Effects Of Emodin On The Apoptosis Of PMN In SIRS

Background and objective:Systemic inflammatory response syndrome (SIRS) is a systemic manifestation of nonspecific infection. Over inflammatory reaction is the pathologic basic that damage cell, tissue or organ. Consquently, SIRS is considered as the prophase of multiple organ dysfunction syndrome (MODS). Polymorphonuclear neutrophil (PMN) is the main effector cell in the process of inflammatory, for which it is the first line of defense system that the host antagonizes inflammatory or nonself matter, and plays an important role in occurrence, development and turnover of inflammation. Under the normal condition, PMN will be cleaned by macrophage phagocytosis after apoptosis. If the apoptosis of PMN is delayed, effective time of PMN is not only extended, but also resulting in inflammasomeformation ----an essential process leading to the secretion of considerable proinflammatory cytokines, which make inflammatory response amplified gradually. The apoptosis of PMN is considered as an important mechanism by which inflammatory response recovers. Rhubarb is a critical composition of many traditional Chinese medical prescription. In clinic, it contributes to improve the patients with SIRS. Moreover, recently studies have implicated that Emodin which is the important composition Rhubarb can promote the apoptosis of PMN from the patients with SIRS. In this study, the aim is to investigate the influences and its mechanisms of Emodin on apoptosis of PMN from patients with SIRS.Methods:Collecting of peripheral vein blood in patients with SIRS and healthy volunteers. Isolation and culture neutrophils from peripheral blood in vitro. There are five groups in our study: PMN from healthy volunteers, Emodin were used on the PMN from healthy volunteers, PMNfrom SIRS patients, Emodin and Caspase-9 inhibitor combined with Emodin were used on the PMN from SIRS patients separately. Following 24 hours of in vitro culture, the apoptosis of PMN was assessed by flow-cytometry analysis. The expression of Bax/Bcl-xL mRNA is detected by using RT-PCR. The expression of Bax/Bcl-xL protein is detected by using immunocytochemistry.Results:①Flow-cytometry: The percentage of PMN apoptosis in patients with SIRS is significantly lower than healthy volunteer(16.36±4.56 vs 62.89±9.41, P<0.05). Treatement of PMN from volunteers with Emodin, the percentage of apoptosis was not obviously variance(62.89±9.41 vs 67.15±7.57, P﹥0.05). Nonetheless, compared with SIRS group, the percentage of PMN apoptosis significantly increased in Emodin-treated group(29.12±9.67 vs 16.36±4.56, P<0.05). Compared with Emodin-treated group, the percentage of PMN apoptosis significantly decreased in Caspase-9 inhibitor combined with Emodin treated group(16.43±8.22 vs 29.12±9.67, P<0.05).②Compared with healthy volunteers, the expression of Bax which is the proapoptotic gene was not obviously different in the PMN from the patients in SIRS(mRNA level: 1.13±0.08 vs 1.28±0.13, P﹥0.05, protein level: 62.5% vs 80.0%, P﹥0.05), however, the expression of antiapoptotic gene Bcl-xL significantly increased in the PMN from the patients with SIRS(mRNA level: 0.98±0.12 vs 0.32±0.07, P<0.05, protein level: 87.5% vs 20.0%,P<0.05). In the patients with SIRS, compared with control group, the expression of Bax was not markedly different in Emodin treated group(mRNA level: 1.19±0.11 vs 1.13±0.08, P﹥0.05, protein level: 87.5% vs 62.5%, P﹥0.05). But between the two group, the expression of Bcl-xL significantly differ(mRNA level: 0.39±0.06 vs 0.98±0.12, P<0.05, protein level: 25.0% vs 87.5%, P<0.05).Conclusion: The apoptosis of PMN in patients with SIRS shows profoundly delayed compared with the apoptosis of PMN in healthy volunteers. Emodin has no obvious effect on the apoptosis of PMN in healthy volunteers, nevertheless, Emodin can significantly inhibit the delay of PMN apoptosis in patients with SIRS. Caspase-9 inhibitor can degrade the contribution that Emodin induce the apoptosis of PMN in patients with SIRS, and Emodin can make the percentage of anti/pro-apoptotic geneBcl-xL/Bax which is augmented in PMN from the patients with SIRS. These are implied the effect of that Emodin induces apoptosis of PMN maybe come true by the mitochondrial pathway of cell apoptosis.