Expression and role of bone morphogenetic protein receptor II in focal cortical dysplasia

Abstract

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. Key words: Bone morphogenetic protein receptors, type Ⅱ ; Epilepsy; Malformations of cortical development