Effect of M1 microglial polarization on secondary damage in the thalamus after cerebral cortical infarction

SHI Zhe; ZUO Xialin; PENG Linhui; LU Zhiwei; LI Kongping

doi:10.3969/j.issn.1006-5725.2024.22.004

Abstract：Objective To explore the effects of M1 polarization of microglia on secondary damage in the thalamus after cerebral cortical infarction.Methods A focal cortical infarct model of adult male SD rats was pre-pared using eletrocoagulation and randomized into Sham and model groups at different time points 1～4 weeks after surgery.Based on the assessment of neurofunctional changes in each group of rats,immunohistochemistry was used to observe the number and morphology of NeuN,GFAP and Iba-1 positive cells in(Ventral posterior nucleus of thalamus,VPN)of the ipsilateral thalamus after distal middle cerebral artery occlusion(dMCAO).Immunofures-cence was used to detect the number and morphology of M1 microglia marker(Iba-1+/CD68+cells)and M2 microg-lia marker(Iba-1+/CD206+cells)in VPN of the ipsilateral thalamus after dMCAO.Western blot was used to detect the expression levels of IL-1β,TNF-α,IL-10 and Arg-1 in VPN of the ipsilateral thalamus after dMCAO.Results The results of immunohistochemistry showed a significant decrease in NeuN positive cells and an increase in the density of GFAP and Iba-1 in the ipsilateral VPN of rats after dMCAO when compared with Sham group(P<0.001).Compared with sham group,the protein levels of TNF α and IL-1β were elevated in the ipsilateral VPN elevated(P<0.05).In addition,the model group rats exhibited higher Bederson scores,beam-walking test and adhesive removal test scores after dMCAO compared with Sham group(P<0.05).The numbers of M1 microglia marker(Iba-1+/CD68+cells)were significantly increased when compared with M2 microglia marker(Iba-1+/CD206+cells)in ipsilateral VPN of rats after dMCAO.Conclusion M1 polarization of microglia may play an essential role in secondary damage of thalamus after cerebral cortical infarction.