Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
1.
Spectrochim Acta A Mol Biomol Spectrosc ; 312: 124066, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38428213

RESUMO

The Coronavirus Disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has required the search for sensitive, rapid, specific, and lower-cost diagnostic methods to meet the high demand. The gold standard method of laboratory diagnosis is real-time reverse transcription polymerase chain reaction (RT-PCR). However, this method is costly and results can take time. In the literature, several studies have already described the potential of Fourier transform infrared spectroscopy (FTIR) as a tool in the biomedical field, including the diagnosis of viral infections, while being fast and inexpensive. In view of this, the objective of this study was to develop an FTIR model for the diagnosis of COVID-19. For this analysis, all private clients who had performed a face-to-face collection at the Univates Clinical Analysis Laboratory (LAC Univates) within a period of six months were invited to participate. Data from clients who agreed to participate in the study were collected, as well as nasopharyngeal secretions and a saliva sample. For the development of models, the RT-PCR result of nasopharyngeal secretions was used as a reference method. Absorptions with high discrimination (p < 0.001) between GI (28 patients, RT-PCR test positive to SARS-CoV-2 virus) and GII (173 patients who did not have the virus detected in the test) were most relevant at 3512 cm-1, 3385 cm-1 and 1321 cm-1 after 2nd derivative data transformation. To carry out the diagnostic modeling, chemometrics via FTIR and Discriminant Analysis of Orthogonal Partial Least Squares (OPLS-DA) by salivary transflectance mode with one latent variable and one orthogonal signal correction component were used. The model generated predictions with 100 % sensitivity, specificity and accuracy. With the proposed model, in a single application of an individual's saliva in the FTIR equipment, results related to the detection of SARS-CoV-2 can be obtained in a few minutes of spectral evaluation.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico , SARS-CoV-2 , Saliva , Quimiometria , Espectrofotometria Infravermelho , Sensibilidade e Especificidade
2.
Semin Immunopathol ; 44(4): 445-459, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35122118

RESUMO

Tumour necrosis factor-α (TNF) is a multifunctional cytokine. First recognized as an endogenous soluble factor that induces necrosis of solid tumours, TNF became increasingly important as pro-inflammatory cytokine being involved in the immunopathogenesis of several autoimmune diseases. In the liver, TNF induces numerous biological responses such as hepatocyte apoptosis and necroptosis, liver inflammation and regeneration, and autoimmunity, but also progression to hepatocellular carcinoma. Considering these multiple functions of TNF in the liver, we propose anti-TNF therapies that specifically target TNF signalling at the level of its specific receptors.


Assuntos
Neoplasias Hepáticas , Fator de Necrose Tumoral alfa , Citocinas , Humanos , Inflamação/patologia , Fígado/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/patologia , Inibidores do Fator de Necrose Tumoral
3.
Cell Mol Immunol ; 18(1): 92-111, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33110250

RESUMO

The liver is an important immunological organ that controls systemic tolerance. The liver harbors professional and unconventional antigen-presenting cells that are crucial for tolerance induction and maintenance. Orchestrating the immune response in homeostasis depends on a healthy and well-toned immunological liver microenvironment, which is maintained by the crosstalk of liver-resident antigen-presenting cells and intrahepatic and liver-infiltrating leukocytes. In response to pathogens or autoantigens, tolerance is disrupted by unknown mechanisms. Intrahepatic parenchymal and nonparenchymal cells exhibit unique antigen-presenting properties. The presentation of microbial and endogenous lipid-, metabolite- and peptide-derived antigens from the gut via conventional and nonconventional mechanisms can educate intrahepatic immune cells and elicit effector responses or tolerance. Perturbation of this balance results in autoimmune liver diseases, such as autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis. Although the exact etiologies of these autoimmune liver diseases are unknown, it is thought that the disruption of tolerance towards self-antigens and microbial metabolites and lipids, as well as alterations in bile acid composition, may result in changes in effector cell activation and polarization and may reduce or impair protective anti-inflammatory regulatory T and B cell responses. Additionally, the canonical and noncanonical transmission of antigens and antigen:MHC complexes via trogocytosis or extracellular vesicles between different (non) immune cells in the liver may play a role in the induction of hepatic inflammation and tolerance. Here, we summarize emerging aspects of antigen presentation, autoantibody production, and the application of novel therapeutic approaches in the characterization and treatment of autoimmune liver diseases.


Assuntos
Apresentação de Antígeno/imunologia , Células Apresentadoras de Antígenos/imunologia , Autoanticorpos/imunologia , Doenças Autoimunes/imunologia , Tolerância Imunológica , Hepatopatias/imunologia , Linfócitos T Reguladores/imunologia , Animais , Doenças Autoimunes/terapia , Humanos , Hepatopatias/terapia
4.
Neuro Oncol ; 22(7): 955-966, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32064501

RESUMO

BACKGROUND: Brain metastasis (BM) in non-small-cell lung cancer (NSCLC) has a very poor prognosis. Recent studies have demonstrated the importance of cell adhesion molecules in tumor metastasis. The aim of our study was to investigate the role of activated leukocyte cell adhesion molecule (ALCAM) in BM formation in NSCLC. METHODS: Immunohistochemical analysis was performed on 143 NSCLC primary tumors and BM. A correlation between clinicopathological parameters and survival was developed. Biological properties of ALCAM were assessed in vitro by gene ablation using CRISPR/Cas9 technology in the NCI-H460 NSCLC cell line and in vivo by intracranial and intracardial cell injection of NCI-H460 cells in NMRI-Foxn1nu/nu mice. RESULTS: ALCAM expression was significantly upregulated in NSCLC brain metastasis (P = 0.023) with a de novo expression of ALCAM in 31.2% of BM. Moderate/strong ALCAM expression in both primary NSCLC and brain metastasis was associated with shortened survival. Functional analysis of an ALCAM knock-out (KO) cell line showed a significantly decreased cell adhesion capacity to human brain endothelial cells by 38% (P = 0.045). In vivo studies showed significantly lower tumor cell dissemination in mice injected with ALCAM-KO cells in both mouse models, and both the number and size of BM were significantly diminished in ALCAM depleted tumors. CONCLUSIONS: Our findings suggest that elevated levels of ALCAM expression promote BM formation in NSCLC through increased tumor cell dissemination and interaction with the brain endothelial cells. Therefore, ALCAM could be targeted to reduce the occurrence of BM. KEY POINTS: 1. ALCAM expression associates with poor prognosis and brain metastasis in NSCLC.2. ALCAM mediates interaction of NSCLC tumor cells with brain vascular endothelium.3. ALCAM might represent a novel preventive target to reduce the occurrence of BM in NSCLC.


Assuntos
Neoplasias Encefálicas , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Molécula de Adesão de Leucócito Ativado , Animais , Neoplasias Encefálicas/secundário , Células Endoteliais , Endotélio Vascular , Feminino , Humanos , Masculino , Camundongos
5.
Front Immunol ; 10: 2670, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31798592

RESUMO

The clearance of apoptotic cells is pivotal for both maintaining tissue homeostasis and returning to homeostasis after tissue injury as part of the regenerative resolution response. The liver is known for its capacity to remove aged and damaged cells from the circulation and can serve as a graveyard for effector T cells. In particular Kupffer cells are active phagocytic cells, but during hepatic inflammatory responses incoming neutrophils and monocytes may contribute to pro-inflammatory damage. To stimulate resolution of such inflammation, myeloid cell function can change, via sensing of environmental changes in the inflammatory milieu. Also, the removal of apoptotic cells via efferocytosis and the signaling pathways that are activated in macrophages/phagocytes upon their engulfment of apoptotic cells are important for a return to tissue homeostasis. Here, we will discuss, how efferocytosis mechanisms in hepatic macrophages/phagocytes may regulate tissue homeostasis and be involved in tissue regeneration in liver disease.


Assuntos
Homeostase/fisiologia , Fígado/metabolismo , Macrófagos/metabolismo , Fagocitose/fisiologia , Animais , Humanos , Fígado/imunologia , Hepatopatias/imunologia , Hepatopatias/metabolismo , Macrófagos/imunologia
6.
Inflamm Bowel Dis ; 25(2): 294-305, 2019 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-30295747

RESUMO

Background: Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) displays multiple activities, among which pathogen binding and angiogenesis are particularly prominent. These same functions are also exerted by Toll- and NOD-like receptors (TLRs and NLRs), which are critical mediators of innate immune responses. We investigated whether a functional inter-relationship exists between CEACAM1 and TLRs and NLRs and its potential impact on induction of intestinal angiogenesis. Methods: This hypothesis was tested using human intestinal microvascular endothelial cells, a unique cell population exposed to microbial products under physiological and pathological conditions. Results: The results show that activation of TLR2/4, TLR4, NOD1, and NOD2 by specific bacterial ligands selectively and differentially upregulates the levels of cellular and soluble CEACAM1 produced by intestinal microvascular endothelial cells. The results also show that CEACAM1 regulates the migration, transmigration, and tube formation of these endothelial cells and mediates vessel sprouting induced by specific TLR and NLR bacterial ligands. Combined, these results demonstrate a close and reciprocal regulatory interaction between CEACAM1 and bacterial products in mediating multiple functions essential to new vessel formation in the gut mucosa. Conclusions: A coordinated and reciprocal interaction of CEACAM1 and microbiota-derived factors is necessary to optimize angiogenesis in the gut mucosa. This suggests that a coordination of endogenous and exogenous innate immune responses is necessary to promote intestinal angiogenesis under physiological and inflammatory conditions such as inflammatory bowel disease.


Assuntos
Antígenos CD/metabolismo , Moléculas de Adesão Celular/metabolismo , Imunidade Inata/imunologia , Mediadores da Inflamação/metabolismo , Doenças Inflamatórias Intestinais/patologia , Mucosa Intestinal/patologia , Microvasos/patologia , Neovascularização Fisiológica , Animais , Antígenos de Bactérias/imunologia , Antígenos CD/genética , Estudos de Casos e Controles , Moléculas de Adesão Celular/antagonistas & inibidores , Moléculas de Adesão Celular/genética , Movimento Celular , Proliferação de Células , Citocinas/metabolismo , Humanos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Microvasos/imunologia , Microvasos/metabolismo , Proteína Adaptadora de Sinalização NOD1/metabolismo , Proteína Adaptadora de Sinalização NOD2/metabolismo , RNA Interferente Pequeno/genética , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo
7.
Int J Mol Sci ; 19(10)2018 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-30314283

RESUMO

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a transmembrane glycoprotein that is expressed on epithelial, endothelial and immune cells. CEACAM1 is a differentiation antigen involved in the maintenance of epithelial polarity that is induced during hepatocyte differentiation and liver regeneration. CEACAM1 regulates insulin sensitivity by promoting hepatic insulin clearance, and controls liver tolerance and mucosal immunity. Obese insulin-resistant humans with non-alcoholic fatty liver disease manifest loss of hepatic CEACAM1. In mice, deletion or functional inactivation of CEACAM1 impairs insulin clearance and compromises metabolic homeostasis which initiates the development of obesity and hepatic steatosis and fibrosis with other features of non-alcoholic steatohepatitis, and adipogenesis in white adipose depot. This is followed by inflammation and endothelial and cardiovascular dysfunctions. In obstructive and inflammatory liver diseases, soluble CEACAM1 is shed into human bile where it can serve as an indicator of liver disease. On immune cells, CEACAM1 acts as an immune checkpoint regulator, and deletion of Ceacam1 gene in mice causes exacerbation of inflammation and hyperactivation of myeloid cells and lymphocytes. Hence, hepatic CEACAM1 resides at the central hub of immune and metabolic homeostasis in both humans and mice. This review focuses on the regulatory role of CEACAM1 in liver and biliary tract architecture in health and disease, and on its metabolic role and function as an immune checkpoint regulator of hepatic inflammation.


Assuntos
Antígenos CD/genética , Antígenos CD/metabolismo , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Metabolismo Energético/genética , Imunomodulação/genética , Hepatopatias/etiologia , Hepatopatias/metabolismo , Animais , Antígenos CD/química , Antígenos CD/imunologia , Proteínas de Transporte/metabolismo , Moléculas de Adesão Celular/química , Moléculas de Adesão Celular/imunologia , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/imunologia , Transformação Celular Neoplásica/metabolismo , Regulação da Expressão Gênica , Humanos , Hepatopatias/patologia , Família Multigênica , Ligação Proteica , Transdução de Sinais
8.
FASEB J ; 32(10): 5612-5625, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29746166

RESUMO

Carcinoembryonic antigen-related cell adhesion molecule-1 (CEACAM1) is known to be crucial to vasculogenesis and angiogenesis. Recently, CEACAM1 deficiency was shown to result in the formation of aortic plaque-like lesions, indicating a role for CEACAM1 in adult vessels as well. The underlying mechanisms remained largely elusive. Therefore, we aimed to elucidate the role of CEACAM1 in endothelial homeostasis. Here, we show that CEACAM1 deficiency causes subcellular eNOS redistribution in endothelial cells ( i.e., by eNOS depalmitoylation) and alters endothelial glycocalyx that confers antiadhesive properties to the endothelium ( i.e., by repression of glycocalyx-degrading enzymes). Accordingly, our analysis revealed an increased leukocyte-endothelial interaction in CEACAM1-deficient endothelium. In addition, CEACAM1 age dependently modulated basal and TNF-α-mediated endothelial barrier (EB) leakiness. In younger mice, CEACAM1 was protective for EB, whereas in aged mice it promoted EB leakiness. EB function depends on interendothelial adherence junctions formed by ß-catenin/vascular endothelial-cadherin complexes. We show here that CEACAM1 influenced basal and TNF-α-mediated phosphorylation of ß-catenin and caveolin-1, which are essential players in EB modulation. Both increased adhesiveness to leukocytes and EB modulation due to CEACAM1 deficiency may facilitate inflammatory cell transmigration into the vascular wall and subsequent plaque formation. Collectively, these results identify a crucial role for CEACAM1 in endothelial homeostasis of adult blood vessels.-Ghavampour, S., Kleefeldt, F., Bömmel, H., Volland, J., Paus, A., Horst, A., Pfeiffer, V., Hübner, S., Wagner, N., Rueckschloss, U., Ergün, S. Endothelial barrier function is differentially regulated by CEACAM1-mediated signaling.


Assuntos
Antígeno Carcinoembrionário/metabolismo , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Transdução de Sinais , Migração Transendotelial e Transepitelial , Animais , Caderinas/metabolismo , Caveolina 1/metabolismo , Células Endoteliais/patologia , Endotélio Vascular/patologia , Camundongos , Camundongos Knockout , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
9.
Hepatology ; 68(1): 200-214, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29377208

RESUMO

A dysbalance between effector T cells (Tconv) and regulatory T cells (Tregs) and impaired Treg function can cause autoimmune liver disease. Therefore, it is important to identify molecular mechanisms that control Treg homeostasis. Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1; CD66a) is an immune coreceptor with dichotomous roles in T-cell regulation: its short isoform (CEACAM1S) can activate T cells and induce Tregs, whereas its long isoform (CEACAM1L), containing two intracellular immune receptor tyrosine-based inhibitory motifs, can inhibit activated T-cell function. In the liver, CEACAM1 has antifibrotic effects in models of nonalcoholic steatohepatitis. However, its role in immune-mediated hepatitis is unknown. In the mouse model of concanavalin A-induced CD4+ T-cell-dependent liver injury, liver damage was aggravated and persisted in Ceacam1-/- mice. Concomitantly, we observed hyperexpansion of Tconv, but reduction of interleukin (IL)-2 production and hepatic forkhead box protein P3+ (Foxp3+ )CD4+ Treg numbers. CEACAM1-/- CD4+ T cells showed impaired IL-2-mediated signal transducer and activator of transcription 5 (STAT5) phosphorylation, which correlated with a failure of naïve CEACAM1-/- CD4+ T cells to convert into Tregs in vitro. Furthermore, CEACAM1-/- Tregs expressed reduced levels of Foxp3, CD25, and B-cell lymphoma 2. Adoptive transfer experiments demonstrated that hepatic Treg expansion and suppressive activity required CEACAM1 expression on both CD4+ T cells and Tregs. We identified predominant CEACAM1S expression on hepatic CD4+ T cells and Tregs from mice with acute liver injury and expression of both isoforms in liver-derived CD4+ T-cell clones from patients with liver injury. CONCLUSION: Our data suggest that CEACAM1S expression in CD4+ T cells augments IL-2 production and STAT5 phosphorylation leading to enhanced Treg induction and stability, which, ultimately, confers protection from T-cell-mediated liver injury. (Hepatology 2018;68:200-214).


Assuntos
Antígenos CD/fisiologia , Moléculas de Adesão Celular/fisiologia , Hepatite Autoimune/imunologia , Linfócitos T Reguladores/fisiologia , Animais , Estudos de Casos e Controles , Concanavalina A , Feminino , Humanos , Interleucina-2/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Cultura Primária de Células , Fator de Transcrição STAT5/metabolismo
10.
J Immunol ; 198(1): 128-137, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-27872212

RESUMO

Type 2 innate lymphoid cells (ILC2) mediate inflammatory immune responses in the context of diseases triggered by the alarmin IL-33. In recent years, IL-33 has been implicated in the pathogenesis of immune-mediated liver diseases. However, the immunoregulatory function of ILC2s in the inflamed liver remains elusive. Using the murine model of Con A-induced immune-mediated hepatitis, we showed that selective expansion of ILC2s in the liver was associated with highly elevated hepatic IL-33 expression, severe liver inflammation, and infiltration of eosinophils. CD4+ T cell-mediated tissue damage and subsequent IL-33 release were responsible for the activation of hepatic ILC2s that produced the type 2 cytokines IL-5 and IL-13 during liver inflammation. Interestingly, ILC2 depletion correlated with less severe hepatitis and reduced accumulation of eosinophils in the liver, whereas adoptive transfer of hepatic ILC2s aggravated liver inflammation and tissue damage. We further showed that, despite expansion of hepatic ILC2s, 3-d IL-33 treatment before Con A challenge potently suppressed development of immune-mediated hepatitis. We found that IL-33 not only activated hepatic ILC2s but also expanded CD4+ Foxp3+ regulatory T cells (Treg) expressing the IL-33 receptor ST2 in the liver. This Treg subset also accumulated in the liver during resolution of immune-mediated hepatitis. In summary, hepatic ILC2s are poised to respond to the release of IL-33 upon liver tissue damage through expression of type 2 cytokines thereby participating in the pathogenesis of immune-mediated hepatitis. Inflammatory activity of ILC2s might be regulated by IL-33-elicited ST2+ Tregs that also arise in immune-mediated hepatitis.


Assuntos
Hepatite Autoimune/imunologia , Ativação Linfocitária/imunologia , Linfócitos/imunologia , Transferência Adotiva , Animais , Citocinas/biossíntese , Citocinas/imunologia , Modelos Animais de Doenças , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Interleucina-33/biossíntese , Interleucina-33/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Reação em Cadeia da Polimerase em Tempo Real , Linfócitos T Reguladores/imunologia
11.
Oncotarget ; 7(39): 63730-63746, 2016 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-27572314

RESUMO

We analyzed the molecular basis for carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1)-controlled inhibition of epithelial-mesenchymal transition (EMT) in a mouse model for mammary adenocarcinoma (WAP-T mice). We demonstrate that silencing of CEACAM1 in WAP-T tumor-derived G-2 cells induces epithelial-mesenchymal plasticity (EMP), as evidenced by typical changes of gene expression, morphology and increased invasion. In contrast, reintroduction of CEACAM1 into G-2 cells reversed up-regulation of genes imposing mesenchymal transition, as well as cellular invasion. We identified the Wnt-pathway as target for CEACAM1-mediated repression of EMT. Importantly, ß-catenin phosphorylation status and transcriptional activity strongly depend on CEACAM1 expression: CEACAM1high G-2 cells displayed enhanced phosphorylation of ß-catenin at S33/S37/T41 and decreased phosphorylation at Y86, thereby inhibiting canonical Wnt/ß-catenin signaling. We identified Src-homology 2 domain-containing phosphatase 2 (SHP-2) as a critical binding partner of CEACAM1 that could modulate ß-catenin Y86 phosphorylation. Hence, CEACAM1 serves as a scaffold that controls membrane proximal ß-catenin signaling. In vivo, mammary tumors of WAP-T/CEACAM1null mice displayed increased nuclear translocation of ß-catenin and a dramatically enhanced metastasis rate compared to WAP-T mice. Hence, CEACAM1 controls EMT in vitro and in vivo by site-specific regulation of ß-catenin phosphorylation. Survival analyses of human mammary carcinoma patients corroborated these data, indicating that CEACAM1 is a prognostic marker for breast cancer survival.


Assuntos
Neoplasias da Mama/metabolismo , Antígeno Carcinoembrionário/metabolismo , Carcinoma/metabolismo , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Neoplasias Mamárias Experimentais/metabolismo , Animais , Antígenos CD/metabolismo , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/patologia , Moléculas de Adesão Celular/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Técnicas In Vitro , Neoplasias Mamárias Experimentais/patologia , Camundongos , Invasividade Neoplásica , Metástase Neoplásica , Fenótipo , Fosforilação , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Transdução de Sinais , Regulação para Cima , beta Catenina/metabolismo
12.
Cell Mol Immunol ; 13(3): 277-92, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27041638

RESUMO

The liver is a tolerogenic organ with exquisite mechanisms of immune regulation that ensure upkeep of local and systemic immune tolerance to self and foreign antigens, but that is also able to mount effective immune responses against pathogens. The immune privilege of liver allografts was recognized first in pigs in spite of major histo-compatibility complex mismatch, and termed the "liver tolerance effect". Furthermore, liver transplants are spontaneously accepted with only low-dose immunosuppression, and induce tolerance for non-hepatic co-transplanted allografts of the same donor. Although this immunotolerogenic environment is favorable in the setting of organ transplantation, it is detrimental in chronic infectious liver diseases like hepatitis B or C, malaria, schistosomiasis or tumorigenesis, leading to pathogen persistence and weak anti-tumor effects. The liver is a primary site of T-cell activation, but it elicits poor or incomplete activation of T cells, leading to their abortive activation, exhaustion, suppression of their effector function and early death. This is exploited by pathogens and can impair pathogen control and clearance or allow tumor growth. Hepatic priming of T cells is mediated by a number of local conventional and nonconventional antigen-presenting cells (APCs), which promote tolerance by immune deviation, induction of T-cell anergy or apoptosis, and generating and expanding regulatory T cells. This review will focus on the communication between classical and nonclassical APCs and lymphocytes in the liver in tolerance induction and will discuss recent insights into the role of innate lymphocytes in this process.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Tolerância Imunológica , Fígado/imunologia , Linfócitos T Reguladores/imunologia , Animais , Humanos , Sistema Imunitário , Fígado/ultraestrutura , Modelos Biológicos
13.
Brain Res Bull ; 121: 169-77, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26855326

RESUMO

Antioxidants have been tested to treat neuropathic pain, and α-Tocopherol (vitamin E--vit. E) and ascorbic acid (vitamin C--vit. C) are potent antioxidants. We assessed the effect of intraperitoneal administration of vit. C (30 mg/kg/day) and vit. E (15 mg/kg/day), given alone or in combination, on the mechanical and thermal thresholds and the sciatic functional index (SFI) in rats with chronic constriction injury (CCI) of the sciatic nerve. We also determined the lipid hydroperoxides and total antioxidant capacity (TAC) in the injured sciatic nerve. Further, we assessed the effects of oral administration of vit. C+vit. E (vit. C+E) and of a combination of vit. C+E and gabapentin (100mg/kg/day, i.p.) on the mechanical and thermal thresholds of CCI rats. The vitamins, whether administered orally or i.p., attenuated the reductions in the mechanical and thermal thresholds induced by CCI. The antinociceptive effect was greater with a combination of vit. C+E than with each vitamin given alone. The SFI was also improved in vitamin-treated CCI rats. Co-administration of vit. C+E and gabapentin induced a greater antinociceptive effect than gabapentin alone. No significant change occurred in TAC and lipid hydroperoxide levels, but TAC increased (45%) while lipid hydroperoxides decreased (38%) in the sciatic nerve from vit. C+E-treated CCI rats. Thus, treatment with a combination of vit. C+E was more effective to treat CCI-induced neuropathic pain than vitamins alone, and the antinociceptive effect was greater with co-administration of vit. C+E and gabapentin than with gabapentin alone.


Assuntos
Analgésicos/uso terapêutico , Ácido Ascórbico/administração & dosagem , Nociceptividade/efeitos dos fármacos , Ciática/tratamento farmacológico , Vitamina E/administração & dosagem , Alanina Transaminase/metabolismo , Análise de Variância , Animais , Antioxidantes/metabolismo , Aspartato Aminotransferases/metabolismo , Constrição , Modelos Animais de Doenças , Hiperalgesia/tratamento farmacológico , Hiperalgesia/fisiopatologia , Locomoção/efeitos dos fármacos , Masculino , Medição da Dor , Limiar da Dor/efeitos dos fármacos , Estimulação Física/efeitos adversos , Ratos , Ratos Wistar , Ciática/etiologia , Fatores de Tempo , gama-Glutamiltransferase/metabolismo
14.
J Immunol ; 195(8): 3675-84, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26363054

RESUMO

The cytosolic protein Sharpin is a component of the linear ubiquitin chain assembly complex, which regulates NF-κB signaling in response to specific ligands, such as TNF-α. Its inactivating mutation in chronic proliferative dermatitis mutation (Cpdm) mice causes multiorgan inflammation, yet this phenotype is not transferable into wild-type mice by hematopoietic stem cell transfer. Recent evidence demonstrated that Cpdm mice additionally display low bone mass, and that this osteopenia is corrected by Tnf deletion. Because the cellular mechanism underlying this pathology, however, was still undefined, we performed a thorough skeletal phenotyping of Cpdm mice on the basis of nondecalcified histology and cellular and dynamic histomorphometry. We show that the trabecular and cortical osteopenia in Cpdm mice is solely explained by impaired bone formation, whereas osteoclastogenesis is unaffected. Consistently, Cpdm primary calvarial cells display reduced osteogenic capacity ex vivo, and the same was observed with CD11b(-) bone marrow cells. Unexpectedly, short-term treatment of these cultures with TNF-α did not reveal an impaired molecular response in the absence of Sharpin. Instead, genome-wide and gene-specific expression analyses revealed that Cpdm mesenchymal cells display increased responsiveness toward TNF-α-induced expression of specific cytokines, such as CXCL5, IL-1ß, and IL-6. Therefore, our data not only demonstrate that the skeletal defects of Cpdm mice are specifically caused by impaired differentiation of osteoprogenitor cells, they also suggest that increased cytokine expression in mesenchymal bone marrow cells contributes to the inflammatory phenotype of Cpdm mice.


Assuntos
Células da Medula Óssea/imunologia , Proteínas de Transporte/imunologia , Diferenciação Celular/imunologia , Células-Tronco Mesenquimais/imunologia , Osteogênese/imunologia , Animais , Células da Medula Óssea/patologia , Proteínas de Transporte/genética , Diferenciação Celular/genética , Citocinas/genética , Citocinas/imunologia , Dermatite/genética , Dermatite/imunologia , Dermatite/patologia , Peptídeos e Proteínas de Sinalização Intracelular , Células-Tronco Mesenquimais/patologia , Camundongos , Camundongos Mutantes , Osteogênese/genética
15.
Chembiochem ; 16(14): 2023-8, 2015 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-26296625

RESUMO

The effect of galectin-mediated microdomain formation on the spatiotemporal dynamics of glycosylated membrane proteins in human microvascular endothelial cells (HMEC-1) was studied qualitatively and quantitatively by high-resolution fluorescence microscopy and artificially mimicked by metabolic glycoprotein engineering. Two types of membrane proteins, sialic acid-bearing proteins (SABPs) and mucin-type proteins (MTPs), were investigated. For visualization they were metabolically labeled with azido sugars and then coupled to a cyclooctyne-conjugated fluorescent dye by click chemistry. Both spatial (diffusion) and temporal (residence time) dynamics of SABPs and MTPs on the membrane were investigated after treatment with exogenous galectin-1 or -3. Strong effects of galectin-mediated lattice formation were observed for MTPs (decreased spatial mobility), but not for SABPs. Lattice formation also strongly decreased the turnover of MTPs (increased residence time on the cell membrane). The effects of galectin-mediated crosslinking was accurately mimicked by streptavidin-mediated crosslinking of biotin-tagged glycoproteins and verified by single-molecule tracking. This technique allows the induction of crosslinking of membrane proteins under precisely controlled conditions, thereby influencing membrane residence time and the spatial dynamics of glycans on the cell membrane in a controlled way.


Assuntos
Células Endoteliais/metabolismo , Galectinas/metabolismo , Glicoproteínas de Membrana/metabolismo , Microdomínios da Membrana/metabolismo , Linhagem Celular , Difusão , Células Endoteliais/citologia , Humanos , Glicoproteínas de Membrana/análise , Microdomínios da Membrana/ultraestrutura , Mucinas/análise , Mucinas/metabolismo , Ácidos Siálicos/análise , Ácidos Siálicos/metabolismo
16.
Biomed Res Int ; 2015: 719316, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26146628

RESUMO

Arteriogenesis is an inflammatory process associated with rapid cellular changes involving vascular resident endothelial progenitor cells (VR-EPCs). Extracellular cell surface bound 20S proteasome has been implicated to play an important role in inflammatory processes. In our search for antigens initially regulated during collateral growth mAb CTA 157-2 was generated against membrane fractions of growing collateral vessels. CTA 157-2 stained endothelium of growing collateral vessels and the cell surface of VR-EPCs. CTA 157-2 bound a protein complex (760 kDa) that was identified as 26 kDa α7 and 21 kDa ß3 subunit of 20S proteasome in mass spectrometry. Furthermore we demonstrated specific staining of 20S proteasome after immunoprecipitation of VR-EPC membrane extract with CTA 157-2 sepharose beads. Functionally, CTA 157-2 enhanced concentration dependently AMC (7-amino-4-methylcoumarin) cleavage from LLVY (N-Succinyl-Leu-Leu-Val-Tyr) by recombinant 20S proteasome as well as proteasomal activity in VR-EPC extracts. Proliferation of VR-EPCs (BrdU incorporation) was reduced by CTA 157-2. Infusion of the antibody into the collateral circulation reduced number of collateral arteries, collateral proliferation, and collateral conductance in vivo. In conclusion our results indicate that extracellular cell surface bound 20S proteasome influences VR-EPC function in vitro and collateral growth in vivo.


Assuntos
Vasos Sanguíneos/imunologia , Circulação Colateral/imunologia , Inflamação/imunologia , Complexo de Endopeptidases do Proteassoma/imunologia , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/imunologia , Antígenos de Superfície/imunologia , Vasos Sanguíneos/crescimento & desenvolvimento , Proliferação de Células/efeitos dos fármacos , Células Endoteliais/imunologia , Células Progenitoras Endoteliais/imunologia , Inflamação/patologia , Ratos
17.
J Clin Invest ; 125(4): 1726-38, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25774501

RESUMO

Intrauterine growth restriction (IUGR) affects up to 10% of pregnancies in Western societies. IUGR is a strong predictor of reduced short-term neonatal survival and impairs long-term health in children. Placental insufficiency is often associated with IUGR; however, the molecular mechanisms involved in the pathogenesis of placental insufficiency and IUGR are largely unknown. Here, we developed a mouse model of fetal-growth restriction and placental insufficiency that is induced by a midgestational stress challenge. Compared with control animals, pregnant dams subjected to gestational stress exhibited reduced progesterone levels and placental heme oxygenase 1 (Hmox1) expression and increased methylation at distinct regions of the placental Hmox1 promoter. These stress-triggered changes were accompanied by an altered CD8+ T cell response, as evidenced by a reduction of tolerogenic CD8+CD122+ T cells and an increase of cytotoxic CD8+ T cells. Using progesterone receptor- or Hmox1-deficient mice, we identified progesterone as an upstream modulator of placental Hmox1 expression. Supplementation of progesterone or depletion of CD8+ T cells revealed that progesterone suppresses CD8+ T cell cytotoxicity, whereas the generation of CD8+CD122+ T cells is supported by Hmox1 and ameliorates fetal-growth restriction in Hmox1 deficiency. These observations in mice could promote the identification of pregnancies at risk for IUGR and the generation of clinical interventional strategies.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Desenvolvimento Fetal/fisiologia , Retardo do Crescimento Fetal/prevenção & controle , Heme Oxigenase-1/fisiologia , Proteínas de Membrana/fisiologia , Placenta/imunologia , Insuficiência Placentária/imunologia , Complicações na Gravidez/imunologia , Progesterona/fisiologia , Estresse Psicológico/imunologia , Animais , Metilação de DNA , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Feminino , Retardo do Crescimento Fetal/imunologia , Feto/imunologia , Feto/patologia , Heme Oxigenase-1/biossíntese , Heme Oxigenase-1/genética , Masculino , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Ruído/efeitos adversos , Placenta/metabolismo , Circulação Placentária , Insuficiência Placentária/etiologia , Gravidez , Complicações na Gravidez/genética , Complicações na Gravidez/psicologia , Progesterona/biossíntese , Progesterona/uso terapêutico , Regiões Promotoras Genéticas , RNA Mensageiro/genética , Estresse Psicológico/genética
18.
Angew Chem Int Ed Engl ; 54(1): 285-8, 2015 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-25346525

RESUMO

A picosecond IR laser (PIRL) can be used to blast proteins out of tissues through desorption by impulsive excitation (DIVE) of intramolecular vibrational states of water molecules in the cell in less than a millisecond. With PIRL-DIVE proteins covering a range of a few kDa up to several MDa are extracted in high quantities compared to conventional approaches. The chemical composition of extracted proteins remains unaltered and even enzymatic activities are maintained.


Assuntos
Lasers , Proteínas/isolamento & purificação , Animais , Raios Infravermelhos , Fígado/química , Camundongos , Músculos/química , Proteômica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
19.
J Manipulative Physiol Ther ; 38(2): 119-29, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25487299

RESUMO

OBJECTIVE: The purpose of this study was to investigate oxidative-stress parameters in individuals with chronic neck or back pain after 5 weeks of treatment with high-velocity, low-amplitude (HVLA) spinal manipulation. METHODS: Twenty-three individuals aged 38.2 ± 11.7 years with nonspecific chronic neck or back pain verified by the Brazilian Portuguese version of the Chronic Pain Grade, with a sedentary lifestyle, no comorbidities, and not in adjuvant therapy, underwent treatment with HVLA chiropractic manipulation twice weekly for 5 weeks. Therapeutic procedures were carried out by an experienced chiropractor. Blood samples were assessed before and after treatment to determine the activities of the antioxidant enzymes superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx), and the levels of nitric oxide metabolites and lipid hydroperoxides. These blood markers were analyzed by paired Student t test. Differences were considered statistically significant, when P was <.05. RESULTS: There was no change in catalase but an increase in SOD (0.35 ± 0.03 U SOD per milligram of protein vs 0.44 ± 0.04 U SOD per milligram of protein; P < .05) and GPx (7.91 ± 0.61 nmol/min per milligram of protein vs 14.07 ± 1.07 nmol/min per milligram of protein; P < .001) activities after the treatment. The nitric oxide metabolites and the lipid hydroperoxides did not change after treatment. CONCLUSION: High-velocity, low-amplitude spinal manipulation twice weekly for 5 weeks increases the SOD and GPx activities. Previous studies have shown a relationship between pain and oxidative and nitrosative parameters; thus, it is possible that changes in these enzymes might be related to the analgesic effect of HVLA spinal manipulation.


Assuntos
Dor Lombar/reabilitação , Manipulação Quiroprática/métodos , Manipulação da Coluna/métodos , Cervicalgia/reabilitação , Estresse Oxidativo/fisiologia , Adulto , Biomarcadores/sangue , Brasil , Catalase/metabolismo , Dor Crônica/reabilitação , Estudos de Coortes , Feminino , Humanos , Dor Lombar/sangue , Dor Lombar/diagnóstico , Masculino , Pessoa de Meia-Idade , Cervicalgia/sangue , Cervicalgia/diagnóstico , Óxido Nítrico/sangue , Índice de Gravidade de Doença , Superóxido Dismutase/sangue , Resultado do Tratamento
20.
PLoS One ; 9(12): e114360, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25490771

RESUMO

Alterations in bone remodeling are a major public health issue, as therapeutic options for widespread bone disorders such as osteoporosis and tumor-induced osteolysis are still limited. Therefore, a detailed understanding of the regulatory mechanism governing bone cell differentiation in health and disease are of utmost clinical importance. Here we report a novel function of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), a member of the immunoglobulin superfamily involved in inflammation and tumorigenesis, in the physiologic regulation of bone remodeling. Assessing the expression of all members of the murine Ceacam family in bone tissue and marrow, we found CEACAM1 and CEACAM10 to be differentially expressed in both bone-forming osteoblasts and bone-resorbing osteoclasts. While Ceacam10-deficient mice displayed no alteration in structural bone parameters, static histomorphometry demonstrated a reduced trabecular bone mass in mice lacking CEACAM1. Furthermore, cellular and dynamic histomorphometry revealed an increased osteoclast formation in Ceacam1-deficient mice, while osteoblast parameters and the bone formation rate remained unchanged. In line with these findings, we detected accelerated osteoclastogenesis in Ceacam1-deficient bone marrow cells, while osteoblast differentiation, as determined by mineralization and alkaline phosphatase assays, was not affected. Therefore, our results provide in vivo and in vitro evidence for a physiologic role of CEACAM1 in the regulation of osteoclastogenesis.


Assuntos
Moléculas de Adesão Celular/deficiência , Osteoclastos/citologia , Animais , Antígenos CD/genética , Medula Óssea/metabolismo , Remodelação Óssea , Moléculas de Adesão Celular/genética , Linhagem Celular , Regulação da Expressão Gênica , Camundongos , Fatores de Transcrição NFATC/metabolismo , Osteoblastos/citologia , Osteoblastos/metabolismo , Osteoclastos/metabolismo , Osteogênese , Fenótipo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA