The role of RUNX1/NF-κB in regulating PVAT inflammation in aortic dissection

The pathogenesis of aortic dissection (AD), an aortic disease associated with high mortality, involves significant vascular inflammatory infiltration. However, the precise relationship between perivascular adipose tissue (PVAT) and aortic dissection remains incompletely understood. The objective of this study is to investigate the role of PVAT inflammation in the pathogenesis of aortic dissection and identify novel therapeutic targets for this disease. The mouse model of aortic dissection was established in this study through intraperitoneal injection of Ang II and administration of BAPN in drinking water. Additionally, control groups were established at different time points including the 2-week group, 3-week group, and 4-week group. qPCR and immunohistochemistry techniques were employed to detect the expression of inflammatory markers and RUNX1 in PVAT surrounding the thoracic aorta in mice. Additionally, an aortic dissection model was established using RUNX1 knockout mice, and the aforementioned indicators were assessed. The 3T3-L1 cells were induced to differentiate into mature adipocytes in vitro, followed by lentivirus transfection for the knockdown or overexpression of RUNX1. The study aimed to investigate the potential cell-to-cell interactions by co-culturing 3T3-L1 cells with A7r5 or RAW264.7 cells. Subsequently, human aortic PVAT samples were obtained through clinical surgery and the aforementioned indicators were detected. In comparison to the control group, the aortic dissection model group exhibited decreased expression of MMP-2 and NF-κB in PVAT, while TNF-α and RUNX1 expression increased. Suppression of RUNX1 expression resulted in increased MMP-2 and NF-κB expression in PVAT, along with decreased TNF-α expression. Overexpression of RUNX1 upregulated the expression levels of NF-Κb, MMP-2, and TNF-α in adipocytes, whereas knockdown of RUNX1 exerted an opposite effect. Macrophages co-cultured with adipocytes overexpressing RUNX1 exhibited enhanced CD86 expression, while vascular smooth muscle cells co-cultured with these adipocytes showed reduced α-SMA expression. In human samples, there was an increase in both RUNX1 and MMP-2 expression levels, accompanied by a decrease in TNF-α and NF-Κb expression. The presence of aortic dissection is accompanied by evident inflammatory alterations in the PVAT, and this phenomenon appears to be associated with the involvement of RUNX1. It is plausible that the regulation of PVAT's inflammatory changes by RUNX1/NF-κB signaling pathway plays a role in the pathogenesis of aortic dissection.