RESUMO
As one innate immune pattern recognition receptor, Toll-like receptor 4 (TLR4) recently has been considered as a critical player in glucolipid metabolism. Blueberries contain high level of anthocyanins, especially malvidin-3-glucoside (Mv-3-glc), which contribute the anti-inflammatory, hypoglycemic, and hypolipidemic effects. It is speculated that Mv-3-glc is able to possess these functions by binding to TLR4. Here, the noncovalent interactions of Mv-3-glc and TLR4 was explored through multi-techniques including fluorescence and ultraviolet-visible (UV-Vis) absorption spectroscopy, as well as molecular docking. The results demonstrated that Mv-3-glc was able to quench TLR4 intrinsic fluorescence effectively. A stable complex was formed spontaneously and the reaction was exothermic. The degree of binding of Mv-3-glc to TLR4 showed a strong dependence on the chemical concentration, temperature, and pH values. The negative signs for enthalpy (ΔH = -69.1 ± 10.8 kJ/mol) and entropy (ΔS = -105.0 ± 12.3 J/mol/K) from the interaction of the Mv-3-glc and TLR4 shows that the major driving forces are the hydrogen bonding and van der Waals' force, which is consistent with the molecular docking results. In addition, molecular docking predicted that the active center with specific amino acid residues, Phe126, Ser127, Leu54, Ile153, and Tyr131 was responsible for the site of Mv-3-glc binding to TLR4/myeloid differentiation protein-2 (MD-2). These findings confirmed that Mv-3-glc could bind to TLR4, which would be beneficial to understand the target therapeutic effects of blueberry anthocyanins on TLR4 in regulating glucolipid metabolism.
Assuntos
Antocianinas , Glucosídeos , Simulação de Acoplamento Molecular , Espectrometria de Fluorescência , Receptor 4 Toll-Like , Receptor 4 Toll-Like/metabolismo , Receptor 4 Toll-Like/química , Glucosídeos/química , Glucosídeos/metabolismo , Antocianinas/química , Antocianinas/metabolismo , Antocianinas/farmacologia , Humanos , Ligação Proteica , Espectrofotometria Ultravioleta , Termodinâmica , Ligação de Hidrogênio , Sítios de LigaçãoRESUMO
Acute lung injury (ALI) is a serious and common clinical disease. Despite significant progress in ALI treatment, the morbidity and mortality rates remain high. However, no effective drug has been discovered for ALI. FGF4, a member of the FGF family, plays an important role in the regulation of various physiological and pathological processes. Therefore, in the present study, we aimed to study the protective effects of FGF4 against LPS-induced lung injury in vivo and in vitro. We found that rFGF4 treatment improved the lung W/D weight ratio, the survival rate, immune cell infiltration and protein concentrations in mice with LPS-induced ALI. Histological analysis revealed that rFGF4 significantly attenuated lung tissue injury and cell apoptosis. Furthermore, rFGF4 inhibited the activation of the TLR4/NF-κB signaling pathway and the production of pro-inflammatory mediators in LPS-injured lung tissues, murine alveolar macrophages (MH-S) and murine pulmonary epithelial (MLE-12) cells. The results of cell experiments further verified that rFGF4 inhibited the production of inflammatory mediators in MH-S cells and MLE-12 cells by regulating the TLR4/NF-κB signaling pathway. These results revealed that rFGF4 protected lung tissues and inhibited inflammatory mediators in mice with LPS-induced ALI by inhibiting the TLR4/NF-κB signaling pathway in MH-S and MLE-12 cells.
Assuntos
Lesão Pulmonar Aguda , NF-kappa B , Camundongos , Animais , NF-kappa B/metabolismo , Lipopolissacarídeos , Receptor 4 Toll-Like/metabolismo , Transdução de Sinais , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/metabolismo , Pulmão/patologia , Mediadores da InflamaçãoRESUMO
Paclitaxel is a microtubule-stabilizing chemotherapeutic agent approved for the treatment of ovarian, non-small cell lung, head, neck, and breast cancers. Despite its beneficial effects on cancer and widespread use, paclitaxel also damages healthy tissues, including the skin. However, the mechanisms that drive these skin adverse events are not clearly understood. In the present study, we demonstrated, by using both primary epidermal keratinocytes (NHEK) and a 3D epidermis model, that paclitaxel impairs different cellular processes: paclitaxel increased the release of IL-1α, IL-6, and IL-8 inflammatory cytokines, produced reactive oxygen species (ROS) release and apoptosis, and reduced the endothelial tube formation in the dermal microvascular endothelial cells (HDMEC). Some of the mechanisms driving these adverse skin events in vitro are mediated by the activation of toll-like receptor 4 (TLR-4), which phosphorylate transcription of nuclear factor kappa B (NF-κb). This is the first study analyzing paclitaxel effects on healthy human epidermal cells with an epidermis 3D model, and will help in understanding paclitaxel's effects on the skin.
Assuntos
Citocinas/metabolismo , Epiderme/metabolismo , Queratinócitos/citologia , Paclitaxel/efeitos adversos , Espécies Reativas de Oxigênio/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Células 3T3 BALB , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Derme/citologia , Derme/efeitos dos fármacos , Derme/metabolismo , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Epiderme/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-1alfa/metabolismo , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Camundongos , NF-kappa B/metabolismo , Paclitaxel/farmacologia , Fosforilação/efeitos dos fármacosRESUMO
Toll-like receptor 4 (TLR4) is best known for its role in bacteria-produced lipopolysaccharide recognition. Regarding female reproduction, TLR4 is expressed by murine cumulus cells and participates in ovulation and in cumulus-oocyte complex (COC) expansion, maternal-fetal interaction and preterm labour. Despite these facts, the role of TLR4 in ovarian physiology is not fully understood. Therefore, the aim of the present study was to investigate the effects of TLR4 genetic ablation on mice folliculogenesis and female fertility, through analysis of reproductive crosses, ovarian responsiveness and follicular quantification in TLR4-/- (n = 94) and C57BL/6 mice [wild type (WT), n = 102]. TLR4-deficient pairs showed a reduced number of pups per litter (P = 0.037) compared with WT. TLR4-/- mice presented more primordial, primary, secondary and antral follicles (P < 0.001), however there was no difference in estrous cyclicity (P > 0.05). A lower (P = 0.006) number of COC was recovered from TLR4-/- mice oviducts after superovulation, and in heterozygous pairs, TLR4-/- females also showed a reduction in the pregnancy rate and in the number of fetuses per uterus (P = 0.007) when compared with WT. Altogether, these data suggest that TLR4 plays a role in the regulation of murine folliculogenesis and in determining ovarian endowment. TLR4 deficiency may affect ovulation and pregnancy rates, potentially decreasing fertility, therefore the potential side effects of its blockade have to be carefully investigated.
Assuntos
Administração Financeira , Receptor 4 Toll-Like/metabolismo , Animais , Feminino , Fertilidade/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Folículo Ovariano/fisiologia , Gravidez , Receptor 4 Toll-Like/genéticaRESUMO
3-O-trans-caffeoyloleanolic acid (COA) is a pentacyclic triterpenoid compound, with significant anti-inflammatory effects. In this study, we report the protective effects of COA on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and explored its mechanism of action. LPS was used to construct in vivo mouse ALI models to observe the effects of COA pretreatment on lung pathology, inflammation, and oxidative stress. In vitro, mouse alveolar macrophages MH-S cells were cultured and stimulated with LPS to investigate the effects of COA pretreatment on inflammation and oxidative stress. Western blotting was used to investigate the expression of iNOS, TLR4, p-p65, p-AKT, and p-PI3K from in vivo and in vitro samples. The results showed that COA significantly improved lung injury, inhibited neutrophil infiltration, prevented macrophage infiltration, inhibited the release of inflammatory factors, reduced oxidative stress, and down-regulated the expression of iNOS, TLR4, p-p65, p-AKT, and p-PI3K in ALI mice caused by LPS. In vitro, COA inhibited the release of inflammatory factors, reduced oxidative stress, and down-regulated the expression of iNOS, TLR4, p-p65, p-AKT, and p-PI3K in MH-S cells stimulated with LPS. Of interest, the protective effects of COA were significantly attenuated in MH-S cells pretreated with the PI3K phosphopeptide activator 740Y-P with no effect on TLR4 expression observed. Taken together, these findings confirm the protective effects of COA on ALI. We further demonstrate that the anti-inflammation and antioxidant effects of COA are mediated through its effects on PI3K/AKT and potentially TLR4.
Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Anti-Inflamatórios/química , Ácido Oleanólico/análogos & derivados , Estresse Oxidativo/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Lipopolissacarídeos/metabolismo , Macrófagos/citologia , Masculino , Camundongos Endogâmicos BALB C , Óxido Nítrico Sintase Tipo II/metabolismo , Ácido Oleanólico/química , Ácido Oleanólico/farmacologia , Fosfopeptídeos/metabolismo , Transdução de Sinais , Receptor 4 Toll-Like/metabolismoRESUMO
Although doxorubicin (Dox) is an effective antitumor antibiotic in the anthracycline class, it often induces the undesirable side effect of cardiomyopathy leading to congestive heart failure, which limits its clinical use. The primary goal of this study is to evaluate a reliable translational method for Dox-induced cardiotoxicity (CTX) screening, aiming to identify a high-risk population and to discover new strategies to predict and investigate this phenomenon. Early identification of the presence of iron deposits and genetic and environmental triggers that predispose individuals to increased risk of Dox-induced CTX (e.g., overexpression of Toll-like receptor 4 (TLR4)) will enable the early implementation of countermeasure therapy, which will improve the patient's chance of survival. Our cohort consisted of 25 consecutive patients with pathologically confirmed cancer undergoing Dox chemotherapy and 12 control patients. The following parameters were measured: serum TLR4 (baseline), serum transferrin (baseline and 6-week follow-up) and iron deposition (baseline and 6-week follow-up). The average number of gene expression units was 0.121 for TLR4 (range 0.051-0.801). We subsequently correlated serum TLR4 levels in our cohort with myocardial iron overload using the cardiac magnetic resonance (CMR) T2* technique, the ventricular function (% ejection fraction, %EF) and serum transferrin levels. There is a strong negative linear relationship between serum TLR4 and CMR T2* values (r = - 0.9106, ****P < 0.0001). There is also a linear correlation (either positive or negative) with EF and transferrin; no established relationship related to the sex of the patients was found. Patients with elevated serum TLR4 at baseline also exhibited an increase in serum transferrin levels and Dox-induced left ventricular dysfunction with a decreased EF (< 50%); this phenomenon was observed in 7 of 25 patients (28%) at the 6-week follow-up. There were no significant differences or correlations based on sex. We concluded that there is a direct relationship between Dox-induced CTX (indicated by elevated serum TLR4) and the times (ms) for T2* (decreases in which correspond to immediate and rapid iron overload).
Assuntos
Antibióticos Antineoplásicos/efeitos adversos , Cardiomiopatias/induzido quimicamente , Doxorrubicina/efeitos adversos , Neoplasias Hematológicas/tratamento farmacológico , Sobrecarga de Ferro/induzido quimicamente , Receptor 4 Toll-Like/metabolismo , Adolescente , Adulto , Idoso , Antibióticos Antineoplásicos/uso terapêutico , Cardiomiopatias/metabolismo , Cardiotoxicidade/etiologia , Cardiotoxicidade/metabolismo , Doxorrubicina/uso terapêutico , Feminino , Neoplasias Hematológicas/metabolismo , Humanos , Ferro/metabolismo , Sobrecarga de Ferro/metabolismo , Masculino , Pessoa de Meia-Idade , Medição de Risco , Receptor 4 Toll-Like/genética , Transferrina/metabolismo , Adulto JovemRESUMO
Uropathogenic Escherichia coli (UPEC) are common pathogens in urinary tract infections (UTIs), which show resistance to antibiotics. Therefore, there is a need for a vaccine to reduce susceptibility to the infection. In the present study, bioinformatics approaches were employed to predict the best B and T-cell epitopes of UPEC virulence proteins to develop a multiepitope vaccine candidate against UPEC. Then, the efficacy of the candidate was studied with and without Freund adjuvant. Using bioinformatics methods, 3 epitope-rich domains of IutA and FimH antigens were selected to construct the fusion. Molecular docking and Molecular dynamics (MD) simulation were employed to investigate in silico interaction between designed vaccine and Toll-like receptor 4 (TLR4). Our results showed that the levels of IgG and IgA antibodies were improved in the serum and mucosal samples of the vaccinated mice, and the IgG responses were maintained for at least 6 months. The fusion protein was also able to enhance the level of cytokines IFN.γ (Th1), IL.4 (Th2), and IL.17. In challenge experiments, all vaccine combinations showed high potency in the protection of the urinary tract even after 6 months post first injection. The present study indicates that the designed candidate is able to evoke strong protective responses which warrant further studies.
Assuntos
Infecções por Escherichia coli/prevenção & controle , Vacinas contra Escherichia coli/uso terapêutico , Infecções Urinárias/prevenção & controle , Escherichia coli Uropatogênica/imunologia , Animais , Simulação por Computador , Citocinas/metabolismo , Epitopos/imunologia , Infecções por Escherichia coli/imunologia , Vacinas contra Escherichia coli/imunologia , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Simulação de Acoplamento Molecular , Receptor 4 Toll-Like/metabolismo , Infecções Urinárias/imunologiaRESUMO
To explore the regulation mechanism of miR-26a-5p and connective tissue growth factor (CTGF) in lipopolysaccharide (LPS)-induced alveolar macrophages, which is a severe pneumonia cell model. MH-S cells were grouped into Normal group, Model group, negative control (NC) group, miR-26a-5p mimic group, oe-CTGF group, miR-26a-5p mimic + oe-CTGF group. The expression level of miR-26a-5p, CTGF and Toll-like receptor (TLR) signaling related molecules (TLR2, TLR4 and nuclear factor-κB p65) were detected by qRT-PCR and WB, respectively. The cell viability and apoptosis rate were detected by methyl thiazolyl tetrazolium (MTT) and flow cytometry, respectively. Compared with the Normal group, the expression level of miR-26a-5p was significantly decreased, while CTGF protein level was significantly increased in the Model group. Compared with the Model group, MH-S cells with miR-26a-5p overexpression showed enhanced cell viability, decreased apoptosis rate, declined expression level of TLR signaling related molecules and reduced level of tumor necrosis factor-α (TNF-α), interleukin (IL) 6 (IL-6) and IL-1ß, while those with CTGF overexpression had an opposite phenotype. In conclusion, miR-26a-5p can inhibit the expression of CTGF and mediate TLR signaling pathway to inhibit the cell apoptosis and reduce the expression of proinflammatory cytokines in alveolar macrophages which is a cell model of severe pneumonia.
Assuntos
Fator de Crescimento do Tecido Conjuntivo/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos Alveolares/efeitos dos fármacos , MicroRNAs/metabolismo , Pneumonia/metabolismo , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Fator de Crescimento do Tecido Conjuntivo/genética , Citocinas/metabolismo , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/patologia , Camundongos , MicroRNAs/genética , Pneumonia/genética , Pneumonia/patologia , Transdução de Sinais , Receptor 2 Toll-Like/genética , Receptor 4 Toll-Like/genética , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismoRESUMO
Obesity is commonly associated with immunometabolic dysfunctions. Activation of inflammatory macrophages through TLR4 (toll-like receptor 4) and the anti-inflammatory impact of exercise have been and are the new concerns among researchers. A new short-term combined high-intensity interval training was proposed in young sedentary overweight/obese females. All participants were allocated to one of two groups: the exercise group (EG) and the control group (CG), where the EG participated in a 2-week combined training and the CG continued its routine lifestyle. Gene expression levels of TLR4, NF-κB(nuclear factor κB), and IRF3 (interferon regulatory factor 3) were assessed by real-time PCR. Physiological, anthropometric, and biomedical metabolic factors were assessed. The between-group comparisons indicated a tendency to a decrease in NF-κB gene expression in the EG. The IRF3 levels were not significantly changed compared to CG and the levels before training. Fasting glucose levels and ß-cell function revealed a significant improvement in EG. These findings indicated that this protocol decreased meta-inflammation levels and improved insulin resistance independent of body composition changes. Consequently, combined training may be recommended as a therapeutic approach in metabolic diseases.
Assuntos
Perfilação da Expressão Gênica/métodos , Treinamento Intervalado de Alta Intensidade/métodos , Fator Regulador 3 de Interferon/metabolismo , NF-kappa B/metabolismo , Obesidade , Receptor 4 Toll-Like/metabolismo , Adulto , Feminino , Humanos , Resistência à Insulina/imunologia , Obesidade/imunologia , Obesidade/metabolismo , Obesidade/terapia , Avaliação de Resultados em Cuidados de SaúdeRESUMO
The Toll-like receptor 4 (TLR4) antagonists, (+)-naloxone and (+)-naltrexone, have been reported to decrease self-administration of opioids in rats and to reduce other preclinical indicators of abuse potential. However, under the self-administration conditions studied, the effects of TLR4 antagonists were not reinforcer selective, questioning the involvement of those receptors and their mediated inflammatory response specifically in opioid abuse. The objectives of the current study were to further characterize the reinforcer specificity of TLR4 antagonism in opioid self-administration and to explore its effects in a preclinical model of craving/relapse. The TLR4 antagonist (+)-naltrexone decreased responding in rats trained to self-administer the µ-opioid receptor agonist remifentanil, but with a potency that was not significantly different from that observed in another group of subjects in which responding was maintained by food reinforcement. Responding reinstated by heroin injection was decreased by (+)-naltrexone; however, a similar reduction was not reproduced with the administration of another TLR4 antagonist, lipopolysaccharide from Rhodobacter sphaeroides, administered into the NAcc shell. Thus, TLR4 antagonists lacked reinforcer selectivity in reducing opioid self-administration and were not uniformly effective in a model of craving/relapse, suggesting limitations on the development of (+)-naltrexone or TLR4 antagonists as treatments for opioid abuse.
Assuntos
Naltrexona/farmacologia , Transtornos Relacionados ao Uso de Opioides/fisiopatologia , Receptor 4 Toll-Like/metabolismo , Analgésicos Opioides/metabolismo , Analgésicos Opioides/farmacologia , Animais , Condicionamento Operante/efeitos dos fármacos , Heroína/administração & dosagem , Masculino , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Ratos , Ratos Sprague-Dawley , Reforço Psicológico , Autoadministração , Receptor 4 Toll-Like/antagonistas & inibidores , Receptor 4 Toll-Like/fisiologiaRESUMO
BACKGROUND: The exact aetiology of canine sino-nasal aspergillosis (SNA) is unknown. In man, dysfunction in innate immunity, particularly in the function of pattern recognition receptors, is implicated in the pathogenesis of inflammatory sino-nasal disease and in fungal diseases. Associations between single nucleotide polymorphisms (SNPs) in Toll-like receptors (TLRs) and these diseases have been identified. Similarly, in dogs SNPs in genes encoding TLRs may be important in the pathogenesis of SNA. The aims of the present study were (1) to identify the presence of non-synonymous SNPs in the coding regions of the TLR2, 4 and 9 genes in dogs suffering from SNA, and (2) to investigate the SNP genotypes in dogs with SNA compared with a control population. RESULTS: Direct sequencing of nine dogs of various breeds with SNA revealed two non-synonymous SNPs in the coding region of TLR2, eight in TLR4 and four in TLR9. These non-synonymous SNPs were further evaluated in a case-control study of affected Golden Retrievers, Labrador Retrievers, Rottweilers and Beaucerons. Genotyping was performed using a combination of allele-specific primers and hydrolysis probe assays in 31 dogs with SNA and 31 controls. No significant difference in minor allele frequency was identified between these groups, for all studied SNPs, in any of the four breeds. CONCLUSIONS: These findings do not support a role for non-synonymous SNPs in the TLR 2, 4 and 9 coding regions in the pathogenesis of canine SNA, but do not exclude a role for innate immunity in the pathogenesis of the disease.
Assuntos
Aspergilose/veterinária , Doenças do Cão/microbiologia , Rinite/veterinária , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Receptor Toll-Like 9/metabolismo , Animais , Aspergilose/metabolismo , Doenças do Cão/genética , Cães , Privacidade Genética , Genótipo , Polimorfismo de Nucleotídeo Único , Rinite/genética , Rinite/imunologia , Receptor 2 Toll-Like/genética , Receptor 4 Toll-Like/genética , Receptor Toll-Like 9/genéticaRESUMO
Human urinary disorders are generally studied in rodent models due to limitations of functional in vitro culture models of primary human urothelial cells (HUCs). Current HUC culture models are often derived from immortalized cancer cell lines, which likely have functional characteristics differ from healthy human urothelium. Here, we described a simple explant culture technique to generate HUCs and assessed their in vitro functions. Using transmission electron microscopy, we assessed morphology and heterogeneity of the generated HUCs and characterized their intercellular membrane structural proteins relative to ex vivo urothelium tissue. We demonstrated that our cultured HUCs are free of fibroblasts. They are also heterogeneous, containing cells characteristic of both immature basal cells and mature superficial urothelial cells. The cultured HUCs expressed muscarinic receptors (MR1 and MR2), carnitine acetyltransferase (CarAT), immunoregulatory cytokines IL7, IL15, and IL23, as well as the chemokine CCL20. HUCs also expressed epithelial cell-specific molecules essential for forming intercellular structures that maintain the functional capacity to form the physiological barrier of the human bladder urothelium. A subset of HUCs, identified by the high expression of CD44, expressed the Toll-like receptor 4 (TLR4) along with its co-receptor CD14. We demonstrated that HUCs express, at the mRNA level, both forms of the IL22 receptor, the membrane-associated (IL22RA1) and the secreted soluble (IL22RA2) forms; in turn, IL22 inhibited expression of MR1 and induced expression of CarAT and two antimicrobial peptides (S100A9 and lipocalin-2). While the cellular sources of IL22 have yet to be identified, the HUC cytokine and chemokine profiles support the concept that IL22-producing cells are present in the human bladder mucosa tissue and that IL22 plays a regulatory role in HUC functions. Thus, the described explant technique is clearly capable of generating functional HUCs suitable for the study of human urinary tract disorders, including interactions between urothelium and IL22-producing cells.
Assuntos
Acetilcolina/metabolismo , Calgranulina B/metabolismo , Interleucinas/farmacologia , Lipocalinas/metabolismo , Urotélio/metabolismo , Calgranulina B/genética , Células Cultivadas , Quimiocina CCL20/genética , Quimiocina CCL20/metabolismo , Humanos , Receptores de Hialuronatos/genética , Receptores de Hialuronatos/metabolismo , Lipocalinas/genética , Receptores de Lipopolissacarídeos/genética , Receptores de Lipopolissacarídeos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Interleucina/genética , Receptores de Interleucina/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Urotélio/efeitos dos fármacos , Urotélio/ultraestrutura , Interleucina 22RESUMO
BACKGROUND AND PURPOSE: Alternative use of molecular approaches is promising for improving nerve regeneration in surgical repair of neurotmesis. The purpose of this study was to determine the role of MR imaging in assessment of the enhanced nerve regeneration with toll-like receptor 4 signaling activation in surgical repair of neurotmesis. MATERIALS AND METHODS: Forty-eight healthy rats in which the sciatic nerve was surgically transected followed by immediate surgical coaptation received intraperitoneal injection of toll-like receptor 4 agonist lipopolysaccharide (n = 24, study group) or phosphate buffered saline (n = 24, control group) until postoperative day 7. Sequential T2 measurements and gadofluorine M-enhanced MR imaging and sciatic functional index were obtained over an 8-week follow-up period, with histologic assessments performed at regular intervals. T2 relaxation times and gadofluorine enhancement of the distal nerve stumps were measured and compared between nerves treated with lipopolysaccharide and those treated with phosphate buffered saline. RESULTS: Nerves treated with lipopolysaccharide injection achieved better functional recovery and showed more prominent gadofluorine enhancement and prolonged T2 values during the degenerative phase compared with nerves treated with phosphate buffered saline. T2 values in nerves treated with lipopolysaccharide showed a more rapid return to baseline level than did gadofluorine enhancement. Histology exhibited more macrophage recruitment, faster myelin debris clearance, and more pronounced nerve regeneration in nerves treated with toll-like receptor 4 activation. CONCLUSIONS: The enhanced nerve repair with toll-like receptor 4 activation in surgical repair of neurotmesis can be monitored by using gadofluorine M-enhanced MR imaging and T2 relaxation time measurements. T2 relaxation time seems more sensitive than gadofluorine M-enhanced MR imaging for detecting such improved nerve regeneration.
Assuntos
Imageamento por Ressonância Magnética/métodos , Regeneração Nervosa/fisiologia , Recuperação de Função Fisiológica/fisiologia , Receptor 4 Toll-Like/metabolismo , Animais , Axotomia , Fluorocarbonos , Masculino , Compostos Organometálicos/farmacologia , Compostos Radiofarmacêuticos/farmacologia , Ratos , Nervo Isquiático/lesõesRESUMO
House dust mite, Dermatophagoides pteronyssinus (Der p), is one of the major allergens responsible for allergic asthma. However, the putative receptors involved in the signalization of Der p to the innate immune cells are still poorly defined as well as the impact of their activation on the outcome of the allergen-induced cell response. We previously reported that the HDM activation of mouse alveolar macrophages (AM) involves the TLR4/CD14 cell surface receptor complex. Here using a TLR ligand screening essay, we demonstrate that HDM protein extract engages the TLR2, in addition to the TLR4, in engineered TLR-transfected HEK cells but also in the MH-S mouse alveolar macrophage cell line model. Moreover we found that the concomitant recruitment of the MH-S cell's TLR2 and TLR4 receptors by the HDM extract activates the MyD88-dependent signaling pathway and leads to the secretion of the NF-κB regulated pro-inflammatory factors NO and TNF-α. However unlike with the canonical TLR4 ligand (i.e. the bacterial LPS) mobilization of TLR4 by the HDM extract induces a reduced production of the IL-12 pro-inflammatory cytokine and fails to trigger the expression of the T-bet transcription factor. Finally we demonstrated that HDM extract down-regulates LPS induced IL-12 and T-bet expression through a TLR2 dependent mechanism. Therefore, we propose that the simultaneous engagement of the TLR2 and TLR4 receptors by the HDM extract results in a cross regulated original activation pattern of the AM which may contribute to the Th2 polarization of the allergen-induced immune response. The deciphering of these cross-regulation networks is of prime importance to open the way for original therapeutic strategies taking advantage of these receptors and their associated signaling pathways to treat allergic asthma.
Assuntos
Antígenos de Dermatophagoides/imunologia , Imunidade Inata , Macrófagos Alveolares/imunologia , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Células HEK293 , Humanos , Interleucina-12/biossíntese , Ligantes , Camundongos , Óxido Nítrico/biossíntese , Proteínas com Domínio T/metabolismo , Células Th1/imunologia , Células Th1/metabolismo , Receptor 2 Toll-Like/agonistas , Receptor 4 Toll-Like/agonistas , Fator de Necrose Tumoral alfa/biossínteseRESUMO
Single-particle tracking (SPT) is widely used to study processes from membrane receptor organization to the dynamics of RNAs in living cells. While single-dye labeling strategies have the benefit of being minimally invasive, this comes at the expense of data quality; typically a data set of short trajectories is obtained and analyzed by means of the mean square displacements (MSD) or the distribution of the particles' displacements in a set time interval (jump distance, JD). To evaluate the applicability of both approaches, a quantitative comparison of both methods under typically encountered experimental conditions is necessary. Here we use Monte Carlo simulations to systematically compare the accuracy of diffusion coefficients (D-values) obtained for three cases: one population of diffusing species, two populations with different D-values, and a population switching between two D-values. For the first case we find that the MSD gives more or equally accurate results than the JD analysis (relative errors of D-values <6%). If two diffusing species are present or a particle undergoes a motion change, the JD analysis successfully distinguishes both species (relative error <5%). Finally we apply the JD analysis to investigate the motion of endogenous LPS receptors in live macrophages before and after treatment with methyl-ß-cyclodextrin and latrunculin B.
Assuntos
Membrana Celular/metabolismo , Corantes/metabolismo , Método de Monte Carlo , Algoritmos , Animais , Receptores de Lipopolissacarídeos/metabolismo , Lipopolissacarídeos/metabolismo , Camundongos , Técnicas de Sonda Molecular , Receptor 4 Toll-Like/metabolismoRESUMO
Angelica sinensis (Oliv) Diels, a traditional oriental herbal medicine, is known to have immunostimulatory and antitumor effects. In this paper, four hydrosoluble fractions were obtained and purified from A. sinensis including: Angelica polysaccharide, oligosaccharides (Angelica oligosaccharide and Angelica sucrose) and Angelica total amino acid, named APS, AOS, AS, and TAA, respectively. Moreover, the immunomodulatory activity of these four fractions on murine peritoneal macrophages were assessed and compared from various aspects including cell proliferation, phagocytic activity, nitric oxide (NO) and hydrogen peroxide (H(2)O(2)) release, induced nitric oxide synthetase (iNOS) and lysozyme (LZM) activity, intracellular adhesion molecule-1 (ICAM-1) expression on cell surface and Toll-like receptor 4 (TLR4) gene expression. Although APS exhibited the most obvious growth facilitative activity, AOS did better in activation of H(2)O(2) release; TAA exerted the best activation of phagocytic activity, production of NO and ICAM-1 expression. Furthermore, we found that the action mode of the four fractions was similar to that of LPS and the mechanism may be related to the upregulation of TLR4 mRNA. These results demonstrated that oligosaccharide and amino acid fractions, as well as polysaccharide fraction of Radix A. sinensis, could serve as immunomodulator and TLR4 as one of the immune receptors may play important role for this action.
Assuntos
Adjuvantes Imunológicos/farmacologia , Angelica sinensis/química , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/imunologia , Adjuvantes Imunológicos/química , Animais , Proliferação de Células/efeitos dos fármacos , Feminino , Peróxido de Hidrogênio/metabolismo , Técnicas In Vitro , Molécula 1 de Adesão Intercelular/biossíntese , Lipopolissacarídeos/farmacologia , Macrófagos Peritoneais/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Muramidase/análise , Muramidase/metabolismo , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo II/análise , Óxido Nítrico Sintase Tipo II/metabolismo , Fagocitose/efeitos dos fármacos , Extratos Vegetais/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Receptor 4 Toll-Like/análise , Receptor 4 Toll-Like/metabolismoRESUMO
AIM: To study protective activity of recombinant construction of heat-shock protein with lypopolysaccharide (rcHSP-LPS) as well as its variants (with destroyed protein or bounded LPS) against Salmonella typhimurium. It was also planned to study the ability of rcHSP-LPS to interact with toll-like receptors (TLRs) expressed on continuous cell lines. MATERIALS AND METHODS: One of the following preparations was administered to outbred mice: rcHSP-LPS; rcHSP-LPS treated by polymyxin B (PMB) for bounding of LPS - rc(HSP-LPS)PMB; rcHSP-LPS in which protein was treated by boiling during 30 min--rc (HSP-LPS)B; LPS (E. coli K-235); polymyxin B (PMB). Twenty-four hours after single or last administration of rcHSP-LPS, each mice was intraperitoneally inoculated with 63 LD50 of S. typhimurium 415 contained in 0.5 ml of physiologic solution. Antibody titer to LPS of Salmonella typhimurium was measured by immunoenzyme assay. RESULTS: It was demonstrated that rcHSP-LPS administered 24 hours before inoculation induced resistance to S. typhimurium infection. Protection formed after 3 injections of rcHSP-LPS with 10 mcg in each or single injection with 100 mcg/mouse. Forty to eighty percent of immunized mice survived after challenge while 90% of control animals died. Destroy of the HSP by boiling of the construction led to loss of protective effect. Bounding of LPS by PMB did not lead to loss of protective properties of the construction but they expressed only after its multiple administration with 10 mcg per mouse. LPS of E. coli in dose 0.0266 mcg per mouse as well as PMB did not influence the course of S. typhimurium infection in mice. CONCLUSION: It was shown that rcHSP-LPS effectively protects mice from S. typhimurium infection by activating innate immunity; one of the possible mechanisms for such protection determined by interaction with TLRs 2 and 4 was considered. Other studies are needed in order to elucidate other mechanisms of innate immunity, which can be activated by rcHSP-LPS.
Assuntos
Vacinas Bacterianas/imunologia , Proteínas de Choque Térmico HSP70/imunologia , Lipopolissacarídeos/imunologia , Infecções por Salmonella/prevenção & controle , Salmonella typhimurium/imunologia , Animais , Vacinas Bacterianas/administração & dosagem , Linhagem Celular , Relação Dose-Resposta Imunológica , Proteínas de Choque Térmico HSP70/administração & dosagem , Humanos , Injeções Intraperitoneais , Lipopolissacarídeos/administração & dosagem , Camundongos , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/imunologia , Infecções por Salmonella/sangue , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologiaRESUMO
Protracted bacterial bronchitis (PBB) is a common cause of paediatric chronic moist cough. PBB is defined as the presence of isolated chronic moist cough which resolves with antibiotic therapy within 2 weeks and an absence of pointers suggesting alternative diagnoses. Our aim was to describe the clinical profile and examine the airway cellularity and likely promoters of neutrophilic inflammation in the bronchoalveolar lavage (BAL) of children with PBB compared with chronic cough due to other causes and controls. We explored the innate immune signaling receptors, toll-like receptors (TLR)-2 and TLR-4, as well as relevant effector molecules. A cross-sectional comparison was made of 100 children median age 2.58 years (with either PBB, coughing due to another cause or no cough controls) who underwent flexible bronchoscopy with lavage. BAL was evaluated for airway cytology, microbiology, inflammatory mediators interleukin 8 (IL-8) and active matrix metalloproteinase 9 (MMP-9) and TLR-2 and TLR-4 messenger RNA (mRNA) expression. Children with PBB had marked airway neutrophilia and increased median cytokine levels when compared to those with cough that resolved naturally and no cough controls: IL-8 0.67 versus 0.07 and 0.06 ng/ml (P < 0.005) and active MMP-9 7.25 versus 1.35 and 0.38 ng/ml (P < 0.005). The values for TLR-2 and TLR-4 mRNA expression were significantly elevated in children with PBB when compared to the control group. PBB is a paediatric condition which presents with chronic moist cough and its airway profile is characterized by intense neutrophilic airway inflammation with marked inflammatory mediator response and evidence of innate immune activation.
Assuntos
Bronquite/imunologia , Líquido da Lavagem Broncoalveolar/imunologia , Neutrófilos/metabolismo , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Bronquite/microbiologia , Líquido da Lavagem Broncoalveolar/citologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Tosse/imunologia , Feminino , Humanos , Lactente , Interleucina-8/análise , Leucocitose/imunologia , Leucocitose/metabolismo , Masculino , Metaloproteinase 9 da Matriz/análise , Neutrófilos/imunologia , RNA Mensageiro/metabolismo , Receptor 2 Toll-Like/genética , Receptor 4 Toll-Like/genéticaRESUMO
OBJECTIVE: Unfavorable socioeconomic status (SES) circumstances early in life are associated with heightened vulnerability to respiratory and cardiovascular diseases in adulthood. However, little is known about mechanisms underlying this phenomenon. METHODS: This study examined whether early-life SES predicts future activity of two genes involved in regulating inflammation. An ethnically diverse cohort of 136 adolescent females was enrolled in the study. SES was measured by home ownership. The messenger ribonucleic acid (mRNA) for glucocorticoid receptor (GR) and toll-like receptor 4 (TLR4) was quantified in peripheral blood leukocytes using real-time reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: Three findings emerged: a) Years 2 to 3 of life were a critical period: the participants whose families owned homes during these childhood years showed higher GR mRNA and lower TLR4 mRNA during adolescence, a profile that suggests better regulation of inflammatory responses. b) These effects were not mediated through current economic circumstances, life stress, or health practices. C) Changes in SES during later years were unable to "undo" these effects. CONCLUSIONS: These findings suggest that unfavorable SES circumstances in the early years of life presage the expression of a proinflammatory phenotype in adolescence. To the extent that this proclivity toward inflammation persists over one's lifespan it could explain the heightened incidence of respiratory and cardiovascular disease in low SES populations.