Lactylation-mediated activation of HSPA5 upregulates VGLL3 expression to inhibit mitophagy-dependent ferroptosis following intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating neurological disorder characterized by extensive neuronal death, in which ferroptosis has emerged as a central pathological mechanism. Yet, the role of mitophagy in regulating ferroptosis during ICH remains elusive. Herein, we identified a lactylation-mediated HSPA5 (heat shock protein family A (Hsp70) member 5)-VGLL3 (vestigial like family member 3) signaling axis that confers neuroprotection following ICH. We observed a marked upregulation of VGLL3 expression in ICH models, and loss-of-function experiments revealed that VGLL3 silencing exacerbated BNIP3 (BCL2/adenovirus E1B interacting protein 3)-BNIP3L/NIX (BCL2/adenovirus E1B interacting protein 3-like)-mediated, mitophagy-dependent ferroptosis. Mechanistically, VGLL3 enhanced EGLN3 (egl-9 family hypoxia-inducible factor 3) expression and reduced HIF1A/HIF-1α (hypoxia inducible factor 1, alpha subunit) stability, thereby suppressing BNIP3-BNIP3L-driven mitophagy. Upstream, HSPA5 activated VGLL3, and HSPA5 knockdown phenocopied the effects of VGLL3 silencing. Pharmacological activation of HSPA5 with the selective agonist BIP inducer X (BIX) suppressed mitophagy-dependent ferroptosis in cultured neurons, while in vivo BIX administration alleviated neuronal death and improved motor function in ICH mice. Epigenetic analyses further demonstrated that HSPA5 expression was transcriptionally modulated by histone H3-Lys18 (H3K18) lactylation, while its non-histone lactylation was catalyzed by the acetyltransferase EP300 (E1A binding protein p300) and removed by the NAD-dependent protein deacetylase SIRT1 (sirtuin 1). Collectively, our findings delineate a lactylation-driven HSPA5-VGLL3-EGLN3-HIF1A/HIF1-1α axis that represses BNIP3-BNIP3L-mediated, mitophagy-dependent ferroptosis. Targeting this pathway may provide a mechanistic rationale and therapeutic strategy for mitigating neuronal injury and functional deficits following ICH.Abbreviations: BNIP3: BCL2/adenovirus E1B 19 kDa protein-interacting protein 3; BNIP3L/NIX: BCL2/adenovirus E1B interacting protein 3-like; EGLN3: egl-9 family hypoxia-inducible factor 3; GPX4: glutathione peroxidase 4; GSH: glutathione; GSSG: oxidized glutathione; HIF1A/HIF-1α: hypoxia inducible factor 1, alpha subunit; HSPA5: heat shock protein family A (Hsp70) member 5; IB: immunoblot; ICH: intracerebral hemorrhage; MDA: malondialdehyde; ROS: reactive oxygen species; SLC7A11: solute carrier family 7 member 11; VGLL3: vestigial like family member 3.