摘要
BACKGROUND：Various molecular mechanisms of cell death following traumatic brain injury have been previously described.However,the time course of cell death remains unclear.TUNEL and Fluoro-Jade B labeling have been widely used to label apoptotic cells and neuronal degeneration.Propidium iodide （PI） functions as a biomarker of cell death in vivo.OBJECTIVE：To explore the role of PI labeling compared to TUNEL and Fluoro-Jade B staining for detecting neural cell death,and to observe time course of traumatic brain injury-induced cell death in mice.DESIGN,TIME AND SETTING：A randomized,controlled,animal experiment was performed at the Laboratory of Aging and Nervous Diseases,Soochow University from September 2007 to December 2008.MATERIALS：PI （B1221） was purchased from Sigma,USA.TUNEL kit was purchased from Roche Molecular Biochemicals,USA.Fluoro-Jade B was purchased from Chemicon,USA.METHODS：A total of 70 healthy,male,Kunming mice were randomly assigned to sham-surgery （n = 5） and model （n = 65） groups.Traumatic brain injury was established using the controlled cortical impact method.PI was intraperitoneally injected at 1 hour prior to animal sacrifice.MAIN OUTCOME MEASURES：TUNEL,Fluoro-Jade B,and Pl-positive cells were quantified using a double-labeling method to determine the time course of traumatic brain injury-induced cell death.RESULTS：PI labeled cells in an earlier phase of cell death than TUNEL and Fluoro-Jade B labeling.Pl-positive cells were observed immediately following injury,and the numbers rapidly increased in injured brain areas at 1 hour,peaked at 24-48 hours,and subsequently decreased at 3-21 days post-injury.TUNEL-labeled cells were significantly increased at 12 hours,while Fluoro-Jade B-labeled cells were increased at 6 hours after injury,with cells still visible at 6-48 hours post-injury.Moreover,a greater number of Pl-positive cells were observed compared to TUNEL- and Fluoro-Jade B-labeled cells.CONCLUSION：PI labeling is more sensitive and reliable than TUNEL and Fluoro-Jade B staining for detecting cell death following traumatic brain injury.Moreover,PI labeling can function as a reliable marker to estimate the entire time course of cell death.
BACKGROUND：Various molecular mechanisms of cell death following traumatic brain injury have been previously described.However,the time course of cell death remains unclear.TUNEL and Fluoro-Jade B labeling have been widely used to label apoptotic cells and neuronal degeneration.Propidium iodide （PI） functions as a biomarker of cell death in vivo.OBJECTIVE：To explore the role of PI labeling compared to TUNEL and Fluoro-Jade B staining for detecting neural cell death,and to observe time course of traumatic brain injury-induced cell death in mice.DESIGN,TIME AND SETTING：A randomized,controlled,animal experiment was performed at the Laboratory of Aging and Nervous Diseases,Soochow University from September 2007 to December 2008.MATERIALS：PI （B1221） was purchased from Sigma,USA.TUNEL kit was purchased from Roche Molecular Biochemicals,USA.Fluoro-Jade B was purchased from Chemicon,USA.METHODS：A total of 70 healthy,male,Kunming mice were randomly assigned to sham-surgery （n = 5） and model （n = 65） groups.Traumatic brain injury was established using the controlled cortical impact method.PI was intraperitoneally injected at 1 hour prior to animal sacrifice.MAIN OUTCOME MEASURES：TUNEL,Fluoro-Jade B,and Pl-positive cells were quantified using a double-labeling method to determine the time course of traumatic brain injury-induced cell death.RESULTS：PI labeled cells in an earlier phase of cell death than TUNEL and Fluoro-Jade B labeling.Pl-positive cells were observed immediately following injury,and the numbers rapidly increased in injured brain areas at 1 hour,peaked at 24-48 hours,and subsequently decreased at 3-21 days post-injury.TUNEL-labeled cells were significantly increased at 12 hours,while Fluoro-Jade B-labeled cells were increased at 6 hours after injury,with cells still visible at 6-48 hours post-injury.Moreover,a greater number of Pl-positive cells were observed compared to TUNEL- and Fluoro-Jade B-labeled cells.CONCLUSION：PI labeling is more sensitive and reliable than TUNEL and Fluoro-Jade B staining for detecting cell death following traumatic brain injury.Moreover,PI labeling can function as a reliable marker to estimate the entire time course of cell death.
基金
the National Natural Science Foundation of China,No. 30571909,30872666,30870808
the Foundation of Shanghai Forensic Key Laboratory,No. KF0904
