Research progress of C5a receptor C5AR1 in tumorgenesis and tumor development and immunotherapy / 中国肿瘤生物治疗杂志

@#[摘 要] C5AR1是补体激活片段C5a的受体，主要在粒细胞、单核细胞、树突状细胞和髓源性抑制细胞（MDSC）以及肿瘤细胞上表达。C5a可以刺激中性粒细胞产生炎性介质，也可以募集MDSC等免疫抑制细胞形成免疫抑制微环境，促进肿瘤的生长和转移，从而在肿瘤的发生发展中起到重要的作用。C5AR1已成为肿瘤治疗的新靶点，C5AR1靶向药与免疫检查点抑制剂联用能够起到协同抑制肿瘤的作用。就C5AR1的基本信息，促进肿瘤发生、生长和转移的机制，以及以C5AR1为靶点的抗肿瘤药的开发现状进行综述，以期为后续的机制研究、药物开发提供参考。

Role of C5a/C5aR1 pathway in imiquimod-induced chronic psoriasis skin inflammation and the underlying mechanism / 中华微生物学和免疫学杂志

Objective:To establish a mouse model of imiquimod (IMQ)-induced chronic psoriasis skin inflammation and to investigate the role of C5a/C5aR1 pathway in this process and the underlying mechanism.Methods:BALB/c mice were treated with IMQ cream or Vasline cream (control group) every other day for eight times to mimic the chronic skin inflammation. Psoriatic skin inflammation and pathological changes in the wild-type (C5aR1 + /+ ) mice and the mice with C5aR1 gene deletion (C5aR1 -/-) were monitored and analyzed. Epidermal proliferation (Ki67), keratin 6/14 expression and neutrophil infiltration in the skin lesions were observed with immunohistochemical (IHC) staining. qRCR was used to detect the expression of keratin 6/14 and related inflammatory cytokines. Flow cytometry was performed to measure the percentages of leukocytes, CD3 + T cells and IL-17A + γδTCR + T cells in local skin samples as well as IL-17A responses in draining lymph nodes. Results:IMQ treatment induced typical psoriatic skin inflammation, including scaling, erythema and thickness. Dysregulated epidermal proliferation, acanthosis, micro-abscesses, inflammatory cell infiltration and abnormal hyperplasia of dermal capillaries were observed after HE staining. Compared with the C5aR1 + /+ mice, the C5aR1 -/- mice showed significantly attenuated chronic skin inflammation, evidenced by decreased epidermal proliferation, down-regulated keratin 6/14 expression and alleviated neutrophil infiltration. Results of qPCR also indicated decreased expression of keratin 6/14, inflammatory cytokines (IFN-γ, MIP-1α, IL-1β and TNF-α) and IL-17-related cytokines (IL-6, IL-17A and IL-23) in skin samples of C5aR1 -/- mice. Moreover, the infiltration of leukocytes (CD45), CD3 + T cells and IL-17A + γδTCR + T cells in skin lesions as well as the percentages of IL-17A + , IL-17A + CD3 + T and IL-17A + γδTCR + T cells in draining lymph nodes were also decreased in C5aR1 -/- mice. Conclusions:This study suggested that IMQ treatment could induce chronic psoriasis skin inflammation in mice. C5a/C5aR1 signaling pathway mediates IMQ induced chronic skin inflammation via activating IL-17 producing cells. Targeting C5a/C5aR pathway would be a new strategy for the management of psoriasis.

The expression and clinical significance of neutrophil myeloperoxidase in patients with myeloperoxidase-antineutrophil cytoplasmic antibody associated vasculitis / 中华内科杂志

Objective:To investigate the expression and clinical significance of neutrophil myeloperoxidase (MPO) in patients with MPO-antibody associated vasculitis (AAV).Methods:Thirty-six newly diagnosed MPO-AAV patients who were hospitalized in the First Affiliated Hospital, Anhui Medical University from July 2018 to June 2021 were enrolled,and 36 age and sex matched healthy subjects were selected as controls. Neutrophil MPO level was detected by flow cytometry (FCM) and MPO mRNA was tested by real time quantitative polymerase chain reaction (RT-qPCR) in all subjects. Serum complement fragment C5 (C5a) and MPO in both groups and serum MPO-anti-antineutrophilic cytoplasmic antibody(ANCA) in MPO-AAV group were measured by enzyme linked immunosorbent assay (ELISA), while the disease activity was evaluated by Birmingham vasculitis activity score-V3 (BVAS-V3).Results:Compared with the heathy control group, the expression of MPO mRNA in neutrophils, serum MPO and complement C5a in MPO-AAV group were significantly higher[MPO mRNA:30.2±11.5 vs. 1.9±0.6, P<0.001;MPO:(112.0±68.7) IU/L vs. (87.4±22.9) IU/L, P=0.01; C5a:(187.3±90.3) ng/ml vs. (107.3±31.1) ng/ml, P<0.001; respectively], while the mean fluorescence intensity (MFI) of MPO in neutrophils were significantly lower [ 1 343.3±723.4 vs. 2 868.0±1 136.5, P<0.001]. In MPO-AAV group, the expression of neutrophil MPO mRNA was positively correlated with serum MPO-ANCA and MPO levels ( r=0.537, P=0.001 and r=0.358, P=0.032; respectively). Multiple regression analysis suggested that neutrophil MPO mRNA expression was positively correlated with serum MPO-ANCA level ( β=0.695, P=0.006); neutrophil MPO level was negatively correlated with serum MPO-ANCA, MPO and complement C5a levels ( r=-0.335, P=0.046; r=-0.372, P=0.026; r=-0.577, P<0.001; respectively). Further, neutrophil MPO level was negatively correlated with serum complement C5a level ( β=-0.374, P=0.043). BVAS-V3 was positively correlated with MPO mRNA expression in neutrophils, serum MPO-ANCA, MPO and complement C5a ( r=0.598, P<0.001; r=0.599, P<0.001; r=0.537, P=0.001; r=0.415, P=0.012; respectively) and negatively correlated with MPO level in neutrophils ( r=-0.342, P=0.041). In multiple regression analysis it suggested that BVAS-V3 was positively correlated with MPO mRNA expression in neutrophils ( β=0.511, P=0.002). Conclusion:In MPO-AAV patients, MPO synthesis and release in neutrophils are both significantly increased, which might be influenced by serum MPO-ANCA and C5a, respectively. Furthermore, MPO synthesis activity in neutrophils is an independent factor related to disease activity.

Role of C3a and C5a in focal segmental glomerulosclerosis / 中华肾脏病杂志

Objective To study the role of C3a and C5a in focal segmental glomerulosclerosis (FSGS) patients. Methods (1) A total of 66 patients with FSGS confirmed by renal biopsy were selected, including 18 cases of tip lesion, 11 cases of perihilar, 22 cases of not otherwise specified (NOS), 10 cases of cellular, and 5 cases of collapsing FSGS. The normal renal tissue resected from patients with kidney tumor was taken as a negative control. The expression of C3a and C5a in renal tissues was detected by immunohistochemistry. (2) Serum and urine samples from these 66 FSGS patients were collected, and serum and urine samples from 10 healthy adult selected from the same physical examination center in the same term were used as normal controls. The levels of C3a and C5a in serum and urine were detected by enzyme - linked immunosorbent assay (ELISA). Results (1) Immunohistochemical results showed that C3a and C5a were deposited in glomerulus of FSGS patients, and no deposition in normal renal tissues. The semi - quantitative score showed that kidney C3a score was significantly correlated with serum creatinine (r=0.547, P＜0.001) and 24 h urine protein (r=0.329, P=0.007) in FSGS patients, and kidney C5a score was also significantly correlated with serum creatinine (r=0.415, P＜0.001) and 24 h urine protein (r=0.414, P＜0.001) in FSGS patients. (2) The levels of serum C3a and C5a in FSGS patients were higher than those in healthy adults (both P＜0.05), but there was no significant difference among the five pathological types (P＞0.05). The levels of urinary C3a/urinary creatinine, urinary C5a/urinary creatinine were higher in FSGS patients than those in healthy adults (all P＜0.05). The levels of urine C3a/urinary creatinine and urinary C5a/urinary creatinine in collapsing FSGS were higher than other FSGS types (all P＜0.01), but there was no significant difference among the tip lesion, the perihilar, the not otherwise specified and the cellular (P＞0.05). (3) Urinary C3a/urinary creatinine levels were significantly correlated with serum creatinine (r=0.774, P＜0.001) and 24 h urine protein (r=0.430, P＜0.001) in FSGS patients, and urinary C5a/urinary creatinine levels were also significantly correlated with serum creatinine (r=0.677, P＜0.001) and 24 h urine protein (r=0.333, P=0.007) in FSGS patients. Conclusion Complement C3a and C5a may be involved in the pathogenesis of FSGS and may be related to the severity of FSGS.

Complement C3a, But Not C5a, Levels in Amniotic Fluid Are Associated with Intra-amniotic Infection and/or Inflammation and Preterm Delivery in Women with Cervical Insufficiency or an Asymptomatic Short Cervix (≤ 25 mm)

BACKGROUND: We aimed to estimate whether elevated levels of complement C3a and C5a in amniotic fluid (AF) are independently associated with increased risks of intra-amniotic infection and/or inflammation (IAI) and spontaneous preterm delivery (SPTD) in women with cervical insufficiency or a short cervix (≤ 25 mm). METHODS: We conducted a retrospective cohort study of 96 consecutive women with cervical insufficiency (n = 62) or a short cervix (n = 34) at 17 to 27 weeks, and who underwent an amniocentesis. AF was cultured and analyzed for C3a and C5a by enzyme-linked immunosorbent assay kits. The primary outcome measures were IAI (defined as a positive AF culture and/or an elevated AF interleukin-6 level [≥ 7.6 ng/mL]) and SPTD at < 32 weeks. RESULTS: In multivariable analysis, AF level of C3a was the only variable significantly associated with IAI, whereas C5a level in AF and serum C-reactive protein level were not associated with IAI. Using SPTD at < 32 weeks as the outcome variable in logistic regression, elevated AF levels of C3a were associated with increased risk of SPTD at < 32 weeks after adjusting for other baseline confounders, whereas elevated AF levels of C5a were not. CONCLUSION: In women with cervical insufficiency or a short cervix, elevated AF level of C3a, but not C5a, is independently associated with increased risks of IAI and SPTD at < 32 weeks. These findings suggest that subclinical IAI or SPTD in the context of cervical insufficiency is related to activation of complement system in AF.

Complement in ANCA-associated vasculitis / 中华检验医学杂志

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of autoimmune diseases with rapid progession and poor prognosis.The histopathological hallmark in the kidneys of patients with AAV is " pauci-immune" necrotizing crescentic glomerulonephritis,therefore complement was previously suggested not to play a major role in the disease development.However,in the recent years,accumulating evidence from both experimental and clinic study has strongly incriminated alternative complement pathway activation as critically important in the pathogenesis of AAV.In patients with AAV,plasma levels of Bb and FH,components of the alternative complement pathway,are associated with disease activity and prognosis,which might be useful biomarkers in monitoring systemic disease activity and renal disease activity in AAV.The complement activation product C5a and its interaction with C5a receptor play a central role.It is suggested that neutrophils,ANCA and complement system form a positive feedback loop contributing to the development of AAV.Preliminary data of two clinical trials have demonstrated effectiveness and safety of C5a receptor blockade in patients with AAV.Therefore,measurement of complement biomarkers will be helpful in assessing the disease activity of patients and be of great importance for monitoring the efficiency of complement-targeting therapy in the future.

Mechanisms and role of complement C5a in paraquat -induced acute lung injury / 中国药理学与毒理学杂志

The lung is a major damage tissue in paraquat(PQ)-caused acute poisoned patients. Most deaths from acute PQ poisoning can be attributed to acute lung injury(ALI). Complement activa?tion product C5a causes inflammatory cells,such as neutrophils and macrophages,to accumulate into the lung and get activated. These activated inflammatory factors generate a large number of oxidants and inflammatory sequelae named cytokine storm to mediate ALI induced by PQ poison. The review focused on the role and mechanisms of complement C5a in PQ-induced ALI.

Effect of Complement C5a/C5aR pathway on autophagy induced by renal ischemia-reperfusion injury / 中华器官移植杂志

Objective To investigate the expression of autophagy and the effect of complement C5a/C5aR pathway on autophagy induced by renal ischemia reperfusion injury (IRI).Methods MaleWT and C5aR gene knockout (BALB/C background) mice were selected.The model of renal IRI was established by occluding bilateral renal pedicles with microaneurysm clamps.Mice were divided into wild type BALB/C (WT) group and C5aR gene knock out (C5aRKO) group.The pathology of kidney was assessed by HE staining.The levels of BUN and KIM-1 were detected 24 h after reperfusion.The expression of the autophagy-associated protein (LC3 Ⅱ/LC3 Ⅰ and P62) was measured by Western blotting and immunofluorescence.In vitro,human renal tubular epithelial cells (HK2) were cultured.The expression of LC3 in HK2 cells was investigated by immunofluorescence and Western blotting after being treated with recombinant C5a or C5a combined with C5aR antagonist (C5aRA).Results As compared with WT group,the severity of kidney injury was obviously reduced in C5aRKO group (P＜0.05).After ischemia-reperfusion,the expression of autophagy-related protein LC3 gradually increased with the reperfusion time prolonged.The level of autophagy induced by ischemia-reperfusion was significantly reduced in C5aRKO group as compared with WT group (P＜0.05).In addition,the expression of autophagy-related protein LC3 Ⅱ in HK2 cells was increased with the augment of C5a stimulation concentration in vitro.Blockage of C5aR pathway by C5aRA led to a significant decrease in autophagy (P ＜ 0.05).Conclusion Complement C5a/C5aR pathway promotes renal IRI-induced autophagy.

Changes in serum levels of Th22 cell-related cytokines and complements in patients with drug eruption before and after treatment / 中华皮肤科杂志

Objective To investigate changes in serum levels of Th22 cell ? related cytokines and complements in patients with drug eruption before and after treatment, and to explore their possible roles in the occurrence and development of drug eruption. Methods This study included 35 patients with drug eruption, and 35 sex?and age?matched healthy controls. Five milliliters of peripheral blood samples were collected from the controls and patients before and after treatment. Enzyme?linked immunosorbent assay(ELISA)was performed to measure serum levels of interleukin 22(IL?22)and IL?13, and the cytometric bead array(CBA)system was used to determine serum levels of tumor necrosis factor?α(TNF?α) and complement components C3a, C4a and C5a. Results Before treatment, the patients with drug eruption showed significantly higher serum levels of IL?22(40.85 ± 14.56 vs. 29.09 ± 8.66 ng/L, t=5.549, P 0.05). Correlation analysis showed positive correlations between complement C3a and C4a serum levels(r = 0.660, P < 0.05), between C3a and C5a serum levels(r = 0.404, P < 0.05), between C4a and C5a serum levels(r = 0.501, P < 0.05), and between IL ? 22 and TNF ? α serum levels(r = 0.573, P = 0.005), but negative correlations between IL ? 22 and complement C3a serum levels(r = -0.490, P = 0.005), in patients before treatment. Conclusion The activation of Th22 cell?related cytokines and complements may play important roles in the occurrence and development of drug eruption, and IL?22 may participate in the regulation of complements.

Homeostasis of complement system and the severity of coronary artery disease / 中华检验医学杂志

Objective To investigate if the relative ratio between C1q and C3a, C5a had a relationship with the extent of coronary artery disease ( CAD) which had never been evaluated in humans.Methods Fifty-three patients scheduled for elective percutaneous coronary intervention ( PCI ) from February, 2016 to April, 2016 at Fuwai hospital were prospectively enrolled.According to the clinical and angiographic characters patients were divided into two groups:acute coronary syndrome ( ACS) group ( n=24), and control group (n=29, 19 patients with stable angina and 10 patients without CAD confirmed by angiography).In all individuals, fasting venous blood was collected by EDTA tubes after admission and strictly before PCI.The plasma level of C1q was measured by immune turbidimetric analysis, C3a and C5a were measured by ELISA tests.Differences between groups were assessed using t test, Mann-Whitney Utests, chi-squared test or Fisher exact test depending on the type of data respectively.Multivariate logistic regression analyses were conducted to evaluate the adjusted effect of C1q, C3a, C5a, C1q/C3a and C1q/C5a on ACS.Results Compared with control group, ACS group has an elevated circulation level of C3a (4 531.14 μg/L vs.4 179.95 μg/L, t=1.381,P=0.173) and C5a (6.44 μg/L vs.4.42 μg/L, t=0.133, P=0.108) but a decreased level of C1q (176.98 μg/ml vs.200.60 μg/ml, t=-2.022, P=0.048).The relative ratio of C1q/C3a was significantly decreased in ACS patients(4.05 ×10 -2 vs.4.97 × 10 -2 , t=-2.484, P=0.016).According to the multiple logistic regression analysis, lower relative ratio of C1q/C3a level proved to be independently associated with ACS ( OR=0.937, P=0.047, 95% CI:0.879-0.998).Conclusions The decreased relative ratio of C1q/C3a level proved to be independently associated with ACS.C1q/C3a ratio could be used as an important index reflecting the complement system homeostasis status which might have potential clinical value in evaluating the prognosis of patients with CAD.

Correlation between serum levels of complement C5a and liver fibrosis markers in patients with obstructive jaundice / 临床肝胆病杂志

ObjectiveTo investigate the change in the serum level of complement C5a after obstruction removal and its correlation with the serum levels of liver fibrosis markers in patients with obstructive jaundice. MethodsA total of 164 patients with obstructive jaundice who underwent endoscopic retrograde cholangiopancreatography and obstruction removal in our hospital from June 2012 to June 2014 were enrolled, and 20 healthy adults were enrolled as the control group. The serum levels of complement C5a and four liver fibrosis markers, type Ⅳ collagen (ⅣP), pre-type Ⅲ collagen (PⅢP), laminin (LN), and hyaluronic acid (HA), were measured. The t-test was applied for comparison between groups, and linear correlation analysis was applied for correlation analysis. ResultsCompared with the healthy controls, the patients with obstructive jaundice had a significantly higher serum level of complement C5a (89.7±30.2 vs 62.2±21.1 ng/L; t=2.213, P=0.016), and the serum level of complement C5a was closely related to the course of obstruction (r=0.954, P=0003). The serum level of complement C5a decreased significantly after obstruction removal (66.2±26.3 ng/L; t=1.998, P=0.021). Before obstruction removal, the serum level of complement C5a increased synchronously with those of ⅣP (r=0.976, P＜0.001), PⅢP (r=0972, P＜0.001), LN (r=0.915, P=0.039), and HA (r=0.962, P=0.002); after obstruction removal, the serum level of complement C5a decreased synchronously with those of ⅣP (r=0.965, P=0.001), PⅢP (r=0.912, P=0.003), and HA (r=0.875, P=0023). ConclusionComplement C5a may be involved in the development of liver fibrosis induced by obstructive jaundice.

Deficiency of C3a/C5a receptors protect kidney from injury in IgA nephropathy / 中国免疫学杂志

Objective:To investigate the role of C3a,C5a and their receptors in the pathogenesis of IgA nephropathy (IgAN). Methods:A total of twenty-eight 6-8 weeks old female BALB/c mice were investigated.And they were negative control group , WT group,C3aR-/-group,C5aR-/-group(the latter three groups were named as experimental groups ),seven mice in each group.All the mice were infected through respiratory tract with infectious SV (experimental groups) or PBS(negative control group),combined with tail vein challenge to make IgAN animal model.Testing 24 h total urinary protein , serum urea nitrogen ( BUN ) and creatinine ( Cr ) , using direct immunofluorescence to test the renal deposition of IgA and C 3,observing renal pathologic lesion under PAS staining with light microscopy.RT-qPCR was used to test the relative mRNA expression of TNF-α,TGF-β,IL-1β,IL-6,MCP-1.Results: After 15 weeks,the level of UTP in experimental group was significantly higher than negative control group ,and the same results as WT group than C3aR-/-group and C5aR-/-group.There was no significant difference among groups for BUN and Cr.Combined with negative control group , experimental groups had significant renal pathological lesions , and the changes of WT group was more severe than C3aR-/-group and C5aR-/-group.The results of relative mRNA expression of TNF-α,TGF-β,IL-1β,IL-6,MCP-1 was the same as the level of 24 h UTP,at the same time,the relative mRNA expression of IL-1β,IL-6,MCP-1 in C3aR-/-group was significantly less than C5aR-/-group.Conclusion:The deficiency of C3a/C5a receptors can protect kidney from injury in IgAN ,and C3a receptor has more significant role in protect kidney from injury in IgAN.

Advances in research on relationships between complement 5a and acute lung injury / 军事医学

Acute lung injury ( ALI) is a type of pulmonary excessive inflammation with high morbidity and mortality.It can be induced by multiple causes.There are currently no successful therapeutic or preventive measures because the patho-genesis of ALI has not been completely clarified.Many studies have shown that the activation of complement 5a (C5a) and its receptors is necessary in the process of ALI.Drug development targeting on C5a and its receptors may bring new hope to the treatment of ALI.In this article, the experimental evidence and possible mechanisms are summarized to reveal the rela-tionship between C5a and ALI.

Investigation on the serum marker of MPO-ANCA associated vasculitis in active phase / 医学研究生学报

Objective Antineutrophil cytoplasmic antibody (ANCA) associated vasculitis(AAV)is a systemic necrotizing small-vessel vasculitis, and myeloperoxidase(MPO) is one of the main antigens that ANCA can recognize.This study was to investigate the clinical significance of MPO, activated complement C5a fragment and ceruloplasmin ( Cp) in the peripheral blood of patients with MPO-ANCA associated vasculitis ( MPO-AAV) in active phase by observing their changes. Methods 132 MPO-AAV patients at active stage were selected as the patient group, while the control group was made up of 30 healthy controls.Peri-nuclear ANCA (p-ANCA) and MPO-ANCA in the patient group were detected by IIF and ELISA, respectively.The levels of MPO, Cp and C5a in both groups were tested by ELISA.The Birmingham vasculitis activity score (BVAS) of every patient was calculated.In the patient group, the relationship among MPO, Cp, C5a and MPO-ANCA were analysed, and the association between BVAS and each of them was also explored. Results The levels of MPO, CP, C5a in the patient group were significantly higher than those in the health control group [MPO:400.7(333.5~506.1) vs 286.9(225.5~329.1)IU/L, P<0.001;C5a:336.7 (277.6~403.5) vs 236.8 (204.2~304.1) ng/mL, P<0.001;Cp:481.1 (387.9~535.9) vs 326.9 (177.1~405.5) ng/mL,P<0.001].The associations between MPO and Cp, C5a and MPO, C5a and Cp in the patient group were statistically significant ( r=0.663, P<0.001;r=0.792, P<0.001;r=0.637, P<0.001, respectively).No significant correlation was found in MPO-ANCA and any of these indexes.MPO-ANCA had a positive association with the total BVAS, the kidney BVAS, and the lung BVAS ( r=0.247, P=0.004;r=0.339,P<0.001 and r=0.191, P=0.028, respec-tively) .p-ANCA had a positive correlation with the kidney BVAS ( r=0.208, P=0.017) while C5a had a negative correlation with the kidney BVAS ( r=-0.207, P=0.018) . Conclusion The levels of MPO, Cp and C5a increased significantly in the peripheral blood of MPO-AAV patients in active phase.The complex interactions among MPO, Cp, C5a and ANCA might influence the clinical damage in MPO-AAV.Notablely, the influence from MPO-ANCA might be most obvious while C5a might affect renal damage more markedly.

Regulation effect of complement C5a on interleukin-17 during renal allograft rejection / 重庆医学

Objective To investigate the expression of proinflammatory cytokine interleukin-17(IL-17) and complement cleavage fragment C5a and the regulation effect of C5a on the expression of IL-17 during renal allograft rejection .Methods The frequency of IL-17+ T cell in peripheral blood and the expression of IL-17 in renal tubular epithelial cells (HK2) after C5a stimulation in renal transplant recipients were measured by flow cytometry and the changes of serum C5a level was detected by ELISA ,respectively .Im-munohistochemistry was applied to detect and compare the expression of IL-17 and the deposition of C5b-9 in normal renal tissues and renal tissues with allograft rejection .The difference of IL-17 expression in HK2 cells before and after the recombinant C5a stimulation was detected by immunocytochemistry .Results Both the percentage of IL-17+ T cells and serum C5a levels were sig-nificantly increased after the allogeneic renal transplantation .Compared with normal renal tissues ,both the deposition of C5b-9 and the IL-17 expression in renal tissues with allograft rejection was remarkably up-regulated ,which showed the positive correlation be-tween them .The expression of IL-17 in HK2 was obviously up-regulated by the recombinant C5a stimulation .Conclusion C5a may positively regulate the expression of IL-17 by tubular epithelial cells during the renal allograft rejection .

Expression of C3a, C5a, TXA2, LT in pulmonary injury of infant open heart surgery improved with the modified ultrafiltration technique / 中国医师杂志

Objective To study the mechanism of pulmonary injury and protective effect of modified ultrafiltration on lung function in infant open heart surgery.Methods According to the wishes of parents,40 cases of congenital heart disease were divided into without modified ultrafiltration control group (C) and modified ultrafiltration group (M),and parents signed informed consent.The cardiopulmonary bypass (CPB) was used without ultrafiltration in Group C,while with modified ultrafiltration in group M.The pneumodynamic parameters and C3a,C5a,TXA2,LT were measured at specific time points.Results The static pulmonary compliance (Cstat) and oxygen index (OI) were lower,and alveolar-arteria oxygen difference (AaDO2) was higher after CPB in the two groups(P ＜ 0.05).At T3,T4 and T5 time points,the Cstat and OI in Group M was higher than that in Group C; AaDO2 in Group M was lower than that in Group C (P ＜0.05).The levels of C3a and C5a were lower after CPB in the two groups; levels of TXA2,LT were higher after CPB in the C groups.At T2,T3,T4 and T5 time points,the TXA2 and LT in Group M were lower than that in Group C(P ＜0.05).Conclusions The pulmonary injury in pediatric open heart surgery may be concerned with the the alexin(C3a,C5a) activation and I/R.The level of C3a and C5a was considered earlier index of inflammatory reaction and pulmonary injury.Modified ultrafiltration improves pulmonary function due to elevating coloid osmotic pressure and degrading the plasma level of TXA2,LT.

The role of C5aR and P38-MAPK in the rats model of septic shock with myocardial injury / 中华急诊医学杂志

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.

Establishment of screening platform in vitro for C5a receptor antagonists / 国际药学研究杂志

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.

Complement C5a, C5a receptor and their antagonists: Research advances / 国际药学研究杂志

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.

Calpain-mediated Cleavage of Atg5 Determine Autophagy or Apoptosis of PMN, and C5a's Role / 生物化学与生物物理进展

Apoptosis of neutrophils controls the duration and the intensity of an inflammatory response and therefore the extent of neutrophil- mediated tissue damage, disturbance of neutrophil apoptosis has been associated with many diseases, underlying mechanism is not elucidated. C5a is a complement fragment that has multifunctional properties, which induces neutrophil chemoattraction, an oxidative burst, enhancement of phagocytosis, release of granule enzymes, and suppress neutrophil apoptosis. Several studies have reported calpain is involved in both neutrophil functions and apoptosis and it might play a more specific role in the regulation of neutrophil apoptosis. Diffenrent isoform of calpains is activted by diffenrent stimuli through different transduction pathway. It was reported previously that calpain is required for neutrophil migration and chemotaxis induced by C5a. In addition, autophagy is a ubiquitous physiological process that occurs in all eukaryotic cells and is considered to be a survival mechanism. Atg5 promotes autophagy and is indispensable to autophagosome formation. Upon calpain activation, Atg5 is cleaved and the resulting 24 ku Atg5 mediates apoptosis while losting the property of autophagy. Therefore, Atg5 represents a molecular switch between autophagy and apoptosis. The interaction among the C5a, calpain and Atg5 was introduced and new direction for further research was provided.