Lipoxin Alleviates Diabetic Vascular Calcification via the YAP Pathway

Abstract

Background: Vascular calcification is highly prevalent in patients with diabetes and has detrimental consequences. However, no effective prevention and treatment methods are currently available. Extensive evidence has demonstrated the protective effect of lipoxin (LX) against vascular diseases. However, whether LX prevents diabetic vascular calcification remains unknown. Here, we tested the hypothesis that LX alleviated osteogenic differentiation and subsequent calcification of vascular smooth muscle cells (VSMCs).Methods: In vitro, human aortic smooth muscle cells (HASMCs) were incubated in osteogenic medium (OM) with advanced glycation end products (AGEs) and LX to further determine the underlying mechanisms. An in vivo diabetic mouse model was established using a combination of a high-fat diet and multiple formulations of low-dose streptozotocin (STZ). Cell culture, alkaline phosphatase (ALP) staining, ALP activity, Alizarin red staining, von kossa staining, determination of calcium content, western blot analysis, immunohistochemistry, and immunofluorescence staining and statistical analysis were used in our study. Results: AGEs dose-dependently induced calcification and expression of osteogenesis-related markers, including Runt-related transcription factor 2 (RUNX2), osteopontin (OPN), and type I collagen (COL1), coupled with the activation of yes-associated protein (YAP). Mechanistically, YAP activation enhanced the AGE-induced osteogenic phenotype and calcification, but inhibition of YAP signalling alleviated this trend. Consistent with the in vitro results, diabetes promoted YAP expression as well as the subcellular localisation of the protein in the nucleus in the arterial tunica media. Interestingly, treatment with LX reduced vascular osteogenesis and calcification in diabetic mice, which was correlated with the reduced YAP levels. In addition, LX significantly inhibited COL1 accumulation and modulated the extracellular matrix. Our results further demonstrated that a pharmacological agonist of YAP reversed LX-mediated protection against osteogenic phenotypic conversion and calcification in VSMCs.Conclusions: These results demonstrate that LX attenuates transdifferentiation and calcification of VSMCs in diabetes mellitus via the YAP signalling axis, suggesting that LX is a potent therapeutic strategy to prevent diabetic vascular calcification.