Study On Mechanisms Of Mitochondria In Lymphocyte Apoptosis Of Sepesis

Objective:The latest research show that lots of lymphocyte apoptosis play an important roles in sepsis immune suppression. Mitochrodrial signal pathway is most general in apoptosis of sarcode. This study was undertaken by using the mouse splenic lymphocyte to investigate cell apoptosis, mitochondrial membrane potential, cytochrome C and research mechanisms of mitochondria in lymphocyte apoptosis of sepsisMethods:In our research , female C57BL/6 mice whose body weight ranged from 17 to 25 grams were utilized and assigned randomly to three groups: sham operated group (Control), cecal ligation and puncture group (CLP) . The present study was undertaken by using the mice splenic lymphocyte to investigate cell apoptosis, mitochondrial membrane potential, cytochrome C. The apoptosis alteration was evaluated by Annexin V-FITC/PI double staining using flow cytometry. The alteration of mitochondrial membrane potential was investigated by Rhodamine-123 staining of cells. Cytochrome C of mitochodial and cytosol was investigated by Western-blot methods. Statistical analysis was performed using SPSS11.5 for windows software. Experiment data was indicated with mean±standard.Results:1. Affirmation of the succeeded CLP modelAfter operation, the mice in CLP group appearance depressed, drowsiness, clumsy, loss of appetite and so on. But control group have the same appearance before or after operation. In CLP group 24 hours survival rate was 80%, 72 hours crude mortality ratio was 45～55%. No mice were dead in control group. Different extent injury in the pathological section examination about liver, lung, bowels, spleen has happened in the CLP group. Comparing with CLP group, no obviously inflammation was found in control group.2. The alteration of splenic lymphocyte apoptosisThe CLP group increase apoptosis of splenic lymphocyte apoptosis. Comparison between sham and CLP group has statistical significance. (P<0.05). This result show that lymphocyte apoptosis is obvious in sepsis.3.The changes of mitochondrial membrane potentialThe Rhodamine-123 fluorescent intensity in splenic lymphocyte apoptosis is reduced in CLP group. Comparison between sham and CLP group has statistical significance. (P<0.05). This result show that mitochrodrail membrane potential can degrade in lymphocyte apoptosis.4. The changes of cytochrome CApoptosis can induce mitochondrial cytochrome C release into cytoplasm. In the CLP group, elevation of cytochrome C in cytosol is concurrently in accordance with decline in mitochondrial cytochrome C content.Conclusion:1 The mouse model by sepsis can be established successfully by the method CLP for experimental observation.2. The spleen is one of the target organs in MODS by sepsis, spleen lymphocyte apoptosis is the main change of injury encountered in sepsis. The extensive apoptosis of splenic lymphocytes may be the major cause of immune suppression in the disorder that occurs in sepsis.3. We find that the reduction of mitochondrial membrane potential can be detected in mouse sepsis model and elevation of cytochrome C in cytosol is concurrently in accordance with decline in mitochondrial cytochrome C content. These data suggest that mitochondium and mitochondria signal pathway play an important role in lymphocyte apoptosis of sepsis.