Résumé
Objective: To establish the stable methodology for screening antagonists of CD88, one of C5a receptors. Methods: Whole blood from volunteers was collected and then stimulated by C5a with different concentration for 10-30 min in the presence or absence of PMX-53 and LPS. Flow cytometry was used to detect the expression of CD11b which on the surface of neutrophil. Other functions of nentrophil, including lysozyme release, oxidative burst and interleukin (IL)-8 production, were also examined respectively. Finally, western blotting was used to detect the content of total and phosphorylated ERK and AKT. Thus, the effects about C5a receptor stimulant and the positive medicine PMX-53 on biochemical indicators were investigated. Results: The C5a stimulation actively up-regulated CD11b expression, evoked lysozyme and reactive oxygen species release, increased the IL-8 production and the contents of total and phosphorylated ERK/AKT. While the positive medicine PMX-53 significantly blocked these effects. Conclusion: The methodology in vitro for screening C5a receptor antagonists inhuman whole blood is successfully established.
Résumé
Objective To investigate effects of complement C5a receptor and P38-MAPK on myocardial injury brought about by septic shock in rats. Method The early septic shock models were established by the method of cecal ligature and incision (CLI). A total of 30 Sprague-Dawley rats were randomly( random number) divided into normal control group ( n = 6 ) and model group ( n = 24 ) and the model group was further 12 hours later divided into 12 h subgroup (n = 12) and 24 h subgroup (n = 12). The arterial blood samples were collected 12 hours later for detecting the levels of lactate dehydrogenase (LDH) and creatine kinase (CK), and then the rats were sacrificed and the myocardial tissues were taken to assay the expressions of C5a receptor and P38-MAPK by using immunohistochemistry after HE staining. And the above procedure as did in 12 h subgroup was done 24 hours later. Results Compared with the control group, the levels of LDH and CK in rats of Model group were significantly higher (P ＜ 0. 05). There were significant differences in LDH and CK between 24 h subgroup and 12 h subgroup [(2 568.9 ± 280) vs. (2 201.2 ± 149)] and [(5 029.7±458) vs. (2 629.4±140)] ,P＜0. 05, P＜0.05. The analysis of C5aR and P38-MAPK gray values showed that there were significant differences between the model group and normal control group [(702.77 ±122) vs. (388.36±113)], P＜0. 05 and [(646.40±181) vs. (307.32 ±61)] ,P＜0.05,and those differences also found between the 24 h subgroup and 12 h subgroup. There was a significant positive correlation between C5aR and P38-MAPK (P＜0.05 ), and also the P38-MAPK had significant positive relationships with LDH(P＜0.05) and CK (P＜0.05). Conclusions The C5aR strongly potentiates the P38-MAPK to induce myocardial injury by septic shock.
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As one of the most important products of complement activation, C5a, after binding to ts receptors (C5aR), has been considered to be involved n the pathology of numerous inflammatory diseases, such as acute ung njury, sepsis, rheumatoid arthritis and glomerular nephritis. Therefore, the focus of current studies on how to block C5a and C5aR signal transduction for dampening the inflammatory reaction. Recently, several antagonists of C5a and C5aR were reported, including C5a antibody, small molecule human C5aR antagonists, C5a antisense peptide, C5a mutant and the complex of chemotaxis inhibitory protein of Staphylococcus aureus with C5aR. In this review, the structure and function of C5a and C5aR, and the advances n the research on their antagonists are summarized.
Résumé
Objective:To discover some high hydrophilic profiles of the human C5a anaphylatoxin based on relationship between the structure and function of the protein and the protein molecular design principles.Methods:The peptides were synthesized by 431A automatic peptide synthesizer,purified by PHLC and confirmed by caplilliary electrophoresis.Results:The N terminus No.9 30 profile of the C5aR(P22) could interacte with anti C5aR McAb(S5/1,from Serotic Co.),as determined by ELISA.Furthermore,it could be inhibited OD490 values remarkably by 10.0 ?g/L rhC5a(P