RESUMO
Among all cancers, lung cancer is the one with the highest mortality rate, and it also has limited therapeutics. Antitumor agents based on medicinal plants have gained importance as a source of bioactive substances. Tagetes erecta is a plant of great cultural value, and recent reports have suggested its cytotoxic effects in tumor cells. Our objective was to evaluate the antitumor activity of Tagetes erecta extract in a lung carcinoma model. Hydroalcoholic extracts were obtained from fresh flowers and leaves of T. erecta; both extracts did not exert toxicity on Artemia salina. We observed cytotoxic effects induced by the floral extract in Lewis lung carcinoma (LLC) and breast tumor cell line (MCF7), but not by the leaf extract. In vivo, a xenograft lung carcinoma model was performed with LLC cells implanted on C57BL/6 mice, which showed that the floral extract reduced tumor growth and improved the effect of etoposide. Microscopic analysis of tumors showed a reduction in mitoses and an increase in necrotic areas with the extract and the etoposide. The main phytochemical compounds found are 2,3-dihydro-benzofuran, octadecanoic acid, benzenacetic acid, oleic acid, linoleic acid, and acetic acid. We conclude that the hydroalcoholic extract of T. erecta flowers has cytotoxic effects in lung carcinoma cells and enhances the effect of etoposide.
Assuntos
Antineoplásicos , Carcinoma , Neoplasias Pulmonares , Tagetes , Humanos , Animais , Camundongos , Tagetes/química , Neoplasias Pulmonares/tratamento farmacológico , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Etoposídeo , Camundongos Endogâmicos C57BL , Antineoplásicos/farmacologia , PulmãoRESUMO
Structure-activity relationship (SAR) studies allow the evaluation of the relationship between structural chemical changes and biological activity. Fluoroquinolones have chemical characteristics that allow their structure to be modified and new analogs with different therapeutic properties to be generated. The objective of this research is to identify and select the C-7 heterocycle fluoroquinolone analog (FQH 1-5) with antibacterial activity similar to the reference fluoroquinolone through in vitro, in silico, and in vivo evaluations. First, SAR analysis was conducted on the FQH 1-5, using an in vitro antimicrobial sensibility model in order to select the best compound. Then, an in silico model mechanism of action analysis was carried out by molecular docking. The non-bacterial cell cytotoxicity was evaluated, and finally, the antimicrobial potential was determined by an in vivo model of topical infection in mice. The results showed antimicrobial differences between the FQH 1-5 and Gram-positive and Gram-negative bacteria, identifying the 7-benzimidazol-1-yl-fluoroquinolone (FQH-2) as the most active against S. aureus. Suggesting the same mechanism of action as the other fluoroquinolones; no cytotoxic effects on non-bacterial cells were found. FQH-2 was demonstrated to decrease the amount of bacteria in infected wound tissue.
Assuntos
Antibacterianos , Anti-Infecciosos , Animais , Camundongos , Antibacterianos/farmacologia , Fluoroquinolonas/farmacologia , Simulação de Acoplamento Molecular , Staphylococcus aureus , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Relação Estrutura-AtividadeRESUMO
The aim of the present work was to evaluate MTX treatment (0.1, 1 and 10 µg mL-1) in vitro in order to characterize its effects on cell proliferation alterations in cell cycle of HaCaT keratinocytes and wound healing in a Skh1 mice treated with MTX (low doses 30 mg kg-1, high doses 200 mg kg-1 and repeated doses at 1.5 mg kg-1). We analyzed the cytotoxic effect of methotrexate by a resazurin assay. The effects in the proliferation, cell cycle and apoptosis of HaCaT cells were analyzed by flow cytometry. The effects of MTX on wound healing in vivo were also analyzed. A trend toward reduction in the resazurin assay was found (p > 0.05). Reduced proliferation was also identified in a clonogenic assay and a CFSE assay (p < 0.05) due to the MTX treatment. A reduction in the G2/M and S phases was observed accompanied by apoptosis induction with increased sub G0 phase and annexin V FITC staining. Effect of MTX was evidenced in vivo on the wound closure process after day 10 (p < 0.05) with alterations in tissue architecture and remodeling. There is a marked effect of MTX on wound healing in vivo in Skh1 mice with implications for long-term therapy and surgical interventions.
Assuntos
Proliferação de Células/efeitos dos fármacos , Queratinócitos/efeitos dos fármacos , Metotrexato/farmacologia , Cicatrização/efeitos dos fármacos , Análise de Variância , Animais , Apoptose/efeitos dos fármacos , Modelos Animais de Doenças , Camundongos , Estatísticas não ParamétricasRESUMO
Hemoglobin S is an abnormal protein that induces morphological changes in erythrocyte in low-oxygen conditions. In Mexico, it is reported that up to 13.7% of the population with mutation in one allele are considered asymptomatic (sickle cell trait). The sickle cell trait and diabetes mellitus are conditions that occur together in more than one million patients worldwide. Both diseases possibly produce microvascular changes in retinopathy and acute chest syndrome. The aim of this study was to evaluate the induction of sickle cells in samples of diabetic patients with sickle cell trait to identify altered red cell parameters. We obtained samples of diabetic patients to determine hemoglobin A1c and S; furthermore, red blood cell biometrics data were analyzed. We found that older men with diabetes were susceptible to generate sickle cells and this correlated with reduced red blood cell count and an increase in media cell volume. In samples of women diabetes, there were no differences. We conclude that samples from patients with sickle cell trait and diabetes can cause sickle cells with high frequency in men, with lower red blood cells count and increased mean corpuscular volume as susceptibility parameters.
Assuntos
Diabetes Mellitus Tipo 2/sangue , Hemoglobinas Glicadas/análise , Hemoglobina Falciforme/análise , Traço Falciforme/sangue , Tamanho Celular , Contagem de Eritrócitos , Feminino , Humanos , Masculino , México , Fatores SexuaisRESUMO
It is estimated that there are approximately eight million new cases of active tuberculosis (TB) worldwide annually. There is only 1 vaccine available for prevention: bacillus Calmette-Guérin (BCG). This has variable efficacy and is only protective for certain extrapulmonary TB cases in children, therefore new strategies for the creation of novel vaccines have emerged. One of the promising approaches is the DNA vaccine, used as a direct vaccination or as a prime-boost vaccine. This review describes the experimental data obtained during the design of DNA vaccines for TB.
Assuntos
Vacinas contra a Tuberculose/administração & dosagem , Tuberculose/prevenção & controle , Vacinas de DNA/administração & dosagem , Animais , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Humanos , Tuberculose/imunologia , Vacinas contra a Tuberculose/química , Vacinas contra a Tuberculose/genética , Vacinas contra a Tuberculose/imunologia , Vacinas de DNA/química , Vacinas de DNA/genética , Vacinas de DNA/imunologiaRESUMO
It has been reported that patients with progressive tuberculosis (TB) express abundant amounts of the antimicrobial peptides (AMPs) cathelicidin (LL-37) and human neutrophil peptide-1 (HNP-1) in circulating cells, whereas latent TB infected donors showed no differences when compared with purified protein derivative (PPD) and QuantiFERON®-TB Gold (QFT)-healthy individuals. The aim of this study was to determine whether LL-37 and HNP-1 production correlates with higher tuberculin skin test (TST) and QFT values in TB household contacts. Twenty-six TB household contact individuals between 26-58 years old TST and QFT positive with at last two years of latent TB infection were recruited. AMPs production by polymorphonuclear cells was determined by flow cytometry and correlation between TST and QFT values was analysed. Our results showed that there is a positive correlation between levels of HNP-1 and LL-37 production with reactivity to TST and/or QFT levels. This preliminary study suggests the potential use of the expression levels of these peptides as biomarkers for progression in latent infected individuals.
Assuntos
Células Sanguíneas/química , Catelicidinas/sangue , Tuberculose Latente/diagnóstico , Mycobacterium tuberculosis/imunologia , alfa-Defensinas/sangue , Adulto , Peptídeos Catiônicos Antimicrobianos , Biomarcadores/sangue , Catelicidinas/metabolismo , Busca de Comunicante , Progressão da Doença , Feminino , Expressão Gênica , Humanos , Testes de Liberação de Interferon-gama/métodos , Tuberculose Latente/metabolismo , Masculino , Pessoa de Meia-Idade , Neutrófilos/metabolismo , Teste Tuberculínico/métodosRESUMO
Inflammation is a physiological process, which eliminates pathogens and induces repair of damaged tissue. This process is controlled by negative feedback mechanisms, but if the inflammation persists, it generates a deleterious autoimmune process or can to contribute with diseases such as obesity or cancer. The inflammation resolution involves mechanisms such as decrease of proliferation and maturation of immune cells, phagocytosis and apoptosis of immune cells, and decrease of proinflammatory mediators. Therefore, is relevant to study the physiological effects of specific receptors that participate in inflammation resolution and the design of specific agonists as conventional anti-inflammatory therapeutics, without dramatic collateral effects. In this review, we study some mechanisms associated with inflammation inhibition, particularly the transduction of receptors for ligands with anti-inflammatory effects and that are relevant for their potential therapeutic.
Assuntos
Anti-Inflamatórios/farmacologia , Inflamação/fisiopatologia , Transdução de Sinais/fisiologia , Animais , Apoptose/fisiologia , Desenho de Fármacos , Humanos , Inflamação/complicações , Inflamação/tratamento farmacológico , Mediadores da Inflamação/metabolismo , Fagocitose/fisiologiaRESUMO
HIV (human immunodeficiency virus) infection is today a very important health issue worldwide, which demands new ways and strategies for its prevention and treatment. Several studies on the innate immunity against HIV infection have shown that antimicrobial peptides are associated with increased resistance to infection. In the present review, we briefly summarize the major characteristics of antimicrobial peptides from human and several species of plants, amphibians, insects and other animal species that have significant potential to be used as therapeutic or prophylactic agents. The mechanisms of infection inhibition and viral replication blockade are also described in the context of the biology of infection.
Assuntos
Fármacos Anti-HIV/uso terapêutico , Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Infecções por HIV/tratamento farmacológico , Animais , Fármacos Anti-HIV/isolamento & purificação , Fármacos Anti-HIV/farmacologia , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Peptídeos Catiônicos Antimicrobianos/farmacologia , Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos , HIV/efeitos dos fármacos , Humanos , Invertebrados/química , Plantas/química , Especificidade da Espécie , Vertebrados/metabolismo , Replicação Viral/efeitos dos fármacosRESUMO
Diabetes is a chronic disease characterized by marked alterations in the metabolism of glucose and by high concentrations of glucose in the blood due to a decreased insulin production or resistance to the action of this hormone in peripheral tissues. The International Diabetes Federation estimates a global incidence of diabetes of about 10% in the adult population (20 - 79 years old), some 430 million cases reported worldwide in 2018. It is well documented that people with diabetes have a higher susceptibility to infectious diseases and therefore show higher morbidity and mortality compared to the non-diabetic population. Given that the innate immune response plays a fundamental role in protecting against invading pathogens through a myriad of humoral and cellular mechanisms, the present work makes a comprehensive review of the innate immune alterations in patients with type 2 diabetes mellitus (T2D) as well as a brief description of the molecular events leading or associated to such conditions. We show that in these patients a compromised innate immune response increases susceptibility to infections.
Assuntos
Diabetes Mellitus Tipo 2/complicações , Imunidade Inata , Infecções/patologia , Animais , Diabetes Mellitus Tipo 2/imunologia , Humanos , Infecções/etiologiaRESUMO
Normal cells are hijacked by cancer cells forming together heterogeneous tumor masses immersed in aberrant communication circuits that facilitate tumor growth and dissemination. Besides the well characterized angiogenic effect of some tumor-derived factors; others, such as BDNF, recruit peripheral nerves and leukocytes. The neurogenic switch, activated by tumor-derived neurotrophins and extracellular vesicles, attracts adjacent peripheral fibers (autonomic/sensorial) and neural progenitor cells. Strikingly, tumor-associated nerve fibers can guide cancer cell dissemination. Moreover, IL-1ß, CCL2, PGE2, among other chemotactic factors, attract natural immunosuppressive cells, including T regulatory (Tregs), myeloid-derived suppressor cells (MDSCs), and M2 macrophages, to the tumor microenvironment. These leukocytes further exacerbate the aberrant communication circuit releasing factors with neurogenic effect. Furthermore, cancer cells directly evade immune surveillance and the antitumoral actions of natural killer cells by activating immunosuppressive mechanisms elicited by heterophilic complexes, joining cancer and immune cells, formed by PD-L1/PD1 and CD80/CTLA-4 plasma membrane proteins. Altogether, nervous and immune cells, together with fibroblasts, endothelial, and bone-marrow-derived cells, promote tumor growth and enhance the metastatic properties of cancer cells. Inspired by the demonstrated, but restricted, power of anti-angiogenic and immune cell-based therapies, preclinical studies are focusing on strategies aimed to inhibit tumor-induced neurogenesis. Here we discuss the potential of anti-neurogenesis and, considering the interplay between nervous and immune systems, we also focus on anti-immunosuppression-based therapies. Small molecules, antibodies and immune cells are being considered as therapeutic agents, aimed to prevent cancer cell communication with neurons and leukocytes, targeting chemotactic and neurotransmitter signaling pathways linked to perineural invasion and metastasis.
Assuntos
Terapia de Alvo Molecular , Neoplasias/genética , Neurogênese/genética , Evasão Tumoral/genética , Comunicação Celular/genética , Humanos , Células Matadoras Naturais/imunologia , Neoplasias/complicações , Neoplasias/terapia , Evasão Tumoral/imunologiaRESUMO
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the coronavirus disease (COVID-19), a highly contagious infectious disease that has caused many deaths worldwide. Despite global efforts, it continues to cause great losses, and leaving multiple unknowns that we must resolve in order to face the pandemic more effectively. One of the questions that has arisen recently is what happens, after recovering from COVID-19. For this reason, the objective of this study is to identify the risk of presenting persistent symptoms in recovered from COVID-19. This case-control study was conducted in one state of Mexico. Initially the data were obtained from the participants, through a questionnaire about symptoms that they had at the moment of the interview. Initially were captured the collected data, to make a dataset. After the pre-processed using the R project tool to eliminate outliers or missing data. Obtained finally a total of 219 participants, 141 recovered and 78 controls. It was used confidence level of 90% and a margin of error of 7%. From results it was obtained that all symptoms have an associated risk in those recovered. The relative risk of the selected symptoms in the recovered patients goes from 3 to 22 times, being infinite for the case of dyspnea, due to the fact that there is no control that presents this symptom at the moment of the interview, followed by the nausea and the anosmia with a RR of 8.5. Therefore, public health strategies must be rethought, to treat or rehabilitate, avoiding chronic problems in patients recovered from COVID-19.
Assuntos
COVID-19/diagnóstico , Adulto , COVID-19/fisiopatologia , Estudos de Casos e Controles , Doença Crônica , Feminino , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Inquéritos e QuestionáriosRESUMO
Skin insult and damage start a complex healing process that involves a myriad of coordinated reactions at both the cellular and molecular level occurring simultaneously. These processes can be divided into that of cell migration and tissue remodeling of the wound. In addition, it is well known that deep wounds that derive from surgical procedures need a multidisciplinary approach to have a successful wound healing process. Recently, there has been a renowned interest in the identification of active compounds derived from ornamental, edible, and wild plants being used in the cosmetic and skin product industry. Recent reports suggest that active components of several plants such as Propolis and Aloe vera could be used to induce the process of wound healing and tissue regeneration and reducing therefore the time to complete wound closure. Other plant species such as Achillea millefolium or Salvia officinalis have anti-inflammatory properties and promote cellular proliferation contributing to faster tissue regeneration. It has been described that Malva sylvestris influences the formation of fibrosis-free granulation tissue in the skin. Recent observations suggest that Casearia sylvestris induces the angiogenic process. These effects have been evaluated in cell lines, different animal models, and some in randomized clinical trials. In this review we summarize the evidence of plant extracts and their active components (when known) in the acceleration of the wound closure process and tissue repair.
Assuntos
Extratos Vegetais/administração & dosagem , Plantas Medicinais/química , Cicatrização/efeitos dos fármacos , Ferimentos e Lesões/tratamento farmacológico , Animais , Humanos , Extratos Vegetais/química , Ferimentos e Lesões/fisiopatologiaRESUMO
Chronic exposure to arsenic (As), whether directly through the consumption of contaminated drinking water or indirectly through the daily intake of As-contaminated food, is a health threat for more than 150 million people worldwide. Epidemiological studies found an association between chronic consumption of As and several pathologies, the most common being cancer-related disorders. However, As consumption has also been associated with metabolic disorders that could lead to diverse pathologies, such as type 2 diabetes mellitus, nonalcoholic fatty liver disease, and obesity. Here, we used ultra-performance liquid chromatography (UPLC) coupled to electrospray ionization/quadrupole time-of-flight mass spectrometry (ESI-QToF) to assess the effect of chronic intergenerational As exposure on the lipid metabolism profiles of serum from 4-month-old Wistar rats exposed to As prenatally and also during early life in drinking water (3 ppm). Significant differences in the levels of certain identified lysophospholipids, phosphatidylcholines, and triglycerides were found between the exposed rats and the control groups, as well as between the sexes. Significantly increased lipid oxidation determined by the malondialdehyde (MDA) method was found in exposed rats compared with controls. Chronic intergenerational As exposure alters the rat lipidome, increases lipid oxidation, and dysregulates metabolic pathways, the factors associated with the chronic inflammation present in different diseases associated with chronic exposure to As (i.e., keratosis, Bowen's disease, and kidney, liver, bladder, and lung cancer).
Assuntos
Arsênio/toxicidade , Água Potável/efeitos adversos , Metabolismo dos Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Lisofosfolipídeos/sangue , Animais , Cromatografia Líquida de Alta Pressão , Água Potável/química , Humanos , Redes e Vias Metabólicas/efeitos dos fármacos , Ratos , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em TandemRESUMO
Type 2 diabetes mellitus (DM2) is strongly associated with other comorbidities such as obesity, atherosclerosis, and hypertension. Obesity is associated with sustained low-grade inflammatory response due to the production of proinflammatory cytokines. This inflammatory process promotes the differentiation of some myeloid cells, including myeloid-derived suppressor cells (MDSCs). In this study, two groups of individuals were included: DM2 patients and non-DM2 individuals with similar characteristics. Immunolabeling of CD15+ CD14- and CD33+ HLA-DR-/low was performed from whole peripheral blood, and samples were analyzed by flow cytometry, and frequencies of MDSCs and the relationship of these with clinical variables, cytokine profile (measured by cytometric bead array), and anthropometric variables were analyzed. The frequency of CD33+ HLA-DR-/low MDSCs (that produce IL-10 and TGF-ß, according to an intracellular detection) is higher in patients with DM2 (P < 0.05), and there is a positive correlation between the frequency of CD15+ CD14- and CD33+ HLA-DR-/low MDSC phenotypes. DM2 patients have an increased concentration of serum IL-5 (P < 0.05). Also, a negative correlation between the frequency of CD15+ CD14- MDSCs and LDL cholesterol was found. Our group of DM2 patients have an increased frequency of mononuclear MDSC CD33+ HLA-DR-/low that produce TGF-ß and IL-10. These cytokines have been associated with immune modulation and reduced T cell responses. DM2 and non-DM2 subjects show a similar cytokine profile, but the DM2 patients have an increased concentration of IL-5.
Assuntos
Diabetes Mellitus Tipo 2/imunologia , Hipertensão/imunologia , Células Supressoras Mieloides/imunologia , Adulto , Feminino , Antígenos HLA-DR/análise , Humanos , Interleucina-10/biossíntese , Interleucina-5/sangue , Masculino , Pessoa de Meia-Idade , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico/análise , Fator de Crescimento Transformador beta/biossínteseRESUMO
BACKGROUND: Several epidemiological studies in diabetic patients have demonstrated a protective effect of metformin to the development of several types of cancer. The underlying mechanisms of such phenomenon is related to the effect of metformin on cell proliferation among which, mTOR, AMPK and other targets have been identified. However, little is known about the role that metformin treatment have on other cell types such as keratinocytes and whether exposure to metformin of these cells might have serious repercussions in wound healing delay and in the development of complications in diabetic patients with foot ulcers or in their exacerbation. MATERIAL AND METHODS: HaCaT Cells were exposed to various concentrations of metformin and cell viability was evaluated by a Resazurin assay; Proliferation was also evaluated with a colony formation assay and with CFSE dilution assay by flow cytometry. Cell cycle was also evaluated by flow cytometry by PI staining. An animal model of wound healing was used to evaluate the effect of metformin in wound closure. Also, an analysis of patients receiving metformin treatment was performed to determine the effect of metformin treatment on the outcome and wound area. Statistical analysis was performed on SPSS v. 18 and GraphPad software v.5. RESULTS: Metformin treatment significantly reduces cell proliferation; colony formation and alterations of the cell cycle are observed also in the metformin treated cells, particularly in the S phase. There is a significant increase in the area of the wound of the metformin treated animals at different time points (P<0.05). There is also a significant increase in the size and wound area of the patients with diabetic foot ulcers at the time of hospitalization. A protective effect of metformin was observed for amputation, probably associated with the anti inflammatory effects reported of metformin. CONCLUSIONS: Metformin treatment reduces cell proliferation and reduces wound healing in an animal model and affects clinical outcomes in diabetic foot ulcer patients. Chronic use of this drug should be further investigated to provide evidence of their security in association with DFU.
Assuntos
Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Pé Diabético , Metformina/administração & dosagem , Cicatrização/efeitos dos fármacos , Adulto , Idoso , Animais , Linhagem Celular , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Pé Diabético/tratamento farmacológico , Pé Diabético/metabolismo , Pé Diabético/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ratos , Ratos WistarRESUMO
[This corrects the article DOI: 10.1371/journal.pone.0150900.].
RESUMO
The World Health Organization (WHO) has estimated that there are about 8 million new cases annually of active Tuberculosis (TB). Despite its irregular effectiveness (0-89%), the Bacillus Calmette-Guérin) BCG is the only vaccine available worldwide for prevention of TB; thus, the design is important of novel and more efficient vaccination strategies. Considering that ß-defensin-2 is an antimicrobial peptide that induces dendritic cell maturation through the TLR-4 receptor and that both ESAT-6 and Ag85B are immunodominant mycobacterial antigens and efficient activators of the protective immune response, we constructed two DNA vaccines by the fusion of the gene encoding ß-defensin-2 and antigens ESAT6 (pDE) and 85B (pDA). After confirming efficient local antigen expression that induced high and stable Interferon gamma (IFN-γ) production in intramuscular (i.m.) vaccinated Balb/c mice, groups of mice were vaccinated with DNA vaccines in a prime-boost regimen with BCG and with BCG alone, and 2 months later were challenged with the mild virulence reference strain H37Rv and the highly virulent clinical isolate LAM 5186. The level of protection was evaluated by survival, lung bacilli burdens, and extension of tissue damage (pneumonia). Vaccination with both DNA vaccines showed similar protection to that of BCG. After the challenge with the highly virulent Mycobacterium tuberculosis strain, animals that were prime-boosted with BCG and then boosted with both DNA vaccines showed significant higher survival and less tissue damage than mice vaccinated only with BCG. These results suggest that improvement of BCG vaccination, such as the prime-boost DNA vaccine, represents a more efficient vaccination scheme against TB.
Assuntos
Aciltransferases , Antígenos de Bactérias , Vacina BCG , Proteínas de Bactérias , Tuberculose Pulmonar/prevenção & controle , Vacinas de DNA , beta-Defensinas , Aciltransferases/genética , Animais , Antígenos de Bactérias/genética , Vacina BCG/administração & dosagem , Vacina BCG/imunologia , Proteínas de Bactérias/genética , Modelos Animais de Doenças , Imunização Secundária , Interferon gama/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium tuberculosis/patogenicidade , Células Th1/imunologia , Vacinas contra a Tuberculose/administração & dosagem , Vacinas contra a Tuberculose/imunologia , Tuberculose Pulmonar/imunologia , Tuberculose Pulmonar/microbiologia , Vacinação , Vacinas de DNA/administração & dosagem , Vacinas de DNA/imunologia , beta-Defensinas/genética , beta-Defensinas/imunologiaRESUMO
BACKGROUND AND AIMS: Defensins are low molecular weight antimicrobial and immunomodulatory peptides. Their participation against Mycobacterium tuberculosis (MTb) infection has been scarcely studied. METHODS: We describe the kinetics of murine ß-defensin 2 (mBD-2) expression by quantitative real-time PCR and cellular location by immunohistochemistry in murine models of progressive pulmonary tuberculosis and latent infection. RESULTS: During progressive disease, mBD2 gene expression raised its peak at 14 days postinfection, whereas in latent infection it was at 90 days. In both models, mBD-2 immunostaining was essentially located in cells with dendritic morphology located near mediastinal lymph nodes, which correlated with the previous reported highest expression of cell-mediated protected immunity in both models. CONCLUSIONS: These results suggest that mBD-2 may play a role in the control of bacilli growth by contributing to establish a Th1 response, being a link between innate and adaptative immunity. These data may be used for the development of new vaccine approaches.
Assuntos
Células Dendríticas/metabolismo , Pulmão/imunologia , Células Th1/imunologia , Vacinas contra a Tuberculose , Tuberculose Pulmonar/metabolismo , beta-Defensinas/fisiologia , Imunidade Adaptativa , Animais , Cruzamentos Genéticos , Células Dendríticas/imunologia , Progressão da Doença , Regulação da Expressão Gênica , Imunidade Celular , Técnicas Imunoenzimáticas , Tuberculose Latente/genética , Tuberculose Latente/metabolismo , Pulmão/metabolismo , Vasos Linfáticos/imunologia , Masculino , Mediastino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos DBA , Reação em Cadeia da Polimerase em Tempo Real , Organismos Livres de Patógenos Específicos , Tuberculose Pulmonar/genética , Tuberculose Pulmonar/prevenção & controle , beta-Defensinas/biossíntese , beta-Defensinas/genéticaRESUMO
PURPOSE: To characterize the effect of glutamate receptor activation/inhibition on the secretion of vascular endothelial growth factor (VEGF) in retina-specific glial (Müller) cells under experimental conditions of hyperglycemia and hypoxia, two intrinsic pathologic conditions of diabetic retinopathy. METHODS: Purified rat Müller cells were grown in normoglycemic or diabetic-like, hyperglycemic (5.6 or 25 mM glucose, respectively) culture media under normoxic or chemically-induced hypoxic conditions. After treatments, cells were incubated with glutamate receptor agonists and antagonists and VEGF secretion was determined by ELISA. Cell viability was determined by Lactate Dehydrogenase (LDH) secretion-assay and Ki67 immunocytochemistry. Activation of the Akt signal transduction pathway was assessed by western blot using antibodies against phosphorylated Akt. The bio-activity of the secreted VEGF was analyzed by western blot with a phospho-VEGF receptor 2 specific antibody and an in vitro endothelial cell proliferation assay. RESULTS: In control (normoglycemic/normoxic) conditions, N-methyl-D-aspartate receptor (NMDA-R) antagonists MK801 and AP-5 increased secretion of VEGF from Müller cells, and this was not observed after AMPA/kainate receptor blockade. VEGF secretion after NMDA-R antagonists was independent of cell proliferation or cell lysis and it was maintained in cultures grown in hyperglycemia or hypoxia. However, under hyperglycemic and hypoxic conditions, the observed phenomenon was impaired. We also determined that NMDA-R blockade causes a rapid and sustained increase on Akt phosphorylation, a signaling molecule that has been previously linked to VEGF expression. Müller cell-derived VEGF was capable of promoting VEGF receptor 2 phosphorylation and proliferation of endothelial cells. CONCLUSIONS: Our results show that NMDA-R exert a tonic inhibition on VEGF secretion in cultures of rat purified Müller cells and indicate that in healthy retina, glutamatergic stimulation could potentially contribute to the protective antiangiogenic role of Müller glia. We suggest that conditions present on diabetic retinopathy could cause malfunction of control points on VEGF synthesis on Müller cells.
Assuntos
Antagonistas de Aminoácidos Excitatórios/farmacologia , Hiperglicemia/metabolismo , Hipóxia/metabolismo , Neuroglia/metabolismo , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Western Blotting , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Endotélio Vascular , Ensaio de Imunoadsorção Enzimática , Agonistas de Aminoácidos Excitatórios/farmacologia , Imuno-Histoquímica , Antígeno Ki-67/metabolismo , L-Lactato Desidrogenase/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Long-Evans , Receptores de N-Metil-D-Aspartato/metabolismo , Neurônios Retinianos/efeitos dos fármacos , Neurônios Retinianos/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
It has been reported that patients with progressive tuberculosis (TB) express abundant amounts of the antimicrobial peptides (AMPs) cathelicidin (LL-37) and human neutrophil peptide-1 (HNP-1) in circulating cells, whereas latent TB infected donors showed no differences when compared with purified protein derivative (PPD) and QuantiFERON®-TB Gold (QFT)-healthy individuals. The aim of this study was to determine whether LL-37 and HNP-1 production correlates with higher tuberculin skin test (TST) and QFT values in TB household contacts. Twenty-six TB household contact individuals between 26-58 years old TST and QFT positive with at last two years of latent TB infection were recruited. AMPs production by polymorphonuclear cells was determined by flow cytometry and correlation between TST and QFT values was analysed. Our results showed that there is a positive correlation between levels of HNP-1 and LL-37 production with reactivity to TST and/or QFT levels. This preliminary study suggests the potential use of the expression levels of these peptides as biomarkers for progression in latent infected individuals.