Exploring susceptibility and therapeutic targets for kidney stones through proteome-wide Mendelian randomization

Given the high recurrence rate of kidney stones, surgical lithotripsy and stone removal are not the ultimate treatments for kidney stones. There's an urgent need to explore the genetic mechanisms behind the susceptibility to kidney stones and to identify potential targets for prevention, to reduce the renal damage caused by recurrent stone formation. In this study, we screened 4548 circulating proteins using proteome-wide Mendelian Randomization (MR) to find proteins with a causal relationship to kidney stone risk. Additionally, proteome-wide association study (PWAS) and colocalization analysis were used to validate and prioritize candidate proteins. Moreover, downstream analyses including single-cell analysis, enrichment analysis, protein-protein interaction (PPI), and druggability analysis were conducted on the proteins causally related to kidney stones, to further explore the genetic mechanisms of susceptibility and the potential of proteins as drug targets. Ultimately, 22 target proteins associated with the risk of kidney stones were identified. Six plasma proteins (COLGALT1, CLMP, LECT1, ITIH1, CDHR3, CPLX2) were negatively correlated with kidney stone risk, while the genetic overexpression of 16 target proteins (GJA1, STOM, IRF9, F9, TMPRSS11D, ADH1B, SPINK13, CRYBB2, TNS2, DOCK9, OXSM, MST1, IL2, LMAN2, ITIH3, KLRF1) increased the risk of kidney stones. Based on the PWAS and colocalization analysis results, the 22 target proteins were classified into 3 tiers: IL2, CPLX2, and LMAN2 as tier 1 proteins with the most compelling evidence, MST1, ITIH1, and ITIH3 as tier 2 proteins, and the rest as tier 3 proteins. Enrichment analysis and PPI showed that target proteins mainly affect the occurrence of kidney stones through leukocyte activation and cell junction assembly. Druggability analysis suggested that IL2, MST1, and ITIH1 have potential as drug targets, and potential drugs were evaluated through molecular docking. In summary, this study employed multiple analytical methods to screen plasma proteins related to susceptibility to kidney stones, providing new insights into the genetic mechanisms of kidney stones and potential targets for treatment and prevention.