A Study Of Early Apoptosis And Caspase-10 Expression In Brain Tissue Of Rats With Fluid Percussion Injury

Serious traumatic brain injury(TBI) is one of the most concerned problems in neurosurgical fields because of its high mortality and disability ratio.There is no significant progress to cure TBI,since the mechanism of TBI still remains unkown. Based on lateral fluid percussion injury,by means of the flow cytometer ,marked with Annexin V-FITC, and electron microscope, the modality of early apoptotic and apoptotic nerve cells and theirs changes over time after lateral fluid percussion injury were measured. Simultaneously, By means of real-time PCR , dynamic process of caspase-10 expression difference was quantitatively observed,aiming at knowing more about the mechanism of action of Caspase-10 in nerve cells'apoptosis after TBI.Part I Early apoptosis of nerve cells in rat's left parietal cortex after traumatic brain injuryObjective To observe early apoptosis and its dynamic changes over time after traumatic brain injury(TBI) in Sprague-Dawley rats. Methods By means of the flow cytometer and electron microscope, the ratio of apoptotic nerve cells and its change over time after lateral fluid percussion injury were measured. Results The results of flow cytometer showed that the early apoptosis of nerve cells occurred in left parietal cortex 6 hours after TBI with a percentage of 21.97%(p<0.01). The ratio of early apoptosis got to its peak ( up to 65.90% ) 24 hours after TBI(p<0.01). There was no significant difference between 24 hours and 48 hours after TBI in the ratio of apoptotic nerve cells(p>0.05). Electron microscope showed that early apoptosis of nerve cells occurred in left parietal cortex 24 hours after TBI. Conclusion Early apoptosis of nerve cells in left parietal cortex occurs 6 hours after TBI, which is earlier than that of conventionally reported.Part II Analysis of caspase-10 expression difference after TBI.Objective: Dynamic process of caspase-10 expression difference was quantitatively observed,aiming at knowing more about the mechanism of action of caspase-10 in nerve cells'apoptosis after TBI. Methods Based on lateral fluid percussion injury,by means of quantitative real-time PCR,dynamic process of caspase-10 expression difference was quantitatively observed. Results Conclusion The results of quantitative real-time PCR showed that up-regulation of caspase-10 of nerve cells occurred in S-D rats'left parietal cortex at groups of 6 hours(2969.53±1217.08) after TBI, dropped to normal level at groups of 48 hours (494.11±261.96). However,there were no effects found on the opposite sides. Conclusion we first find that up-regulation of caspase-10 of nerve cells occurred in S-D rats'left parietal cortex at groups of 6 hours, earlier than up-regulation of Caspase-3 at groups of 48 hours(0.49±0.22)after TBI, roughly simultaneously occurred comparing with Caspase-8 ( 0.12±0.03 ) , which is conventionally reported..