Indoxyl sulfate and p-cresyl sulfate directly promote vascular calcification via activation of inflammation and coagulation pathways

Vascular calcification contributes to high cardiovascular mortality in chronic kidney disease (CKD) patients. An association between the uremic toxins indoxyl sulfate (IS) and p-cresyl sulfate (PCS) and cardiovascular disease has been suggested. This study provides strong etiological evidence for indoxyl sulfate and p-cresyl sulfate as major contributors to vascular calcification in chronic kidney disease patients. Continuous exposure to indoxyl sulfate or p-cresyl sulfate in rats with chronic kidney disease promotes moderate to severe calcification in the aorta and peripheral vessels. Unbiased proteomic analyses of arterial samples coupled to functional bioinformatics annotation analysis revealed that calcification events were associated with acute phase response signaling, coagulation and glucometabolic signaling pathways, while escape from toxin-induced calcification was linked with liver X receptors and farnesoid X/liver X receptor signaling pathways. Activation of inflammation and coagulation pathways in the arterial wall plays a pivotal role in toxin-induced calcification and strongly associates with hyperglycemia and insulin resistance. These findings reveal new perspectives to establish novel therapeutic targets to prevent, halt progression or cure vascular calcification.