Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 640
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Invest Ophthalmol Vis Sci ; 60(12): 3813-3820, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31525777

RESUMO

Purpose: To determine whether elevated levels of immune/inflammatory proteins in cord blood, alone or in combination with conventional clinical parameters, can predict the occurrence and progression of retinopathy of prematurity (ROP) in preterm infants. Methods: This was a retrospective cohort study of 110 premature singleton infants who were born at ≤32.0 weeks. Cord plasma at birth was assayed for interleukin-6, C3a, C5a, matrix metalloproteinase-2 (MMP-2), MMP-9, tissue inhibitor of metalloproteinase-1, macrophage colony-stimulating factor, endostatin, a proliferation-inducing ligand, insulin-like growth factor-binding protein-1 (IGFBP-1), IGFBP-2, and calcium-binding protein A8/A9 complex levels. The primary outcome measures were the occurrence of any stage ROP, severe ROP (>stage 3), and vision-threatening type 1 ROP requiring laser treatment. Results: ROP was diagnosed in 30 of 110 infants (27.3%), including 14 (12.7%) with severe ROP. Laser treatment was performed on 7 infants (6.4%). Multiple logistic regression analyses indicated that elevated levels of cord plasma IL-6 were significantly associated with severe ROP, whereas elevated levels of cord plasma C5a were significantly associated with ROP laser treatments. However, none of the proteins measured in the cord plasma were associated with ROP occurrence. Using a stepwise regression procedure, we developed a combined prediction model, which included high cord plasma IL-6 levels and low birth weight for severe ROP (area under the curve [AUC], 0.840), and high cord plasma C5a levels and low birth weight for laser treatment (AUC, 0.884). Conclusions: Elevated levels of cord plasma IL-6 and C5a could be used as independent markers to predict severe ROP and laser treatment, respectively, with combined models predicting ROP progression with good accuracy.


Assuntos
Biomarcadores/sangue , Complemento C5a/metabolismo , Sangue Fetal/metabolismo , Recém-Nascido Prematuro , Interleucina-6/sangue , Retinopatia da Prematuridade/diagnóstico , Complemento C3a/metabolismo , Citocinas/sangue , Progressão da Doença , Ensaio de Imunoadsorção Enzimática , Feminino , Idade Gestacional , Humanos , Lactente , Recém-Nascido de Baixo Peso , Recém-Nascido , Fotocoagulação a Laser , Masculino , Metaloproteases/sangue , Nascimento Prematuro , Retinopatia da Prematuridade/sangue , Retinopatia da Prematuridade/cirurgia , Estudos Retrospectivos
2.
Int J Mol Med ; 44(3): 823-834, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31257457

RESUMO

Clinically, deep decay can lead to inflammation in the dental pulp. Apart from the use of various materials to sooth the inflamed pulp, there is currently no adequate treatment, and the gold standard, calcium hydroxide, that is used to cover the dentin/pulp, has limited effect. Sometimes the pulp will remain infected and cause pulpitis, and ultimately, the pulp will need to be removed. The first principle of oral treatment is to protect the pulp. Therefore, it is necessary to study the immune response and regeneration of pulp cells in conditions of deep decay. Of the terminal complement system proteins, complement 5a (C5a) has the most potent effect compared to complement 3a (C3a) and complement 4a (C4a). C5a is 20- to 2,500-fold stronger than C3a and C4a. The purpose of this study was to elucidate the association between C5a, secreted by complement activation, and the duration of inflammation. Another key goal was to detect the expression of C5a and its receptor, complement 5a receptor (C5aR). To this end, the cells were divided into 4 groups as per stimulation with lipoteichoic acid (LTA) or lipopolysaccharide (LPS) as follows: i) The 1 µg/ml LTA group; ii) the 1 µg/ml LPS group; iii) the 1 µg/ml LTA and 1 µg/ml LPS group; and iv) the PBS-only group, which served as a control. There were 5 time points for all 4 groups: 1, 2, 3, 5 and 7 days. Reverse transcription-quantitative polymerase chain reaction was used to detect the gene expression levels of C5a, C5aR and interleukin (IL)-6 at different time points. Western blot analyses was carried out to detect the expression of C5aR. Transmission electron microscopy was also conducted to assess the ultrastructural features of dental pulp cells. The gene expression trends of C5a and C5aR mRNA were identical. C5a and C5aR mRNA was highly expressed on the second day of LTA or LPS stimulation. However, in the LTA and LPS co-stimulation group, C5a and C5aR mRNA were highly expressed on both the first and second day, with higher levels on the second day. IL-6 expression decreased as time progressed in the LTA only and in the LTA + LPS co-stimulation groups. However, a peak in its expression was observed on the second day in the LPS group. On the whole, this study demonstrates that a 1 µg/ml concentration of LTA and LPS stimulates human dental pulp cells to activate the expression of C5a.


Assuntos
Complemento C5a/genética , Complemento C5a/imunologia , Polpa Dentária/citologia , Polpa Dentária/metabolismo , Regulação da Expressão Gênica , Receptor da Anafilatoxina C5a/genética , Receptor da Anafilatoxina C5a/imunologia , Células-Tronco/metabolismo , Adipócitos/metabolismo , Adolescente , Adulto , Biomarcadores , Diferenciação Celular , Células Cultivadas , Complemento C5a/metabolismo , Citocinas/metabolismo , Feminino , Humanos , Lipopolissacarídeos/imunologia , Masculino , Osteoblastos/citologia , Osteoblastos/metabolismo , Receptor da Anafilatoxina C5a/metabolismo , Células-Tronco/imunologia , Ácidos Teicoicos/imunologia , Adulto Jovem
3.
Biomed Res Int ; 2019: 4805853, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31111056

RESUMO

N-acetylcysteine has been widely used as a nutritional supplement and drug in humans for its antioxidant properties. The complement activation fragment C5a is a strong proinflammatory molecule that mediates cell adhesion, chemotaxis, and the complex biological functions. However, the effect of NAC on the C5a, and the relationship of those two with cisplatin-induced acute kidney injury are unknown. In cisplatin induced AKI mouse model, mice with NAC administration had a marked improvement in renal function (BUN and Cr), decreased pathological damage, reduced inflammation, and alleviated renal oxidative stress. Furthermore, C5a and C5aR expression in the cisplatin-treated group was notably increased compared with the control group, and this increase could be significantly inhibited by NAC. In addition, neutrophils coexpressed distinctly with C5aR, and the number of infiltrating neutrophils (MPO+ly6G+) and inflammatory factors decreased with NAC treatment in the cisplatin-treated group. Overall, these data demonstrate that NAC could ameliorate cisplatin-induced nephrotoxicity in mice and the protective effects may be conducted by inhibiting the activation of kidney inflammation and the complement system.


Assuntos
Acetilcisteína/farmacologia , Lesão Renal Aguda/tratamento farmacológico , Cisplatino/efeitos adversos , Receptor da Anafilatoxina C5a/antagonistas & inibidores , Animais , Apoptose/efeitos dos fármacos , Complemento C5a/metabolismo , Modelos Animais de Doenças , Inflamação , Rim/efeitos dos fármacos , Rim/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos , Estresse Oxidativo/efeitos dos fármacos , Receptor da Anafilatoxina C5a/metabolismo
4.
J Biol Chem ; 294(24): 9416-9429, 2019 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-31036565

RESUMO

The human complement component, C5a, binds two different seven-transmembrane receptors termed C5aR1 and C5aR2. C5aR1 is a prototypical G-protein-coupled receptor that couples to the Gαi subfamily of heterotrimeric G-proteins and ß-arrestins (ßarrs) following C5a stimulation. Peptide fragments derived from the C terminus of C5a can still interact with the receptor, albeit with lower affinity, and can act as agonists or antagonists. However, whether such fragments might display ligand bias at C5aR1 remains unexplored. Here, we compare C5a and a modified C-terminal fragment of C5a, C5apep, in terms of G-protein coupling, ßarr recruitment, endocytosis, and extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase activation at the human C5aR1. We discover that C5apep acts as a full agonist for Gαi coupling as measured by cAMP response and extracellular signal-regulated kinase 1/2 phosphorylation, but it displays partial agonism for ßarr recruitment and receptor endocytosis. Interestingly, C5apep exhibits full-agonist efficacy with respect to inhibiting lipopolysaccharide-induced interleukin-6 secretion in human macrophages, but its ability to induce human neutrophil migration is substantially lower compared with C5a, although both these responses are sensitive to pertussis toxin treatment. Taken together, our data reveal that compared with C5a, C5apep exerts partial efficacy for ßarr recruitment, receptor trafficking, and neutrophil migration. Our findings therefore uncover functional bias at C5aR1 and also provide a framework that can potentially be extended to chemokine receptors, which also typically interact with chemokines through a biphasic mechanism.


Assuntos
Complemento C5a/metabolismo , Endocitose , Receptor da Anafilatoxina C5a/metabolismo , beta-Arrestinas/metabolismo , Sequência de Aminoácidos , Movimento Celular , Complemento C5a/genética , Células HEK293 , Humanos , Interleucina-6/genética , Interleucina-6/metabolismo , Macrófagos/citologia , Macrófagos/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Neutrófilos/metabolismo , Fosforilação , Ligação Proteica , Receptor da Anafilatoxina C5a/genética , Homologia de Sequência , Transdução de Sinais , beta-Arrestinas/genética
5.
Semin Thromb Hemost ; 45(4): 348-353, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31041804

RESUMO

Thrombotic microangiopathy (TMA) is a rare but often devastating complication of cancer and cancer treatment. The syndrome is defined by thrombocytopenia (i.e., a platelet count of < 150,000/mcL or > 30% decrease from baseline), microangiopathic hemolytic anemia, and some evidence of organ damage. Among the nine recognized groups of disorders causing TMA, the focus of this article will be on cancer and cancer treatment-related causes of TMA. This review will discuss the pathophysiology of TMA in cancer, chemotherapy-associated TMA, transplant-associated TMA, and newer therapeutic modalities.


Assuntos
Antineoplásicos/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Neoplasias/terapia , Microangiopatias Trombóticas/diagnóstico , Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos/uso terapêutico , Complemento C5a/antagonistas & inibidores , Complemento C5a/metabolismo , Inativadores do Complemento/uso terapêutico , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Neoplasias/complicações , Contagem de Plaquetas , Trombocitopenia/diagnóstico , Trombocitopenia/tratamento farmacológico , Trombocitopenia/etiologia , Microangiopatias Trombóticas/tratamento farmacológico , Microangiopatias Trombóticas/etiologia
6.
J Biol Chem ; 294(21): 8384-8394, 2019 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-30971430

RESUMO

The NLR family pyrin domain-containing 3 (NLRP3) inflammasome is a multimeric protein complex that mediates maturation of the cytokines IL-1ß and IL-18 as well as release of the proinflammatory protein high-mobility group box 1 (HMGB1) and contributes to several inflammatory diseases, including sepsis, gout, and type 2 diabetes. In this context, the well-studied active complement fragment C5a and its receptor C5aR1 or C5aR2 orchestrate the inflammatory responses in many diseases. Although a C5a-C5aR interaction in NLRP3-associated diseases has been suggested, little is known about the details of C5a-C5aR cross-talk with the NLRP3 inflammasome in macrophages. In this study, using mice and murine macrophages and cytokines, immunoblotting, siRNA, and quantitative real-time PCR assays, we demonstrate that C5aR2 deficiency restricts activation of the NLRP3 inflammasome and release of HMGB1 both in vitro and in vivo Mechanistically, we found that C5aR2 promotes NLRP3 activation by amplifying dsRNA-dependent PKR expression, which is an important NLRP3-activating factor. We also observed that elevation of PKR expression because of the C5a-C5aR2 interaction depends on the mitogen-activated protein kinase/extracellular signal-regulated kinase kinase pathway and type I IFN signaling. In conclusion, these findings reveal that C5aR2 contributes to NLRP3 inflammasome activation and HMGB1 release from macrophages.


Assuntos
Regulação Enzimológica da Expressão Gênica , Proteína HMGB1/metabolismo , Inflamassomos/metabolismo , Macrófagos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Receptor da Anafilatoxina C5a/metabolismo , eIF-2 Quinase/biossíntese , Animais , Complemento C5a/genética , Complemento C5a/metabolismo , Proteína HMGB1/genética , Inflamassomos/genética , Camundongos , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Receptor da Anafilatoxina C5a/genética , eIF-2 Quinase/genética
7.
Neurotox Res ; 36(1): 163-174, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30953275

RESUMO

The central nervous system (CNS) constitutively expresses complement (C) membrane receptors and complement proteins, including the component C5a. This is a crucial terminal effector of the C cascade, mostly involved in pain and neuroinflammatory conditions. Aberrant activation of C5a protein and its receptor C5aR has been reported to play a critical role in neurodegenerative diseases, with important clinical consequences. Here we have investigated the effects of DF3016A, a novel selective C5aR antagonist, able to penetrate the blood-brain barrier (BBB), on cortical neurons exposed to oxygen-glucose deprivation-reoxygenation (OGD/R), a neuroinflammation-related process. We demonstrated that a mild ischemic insult induces an early upregulation of C5aR associated with the over-production of pro-inflammatory cytokines and the over-expression of the transcriptional regulatory factor miR-181. Furthermore, we report the first experimental evidence of the effect of DF3016A, modulating complement component C5a, on neurons in a model of injury. Interestingly, DF3016A protects neuronal viability by restoring intracellular calcium levels, thus opposing the increase in pro-inflammatory cytokine levels and miR-181 expression. Based on our results, we suggest that DF3016A is a novel C5aR antagonist promoting protective effects against OGD/R-induced damage that could be a new therapeutic approach to controlling CNS neuroinflammatory conditions.


Assuntos
Isquemia Encefálica/complicações , Encefalite/prevenção & controle , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Receptor da Anafilatoxina C5a/antagonistas & inibidores , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Complemento C5a/metabolismo , Encefalite/etiologia , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Camundongos Endogâmicos BALB C , MicroRNAs/metabolismo , Receptor da Anafilatoxina C5a/metabolismo
8.
Clin Perinatol ; 46(1): 1-17, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30771811

RESUMO

Necrotizing enterocolitis (NEC) is a devastating disease of prematurity, with no current method for early diagnosis. Diagnosis is particularly challenging, frequently occurring after the disease has progressed to the point of significant and often irreversible intestinal damage. Biomarker research has tremendous potential to advance clinical management of NEC and our understanding of its pathogenesis. This review discusses the need for novel biomarkers in NEC management, evaluates studies investigating such biomarkers, and explains the difficulties associated with translating biomarker discovery into clinical use.


Assuntos
Biomarcadores/metabolismo , Enterocolite Necrosante/metabolismo , alfa-Globulinas/metabolismo , Contagem de Células Sanguíneas , Testes Respiratórios , Proteína C-Reativa/metabolismo , Claudinas/metabolismo , Complemento C5a/metabolismo , Citocinas/metabolismo , Diagnóstico Precoce , Enterocolite Necrosante/diagnóstico , Enterocolite Necrosante/microbiologia , Fator de Crescimento Epidérmico/metabolismo , Proteínas de Ligação a Ácido Graxo/metabolismo , Microbioma Gastrointestinal , Genômica , Humanos , Hidrogênio/metabolismo , Recém-Nascido , Recém-Nascido Prematuro , Complexo Antígeno L1 Leucocitário/metabolismo , Metabolômica , Fator de Ativação de Plaquetas/metabolismo , Pró-Calcitonina/metabolismo , Prognóstico , Proteômica , Medição de Risco , Proteína S100A12/metabolismo , Sensibilidade e Especificidade , Albumina Sérica Humana/metabolismo , Proteína Amiloide A Sérica/metabolismo , Espectroscopia de Luz Próxima ao Infravermelho , Fator Trefoil-3/metabolismo , Ultrassonografia , Compostos Orgânicos Voláteis
9.
Nat Immunol ; 20(2): 141-151, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30643265

RESUMO

Rheumatoid arthritis is characterized by progressive joint inflammation and affects ~1% of the human population. We noted single-nucleotide polymorphisms (SNPs) in the apoptotic cell-engulfment genes ELMO1, DOCK2, and RAC1 linked to rheumatoid arthritis. As ELMO1 promotes cytoskeletal reorganization during engulfment, we hypothesized that ELMO1 loss would worsen inflammatory arthritis. Surprisingly, Elmo1-deficient mice showed reduced joint inflammation in acute and chronic arthritis models. Genetic and cell-biology studies revealed that ELMO1 associates with receptors linked to neutrophil function in arthritis and regulates activation and early neutrophil recruitment to the joints, without general inhibition of inflammatory responses. Further, neutrophils from the peripheral blood of human donors that carry the SNP in ELMO1 associated with arthritis display increased migratory capacity, whereas ELMO1 knockdown reduces human neutrophil migration to chemokines linked to arthritis. These data identify 'noncanonical' roles for ELMO1 as an important cytoplasmic regulator of specific neutrophil receptors and promoter of arthritis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/imunologia , Artrite Experimental/imunologia , Artrite Reumatoide/imunologia , Neutrófilos/imunologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Apoptose/imunologia , Artrite Experimental/diagnóstico , Artrite Experimental/genética , Artrite Experimental/patologia , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/genética , Artrite Reumatoide/patologia , Quimiotaxia/genética , Quimiotaxia/imunologia , Colágeno/imunologia , Complemento C5a/imunologia , Complemento C5a/metabolismo , Citoplasma/imunologia , Citoplasma/metabolismo , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Voluntários Saudáveis , Humanos , Microscopia Intravital , Articulações/citologia , Articulações/imunologia , Leucotrieno B4/imunologia , Leucotrieno B4/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neutrófilos/metabolismo , Polimorfismo de Nucleotídeo Único , Proteômica , Índice de Gravidade de Doença , Transdução de Sinais/imunologia , Imagem com Lapso de Tempo
10.
Semin Cell Dev Biol ; 85: 153-163, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29155219

RESUMO

Recent insights into the role of complement anaphylatoxins C3a and C5a in cancer provide new opportunities for the development of innovative biomarkers and therapeutic strategies. These two complement activation products can maintain chronic inflammation, promote an immunosuppressive microenvironment, induce angiogenesis, and increase the motility and metastatic potential of cancer cells. Still, the diverse heterogeneity of responses mediated by these peptides poses a challenge both to our understanding of the role played by these molecules in cancer progression and to the development of effective treatments. This review attempts to summarize the evidence surrounding the involvement of anaphylatoxins in the biological contexts associated with tumor progression. We also describe the recent developments that support the inhibition of anaphylatoxins, or their cognate receptors C3aR and C5aR1, as a treatment option for maximizing the clinical efficacy of current immunotherapies that target the PD-1/PD-L1 immune checkpoint.


Assuntos
Complemento C3a/metabolismo , Complemento C5a/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Animais , Humanos , Neoplasias/patologia
11.
Eur Rev Med Pharmacol Sci ; 22(22): 7994-8003, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30536348

RESUMO

OBJECTIVE: To discuss the effect of complement C52 (C5a) and complement C5a receptor (C5aR) antagonists on inflammatory status of mouse microglial cells. MATERIALS AND METHODS: Primary culture was performed on mouse microglial cells. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay was used to detect effect of C5a and C5aR antagonists on vitality of microglial cells. The effect of C5a and C5aR antagonists on mRNA expression of p38MAPK and ERK1/2 was determined using quantitative PCR (qPCR). Enzyme linked immunosorbent assay (ELISA) was used to measure expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in cells. RESULTS: According to quantitative fluorescent PCR, relative expression of p38MAPK and ERK1/2 mRNA in C5a antagonist treatment group was significantly higher compared to normal group and C5a+C5aR antagonist treatment group (p<0.05). However, the relative expression of the C5a+C5aR antagonist treatment group was significantly lower compared to that of the normal group (p<0.05). Expression of Iba1, p-p38MAPK and p-ERK1/2 proteins in C5a antagonist treatment group was significantly higher than normal group, in C5a+C5aR antagonist treatment group was lower than C5a antagonist treatment group (p<0.05). There were significant differences for IL-6 and TNF-α levels among 5 groups (p<0.05). Expression of cytokines was the highest in 100 nM C5a antagonist treatments and lowest in normal group. CONCLUSIONS: Complement C5a upregulated expression of inflammatory factors in mouse microglial cells, while C5aR antagonist inhibited occurrence and progression of inflammatory status. This was achieved by affecting transcriptional and translational processes of different factors in p38MAPK and ERK1/2 signaling pathway.


Assuntos
Complemento C5a/metabolismo , Mediadores da Inflamação/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Microglia/metabolismo , Receptor da Anafilatoxina C5a/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Animais Recém-Nascidos , Células Cultivadas , Mediadores da Inflamação/antagonistas & inibidores , Camundongos , Microglia/efeitos dos fármacos , Peptídeos Cíclicos/farmacologia , Receptor da Anafilatoxina C5a/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
12.
Arthritis Res Ther ; 20(1): 247, 2018 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-30390695

RESUMO

BACKGROUND: Epidemiological evidence to suggest that periodontal disease (PD) is involved in the progression of rheumatoid arthritis (RA) is increasing. The complement system plays a critical role in immune responses. C5a has been implicated in chronic inflammatory diseases, including PD and RA. Porphyromonas gingivalis is the major causative bacteria of PD and can produce C5a. Therefore, it is hypothesized that P. gingivalis infection is involved in the progression of RA by elevating C5a levels. In the present study, P. gingivalis-infected RA model mice were established to investigate the involvement of C5a. METHODS: SKG mice orally infected with P. gingivalis were immunized with intraperitoneal injection of laminarin (LA) to induce arthritis. Arthritis development was assessed by arthritis score (AS), bone destruction on the talus, histology, and serum markers of RA. In order to investigate the effects of serum C5a on bone destruction, osteoclast differentiation of bone marrow mononuclear cells was examined by using serum samples from each group of mice. The relationship between C5a levels and antibody titers to periodontal pathogens in patients with RA was investigated by enzyme-linked immunosorbent assay. RESULTS: P. gingivalis oral infection increased AS, infiltration of inflammatory cells, bone destruction on the talus, and serum markers of RA in mice immunized with LA. The addition of serum from LA-injected mice with the P. gingivalis oral infection promoted osteoclast differentiation, and the addition of a neutralization antibody against C5a suppressed osteoclast differentiation. C5a levels of serum in RA patients with positive P. gingivalis antibody were elevated compared with those in RA patients with negative P. gingivalis antibody. CONCLUSIONS: These results suggest that P. gingivalis infection enhances the progression of RA via C5a.


Assuntos
Artrite Experimental/sangue , Artrite Experimental/diagnóstico por imagem , Infecções por Bacteroidaceae/sangue , Infecções por Bacteroidaceae/diagnóstico por imagem , Complemento C5a/metabolismo , Porphyromonas gingivalis/isolamento & purificação , Animais , Diferenciação Celular/fisiologia , Células Cultivadas , Progressão da Doença , Feminino , Humanos , Camundongos , Microtomografia por Raio-X/tendências
13.
Mediators Inflamm ; 2018: 4209359, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30327582

RESUMO

Objective: We aimed to determine whether elevated levels of various inflammatory and immune proteins in umbilical cord blood are associated with an increased risk of newborn hearing screening (NHS) test failure in preterm neonates. Methods: This retrospective cohort study included 127 premature singleton infants who were born at ≤33.6 weeks. Umbilical cord plasma at birth was assayed for interleukin (IL)-6, complement C3a and C5a, matrix metalloproteinase (MMP)-9, macrophage colony-stimulating factor (M-CSF), and endostatin levels using ELISA kits. Neonatal blood C-reactive protein (CRP) levels were measured within 2 hours of birth. The primary outcome measure was a uni- or bilateral refer result on an NHS test. Univariate and multivariate analyses were applied. Results: Fifteen (11.8%) infants failed the NHS test. In the univariate analyses, high IL-6 and low C3a levels in umbilical cord plasma, funisitis, and an elevated CRP level (>5 mg/L) in the immediate postnatal period were significantly associated with NHS test failure. However, the levels of umbilical cord plasma MMP-9, C5a, M-CSF, and endostatin were not significantly different between infants who passed and those who failed the NHS test. Multiple logistic regression analyses indicated that elevated umbilical cord plasma C3a levels were independently associated with a reduced risk of NHS test failure, whereas elevated levels of umbilical cord plasma IL-6 and high CRP levels in the immediate postnatal period were significantly associated with NHS test failure. Conclusions: Our data demonstrated that in preterm neonates, a systemic fetal inflammatory response reflected by umbilical cord plasma IL-6 and immediate postnatal CRP levels may contribute to the risk for NHS test failure, whereas the changes in complement activation fragments initiated in utero may have protective effect of hearing screen failure.


Assuntos
Sangue Fetal/metabolismo , Proteína C-Reativa/metabolismo , Complemento C3a/metabolismo , Complemento C5a/metabolismo , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro/sangue , Interleucina-6/metabolismo , Fator Estimulador de Colônias de Macrófagos/metabolismo , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Gravidez , Estudos Retrospectivos
14.
AAPS J ; 20(6): 106, 2018 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-30280286

RESUMO

Complement protein C5a is recognized as an important component of the alternative complement pathway. Its role is prominent enough to garner interest not only as a biomarker, but also as a potential therapeutic target. Bioanalytical challenges have been posed in proper quantitation of free C5a due to interference from its precursor, C5. Additionally, free therapeutic target quantitation can be difficult due to effects of sample dilution and prolonged sample incubation when therapeutic is used as capture reagent. Gyrolab technology enables quantitation of free target analyte with minimal sample dilution and rapid sample incubations, thus enabling in vitro results that are more representative of in vivo pharmacodynamics. When coupled with strategic sample pretreatment, Gyrolab offers an opportunity to quantitate free C5a in human plasma with an assay that vastly diminishes C5 interference. A Gyrolab assay for the quantitation of free C5a in human plasma was developed and validated. Validation results confirmed that proper sample pretreatment and use of the Gyrolab platform yield accurate and reliable results. Due to the advantages that it provides, Gyrolab has become our default technology of choice for quantitation of free target.


Assuntos
Métodos Analíticos de Preparação de Amostras/métodos , Bioensaio/métodos , Complemento C5a/análise , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais Humanizados/metabolismo , Bioensaio/instrumentação , Complemento C5a/imunologia , Complemento C5a/metabolismo , Inativadores do Complemento/imunologia , Inativadores do Complemento/metabolismo , Humanos , Imunoensaio/instrumentação , Imunoensaio/métodos , Limite de Detecção
15.
Mol Med Rep ; 18(5): 4523-4529, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30221740

RESUMO

Increasing evidence has demonstrated that complement activation is required for ischemia­reperfusion injury (IRI)­induced hepatic damage, and cobra venom factor (CVF) can deplete the complement components. The aim of the current study was to investigate the effect and intrinsic mechanism of CVF pretreatment on IRI­induced acute hepatic injury in rats. Acute hepatic injury in rats was induced by bone fracture to simulate trauma, followed by hemorrhage for 90 min, and then the rats were resuscitated for a period of 20 min of reperfusion. The survival times under different CVF treatment doses and schedules for rats with IRI were evaluated. Hepatic tissues and serum samples were analyzed for acute hepatic injury, complement activation, inflammatory mediator release and apoptosis at predetermined times and compared between the IRI group and the CVF pretreatment + IRI groups. Compared to the rats with IRI alone, the survival times were significantly improved among rats with IRI receiving a high­dose or low­dose CVF pretreatment (all P<0.01). Upon histological examination, severe hepatic damage was observed in the rats with IRI, accompanied by liver function deterioration, complement and membrane attack complex activation, inflammatory mediator release and hepatic cell apoptosis. CVF pretreatment significantly attenuated the hepatic injury through depletion of anaphylatoxic C5a and membrane attack complex C5b­9 activation, and subsequent inhibition of inflammatory mediator release and hepatic cell apoptosis (all P<0.05). The results indicated that CVF pretreatment ameliorates IRI­induced acute hepatic injury. However, further studies are required to determine whether this therapy could be a potential agent for the treatment of IRI injuries in clinical settings.


Assuntos
Venenos Elapídicos/administração & dosagem , Inflamação/tratamento farmacológico , Hepatopatias/tratamento farmacológico , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Ativação do Complemento/efeitos dos fármacos , Complemento C5a/efeitos dos fármacos , Complemento C5a/metabolismo , Complexo de Ataque à Membrana do Sistema Complemento/efeitos dos fármacos , Complexo de Ataque à Membrana do Sistema Complemento/metabolismo , Venenos Elapídicos/química , Fraturas Ósseas/complicações , Fraturas Ósseas/fisiopatologia , Humanos , Inflamação/complicações , Inflamação/fisiopatologia , Fígado/efeitos dos fármacos , Fígado/lesões , Fígado/fisiopatologia , Hepatopatias/complicações , Ratos , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/fisiopatologia
16.
Mol Cell Probes ; 41: 14-21, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30092352

RESUMO

C5a is an important pro-inflammatory peptide involved in complement activation, membrane attack complex formation, immune cell chemotaxis, and allergic responses. Osteoarthritis is a disease characterized by degenerative changes in articular cartilage. It has recently been found that inflammatory responses play an important role in the pathogenesis of osteoarthritis and also in rheumatoid arthritis, where dysfunctional synoviocytes are involved. We performed a series of studies to verify our hypothesis that inhibition of C5a would prevent IL-1ß-induced alternations in rat synoviocytes. In vitro studies were performed with RSC-364 cells to examine the role of C5a in the function of synoviocytes. RSC-364 cells (a rat derived synovial cell line) were treated with IL-1ß, IL-1ß+siC5a, IL-1ß+PMX205 that is antagonist of C5aR, or left untreated. Cell cycle, proliferation, apoptosis, invasion, as well as levels of C5a, IL-17A and TNF-α expression were evaluated. We found that IL-1ß could significantly increase the proliferation and invasion capabilities of RSC-364 cells, as well as of C5a IL-17A and TNF-α expression. In contrast, inhibition of C5a by siRNA or application of antagonist of C5aR PMX205 reversed the IL-1ß-induced changes in C5a expression, cell cycle, proliferation, apoptosis, invasion, and cytokines releases. Taken together, our study results suggest that IL-1ß can increase C5a expression in RSC-364 cells, and that C5a exerts a proinflammatory effect in RSC-364 cells. Inhibition of C5a might represent a new strategy for treating rheumatoid arthritis.


Assuntos
Complemento C5a/metabolismo , Interleucina-1beta/farmacologia , Sinoviócitos/metabolismo , Animais , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Ratos , Receptor da Anafilatoxina C5a/metabolismo , Sinoviócitos/efeitos dos fármacos
17.
J Am Heart Assoc ; 7(14)2018 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-30006493

RESUMO

BACKGROUND: Endothelial microparticles are associated with chronic kidney disease (CKD) and complement activation. We hypothesized that the complement pathway is activated in patients with CKD via endothelial microparticles and that complement activation correlates with endothelial dysfunction in CKD. METHODS AND RESULTS: We analyzed complement data of 30 healthy subjects, 30 patients with stage III/IV CKD, and 30 renal transplant recipients with stage III/IV CKD, evaluating the potential correlation of complement fragments with brachial artery flow-mediated dilation, Chronic Kidney Disease Epidemiology Collaboration glomerular filtration rate, and urinary albumin/creatinine ratio. Endothelial microparticles were characterized via proteomic analysis and compared between study groups. Complement fragment Ba was significantly increased in CKD and post-kidney transplant CKD. Plasma Ba levels correlated significantly with lower brachial artery flow-mediated dilation, lower Chronic Kidney Disease Epidemiology Collaboration glomerular filtration rate, and higher urinary albumin/creatinine ratio. Factor D levels were significantly higher in the plasma microparticles of patients with CKD versus healthy controls. Plasma microparticles isolated from patients with CKD and containing factor D activated the alternative pathway in vitro. CONCLUSION: The alternative complement pathway is activated in CKD and correlates with endothelial dysfunction and markers of CKD. Future studies are needed to evaluate whether endothelial microparticles with increased factor D play a pathologic role in CKD-associated vascular disease. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02230202.


Assuntos
Micropartículas Derivadas de Células/metabolismo , Fator B do Complemento/metabolismo , Fator D do Complemento/metabolismo , Via Alternativa do Complemento , Endotélio Vascular/fisiopatologia , Insuficiência Renal Crônica/metabolismo , Adulto , Idoso , Artéria Braquial/diagnóstico por imagem , Artéria Braquial/fisiopatologia , Estudos de Casos e Controles , Ativação do Complemento , Complemento C4a/metabolismo , Complemento C5a/metabolismo , Complexo de Ataque à Membrana do Sistema Complemento/metabolismo , Proteínas do Sistema Complemento/metabolismo , Células Endoteliais , Feminino , Taxa de Filtração Glomerular , Humanos , Transplante de Rim , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Proteômica , Insuficiência Renal Crônica/fisiopatologia , Insuficiência Renal Crônica/cirurgia , Índice de Gravidade de Doença , Vasodilatação
18.
Mol Biol Rep ; 45(5): 851-864, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29981048

RESUMO

The complement system plays an important role in inflammation and immunity. In this system, a potent inflammatory ligand is C5a, which initiates its effects by activating its core receptor C5aR1. Thus, compounds that interfere with the C5a-C5aR1 interaction could alleviate some inflammatory conditions. Consequently, several ligands that bind to either C5a or C5aR1 have previously been isolated and evaluated. In the present study, two RNA aptamers, aptamer 1 and aptamer 9, that specifically bind to hC5aR1 with much higher affinity than antibodies were isolated. These two aptamers were tested for their ability to interfere with the cognate ligand of hC5aR1, C5a, using a chemotaxis assay. Both aptamer 1 and 9 interfered with the C5a interaction, suggesting that the aptamers recognized the extracellular domain of hC5aR1 responsible for hC5a ligand binding. Considering the higher affinity of aptamers to the hC5aR1 and their interference with hC5a ligand binding, further study is warranted to explore not only their applications in the diagnosis of inflammatory diseases but also their usefulness in modulating hC5a and hC5aR1 interactions.


Assuntos
Aptâmeros de Nucleotídeos/farmacologia , Complemento C5a/metabolismo , Receptor da Anafilatoxina C5a/química , Receptor da Anafilatoxina C5a/metabolismo , Animais , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/isolamento & purificação , Sítios de Ligação , Células CHO , Quimiotaxia , Cricetulus , Humanos , Ligantes , Ligação Proteica/efeitos dos fármacos , Domínios Proteicos
19.
Kidney Int ; 94(4): 689-700, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29884545

RESUMO

Certain kidney diseases are associated with complement activation although a renal triggering factor has not been identified. Here we demonstrated that renin, a kidney-specific enzyme, cleaves C3 into C3b and C3a, in a manner identical to the C3 convertase. Cleavage was specifically blocked by the renin inhibitor aliskiren. Renin-mediated C3 cleavage and its inhibition by aliskiren also occurred in serum. Generation of C3 cleavage products was demonstrated by immunoblotting, detecting the cleavage product C3b, by N-terminal sequencing of the cleavage product, and by ELISA for C3a release. Functional assays showed mast cell chemotaxis towards the cleavage product C3a and release of factor Ba when the cleavage product C3b was combined with factor B and factor D. The renin-mediated C3 cleavage product bound to factor B. In the presence of aliskiren this did not occur, and less C3 deposited on renin-producing cells. The effect of aliskiren was studied in three patients with dense deposit disease and this demonstrated decreased systemic and renal complement activation (increased C3, decreased C3a and C5a, decreased renal C3 and C5b-9 deposition and/or decreased glomerular basement membrane thickness) over a follow-up period of four to seven years. Thus, renin can trigger complement activation, an effect inhibited by aliskiren. Since renin concentrations are higher in renal tissue than systemically, this may explain the renal propensity of complement-mediated disease in the presence of complement mutations or auto-antibodies.


Assuntos
Amidas/farmacologia , Ativação do Complemento/efeitos dos fármacos , Complemento C3/química , Fumaratos/farmacologia , Glomerulonefrite Membranoproliferativa/metabolismo , Glomerulonefrite Membranoproliferativa/terapia , Renina/química , Amidas/uso terapêutico , Quimiotaxia/efeitos dos fármacos , Criança , Complemento C3/metabolismo , Complemento C3a/química , Complemento C3a/metabolismo , Complemento C3b/química , Complemento C3b/metabolismo , Complemento C4/química , Complemento C5a/química , Complemento C5a/metabolismo , Complemento C5b/química , Complemento C5b/metabolismo , Fator B do Complemento/química , Fator D do Complemento/química , Feminino , Fumaratos/uso terapêutico , Membrana Basal Glomerular/patologia , Glomerulonefrite Membranoproliferativa/patologia , Humanos , Mastócitos/fisiologia , Renina/antagonistas & inibidores , Renina/metabolismo
20.
Mol Immunol ; 102: 32-41, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29914696

RESUMO

Polymicrobial sepsis (after cecal ligation and puncture, CLP) causes robust complement activation with release of C5a. Many adverse events develop thereafter and will be discussed in this review article. Activation of complement system results in generation of C5a which interacts with its receptors (C5aR1, C5aR2). This leads to a series of harmful events, some of which are connected to the cardiomyopathy of sepsis, resulting in defective action potentials in cardiomyocytes (CMs), activation of the NLRP3 inflammasome in CMs and the appearance of extracellular histones, likely arising from activated neutrophils which form neutrophil extracellular traps (NETs). These events are associated with activation of mitogen-activated protein kinases (MAPKs) in CMs. The ensuing release of histones results in defective action potentials in CMs and reduced levels of [Ca2+]i-regulatory enzymes including sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2) and Na+/Ca2+ exchanger (NCX) as well as Na+/K+-ATPase in CMs. There is also evidence that CLP causes release of IL-1ß via activation of the NLRP3 inflammasome in CMs of septic hearts or in CMs incubated in vitro with C5a. Many of these events occur after in vivo or in vitro contact of CMs with histones. Together, these data emphasize the role of complement (C5a) and C5a receptors (C5aR1, C5aR2), as well as extracellular histones in events that lead to cardiac dysfunction of sepsis (septic cardiomyopathy).


Assuntos
Cardiomiopatias/sangue , Cardiomiopatias/etiologia , Complemento C5a/metabolismo , Histonas/metabolismo , Sepse/complicações , Animais , Cardiomiopatias/fisiopatologia , Ativação do Complemento/fisiologia , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA