Abstract: Objective To screen the differential expression of apoptosis-related protein and stress response protein(APR-SRP)genes after human brain injury by cDNA microrarray.Methods The total RNAs were isolated from normal and injured brain tissues of a car-accident victim,and were purified to obtain mRNAs by Oligotex.Both mRNAs from the tissues of the injured and the normal tissue were reversely transcribed to cDNAs with the incorporation of fluorescent dUTP to prepare the hybridization probes.The probes from normal tissue was labeled with Cy3-dUTP,that from the injured tissue with Cy5-dUTP.The mixed probes were hybridized to the BioDoor Chip ARP-SRP-1.0S,a cDNA microarray which contains77apoptosis related protein genes and23stress protein related genes.After high-stringent washing,the cDNA microarray was scanned for the fluorescent signals and showed differences between two tissues.Results Among the100target genes,Only CLN2gene(Homo sapiens lysosomal pepstatin insensitive protease gene)showed distinct deference in expression level between the brain injury and normal tissues.Conclusion cDNA microarray analysis indicated that CLN2gene,which is correlated to a fatal childhood neurodegenerative disease,might be related to the brain injury.The expression level of CLN2gene was significantly decreased in brain injured tissue in comparison to normal tissue.Further analysis of this gene will be helpful to understand the molecular mechanism of brain injury and utilization in forensic medicine.

Key words: cDNA microarray, gene expression profiling, differential expression, brain injury