Abstract
Metastasis-associated lung adenocarcinoma transcript 1(MALAT1) is associated with vascular calcification and diabetes-related complications. However, the effect of exosomal MALAT1 derived from macrophages induced by hyperglycemia on vascular calcification (VC) remains unclear. In this study, we investigated the effect of VC and its regulatory mechanisms in cultured vascular smooth muscle cells (VSMCs) and diabetic rats by exosomal MALAT1 derived from macrophages treated with high levels of glucose. Macrophages and VSMCs were cultured in 25 mM glucose. Macrophages exposed to high glucose exhibited increased expression of exosomal MALAT1. When transferred to VSMCs, exosomal MALAT1 significantly suppressed the expression of miR-143-3p while upregulating Matrix Gla protein (MGP, an inhibitor of VC) mRNA and protein levels. Interventions using MALAT1 siRNA or miR-143-3p mimics effectively reversed this effect. Both MALAT1 siRNA and overexpression of miR-143-3p significantly increased the calcium content in cultured VSMCs and in the carotid artery of diabetic rats following balloon injury. Balloon injury to the carotid artery in diabetic rats treated with macrophage-derived exosomes significantly increased the expression of MALAT1 and MGP while reducing the expression of miR-143-3p in the carotid artery. These findings demonstrate that macrophage-derived exosomal MALAT1 modulates VC via the MALAT1/miR-143-3p/MGP axis under hyperglycemic conditions. The results suggest that targeting exosomal MALAT1 may offer a novel and effective therapeutic approach for mitigating VC in metabolic disorders such as diabetes.