ABSTRACT
【Objective】 To observe the reactive change of cortical perivascular cells after craniocerebral injury and explore its mechanism. 【Methods】 The controllable cortical impact animal model was used to simulate craniocerebral injury, the expressions of cortical pericyte markers at different time points after trauma were studied by Western blotting, and the biological behavior of vascular pericytes after craniocerebral injury was determined by transmission electron microscopy. Post-traumatic high mobility group box 1 (HMGB1), receptor for advanced glycation end product (RAGE), and nuclear factor κB (NF-κB) were detected by Western blotting. The experimental animals were divided into FPS-ZM1 (a specific RAGE receptor blocker) injection group and wild-type group. Wet and dry brain weight and transmission electron microscopy were used to study the post-traumatic effects of HMGB1-RAGE on pericytes. The primary mouse brain microvascular pericytes were cultured and supplemented with HMGB1 recombinant protein; the cultured pericytes supplemented with FPS-ZM1 were used as the control to explore the effect of HMGB1-RAGE pathway on vascular pericytes in vitro. 【Results】 The expression levels of early post-traumatic cortical pericyte markers platelet-derived growth factor receptor beta (PDGFR-β) and NG2 proteoglycan (NG2) decreased (PDGFR-β, Control vs. CCI 3D P<0.05; NG2, Control vs. CCI 6H P<0.05; Control vs. CCI 1D P<0.05). We found that pericytes were detached from blood vessels, accompanied by local blood-brain barrier opening. The expression of HMGB1-RAGE-NF-κB signaling pathway was increased in the early cortex after trauma (HMGB1, Control vs. CCI 6H P<0.05, Control vs. CCI 1D P<0.05; RAGE, Control vs. CCI 6H P<0.05, Control vs. CCI 1D P<0.05, Control vs. CCI 3D P<0.05, Control vs. CCI 5D P<0.05, Control vs. CCI 7D P<0.05; NF-κB, Control vs. CCI 6H P<0.05, Control vs. CCI 1D P<0.05). After blocking the binding of RAGE with the ligand, cortical edema was reduced (CCI 6H P<0.05, CCI 1D P<0.05), and neurovascular unit damage was reduced. HMGB1 recombinant protein could increase the migration ability of cultured pericytes (Control vs. HMGB1 P<0.05, Control vs. HMGB1+FPS-ZM1 P<0.05), and could be reversed by FPS-ZM1 (HMGB1 vs. HMGB1+FPS-ZM1 P<0.05). 【Conclusion】 High-level HMGB1 after traumatic brain injury mediates pericytes’ detachment from blood vessels through RAGE on pericytes and leads to the occurrence of local cerebral edema.