An inflammatory transcriptomic signature in psoriasis associates with future cardiovascular events

Gaining new insights into the etiology of ulcerative colitis through a cross-tissue transcriptome-wide association study

Background

Genome-wide association studies (GWASs) have identified 38 loci associated with ulcerative colitis (UC) susceptibility, but the risk genes and their biological mechanisms remained to be comprehensively elucidated.

Methods

Multi-marker analysis of genomic annotation (MAGMA) software was used to annotate genes on GWAS summary statistics of UC from FinnGen database. Genetic analysis was performed to identify risk genes. Cross-tissue transcriptome-wide association study (TWAS) using the unified test for molecular signatures (UTMOST) was performed to compare GWAS summary statistics with gene expression matrix (from Genotype-Tissue Expression Project) for data integration. Subsequently, we used FUSION software to select key genes from the individual tissues. Additionally, conditional and joint analysis was conducted to improve our understanding on UC. Fine-mapping of causal gene sets (FOCUS) software was employed to accurately locate risk genes. The results of the four genetic analyses (MAGMA, UTMOST, FUSION and FOCUS) were combined to obtain a set of UC risk genes. Finally, Mendelian randomization (MR) analysis and Bayesian colocalization analysis were conducted to determine the causal relationship between the risk genes and UC. To test the robustness of our findings, the same approaches were taken to verify the GWAS data of UC on IEU.

Results

Multiple correction tests screened PIM3 as a risk gene for UC. The results of Bayesian colocalization analysis showed that the posterior probability of hypothesis 4 was 0.997 and 0.954 in the validation dataset. MR was conducted using the inverse variance weighting method and two single nucleotide polymorphisms (SNPs, rs28645887 and rs62231924) were included in the analysis (p < 0.001, 95%CI: 1.45-1.89). In the validation dataset, MR result was p < 0.001, 95%CI: 1.19-1.72, indicating a clear causal relationship between PIM3 and UC.

Conclusion

Our study validated PIM3 as a key risk gene for UC and its expression level may be related to the risk of UC, providing a novel reference for further improving the current understanding on the genetic structure of UC.

Prospective evaluation of cardiovascular risk and mortality in patients with psoriasis: An American population-based study

The association between psoriasis and cardiovascular disease (CVD) has long been discussed and continually refined. However, there is currently a lack of prospective studies on the cardiovascular risk attributed to psoriasis in the United States general population. Representative adult participants were selected from the National Health and Nutrition Examination Survey (NHANES). Risks of cardiovascular symptoms and diseases prevalence were evaluated between participants with and without psoriasis. The hazards for all-cause mortality and CVD mortality were stratified by psoriasis status. Mediation analysis was then conducted to identify potential mediators between psoriasis and cardiac death. Overall, 19 741 participants were included in the current study, 542 (2.7%) had psoriasis and 19 199 (97.3%) did not have psoriasis. After adjusting for known CVD risk factors, odds for hypertension (OR = 1.37, 95% CI: 1.13-1.66, p = 0.001), hypercholesterolemia (OR = 1.37, 95% CI: 1.13-1.64, p < 0.001) and angina pectoris (OR = 1.74, 95% CI: 1.11-2.60, p = 0.011) were higher in psoriasis patients. Compared with participants without psoriasis, moderate/severe but not mild patients showed significantly higher CVD mortality (HR = 2.55, 95% CI: 1.27-5.15, p = 0.009). This result was supported by subgroup analyses. Mediation analysis further suggested that the direct effect of moderate/severe psoriasis on CVD mortality accounted for 81.4% (65.8%-97.1%). Besides, the indirect effect might derive from disturbance of serum albumin, urea nitrogen and uric acid. Moderate-to-severe psoriasis is an independent risk factor for cardiovascular disease, making it necessary to regularly conduct cardiovascular disease-related examinations for patients with higher severity of psoriasis in clinical settings.