Experimental Type 2 diabetes and lipotoxicity-associated neuroinflammation involve mitochondrial DNA-mediated cGAS/STING axis: implication of Type-1 interferon response in cognitive impairment

• Published in: Molecular neurobiology 2024-09, Vol.61 (9), p.6217-6244
• Main Authors: Preeti, Kumari, Sood, Anika, Fernandes, Valencia, Khan, Islauddin, Khatri, Dharmendra Kumar, Singh, Shashi Bala
• Format: Article
• Language: English
• Subjects: Attention; Biomedical and Life Sciences; Biomedicine; Bovine serum albumin; CD16 antigen; Cell Biology; Cognitive ability; CXCL10 protein; Cytoplasm; Diabetes; Diabetes mellitus (non-insulin dependent); Glia; High fat diet; Immune response; Innate immunity; Interferon; Interferon regulatory factor; Interferon regulatory factor 3; Kinases; Metabolic disorders; Metabolic rate; Metabolism; Microglia; Mitochondrial DNA; Neurobiology; Neurology; Neurosciences; Palmitic acid; Postsynaptic density proteins; Selective media; Stat1 protein; Streptozocin; Synaptophysin; Tumor necrosis factor-α; β-Interferon
• ISSN: 0893-7648; 1559-1182; 1559-1182
• DOI: 10.1007/s12035-024-03933-y

Type-1 IFN (interferon)-associated innate immune response is increasingly getting attention in neurodegenerative and metabolic diseases like type 2 diabetes (T2DM). However, its significance in T2DM/lipotoxicity-induced neuroglia changes and cognitive impairment is missing. The present study aims to evaluate the involvement of cGAS (cyclic GMP-AMP synthase)-STING (stimulator of interferon gene), IRF3 (interferon regulatory factor-3), TBK (TANK binding kinase)-mediated Type-1 IFN response in the diabetic brain, and lipotoxicity (palmitate-bovine serum albumin conjugate/PA-BSA)-induced changes in cells (neuro2a and BV2). T2DM was induced in C57/BL6 mice by feeding on a high-fat diet (HFD, 60% Kcal) for 16 weeks and injecting a single dose of streptozotocin (100 mg/kg, i.p ) in the 12th week. Plasma biochemical parameter analysis, neurobehavioral assessment, protein expression, and quantitative polymerase chain reaction study were carried out to decipher the hypothesis. T2DM-associated metabolic and lipotoxic stress led to mitochondrial impairment causing leakage of mtDNA to the cytoplasm further commencing cGAS activation and its downstream signaling. The diseased hippocampus and cortex showed decreased expression of synaptophysin ( p