Causal factors in primary open angle glaucoma: a phenome-wide Mendelian randomisation study

Exploring Potential Drug Targets in Multiple Cardiovascular Diseases: A Study Based on Proteome-Wide Mendelian Randomization and Colocalization Analysis

Background: Cardiovascular diseases (CVDs) encompass a group of diseases that affect the heart and/or blood vessels, making them the leading cause of global mortality. In our study, we performed proteome-wide Mendelian randomization (MR) and colocalization analyses to identify novel therapeutic protein targets for CVDs and evaluate the potential drug-related protein side effects. Methods: We conducted a comprehensive proteome-wide MR study to assess the causal relationship between plasma proteins and the risk of CVDs. Summary-level data for 4907 circulating protein levels were extracted from a large-scale protein quantitative trait loci (pQTL) study involving 35,559 individuals. Additionally, genome-wide association study (GWAS) data for CVDs were extracted from the UK Biobank and the Finnish database. Colocalization analysis was utilized to identify causal variants shared between plasma proteins and CVDs. Finally, we conducted a comprehensive phenome-wide association study (PheWAS) using the R10 version of the Finnish database. This study was aimed at examining the potential drug-related protein side effects in the treatment of CVDs. A total of 2408 phenotypes were included in the analysis, categorized into 44 groups. Results: The research findings indicate the following associations: (1) In coronary artery disease (CAD), the plasma proteins A4GNT, COL6A3, KLC1, CALB2, KPNA2, MSMP, and ADH1B showed a positive causal relationship (p-fdr < 0.05). LAYN and GCKR exhibited a negative causal relationship (p-fdr < 0.05). (2) In chronic heart failure (CHF), PLG demonstrated a positive causal relationship (p-fdr < 0.05), while AZGP1 displayed a negative causal relationship (p-fdr < 0.05). (3) In ischemic stroke (IS), ALDH2 exhibited a positive causal relationship (p-fdr < 0.05), while PELO showed a negative causal relationship (p-fdr < 0.05). (4) In Type 2 diabetes (T2DM), the plasma proteins MCL1, SVEP1, PIP4K2A, RFK, HEXIM2, ALDH2, RAB1A, APOE, ANGPTL4, JAG1, FGFR1, and MLN demonstrated a positive causal relationship (p-fdr < 0.05). PTPN9, SNUPN, VAT1, COMT, CCL27, BMP7, and MSMP displayed a negative causal relationship (p-fdr < 0.05). Colocalization analysis conclusively identified that AZGP1, ALDH2, APOE, JAG1, MCL1, PTPN9, PIP4K2A, SNUPN, and RAB1A share a single causal variant with CVDs (PPH3 + PPH4 > 0.8). Further phenotype-wide association studies have shown some potential side effects of these nine targets (p-fdr < 0.05). Conclusions: This study identifies plasma proteins with significant causal associations with CVDs, providing a more comprehensive understanding of potential therapeutic targets. These findings contribute to our knowledge of the underlying mechanisms and offer insights into potential avenues for treatment.

Extracellular Vesicles and Glaucoma: Opportunities and Challenges

PURPOSE

Glaucoma is one of the leading causes of irreversible blindness, characterized by progressive visual field loss. Several risk factors are associated with developing the disease. However, the exact mechanisms or pathological pathways involved are still unknown. There is an urgent need to find the mechanisms and biomarkers for early detection and therapy to halt progression or cure the disease. Extracellular vesicles (EVs), specifically exosomes, have emerged as a crucial player in all aspects of glaucoma, including pathogenesis to therapeutic application with their cell-cell communication properties.

METHODS

We performed a literature search on PubMed, Google Scholar, and Web of Science using different keywords. Next, we reviewed the literature with studies focusing on the role of EVs as a causative factor in disease progression, biomarker discovery based on their contents, and protection from glaucoma.

RESULTS

Studies summarized here provide reports of differential EV miRNA and protein expression alterations when communicating with aqueous humor drainage tissues. We described how EV contents are involved in various pathways, including extracellular matrix remodeling and miRNA-mediated oxidative stress transmission between outflow tissues, thereby contributing to glaucoma. Extracellular vesicles, mainly derived from mesenchymal stem cells protecting the optic nerve from degeneration, have also been discussed as potential therapies for glaucoma.

CONCLUSIONS

Overall, this review provides a comprehensive discussion of the role of extracellular vesicles in glaucoma. We identified the challenges in finding major signaling molecules of glaucoma etiology. Lastly, we highlighted future directions to improve the treatment of glaucoma by extracellular vesicles.

Evaluation of circulating plasma proteins in prostate cancer using mendelian randomization

BACKGROUND

The proteome is an important resource for exploring potential diagnostic and therapeutic targets for cancer. This study aimed to investigate the causal associations between plasma proteins and prostate cancer (PCa), and to explore the downstream phenotypes that plasma proteins may influence and potential upstream intervening factors.

METHODS

Proteome-wide Mendelian randomization was used to investigate the causal effects of plasma proteins on PCa. Colocalization analysis examined the common causal variants between plasma proteins and PCa. Summary-statistics-based Mendelian Randomization (SMR) analyses identified associations between the expression of protein-coding genes and PCa. Phenome-wide association study was performed to explore the effect of target proteins on downstream phenotypes. Finally, a systematic Mendelian randomization analysis between lifestyle factors and plasma proteins was performed to assess upstream intervening factors for plasma proteins.

RESULTS

The findings revealed a positive genetic association between the predicted plasma levels of nine proteins and an elevated risk of PCa, while four proteins exhibited an inverse association with PCa risk. SMR analyses revealed ZG16B, PEX14 in blood and ZG16B, NAPG in prostate tissue were potential drug targets for PCa. The genetic association of PEX14 with PCa was further supported by colocalization analysis. Further Phenome-wide association study showed possible side effects of ZG16B, PEX14 and NAPG as drug targets. 10 plasma proteins (RBP7, TPST1, NFASC, LAYN, HDGF, SERPIMA5, DLL4, EFNA3, LIMA1, and CCL27) could be modulated by lifestyle-related factors.

CONCLUSION

This study explores the genetic associations between plasma proteins and PCa, provides evidence that plasma proteins serve as potential drug targets and enhances the understanding of the molecular etiology, prevention and treatment of PCa.

Proteome-wide mendelian randomization identifies therapeutic targets for nephrolithiasis

Kidney Stone Disease (KSD) constitutes a multifaceted disorder, emerging from a confluence of environmental and genetic determinants, and is characterized by a high frequency of occurrence and recurrence. Our objective is to elucidate potential causative proteins and identify prospective pharmacological targets within the context of KSD. This investigation harnessed the unparalleled breadth of plasma protein and KSD pooled genome-wide association study (GWAS) data, sourced from the United Kingdom Biobank Pharma Proteomics Project (UKBPPP) and the FinnGen database version R10. Through Mendelian randomization analysis, proteins exhibiting a causal influence on KSD were pinpointed. Subsequent co-localization analyses affirmed the stability of these findings, while enrichment analyses evaluated their potential for pharmacological intervention. Culminating the study, a phenome-wide association study (PheWAS) was executed, encompassing all phenotypes (2408 phenotypes) catalogued in the FinnGen database version R10. Our MR analysis identified a significant association between elevated plasma levels of proteins FKBPL, ITIH3, and SERPINC1 and increased risk of KSD based on genetic predictors. Conversely, proteins CACYBP, DAG1, ITIH1, and SEMA6C showed a protective effect against KSD, documented with statistical significance (PFDR<0.05). Co-localization analysis confirmed these seven proteins share genetic variants with KSD, signaling a shared genetic basis (PPH3 + PPH4 > 0.8). Enrichment analysis revealed key pathways including hyaluronan metabolism, collagen-rich extracellular matrix, and serine-type endopeptidase inhibition. Additionally, our PheWAS connected the associated proteins with 356 distinct diseases (PFDR<0.05), highlighting intricate disease interrelations. In conclusion, our research elucidated a causal nexus between seven plasma proteins and KSD, enriching our grasp of prospective therapeutic targets.

Causal association among glaucoma, cerebral cortical structures, and Alzheimer's disease: insights from genetic correlation and Mendelian randomization

Glaucoma and Alzheimer's disease are critical degenerative neuropathies with global impact. Previous studies have indicated that glaucomatous damage could extend beyond ocular structures, leading to brain alterations potentially associated with Alzheimer's disease risk. This study aimed to explore the causal associations among glaucoma, brain alterations, and Alzheimer's disease. We conducted a comprehensive investigation into the genetic correlation and causality between glaucoma, glaucoma endophenotypes, cerebral cortical surficial area and thickness, and Alzheimer's disease (including late-onset Alzheimer's disease, cognitive performance, and reaction time) using linkage disequilibrium score regression and Mendelian randomization. This study showed suggestive genetic correlations between glaucoma, cortical structures, and Alzheimer's disease. The genetically predicted all-caused glaucoma was nominally associated with a decreased risk of Alzheimer's disease (OR = 0.96, 95% CI: 0.93-0.99, P = 0.013). We found evidence for suggestive causality between glaucoma (endophenotypes) and 20 cortical regions and between 29 cortical regions and Alzheimer's disease (endophenotypes). Four cortical regions were causally associated with cognitive performance or reaction time at a significant threshold (P < 6.2E-04). Thirteen shared cortical regions between glaucoma (endophenotypes) and Alzheimer's disease (endophenotypes) were identified. Our findings complex causal relationships among glaucoma, cerebral cortical structures, and Alzheimer's disease. More studies are required to clarify the mediation effect of cortical alterations in the relationship between glaucoma and Alzheimer's disease.

Proteome-wide Mendelian randomization identifies therapeutic targets for ankylosing spondylitis

Background

Ankylosing Spondylitis (AS) is a chronic inflammatory disorder which can lead to considerable pain and disability. Mendelian randomization (MR) has been extensively applied for repurposing licensed drugs and uncovering new therapeutic targets. Our objective is to pinpoint innovative therapeutic protein targets for AS and assess the potential adverse effects of druggable proteins.

Methods

We conducted a comprehensive proteome-wide MR study to assess the causal relationships between plasma proteins and the risk of AS. The plasma proteins were sourced from the UK Biobank Pharma Proteomics Project (UKB-PPP) database, encompassing GWAS data for 2,940 plasma proteins. Additionally, GWAS data for AS were extracted from the R9 version of the Finnish database, including 2,860 patients and 270,964 controls. The colocalization analysis was executed to identify shared causal variants between plasma proteins and AS. Finally, we examined the potential adverse effects of druggable proteins for AS therapy by conducting a phenome-wide association study (PheWAS) utilizing the extensive Finnish database in version R9, encompassing 2,272 phenotypes categorized into 46 groups.

Results

The findings revealed a positive genetic association between the predicted plasma levels of six proteins and an elevated risk of AS, while two proteins exhibited an inverse association with AS risk (P fdr < 0.05). Among these eight plasma proteins, colocalization analysis identified AIF1, TNF, FKBPL, AGER, ALDH5A1, and ACOT13 as shared variation with AS(PPH3+PPH4>0.8), suggesting that they represent potential direct targets for AS intervention. Further phenotype-wide association studies have shown some potential side effects of these six targets (P fdr < 0.05).

Conclusion

Our investigation examined the causal connections between six plasma proteins and AS, providing a comprehensive understanding of potential therapeutic targets.

Beyond the optic nerve: Genetics, diagnosis, and promising therapies for glaucoma

Glaucoma stands as a leading global cause of blindness, affecting millions. It entails optic nerve damage and vision loss, categorized into open-angle and closed-angle glaucoma with subtypes like POAG, ACG, XFG, PCG, PDG, and developmental glaucoma. The pathophysiological and genetic factors behind glaucoma remain partially understood, with past studies linking intraocular pressure (IOP) levels to retinal ganglion cell death. Open-angle glaucoma involves elevated resistance to aqueous outflow via the trabecular meshwork, while angle-closure glaucoma typically sees drainage pathways obstructed by the iris. Genes have been identified for POAG, ACG, XFG, PCG, PDG, and developmental glaucoma, allowing for early-onset detection and the emergence of gene therapy as an effective treatment. Nevertheless, diagnostic and treatment options have their constraints, necessitating large-scale, well-designed studies to deepen our grasp of genetics' role in glaucoma's pathogenesis. This review delves into glaucoma's risk factors, pathophysiology, genetics, diagnosis, and available treatment options, including gene therapy. Additionally, it suggests alternative therapies like yoga and meditation as adjunct treatments for glaucoma prevention. Overall, this review advances our comprehension of the pathophysiology and genetic associations of glaucoma while highlighting the potential of gene therapy as a treatment avenue. Further research is imperative to fully elucidate the genetic mechanisms underpinning glaucoma and to devise effective treatments.