RESUMO
The chemokine Cxcl1 plays a crucial role in recruiting neutrophils in response to infection. The early events in chemokine-mediated neutrophil extravasation involve a sequence of highly orchestrated steps including rolling, adhesion, arrest, and diapedesis. Cxcl1 function is determined by its properties of reversible monomer-dimer equilibrium and binding to Cxcr2 and glycosaminoglycans. Here, we characterized how these properties orchestrate extravasation using intravital microscopy of the cremaster. Compared to WT Cxcl1, which exists as both a monomer and a dimer, the trapped dimer caused faster rolling, less adhesion, and less extravasation. Whole-mount immunofluorescence of the cremaster and arrest assays confirmed these data. Moreover, the Cxcl1 dimer showed impaired LFA-1-mediated neutrophil arrest that could be attributed to impaired Cxcr2-mediated ERK signaling. We conclude that Cxcl1 monomer-dimer equilibrium and potent Cxcr2 activity of the monomer together coordinate the early events in neutrophil recruitment.
Assuntos
Glicosaminoglicanos , Neutrófilos , Quimiocina CXCL1/metabolismo , Neutrófilos/metabolismo , Movimento Celular , Glicosaminoglicanos/metabolismo , Quimiocinas/metabolismo , Infiltração de Neutrófilos , Receptores de Interleucina-8B/metabolismoRESUMO
Neutrophils infiltrate several types of cancer; however, whether their presence is associated with disease progression remains controversial. Here, we show that colon tumors overexpress neutrophil chemoattractants compared to healthy tissues, leading to their recruitment to the invasive margin and the central part of colon tumors. Of note, tumor-associated neutrophils expressing tumor necrosis factor α, which usually represents an antitumoral phenotype, were predominantly located in the invasive margin. Tumor-associated neutrophils from the invasive margin displayed an antitumoral phenotype with higher ICAM-1 and CD95 expression than neutrophils from healthy adjacent tissues. A higher neutrophil/lymphocyte ratio was found at later stages compared to the early phases of colon cancer. A neutrophil/lymphocyte ratio ≤3.5 predicted tumor samples had significantly more neutrophils at the invasive margin and the central part. Moreover, tumor-associated neutrophils at the invasive margin of early-stage tumors showed higher ICAM-1 and CD95 expression. Coculture of colon cancer cell lines with primary neutrophils induced ICAM-1 and CD95 expression, confirming our in situ findings. Thus, our data demonstrate that tumor-associated neutrophils with an antitumoral phenotype characterized by high ICAM-1 and CD95 expression infiltrate the invasive margin of early-stage colon tumors, suggesting that these cells can combat the disease at its early courses. The presence of tumor-associated neutrophils with antitumoral phenotype could help predict outcomes of patients with colon cancer.
Assuntos
Neoplasias do Colo , Neutrófilos , Humanos , Neutrófilos/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , Neoplasias do Colo/patologia , FenótipoRESUMO
Cervical cancer is a public health problem diagnosed in advanced stages, and its main risk factor is persistent high-risk human papillomavirus infection. Today, it is necessary to study new treatment strategies, such as immunotherapy, that use different targets of the tumor microenvironment. In this study, the K14E7E2 mouse was used as a cervical cancer model to evaluate the inhibition of indolamine-2,3-dioxygenase 1 (IDO-1) and C-X-C chemokine receptor type 2 (CXCR-2) as potential anti-tumor targets. DL-1MT and SB225002 were administered for 30 days in two regimens (R1 and R2) based on combination and single therapy approaches to inhibit IDO-1 and CXCR-2, respectively. Subsequently, the reproductive tracts were resected and analyzed to determine the tumor areas, and IHCs were performed to assess proliferation, apoptosis, and CD8 cellular infiltration. Our results revealed that combined inhibition of IDO-1 and CXCR-2 significantly reduces the areas of cervical tumors (from 196.0 mm2 to 58.24 mm2 in R1 and 149.6 mm2 to 52.65 mm2 in R2), accompanied by regions of moderate dysplasia, decreased papillae, and reduced inflammation. Furthermore, the proliferation diminished, and apoptosis and intra-tumoral CD8 T cells increased. In conclusion, the combined inhibition of IDO-1 and CXCR-2 is helpful in the antitumor response against preclinical cervical cancer.
RESUMO
Helicobacter pylori and EBV are considered the main risk factors in developing gastric cancer. Both pathogens establish life-lasting infections and both are considered carcinogenic in humans. Different lines of evidence support that both pathogens cooperate to damage the gastric mucosa. Helicobacter pylori CagA positive virulent strains induce the gastric epithelial cells to secrete IL-8, which is a potent chemoattractant for neutrophils and one of the most important chemokines for the bacterium-induced chronic gastric inflammation. EBV is a lymphotropic virus that persists in memory B cells. The mechanism by which EBV reaches, infects and persists in the gastric epithelium is not presently understood. In this study, we assessed whether Helicobacter pylori infection would facilitate the chemoattraction of EBV-infected B lymphocytes. We identified IL-8 as a powerful chemoattractant for EBV-infected B lymphocytes, and CXCR2 as the main IL-8 receptor whose expression is induced by the EBV in infected B lymphocytes. The inhibition of expression and/or function of IL-8 and CXCR2 reduced the ERK1/2 and p38 MAPK signaling and the chemoattraction of EBV-infected B lymphocytes. We propose that IL-8 at least partially explains the arrival of EBV-infected B lymphocytes to the gastric mucosa, and that this illustrates a mechanism of interaction between Helicobacter pylori and EBV.
Assuntos
Linfócitos B , Fatores Quimiotáticos , Infecções por Vírus Epstein-Barr , Infecções por Helicobacter , Interleucina-8 , Humanos , Antígenos de Bactérias , Linfócitos B/metabolismo , Linfócitos B/virologia , Proteínas de Bactérias/metabolismo , Fatores Quimiotáticos/metabolismo , Células Epiteliais , Mucosa Gástrica/metabolismo , Herpesvirus Humano 4/metabolismo , Interleucina-8/metabolismo , Neoplasias GástricasRESUMO
OBJECTIVE: This study aimed to investigate the effects of FK506 on experimental sepsis immunopathology. It investigated the effect of FK506 on leukocyte recruitment to the site of infection, systemic cytokine production, and organ injury in mice with sepsis. METHODS: Using a murine cecal ligation and puncture (CLP) peritonitis model, the experiments were performed with wild-type (WT) mice and mice deficient in the gene Nfat1 (Nfat1-/-) in the C57BL/6 background. Animals were treated with 2.0 mg/kg of FK506, subcutaneously, 1 h before the sepsis model, twice a day (12 h/12 h). The number of bacteria colony forming units (CFU) was manually counted. The number of neutrophils in the lungs was estimated by the myeloperoxidase (MPO) assay. The expression of CXCR2 in neutrophils was determined using flow cytometry analysis. The expression of inflammatory cytokines in macrophage was determined using ELISA. The direct effect of FK506 on CXCR2 internalization was evaluated using HEK-293T cells after CXCL2 stimulation by the BRET method. RESULTS: FK506 treatment potentiated the failure of neutrophil migration into the peritoneal cavity, resulting in bacteremia and an exacerbated systemic inflammatory response, which led to higher organ damage and mortality rates. Failed neutrophil migration was associated with elevated CXCL2 chemokine plasma levels and lower expression of the CXCR2 receptor on circulating neutrophils compared with non-treated CLP-induced septic mice. FK506 did not directly affect CXCL2-induced CXCR2 internalization by transfected HEK-293 cells or mice neutrophils, despite increasing CXCL2 release by LPS-treated macrophages. Finally, the CLP-induced response of Nfat1-/- mice was similar to those observed in the Nfat1+/+ genotype, suggesting that the FK506 effect is not dependent on the NFAT1 pathway. CONCLUSION: Our data indicate that the increased susceptibility to infection of FK506-treated mice is associated with failed neutrophil migration due to the reduced membrane availability of CXCR2 receptors in response to exacerbated levels of circulating CXCL2.
Assuntos
Neutrófilos , Sepse , Humanos , Camundongos , Animais , Tacrolimo/farmacologia , Tacrolimo/uso terapêutico , Células HEK293 , Camundongos Endogâmicos C57BL , Sepse/metabolismo , Infiltração de NeutrófilosRESUMO
cDNA microarray data conducted by our group revealed overexpression of CXCL2 and CXCL8 in ovarian cancer (OC) microenvironment. Herein, we have proven that the chemokine receptor, CXCR2, is a pivotal molecule in re-sensitizing OC to cisplatin, and its inhibition decreases cell proliferation, viability, tumor size in cisplatin-resistant cells, as well as reversed the overexpression of mesenchymal epithelium transition markers. Altogether, our study indicates a central effect of CXCR2 in preventing tumor progression, due to acquisition of cisplatin chemoresistant phenotype by tumor cells, and patients' high lethality rate. We found that the overexpression of CXCR2 by OC cells is persistent and anomalously confined to the cellular nuclei, thus pointing to an urge in developing highly lipophilic molecules that promptly permeate cells, bind to and inhibit nuclear CXCR2 to fight OC, instead of relying on the high-cost genetic engineered cells.
Assuntos
Cisplatino/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológico , Receptores de Interleucina-8B/antagonistas & inibidores , Animais , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quimiocina CXCL2/metabolismo , Embrião de Galinha , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Invasividade Neoplásica , Proteínas de Neoplasias/metabolismo , Neovascularização Patológica/tratamento farmacológico , Neoplasias Ovarianas/irrigação sanguínea , Neoplasias Ovarianas/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores de Interleucina-8B/metabolismo , Análise de Sobrevida , Serina-Treonina Quinases TOR/metabolismoRESUMO
ABSTRACT Purpose To investigate the relationship between atherosclerotic abdominal aortic aneurysm (AAA) and CXC chemokine receptor type 2 (CXCR2). Methods Mouse AAA model was established by embedding angiotensin-II pump (1000 ng/kg/min) in ApoE-/- mice. Mice were received SB225002, a selective CXCR2 antagonist, for treatment. Blood pressure was recorded, and CXCR2+ macrophages were examined by flow cytometry analysis. Terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) staining was performed to detect cell apoptosis of abdominal aortic aneurysms. Macrophages were isolated from ApoE-/- mice and treated with Ang II and/or SB225002. Dihydroethidium staining was carried out to determine reactive oxygen species (ROS) activity. Enzyme-linked immunosorbent assay (ELISA) was performed to determine the production of IL-1β and TNF-α. The corresponding gene expressions were measured using real-time polymerase chain reaction (PCR), western blot, and immunohistochemistry staining. Results We found that Ang II activated the expression of CXCR2 in monocytes during the formation of AAA. Inhibition of CXCR2 significantly reduced the size of AAA, attenuated inflammation and phenotypic changes in blood vessels. Ang II-induced macrophages exhibited elevated ROS activity, and elevated levels of 1β and TNF-α, which were then partly abolished by SB225002. Conclusions CXCR2 plays an important role in AAA, suggesting that inhibiting CXCR2 may be a new treatment for AAA.
Assuntos
Animais , Camundongos , Aneurisma da Aorta Abdominal/prevenção & controle , Aneurisma da Aorta Abdominal/tratamento farmacológico , Apolipoproteínas E/genética , Angiotensina II , Receptores de Interleucina-8B , Modelos Animais de Doenças , Macrófagos , Camundongos Endogâmicos C57BLRESUMO
Purpose To investigate the relationship between atherosclerotic abdominal aortic aneurysm (AAA) and CXC chemokine receptor type 2 (CXCR2). Methods Mouse AAA model was established by embedding angiotensin-II pump (1000 ng/kg/min) in ApoE-/- mice. Mice were received SB225002, a selective CXCR2 antagonist, for treatment. Blood pressure was recorded, and CXCR2+ macrophages were examined by flow cytometry analysis. Terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) staining was performed to detect cell apoptosis of abdominal aortic aneurysms. Macrophages were isolated from ApoE-/- mice and treated with Ang II and/or SB225002. Dihydroethidium staining was carried out to determine reactive oxygen species (ROS) activity. Enzyme-linked immunosorbent assay (ELISA) was performed to determine the production of IL-1 and TNF-. The corresponding gene expressions were measured using real-time polymerase chain reaction (PCR), western blot, and immunohistochemistry staining. Results We found that Ang II activated the expression of CXCR2 in monocytes during the formation of AAA. Inhibition of CXCR2 significantly reduced the size of AAA, attenuated inflammation and phenotypic changes in blood vessels. Ang II-induced macrophages exhibited elevated ROS activity, and elevated levels of 1 and TNF-, which were then partly abolished by SB225002. Conclusions CXCR2 plays an important role in AAA, suggesting that inhibiting CXCR2 may be a new treatment for AAA.(AU)
Assuntos
Animais , Camundongos , Receptores de Interleucina-8B/administração & dosagem , Aneurisma da Aorta Abdominal/veterinária , Aneurisma da Aorta Abdominal/terapia , Angiotensina IIRESUMO
PURPOSE: The aim was to investigate the systemic levels of cytokines and the expression of the chemokine receptor CXCR2 in circulating neutrophils in patients with non-neoplastic ovarian lesions, benign neoplasia or malignant neoplasia. MATERIALS AND METHODS: Controls and patients with ovarian tumours were pre-operatively compared for the production of cytokines (IL-2, IL-5, IL-6, IL-8, IL-10 and TNF-α) by ELISA, and for the expression of the chemokine receptor, CXCR2, in neutrophils, by flow cytometry. Randomly selected patients within the malignant group were re-evaluated for the inflammatory parameters at 30 days after surgery. RESULTS: The serum concentrations of IL-6, IL-8 and IL-10 were significantly higher in the benign and malignant neoplasia than in the control group, and their levels were significantly higher in ovarian cancer patients than in patients with non-neoplastic tumours or benign neoplasia. Treatment reduced IL-8 serum levels but did not affect CXCR2 expression in neutrophils. Cut-off values for IL-6, IL-8, and IL-10 comparing malignant vs. benign neoplasia were 11.3, 71.7, 14.8, and comparing malignant neoplasm vs. non-neoplastic lesions were 7.2, 43.5, 12.3, respectively. CONCLUSIONS: Serum IL-6, IL-8, and IL-10 levels, and expression of CXCR2 in circulating neutrophils seem promising for distinguishing ovarian cancer patients from patients with benign tumours.
Assuntos
Biomarcadores Tumorais/sangue , Citocinas/sangue , Neoplasias Ovarianas/sangue , Receptores de Interleucina-8B/sangue , Adulto , Idoso , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Interleucina-10/sangue , Interleucina-2/sangue , Interleucina-5/sangue , Interleucina-6/sangue , Interleucina-8/sangue , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/patologia , Neoplasias Ovarianas/patologia , Fator de Necrose Tumoral alfa/sangueRESUMO
Neuropathic pain is a chronic pain characterized by injury to the central or peripheral nervous system and that most often causes disability in individuals. Among the mechanisms involved in central sensitization during neuropathic pain are cytokines and chemokines released by spinal glial cells; however, these mechanisms are not well elucidated. Thus, the present study aimed to investigate the involvement of Chemokine (C-X-C motif) ligand 1 (CXCL1) and glial cells in this process. Male Wistar rats weighing 220-240 g were used and underwent a neuropathic pain model induced by chronic constriction injury (CCI). To investigate the involvement of CXCL1, chemokine receptor type 2 (CXCR2), mitogen-activated protein kinases (MAPK) p38, and microglia and astrocytes, the following drugs were used: SB225002, an CXCR2 antagonist; SML0543, a MAPK p38 inhibitor; minocycline, a microglia inhibitor; fluorocitrate, an astrocytes inhibitor; and recombinant CXCL1. The microglia, astrocytes, CXCL1, and MAPK p38 protein levels was evaluated by a Western blot assay. Furthermore, an immunofluorescence assay was performed to localize microglia and astrocytes immunoreactivity in the spinal cord. The results demonstrated that both CCI and CXCL1 induced nociception, and this effect was reversed by SB225002. In addition, minocycline, fluorocitrate, and SML0543 reversed the mechanical allodynia induced by CCI. Furthermore, there was an increase of spinal CXCL1 and microglial marker Iba1 protein levels , which was reversed by SB225002. This antagonist also reduced the Iba1 immunoreactivity in spinal cord. Thus, the present study suggests that the CXCL1 chemokine participates in neuropathic pain through CXCR2 activation in spinal microglia.