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.

Changes in serum C3d and C5b-9 levels in elderly patients with idiopathic membranous nephropathy and their clinical significance / 中华老年医学杂志

Objective:To investigate changes in serum C3d and C5b-9 levels in elderly patients with idiopathic membranous nephropathy(IMN)and their correlations with prognosis.Methods:Two hundred thirty-one elderly patients with IMN and 96 non-elderly patients with IMN confirmed by kidney biopsy at the First Affiliated Hospital of Zhengzhou University from January 2015 to May 2017 were enrolled.During the same period, 118 healthy individuals receiving health checkups were included as controls.Patients were divided into the low C3d group( n=112)and the high C3d group( n=113)according to the median level of serum C3d.Serum C3d and C5b-9 levels were measured by enzyme-linked immunosorbent assays. Results:Serum C3d and C5b-9 levels in elderly IMN patients were 0.23(0.15, 0.45)mg/L and 0.28(0.20, 1.23)mg/L, respectively, which were higher than those in healthy controls[0.18(0.13, 0.22)mg/L, 0.22(0.16, 0.26)mg/L, respectively]( Z=-4.261 and -6.213, P<0.001). Serum C3d levels in elderly and non-elderly IMN patients were correlated negatively with the estimated glomerular filtration rate( r=-0.155 and -0.426, P=0.019 and 0.000), but positively with serum creatinine, anti-phospholipase A2 receptor(PLA2R)antibody levels and 24 h urinary protein( r=0.184, 0.326, 0.407, 0.321 and 0.145, P=0.005, 0.001, 0.000, 0.001 and 0.027). Kaplan-Meier survival analysis showed that the cumulative renal survival rate in elderly IMN patients was lower in the high C3d group than in the low C3d group(47.8% vs.70.8%, Log Rank χ2=7.399, P=0.007). Multivariate Cox regression analysis showed that high C3d levels were an independent risk factor for poor renal outcomes in elderly IMN patients( HR=2.288, 95% CI: 1.082-4.839, P=0.030). Conclusions:High serum C3d levels are associated with increases in urinary protein excretion and anti-PLA2R antibody levels, renal function decline, and poor renal outcomes in elderly IMN patients.

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.

The role of complement signaling pathway in the pathogenesis of neuromyelitis optica / 中华眼底病杂志

Neuromyelitis optica (NMO) is a kind of demyelinating disorder that preferentially affects the optic nerves and spinal cord and results in permanent vision loss.NMO pathogenesis is thought to involve binding of anti-aquaporin-4 (AQP4) auto-antibodies to astrocytes,which causes complement-dependent cytotoxicity (CDC) and downstream inflammation leading to oligodendrocyte and neuronal injury.Vasculocentric deposition of activated complement is a prominent feature of NMO pathology.In recent years,a number of groups have found complements play an important role in the pathogenesis of NMO,and basic researches in NMO therapy due to its specificity and uniformity.Its inhibition would protect against proteins in the classical complement pathway so that cure the disease.This review will expound the the role of complement signaling pathway in the pathogenesis of NMO,and provide reference for a more in-depth understanding and clinical treatments of NMO.

Efficacy of eculizumab in paroxysmal nocturnal hemoglobinuria patients with or without aplastic anemia: prospective study of a Korean PNH cohort

BACKGROUND: Patients with paroxysmal nocturnal hemoglobinuria (PNH) often have concurrent aplastic anemia (AA). This study aimed to determine whether eculizumab-treated patients show clinical benefit regardless of concurrent AA. METHODS: We analyzed 46 PNH patients ≥18 years of age who were diagnosed by flow cytometry and treated with eculizumab for more than 6 months in the prospective Korean PNH registry. Patients were categorized into two groups: PNH patients with concurrent AA (PNH/AA, N=27) and without AA (classic PNH, N=19). Biochemical indicators of intravascular hemolysis, hematological laboratory values, transfusion requirement, and PNH-associated complications were assessed at baseline and every 6 months after initiation of eculizumab treatment. RESULTS: The median patient age was 46 years and median duration of eculizumab treatment was 34 months. Treatment with eculizumab induced rapid inhibition of hemolysis. At 6-month follow-up, LDH decreased to near normal levels in all patients; this effect was maintained until the 36-month follow-up regardless of concurrent AA. Transfusion independence was achieved by 53.3% of patients within the first 6 months of treatment and by 90.9% after 36 months of treatment. The mean number of RBC units transfused was significantly reduced, from 8.5 units during the 6 months prior to initiation of eculizumab to 1.6 units in the first 6 months of treatment, for the total study population; this effect was similar in both PNH/AA and classic PNH. CONCLUSION: This study demonstrated that eculizumab is beneficial in the management of patients with PNH/AA, similar to classic PNH.

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.

Association of CYP3A5 and C5 polymorphisms with the individual dosage regimen of tacrolimus in Chinese liver transplantation recipients during the early post-transplantation period / 中华器官移植杂志

Objective To investigate the effect of CYP3A5 and C5 gene polymorphisms on the concentration/dose ratio of tacrolimus in Chinese liver transplant patients during the early posttransplantation period.Methods A total of 100 adult patients who underwent primary liver transplantation (LT) were enrolled.Tacrolimus dosage and trough blood concentration were detemined at first week after liver transplantation.Two single-nucleotide polymorphisms were genotyped and analyzed in both donor and recipient groups.The relationship between gene polymorphisms and tacrolimus concentration/dose ratio (C/ D ratio) was analyzed.Results The distribution of allele A in C5 rs17611 was 63.5 ％ among donors and 58.5％ among recipients.For CYP3A5,the rs776746 allele G represented the major alleles in both donors and recipients (71％ and 72％,respectively).The tacrolimus C/D ratio of recipients carrying allele AA in C5 rs17611 was significantly higher than that of recipients carrying the C5 rs17611 allele G.Both donor and recipient CYP3A5 rs776746 polymorphisms were highly correlated with the tacrolimus C/D ratio at first week after liver transplantation.No linkage disequilibrium between CYP3A5 rs776746 and C5 rs17611 polymorphisms was found (D'max =0.392,r2max =0.034).Recipient CYP3A5 rs776746 allele A,C5 rs17611 genotype AA,and donor CYP3A5 rs776746 allele A were associated with rapid tacrolimus metabolism.With increasing number of these alldes,tacrolimus C/D ratio was reduced during the one week after transplantation.Conclusion Recipient C5 rs17611 polymorphism is a new genetic locus that influences tacrolimus metabolism in patients after OLT during the early post-transplantation periocd.

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.

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.

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.

The genetic predisposition of complement C5 gene polymorphisms in proliferative diabetic retinopathy in Chongqing Han population / 中华眼底病杂志

Objective To observe the genetic predisposition of complement C5 gene polymorphisms in proliferative diabetic retinopathy (PDR) in Chongqing Han population.Methods 400 type 2 diabetes (T2D) patients (case group) and 600 age-and sex-matched healthy controls (control group) were enrolled in this study.There were 8 PDR patients in case group.All the subjects were Han ethnic people.The immune-related representative SNP locus of C5 gene including rs2269067,rs7040033,rs7027797 were screened by linkage disequilibrium analysis.Locus rs1017119 was selected by TagSNP and was around the above three loci.Subjects' peripheral venous blood was collected and DNA was extracted.Genotyping was examined by PCR-restriction fragment length polymorphism method.The level of C5 plasma protein was measured by enzyme-linked immunoabsorbent assay.Results The frequency of GG genotype of rs2269067 was significantly increased in PDR patients in cases group compared with controls (Pc=3.4 × 10-5,OR=1.87,95％CI=1.43-2.44;P=3.1 × 10-6).There was no differences in frequency of G,CC and CG genotype of rs2269067 between two groups (P=1.4 × 10-4,1.000,1.0 × 10-6).There were no differences in frequency of G,CC,CG,GG genotype of rs7040033,rs1017119,and rs7027797 between two groups (P＞0.05).The production of C5 plasma protein was significantly increased in case group as compare with control group (P=0.0004).An increased production of C5 plasma protein was observed in rs2269067 GG genotype cases compared to CG or CC cases (P=0.003,0.001).Conclusion C5 rs2269067 GG genotype may be associated with the PDR of T2D in Chongqing Han population.

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.

Case for diagnosis

Degos disease, also known as malignant atrophic papulosis, is a rare occlusive vasculopathy of unknown etiology characterized by infarcts in the dermis, gastrointestinal tract, central nervous system, and other organs. It is characterized by papules, which become umbilicated and evolve with a depressed porcelain-white central area, with an erythematous halo with telangiectasias. Histological findings include wedge-shaped dermoepidermal necrosis and blood vessel thrombosis. Approximately 50-60% of patients with systemic symptoms die within 2-3 years, most due to gastrointestinal perforation. We report a typical case, with lethal outcome, in a 45-year-old woman.

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.

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.

Do Archaea and bacteria co-infection have a role in the pathogenesis of chronic chagasic cardiopathy?

Chronic cardiopathy (CC) in Chagas disease is a fibrotic myocarditis with C5b-9 complement deposition. Mycoplasma and Chlamydia may interfere with the complement response. Proteolytic enzymes and archaeal genes that have been described in Trypanosoma cruzi may increase its virulence. Here we tested the hypothesis that different ratios of Mycoplasma, Chlamydia and archaeal organisms, which are frequent symbionts, may be associated with chagasic clinical forms. MATERIALS AND METHODS: eight indeterminate form (IF) and 20 CC chagasic endomyocardial biopsies were submitted to in situ hybridization, electron and immunoelectron microscopy and PCR techniques for detection of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae(CP), C5b-9 and archaeal-like bodies. RESULTS: MP and CP-DNA were always present at lower levels in CC than in IF (p < 0.001) and were correlated with each other only in CC. Electron microscopy revealed Mycoplasma, Chlamydia and two types of archaeal-like bodies. One had electron dense lipid content (EDL) and was mainly present in IF. The other had electron lucent content (ELC) and was mainly present in CC. In this group, ELC correlated negatively with the other microbes and EDL and positively with C5b-9. The CC group was positive for Archaea and T. cruzi DNA. In conclusion, different amounts of Mycoplasma, Chlamydia and archaeal organisms may be implicated in complement activation and may have a role in Chagas disease outcome.

Expression of Complement C3a Receptor and C5a Receptor by A(beta)(1-42) Stimulated Human Neuroblastoma Cell Line

BACKGROUND: Complementary receptors have been suggested to play causative roles in the neuroinflammatory process of Alzheimer's disease (AD). The genetic expressions of the C3a receptor (C3aR), C5a receptor (C5aR) and the protein expressions of the C3aR and C5aR were examined in the human neuroblastoma cell line, SK-N-SH, after the administration of amyloid peptide (A1-42). METHODS: SK-N-SH cells were incubated overnight with a single dose of 20 M of aggregated A (A1-42). An inhibition study was done with actinomycin D (ActD, 2.5 M) or with the administration of cycloheximide (CHX, 2.5 M) to the cell suspension. Messenger RNA expressions of C3aR and C5aR were detected by RT-PCR. The intensity of bands from 6% polyacrylamide electrophoretic gel was analyzed by a bioimage analyzer. The protein production of C3aR and C5aR in the A-treated cells was also measured by flow cytometry. NFB activation after treatment of A in the cells was detected by an electrophoretic mobility-shift assay. RESULTS: A1-42 increased the expression of C3aR and C5aR. ActD inhibited the expression of both anaphylatoxin receptors but CHX only suppressed C5aR mRNA expression. Activated NFB was demonstrated in the A-stimulated cells. CONCLUSIONS: C3aR and C5aR were constitutively expressed in the human neuroblastoma SK-N-SH cell. Expression of these anaphylatoxin receptors was upregulated after A1-42 stimulation, which as a result, may contribute to the complement-mediated neuroinflammation of AD.

Depression of Ca2+ influx in complement C5a-stimulated neutrophils by calmodulin inhibitors

Role of Ca2+/calmodulin complex in intracellular Ca2+ mobilization in neutrophils has not been clearly elucidated. In this study, effects of chlorpromazine, trifluoperazine and imipramine on the intracellular Ca2+ mobilization, including Ca2+ influx, in C5a-activated neutrophils were investigated. Complement C5a-stimulated superoxide production and myeloperoxidase release in neutrophils were inhibited by chlorpromazine, trifluoperazine and imipramine, except no effect of imipramine on myeloperoxidase release. A C5a-elicited elevation of (Ca2+)i in neutrophils was inhibited by chlorpromazine, trifluoperazine, imipramine, staurosporine, genistein, EGTA, and verapamil but not affected by pertussin toxin. The intracellular Ca2+ release in C5a-activated neutrophils was not affected by chlorpromazine and imipramine. Chlorpromazine and imipramine inhibited Mn2+ influx by C5a-activated neutrophils. Thapsigargin-evoked Ca2+ entry was inhibited by chlorpromazine, trifluoperazine, imipramine, genistein, EGTA and verapamil, while in the activation process of neutrophils. The depressive action of calmodulin inhibitors on the elevation of cytosolic Ca2+ level in C5a-activated neutrophils appears to be accomplished by inhibition of Ca2+ influx from the extracellular medium.

A comparative study on urinary complement C5b-9 complex excretion in four nephritis models of rats / 中国病理生理杂志

AIM: To explore the significance of measuring urinary complement C5b-9 complex in various types of immune complex (IC) nephritis models of rats. METHODS: The four models of rats, namely, passive Heymann nephritis (PHN), anti-thymocyte serum nephritis(ATSN), anti-glomerular basement membrane nephritis (AGBMN) and chronic serum disease nephritis (CSDN) were reproduced. Then, the contents of complement C5b-9 complex in plasma and urine of the rats were detected with sandwich ELISA. And the deposits of C5b-9 complex in glomeruli of the rats were examined by ABC immunohistochemistry staining. RESULTS: The contents of rat plasma C5b-9 were elevated and deposits of C5b-9 in glomeruli could be detected in the four model rats. But the increased urinary excretion of C5b-9 was observed only in PHN rats. Moreover, the time of urinary C5b-9 complex excretion was earlier than that of urinary protein in the rats with PHN. CONCLUSION: Urinary C5b-9 complex excretion could be taken as one of several sensitive immunologic parameters in diagnosing of PHN and in distinguishing PHN from other type of nephritis.