Lactylation of PLBD1 Facilitates Brain Injury Induced by Ischemic Stroke.

Background: Ischemic stroke is a prevalent global condition and its associated brain damage poses a significant threat to patient survival and outcomes. The underlying mechanisms of ischemic stroke-induced brain injury remain elusive, necessitating further investigation.

Methods: Ischemic stroke models were established using middle cerebral artery occlusion (MCAO) in animals and oxygen-glucose deprivation and reperfusion (OGD-R) in cells. Phospholipase B domain-containing protein 1 (PLBD1) expression in these models was assessed via western blotting analysis, reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR), and cell immunofluorescence. A comprehensive evaluation, incorporating cellular lactate dehydrogenase (LDH) release assays, glycolysis metabolism kits, RT-qPCR, western blotting, triphenyl tetrazolium chloride (TTC) staining, neurological scoring, brain tissue water content measurement, and creatine kinase-MB (CK-MB) analysis, was conducted to determine the impact of PLBD1 on brain injury. Potential lactylation sites in PLBD1 were predicted using the DeepKla database, with western blotting and co-immunoprecipitation (Co-IP) confirming the lactylation site.

Results: PLBD1 was significantly upregulated in the brain tissue of MCAO animal models and OGD-R-treated cells. PLBD1 knockdown markedly mitigated OGD-R-induced cellular injury, suppressed glycolysis in vitro, and reversed MCAO-induced brain damage in vivo. Furthermore, lactylation at the K155 site of PLBD1 enhanced its expression in response to elevated lactate levels following OGD-R treatment. These results indicated that the upregulation of PLBD1 via K155 site lactylation plays a pivotal role in exacerbating ischemic stroke-induced brain damage.

Conclusion: Targeting the lactate/PLBD1 axis presents a promising therapeutic strategy for ischemic stroke management.