D-β-hydroxybutyrate upregulates tight junction protein zonula occludens-1 attenuating lipopolysaccharide-stimulated...

In neuroinflammation, cerebral microvascular hyperpermeability and blood-brain-barrier (BBB) damage caused by deficiency of tight junction protein Zonula Occludens-1 (ZO-1), is a common pathophysiological process in many central nervous system (CNS) diseases. The ketone body D-β-hydroxybutyrate (BHB) is known for its neuroprotective effects, but its potential role in enhancing ZO-1 generation to mitigate cerebral microvascular hyperpermeability in neuroinflammation remains unclear. Therefore, we used lipopolysaccharide (LPS)-stimulated mice and human umbilical vein endothelial cells (HUVECs) to model cerebral microvascular hyperpermeability and assess the effects of BHB on microvascular hyperpermeability and ZO-1 level. To identify mechanisms, we analyzed lysine β-hydroxybutyrylation (Kbhb) levels in cells, β-catenin binding to the ZO-1 promoter, and co-localization of Kbhb with β-catenin. The results showed that ten days of BHB treatment upregulated ZO-1 content and reduced cerebral microvascular hyperpermeability in LPS-stimulated mice. In addition, BHB promoted ZO-1 generation and reduced paracellular permeability in LPS-stimulated HUVECs. Mechanistically, BHB (3 mmol/L) significantly increased Kbhb levels in cells, which may directly facilitate the transcription of ZO-1. Moreover, clear nuclear co-localization between β-catenin and Kbhb was observed, suggesting a pivotal role for β-catenin in mediating Kbhb-associated transcriptional activation of ZO-1. In summary, BHB may enhance histone Kbhb modification and its interaction with β-catenin, thereby promoting ZO-1 generation and mitigating LPS-induced cerebral microvascular hyperpermeability. Future development of BHB may enhance its therapeutic efficacy, thereby supporting its translational potential for the treatment of CNS diseases.