Inhibition of glycolysis mitigate microglial-activation mediated neuroinflammation in vitro and in vivo

OBJECTIVE Microglial activation-mediated neuroinflammation plays an important pathological basis in the progression of many neurodegenerative diseases.Activated microglia cells show a metabolic shift from oxidative phos⁃phorylation to aerobic glycolysis.However,the molecular mechanism underlying the role of glycolysis in microglial activation and progres⁃sion of neuroinflammatory diseases have not yet been fully understood.METHODS The anti-inflammatory effects and its underlying mecha⁃nisms of glycolytic inhibition in vitro were exam⁃ined in lipopolysaccharide(LPS)activated BV-2 microglial cells or primary microglial cells by enzyme-linked immunosorbent assay(ELISA),quantitative reverse transcriptase polymerase chain reaction(RT-PCR),Western blotting,immunoprecipitation,Flow cytometry and nuclear factor kappa B(NF-κB)luciferase reporter assays.In vivo,the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-or LPS-induced Par⁃kinson disease(PD)models were constructed to explored the anti-inflammatory and neuropro⁃tective effects of glycolytic inhibitor.RESULTS Inhibition of glycolysis by specific inhibitors[2-DG and 3-bromopyruvic acid(3-BPA)],knockdown of glucose transporter type 1(Glut-1)or hexoki⁃nase(HK)Ⅱabolished LPS-induced expres⁃sion of proinflammatory genes in microglia cells.Mechanistic studies demonstrated that glyco⁃lytic inhibitors significantly inhibited LPS-induced mTOR phosphorylation,IKKβphosphorylation,IκB phosphorylation,IκB degradation,nuclear translocation of P65 and NF-κB luciferase activity.Furthermore,LPS-induced P65 acetyla⁃tion on lysine 310,which is mediated by NAD-dependent protein deacetylase sirtuin-1 and is critical for NF-kB activation,were inhibited by glycolytic inhibitors.A coculture study revealed that 2-DG reduced the cytotoxicity of activated microglia toward MES23.5 dopaminergic neuron cells with no direct protective effect.In vivo,2-DG significantly ameliorated MPTP or LPS induced DA neuron loss and glial cell activation.CONCLUSION Glycolysis is actively involved in microglial activation.Inhibition of glycolysis can ameliorate microglial activation-related neuroinflammatory diseases.