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.
Animals ; Cell Differentiation/physiology* ; Cells, Cultured ; Complement C5a/metabolism* ; Dental Pulp/physiology* ; Dentin ; Mice ; Receptor, Anaphylatoxin C5a ; Stem 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.
Adenosine ; Animals ; Complement C5a* ; Complement System Proteins* ; Cyclic AMP-Dependent Protein Kinases ; Mice ; Mice, Knockout ; Phenobarbital ; Receptor, Anaphylatoxin C5a* ; Toll-Like Receptors* ; Yersinia enterocolitica* ; Yersinia*

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.
Adult ; Alcoholism ; Complement C5a ; Hospitalization ; Humans ; Pancreatitis* ; Peptide Hydrolases ; Retinaldehyde ; Trypsin

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.
Calmodulin* ; Chlorpromazine ; Complement C5a ; Complement System Proteins* ; Cytosol ; Depression* ; Egtazic Acid ; Genistein ; Imipramine ; Neutrophils* ; Peroxidase ; Staurosporine ; Superoxides ; Trifluoperazine ; Verapamil

OBJECTIVETo investigate the role of sulfated tyrosine in regulating the activity of tyrosylprotein sulfotransferases (TPST) 1 and TPST2.

METHODSConstructs 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.

RESULTSTyrosines 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.

CONCLUSIONSThe 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.

Cell Line ; Complement C3a ; metabolism ; Complement C5a ; metabolism ; Humans ; Protein Binding ; Protein Processing, Post-Translational ; Receptor, Anaphylatoxin C5a ; metabolism ; Receptors, Complement ; metabolism ; Sulfotransferases ; genetics ; metabolism ; Transfection ; Tyrosine ; analogs & derivatives ; metabolism

OBJECTIVETo 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.

METHODSSixty-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.

RESULTSThe 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).

CONCLUSIONTCE 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.

Animals ; Blood Urea Nitrogen ; Complement C3a ; metabolism ; Complement C5a ; metabolism ; Creatinine ; blood ; Female ; Kidney ; metabolism ; pathology ; Mice ; Mice, Inbred BALB C ; Trichloroethylene ; toxicity

OBJECTIVETo study the expression of C3aR and C5aR in trichloroethylene-sensitized mouse liver injury and discuss the pathogenesis of Dermatitis Medicamentosa-like of TCE (DMLT).

METHODS6∼8 w female BALB/c mouse were randomly divided into blank control group, solvent control group and TCE treatment group. TCE was given to the mouse for sensitization at 1th, 4th, 7th, 10th day and challenge at 17th day and 19th day. Before killing mouse, liver weight and body weight were recorded. The livers were separated at 24 h, 48 h, 72 h and 7 d after challenge. And the liver sections were used for immunofluorescence stain and RT-PCR to detect the expression levels of C3aR and C5aR.

RESULTSMicroscopic examination showed no significant change in liver structure or organization in TCE non-sensitized group, while liver cell oedema, cell necrosis and inflammatory cell infiltration were clearly observed in TCE-sensitized groups. The expression levels of C3aR and C5aR in 24 h, 48 h, 72 h and 7 d TCE-sensitized groups were significant higher than blank control group, solvent control group and related TCE non-sensitized groups (P < 0.05).

CONCLUSIONComplement activation was involved in TCE-induced liver injury and C3aR and C5aR might play essential role in the process.

Animals ; Chemical and Drug Induced Liver Injury ; Dermatitis, Occupational ; Edema ; Female ; Liver ; physiopathology ; Mice ; Mice, Inbred BALB C ; Receptor, Anaphylatoxin C5a ; metabolism ; Receptors, Complement ; metabolism ; Solvents ; toxicity ; Trichloroethylene ; toxicity

OBJECTIVETo 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.

METHODSMicrotubule sucking technique was employed to determine the PVEC-PMN adhesion. The myeloperoxidase (MPO) was also assayed to reflect the magnitude of PVEC-PMN adhesion.

RESULTSThe 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.

CONCLUSIONBoth C5a and C5aR participated in PVEC-PMN adhesion, which might be important in the pathogenesis of ALI.

Acute Disease ; Antibodies, Monoclonal ; pharmacology ; Antigens, CD ; immunology ; Burns ; blood ; complications ; Cell Adhesion ; drug effects ; Cells, Cultured ; Complement C5a ; pharmacology ; Dose-Response Relationship, Drug ; Endothelium, Vascular ; cytology ; drug effects ; Fetus ; Humans ; Lung ; Lung Diseases ; complications ; Neutrophils ; cytology ; drug effects ; enzymology ; Peroxidase ; antagonists & inhibitors ; drug effects ; metabolism ; Receptor, Anaphylatoxin C5a ; Receptors, Complement ; immunology

BACKGROUNDTubulointerstitial 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.

METHODSHK-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.

RESULTSHK-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).

CONCLUSIONC3a 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.

Blotting, Western ; Cadherins ; genetics ; Cell Line ; Cell Transdifferentiation ; drug effects ; Complement C3a ; pharmacology ; Complement C5a ; pharmacology ; Epithelial Cells ; cytology ; drug effects ; ultrastructure ; Humans ; Immunohistochemistry ; Microscopy, Electron, Scanning ; Myofibroblasts ; cytology ; drug effects ; ultrastructure ; Real-Time Polymerase Chain Reaction

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.
Animals ; Apoptosis ; Cecum ; injuries ; Complement C5a ; metabolism ; Disease Models, Animal ; Interferon-gamma ; metabolism ; Interleukin-6 ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Sepsis ; metabolism ; pathology ; Spleen ; pathology ; Thymus Gland ; pathology ; Tumor Necrosis Factor-alpha ; metabolism