Changes In Expression Profile Of Sub-Proteome In Rat Hippocampal CA1 Region After Forebain Ischemia

Changes in expression profiles of sub-proteome in rathippocampal CA1 region after forebrain ischemiaThe vulnerability of neurons to cerebral ischemia varies widely among different regions in the CNS. Different neuronal populations within a brain region, including hippocampus, also show different susceptibility to ischemic insult. Studies have shown that CA1 pyramidal neurons in hippocampus are particular vulnerable to ischemic insult and die 3-7 days after transient forebrain ischemia, whereas CA3 neurons are relatively resistant to transient ischemia and remain viable after such an insult, which had been clearly shown in Pulsinelli's 4-VO model accepted comprehensively. The mechanisms of this selective neuronal damage are not fully understood.During the pathological process of stroke, along with injury and death of cells, devourment and degradation of metabolic substances,and even endogenous regeneration, proteins-the direct executors oflife-tend to have variable changes in expression level andmodification status. In the other way, occurrence and development of stroke can be interfered by man-made protein metabolism. The above two points have been proven by a lot of researches on dozens of interesting proteins.These investigations are so artful, and have chosen different objects to elucidate mechanism of stroke. At the same time, they all have regrets if they wanted to take an overall view of the expression levels, modification status and interactions of maybe thousands of proteins engaged.As a brand-new subject and method flat, proteomics containingmultiple techniques can handle protein separation, identification and relative bioinformatics in much higher throughput than ever before. More than a thousand of protein spots can be shown on a well-separated plate gel, analyzed by professional software later, and further identified by N-terminal amino acid sequencing or modern bio-mass spectrometry. Then, a more powerful tool has emerged to help us survey on our issue again. Recently, proteomic method had already been successfully applied to animal models of Alzheimer's disease, epilepsy and aging, but not brain ischemia.To obtain the proteome profile for the hippocampal subregions, we established an improved microdissection method and sub-proteomic profiling analysis for CA1, CAS and dentate gyrus by using protein solubility-based sequential sample extraction followed by modified two-dimensional electrophoresis, which displays cytosolic or membrane proteins/peptides respectively.Based on the above method, we explored the proteomic change in CA1 subregions of rat hippocampus between sham-operation rats and rats subjected to 15 min 4-VO ischemia.After analyzing using professional software, we found 3 membrane protein spots disappeared, while 3 cytosolic protein spots were produced after ischemia-reperfusion, which represent proteins maybe involved in the mechanism of ischemic injury, and remaining further confirmed with identification of mass spectrometry and some other manners.At the same time, sequential extraction was proved to be a more effective way to show enriched membrane protein/peptides, which play important roles in cell events, such as signal transduction.