title: Increased expression of matrix metalloproteinase 9 in cortical lesions from patients with focal cortical dysplasia type IIb and tuberous sclerosis complex.
abstract: The malformative cortical lesions in the cerebral cortex that are characteristic of focal cortical dysplasia type IIb (FCDIIb) and tuberous sclerosis complex (TSC) are well-recognized causes of chronic intractable epilepsy in children. Increasing evidence suggests that extracellular matrix molecules play important roles in epileptogenesis. Matrix metalloproteinase 9 (MMP9), a typical extracellular matrix proteolytic protease, has been shown to participate in the occurrence of seizures in experimental models. In the present study, we used immunoblotting to analyze the levels of MMP9 protein in FCDIIb lesions, TSC tubers and control samples, which included epileptic neocortices from temporal lobe epilepsy and non-epileptic normal cortices (CTX). The cellular distribution of MMP9 was further investigated by immunohistochemical methods. Our findings demonstrated the elevated levels of the inactive and active forms of MMP9 protein in FCDIIb and TSC lesions compared with CTX. Furthermore, the immunohistochemical results showed that MMP9 was characteristically expressed in the following misshapen cells: hypertrophic neurons, dysmorphic neurons, balloon cells and giant cells. Additionally, double immunofluorescent staining revealed that the reactive astrocytes, but not the microglia, expressed high levels of MMP9. Taken together, our findings suggest that the overexpression and spatial distribution patterns of MMP9 may be linked with the intractable epilepsy caused by FCDIIb and TSC.
authors.affiliation: Epilepsy Research Center of PLA, Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.forename: Sixun
authors.initials: S
authors.lastname: Yu
authors.forename: Chunqing
authors.initials: C
authors.lastname: Zhang
authors.forename: Haifeng
authors.initials: H
authors.lastname: Shu
authors.forename: Shiyong
authors.initials: S
authors.lastname: Liu
authors.forename: Ning
authors.initials: N
authors.lastname: An
authors.forename: Meihua
authors.initials: M
authors.lastname: Yang
authors.forename: Qing
authors.initials: Q
authors.lastname: Yin
authors.forename: Hui
authors.initials: H
authors.lastname: Yang
mesh_terms: D001253:Astrocytes / Q000201:enzymology / Q000473:pathology; D001927:Brain Diseases / Q000150:complications / Q000201:enzymology* / Q000473:pathology; D002540:Cerebral Cortex / Q000201:enzymology* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004827:Epilepsy / Q000201:enzymology / Q000209:etiology / Q000473:pathology; D005260:Female; D015726:Giant Cells / Q000201:enzymology / Q000473:pathology; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007223:Infant; D008297:Male; D054220:Malformations of Cortical Development / Q000150:complications / Q000201:enzymology* / Q000473:pathology; D065703:Malformations of Cortical Development, Group I; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D009474:Neurons / Q000201:enzymology / Q000473:pathology; D014402:Tuberous Sclerosis / Q000150:complications / Q000201:enzymology* / Q000473:pathology
chemical_list: D005904:Glial Fibrillary Acidic Protein; D020780:Matrix Metalloproteinase 9