Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.206
Filtrar
1.
PLoS One ; 15(8): e0237746, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32810144

RESUMO

In recent years, several studies suggested that the ability of hyperbaric oxygen therapy (HBOT) to promote healing in patients with diabetic ulcers and chronic wounds is due to the reduction of inflammatory cytokines and to a significant decrease in neutrophils recruitment to the damaged area. α4 and ß2 integrins are receptors mediating the neutrophil adhesion to the endothelium and the comprehension of the effects of hyperbaric oxygenation on their expression and functions in neutrophils could be of great importance for the design of novel therapeutic protocols focused on anti-inflammatory agents. In this study, the α4 and ß2 integrins' expression and functions have been evaluated in human primary neutrophils obtained from patients with chronic non-healing wounds and undergoing a prolonged HBOT (150 kPa per 90 minutes). The effect of a peptidomimetic α4ß1 integrin antagonist has been also analyzed under these conditions. A statistically significant decrease (68%) in ß2 integrin expression on neutrophils was observed during the treatment with HBO and maintained one month after the last treatment, while α4 integrin levels remained unchanged. However, cell adhesion function of both neutrophilic integrins α4ß1 and ß2 was significantly reduced 70 and 67%, respectively), but α4ß1 integrin was still sensitive to antagonist inhibition in the presence of fibronectin, suggesting that a combined therapy between HBOT and integrin antagonists could have greater antinflammatory efficacy.


Assuntos
Oxigenação Hiperbárica , Integrina alfa4beta1/antagonistas & inibidores , Neutrófilos/imunologia , Peptidomiméticos/uso terapêutico , Úlcera Cutânea/terapia , Idoso , Idoso de 80 Anos ou mais , Antígenos CD18/análise , Antígenos CD18/metabolismo , Adesão Celular/imunologia , Doença Crônica/terapia , Terapia Combinada/métodos , Feminino , Seguimentos , Humanos , Integrina alfa4beta1/análise , Integrina alfa4beta1/metabolismo , Masculino , Pessoa de Meia-Idade , Infiltração de Neutrófilos , Neutrófilos/metabolismo , Peptidomiméticos/farmacologia , Cultura Primária de Células , Úlcera Cutânea/sangue , Úlcera Cutânea/imunologia , Úlcera Cutânea/patologia , Resultado do Tratamento , Cicatrização/efeitos dos fármacos , Cicatrização/imunologia
2.
Proc Natl Acad Sci U S A ; 117(36): 22367-22377, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32848068

RESUMO

The γδ T cells reside predominantly at barrier sites and play essential roles in immune protection against infection and cancer. Despite recent advances in the development of γδ T cell immunotherapy, our understanding of the basic biology of these cells, including how their numbers are regulated in vivo, remains poor. This is particularly true for tissue-resident γδ T cells. We have identified the ß2 family of integrins as regulators of γδ T cells. ß2-integrin-deficient mice displayed a striking increase in numbers of IL-17-producing Vγ6Vδ1+ γδ T cells in the lungs, uterus, and circulation. Thymic development of this population was normal. However, single-cell RNA sequencing revealed the enrichment of genes associated with T cell survival and proliferation specifically in ß2-integrin-deficient IL-17+ cells compared to their wild-type counterparts. Indeed, ß2-integrin-deficient Vγ6+ cells from the lungs showed reduced apoptosis ex vivo, suggesting that increased survival contributes to the accumulation of these cells in ß2-integrin-deficient tissues. Furthermore, our data revealed an unexpected role for ß2 integrins in promoting the thymic development of the IFNγ-producing CD27+ Vγ4+ γδ T cell subset. Together, our data reveal that ß2 integrins are important regulators of γδ T cell homeostasis, inhibiting the survival of IL-17-producing Vγ6Vδ1+ cells and promoting the thymic development of the IFNγ-producing Vγ4+ subset. Our study introduces unprecedented mechanisms of control for γδ T cell subsets.


Assuntos
Antígenos CD18 , Linfócitos Intraepiteliais , Timo , Animais , Antígenos CD18/genética , Antígenos CD18/imunologia , Antígenos CD18/metabolismo , Homeostase/imunologia , Interleucina-17/genética , Interleucina-17/imunologia , Interleucina-17/metabolismo , Linfócitos Intraepiteliais/imunologia , Linfócitos Intraepiteliais/metabolismo , Linfócitos Intraepiteliais/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Timo/crescimento & desenvolvimento , Timo/imunologia , Timo/metabolismo
3.
Nat Commun ; 11(1): 3172, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32576838

RESUMO

Bone marrow engraftment of the hematopoietic stem and progenitor cells (HSPCs) involves homing to the vasculatures and lodgment to their niches. How HSPCs transmigrate from the vasculature to the niches is unclear. Here, we show that loss of diaphanous-related formin mDia2 leads to impaired engraftment of long-term hematopoietic stem cells and loss of competitive HSPC repopulation. These defects are likely due to the compromised trans-endothelial migration of HSPCs since their homing to the bone marrow vasculatures remained intact. Mechanistically, loss of mDia2 disrupts HSPC polarization and induced cytoplasmic accumulation of MAL, which deregulates the activity of serum response factor (SRF). We further reveal that beta2 integrins are transcriptional targets of SRF. Knockout of beta2 integrins in HSPCs phenocopies mDia2 deficient mice. Overexpression of SRF or beta2 integrins rescues HSPC engraftment defects associated with mDia2 deficiency. Our findings show that mDia2-SRF-beta2 integrin signaling is critical for HSPC lodgment to the niches.


Assuntos
Antígenos CD18/metabolismo , Forminas/metabolismo , Células-Tronco Hematopoéticas/fisiologia , Proteínas Associadas aos Microtúbulos/metabolismo , NADPH Desidrogenase/metabolismo , Animais , Medula Óssea/metabolismo , Modelos Animais de Doenças , Forminas/genética , Transplante de Células-Tronco Hematopoéticas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Associadas aos Microtúbulos/genética , NADPH Desidrogenase/genética , Transdução de Sinais
4.
Sci Rep ; 10(1): 2142, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32034208

RESUMO

Neutrophils are innate immune effector cells that traffic from the circulation to extravascular sites of inflammation. ß2 integrins are important mediators of the processes involved in neutrophil recruitment. Although neutrophils express the cytoskeletal protein vinculin, they do not form mature focal adhesions. Here, we characterize the role of vinculin in ß2 integrin-dependent neutrophil adhesion, migration, mechanosensing, and recruitment. We observe that knockout of vinculin attenuates, but does not completely abrogate, neutrophil adhesion, spreading, and crawling under static conditions. However, we also found that vinculin deficiency does not affect these behaviors in the presence of forces from fluid flow. In addition, we identify a role for vinculin in mechanosensing, as vinculin-deficient neutrophils exhibit attenuated spreading on stiff, but not soft, substrates. Consistent with these findings, we observe that in vivo neutrophil recruitment into the inflamed peritoneum of mice remains intact in the absence of vinculin. Together, these data suggest that while vinculin regulates some aspects of neutrophil adhesion and spreading, it may be dispensable for ß2 integrin-dependent neutrophil recruitment in vivo.


Assuntos
Adesão Celular , Infiltração de Neutrófilos , Neutrófilos/metabolismo , Vinculina/metabolismo , Animais , Antígenos CD18/metabolismo , Células Cultivadas , Mecanotransdução Celular , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/fisiologia
5.
Infect Immun ; 88(5)2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32041787

RESUMO

Phagocytosis is the key mechanism for host control of Pseudomonas aeruginosa, a motile Gram-negative, opportunistic bacterial pathogen which frequently undergoes adaptation and selection for traits that are advantageous for survival. One such clinically relevant adaptation is the loss of bacterial motility, observed within chronic infections, that is associated with increased antibiotic tolerance and phagocytic resistance. Previous studies using phagocytes from a leukocyte adhesion deficiency type 1 (LAD-I) patient identified CD18 as a putative cell surface receptor for uptake of live P. aeruginosa However, how bacterial motility alters direct engagement with CD18-containing integrins remains unknown. Here we demonstrate, with the use of motile and isogenic nonmotile deletion mutants of two independent strains of P. aeruginosa and with CRISPR-generated CD18-deficient cell lines in human monocytes and murine neutrophils, that CD18 expression facilitates the uptake of both motile and nonmotile P. aeruginosa However, unexpectedly, mechanistic studies revealed that CD18 expression was dispensable for the initial attachment of the bacteria to the host cells, which was validated with ectopic expression of complement receptor 3 (CR3) by CHO cells. Our data support that surface N-linked glycan chains (N-glycans) likely facilitate the initial interaction of bacteria with monocytes and cooperate with CD18 integrins in trans to promote internalization of bacteria. Moreover, talin-1 and kindlin-3 proteins promote uptake, but not binding, of P. aeruginosa by murine neutrophils, which supports a role for CD18 integrin signaling in this process. These findings provide novel insights into the cellular determinants for phagocytic recognition and uptake of P. aeruginosa.


Assuntos
Antígenos CD18/metabolismo , Integrinas/metabolismo , Fagócitos/metabolismo , Fagócitos/microbiologia , Pseudomonas aeruginosa/metabolismo , Pseudomonas aeruginosa/patogenicidade , Animais , Células CHO , Linhagem Celular , Cricetulus , Camundongos , Monócitos/metabolismo , Monócitos/microbiologia , Neutrófilos/metabolismo , Neutrófilos/microbiologia , Ligação Proteica/fisiologia , Infecções por Pseudomonas/metabolismo , Infecções por Pseudomonas/microbiologia , Talina/metabolismo , Células Th1
6.
J Leukoc Biol ; 107(2): 175-183, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31475386

RESUMO

ß2 integrins are the main adhesion molecules in neutrophils and other leukocytes and are rapidly activated by inside-out signaling, which results in conformational changes that are transmitted through the transmembrane domain (TMD). Here, we investigated the biologic effect of introducing a proline mutation in the ß2 integrin TMD to create a flexible kink that uncouples the topology of the inner half of the TMD from the outer half and impairs integrin activation. The ß2 integrin alpha chains, αL, αM, αX, and αD, all contain an inserted (I) domain with homology to von Willebrand factor A domain. ß2 activation was monitored in a homogenous binding assay of 2 reporter monoclonal antibodies: KIM127 reporting extension (E+ ) and mAb24 reporting the high-affinity (H+ ) conformation of the ß2 I-like domain. The proline mutation partially diminished chemokine-induced extension, but not the high-affinity conformation. The proline mutation in the TMD of ß2 completely inhibited arrest of rolling HL-60 cells in response to the chemokine IL-8. TMD mutant HL-60 cells rolling on P-selectin and ICAM-1 were unable to reduce their rolling velocity in response to IL-8. Quantitative dynamic footprinting live-cell imaging showed that blocking TMD topology transmission impaired the chemokine-induced activation of ß2, limiting the appearance of extended high-affinity (E+ H+ ) ß2. This also resulted in a defect in early spreading (3 min after arrest), which could be overcome by forced integrin activation using Mn2+ . We conclude that the TMD proline mutation severely impairs ß2 integrin extension, cell arrest, and early spreading.


Assuntos
Antígenos CD18/metabolismo , Pontos de Checagem do Ciclo Celular , Migração e Rolagem de Leucócitos/fisiologia , Prolina/metabolismo , Antígenos CD18/química , Antígenos CD18/genética , Células HL-60 , Humanos , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/metabolismo , Interleucina-8/farmacologia , Migração e Rolagem de Leucócitos/efeitos dos fármacos , Mutação , Selectina-P/genética , Selectina-P/metabolismo , Prolina/química , Prolina/genética , Conformação Proteica , Domínios Proteicos
7.
J Leukoc Biol ; 107(1): 69-83, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31478251

RESUMO

Aspergillus fumigatus (A. fumigatus) is an environmental fungus and a human pathogen. Neutrophils are critical effector cells during the fungal infections, and neutropenia is a risk factor for the development of pulmonary aspergillosis. Neutrophil extracellular traps (NETs) are released by neutrophils in response to A. fumigatus and inhibit the conidial germination. In this work, we observed that the receptors TLR2, TLR4, and Dectin-1 were dispensable for the A. fumigatus induced NET release. In contrast CD11b/CD18 was critical for the NET release in response to A. fumigatus conidia, and this required the CD11b I-domain-mediated recognition, whereas the blockade of the CD11b lectin domain did not affect the A. fumigatus induced NET release. A. fumigatus induced NET release relied on the activity of spleen tyrosine kinase (Syk), Src family kinase(s), and class IA PI3 kinase δ. Although A. fumigatus promoted histone citrullination, this process was dispensable for the NET release in response to A. fumigatus conidia. The A. fumigatus induced NET release required the reactive oxygen species generation by the NOX2 complex, in a downstream pathway requiring CD11b/CD18, Src kinase family activity, Syk and PI3K class IA δ. Our findings thus reveal the signaling pathways involved in the formation of NETs in response to A. fumigatus.


Assuntos
Aspergilose/imunologia , Aspergillus fumigatus/imunologia , DNA/imunologia , Armadilhas Extracelulares/imunologia , Histonas/química , Antígeno de Macrófago 1/metabolismo , Neutrófilos/imunologia , Proteína-Arginina Desiminase do Tipo 4/química , Aspergilose/metabolismo , Aspergilose/microbiologia , Aspergillus fumigatus/metabolismo , Antígeno CD11b/metabolismo , Antígenos CD18/metabolismo , Citrulinação , DNA/metabolismo , Armadilhas Extracelulares/microbiologia , Humanos , Antígeno de Macrófago 1/genética , Neutrófilos/microbiologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteína-Arginina Desiminase do Tipo 4/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Quinase Syk/metabolismo , Quinases da Família src/metabolismo
8.
Cell Mol Biol Lett ; 24: 63, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827539

RESUMO

Background: The participation of long noncoding RNAs (lncRNAs) in myocardial infarction has recently been noted. However, their underlying roles in the border zone of myocardial infarction remain unclear. This study uses microarrays to determine the profiles of lncRNAs and mRNAs in the border zone. Methods: Bioinformatics methods were employed to uncover their underlying roles. Highly dysregulated lncRNAs was further validated via PCR. Results: Four hundred seven lncRNAs and 752 mRNAs were upregulated, while 132 lncRNAs and 547 mRNAs were downregulated in the border zone of myocardial infarction. A circos graph was constructed to visualize the chromosomal distribution and classification of the dysregulated lncRNAs and mRNAs. The upregulated mRNAs in the border zone were most highly enriched in cytokine activity, binding, cytokine receptor binding and related processes, as ascertained through Go analysis. Pathway analysis of the upregulated mRNAs showed the most significant changes were in the TNF signaling pathway, cytokine-cytokine receptor interaction and chemokine signaling pathway and similar pathways and interactions. An lncRNA-mRNA co-expression network was established to probe into the underlying functions of the 10 most highly dysregulated lncRNAs based on their co-expressed mRNAs. In the co-expression network, we found 16 genes directly involved in myocardial infarction, including Alox5ap, Itgb2 and B4galt1. The lncRNAs AY212271, EF424788 and MRAK088538, among others, might be associated with myocardial infarction. BC166504 is probably a key lncRNA in the border zone of myocardial infarction. Conclusions: The results may have revealed some aberrantly expressed lncRNAs and mRNAs that contribute to the underlying pathophysiological mechanisms of myocardial infarction.


Assuntos
Regulação da Expressão Gênica , Redes Reguladoras de Genes , Infarto do Miocárdio/genética , RNA Longo não Codificante/genética , RNA Mensageiro/genética , Proteínas Ativadoras de 5-Lipoxigenase/genética , Proteínas Ativadoras de 5-Lipoxigenase/metabolismo , Animais , Aorta Torácica/cirurgia , Antígenos CD18/genética , Antígenos CD18/metabolismo , Biologia Computacional/métodos , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Galactosiltransferases/genética , Galactosiltransferases/metabolismo , Perfilação da Expressão Gênica , Ontologia Genética , Ligadura , Masculino , Anotação de Sequência Molecular , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/fisiopatologia , Análise de Sequência com Séries de Oligonucleotídeos , RNA Longo não Codificante/classificação , RNA Longo não Codificante/metabolismo , RNA Mensageiro/classificação , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Receptores de Citocinas/genética , Receptores de Citocinas/metabolismo , Transdução de Sinais
9.
FASEB J ; 33(11): 12972-12982, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31500447

RESUMO

Prenatal nicotine exposure (PNE) induces developmental toxicity in offspring. However, the long-term harmful effects on bone development and the intrauterine programming mechanism attributed to PNE remain unclear. In the present research, pregnant Wistar rats were injected subcutaneously with nicotine (2 mg/kg/d) to obtain and analyze bone samples from the fetal and adult offspring. Bone marrow mesenchymal stem cells (BMSCs) were treated with nicotine during osteogenic differentiation to clarify the related molecular mechanisms. The results indicated that PNE led to bone dysplasia in the fetuses and reduced bone mass in the adult offspring, which was mediated by the sustained activation of the local bone renin angiotensin system (RAS) and suppressed osteogenic differentiation before and after birth. In vitro, nicotine suppressed BMSCs' osteogenic function through promoting angiotensin-converting enzyme (ACE) expression and activating RAS. Furthermore, nicotine induced histone acetylase p300 into the nuclei of the BMSCs by acting on the α4ß2-nicotinic acetylcholine receptor (α4ß2-nAChR), leading to the increased histone 3 lysine 9 acetylation level of ACE and RAS activation. Taken together, the sustained activation of local bone RAS mediated prenatal nicotine-induced osteopenia in adult offspring via the α4ß2-nAChR-p300-ACE pathway.-Xiao, H., Wen, Y., Pan, Z., Shangguan, Y., Magdalou, J., Wang, H., Chen, L. Nicotine exposure during pregnancy programs osteopenia in male offspring rats via α4ß2-nAChR-p300-ACE pathway.


Assuntos
Doenças Ósseas Metabólicas/induzido quimicamente , Antígenos CD18/metabolismo , Integrina alfa4/metabolismo , Exposição Materna , Nicotina/administração & dosagem , Peptidil Dipeptidase A/metabolismo , Receptores Nicotínicos/metabolismo , Animais , Feminino , Masculino , Gravidez , Ratos , Ratos Wistar
10.
Gene ; 715: 144027, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31374327

RESUMO

OBJECTIVES: To explore the clinical and molecular characteristics of a Chinese Zhuang minority patient with leukocyte adhesion deficiency type-1 (LAD-1) and glucose-6-phosphate dehydrogenase deficiency (G6PDD). METHODS: Routine clinical and physical examinations were performed, and patient data was collected and analyzed. Protein expression levels of Itgb2 and glucose-6-phosphate dehydrogenase (G6pd) proteins were assessed by flow cytometry and the glucose-6-phosphate (G6P) substrate method, respectively. Whole exome sequencing was performed to investigate genetic variations of the patient and his parents. RESULTS: The patient had fester disease and delayed separation of the umbilical cord at birth. Staphylococcus was detected in the fluid secretion of the auditory meatus of the patient. He exhibited a recurrent cheek scab, swollen hand, and swollen gum. Hematological examination indicated dramatic elevation of leukocytes including lymphocytes, monocytes, neutrophils and eosinophils. A novel homozygous mutation was detected in the ITGB2 gene of the patient, which was determined to be a two nucleotide deletion at the site of c.1537-1538 (c.1537-1538delGT), causing a frameshift of 24 amino acids from p.513 and inducing a stop codon (p.V513Lfs*24). A base substitution mutation was identified at c.1466 (c.1466G>T) of G6PD on chromosome X of the patient, which resulted in an amino acid change from arginine to leucine at p.489 (p.R489L). The patient also showed deficient lymphocyte expression of CD18 (2.99%) and significant downregulation of the G6pd protein. CONCLUSIONS: The patient was diagnosed with G6PDD and moderate LAD-1. The combination of LAD-1 and G6PDD in this case may have been due to the high incidence of genetic disease in this minority ethnic population. Analyzing existing LAD-1 and G6PDD cases from different populations can facilitate disease diagnosis and treatment. Particularly, reporting pathogenic mutations of LAD-1 and G6PDD will be crucial for genetic testing and prenatal diagnosis in an effort to decrease the incidence of these diseases.


Assuntos
Antígenos CD18/genética , Deficiência de Glucosefosfato Desidrogenase/genética , Homozigoto , Síndrome da Aderência Leucocítica Deficitária/genética , Mutação de Sentido Incorreto , Substituição de Aminoácidos , Grupo com Ancestrais do Continente Asiático , Antígenos CD18/metabolismo , Deficiência de Glucosefosfato Desidrogenase/patologia , Humanos , Lactente , Síndrome da Aderência Leucocítica Deficitária/metabolismo , Síndrome da Aderência Leucocítica Deficitária/patologia , Leucócitos/metabolismo , Leucócitos/patologia , Masculino
11.
Elife ; 82019 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-31385804

RESUMO

Arrest of rapidly flowing neutrophils in venules relies on capturing through selectins and chemokine-induced integrin activation. Despite a long-established concept, we show here that gene inactivation of activating paired immunoglobulin-like receptor (PILR)-ß1 nearly halved the efficiency of neutrophil arrest in venules of the mouse cremaster muscle. We found that this receptor binds to CD99, an interaction which relies on flow-induced shear forces and boosts chemokine-induced ß2-integrin-activation, leading to neutrophil attachment to endothelium. Upon arrest, binding of PILR-ß1 to CD99 ceases, shifting the signaling balance towards inhibitory PILR-α. This enables integrin deactivation and supports cell migration. Thus, flow-driven shear forces guide sequential signaling of first activating PILR-ß1 followed by inhibitory PILR-α to prompt neutrophil arrest and then transmigration. This doubles the efficiency of selectin-chemokine driven neutrophil arrest by PILR-ß1 and then supports transition to migration by PILR-α.


Assuntos
Antígeno 12E7/metabolismo , Células Sanguíneas , Neutrófilos/fisiologia , Receptores Imunológicos/metabolismo , Migração Transendotelial e Transepitelial , Animais , Antígenos CD18/metabolismo , Camundongos , Ligação Proteica
12.
Front Immunol ; 10: 1138, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31191527

RESUMO

ß2-integrins are essential for immune system function because they mediate immune cell adhesion and signaling. Consequently, a loss of ß2-integrin expression or function causes the immunodeficiency disorders, Leukocyte Adhesion Deficiency (LAD) type I and III. LAD-III is caused by mutations in an important integrin regulator, kindlin-3, but exactly how kindlin-3 regulates leukocyte adhesion has remained incompletely understood. Here we demonstrate that mutation of the kindlin-3 binding site in the ß2-integrin (TTT/AAA-ß2-integrin knock-in mouse/KI) abolishes activation of the actin-regulated myocardin related transcription factor A/serum response factor (MRTF-A/SRF) signaling pathway in dendritic cells and MRTF-A/SRF-dependent gene expression. We show that Ras homolog gene family, member A (RhoA) activation and filamentous-actin (F-actin) polymerization is abolished in murine TTT/AAA-ß2-integrin KI dendritic cells, which leads to a failure of MRTF-A to localize to the cell nucleus to coactivate genes together with SRF. In addition, we show that dendritic cell gene expression, adhesion and integrin-mediated traction forces on ligand coated surfaces is dependent on the MRTF-A/SRF signaling pathway. The participation of ß2-integrin and kindlin-3-mediated cell adhesion in the regulation of the ubiquitous MRTF-A/SRF signaling pathway in immune cells may help explain the role of ß2-integrin and kindlin-3 in integrin-mediated gene regulation and immune system function.


Assuntos
Antígenos CD18/metabolismo , Células Dendríticas/metabolismo , Perfilação da Expressão Gênica/métodos , Fator de Resposta Sérica/metabolismo , Transativadores/metabolismo , Animais , Fenômenos Biomecânicos , Antígenos CD18/genética , Adesão Celular/genética , Movimento Celular/genética , Células Cultivadas , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Células Dendríticas/citologia , Ontologia Genética , Redes Reguladoras de Genes , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Fator de Resposta Sérica/genética , Transdução de Sinais/genética , Transativadores/genética , Proteína rhoA de Ligação ao GTP/genética , Proteína rhoA de Ligação ao GTP/metabolismo
13.
J Leukoc Biol ; 106(2): 431-446, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31075185

RESUMO

Cytoskeletal reorganization driven by Rho GTPases plays a crucial role in the migration of T cells, which are key regulators of immunity. The molecular mechanisms that control actin cytoskeleton remodeling during T cell movement have only partially been clarified as the function of many modulators has not been evaluated in these cells. Here, we report a new function of RhoGDI2 by showing that this protein positively regulates Rho GTPase activation during T cell adhesion and migration. RhoGDI2 knockdown significantly reduced T cell adhesion and migration. Furthermore, RhoGDI2 knockdown decreased the activation of Rac1 and Cdc42, 2 members of Rho GTPases, and the remodeling of the actin cytoskeleton. Upon P-selectin glycoprotein ligand-1 engagement, RhoGDI2 was phosphorylated at Y24 and Y153 by kinases related to ß2 integrin outside-in signaling, Src, c-Abl, and Syk, resulting in the accumulation of RhoGDI2 at the cell membrane. Subsequent phosphorylation of S31 induced the opening of RhoGDI2 and the release of Rho GTPases, whereas phosphorylation of Y153 might promote the activation of Rho GTPases by recruiting Vav1. Moreover, the disruption of lipid rafts with methyl-ß-cyclodextrin blocked the interaction between integrins and RhoGDI2, reducing the level of phosphorylated RhoGDI2 and the activation of downstream Rho GTPases. Based on these observations, RhoGDI2 is a target of intergrin outside-in signaling that activates Rho GTPases during T cell adhesion and migration, and RhoGDI2-mediated signal transduction is based on the lipid rafts integrity.


Assuntos
Antígenos CD18/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , Transdução de Sinais , Linfócitos T/imunologia , Linfócitos T/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Inibidor beta de Dissociação do Nucleotídeo Guanina rho/metabolismo , Adesão Celular/genética , Adesão Celular/imunologia , Quimiotaxia de Leucócito/genética , Quimiotaxia de Leucócito/imunologia , Humanos , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Glicoproteínas de Membrana/metabolismo , Microdomínios da Membrana/metabolismo , Fosforilação , Inibidor beta de Dissociação do Nucleotídeo Guanina rho/deficiência
14.
CNS Drugs ; 33(6): 605-614, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31093952

RESUMO

BACKGROUND: Targeted neutrophil inhibitory-hirulog (TNHH) is a novel hybrid glycoprotein that may be a potential drug candidate for acute ischaemic stroke. OBJECTIVE: The aim of this study was to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of TNHH in healthy volunteers and thereby determine the dose range for future clinical studies. METHODS: This randomized, placebo-controlled study was a single ascending dose design with dose levels of 0.05-1.8 mg/kg (n = 4-6 active, 2 placebos per cohort) in 68 participants. In the TNHH 0.2-1.8 mg/kg and control cohorts, pharmacokinetic and pharmacodynamic blood samples were collected over 168 h after intravenous (IV) administration. TNHH occupancy in peripheral blood neutrophils and blood coagulation were evaluated as the markers of target engagement. RESULTS: Two subjects withdrew from the trial before administration of the study treatment, 66 subjects are included in the data analysis. TNHH was well tolerated in all dose regimens. In total, five mild, self-limiting adverse events (AEs) were observed in 4 of the 66 study subjects. Dose-proportional increases in maximum plasma concentration (Cmax) and area under the curve (AUC0-t) of TNHH were observed. Traces of TNHH were excreted in urine. The elimination half-life (t½) ranged from 0.6 to 1.3 h in the eight groups with ascending dose levels. TNHH combined with CD11b/CD18 quickly achieved > 90% receptor occupancy in groups with doses above 0.2 mg/kg. The Cmax and AUC of binding TNHH with CD11b/CD18 increased with the dose. A significant prolongation with dose was observed on thrombin time (TT), and weak influences were observed on prothrombin time (PT) and activated partial thromboplastin time (APTT). CONCLUSION: TNHH was well-tolerated following IV infusion. The pharmacokinetic and pharmacodynamic characteristics of TNHH indicate that it merits clinical trials. It is recommended that the single dose of TNHH should be 1.0 mg/kg in future studies, and the expected effect may be achieved after 5-7 days of continuous administration. TRIAL REGISTRATION: The study is registered at http://www.chictr.org.cn as ChiCTR-TQR-14004752.


Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Fibrinolíticos , Glicoproteínas , Hirudinas , Neutrófilos/efeitos dos fármacos , Fragmentos de Peptídeos , Adolescente , Adulto , Área Sob a Curva , Coagulação Sanguínea/imunologia , Testes de Coagulação Sanguínea , Antígeno CD11b/metabolismo , Antígenos CD18/metabolismo , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Fibrinolíticos/efeitos adversos , Fibrinolíticos/farmacocinética , Fibrinolíticos/farmacologia , Glicoproteínas/farmacocinética , Glicoproteínas/farmacologia , Voluntários Saudáveis , Hirudinas/efeitos adversos , Hirudinas/farmacocinética , Hirudinas/farmacologia , Humanos , Infusões Intravenosas , Coeficiente Internacional Normatizado , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos/efeitos adversos , Fragmentos de Peptídeos/farmacocinética , Fragmentos de Peptídeos/farmacologia , Ligação Proteica , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/farmacocinética , Proteínas Recombinantes/farmacologia , Adulto Jovem
15.
Placenta ; 78: 23-28, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30955707

RESUMO

INTRODUCTION: Chronic histiocytic intervillositis of unknown etiology (CIUE) is a non-infectious, most probably immunologic placenta lesion. CIUE is associated with recurrent miscarriage, intrauterine growth restriction and stillbirth. Among the pathologic-anatomic defined placental lesions this entity displays the highest risk of recurrence in following pregnancies (about 67-100%). The histiocytic cells accumulate in the placental blood space but do not infiltrate into the villi or decidua. Sparsely known is the expression profile of these intervillous cells regarding histiocytic markers. METHODS: We analysed 5-22 markers by immunohistochemistry in a total of 41 placenta samples and evaluated decidual, villous and intervillous histiocytic cells. RESULTS: In CIUE, intervillous CD163+ histiocytes over-express CD11c/CD18 and down-regulate CD206/CD209, while CD163+ decidual and Hofbauer cells show low CD11c/CD18 and higher CD206/CD209 protein expressions. DISCUSSION: CD163 expression indicates a M2-like polarisation. CD11c and CD18 form the complement receptor 4 which could be related to a complement mediated trigger for aberrant cell accumulation in CIUE.


Assuntos
Antígeno CD11c/genética , Antígenos CD18/genética , Histiocitose/genética , Doenças Placentárias/genética , Placenta/metabolismo , Receptores de Complemento/genética , Adulto , Antígenos CD/genética , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/genética , Antígenos de Diferenciação Mielomonocítica/metabolismo , Antígeno CD11c/metabolismo , Antígenos CD18/metabolismo , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Vilosidades Coriônicas/imunologia , Vilosidades Coriônicas/metabolismo , Vilosidades Coriônicas/patologia , Doença Crônica , Feminino , Retardo do Crescimento Fetal/genética , Retardo do Crescimento Fetal/imunologia , Retardo do Crescimento Fetal/patologia , Regulação da Expressão Gênica , Idade Gestacional , Histiócitos/imunologia , Histiócitos/metabolismo , Histiócitos/patologia , Histiocitose/imunologia , Histiocitose/metabolismo , Histiocitose/patologia , Humanos , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Lectinas de Ligação a Manose/genética , Lectinas de Ligação a Manose/metabolismo , Placenta/imunologia , Placenta/patologia , Doenças Placentárias/imunologia , Doenças Placentárias/metabolismo , Doenças Placentárias/patologia , Gravidez , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Receptores de Complemento/metabolismo , Estudos Retrospectivos , Transcriptoma , Adulto Jovem
16.
Exp Mol Med ; 51(4): 1-13, 2019 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-30967528

RESUMO

Precise spatiotemporal regulation of leukocyte extravasation is key for generating an efficient immune response to injury or infection. The integrins LFA-1(CD11a/CD18) and Mac-1(CD11b/CD18) play overlapping roles in neutrophil migration because they bind the same as well as different ligands in response to extracellular signaling. Using two-photon intravital imaging and transmission electron microscopy, we observed the existence of preferred sites for neutrophil entrance into the endothelial cell monolayer and exit from the basement membrane and pericyte sheath during neutrophil extravasation, namely, hotspots I and II, by elucidating distinctive roles of LFA-1 and Mac-1. To penetrate the vascular endothelium, neutrophils must first penetrate the endothelial cell layer through hotspot I (i.e., the point of entry into the endothelium). Neutrophils frequently remain in the space between the endothelial cell layer and the basement membrane for a prolonged period (>20 min). Subsequently, neutrophils penetrate the basement membrane and pericyte sheath at hotspot II, which is the final stage of exiting the vascular endothelium. To further investigate the roles of LFA-1 and Mac-1, we newly generated LFA-1 FRET (CD11a-YFP/CD18-CFP) mice and Mac-1 FRET (CD11b-YFP/CD18-CFP) mice. Using both FRET mice, we were able to determine that LFA-1 and Mac-1 distinctly regulate the neutrophil extravasation cascade. Our data suggest that the vascular endothelium functions as a double-layered barrier in the steps of neutrophil extravasation. We propose that the harmonized regulation of neutrophil penetration through the endothelium via hotspots I and II may be critical for vascular homeostasis during inflammation.


Assuntos
Antígeno CD11b/metabolismo , Antígenos CD18/metabolismo , Antígeno-1 Associado à Função Linfocitária/metabolismo , Neutrófilos/metabolismo , Animais , Western Blotting , Antígeno CD11b/genética , Antígenos CD18/genética , Inflamação/genética , Inflamação/metabolismo , Antígeno-1 Associado à Função Linfocitária/genética , Antígeno de Macrófago 1/genética , Antígeno de Macrófago 1/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica , Microscopia Eletrônica de Transmissão , Neutrófilos/ultraestrutura
17.
Eur Rev Med Pharmacol Sci ; 23(7): 2750-2755, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31002125

RESUMO

OBJECTIVE: Gene mutation is closely related to the occurrence of tumor. Renal cell carcinoma is a malignant tumor, seriously threatening patients' life quality. Regulatory T cells (Treg) play important roles in the development of several cancers. This study aimed to investigate whether CD18 affects renal carcinoma cell proliferation. MATERIALS AND METHODS: Thirty mice with renal cell carcinoma were constructed using gene-engineering mouse with CD18 deficiency, and another 30 normal C57 mice were used as control. Ki67 and micro-vessel density were detected by using immunohistochemistry (IHC) and immunofluorescence, respectively. The expression of CD3, CD4 and CD8 were detected in blood and spleen by quantitative PCR (q-PCR). Flow cytometry was used to detect the changes of Treg cells. RESULTS: The expression of Ki67 in C57 was significantly higher than that in CD18-/- mice (p<0.05). IHC results showed that CD31 was also significantly downregulated in CD18-/- group compared to control group (p<0.05). It was found that only high expression of CD4 in mesenteric lymph nodes of CD18-/- was considered as non-tumor-bearing. Flow cytometry results showed that Treg cells were significantly decreased in CD18-/- compared to C57 group (p<0.05). CONCLUSIONS: CD18-/- down-regulates Treg cells and inhibits the pathogenesis of renal cell carcinoma.


Assuntos
Antígenos CD18/metabolismo , Carcinoma de Células Renais/metabolismo , Neoplasias Renais/patologia , Linfócitos T Reguladores/metabolismo , Animais , Linfócitos T CD4-Positivos/metabolismo , Progressão da Doença , Regulação para Baixo , Feminino , Citometria de Fluxo/métodos , Antígeno Ki-67/metabolismo , Linfonodos/metabolismo , Masculino , Mesentério/patologia , Camundongos , Camundongos Endogâmicos C57BL
19.
J Clin Immunol ; 39(3): 309-315, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30919141

RESUMO

PURPOSE: We aimed to report the characteristics of leukocyte adhesion deficiency-I (LAD-I) and four novel mutations in the ITGB2 gene in a Chinese cohort. METHODS: Seven patients with LAD-I were reported in our study. Clinical manifestations and immunological phenotypes were reviewed. The expression of CD18 was detected by flow cytometry. Next-generation sequencing (NGS) and Sanger sequencing were performed to identify gene mutations. RESULTS: The mean onset age of all the patients was 1.3 months. Recurrent bacterial infections of the skin and lungs were the most common symptoms. Most patients (6/7) had delayed cord separation. The number of white blood cells (WBC) was increased significantly, except that two patients had a mild increase in the number of WBC during infection-free periods. The expression of CD18 was very low in all patients. Homozygous or compound heterozygous mutations in the ITGB2 gene were identified in each patient. Four mutations were novel, including c.1794dupC (p.N599Qfs*93), c.1788C>A (p.C596X), c.841-849del9, and c.741+1delG. Two patients had large deletions of the ITGB2 gene. Five patients were cured by hematopoietic stem cell transplantation (HSCT). CONCLUSIONS: This study reported the clinical and molecular characteristics of a Chinese patient cohort. It is helpful in understanding the current status of the disease in China.


Assuntos
Autoantígenos/genética , Síndrome da Aderência Leucocítica Deficitária/genética , Mutação/genética , Colágenos não Fibrilares/genética , Infecções Bacterianas , Antígenos CD18/metabolismo , China , Estudos de Coortes , Feminino , Transplante de Células-Tronco Hematopoéticas , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lactente , Masculino
20.
Biochem Biophys Res Commun ; 511(2): 312-317, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30777333

RESUMO

We reported previously that leukocyte ß2 integrins (LFA-1 and Mac-1) bind to the serine/threonine-rich domain of thrombomodulin (TM) expressed on vascular endothelial cells (VECs). Recombinant human soluble TM (rhsTM, TMD123) has been approved as a therapeutic drug for septic disseminated intravascular coagulation. However, the roles of TMD123 on the adhesion of leukocyte integrins to VECs remain unclear. In the current study, we have revealed that an integrin-dependent binding between human peripheral blood mononuclear cells (PBMCs) and VECs was inhibited by TMD123. Next, using mutant proteins composed of isolated TM extracellular domains, we examined the structural characteristics responsible for the anti-adhesion properties of TMD123. Namely, we investigated whether the effects of the binding of TM and leukocytes was inhibited by the administration of TMD123. In fact, we confirmed that TMD123, TMD1, and TMD3 inhibited the binding of PBMCs to the immobilized recombinant proteins TMD123 and TMD3. These results indicate that TMD123 inhibited the adhesion of leukocytes to endothelial cells via ß2 integrins and endothelial TM. Moreover, since TMD1 might bind to leukocytes via other adhesion receptors than integrins, TMD1 and TMD3 appear to inhibit leukocyte binding to TM on VECs via different mechanisms. In summary, TMD123 (rhsTM), TMD1 or TMD3 is a promising treatment option for sepsis that attenuates integrin-dependent binding of leukocytes to VECs, and may inhibit the undesirable adhesion and migration of leukocytes to VECs in sepsis.


Assuntos
Adesão Celular , Células Endoteliais/citologia , Leucócitos/citologia , Trombomodulina/metabolismo , Antígenos CD18/metabolismo , Comunicação Celular , Células Cultivadas , Células Endoteliais/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Leucócitos/metabolismo , Domínios Proteicos , Trombomodulina/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA