Emodin On Mitochondrial Apoptosis Pathway Of PMN In SIRS Rat Model Of Severe Acute Pancreatitis In Vitro

Objective:Severe acute pancreatitis (SAP), which sudden onset, rapid progressing and more complications, is common reason for the systemic inflammatory response syndrome (SIRS). SIRS is early stage of multiple organ dysfunction syndrome (MODS) caused by lots of ills. Once MODS occur, treatment will be difficult, the costs and mortality will be greatly increased. Therefore, blocking SIRS progress to the MODS is the key to lower mortality of SAP. Polymorphonuclear neutrophils(PMN), which plays a key role in happening, development and prognosis of inflammation, is an important indicator of inflammatory response. Recent study suggests that delayed or impaired apoptosis of PMN contributes to the progression of pathophysiological feature of SIRS. There are two main ways to apoptosis of PMN:first, the death receptor pathway; second, mitochondria mediated pathway. Mitochondrion, which plays an important role in the regulation of apoptosis, is called "initiator", "amplifiers". Mitochondrial Cytochrome c (Cyt-c) is an important apoptotic protein and plays a pivotal role in mitochondria mediated pathway.In this study, the aim is to study the exosomatic function of Emodin and Dexamethasone to SIRS in SAP through making the SIRS SD rat model. Mitochondrial Cyt-c, as a starting point, will be included in studying the molecular mechanisms of abnormal neutrophil apoptosis in SIRS. To study the target point of Emodin and Dexamethasone in the therapy of SAP as well. Those studies may provide a theoretical basis for therapy of SAP.Method:The SIRS model of SD rat was established by retrograde injection of 1.5% sodium deoxycholate into common biliopancreatic duct. Preparation of animal model:20 SD rats were randomly divided into 2 groups, that is, sham operation group (SO group), model group of SIRS in SAP (SIRS group), and 10 SD rats each group. Experiment of intervention in vitro:24 hours after the modeling, PMN, which was separated from SO group and SIRS group, was divided into 4 groups. That is Drug blank control group (CON group), Dexamethasone intervention group (DEX group), Emodin intervention group (EMO group), Dexamethasone associate with Emodin intervention group (DAE group).24 hours after drug intervention, the mitochondrial membrane potential and the expression of Cyt-c were observed from PMN which was collected by every group.Results:1. Mitochondrial membrane potential:(1)SIRS group:Compared with the CON group, the mitochondrial membrane potential of DEX group, EMO group, DAE group was significantly lower, in which the lowest was DEX group (P<0.01). There was no obviously difference between DAE group and EMO group (P> 0.05).(2)SO group:The mitochondrial membrane potential of every intervention drug group, in which the lowest was DEX group, was lower than CON group (P<0.01). Compared with DAE group, the mitochondrial membrane potential of EMO group was not significantly different (P> 0.05).(3)Under the same intervention compared SO group with SIRS group: The mitochondrial membrane potential in SIRS group was significantly lower than SO group (P<0.01) under the same intervention, while the two CON groups had no significant difference (P> 0.05).2. Expression of mitochondrial Cyt-c:(1) SIRS group:Mitochondrial Cyt-c expressed in every drug intervention group, in which the highest was DEX group, the lowest was CON group, and EMO group had the same expression with DAE group. The expression of mitochondrial Cyt-c was significantly higher (P<0.01) in DEX group, EMO group and DAE group compared with CON group.(2) SO group:The mitochondrial Cyt-c was not found in SO group.Conclusion:1. Emodin, Dexamethasone can decrease the mitochondrial membrane potential of PMN in SIRS rat model of severe acute pancreatitis in vitro.2. Emodin, Dexamethasone can promote the mitochondrial Cyt-c of PMN in SIRS rat model of severe acute pancreatitis release in vitro.3. Emodin, dexamethasone can promote or induce delayed PMN apoptosis in SIRS rat model of severe acute pancreatitis through mitochon-dria mediated apoptotic pathway possibly.4. Emodin and Dexamethasone did not show synergy in promoting PMN apoptosis in SIRS rat model of severe acute pancreatitis in vitro.