O96 NICD LACTYLATION OF NOTCH SIGNALING IMPROVES MICROVASCULATION RAREFACTION IN HYPERTENSION

Background and Objective: Microvascular rarefaction is a key pathophysiologic basis of hypertension-related cardiovascular disease. Exercise decreases blood pressure and promotes angiogenesis related to inhibition of NOTCH signaling. The activation of the NOTCH pathway depends on the transcriptional regulation of its intracellular active fragment NICD after nuclear translocation. The post-translational modification status of proteins plays a crucial role in the nuclear translocation effect of transcription factors. Lactylation is influenced by the level of lactate in the body. Exercise can promote glycolysis in endothelial cells, and increase intracellular lactate levels. Therefore, we explored whether the beneficial effects of Exercise were mediated by promoting NICD lactylation, inhibiting the NOTCH signaling, and promoting angiogenesis. Methods: To test our hypotheses, WKYs (normotensive rats) and SHRs (spontaneously hypertensive rats) were given exercise for 12 weeks. Blood pressure was determined by the tail-cuff method, and cardiac function was assessed by echocardiography. Using rats’ retina, gastrocnemius, and myocardium detected microvascular density. The expression levels of NOTCH signaling pathway related proteins and angiogenesis related factors were measured by Western Blotting. The level of lactate was measured by using a lactate assay kit. Protein modification omics was used to detect the modification types and levels of NICD in microvascular endothelial cells, followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) to detect the lactylation sites of NICD in microvascular endothelial cells. Results: Exercise in SHRs resulted in reduced blood pressure and concentric hypertrophy. Exercise promoted angiogenesis and improved microcirculation rarefaction. Exercise also reduced the production of NOTCH pathway related proteins and increased the expression level of angiogenesis related factors. The lactate level increased after exercise, and the lactylation level of NICD increased. Conclusions: In summary, Exercise decreases hypertension and improves cardiac function in SHRs. Our research results indicated that exercise increases lactate production and induces NICD lactylation, thereby inhibiting the NOTCH signaling, upregulating the expression of angiogenic factors, promoting angiogenesis, and lowering blood pressure.