Psychological stress contributes to cardiovascular disease (CVD) and sudden cardiac death, yet its molecular basis remains obscure. RNA binding protein RBM24 plays a critical role in cardiac development, rhythm regulation, and cellular stress. Here, we show that psychological stress activates RBM24 S181 phosphorylation through eIF4E2-GSK3β signaling, which causally links psychological stress to CVD by promoting APOE translation (apolipoprotein E). Using an Rbm24 S181A KI mouse model, we show that impaired S181 phosphorylation leads to cardiac contractile dysfunction, atrial fibrillation, dyslipidemia, reduced muscle strength, behavioral abnormalities, and sudden death under acute and chronic psychological stressors. The impaired S181 phosphorylation of RBM24 inhibits cardiac translation, including APOE translation. Notably, cardiomyocyte-specific expression of APOE rescues cardiac electrophysiological abnormalities and contractile dysfunction, through preventing ROS stress and mitochondrial dysfunction. Moreover, RBM24-S181 phosphorylation acts as a serum marker for chronic stress in human. These results provide a functional link between RBM24 phosphorylation, eIF4E-regulated APOE translation, and psychological-stress-induced CVD.

Hypoxia modulates senescence, but their physiological link remains unclear. Here, we found that eIF4E2, a hypoxia-activated translation initiation factor, interacted with GSK3β to maintain phosphorylation of p53, thus resisting senescence under hypoxia. RNA-binding protein RBM38 interacted with eIF4E to inhibit the translation of p53, but GSK3β-mediated Ser195 phosphorylation disrupted the RBM38-eIF4E interaction. Through investigation of RBM38 phosphorylation, we found that the eIF4E2-GSK3β pathway specifically regulated proline-directed serine/threonine phosphorylation (S/T-P). Importantly, peptides e2-I or G3-I that blocking eIF4E2-GSK3β interaction can inhibit the basal S/T-P phosphorylation of p53 at multiple sites, therby inducing senescence through transcriptional inhibition. Additionally, a nanobody was screened via the domain where eIF4E2 bound to GSK3β, and this nanobody inhibited S/T-P phosphorylation to promote senescence. Furthermore, hypoxia inhibited eIF4E2-GSK3β pathway by mediating S-Nitrosylation of GSK3β. Blocking eIF4E2-GSK3β interaction promoted liver senescence under hypoxia, thus leading to liver fibrosis, eventually accelerating N, N-diethylnitrosamine (DEN)-induced tumorigenesis. Interestingly, eIF4E2 isoforms with GSK3β-binding motif exclusively exist in mammals, which protect zebrafish heart against hypoxia. Together, this study reveals a mammalian eIF4E2-GSK3β pathway that prevents senescence by maintaining basal S/T-P phosphorylation of p53, which underlies hypoxia adaptation of tissues.

Indirect hepatotoxicity remains a major challenge in drug development because of limited evaluation tools and mechanistic insight. Here, we construct three-dimensional multi-lineage hepatic organoids comprising five liver cell types derived from human embryonic stem cells, and in a screen of 58 hepatotoxic drugs, identify imipramine as an inducer of indirect hepatotoxicity. Imipramine specifically engages tyrosine kinase receptor B expressed by non-parenchymal hepatic stellate cells, activating the p53/hnRNPA2B1/DGCR8 pathway, which drives selective enrichment of microRNA-34a-3p in hepatic stellate cell–derived exosomes, thereby converting them into toxic exosomes. These toxic exosomes transfer microRNA-34a-3p to hepatocytes, where it disrupts cellular homeostasis by downregulating the anti-apoptotic protein XIAP, thereby activating caspase3 and inducing apoptosis. Consistently, imipramine long-term gavage in vivo triggers hepatic stellate cell apoptosis and toxic exosome–mediated hepatocyte injury without direct hepatocyte toxicity. Our findings establish a biomimetic organoid platform for precision drug testing and highlight the central role of intercellular communication in drug-induced liver injury.

Metabolic diseases are jointly driven by insulin resistance, chronic inflammation, lipotoxicity, and disrupted organelle homeostasis arising from sustained nutrient overload. These disorders substantially increase the risk of cardiovascular, renal, and other multi-organ complications and have become a major global public health burden. Mitochondria are central organelles that integrate energy metabolism with stress signaling. They participate in fatty acid β-oxidation, the tricarboxylic acid cycle, and oxidative phosphorylation, while also regulating reactive oxygen species generation, mitochondrial DNA-related inflammatory signaling, calcium homeostasis, and cell death. Under chronic metabolic stress, the mitochondrial quality control (MQC) system shifts from adaptive repair toward decompensation, characterized by impaired mitochondrial biogenesis, abnormal mitochondrial dynamics, defective mitophagy, disrupted proteostasis and mitochondrial unfolded protein response, increased oxidative stress, and impaired metabolic reprogramming. Natural small molecules possess structural diversity and multi-target, multi-pathway regulatory properties. They can modulate multiple MQC processes and improve mitochondrial function and metabolic phenotypes in preclinical models. Novel formulations, structural optimization, and mitochondria-targeted delivery can further improve their solubility, bioavailability, tissue exposure, and subcellular localization, thereby enhancing therapeutic efficacy and translational potential. This review systematically summarizes the mechanisms of MQC dysregulation in metabolic diseases, the evidence supporting natural small-molecule interventions, and strategies for formulation and delivery optimization. Future studies should strengthen causal validation of MQC, quantify intramitochondrial drug exposure, and incorporate clinically relevant endpoints to facilitate the translation of natural small-molecule MQC modulators.