Immune cells mediate the association between different lipids and knee osteoarthritis:a genome-wide association analysis of European individuals
BACKGROUND:Observational studies have found a dual effect of lipids and immune cells on osteoarthritis progression,but the exact mechanism of action is not yet clear.OBJECTIVE:To investigate whether the causal relationship between lipids and knee osteoarthritis is regulated by immune cells.METHODS:179 lipids were obtained from the Linda Ottensman database,731 immune cell-associated single nucleotide polymorphisms were obtained from Open GWAS as instrumental variables,and genome-wide association data for knee osteoarthritis were obtained from the Osteoarthritis Genetics Consortium.First,we used a two-sample Mendelian randomization method to investigate the causal relationships between lipids and knee osteoarthritis,between immune cells and knee osteoarthritis,and between lipids and immune cells from a genetic perspective.In addition,Bayesian-weighted Mendelian randomization verified the causal relationship between lipids and knee osteoarthritis,and reverse Mendelian randomization and Steiger directionality test assessed the positive relationship.Second,sensitivity analyses were performed,including Cochran's Q test to eliminate heterogeneity,MR-PRESSO global test and MR-Egger intercept to rule out horizontal pleiotropy,and leave-one-out method to assess the effect of individual single nucleotide polymorphism drivers on random estimates.Finally,the mediating effect of specific immune cell traits in the causal relationship between lipids and knee osteoarthritis was determined by a two-step Mendelian randomization method.RESULTS AND CONCLUSION:The inverse variance weighting method and Bayesian-weighted algorithm together identified eight lipid species that were causally associated with knee osteoarthritis.The results of Cochran's Q,MR-PRESSO,and MR-Egger intercept were not statistically significant(P<0.05).Meanwhile,a total of three sets of mediated relationships were calculated,with the lowest mediation percentage of 11.85%and the highest of 45.48%.These findings indicate the level of immune cells plays a potential role in the regulatory process of lipids and knee osteoarthritis,which provides new perspectives for in-depth exploration of knee osteoarthritis.
lipidsknee osteoarthritisMendelian randomizationimmune cellsmediation analysiscausal relationshipengineered tissue construction