Fig. 5: Specific STING upregulation in microglia aggravated infarct volume and promoted M1 microglia polarization after ischemic stroke.

a AAV-NC or AAV-STING (green) co-stained with Iba1 (blue) and STING (red) 3 days post-MCAO in mice receiving EGFP-conjugated adeno-associated virus (AAV). b Representative TTC staining indicating ischemic infarct volume and brain edema in WT or STING^−/− MCAO mice injected with AAV-NC or AAV-STING. c The mNSS of WT MCAO, and STING^−/− MCAO mice injected with AAV-NC or AAV-STING. d Rotarod assessment of WT and STING^−/− mice receiving EGFP-conjugated AAV. Mice were tested before MCAO surgery. e TUNEL/NeuN staining in the peri-infarct area and quantitative analysis. Scale bar = 100 μm. f Immunoblotting image of microglial phenotype markers in WT or STING^−/− MCAO mice receiving AAV, with quantification. g qRT-PCR analyses of mRNA expressions of pro-inflammatory and anti-inflammatory factors in mice receiving AAV injection. h Representative photographs and quantitative analysis of microglial polarization at the cortex and striatum of the perilesional site by triple immunostaining. Data are expressed as mean ± SD. n = 6. Scale bar = 50 μm. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001 vs AAV-NC infected WT MCAO animals. ^#P < 0.05, ^##P < 0. 01, ^###P < 0.001 vs AAV-NC infected STING^−/− MCAO animals.