Chen, Jingshu, Jamaiyar, Anurag, Wu, Winona, Hu, Yi, Zhuang, Rulin, Sausen, Grasiele, Cheng, Henry S., de Oliveira Vaz, Camila, Pérez-Cremades, Daniel, Tzani, Aspasia, McCoy, Michael G., Assa, Carmel, Eley, Samuel, Randhawa, Vinay, Lee, Kwangwoon, Plutzky, Jorge, Hamburg, Naomi M., Sabatine, Marc S., and Feinberg, Mark W.
Diabetes-associated atherosclerosis involves excessive immune cell recruitment and plaque formation. However, the mechanisms remain poorly understood. Transcriptomic analysis of the aortic intima in Ldlr−/−mice on a high-fat, high-sucrose-containing (HFSC) diet identifies a macrophage-enriched nuclear long noncoding RNA (lncRNA), MERRICAL(macrophage-enriched lncRNA regulates inflammation, chemotaxis, and atherosclerosis). MERRICALexpression increases by 249% in intimal lesions during progression. lncRNA-mRNA pair genomic mapping reveals that MERRICALpositively correlates with the chemokines Ccl3 and Ccl4. MERRICAL-deficient macrophages exhibit lower Ccl3 and Ccl4 expression, chemotaxis, and inflammatory responses. Mechanistically, MERRICALguides the WDR5-MLL1 complex to activate CCL3 and CCL4 transcription via H3K4me3 modification. MERRICALdeficiency in HFSC diet-fed Ldlr−/−mice reduces lesion formation by 74% in the aortic sinus and 86% in the descending aorta by inhibiting leukocyte recruitment into the aortic wall and pro-inflammatory responses. These findings unveil a regulatory mechanism whereby a macrophage-enriched lncRNA potently inhibits chemotactic responses, alleviating lesion progression in diabetes.