentration and function of coagulation cascade proteins are established risk factors for venous thromboembolism (VTE), their associations with arterial ischemic stroke are less well defined.

METHODS

We identified and validated genetic proxies for lifelong, randomized perturbations of coagulation cascade proteins in genome-wide association studies of circulating protein levels (deCODE, n=35 559; UK Biobank, n=46 218) and of VTE risk (81 190 cases and 1 419 671 controls). Study participants were all of European ancestry. We performed 2-sample Mendelian randomization and colocalization analyses to test associations of these genetic proxies with risk of ischemic stroke (62 100 cases and 1 234 808 controls from the GIGASTROKE consortium) and ischemic stroke subtypes, and further contextualized associations with VTE and secondary efficacy and safety outcomes.

RESULTS

We identified genetic proxies for 30 coagulation factors, with cross-trait associations recapitulating canonical coagulation biology. Mendelian randomization and colocalization analyses supported causal associations of genetically proxied levels of 5 proteins with risk of ischemic stroke, with all proteins associating with the cardioembolic stroke subtype: factor XI (odds ratio [OR] of cardioembolic stroke per 1-SD increase, 1.31 [95% CI, 1.19-1.44]; P=3.30×10-8), high-molecular-weight kininogen (OR, 1.19 [95% CI, 1.09-1.30]; P=7.79×10-5), prothrombin (OR, 1.83 [95% CI, 1.31-2.57]; P=4.20×10-4), soluble PROCR (protein C receptor; OR, 0.88 [95% CI, 0.82-0.95]; P=6.19×10-4), and γ' fibrinogen (OR per doubling in VTE risk due to lower γ' fibrinogen levels, 1.44 [95% CI, 1.25-1.66]; P=3.96×10-7). γ' Fibrinogen and prothrombin also associated with large artery atherosclerotic stroke, and no proteins were associated with small vessel stroke risk. By contrast, genetic proxies for several coagulation factors (including proteins C and S and factors V and VII) showed selective associations with VTE.

CONCLUSIONS

These data highlight specific coagulation cascade components implicated in ischemic stroke pathogenesis, while identifying proteins with distinct roles in VTE. These findings may inform development of novel anticoagulants and optimize their use in targeted populations with stroke.

Using Genomics to Develop Personalized Cardiovascular Treatments

Advances in genomic technologies have significantly enhanced our understanding of both monogenic and polygenic etiologies of cardiovascular disease. In this review, we explore how the utilization of genomic information is bringing personalized medicine approaches to the forefront of cardiovascular disease management. We describe how genomic data can resolve diagnostic uncertainty, support cascade screening, and inform treatment strategies. We discuss how genome-wide association studies have identified thousands of genetic variants associated with polygenic cardiovascular diseases, and how integrating these insights into polygenic risk scores can enhance personalized risk prediction beyond traditional clinical algorithms. We detail how pharmacogenomics approaches leverage genotype information to guide drug selection and mitigate adverse events. Finally, we present the paradigm-shifting approach of gene therapy, which holds the promise of being a curative intervention for cardiovascular conditions.

Exploring the shared genetic landscape of diabetes and cardiovascular disease: findings and future implications

Diabetes is a rapidly growing global health concern projected to affect one in eight adults by 2045, which translates to roughly 783 million people. The profound metabolic alterations often present in dysglycaemia significantly increase the risk of cardiovascular complications. While genetic susceptibility plays a crucial role in diabetes and its vascular complications, identifying genes and molecular mechanisms that influence both diseases simultaneously has proven challenging. A key reason for this challenge is the pathophysiological heterogeneity underlying these diseases, with multiple processes contributing to different forms of diabetes and specific cardiovascular complications. This molecular heterogeneity has limited the effectiveness of large-scale genome-wide association studies (GWAS) in identifying shared underlying mechanisms. Additionally, our limited knowledge of the causal genes, cell types and disease-relevant states through which GWAS signals operate has hindered the discovery of common molecular pathways. This review highlights recent advances in genetic epidemiology, including studies of causal associations that have uncovered genetic and molecular factors influencing both dysglycaemia and cardiovascular complications. We explore how disease subtyping approaches can be critical in pinpointing the unique molecular signatures underlying both diabetes and cardiovascular complications. Finally, we address critical research gaps and future opportunities to advance our understanding of both diseases and translate these discoveries into tangible benefits for patient care and population health.

Joint effect of modifiable risk factors and genetic susceptibility on ischaemic stroke

PURPOSE

To investigate the effects of modifiable risk factors and genetic susceptibility on ischaemic stroke (IS).

METHODS

A total of 490365 participants from the UK Biobank, with a 17-year follow-up, were included in this study. Data on 115 modifiable exposures were collected from five domains: early life, environment, lifestyle, socioeconomic status, and physical measures. Additionaly, genetic data were collected. An exposure-wide association analysis was conducted to identify potential risk factors. Risk scores for each domain and genes were calculated. The effect of each domain score on IS and the joint effects among the five domains were analyzed using multi-variate Cox models. The population attributable fraction was estimated to quantize the impact of eliminating unfavorable factors.

RESULTS

Sixty-four of the 115 modifiable exposures were found to be significantly associated with the risk of IS (P < 4.35 × 10-4 for Bonferroni correction). Newly identified factors included maternal smoking and being either overweight or underweight at age 10, which could significantly increase the risk of IS by 4.78 % to 14.74 %, 11.01 % to 23.75 %, and 3.29 % to 12.80 %, respectively. Additionally, exposure to hard water was associated with a decreased risk of IS by 6.96 % to 11.48 % compared to exposure to soft water. The associations varied across domains, with socioeconomic factors accounting for 5.2 % of IS cases, lifestyle accounting for 2.8 %, and physical measures accounting for 2.5 %, representing the top three contributing factors. Overall, it was estimated that 10.6 % to 11.3 % of IS cases could be prevented by eliminating the identified risks.

CONCLUSIONS

Interactions between risk factors and genetic susceptibility elevated the risk of IS. Risk factors from different domains contributed variably to IS, with socioeconomic factors accounting for the largest proportion.

Genetic Risk Scores in Stroke Research and Care

Stroke remains a leading cause of death and disability worldwide. While well-established risk factors play a major role, genetic predisposition is a crucial determinant of stroke susceptibility, with heritability estimates up to 39% for ischemic stroke and 29% for intracerebral hemorrhage. Advances in next-generation sequencing and genome-wide association studies have identified numerous genetic loci associated with stroke risk, paving the way for the development of genetic risk scores. These scores aggregate information from multiple genetic variants to estimate an individual's stroke risk, offering a promising tool for personalized risk stratification that complements traditional clinical models. While GRSs have demonstrated strong predictive potential for primary stroke events in population-based settings, their integration into clinical practice remains limited. Emerging evidence suggests that GRSs could add value in clinical decision-making, for instance, for stratifying ischemic stroke risk in patients with atrial fibrillation, assessing intracerebral hemorrhage risk in anticoagulant users, and predicting vascular risk factor control in stroke survivors. The incorporation of GRSs with multiomics data and machine learning may further refine risk assessment, driving personalized prevention strategies for both primary and secondary stroke preventions. A major challenge is the limited applicability of GRS across diverse populations, as most genome-wide association studies have been conducted in individuals of European ancestry. Addressing this limitation is critical for ensuring equitable and effective implementation of GRSs in clinical settings. As methodologies continue to evolve, integrating GRS into stroke research could significantly enhance risk assessment and support precision medicine approaches tailored to individual patients.

Optimization of multi-ancestry polygenic risk score disease prediction models

Polygenic risk scores (PRS) have ushered in a new era in genetic epidemiology, offering insights into individual predispositions to a wide range of diseases. However, despite recent marked enhancements in predictive power, PRS-based models still need to overcome several hurdles before they can be broadly applied in the clinic. Chiefly, they need to achieve sufficient accuracy, easy interpretability and portability across diverse populations. Leveraging trans-ancestry genome-wide association study (GWAS) meta-analysis, we generated novel, diverse summary statistics for 30 medically-related traits and benchmarked the performance of six existing PRS algorithms using UK Biobank. We built an ensemble model using logistic regression to combine outputs of top-performing algorithms and validated it on the diverse eMERGE and PAGE MEC cohorts. It surpassed current state-of-the-art PRS models, with minimal performance drops in external cohorts, indicating good calibration. To enhance predictive accuracy for clinical application, we incorporated easily-accessible clinical characteristics such as age, gender, ancestry and risk factors, creating disease prediction models intended as prospective diagnostic tests, with easily interpretable positive or negative outcomes. After adding clinical characteristics, 12 out of 30 models surpassed 80% AUC. Further, 25 traits exceeded the diagnostic odds ratio (DOR) of five, and 19 traits exceeded DOR of 10 for all ancestry groups, indicating high predictive value. Our PRS model for coronary artery disease identified 55-80 times more true coronary events than rare pathogenic variant models, reinforcing its clinical potential. The polygenic component modulated the effect of high-risk rare variants, stressing the need to consider all genetic components in clinical settings. These findings show that newly developed PRS-based disease prediction models have sufficient accuracy and portability to warrant consideration of being used in the clinic.

Cardiovascular risk factors modulate the effect of brain imaging-derived phenotypes on ischaemic stroke risk

Studies have shown that cardiovascular risk factors are closely related to the occurrence of stroke, especially ischaemic stroke, as they can lead to changes in brain structure and function. However, the role of cardiovascular risk factors-induced changes in brain structure and function in the development of ischaemic stroke has not been studied. The aim of this study is thus to explore the causal association among cardiovascular risk factors, brain phenotypes and ischaemic stroke by assessing Mendelian randomization. We used univariate Mendelian randomization to sequentially investigate the causal effects of the 12 most common cardiovascular risk factors on brain structure and 3935 brain imaging-derived phenotypes in the development of ischaemic stroke. We also examined the mediating effect of brain structure on blood pressure-induced ischaemic stroke using a multivariable Mendelian randomization test. We tested the reliability of our results using the Steiger test, heterogeneity test, horizontal pleiotropy test and leave-one-out method. We found that 8 of the 12 examined cardiovascular risk factors were associated with 538 brain imaging-derived phenotypes, and 9 of the 12 cardiovascular risk factors were associated with IS. The main cardiovascular risk factors associated with brain imaging-derived phenotypes and ischaemic stroke was blood pressure (systolic and diastolic), which can affect the occurrence of ischaemic stroke through 6 types of brain imaging-derived phenotypes. However, extrapolation of our findings to other ethnic groups is challenging, and the possibility of reverse causality cannot be completely ruled out. This study identifies the role of cardiovascular risk factors, especially blood pressure, in affecting brain structure and ischaemic stroke risk. The findings assist in early risk detection and enhance stroke prevention strategies, also hinting at non-vascular factors' involvement.

A Beneficial Role for Gluteofemoral Adipose Tissue in Cerebrovascular Disease: Causal Pathway and Mediation Analysis

BACKGROUND AND OBJECTIVES

Previous studies have shown that increased body fat is associated with stroke risk, with evidence suggesting that body fat distribution, rather than total body fat, exerts a more prominent role in cerebrovascular risk prediction. In this study, we explore causal associations between body mass index (BMI)-independent adipose tissue distribution profiles and cerebrovascular disease (CVD) risk, aiming to refine the association between body fat distribution and stroke.

METHODS

We selected variants associated with BMI-independent visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue (ASAT), and gluteofemoral adipose tissue (GFAT) volumes in UK Biobank, and performed univariable and multivariable Mendelian randomization (MR) analyses with ischemic stroke (IS) and subtypes (large artery stroke [LAS], cardioembolic stroke [CES], and small vessel stroke [SVS]). We used coronary artery disease (CAD), carotid intima media thickness (cIMT), and MRI-confirmed lacunar stroke as positive controls. We explored the mediatory role of common cardiovascular (systolic blood pressure, diabetes, and low-density lipoprotein), insulin resistance, inflammatory (C-reactive protein), and adipose tissue-specific (adiponectin, leptin) factors by performing 2-step mediation MR analyses. Estimates were expressed per standard deviation increase in adjusted adipose tissue volume.

RESULTS

Genetic predisposition to higher GFAT volume was associated with lower risk of IS (odds ratio [OR] 0.92, 95% CI 0.86-0.98), LAS (OR 0.80, 95% CI 0.66-0.96), and SVS (OR 0.77, 95% CI 0.67-0.88), but not CES, consistent in multivariable analyses. Genetic predisposition to higher GFAT volume was also associated with lower risk of CAD (OR 0.82, 95% CI 0.76-0.88), lacunar stroke (OR 0.78, 95% CI 0.67-0.92), and mean cIMT (β = -0.073, 95% CI -0.114 to -0.031). Associations were largely consistent in sensitivity analyses. No association was observed between genetic predisposition to ASAT or VAT and IS risk. Although common vascular risk factors were the predominant mediators in the GFAT-CVD axis, adiponectin and leptin mediated a proportion of IS and CAD risk (∼15% (1.8%-57%) and ∼4.6% (0.8%-13.5%) mediated by adiponectin, respectively).

DISCUSSION

This study supports a protective role of gluteofemorally distributed fat volume in CVD risk. Although this role is predominantly mediated by common vascular risk factor modification, adipose tissue-specific factors may exert a mediatory effect, suggesting a possible novel target for attenuating adiposity-related CVD risk.

Exploring the genetic intersection between obesity-associated genetic variants and insulin sensitivity indices

Insulin sensitivity (IS) is a key determinant of metabolic health and may share genetic factors with obesity-related traits. Previous large-scale genetic studies have identified variants associated with IS as well as obesity related traits like body mass index (BMI) and waist-to-hip ratio (WHR). Notably, many of these associations are shared across traits, indicating a potential genetic overlap. However, the genetic intersection between IS and obesity-related traits remains underexplored. To explore this gap, we investigated associations between six IS indices, including fasting and post-glucose load measures, and genetic variants linked to BMI and WHR to determine their influence on IS and related cardiometabolic traits. To achieve this, we calculated six IS indices using fasting and oral glucose tolerance test (OGTT) data from 5,007 non-diabetic individuals, grouping them into fasting, OGTT0,120, and OGTT0,30,120 categories. A total of 678 BMI-associated and 265 WHR-associated genetic variants were analysed using linear regression, adjusting for age and sex, with sex-specific analyses for WHR. Analyses were conducted with and without BMI adjustments and corrected for multiple testing (padj). Additionally, we explored the relationship between IS-linked variants and their associations with type 2 diabetes (T2D), coronary artery disease (CAD) and stroke. Among the 678 BMI-associated variants, 100 showed nominal associations (p < 0.05) with at least one IS index; and 20 remained significant after multiple testing correction (padj < 0.05) when not adjusting for BMI. After adjusting for BMI, 70 variants retained nominal associations, and six remained significant (padj < 0.05). In sex-specific analyses of the 265 WHR-associated variants, 12 variants were associated in females when adjusted for BMI, whereas no significant associations were observed in males. Furthermore, BMI- and WHR-associated variants linked to decreased IS, such as those in FTO and VPS13C loci, were also associated with increased T2D and stroke risk, whereas IS-increasing variants, including those in VPS13C and PPARG, were linked to lower T2D and stroke risk, with some, like THADA, showing opposing effects on CAD. This study offers insights into genetic variants that influence both IS and obesity-related traits, revealing BMI- and WHR-associated variants with both positive and negative effects on IS and their potential impact on cardiometabolic health.

Emerging antihypertensive therapies and cardiovascular, kidney, and metabolic outcomes: a Mendelian randomization study

AIMS

Emerging antihypertensive drug classes offer new opportunities to manage hypertension; however, their long-term effects on cardiovascular, kidney, and metabolic (CKM) outcomes remain to be elucidated. This study aims to explore the effects of phosphodiesterase type 5 inhibitors (PDE5i), soluble guanylate cyclase stimulators (sGCs), endothelin receptor antagonists (ERAs), and angiotensinogen inhibitors (AGTis) on a range of CKM outcomes.

METHODS AND RESULTS

Mendelian randomization (MR), summary-based MR (SMR), and colocalization analyses were applied to assess the drug effect on coronary artery disease (CAD), myocardial infarction (MI), ischaemic stroke, atrial fibrillation (AF), heart failure (HF), type 2 diabetes (T2D), and chronic kidney disease (CKD). Genetic association and gene expression summary data were obtained from the largest European-ancestry genome-wide association studies (GWAS) and the genotype-tissue expression version 8 for 29 tissues relevant to the outcomes' pathophysiology.Genetically predicted systolic blood pressure (SBP) reduction was associated with reduced risks of all outcomes. PDE5i was associated with reduced risks of CAD (OR per 10-mmHg decrease in SBP: 0.348[95% confidence interval (CI): 0.199-0.607]) and ischaemic stroke (0.588[0.453-0.763]). sGCs showed protective effects against CAD (0.332[0.236-0.469]), MI (0.238[0.168-0.337]), and CKD (0.55[0.398-0.761]). ERA and AGTi showed protective effects against CAD and ischaemic stroke. SMR and colocalization supported the association of gene expression levels of GUCY1A3 and PDE5A with CAD and MI risk.

CONCLUSION

Our study highlights the potential of PDE5i, sGCs, ERA, and AGTi in reducing cardiovascular and renal risks. These findings underscore the necessity for targeted clinical trials to validate the efficacy and safety of these therapies.

Recent Advances in Immunothrombosis and Thromboinflammation

Inflammation and thrombosis are traditionally considered two separate entities of acute host responses to barrier breaks. While inciting inflammatory responses is a prerequisite to fighting invading pathogens and subsequent restoration of tissue homeostasis, thrombus formation is a crucial step of the hemostatic response to prevent blood loss following vascular injury. Though originally designed to protect the host, excessive induction of either inflammatory signaling or thrombus formation and their reciprocal activation contribute to a plethora of disorders, including cardiovascular, autoimmune, and malignant diseases. In this state-of-the-art review, we summarize recent insights into the intricate interplay of inflammation and thrombosis. We focus on the protective aspects of immunothrombosis as well as evidence of detrimental sequelae of thromboinflammation, specifically regarding recent studies that elucidate its pathophysiology beyond coronavirus disease 2019 (COVID-19). We introduce recently identified molecular aspects of key cellular players like neutrophils, monocytes, and platelets that contribute to both immunothrombosis and thromboinflammation. Further, we describe the underlying mechanisms of activation involving circulating plasma proteins and immune complexes. We then illustrate how these factors skew the inflammatory state toward detrimental thromboinflammation across cardiovascular as well as septic and autoimmune inflammatory diseases. Finally, we discuss how the advent of new technologies and the integration with clinical data have been used to investigate the mechanisms and signaling cascades underlying immunothrombosis and thromboinflammation. This review highlights open questions that will need to be addressed by the field to translate our mechanistic understanding into clinically meaningful therapeutic targeting.

Multiomic Underpinnings of Drug Targets for Intracranial Aneurysm: Evidence From Diversified Mendelian Randomization

AIMS

The absence of pharmaceutics poses challenges in preventing intracranial aneurysm (IA) progression and rupture. This research emphasized identifying drug targets for IA through a druggable genome-wide Mendelian randomization (MR) analysis.

METHODS

A two-sample MR analysis was performed leveraging cis-expression quantitative trait loci in the blood (n = 31,684) and arteries (n = 584) aligned with 5883 druggable genes as exposure and the largest IA summary statistics (n = 7495) as outcome. Bayesian colocalization analysis, plasma cis-protein quantitative trait loci (n = 35,559), and external IA cohorts (FinnGen, n = 2582; Zhou, n = 380) were used for validation. A phenome-wide MR (Phe-MR) incorporating 783 diseases uncovered side effects. Multivariable MR addressed unmeasured pleiotropy.

RESULTS

Five druggable genes in blood and one in the coronary artery showed significant association with IA risk (p-FDR ≤ 0.05). NT5C2, PRCP, and CRMP1 shared a common variant with IA (PPH4 ≥ 0.8). The external validation cohorts confirmed the effects of NT5C2 on IA (FinnGen cohort, Odds Ratio [OR], 0.81, 95% Confidential Interval [95% CI] 95% CI, 0.707-0.930; p = 0.003; Zhou cohort, OR, 0.68, 95% CI, 0.469-0.983; p = 0.041). The genetically predicted protein level of PRCP validated an inverse association with IA risk (OR, 0.734; 95% CI, 0.561-0.959; p = 0.023). The Phe-MR revealed insignificance for NT5C2 or PRCP. Direct causal effects on IA were 0.60 (95% CI, 0.457-0.797; p = 1.36E-05) for PRCP and 0.67 (95% CI, 0.527-0.860; p = 0.002) for NT5C2 after adjusting for IA modifiable risk factors.

CONCLUSIONS

NT5C2 and PRCP were identified as potential drug targets for IA, with effects independent of known modifiable risk factors. Targeting NT5C2 and PRCP appeared exclusively effective and safe.

Morbidity-bridging metabolic pathways: linking early cardiovascular disease risk and depression symptoms using a multi-modal approach

Aims

Prevalence of cardiovascular diseases (CVDs) and depression is rising globally. Their co-occurrence associates with poorer outcomes, potentially due to shared metabolic pathways. This study aimed to identify metabolic pathways linking depression symptoms and CVD risk factors.

Methods and results

Data from the Young Finns Study (YFS, n = 1,599, mean age 37 ± 5, 54% female) served as input for a network (mixed graphical models). Confirmatory analysis through covariate-adjusted regression was done with UK Biobank (UKB, n = 69,513, mean age 63 ± 7, 64% female). Mendelian randomization assessed causality using genome-wide association studies data. The study examined 52 plasma metabolites measured by nuclear magnetic resonance spectroscopy. Outcomes included depression symptoms (BDI in YFS, PHQ-9 in UKB) and CVD risk factors [systolic/diastolic blood pressure, carotid intima-media thickness (cIMT)]. Mendelian randomization inferred causal links between metabolites and depression or (intermediate markers of) CVD. Two bridge metabolites were identified: glucose linked to sleep pattern (P = 0.034); omega-3 fatty acids (FAs) linked to appetite change (P < 0.001); and both connected to cIMT (both P = 0.002). Mendelian randomization suggested glucose as causal in coronary artery disease (CAD) risk, while omega-3 FAs showed potential causal links to CAD, coronary artery calcification, and cIMT.

Conclusion

This study integrated three statistical techniques and identified two metabolic markers (glucose, omega-3 FAs) connecting depression and CVD on a symptom and risk factor level. The associations, established in a relatively young cohort, were replicated in a predominantly middle-aged cohort and emphasize both the generalizability of the findings across different populations and value of symptom-level analysis in depression and CVD comorbidity research.

The relationship between COVID-19 and stroke and its risk factors, a Mendelian randomization analysis

BACKGROUND

It remains unclear about the association between stroke and Coronavirus disease 2019 (COVID-19). Therefore, a Mendelian randomization (MR) analysis was conducted to explore the relationship between them.

METHODS

In this study, the most recent large-scale genome-wide association studies (GWASs) were selected from the publicly available COVID-19 GWAS meta-analysis (Round 7) as the exposure. Data from a recent original stroke GWAS were used as the outcome for the experimental group, while the stroke GWAS data from the IEU GWAS database were used as the validation group. In addition, an MR analysis was conducted to explore the causal relationships of susceptibility, hospitalization, and severity of COVID-19 with stroke and its subtypes. In addition, the results of the experimental and validation groups were integrated to perform a meta-analysis.

RESULTS

The MR analysis results corroborated that there was a positively causal relationship between the hospitalization (OR, 1.11; p = 0.015) (ORmeta, 1.11; p < 0.001), and severity (OR, 1.06; p = 0.043) (ORmeta, 1.07; p = 0.002) of COVID-19 and cardioembolic stroke (CES). This result is supported by the validation group and sensitivity analysis.

CONCLUSION

This study demonstrates for the first time that COVID-19 hospitalization and COVID-19 severity are risk factors for CES.

Proteome-Wide Genetic Study in East Asians and Europeans Identified Multiple Therapeutic Targets for Ischemic Stroke

BACKGROUND

Analyses of genomic and proteomics data in prospective biobank studies in diverse populations may discover novel or repurposing drug targets for stroke.

METHODS

We extracted individual cis-protein quantitative trait locus for 2923 proteins measured using Olink Explore panel from a genome-wide association study in prospective China Kadoorie Biobank and UK Biobank, both established ≈20 years ago. These cis-protein quantitative trait loci were used in ancestry-specific 2-sample Mendelian randomization analyses of ischemic stroke (IS) in East Asians (n=22 664 cases) and Europeans (n=62 100 cases). We further undertook colocalization analyses to examine the shared causal variants of cis-protein quantitative trait locus with stroke, along with various downstream analyses (eg, phenome-wide association study, drug development lookups) to clarify mechanisms of action and druggability.

RESULTS

In Mendelian randomization analyses, the genetically predicted plasma levels of 10 proteins were significantly associated with IS in East Asians (n=2) and Europeans (n=9), with 6 proteins (FGF5 [fibroblast growth factor 5], TMPRSS5 [transmembrane protease serine 5], FURIN, F11 [coagulation factor XI], ALDH2 [aldehyde dehydrogenase 2], and ABO) showing positive and 4 (GRK5 [G protein-coupled receptor kinase 5], KIAA0319 [dyslexia-associated protein KIAA0319], PROCR [endothelial protein C receptor], and MMP12 [macrophage metalloelastase 12]) showing inverse associations, all directionally consistent between East Asians and Europeans. Colocalization analyses provided strong evidence (posterior probabilities for the H4 hypothesis ≥0.7) of shared genetic variants with IS for 9 out of 10 proteins (except ABO). Moreover, 8 proteins were also causally associated, in the expected directions, with systolic blood pressure (positive/inverse: 4/2), low-density lipoprotein cholesterol (1 positive), body mass index (1 inverse), type 2 diabetes (2/1), or atrial fibrillation (3/1). Phenome-wide association study analyses and lookups in knock-out mouse models confirmed their importance for IS or stroke-related traits (eg, hematologic phenotypes). Of these 10 proteins, 1 was not druggable (ABO), 3 had known primary (F11) or potentially repurposed (ALDH2, MMP12) drug targets for stroke, and 6 (PROCR, GRK5, FGF5, FURIN, KIAA0319, and TMPRSS5) had no evidence of any drug targets.

CONCLUSIONS

Proteogenomic investigation in diverse ancestry populations identified the causal relevance of 10 proteins for IS, with several being potentially novel or repurposed targets that could be prioritized for further investigation.

Causal Relevance of Lp(a) for Coronary Heart Disease and Stroke Types in East Asian and European Ancestry Populations: A Mendelian Randomization Study

BACKGROUND

Elevated plasma levels of Lp(a) [lipoprotein(a)] are a causal risk factor for coronary heart disease and stroke in European individuals, but the causal relevance of Lp(a) for different stroke types and in East Asian individuals with different Lp(a) genetic architecture is uncertain.

METHODS

We measured plasma levels of Lp(a) in a nested case-control study of 18 174 adults (mean [SD] age, 57 [10] years; 49% female) in the China Kadoorie Biobank (CKB) and performed a genome-wide association analysis to identify genetic variants affecting Lp(a) levels, with replication in ancestry-specific subsets in UK Biobank. We further performed 2-sample Mendelian randomization analyses, associating ancestry-specific Lp(a)-associated instrumental variants derived from CKB or from published data in European individuals with risk of myocardial infarction (n=17 091), ischemic stroke (IS [n=29 233]) and its subtypes, or intracerebral hemorrhage (n=5845) in East Asian and European individuals using available data from CKB and genome-wide association analysis consortia.

RESULTS

In CKB observational analyses, plasma levels of Lp(a) were log-linearly and positively associated with higher risks of myocardial infarction and IS, but not with ICH. In genome-wide association analysis, we identified 29 single nucleotide polymorphisms independently associated with Lp(a) that together explained 33% of variance in Lp(a) in Chinese individuals. In UK Biobank, the lead Chinese variants identified in CKB were replicated in 1260 Chinese individuals, but explained only 10% of variance in Lp(a) in European individuals. In Mendelian randomization analyses, however, there were highly concordant effects of Lp(a) across both ancestries for all cardiovascular disease outcomes examined. In combined analyses of both ancestries, the proportional reductions in risk per 100 nmol/L lower genetically predicted Lp(a) levels for myocardial infarction were 3-fold greater than for total IS (rate ratio, 0.78 [95% CI, 0.76-0.81] versus 0.94 [0.92-0.96]), but were similar to those for large-artery IS (0.80 [0.73-0.87]; n=8134). There were weaker associations with cardioembolic IS (0.92 [95% CI, 0.86-0.98]; n=11 730), and no association with small-vessel IS (0.99 [0.91-1.07]; n=12 343) or with intracerebral hemorrhage (1.08 [0.96-1.21]; n=5845).

CONCLUSIONS

The effects of Lp(a) on risk of myocardial infarction and large-artery IS were comparable in East Asian and European individuals, suggesting that people with either ancestry could expect comparable proportional benefits for equivalent reductions in Lp(a), but there was little effect on other stroke types.

Evaluation of Machine Learning and Traditional Statistical Models to Assess the Value of Stroke Genetic Liability for Prediction of Risk of Stroke Within the UK Biobank

Background and Objective: Stroke is one of the leading causes of mortality and long-term disability in adults over 18 years of age globally, and its increasing incidence has become a global public health concern. Accurate stroke prediction is highly valuable for early intervention and treatment. There is a scarcity of studies evaluating the prediction value of genetic liability in the prediction of the risk of stroke. Materials and Methods: Our study involved 243,339 participants of European ancestry from the UK Biobank. We created stroke genetic liability using data from MEGASTROKE genome-wide association studies (GWASs). In our study, we built four predictive models with and without stroke genetic liability in the training set, namely a Cox proportional hazard (Coxph) model, gradient boosting model (GBM), decision tree (DT), and random forest (RF), to estimate time-to-event risk for stroke. We then assessed their performances in the testing set. Results: Each unit (standard deviation) increase in genetic liability increases the risk of incident stroke by 7% (HR = 1.07, 95% CI = 1.02, 1.12, p-value = 0.0030). The risk of stroke was greater in the higher genetic liability group, demonstrated by a 14% increased risk (HR = 1.14, 95% CI = 1.02, 1.27, p-value = 0.02) compared with the low genetic liability group. The Coxph model including genetic liability was the best-performing model for stroke prediction achieving an AUC of 69.54 (95% CI = 67.40, 71.68), NRI of 0.202 (95% CI = 0.12, 0.28; p-value = 0.000) and IDI of 1.0 × 10-4 (95% CI = 0.000, 3.0 × 10-4; p-value = 0.13) compared with the Cox model without genetic liability. Conclusions: Incorporating genetic liability in prediction models slightly improved prediction models of stroke beyond conventional risk factors.

Evidence to shared genetic correlation of ischemic stroke and intracerebral hemorrhage and cardiovascular related traits

BACKGROUND

Previous studies have demonstrated the genetic basis of stroke and also revealed their genetic correlation with some cardiovascular related diseases or traits at the entire genome, which, however, would not give the answer which regions may mainly account for the genetic overlap. This study aims to identify specific genetic loci that contribute to the shared genetic basis between ischemic stroke subtypes and common cardiovascular traits.

METHODS

We used Local Analysis of [co]Variant Annotation (LAVA), a recent developed local genetic correlation method, to perform a system local genetic correlation analysis on GWAS summary data of two major subtypes of stroke, including any ischemic stroke (AIS) and intracerebral hemorrhage (ICH), and ten common cardiovascular related diseases or traits (CRTs). We further used colocalization analysis to explore potential shared causal genes in loci with significant local genetic correlation. In addition, we also performed Transcriptome-wide association (TWAS) analysis and fine-mapping for each phenotype to functionally annotate significant loci.

RESULTS

LAVA analysis identified a total of 3 significant local genetic correlations (Bonferroni-adjusted P <  0.05) across 3 chromosomes between AIS and systolic blood pressure (SBP), AIS and hypertension (HT), and ICH and body mass index (BMI), among which locus 7.24 explicated to harbor a shared causal variant for AIS and SBP. TWIST1 in locus 7.24 was defined to be nominally associated with SBP, but not for AIS. Fine-mapping analysis also only identified TWIST1 a credible causal gene for BMI.

CONCLUSIONS

Our study revealed the local genetic correlations between two stroke subtypes and ten common CRTs. Gene-level analyses indicated that biological explanations underlying these identified local genetic correlations may existed elsewhere beyond a common pattern of genetic-gene expression regulation.

Dissecting the Genetic Architecture of Intracranial Aneurysms

BACKGROUND

The genetic risk of intracranial aneurysm (IA) development has been ascribed to the genetic risk of smoking exposure and hypertension. The relationship of IA to other cardiovascular traits and the contribution of IA risk loci to aberrant gene programs within cerebrovascular cell types remains unclear.

METHODS

We performed a genome-wide association study in the Million Veteran Program and Finnish cohort study testing association of roughly 25 million DNA variants with unruptured IA (4694 cases and 877 091 controls) in individuals of European, African, and Hispanic ancestries. Meta-analysis with publicly available summary statistics generated a final cohort of 15 438 cases and 1 183 973 controls. We constructed a cerebrovascular single-nuclear RNA sequencing data set and integrated IA summary statistics to prioritize candidate causal cell types. We constructed a polygenic risk score to identify patients at risk of developing IA.

RESULTS

We identified 5 novel associations with IA, increasing the number of known susceptibility loci to 22. At these susceptibility loci, we prioritized 17 candidate causal genes. We found a significant positive genetic correlation of IA with coronary artery disease and abdominal aortic aneurysm. Integration of an IA gene set with cerebrovascular single-nuclear RNA sequencing data revealed a significant association with pericytes and smooth muscle cells. Finally, a polygenic risk score was significantly associated with IA across European (odds ratio, 1.87 [95% CI, 1.61-2.17]; P=8.8×10-17), African (odds ratio, 1.62 [95% CI, 1.19-2.15]; P=1.2×10-3), and Hispanic (odds ratio, 2.28 [95% CI, 1.47-3.38]; P=1.0×10-4) ancestries.

CONCLUSIONS

Here, we identify 5 novel loci associated with IA. Integration of summary statistics with cerebrovascular single-nuclear RNA sequencing reveals an association of cell types involved in matrix production. We validated a polygenic risk score that predicts IA, controlling for demographic variables including smoking status and blood pressure. Our findings suggest that a deficit in matrix production may drive IA pathogenesis independent of hypertension and smoking.

Closed-loop rehabilitation of upper-limb dyskinesia after stroke: from natural motion to neuronal microfluidics

This review proposes an innovative closed-loop rehabilitation strategy that integrates multiple subdomains of stroke science to address the global challenge of upper-limb dyskinesia post-stroke. Despite advancements in neural remodeling and rehabilitation research, the compartmentalization of subdomains has limited the effectiveness of current rehabilitation strategies. Our approach unites key areas-including the post-stroke brain, upper-limb rehabilitation robotics, motion sensing, metrics, neural microfluidics, and neuroelectronics-into a cohesive framework designed to enhance upper-limb motion rehabilitation outcomes. By leveraging cutting-edge technologies such as lightweight rehabilitation robotics, advanced motion sensing, and neural microfluidic models, this strategy enables real-time monitoring, adaptive interventions, and personalized rehabilitation plans. Furthermore, we explore the potential of closed-loop systems to drive neural plasticity and functional recovery, offering a transformative perspective on stroke rehabilitation. Finally, we discuss future directions, emphasizing the integration of emerging technologies and interdisciplinary collaboration to advance the field. This review highlights the promise of closed-loop strategies in achieving unprecedented integration of subdomains and improving post-stroke upper-limb rehabilitation outcomes.

A Mendelian randomization analysis of cardiac MRI measurements as surrogate outcomes for heart failure and atrial fibrillation

BACKGROUND

Drug development and disease prevention of heart failure (HF) and atrial fibrillation (AF) are impeded by a lack of robust early-stage surrogates. We determined to what extent cardiac magnetic resonance (CMR) measurements act as surrogates for the development of HF or AF.

METHODS

Genetic data were sourced on the association with 21 atrial and ventricular CMR measurements. Mendelian randomization was used to determine CMR associations with AF, HF, non-ischaemic cardiomyopathy (NICM), and dilated cardiomyopathy (DCM), noting that the definition of NICM includes DCM as a subset. Additionally, for the CMR surrogates of AF and HF, we explored their association with non-cardiac traits potentially influenced by cardiac disease liability.

RESULTS

In total we find that 7 CMR measures (biventricular ejection fraction (EF) and end-systolic volume (ESV), as well as LV systolic volume (SV), end-diastolic volume (EDV), and mass to volume ratio (MVR)) associate with the development of HF, 5 with the development of NICM (biventricular EDV and ESV, LV-EF), 7 with DCM (biventricular EF, ESV, EDV, and LV end-diastolic mass (EDM), and 3 associate with AF (LV-ESV, RV-EF, RV-ESV). Higher EF of both ventricles associate with lower risk of HF and DCM, with biventricular ESV associating with all four cardiac outcomes. Higher values of biventricular EDV associate with lower risk of HF, and DCM. Exploring the associations of these CMR cardiac disease surrogates with non-cardiac traits confirms a strong link with diastolic blood pressure, as well as more specific associations with lung function (LV-ESV), HbA1c (LV-EDM), and type 2 diabetes (LV-SV).

CONCLUSIONS

The current paper identifies key CMR measurements that may act as surrogate endpoints for the development of HF (including NICM and DCM) or AF.

Clinical utility and implementation of polygenic risk scores for predicting cardiovascular disease: A clinical consensus statement of the ESC Council on Cardiovascular Genomics, the ESC Cardiovascular Risk Collaboration, and the European Association of Preventive Cardiology

Genome-wide association studies have revealed hundreds of genetic variants associated with cardiovascular diseases (CVD). Polygenic risk scores (PRS) can capture this information in a single metric and hold promise for use in CVD risk prediction. Importantly, PRS information can reflect the causally mediated risk to which the individual is exposed throughout life. Although European Society of Cardiology guidelines do not currently advocate their use in routine clinical practice, PRS are commercially available and increasingly sought by clinicians, health systems, and members of the public to inform personalized health care decision-making. This clinical consensus statement provides an overview of the scientific basis of PRS and evidence to date on their role in CVD risk prediction for the purposes of disease prevention. It provides the reader with a summary of the opportunities and challenges for implementation and identifies current gaps in supporting evidence. The document also lays out a potential roadmap by which the scientific and clinical community can navigate any future transition of PRS into routine clinical care. Finally, clinical scenarios are presented where information from PRS may hold most value and discuss organizational frameworks to enable responsible use of PRS testing while more evidence is being generated by clinical studies.

The Estonian Biobank's journey from biobanking to personalized medicine

Large biobanks have set a new standard for research and innovation in human genomics and implementation of personalized medicine. The Estonian Biobank was founded a quarter of a century ago, and its biological specimens, clinical, health, omics, and lifestyle data have been included in over 800 publications to date. What makes the biobank unique internationally is its translational focus, with active efforts to conduct clinical studies based on genetic findings, and to explore the effects of return of results on participants. In this review, we provide an overview of the Estonian Biobank, highlight its strengths for studying the effects of genetic variation and quantitative phenotypes on health-related traits, development of methods and frameworks for bringing genomics into the clinic, and its role as a driving force for implementing personalized medicine on a national level and beyond.

Metabolic Factors Mediate the Causal Effect of Physical Activity and Sedentary Behavior on Stroke and Its Subtypes: Evidence from Mendelian Randomization Study

In observational studies, physical activity and sedentary behavior are associated with the risk of stroke (overall and stroke subtypes). However, whether it is causal relevance remains to be established. Given that exercise habits can be an intervention towards preventing strokes, we assessed the causality of behavioral habits with stroke and its subtypes using Mendelian randomization (MR) approaches. Stroke was analyzed as all-cause ischemic stroke (IS), three IS subtypes including large artery stroke, small vessel stroke and cardioembolic stroke, and intracerebral hemorrhage (ICH). Univariable MR analyses revealed an association between genetically predicted leisure screen time and higher overall IS risk (odds ratio (OR), 1.12; 95% confidence interval (CI), 1.06 to 1.19; P = 1.65 × 10-4). A protective association was also reported between genetically linked moderate-to-vigorous intensity physical activity and the risk of small vessel stroke (OR, 0.52; 95% CI, 0.32 to 0.84; P = 0.008). Further reverse analyses found no causal effect of IS on leisure screen time and small vessel stroke on moderate-to-vigorous intensity physical activity. We also studied the mediating role of metabolic traits including obesity, blood lipids, blood glucose, and blood pressure via two-step MR. It was found in mediation analysis that BMI partly mediated the causal relationship between leisure screen time and all-cause IS; the mediated proportion was 26.1% (95% CI: 18.1 to 35.0%). We found evidence that a sedentary lifestyle is associated with a higher risk of overall IS, and BMI plays a mediating role in the causal pathway. Our findings provide genetic evidence for the point that active lifestyles may be an effective prevention strategy for IS.

(Apo)Lipoprotein Profiling with Multi-Omics Analysis Identified Medium-HDL-Targeting PSRC1 with Therapeutic Potential for Coronary Artery Disease

Identification of (apo)lipoprotein subclasses causally underpinning atherosclerosis may lead to identification of novel drug targets for treatment of atherosclerotic cardiovascular disease (ASCVD). In this study, observational and genetic associations between (apo)lipoprotein profile and carotid intima-media thickness-assessed atherosclerosis, and risks of coronary artery disease (CAD) and ischemic stroke (IS) are assessed, using data from the UK Biobank study, with further exploration of potential drug target for these two ASCVD subtypes through multi-omics analysis integrating genetic, transcriptomic, and proteomic data. Cholesteryl ester content in medium high-density lipoprotein causally protective of atherosclerosis is identified, plus a target gene, PSRC1, with therapeutic potential for CAD, but not IS, supported by consistent evidence from multi-omics layers of data, which also reveals that such therapeutic potential may be through downregulation of circulating proteins including TRP1, GRNs, and Pla2g12b, and upregulation of Neo1. The results provide strong evidence as well as mechanistic clues of PSRC1's therapeutic potential for CAD.

Reassessing the Association of Sedentary Behavior and Physical Activity with Ischemic Stroke: A Mendelian Randomization Study

PURPOSE

Findings from previous Mendelian randomization (MR) studies disagreed with the current scientific consensus regarding the role of physical activity (PA) and sedentary behavior in ischemic stroke (IS). We reassessed these associations with a focus on etiological subtypes of IS and the potential mediating roles of cardiometabolic traits and brain imaging-derived phenotypes (IDPs).

METHODS

We performed MR analyses using summary statistics from genome-wide association studies of sedentary behavior and PA ( n = 88,411 ~ 608,595), cardiometabolic traits ( n = 393,193 ~ 694,649), brain IDPs ( n = 33,224), and the latest IS data (62,100 cases and 1,234,808 controls). Inverse-variance weighted regression was used as the primary method, complemented by several sensitivity analyses. A two-step MR approach was employed to assess the mediating effects of cardiometabolic traits and brain IDPs.

RESULTS

Genetic liability to leisure-time moderate-to-vigorous PA (MVPA) and higher overall PA (OPA) were associated with reduced risks of IS and small vessel stroke (Benjamini-Hochberg adjusted P < 0.05). Suggestive associations were observed between longer leisure-screen time and higher IS risk and between higher OPA and lower cardioembolic stroke risk ( P < 0.05). The isotropic volume fraction in the anterior limb of the left internal capsule, as well as some cardiometabolic metrics, partially mediated these associations. There was no evidence for causal effects of overall MVPA, overall light-intensity PA, or overall sedentary duration on IS.

CONCLUSIONS

Longer leisure screen time, less OPA, and not engaging in MVPA during leisure time were associated with higher risk of IS. The associations between PA and IS depended on different subtypes and were mediated by changes in anterior limb of the left internal capsule and cardiometabolic biomarkers.

Adult Height, Cardiovascular Disease, and the Underlying Mechanism: A Comprehensive Epidemiological and Genetic Analysis

BACKGROUND

Adult height measures the complete growth of an individual and influences the development of cardiovascular disease (CVD). Despite recent within-sibling studies that have suggested minimal effects from environmental confounders, biological mechanisms underlying the height-CVD relationship remain elusive.

METHODS

Leveraging the large-scale UK Biobank data set and summary statistics from the latest genome-wide association studies, we reevaluated the effect of height on 8 major CVD subtypes. Phenotypic associations were determined using Cox proportional hazard analysis. Putative causal relationships were assessed using univariable Mendelian randomization. Mediation analysis and 2-step Mendelian randomization were further performed to investigate the mediation effect of 15 common cardiometabolic or pulmonary risk factors.

RESULTS

Height was consistently associated with a decreased risk of coronary artery disease (CAD), confirmed in epidemiological (hazard ratio, 0.90; 95% confidence interval [CI], 0.88-0.91) and genetic (odds ratio, 0.89, 95% CI, 0.86-0.92) analysis. Forced vital capacity was identified as the most significant mediator for the height-CAD relationship in epidemiological (proportion-mediated, 65.6%; 95% CI, 53.1%-78.0%) and genetic (proportion-mediated, 46.2%; 95% CI, 5.0%-87.5%) analysis. Notably, obesity, and blood pressure, lipid, and C-reactive protein levels also exhibited significant mediatory effects. Despite a consistent risk effect of height on atrial fibrillation and venous thromboembolism, no promising mediator was identified.

CONCLUSIONS

Our study confirms the health effects of height on CAD, atrial fibrillation, and venous thromboembolism and emphasizes forced vital capacity as the primary pathway that links height to CAD. Importantly, it indicates that the CAD risk associated with nonmodifiable height could be mitigated through enhanced lung function and cardiometabolic conditions.

Genetic Susceptibility to Type 2 Diabetes, Television Viewing, and Atherosclerotic Cardiovascular Disease Risk

BACKGROUND

Type 2 diabetes (T2D) is a major risk factor for atherosclerotic cardiovascular disease (ASCVD). This study examined the interplay between watching television and T2D genetic risk for risk of ASCVD.

METHODS

We included 346 916 White British individuals from UK Biobank. A weighted polygenic risk score for T2D was calculated on the basis of 138 genetic variants associated with T2D. Time spent watching television was self-reported and categorized into 2 groups: ≤1 h/d and ≥2 h/d. Over a median 13.8-year follow-up, 21 265 incident ASCVD events were identified. Models using Cox regression with age as the underlying time scale adjusted for potential confounders (demographic, anthropometric, lifestyle factors, and medication use) were fit.

RESULTS

Compared with watching television for ≤1 h/d, watching ≥2 h/d was associated with 12% (95% CI, 1.07-1.16) higher hazards of ASCVD, independently of T2D genetic risk. Joint analyses (with low T2D genetic risk and ≤1 h/d of television viewing as reference) indicated that medium and high T2D genetic risk was not associated with higher hazards of ASCVD as long as television viewing was ≤1 h/d. The P values for multiplicative and additive interactions between T2D genetic risk and television viewing were 0.050 and 0.038, respectively. The 10-year absolute risk of ASCVD was lower for high T2D genetic risk combined with ≤1 h/d of television viewing (2.13%) than for low T2D genetic risk combined with ≥2 h/d of television viewing (2.46%).

CONCLUSIONS

Future clinical trials of lifestyle-modification interventions targeting specific types of screen-based sedentary activities could be implemented to individuals at high genetic risk of T2D for primary prevention of ASCVD.

A cross-tissue transcriptome-wide association study identifies new key genes in ischemic stroke

BACKGROUND

Ischemic stroke (IS) is an important disease causing death and disability worldwide, and further investigation of IS-related genes through genome-wide association study (GWAS) data is valuable.

METHODS

The study included GWAS data from 62,100 IS patients of European origin and 1,234,808 controls in a cross-tissue transcriptome association study (TWAS). A joint analysis was first performed by the Unified Test for Molecular Markers (UTMOST) and FUSION methods. The results of the joint analysis were also validated by fine-mapping through FOCUS. Mendelian randomisation analysis was performed to determine whether the obtained genes were causally related to IS. Genome Annotated Multiple Marker Analysis (MAGMA) explored which biological functions the genes associated with IS. We used Coloc to co-localise GWAS and eQTL of the genes. We also biologically validated the results by Western blotting and immunofluorescence staining in the middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model.

RESULTS

Four TWAS methods identified only one new susceptibility gene (USP38) associated with IS risk. Mendelian randomization and colocalization analysis found that USP38 may be protective against IS development. Functional enrichment analysis indicated IS-related genes were mainly associated with the intrinsic fibrinogen activation, acute myocardial infarction, exogenous fibrinogen activation, coagulation cascade response, TNF signalling pathway and GRB2 signalling pathway. Western blotting and immunofluorescence staining demonstrated a reduction in USP38 expression in MCAO/R mice.

CONCLUSION

Our research indicates that USP38 is an essential gene related to IS, with its expression strongly connected with IS risk, thus providing new perspectives on the genetic framework of IS.

Molecular heterogeneity in human stroke - What can we learn from the peripheral blood transcriptome?

Stroke is a multifaceted disease with genetic and environmental components like diet and lifestyle. The central nervous and immune systems display complex interactions, with the peripheral immune response participating in brain injury and repair mechanisms following stroke. The bidirectional communication between the injured brain and peripheral blood presents an opportunity to investigate the molecular changes in the latter. There is substantial heterogeneity in stroke pathogenesis, pathophysiology, comorbidities, and response to treatment and outcome. This is captured and underscored by heterogeneity in the peripheral blood transcriptome. The current review highlights the role of the human peripheral blood transcriptome architecture for molecular phenotyping of different stroke etiologies and comorbidities, and for identifying underlying molecular correlates with clinically important variables and outcomes. Specific transcriptome features can potentially provide targets for clinical translation and for prioritizing genes and pathways for evaluation in experimental models. We also propose an approach to study the patient-specific transcriptional architecture and uncover the combinatorial heterogeneity in altered pathways in stroke patients that can also guide the search for treatment and prevention targets. Deciphering the molecular heterogeneity of stroke in a tissue that can be easily accessed and monitored, such as peripheral blood, may improve clinical trial success.

A cis-regulatory element controls expression of histone deacetylase 9 to fine-tune inflammasome-dependent chronic inflammation in atherosclerosis

Common genetic variants in a conserved cis-regulatory element (CRE) at histone deacetylase (HDAC)9 are a major risk factor for cardiovascular disease, including stroke and coronary artery disease. Given the consistency of this association and its proinflammatory properties, we examined the mechanisms whereby HDAC9 regulates vascular inflammation. HDAC9 bound and mediated deacetylation of NLRP3 in the NACHT and LRR domains leading to inflammasome activation and lytic cell death. Targeted deletion of the critical CRE in mice increased Hdac9 expression in myeloid cells to exacerbate inflammasome-dependent chronic inflammation. In human carotid endarterectomy samples, increased HDAC9 expression was associated with atheroprogression and clinical plaque instability. Incorporation of TMP195, a class IIa HDAC inhibitor, into lipoprotein-based nanoparticles to target HDAC9 at the site of myeloid-driven vascular inflammation stabilized atherosclerotic plaques, implying a lower risk of plaque rupture and cardiovascular events. Our findings link HDAC9 to atherogenic inflammation and provide a paradigm for anti-inflammatory therapeutics for atherosclerosis.

Plasma Proteomic Assessment of Calcific Aortic Valve Disease in Older Adults

BACKGROUND

Calcific aortic valve disease (CAVD), and ensuing severe aortic stenosis (AS), is the foremost valvular disorder of aging, yet preventive therapies are lacking. A better understanding of the molecular underpinnings of aortic valve calcification (AVC) is necessary to develop pharmacologic interventions.

METHODS AND RESULTS

We undertook large-scale plasma proteomics in a cohort study of adults ≥65 years old, the CHS (Cardiovascular Health Study), to identify individual proteins associated with echocardiographic AVC and incident moderate/severe AS. Proteomics measurements were performed with the aptamer-based SomaLogic platform of ~5000 proteins. Significant proteins were validated in a second cohort, the AGES-RS (Age, Gene/Environment Susceptibility-Reykjavik Study), which assessed AVC and AS by computed tomography. The potential causal associations of replicated proteins were tested in 2-sample Mendelian randomization using identified cis protein quantitative trait loci in consortia having computed tomography-quantified AVC or AS as outcomes. Six proteins showed Bonferroni-corrected significant relationships with AVC in CHS. Three of these, CXCL-12 (C-X-C chemokine ligand 12), KLKB1 (kallikrein), and leptin, replicated in AGES-RS, of which the former 2 are novel. Only 1 protein, CXCL6, which showed a near-significant association with AS in the replication cohort, was significantly (positively) associated with incident AS. Mendelian randomization analysis was conducted for KLKB1, CXCL12, and CXCL6, which supported a causal relationship for higher KLKB1 with lower AVC (beta=-0.25, P=0.009).

CONCLUSIONS

This study of older adults newly identified and largely replicated associations of 3 circulating proteins with calcific aortic valve disease, of which the relationship of plasma KLKB1 may have a causal basis. Additional investigation is necessary to determine if KLKB1 could be harnessed for calcific aortic valve disease therapeutics.

Monogenic causes of cerebral small vessel disease- models for vascular cognitive impairment and dementia?

PURPOSE OF REVIEW

Recent advancements in molecular biomarkers and therapeutic options for Alzheimer's disease have brought into focus the need for greater progress in the second most common cause of dementia, vascular cognitive impairment and dementia (VCID). We examine how the study of monogenic causes of VCID has contributed to the understanding of its pathophysiology and potential biomarker and treatment research.

RECENT FINDINGS

It is widely accepted that conditions which disrupt the cerebral small vessels contribute to vascular pathologies including stroke and cerebral microbleeds, ultimately leading to vascular cognitive impairment and dementia. Among these conditions are a range of monogenic small vessel diseases (SVDs) such as CADASIL, CARASIL, Fabry disease and COL4A-related disorders.

SUMMARY

This review indicates the importance of furthering research into monogenic SVDs in order to gain insight into the pathomechanisms of VCID more broadly. Monogenic conditions are easier to model than sporadic VCID and can serve as a guide for identifying biomarkers for diagnosis, monitoring and intervention outcomes.

The Multifaceted Roles of BACH1 in Disease: Implications for Biological Functions and Therapeutic Applications

BTB domain and CNC homolog 1 (BACH1) belongs to the family of basic leucine zipper proteins and is expressed in most mammalian tissues. It can regulate its own expression and play a role in transcriptionally activating or inhibiting downstream target genes. It has a crucial role in various biological processes, such as oxidative stress, cell cycle, heme homeostasis, and immune regulation. Recent research highlights BACH1's significant regulatory roles in a series of conditions, including stem cell pluripotency maintenance and differentiation, growth, senescence, and apoptosis. BACH1 is closely associated with cardiovascular diseases and contributes to angiogenesis, atherosclerosis, restenosis, pathological cardiac hypertrophy, myocardial infarction, and ischemia/reperfusion (I/R) injury. BACH1 promotes tumor cell proliferation and metastasis by altering tumor metabolism and the epithelial-mesenchymal transition phenotype. Moreover, BACH1 appears to show an adverse role in diseases such as neurodegenerative diseases, gastrointestinal disorders, leukemia, pulmonary fibrosis, and skin diseases. Inhibiting BACH1 may be beneficial for treating these diseases. This review summarizes the role of BACH1 and its regulatory mechanism in different cell types and diseases, proposing that precise targeted intervention of BACH1 may provide new strategies for human disease prevention and treatment.

Multi-Cohort Analysis Reveals Genetic Predispositions to Clonal Hematopoiesis as Mutation-Specific Risk Factors for Stroke

Recent observational studies have found an association between Clonal Hematopoesis (CH) and strokes but with incomplete results. This study aims to comprehensively characterize mutation-specific effects of CH on ischemic and hemorrhagic stroke subtypes and 90-day functional outcomes through publicly available genome-wide association study (GWAS) cohorts and Mendelian Randomization. TET2 is associated with an increased risk of overall stroke (OR = 1.06, P = 0.02), ischemic stroke (OR = 1.05, P = 0.03), transient ischemic attack (OR = 1.07, P = 0.01) and small vessel stroke (OR = 1.29, P = 0.01), as well as adverse 90-day modified Rankin scale (mRS ≥ 3) before (OR = 1.34, P = 0.005) and after adjusted for age, sex, and stroke severity (OR = 1.30, P = 0.02). While the presence of any CH mutation is associated with intracerebral hemorrhage (ICH) (OR = 1.21, P = 0.02), specific mutations, SRSF2 and ASXL1 are protective against ICH (OR = 0.9, P = 0.04) and nontraumatic subarachnoid hemorrhage (OR = 0.92, P = 0.03), respectively. In conclusion, the study provided genetic evidence that TET2 is strongly associated with an increased risk of ischemic stroke and poor functional recovery. Future studies clarifying the relationship between CH and hemorrhagic stroke subtypes are needed.

Genetic Analysis of Retinal Cell Types in Neuropsychiatric Disorders

Importance

As an accessible part of the central nervous system, the retina provides a unique window to study pathophysiological mechanisms of brain disorders in humans. Imaging and electrophysiological studies have revealed retinal alterations across several neuropsychiatric and neurological disorders, but it remains largely unclear which specific cell types and biological mechanisms are involved.

Objective

To determine whether specific retinal cell types are affected by genomic risk for neuropsychiatric and neurological disorders and to explore the mechanisms through which genomic risk converges in these cell types.

Design, Setting, and Participants

This genetic association study combined findings from genome-wide association studies in schizophrenia, bipolar disorder, major depressive disorder, multiple sclerosis, Parkinson disease, Alzheimer disease, and stroke with retinal single-cell transcriptomic datasets from humans, macaques, and mice. To identify susceptible cell types, Multi-Marker Analysis of Genomic Annotation (MAGMA) cell-type enrichment analyses were applied and subsequent pathway analyses performed. The cellular top hits were translated to the structural level using retinal optical coherence tomography (acquired between 2009 and 2010) and genotyping data in the large population-based UK Biobank cohort study. Data analysis was conducted between 2022 and 2024.

Main Outcomes and Measures

Cell type-specific enrichment of genetic risk loading for neuropsychiatric and neurological disorder traits in the gene expression profiles of retinal cells.

Results

Expression profiles of amacrine cells (interneurons within the retina) were robustly enriched in schizophrenia genetic risk across mammalian species and in different developmental stages. This enrichment was primarily driven by genes involved in synapse biology. Moreover, expression profiles of retinal immune cell populations were enriched in multiple sclerosis genetic risk. No consistent cell-type associations were found for bipolar disorder, major depressive disorder, Parkinson disease, Alzheimer disease, or stroke. On the structural level, higher polygenic risk for schizophrenia was associated with thinning of the ganglion cell inner plexiform layer, which contains dendrites and synaptic connections of amacrine cells (B, -0.09; 95% CI, -0.16 to -0.03; P = .007; n = 36 349; mean [SD] age, 57.50 [8.00] years; 19 859 female [54.63%]). Higher polygenic risk for multiple sclerosis was associated with increased thickness of the retinal nerve fiber layer (B, 0.06; 95% CI, 0.02 to 0.10; P = .007; n = 36 371; mean [SD] age, 57.51 [8.00] years; 19 843 female [54.56%]).

Conclusions and Relevance

This study provides novel insights into the cellular underpinnings of retinal alterations in neuropsychiatric and neurological disorders and highlights the retina as a potential proxy to study synaptic pathology in schizophrenia.

Reference-Based Standardization Approach Stabilizing Small Batch Risk Prediction via Polygenic Score

The polygenic score (PGS) holds promise for motivating preventive behavioral changes. However, no clinically validated standardization methodology currently exists. Here, we demonstrate the efficacy of a "reference-based" approach for standardization. This method uses the PGS distribution in the general population as a reference for normalization and percentile determination; however, it has not been validated. We investigated three potential influences on PGS computation: (1) the size of the reference population, (2) biases associated with different genotyping platforms, and (3) inclusion of kinship ties within the reference group. Our results indicate that the reference size affects the bootstrap estimate of standard error for PGS percentiles, peaking around the 50th percentile and diminishing at extreme percentiles (1st or 100th). Discrepancies between genotyping platforms, such as different microarrays and whole-genome sequencing, resulted in deviations in PGS (p < 0.05 in Kolmogorov-Smirnov test). However, these deviations were reduced to a nonsignificant level using shared genetic variants in the calculations when the ancestry of the samples and reference were matched. This approach recovered approximately 9.6% of the positive predictive value of PGS by naïve genotype. Our results provide fundamental insights for establishing clinical guidelines for implementing PGS to communicate reliable risks to individuals.

Polygenic score integrating neurodegenerative and vascular risk informs dementia risk stratification

INTRODUCTION

An integrative polygenic risk score (iPRS) capturing the neurodegenerative and vascular contribution to dementia could identify high-risk individuals and improve risk prediction.

METHODS

We developed an iPRS for dementia (iPRS-DEM) in Europeans (aged 65+), comprising genetic risk for Alzheimer's disease (AD) and 23 vascular or neurodegenerative traits (excluding apolipoprotein E [APOE]). iPRS-DEM was evaluated across cohorts comprising older community-dwelling people (N = 3702), a multi-ancestry biobank (N = 130,797 Europeans; 105,404 non-Europeans), and dementia-free memory clinic participants (N = 2032).

RESULTS

iPRS-DEM was associated with dementia risk independently of APOE in the elderly (subdistribution hazard ratio [sHR]per1SD = 1.15, 95% confidence interval [CI]: 1.03 to 1.28), which generalized to Europeans (EUR-sHRper1SD = 1.28, 95% CI: 1.09 to 1.51]), East-Asians (EAS-sHRper1SD = 5.29, 95% CI: 1.43 to 34.36), and memory-clinic participants (sHRper1SD = 1.25, 95% CI: 1.11 to 1.42). Prediction was comparable to clinical risk factors in older community-dwelling people, with improved performance among memory-clinic patients. Risk stratification was enhanced by defining four genetic risk groups with iPRS-DEM and APOE ε4, reaching five-fold increased risk in APOE ε4+/iPRS-DEM+ memory-clinic participants.

DISCUSSION

Alongside APOE ε4, iPRS-DEM may refine risk stratification for the enrichment of dementia clinical trials and prevention programs.

HIGHLIGHTS

iPRS-DEM reflects neurodegenerative and vascular contribution to dementia. We show iPRS-DEM captures additional dementia genetic risk beyond APOE and AD-PRS. iPRS-DEM, in combination with APOE ε4, shows promise for dementia risk stratification. Our results generalize across both population-based and memory-clinic settings. We show transportability of iPRS-DEM to East Asian ancestry.

How epigenetics impacts stroke risk and outcomes through DNA methylation: A systematic review

The impact of DNA methylation (DNAm) on epigenetics has gained prominence in recent years due to its potential influence on ischemic stroke (IS) and treatment outcomes. DNAm is reversible and a better understanding of its role in IS could help identify novel therapeutic targets. The aim of this systematic review was to compile the available data on DNAm in the risk and prognosis of IS and to explore its therapeutic potential. The review process followed the PRISMA criteria. We searched the Pubmed and Cochrane databases to identify studies that used hypothesis free methodological approaches. Of the 459 studies identified, 34 met the inclusion criteria. The studies were categorized as follows: risk of IS; outcomes; and DNAm age. Most studies used genotyping array technology rather than whole-genome sequencing. DNAm testing was mainly based on blood samples. Most studies involved European cohorts. Most of the studies were performed at a single-center with recruitment at the time of stroke. In a few studies, health status was determined longitudinally. This systematic review shows that IS patients are biologically older than expected and present characteristic DNAm patterns related to stroke risk and outcomes. These patterns could be used to develop new treatments with epidrugs.

A new nomogram for predicting 90-day outcomes of intravenous thrombolysis in patients with acute ischaemic stroke

Background

The aim of this study was to construct and validate a new nomogram to predict the risk of poor outcome in patients with acute ischemic stroke (AIS) after intravenous thrombolytic therapy (IVT).

Methods

A total of 425 patients who received IVT within 4.5 h of stroke onset were included in a retrospective study. All the patients were divided into training (70%, n = 298) and validation cohorts (30%, n = 127). Poor outcome (defined as a 90-day modified Rankin Scale score 3-5) was the primary outcome. Logistic regression was used for analysis of independent risk factors for poor outcome in patients with AIS. Nomograms of poor outcome in AIS patients were constructed using R software. Discrimination and calibration of the models were assessed using area under the receiver operating characteristic (ROC) curve (AUC) and calibration plots.

Results

Multifactorial logistic regression analysis showed that SII (OR = 1.001, 95% CI: 1.000-1.002, p = 0.008), SIRI (OR = 1.584, 95% CI: 1.122-2.236, p = 0.009), NIHSS (OR = 1.101, 95% CI: 1.044-1.160, p < 0.001), and history of diabetes mellitus (OR = 2.582, 95% CI: 1.285-5.188, p = 0.008) were the independent risk factors for the occurrence of poor outcome in AIS patients. The poor outcome nomogram for AIS patients was constructed based on the above independent risk factors. The training and validation cohort AUCs of the nomogram were 0.854 (95% CI: 0.807-0.901) and 0.855 (95% CI: 0.783-0.927), respectively. The prediction models were well calibrated in both the training and validation cohorts. The net benefit of the nomograms was better when the threshold probability ranges were 4.28-66.4% and 4.01-67.8% for the training and validation cohorts, respectively.

Conclusion

New nomogram includes NIHSS, SII, SIRI and diabetes as variables with the potential to predict the risk of 90-day outcomes in patients with AIS following IVT.

2025 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2025 AHA Statistical Update is the product of a full year's worth of effort in 2024 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. This year's edition includes a continued focus on health equity across several key domains and enhanced global data that reflect improved methods and incorporation of ≈3000 new data sources since last year's Statistical Update.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Genetics of cardiovascular outcomes in individuals with chronic kidney disease: the Chronic Renal Insufficiency Cohort (CRIC) study

Genome-wide association studies (GWAS) identified multiple loci for cardiovascular disease, but their relevance to individuals with chronic kidney disease (CKD), who are at higher risk of cardiovascular disease, is unknown. In this study, we performed GWAS analyses of coronary heart disease (CHD) or all-cause stroke in African (AFR) and European (EUR) American participants with CKD of the Chronic Renal Insufficiency Cohort (CRIC). Mixed- effect logistic regression models were race-stratified and adjusted for age, sex, site of recruitment, estimated glomerular filtration rate (eGFR), and principal components, followed by meta-analysis. We attempted replication in participants from two biobanks with biomarker or ICD-10 (International Classification of Diseases, 10th Revision) diagnostic codes for CKD. We assessed the association of single nucleotide variants (SNVs) at known CHD and stroke loci in CRIC and tested the genetic correlation among CRIC, a biobank-based cohort and published GWAS of cardiovascular disease. Among 3,588 CRIC participants, 1,203 had CHD and 535 had all-cause stroke. We identified six SNVs across three loci ( LINC02744 , AZIN1- AS1 , and ATP6V0A4 ) associated with all-cause stroke, and two intronic SNVs at the PPARG locus associated with CHD. However, SNV associations were not significant in replication studies. Published SNVs for CHD or stroke were not associated with cardiovascular outcomes in CRIC. When testing the genetic correlations between published GWAS and CRIC GWAS, they were significant for CHD (genetic correlations (rg) range of 0.39 to 0.51, p-value< 0.007). These findings suggest some differences in the genetic architecture of CHD and stroke among individuals with CKD compared to those from the general population, although large numbers of CKD participants are needed to assess if findings are related to participant selection and CKD severity, or non-traditional risk factors in people with CKD.

MTHFR Polymorphisms, Homocysteine Elevation, and Ischemic Stroke Susceptibility in East Asian and European Populations

BACKGROUND AND OBJECTIVES

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme that regulates folate and homocysteine metabolism. Genetic variation in MTHFR has been implicated in cerebrovascular disease risk, although research in diverse populations is lacking. We thus aimed to investigate the effect of genetically predicted MTHFR activity on risk of ischemic stroke (IS) and its main subtypes using a multiancestry Mendelian randomization (MR) approach.

METHODS

We proxied reduced MTHFR function using the C677T missense variant that impairs MTHFR function and consequently increases levels of total plasma homocysteine (tHcy) in both East Asian and European populations. Summary data for IS and its subtypes (small vessel stroke [SVS], large artery stroke [LAS], and cardioembolic stroke [CES]) were obtained from the largest available genome-wide association studies. MR estimates were calculated using the Wald ratio and random-effects inverse-variance-weighted methods. We performed sensitivity analyses to evaluate for confounding due to linkage disequilibrium.

RESULTS

Genetically downregulated MTHFR activity, associated with a consequent SD increase in tHcy levels, was associated with an increased risk of SVS in both East Asian (odds ratio [OR] 1.20, 95% CI 1.08-1.34, p = 8.58 × 10-4) and European populations (OR 1.62, 95% CI 1.24-2.12; p = 3.73 × 10-4). There was no evidence that genetically perturbed MTHFR activity influenced risk of CES or LAS. These findings were consistent in sensitivity analyses.

DISCUSSION

Our findings provide genetic evidence that reduced MTHFR activity was selectively associated with an increased risk of SVS in both East Asian and European populations. These findings warrant further investigation of genotype-guided nutritional supplementation for the prevention of SVS.

Kidney multiome-based genetic scorecard reveals convergent coding and regulatory variants

Kidney dysfunction is a major cause of mortality, but its genetic architecture remains elusive. In this study, we conducted a multiancestry genome-wide association study in 2.2 million individuals and identified 1026 (97 previously unknown) independent loci. Ancestry-specific analysis indicated an attenuation of newly identified signals on common variants in European ancestry populations and the power of population diversity for further discoveries. We defined genotype effects on allele-specific gene expression and regulatory circuitries in more than 700 human kidneys and 237,000 cells. We found 1363 coding variants disrupting 782 genes, with 601 genes also targeted by regulatory variants and convergence in 161 genes. Integrating 32 types of genetic information, we present the "Kidney Disease Genetic Scorecard" for prioritizing potentially causal genes, cell types, and druggable targets for kidney disease.

Integrative proteogenomic analysis identifies COL6A3-derived endotrophin as a mediator of the effect of obesity on coronary artery disease

Obesity strongly increases the risk of cardiometabolic diseases, yet the underlying mediators of this relationship are not fully understood. Given that obesity strongly influences circulating protein levels, we investigated proteins mediating the effects of obesity on coronary artery disease, stroke and type 2 diabetes. By integrating two-step proteome-wide Mendelian randomization, colocalization, epigenomics and single-cell RNA sequencing, we identified five mediators and prioritized collagen type VI α3 (COL6A3). COL6A3 levels were strongly increased by body mass index and increased coronary artery disease risk. Notably, the carboxyl terminus product of COL6A3, endotrophin, drove this effect. COL6A3 was highly expressed in disease-relevant cell types and tissues. Finally, we found that body fat reduction could reduce plasma levels of COL6A3-derived endotrophin, indicating a tractable way to modify endotrophin levels. In summary, we provide actionable insights into how circulating proteins mediate the effects of obesity on cardiometabolic diseases and prioritize endotrophin as a potential therapeutic target.

Circulating plasma protein identified as a therapeutic target for intracranial aneurysm through Mendelian Randomization analysis

BACKGROUND

Intracranial aneurysms are the main cause of subarachnoid hemorrhage (SAH), a severe stroke with devastating effects. However, there are no existing medications for intracranial aneurysms (IAs) and novel therapeutic targets are required.

METHODS

We performed a summary data-based Mendelian Randomization (MR) analysis to explore the causal association between circulating plasma proteins and the risk of IAs and SAH. Colocalization analysis was conducted to identify shared causal variants between circulating plasma proteins and IAs, as well as SAH. Finally, mediation MR analyses were conducted to clarify the role of potential plasma proteins in aneurysm formation.

RESULTS

Proteome-wide MR analysis showed that FGF5 (fibroblast growth factor 5) had a causal effect on IA and SAH risk (Pfdr < 0.05). Moreover, genetic variants affecting FGF5 expression levels showed strong evidence of colocalization with IA risk (PPH4 = 0.993) and SAH risk (PPH = 0.988), suggesting that this protein represents a potential direct target for IA intervention. Mediation analysis using two-step MR showed that systolic blood pressure and diastolic blood pressure mediate the effects of FGF5 on IA and SAH.

CONCLUSION

Our investigation identified a causal connection between FGF5 and IAs.

Comparing Alzheimer's genes in African, European, and Amerindian induced pluripotent stem cell-derived microglia

INTRODUCTION

Genome-wide association studies (GWAS) studies in Alzheimer's disease (AD) demonstrate ancestry-specific loci. Previous studies in the regulatory architecture have only been conducted in Europeans (EUs), thus studies in additional ancestries are needed. Given the prevalence of AD genes expressed in microglia, we initiated our studies in induced pluripotent stem cell (iPSC) -derived microglia.

METHODS

We created iPSC-derived microglia from 13 individuals of either high Amerindian (AI), African (AF), or EU global ancestry, including both AD and controls. RNA-seq, ATAC-seq, and pathway analyses were compared between ancestries in both AD and non-AD genes.

RESULTS

Twelve AD genes were differentially expressed genes (DEGs) and/or accessible between ancestries, including ABI3, CTSB, and MS4A6A. A total of 5% of all genes had differential ancestral expression, but differences in accessibility were less than 1%. The DEGs were enriched in known AD pathways.

DISCUSSION

This resource will be valuable in evaluating AD in admixed populations and other neurological disorders and understanding the AD risk differences between populations.

HIGHLIGHTS

First comparison of the genomics of AI, AF, and EU microglia. Report differences in expression and accessibility of AD genes between ancestries. Ancestral expression differences are greater than differences in accessibility. Good transcriptome correlation was seen between brain and iPSC-derived microglia. Differentially expressed AD genes were in known AD pathways.

Genome-wide and phenome-wide studies provided insights into brain glymphatic system function and its clinical associations

We applied an MRI technique diffusion tensor imaging along the perivascular space (DTI-ALPS) for assessing glymphatic system (GS) in a genome-wide association study (GWAS) and phenome-wide association study (PheWAS) of 40,486 European individuals. Exploratory analysis revealed 17 genetic loci significantly associating with the regional DTI-ALPS index. We found 58 genes, including SPPL2C and EFCAB5, which prioritized in the DTI-ALPS index subtypes and associated with neurodegenerative diseases. PheWAS of 241 traits suggested that body mass index and blood pressure phenotypes closely related to GS function. Moreover, we detected disrupted GS function in 44 of 625 predefined disease conditions. Notably, Mendelian randomization and mediation analysis indicated that lower DTI-ALPS index was a risk factor for ischemic stroke (odds ratio = 1.56, P = 0.028) by partly mediating the risk factor of obesity. Results provide insights into the genetic architecture and mechanism for the DIT-ALPS index and highlight its great clinical value, especially in cerebral stroke.