RESUMO
【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.
RESUMO
The myelin-associated protein Nogo-A was considered to be the axon growth inhibitory factor, which participates in a variety of pathophysiological regulation of nervous system. In recent years, a growing number of studies have shown that Nogo-A protein is closely related to epilepsy by regulating dendritic plasticity, mediating abnormal nerve migration and regulating glial cell activation, etc. This article will review the research progress of Nogo-A in epilepsy in recent years.
RESUMO
Objective To detect the expression of bone morphogenetic protein receptor Ⅱ ( BMPR Ⅱ ) in human focal cortical dysplasia ( FCD Ⅱ b). Methods Fourteen specimens of FCD Ⅱ b surgically removed and pathologically verified were collected from June 2008 to June 2010 and the expression of BMPR Ⅱ in the normal brain tissues and the pathological specimens was detected by means of immunohistochemistry and western blot. Results In the normal brain tissues, BMPR Ⅱ was widely expressed in the cortical neurons of the grey matter, with no positive immunostaining in the white matter. In the cortical lesion of FCD Ⅱ b, BMPR Ⅱ was strongly expressed in the misshapen cells including balloon cells (BCs) , dysmorphic neurons (DNs) and giant neurons (GNs). Positive BMPR Ⅱ expression was also observed in the reactive astroeytes and low level expression of BMPR Ⅱ was found in the normal-appearing (NA) neurons. Western-blot analysis showed that BMPR Ⅱ expression tended to be lowered in the FCD Ⅱ b specimens compared with the normal brain tissues ( P < 0. 05 ). Conclusion The expression of BMPR Ⅱ is altered and reduced in the FCD Ⅱ b, suggesting that BMP signal pathway may participate in the pathogenesis of FCD.