The role of complement C5a receptor in DPSC odontoblastic differentiation and in vivo reparative dentin formation / 国际口腔科学杂志·英文版

Therapeutic dentin regeneration remains difficult to achieve, and a majority of the attention has been given to anabolic strategies to promote dentinogenesis directly, whereas, the available literature is insufficient to understand the role of inflammation and inflammatory complement system on dentinogenesis. The aim of this study is to determine the role of complement C5a receptor (C5aR) in regulating dental pulp stem cells (DPSCs) differentiation and in vivo dentin regeneration. Human DPSCs were subjected to odontogenic differentiation in osteogenic media treated with the C5aR agonist and C5aR antagonist. In vivo dentin formation was evaluated using the dentin injury/pulp-capping model of the C5a-deficient and wild-type mice. In vitro results demonstrate that C5aR inhibition caused a substantial reduction in odontogenic DPSCs differentiation markers such as DMP-1 and DSPP, while the C5aR activation increased these key odontogenic genes compared to control. A reparative dentin formation using the C5a-deficient mice shows that dentin regeneration is significantly reduced in the C5a-deficient mice. These data suggest a positive role of C5aR in the odontogenic DPSCs differentiation and tertiary/reparative dentin formation. This study addresses a novel regulatory pathway and a therapeutic approach for improving the efficiency of dentin regeneration in affected teeth.

Acute Pancreatitis with Purtscher's-like Retinopathy / 대한췌담도학회지

A 28-year-old man with a history of alcohol abuse was diagnosed with acute pancreatitis based on clinical symptoms, laboratory findings and computed tomography findings. On the second day of hospitalization, he complained of sudden visual disturbance. The ophthalmologic examination showed Purtscher's-like retinopathy. Two weeks after initial presentation, his vision was significantly improved along with epigastric pain. Retinal arteriolar occlusion by complement-mediated leukoembolization is the proposed pathogenic mechanism of Purtscher's-like retinopathy. Increased activity of proteases such as trypsin, associated with acute pancreatitis might be linked with the production of complement C5a. We report a rare case of Purtscher's-like retinopathy associated with acute pancreatitis.

Yersinia enterocolitica Exploits Signal Crosstalk between Complement 5a Receptor and Toll-like Receptor 1/2 and 4 to Avoid the Bacterial Clearance in M cells

In the intestinal mucosal surface, microfold cells (M cells) are the representative gateway for the uptake of luminal antigens. At the same time, M cells are the primary infection site for pathogens invading mucosal surface for their infection. Although it is well recognized that many mucosal pathogens exploit the M cells for their infection, the mechanism to infect M cells utilized by pathogens is not clearly understood yet. In this study, we found that M cells expressing complement 5a (C5a) receptor (C5aR) also express Toll-like receptor (TLR) 1/2 and TLR4. Infection of Yersinia enterocolitica, an M cell-invading pathogen, synergistically regulated cyclic adenosine monophosphate-dependent protein kinase A (cAMP-PKA) signaling which are involved in signal crosstalk between C5aR and TLRs. In addition, Y. enterocolitica infection into M cells was enhanced by C5a treatment and this enhancement was abrogated by C5a antagonist treatment. Finally, Y. enterocolitica infection into M cells was unsuccessful in C5aR knock-out mice. Collectively, we suggest that exploit the crosstalk between C5aR and TLR signaling is one of infection mechanisms utilized by mucosal pathogens to infect M cells.

Association between protective effect of Liuwei Wuling tablets against acute liver injury and its inhibitory effect on cytoplasmic translocation of high-mobility group box-1 in hepatocytes in mice / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the effect of Liuwei Wuling tablets on the cytoplasmic translocation and release of high-mobility group box-1 (HMGB1) in hepatocytes in mice with acute live injury induced by D-galactosamine (D-GalN) and lipopolysaccharide (LPS).</p><p><b>METHODS</b>A Balb/c mouse model of acute liver injury was established by intraperitoneal injection of D-GalN (400 mg/kg) and LPS (5 ug/kg). A total of 24 healthy mice were randomly and equally divided into acute liver injury control group and Liuwei Wuling tablet treatment group. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured in both groups at each time point within one week. Liver tissues were collected at 36 hours to perform pathological examination. The serum levels of HMGB1, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), complement 3a (C3a), and complement 5a (C5a) were measured. Immunohistochemistry was used to determine the expression and cytoplasmic translocation of HMGB1 in hepatocytes.</p><p><b>RESULTS</b>At 6, 12, and 24 hours, the Liuwei Wuling tablet treatment group had significantly lower serum levels of ALT than the control group (225.33±181.64 U/L vs 471.17±174.72 U/L, t = 3.38, P < 0.01; 1509.53±182.51 U/L vs 7149.52±734.25 U/L, t = 25.82, P < 0.01; 162.89±86.51 U/L vs 1318.16±557.71 U/L, t = 7.09, P < 0.01), as well as significantly lower serum levels of AST than the control group (179.22±94.57 U/L vs 561.91±209.6 U/L, t = 5.76, P < 0.01; 590.92±190.92 U/L vs 2266.48±705.64 U/L, t = 7.94, P < 0.01; 231.24±87.7 U/L vs 444.32±117.01 U/L, t = 5.05, P < 0.01). The treatment group had significantly lower levels of HMGB1 than the control group at 6 and 12 hours (54.21±11.89 ng/ml vs 72.07±13.65 ng/ml, t = 3.41, P < 0.01; 49.23±5.97 ng/ml vs 68.71±13.07 ng/ml, t = 4.70, P < 0.01). The treatment group had significantly lower levels of TNF-α, IL-1β, and IL-6 than the control group at 12 hours (163.62±9.12 pg/ml vs 237.09±51.47 pg/ml, t = 4.86, P < 0.01; 15.66±13.13 pg/ml vs 37.43±18.68 pg/ml, t = 3.30, P < 0.01; 7.10±3.06 pg/ml vs 21.42±8.23 pg/ml, t = 5.65, P < 0.01). The treatment group had significantly lower levels of C3a and C5a than the control group at 12 hours (2.52±1.27 pg/ml vs 9.83±2.96 ng/ml, t = 7.86, P < 0.01; 2.16±1.03 ng/ml vs 7.23±1.55 ng/ml, t = 9.67, P < 0.01). Compared with the control group, the treatment group had significantly reduced liver inflammation and necrosis, and a significantly lower cytoplasmic translocation rate of HMGB1 in hepatocytes (38.76%±7.37% vs 8.15%±2.11%, P < 0.01).</p><p><b>CONCLUSION</b>Liuwei Wuling tablets can reduce the cytoplasmic translocation of HMGB1 in hepatocytes and relieve liver inflammation in mice with acute liver injury.</p>

Levels of complement components C3a and C5a in renal injury among trichloroethylene-sensitized BALB/c mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To determine the levels of complement components C3a and C5a in the kidneys of trichloroethylene (TCE)-sensitized BALB/c mice, and to investigate the role of complement components in TCE-induced renal injury among BALB/c mice.</p><p><b>METHODS</b>Sixty-two female BALB/c mice were randomly divided into blank control group, vehicle control group, and TCE sensitization group. The mice in TCE sensitization group were sensitized by one intracutaneous injection and one abdominal smear of TCE. At 24 h, 48 h, 72 h, and 7 d after the second sensitization, mice were sacrificed, and the blood and kidneys were collected. An automatic biochemical analyzer was used in the determination of serum blood urea nitrogen (BUN) and creatinine (Cr). The levels of C3a and C5a in the kidneys were determined by immunohistochemistry.</p><p><b>RESULTS</b>The sensitization rate of TCE sensitization group was 42.0%. Kidney coefficient and serum levels of BUN and Cr were significantly increased in the TCE sensitization group as compared with the vehicle control group at 48 h and 72 h after sensitization (P < 0.05). The kidney coefficients of the TCE sensitization group at 48 h and 72 h were significantly higher than those of the control groups (P < 0.05). In comparison with the vehicle control group, however, no significant change was found in kidney coefficient, serum BUN, or serum Cr at 7 d after TCE sensitization (P > 0.05). Levels of C3a and C5a at 48 h (3.80±0.84 and 4.00±1.00, respectively) and 72 h (4.40 ± 1.14 and 4.40 ± 1.14, respectively) after sensitization were all significantly higher than those of the vehicle control group (P < 0.05), but no significant difference was found in level of C3a (1.80±0.45) or C5a (2.00 ± 0.71) at 7 d (P > 0.05).</p><p><b>CONCLUSION</b>TCE sensitization can induce renal injury in mice. Levels of complement components C3a and C5a are elevated in the kidneys of sensitized mice, indicating that C3a and C5a may be involved in the renal injury induced by TCE sensitization.</p>

Effect of anaphylatoxin C3a, C5a on the tubular epithelial-myofibroblast transdifferentiation in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Tubulointerstitial renal fibrosis is the common end point of progressive kidney diseases, and tubular epithelial-myofibroblast transdifferentiation (TEMT) plays a key role in the progress of tubulointerstitial renal fibrosis. Anaphylatoxin C3a and C5a are identified as novel profibrotic factors in renal disease and as potential new therapeutic targets. The aim of this study was to investigate whether C3a, C5a can regulate TEMT by transforming growth factor-β1 (TGF-β)/connective tissue growth factor (CTGF) signaling pathway and the effects of C3a and C5a receptor antagonists (C3aRA and C5aRA) on C3a- and C5a-induced TEMT.</p><p><b>METHODS</b>HK-2 cells were divided into C3a and C5a groups which were subdivided into four subgroups: control group, 10 ng/ml TGF-β1 group, 50 nmol/L C3a group, 50 nmol/L C3a plus 1 µmol/L C3aRA group; control group, 10 ng/ml TGF-β1 group, 50 nmol/L C5a group, 50 nmol/L C5a plus 2.5 µmol/L C5aRA group. TGF-β1 receptor antagonist (TGF-β1RA) 10 µg/ml was used to investigate the mechanism of C3a- and C5a-induced TEMT. Electron microscopy was used to observe the morphological changes. Immunocytochemistry staining, real-time PCR and Western blotting were used to detect the expressions of a smooth muscle actin (α-SMA), E-cadherin, Col-I, C3a receptor (C3aR), C5aR, CTGF and TGF-β1.</p><p><b>RESULTS</b>HK-2 cells cultured with C3a and C5a for 72 hours exhibited strong staining of α-SMA, lost the positive staining of E-cadherin, and showed a slightly spindle-like shape and loss of microvilli on the cell surface. The expressions of α-SMA, E-cadherin, Col-I, C3aR, C5aR, TGF-β1 and CTGF in C3a- and C5a-treated groups were higher than normal control group (P < 0.05). C3aRA and C5aRA inhibited the expressions of α-SMA, Col-I, C3aR, C5aR, and up-regulated the expression of E-cadherin (P < 0.05). TGF-β1 and CTGF mRNA expressions induced by C3a and C5a were partly blocked by TGF-β1RA (P < 0.05).</p><p><b>CONCLUSION</b>C3a and C5a can induce TEMT via the up-regulations of C3aR and C5aR mRNA and the activation of TGF-β1/CTGF signaling pathway in vitro.</p>

Establishment and evaluation of experimental sepsis mouse model / 中国实验血液学杂志

After treating with chemotherapy or immunosuppressant, malignant diseases of hematopoietic system such as leukemia, malignant lymphoma and aplastic anemia usually induced severe infection such as sepsis. Sepsis which is hard to be diagnosed causes high death rate. This study was purposed to establish an experimental sepsis mouse model so as to provide a basis for pathogenesis and intervention study. A classic caecal ligation and puncture (CLP) was used to establish experimental sepsis model. ELISA was used to detect levels of C5a, IL-6, TNFalpha, and IFN-gamma. Flow Cytometry was applied to measure apoptosis of lymphocytes in thymus and mesentery. The pathologic changes of thymus and spleen were confirmed by HE staining. The results showed that almost 70%-80% mice died at 72 hours after CLP. Only approximate 20% animal survived during finite time, mice in CLP group had significant weight lose. Meanwhile large release of different inflammatory mediators which are related with sepsis (C5a, IL-6, TNF-alpha, and IFN-gamma) was observed after CLP. Apoptosis of lymphocytes in thymus and mesentery lymphonodus was enhanced markedly after CLP. Significantly pathologic injury was also observed in thymus and spleen. It is concluded that a mouse model of experimental sepsis was successfully established by caecal ligation and puncture which can well mimic the clinical symptom of sepsis. The experimental sepsis mouse model provides an excellent tool for exploring the pathogenesis and intervention ways for sepsis accompanied with complicated malignant hematological diseases in vivo.

Regulation of tyrosylprotein sulfotransferases activity by sulfotyrosine / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the role of sulfated tyrosine in regulating the activity of tyrosylprotein sulfotransferases (TPST) 1 and TPST2.</p><p><b>METHODS</b>Constructs of TPST 1 and TPST2 were amplified by polymerase chain reaction (PCR), then fused into immunoglobulin G1 Fc region. All the variants in which sulfated tyrosines were mutated to phenylalanine were made by the PCR-based Quick Change method and confirmed by sequencing the entire reading frame. Small hairpin RNA (shRNA) constructs-targeting nucleotides 259-275 of TPST1 and nucleotides 73-94 of TPST2 were generated and subcloned into pBluescript. Human embryonic kidney (HEK) 293T cells were transfected with these plasmids. One day later, cells were split: one part was labeled with 35S-cysteine and methionine or 35S-Na2SO3 overnight, the second part was used for 125I labeled binding experiment, and the third part was retained for binding and flow cytometry.</p><p><b>RESULTS</b>Tyrosines at position 326 of TPST1 and position 325 of TPST2 were sulfated posttranslationally. Tyrosine sulfation of TPSTs was effectively inhibited by sulfation inhibitors, including specific shRNAs and non-specific NaCIO3. shRNAs reduced the sulfation of C3a receptor and C5a receptor, and partially blocked the binding of these two receptors to their respective ligands.</p><p><b>CONCLUSIONS</b>The activities of TPSTs were regulated by tyrosine sulfation. Inhibition of sulfotyrosine decreases the binding ability of C3a receptor and C5a receptor to their respective ligands.</p>

Chemotaxis of Blood Neutrophils from Patients with Primary Ciliary Dyskinesia

Primary ciliary dyskinesia is characterized by chronic upper and lower respiratory infections which are caused by the grossly impaired ciliary transport. Since the cilia and neutrophils both utilize microtubular system for their movement, it has been speculated that neutrophil motility such as chemotaxis might be impaired in patients with primary ciliary dyskinesia. Neutrophils were purified from whole blood from 16 patients with primary ciliary dyskinesia and from 15 healthy controls. Chemotactic responses of neutrophils to leukotriene B4 (LTB4), complement 5a (C5a), and formylmethion-ylleucylphenylalanine (fMLP) were examined using the under agarose method. The chemotactic differentials in response to LTB4, C5a, and fMLP in neutrophils from the patient group were significantly lower than the corresponding values in neutrophils from the control group (p<0.05 for all comparisons). The difference in chemotactic index between the two groups was statistically significant for LTB4 and fMLP (p<0.05 for both comparisons), but not for C5a (p=0.20). Neutrophils from patients with primary ciliary dyskinesia showed a decreased chemotactic response as compared with those from normal subjects. It is concluded that the increased frequency of respiratory tract infection in patients with primary ciliary dyskinesia is possibly due to the defective directional migration of neutrophils, as well as to the defective mucociliary clearance of the airways.

The role of C5a in adhesion properties of polymorphonuclear leukocyte to pulmonary vascular endothelial cells in burn patients with acute lung injury / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore the postburn adhesion properties of polymorphonuclear leukocyte (PMN) onto pulmonary vascular endothelial cells (PVEC) in burn patients with acute lung injury (ALI), so as to determine the role of C5a on PVEC-PMN adhesion.</p><p><b>METHODS</b>Microtubule sucking technique was employed to determine the PVEC-PMN adhesion. The myeloperoxidase (MPO) was also assayed to reflect the magnitude of PVEC-PMN adhesion.</p><p><b>RESULTS</b>The magnitude of PVEC-PMN adhesion increased and the adhesion force increased along with an increase in rh-C5a concentration. Simultaneously, the MPO activity was increased, which could be inhibited by anti-C5aR McAb in a concentration 1:104.</p><p><b>CONCLUSION</b>Both C5a and C5aR participated in PVEC-PMN adhesion, which might be important in the pathogenesis of ALI.</p>

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.

Tetrachloroauric acide depresses the activation processes of phagocytic cells

Gold compounds depress phagocytic cell responses, including chemotaxis, and respiratory burst. However, the effects of gold compounds on the function of phagocytic cells are variable according to the preparation of medicine. In this study, effect of tetrachloroauric acid on activated neutrophil responses, including respiratory burst, lysosomal enzyme release and change of intracellular Ca2+ level and on the synthesis of interleukin-8 and granulocyte-macrophage colony stimulating factor by macrophages was studied. This study further examines how gold compounds affect the activation processes. The respiratory burst stimulated by complement C5a, degraded IgG and PMA in neutrophils was inhibited by tetrachloroauric acid. In contrast to C5a and degraded IgG, PMA-stimulated superoxide production was weakly inhibited by tetrachloroauric acid. Staurosporine, genistein, EGTA and verapamil inhibited superoxide and H2O2 production caused by C5a and degraded IgG. PMA-stimulated superoxide production was inhibited by staurosporine but was not affected by genistein. Tetrachloroauric acid, genistein, EGTA and verapamil inhibited the release of acid phosphatase and myeloperoxidase, while the effect of staurosporine was not detected. The synthesis of interleukin-8 and granulocyte-macrophage colony stimulating factor by interleukin-1beta in macrophages was inhibited by tetrachloroauric acid. Preincubation with tetrachloroauric acid, genistein, EGTA and verapamil, the elevation of (Ca2+)i evoked by C5a was inhibited. Store-regulated Ca2+ entry in thapsigargin-pretreated neutrophils was decreased by the addition of tetrachloroauric acid and genistein. The effect of staurosporine on intracellular Ca2+ mobilization was not observed. In conclusion, tetrachloroauric acid may suppress neutrophil responses through its inhibitory action on elevation of intracellular Ca2+ level and protein kinase C. It might exhibit an inhibitory effect on the action of protein tyrosine kinase. Tetrachloroauric acid depresses cytokine production by macrophages.

Complement and dengue haemorrhagic fever/shock syndrome.

The complement system is activated in DHF/DSS. The peak of activation and the presence of C3a and C5a anaphylatoxins coincided with the onset of shock and leakage. The levels of C3a correlated well with disease severity. This indicated an important role of the complement system in the pathogenesis of shock. Circulating immune complexes as assayed by two standard techniques were not detected in the majority of patients, and if detected were found in small amount. The role of circulating immune complexes in the activation of complement in DHF/DSS needs to be reinvestigated, and other possible mechanisms leading to complement activation should be sought.