Yongkang Tan

BACKGROUND AND AIMS: Vascular smooth muscle cell (VSMC) senescence is crucial for the development of atherosclerosis, characterized by metabolic abnormalities. Tumour necrosis factor receptor-associated protein 1 (TRAP1), a metabolic regulator associated with ageing, might be implicated in atherosclerosis. As the role of TRAP1 in atherosclerosis remains elusive, this study aimed to examine the function of TRAP1 in VSMC senescence and atherosclerosis. METHODS: TRAP1 expression was measured in the aortic tissues of patients and mice with atherosclerosis using western blot and RT-qPCR. Senescent VSMC models were established by oncogenic Ras, and cellular senescence was evaluated by measuring senescence-associated β-galactosidase expression and other senescence markers. Chromatin immunoprecipitation (ChIP) analysis was performed to explore the potential role of TRAP1 in atherosclerosis. RESULTS: VSMC-specific TRAP1 deficiency mitigated VSMC senescence and atherosclerosis via metabolic reprogramming. Mechanistically, TRAP1 significantly increased aerobic glycolysis, leading to elevated lactate production. Accumulated lactate promoted histone H4 lysine 12 lactylation (H4K12la) by down-regulating the unique histone lysine delactylase HDAC3. H4K12la was enriched in the senescence-associated secretory phenotype (SASP) promoter, activating SASP transcription and exacerbating VSMC senescence. In VSMC-specific Trap1 knockout ApoeKO mice (ApoeKOTrap1SMCKO), the plaque area, senescence markers, H4K12la, and SASP were reduced. Additionally, pharmacological inhibition and proteolysis-targeting chimera (PROTAC)-mediated TRAP1 degradation effectively attenuated atherosclerosis in vivo. CONCLUSIONS: This study reveals a novel mechanism by which mitonuclear communication orchestrates gene expression in VSMC senescence and atherosclerosis. TRAP1-mediated metabolic reprogramming increases lactate-dependent H4K12la via HDAC3, promoting SASP expression and offering a new therapeutic direction for VSMC senescence and atherosclerosis.

Macrophage activation is a hallmark of atherosclerosis, accompanied by a switch in core metabolism from oxidative phosphorylation to glycolysis. The crosstalk between metabolic rewiring and histone modifications in macrophages is worthy of further investigation. Here, we find that lactate efflux-associated monocarboxylate transporter 4 (MCT4)-mediated histone lactylation is closely related to atherosclerosis. Histone H3 lysine 18 lactylation dependent on MCT4 deficiency activated the transcription of anti-inflammatory genes and tricarboxylic acid cycle genes, resulting in the initiation of local repair and homeostasis. Strikingly, histone lactylation is characteristically involved in the stage-specific local repair process during M1 to M2 transformation, whereas histone methylation and acetylation are not. Gene manipulation and protein hydrolysis-targeted chimerism technology are used to confirm that MCT4 deficiency favors ameliorating atherosclerosis. Therefore, our study shows that macrophage MCT4 deficiency, which links metabolic rewiring and histone modifications, plays a key role in training macrophages to become repair and homeostasis phenotypes.

Endothelial-to-mesenchymal transition (EndMT) is a key driver of atherosclerosis. Aerobic glycolysis is increased in the endothelium of atheroprone areas, accompanied by elevated lactate levels. Histone lactylation, mediated by lactate, can regulate gene expression and participate in disease regulation. However, whether histone lactylation is involved in atherosclerosis remains unknown. Here, we report that lipid peroxidation could lead to EndMT-induced atherosclerosis by increasing lactate-dependent histone H3 lysine 18 lactylation (H3K18la) in vitro and in vivo, as well as in atherosclerotic patients’ arteries. Mechanistically, the histone chaperone ASF1A was first identified as a cofactor of P300, which precisely regulated the enrichment of H3K18la at the promoter of SNAI1, thereby activating SNAI1 transcription and promoting EndMT. We found that deletion of ASF1A inhibited EndMT and improved endothelial dysfunction. Functional analysis based on ApoeKOAsf1aECKO mice in the atherosclerosis model confirmed the involvement of H3K18la in atherosclerosis and found that endothelium-specific ASF1A deficiency inhibited EndMT and alleviated atherosclerosis development. Inhibition of glycolysis by pharmacologic inhibition and advanced PROTAC attenuated H3K18la, SNAI1 transcription, and EndMT-induced atherosclerosis. This study illustrates precise crosstalk between metabolism and epigenetics via H3K18la by the P300/ASF1A molecular complex during EndMT-induced atherogenesis, which provides emerging therapies for atherosclerosis.

BACKGROUND: Mitochondrial dysfunction is a key factor in the development of atherogenesis. METTL4 (methyltransferase-like protein 4) mediates N6- methyldeoxyadenosine (6mA) of mammalian mitochondrial DNA (mtDNA). However, the role of METTL4-mediated mitoepigenetic regulation in atherosclerosis is still unknown. This study aims to investigate the potential involvement of METTL4 in atherosclerosis, explore the underlying mechanism, and develop targeted strategies for treating atherosclerosis. METHODS: Expression levels of mtDNA 6mA and METTL4 were determined in atherosclerotic lesions. We explored the mechanism of METTL4 involvement in atherosclerosis using Mettl4 Mac -KO - Apoe -/ - and Mettl4 MUT - Apoe -/ - mice and cell models, as well as bone marrow transplantation. Natural compound libraries were screened to identify potent METTL4 antagonists. In addition, bioinspired proteolysis targeting chimera technology targeting macrophages within plaques was used to increase the efficacy of the METTL4 antagonist. RESULTS: The expression levels of mtDNA 6mA and METTL4 were significantly increased in plaque macrophages. Mettl4 Mac-KO - Apoe -/ - mice displayed suppressed mtDNA 6mA levels and atherosclerotic progression, which were reversed by METTL4 restoration through bone marrow transplantation (n=6). Mechanistically, elevated METTL4 expression reduces mitochondrial ATP6 (MT-ATP6) expression by suppressing its transcription, thereby impairing the activity of mitochondrial respiration chain complex V. This disruption leads to the accumulation of excess protons in the mitochondrial intermembrane space, causing mitochondrial dysfunction. Consequently, mtDNA is released into the cytoplasm, ultimately triggering inflammasome activation. All results were reversed by the mutation in the METTL4 methyltransferase active site. Mettl4 MUT - Apoe -/ - mice showed suppressed mtDNA 6mA levels and atherosclerotic progression and repaired mitochondrial function of macrophage, which were reversed by METTL4 restoration through bone marrow transplantation (n=6). Pemetrexed was identified as the first METTL4 antagonist to effectively alleviate atherosclerotic progression. Furthermore, we generated a proteolysis targeting chimera drug based on pemetrexed that specifically targeted METTL4 in macrophages within plaques, showing a promising therapeutic effect on atherosclerosis. CONCLUSIONS: This study revealed a novel mechanism by which mtDNA 6mA orchestrated mitochondrial function–related gene expression in macrophages, thereby promoting atherosclerosis. Through various experimental techniques, such as gene manipulation, pharmacological inhibition, and proteolysis targeting chimera, this study demonstrated that mtDNA 6mA and its specific enzyme METTL4 hold potential as therapeutic targets for atherosclerosis.

Abstract Senescence plays a critical role in the development and progression of various diseases. This study introduces an amorphous, high‐entropy alloy (HEA)‐based nanozyme designed to combat senescence. By adjusting the nanozyme's composition and surface properties, this work analyzes its catalytic performance under both normal and aging conditions, confirming that peroxide and superoxide dismutase (SOD) activity are crucial for its anti‐aging therapeutic function. Subsequently, the chiral‐dependent therapeutic effect is validated and the senolytic performance of D‐handed PtPd 2 CuFe across several aging models is confirmed. Through multi‐Omics analyses, this work explores the mechanism underlying the senolytic action exerted by nanozyme in depth. It is confirm that exposure to senescent conditions leads to the enrichment of copper and iron atoms in their lower oxidation states, disrupting the iron‐thiol cluster in mitochondria and lipoic acid transferase, as well as oxidizing unsaturated fatty acids, triggering a cascade of cuproptosis and ferroptosis. Additionally, the concentration‐dependent anti‐aging effects of nanozyme is validated. Even an ultralow dose, the therapeutic can still act as a senomorphic, reducing the effects of senescence. Given its broad‐spectrum action and concentration‐adjustable anti‐aging potential, this work confirms the remarkable therapeutic capability of D‐handed PtPd 2 CuFe in managing atherosclerosis, a disease involving various types of senescent cells.