TRIB1 as a novel therapeutic target in endothelial dysfunction

Abstract Background Recent genome-wide association studies (GWAS) have implicated TRIB1 in cardiometabolic disorders. TRIB1 is a pseudokinase involved in lipid metabolism, inflammation, and insulin signaling; however, its direct role in vascular tissue remains poorly understood. This study aims to investigate the impact of TRIB1 activation on vascular function and to elucidate the underlying molecular mechanisms. Methods Human Aortic Endothelial Cells (HAOECs) and Aortic Smooth Muscle Cells (HAoSMCs) were treated with BRD0418, a pharmacological activator of TRIB1, and TRIB1 expression was assessed by Western blot. Nitric oxide (NO) production was quantified by DAF-FM diacetate staining. Vascular reactivity was performed in isolated murine mesenteric arteries using a pressure myograph. Vessels were pre-treated with the eNOS inhibitor L-NAME and/or BRD0418, and exposed to acetylcholine (Ach) and nitroglycerin to assess endothelium-dependent and endothelium-independent vasodilation, respectively. Proteomic profiling was performed using LC-MS/MS–based quantitative mass spectrometry to identify the TRIB1 proteomic profile. Results We found that BRD0418, a compound previously identified as a TRIB1 inducer, markedly increased TRIB1 expression in both HAOEC and HAoSMC. Mass spectrometry analysis revealed multiple signaling pathways modulated following BRD0418 exposure, with significant enrichment of redox-regulatory pathways indicative of the activation of oxidative stress–related mechanisms. Conversely, down-regulated pathways were predominantly associated with DNA replication and cytoskeletal organization, suggesting a reduction in proliferation and impaired structural homeostasis of endothelial cells. Functionally, ex vivo vascular reactivity studies demonstrated impaired acetylcholine- and nitroglycerin-induced vasorelaxation, indicating both endothelium-dependent and endothelium-independent dysfunction. Moreover, BRD0418 further exacerbated eNOS inhibitor L-NAME–induced endothelial dysfunction, supporting a mechanism involving reduced NO bioavailability. Consistently, DAF-FM staining confirmed a reduction in NO production in mesenteric arteries exposed to BRD0418. Finally, arteries isolated from hypertensive mice exhibited elevated Trib1 expression compared with normotensive controls, further linking TRIB1 upregulation to vascular dysfunction. Conclusion BRD0418-induced TRIB1 upregulation promotes oxidative stress–related proteomic remodeling while suppressing pathways linked to DNA replication and cytoskeletal integrity, indicating impaired endothelial homeostasis. TRIB1 activation also reduces NO bioavailability and exacerbates endothelial vasorelaxation. Higher Trib1 levels observed in hypertensive vessels further support its contribution to vascular impairment and highlight TRIB1 as a potential target in cardiovascular disease.