A Novel Mechanism of Berberine Targeting EIF2AK2 Dimerization Attenuates Methylglyoxal-Induced Endothelial Senescence and Apoptosis

Vascular aging, a central feature of organismal aging, involves endothelial cell (EC) structural and functional alterations. Methylglyoxal (MGO), a key advanced glycation end product precursor, pathologically accumulates during aging. While MGO induces EC Apoptosis via mitochondrial pathways and endothelial dysfunction, its role in cellular senescence remains unclear. The integrated stress response (ISR) sensor Eukaryotic Translation Initiation Factor 2 Alpha Kinase 2 (EIF2AK2), also known as PKR, has emerged beyond its well-established Antiviral role as a critical regulator of cellular senescence. This study explores the novel mechanism of berberine (BBR) on targeting EIF2AK2 dimerization to attenuate MGO-induced EC senescence and Apoptosis. In vitro, MGO-treated HUVECs assessed EIF2AK2 dimerization/phosphorylation and senescence (p16, p21) and Apoptosis (cleaved Caspase-3) markers. In vivo, three aging models (MGO-induced aortic injury, D-gal-induced accelerated aging, natural aging) evaluated MGO accumulation and EIF2AK2 pathway activation (phospho-EIF2AK2, ATF4), demonstrating BBR's efficacy via EIF2AK2 axis modulation. Here, we present the first evidence demonstrating that EIF2AK2 dimerization and subsequent activation significantly exacerbate EC senescence and Apoptosis in both in vivo and in vitro models, characterized by upregulation of pro-apoptotic markers (Cleaved Caspase-3, Bax) and senescence-associated proteins (P53, P21, P16), along with downregulation of the anti-apoptotic protein Bcl-2. EIF2AK2 has been identified as a key cellular target of the natural isoquinoline alkaloid BBR. Our findings further establish that BBR ameliorates MGO-induced vascular EC senescence and Apoptosis through selective inhibition of EIF2AK2 dimerization and subsequent eIF2α phosphorylation. Notably, pharmacological suppression of EIF2AK2 with C16 synergistically enhances BBR's protective effects against MGO-induced EC senescence and Apoptosis. Collectively, this study reveals a novel mechanistic pathway by which MGO drives EC senescence/Apoptosis via EIF2AK2 dimerization/activation and validates BBR's therapeutic potential for vascular pathologies. EIF2AK2 emerges as a promising target for developing novel vascular protection strategies.

EIF2AK2; MGO; berberine; senescence.