Testing The Expressions Of Tau Protein And Its Relevant Genes In The Brain Tissuses Of Intractable Eilepsy By Gene Microarray Scanning And Immunohistochemistry

Objective: The most evident pathologic alteration of intractableepilepsy is hippocampal mossy fiber sprouting. The primary physiologicrole of tau protein is to modulate neurite growth. This study was toinvestigate expression of tau protein in the brain tissue from patients withintractable epilepsy so as to explore the possible roles of tau protein in thepathogenesis of intractable epilepsy. Data and Methods: 48 patients were diagnosed as intractableepilepsy . The type of seizure in the patients was determined in accordancewith the International Classification of Epileptic Seizures specified by theInternational League Against Antiepilepsy in 1981. There were 25 malesand 23 females; their ages ranged from 8 to 44 years, with a mean of24.10±9.13 years (?X±S) years. 34 patients had generalized tonic-clonicseizures, 13 had complex partial seizures, and only 1 had simple partialseizures. A total of 48 control subjects were included in this study. Amongthem, 28 were males and 20 females, whose ages ranged from 11 to 42years with a mean of 25.69±8.17 years (?X±S). All controls were localresidents from Chongqing who died accidentally, such as from trafficaccidents during 2002 to 2004 and were autopsied legally. Operative specimens from the patients and those from the controlswere taken out from the bodies. Some tissues were immediately stored inliquid nitrogen for microarray scanning, and the others were fixed in 4%paraformaldehyde at 40C for 48h and embedded conventionally in paraffin.Immunohistochemistry is used to test the tissue's Tau protein andphosphorylated tau protein; the computer graphic Analysis System is usedto test the optical density which is expressed as mean ± SD(?X±S)andtested via t-test. Results: 1. Gene Microarray Scanning:There is no distinct difference betweenthe gene expressions of Tau protein in the brain tissues of the control groupand in those of the intractable epilepsy group (Cy5/Cy3=0.640). However,the gene expressions of zymogram that is relevant to Tau proteinphosphorylation present obvious difference. 2.Tau protein expression : With immunohistochemistry, tau proteinstaining has been found to be evident in hippocampal tissue and temporallobe neurons in intractable epilepsy group. It's the same with the controlgroup. There are no significant differences in tau protein expression inhippocampal tissue and temporal lobe neurons between two groups(p>0.05). 3.Phosphorylated tau protein expression : With immunohistochemis-try, in intractable epilepsy group, phosphorylated tau protein staining isevident in the hippocampal tissue and temporal lobe neurons. However, it isnot so evident in those areas in the control group. There are significantdifferences between phosphorylated tau protein expression of both groups(p<0.05). Conclusions: 1.While screening the gene changes of intractable epilepsy, genemicroarray is characterized by high speed, large capacity and high agility.Because gene microarray maybe results in pseudo-positive andpseudo-negative findings, we should use other method to verify itsresult ,such as immunohistochemistry. 2.The most evident pathologic trait of intractable epilepsy ishippocampal mossy fiber sprouting. Hippocampal mossy fiber sproutingare associated with upregulated expression of phosphorylated tau protein,an event that may be a crucial factor in hippocampal synapticreorganization in patients with intractable epilepsy. 3.Changing the phenotype of Tau protein will probably determine theprognosi of intractable epilepsy patients,which provides us an effectivetheoretical evidence for the improvement of treating intractable epilepsy.