Extracellular matrix protein SC1/hevin in the hippocampus following pilocarpine-induced status epilepticus.
Pilocarpine-induced status epilepticus (SE) mimics many features of temporal lobe epilepsy and is a useful model to study neural changes that result from prolonged seizure activity. In this study, distribution of the anti-adhesive extracellular matrix protein SC1 was examined in the rat hippocampus following SE. Western blotting showed decreased levels of SC1 protein in the week following SE. Immunohistochemistry demonstrated that the decrease in overall SC1 protein levels was reflected by a reduction of SC1 signal in granule cells of the dentate gyrus. Interestingly, levels of SC1 protein in neurons of the seizure-resistant CA2 sector of the hippocampus did not change throughout the seizure time course. However, at 1 day post-SE, a subset of neurons of the hippocampal CA1, CA3, and hilar regions, which are noted for extensive neuronal degeneration after SE, exhibited a transient increase in SC1 signal. Neurons exhibiting enhanced SC1 signal were not detected at 7 days post-SE. The cellular stress response was also examined. A prominent induction of heat-shock protein (Hsp70) and Hsp27 was detected following SE, while levels of constitutively expressed Hsp40, Hsp90, Hsp110, and Hsc70 showed little change at the time points examined. The subset of neurons that demonstrated a transient increase in SC1 colocalized with the cellular stress marker Hsp70, the degeneration marker Fluoro-Jade B, and the neuron activity marker activity-regulated cytoskeleton-associated protein (Arc). Taken together, these findings suggest that SC1 may be a component of the 'matrix response' involved in remodeling events associated with neuronal degeneration following neural injury.
Lively
Starlee
S
Center for the Neurobiology of Stress, University of Toronto at Scarborough, Toronto, Ontario, Canada.
Brown
Ian R
IR
D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D004195:Disease Models, Animal; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005452:Fluoresceins; D055551:HSP27 Heat-Shock Proteins / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology; D008297:Male; D009930:Organic Chemicals / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D010862:Pilocarpine; D017966:Pyramidal Cells / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013226:Status Epilepticus / Q000139:chemically induced / Q000503:physiopathology*; D013997:Time Factors
D002135:Calcium-Binding Proteins; D016326:Extracellular Matrix Proteins; D005452:Fluoresceins; D055551:HSP27 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D009930:Organic Chemicals; C503128:Sparcl1 protein, rat; C435731:fluoro jade; D010862:Pilocarpine; D010751:Phosphopyruvate Hydratase