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1.
Bioorg Chem ; 146: 107249, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38493638

RESUMO

One of the deadliest infectious diseases, malaria, still has a significant impact on global morbidity and mortality. Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) catalyzes the fourth step in de novo pyrimidine nucleotide biosynthesis and has been clinically validated as an innovative and promising target for the development of novel targeted antimalarial drugs. PfDHODH inhibitors have the potential to significantly slow down parasite growth at the blood and liver stages. Several PfDHODH inhibitors based on various scaffolds have been explored over the past two decades. Among them, triazolopyrimidines, isoxazolopyrimidines, and pyrrole-based derivatives known as DSM compounds showed tremendous potential as novel antimalarial agents, and one of the triazolopyrimidine-based compounds (DSM265) was able to reach phase IIa clinical trials. DSM compounds were synthesized as PfDHODH inhibitors with various substitutions based on structure-guided medicinal chemistry approaches and further optimised as well. For the first time, this review provides an overview of all the synthetic approaches used for the synthesis, alternative synthetic routes, and novel strategies involving various catalysts and chemical reagents that have been used to synthesize DSM compounds. We have also summarized SAR study of all these PfDHODH inhibitors. In an attempt to assist readers, scientists, and researchers involved in the development of new PfDHODH inhibitors as antimalarials, this review provides accessibility of all synthetic techniques and SAR studies of the most promising triazolopyrimidines, isoxazolopyrimidines, and pyrrole-based PfDHODH inhibitors.


Assuntos
Antimaláricos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Antimaláricos/química , Plasmodium falciparum , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/química , Pirróis/farmacologia , Di-Hidro-Orotato Desidrogenase , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química
2.
Homeopathy ; 105(2): 202-8, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27211328

RESUMO

BACKGROUND: Seasonal allergic rhinitis (hay fever) is common and can considerably reduce the quality of life of sufferers. Despite the wide everyday application and promising results with homeopathy, scientific evidence of its effectiveness for most ailments is scarce. AIM: The assessment of the clinical effectiveness of homeopathic remedies in the alleviation of hay fever symptoms in a typical clinical setting. METHODS: We performed a clinical observational study of eight patients in the treatment of hay fever symptoms over a two-year period (2012 and 2013) using Measure Yourself Medical Outcome Profile (MYMOP) self-evaluation questionnaires at baseline and again after two weeks and four weeks of homeopathic treatment. The individualized prescription - either a single remedy or multiple remedies - was based on the totality of each patient's symptoms. RESULTS: The average MYMOP scores for the eyes, nose, activity and wellbeing had improved significantly after two and four weeks of homeopathic treatment. The overall average MYMOP profile score at baseline was 3.83 (standard deviation, SD, 0.78). After 14 and 28 days of treatment the average score had fallen to 1.14 (SD, 0.36; P<0.001) and 1.06 (SD, 0.25; P<0.001) respectively. CONCLUSIONS: Individualized homeopathic treatment was associated with significant alleviation of hay fever symptoms, enabling the reduction in use of conventional treatment. The results presented in this study can be considered as a step towards a pilot pragmatic study that would use more robust outcome measures and include a larger number of patients prescribed a single or a multiple homeopathic prescription on an individualized basis.


Assuntos
Homeopatia , Rinite Alérgica Sazonal/tratamento farmacológico , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Rinite Alérgica Sazonal/patologia , Índice de Gravidade de Doença , Inquéritos e Questionários , Resultado do Tratamento , Adulto Jovem
3.
Front Immunol ; 15: 1404122, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38979411

RESUMO

Introduction: Chronic obstructive pulmonary disease (COPD) is a major global cause of mortality with limited effective treatments. Sirtuins (SIRT) are histone deacetylases that are involved in the regulation of redox and inflammatory homeostasis. Hence, the present study aims to investigate the role of SIRT-2 in modulating inflammation in a murine model of COPD. Methods: COPD in mice was established by cigarette smoke (CS) exposure for 60 days, and AK-7 was used as the specific SIRT-2 inhibitor. AK-7 (100 µg/kg and 200 µg/kg body weight) was administered intranasally 1 h before CS exposure. Molecular docking was performed to analyze the binding affinity of different inflammatory proteins with AK-7. Results: Immune cell analysis showed a significantly increased number of macrophages (F4/80), neutrophils (Gr-1), and lymphocytes (CD4+, CD8+, and CD19+) in the COPD, group and their population was declined by AK-7 administration. Total reactive oxygen species, total inducible nitric oxide synthase, inflammatory mediators such as neutrophil elastase, C-reactive protein, histamine, and cytokines as IL4, IL-6, IL-17, and TNF-α were elevated in COPD and declined in the AK-7 group. However, IL-10 showed reverse results representing anti-inflammatory potency. AK-7 administration by inhibiting SIRT-2 decreased the expression of p-NF-κB, p-P38, p-Erk, and p-JNK and increased the expression of Nrf-2. Furthermore, AK-7 also declined the lung injury by inhibiting inflammation, parenchymal destruction, emphysema, collagen, club cells, and Kohn pores. AK-7 also showed good binding affinity with inflammatory proteins. Discussion: The current study reveals that SIRT-2 inhibition mitigates COPD severity and enhances pulmonary therapeutic interventions, suggesting AK-7 as a potential therapeutic molecule for COPD medication development.


Assuntos
NF-kappa B , Estresse Oxidativo , Doença Pulmonar Obstrutiva Crônica , Sirtuína 2 , Animais , Sirtuína 2/metabolismo , Sirtuína 2/antagonistas & inibidores , Camundongos , Doença Pulmonar Obstrutiva Crônica/metabolismo , Doença Pulmonar Obstrutiva Crônica/imunologia , Doença Pulmonar Obstrutiva Crônica/etiologia , Estresse Oxidativo/efeitos dos fármacos , NF-kappa B/metabolismo , Masculino , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Pulmão/patologia , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/efeitos dos fármacos , Modelos Animais de Doenças , Transdução de Sinais , Camundongos Endogâmicos C57BL , Citocinas/metabolismo , Carbazóis
4.
Free Radic Biol Med ; 212: 94-116, 2024 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-38142953

RESUMO

Opioids regulate various physiological and pathophysiological functions, including cell proliferation, immune function, obesity, and neurodegenerative disorders. They have been used for centuries as a treatment for severe pain, binding to opioid receptors a specific G protein-coupled receptor. Common opioids, like ß-endorphin, [D-Ala2, N-MePhe4, Gly-ol]-enkephalin (DAMGO), and dynorphins, have analgesic effects. The use of a potent antagonist, like naltrexone hydrochloride, to block the effects of mu Opioid Receptor (µOR) may result in the withdrawal of physiological effects and could potentially impact immune responses in many diseases including respiratory disease. Asthma is a respiratory disease characterized by airway hyperresponsiveness, inflammation, bronchoconstriction, chest tightness, stress generation and release of various cytokines. Airway inflammation leads recruitment and activation of immune cells releasing mediators, including opioids, which may modulate inflammatory response by binding to their respective receptors. The study aims to explore the role of µOR antagonist (naltrexone) in regulating asthma pathophysiology, as the regulation of immune and inflammatory responses in asthma remains unclear. Balb/c mice were sensitized intranasally by 1% TDI and challenged with 2.5% TDI. Naltrexone hydrochloride (1 mg/kg body weight) was administered through intraperitoneal route 1 h before TDI induction. Blocking µOR by naltrexone exacerbates airway inflammation by recruiting inflammatory cells (lymphocytes and neutrophils), enhancing intracellular Reactive oxygen species in bronchoalveolar lavage fluid (BALF), and inflammatory mediator (histamine, Eosinophil peroxidase and neutrophil elastase) in lungs. Naltrexone administration modulated inflammatory cytokines (TNF-α, IL-4, IL-5, IL-6, IL-10, and IL-17A), and enhanced IgE and CRP levels. Naltrexone administration also increased the expression of NF-κB, and phosphorylated p-P38, p-Erk, p-JNK and NF-κB by inhibiting the µOR. Docking study revealed good binding affinity of naltrexone with µOR compared to δ and κ receptors. In future it might elucidate potential therapeutic against many respiratory pathological disorders. In conclusion, µOR blocking by naltrexone regulates and implicates inflammation, bronchoconstriction, and lung physiology.


Assuntos
Asma , Naltrexona , Animais , Camundongos , Naltrexona/farmacologia , Naltrexona/uso terapêutico , NF-kappa B/metabolismo , Receptores Opioides mu/metabolismo , Receptores Opioides mu/uso terapêutico , Modelos Animais de Doenças , Asma/tratamento farmacológico , Inflamação/patologia , Pulmão/metabolismo , Citocinas/metabolismo , Estresse Oxidativo , Camundongos Endogâmicos BALB C , Ovalbumina
5.
Sci Rep ; 13(1): 12414, 2023 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-37524754

RESUMO

Asthma, a chronic respiratory disease is characterized by airway inflammation, remodelling, airflow limitation and hyperresponsiveness. At present, it is considered as an umbrella diagnosis consisting several variable clinical presentations (phenotypes) and distinct pathophysiological mechanisms (endotypes). Recent evidence suggests that oxidative stress participates in airway inflammation and remodelling in chronic asthma. Opioids resembled by group of regulatory peptides have proven to act as an immunomodulator. ß-Endorphin a natural and potent endogenous morphine produced in the anterior pituitary gland play role in pain modulation. Therapeutic strategy of many opioids including ß-Endorphin as an anti­inflammatory and antioxidative agent has not been yet explored despite its promising analgesic effects. This is the first study to reveal the role of ß-Endorphin in regulating airway inflammation, cellular apoptosis, and oxidative stress via Nrf-2 in an experimental asthmatic model. Asthma was generated in balb/c mice by sensitizing with 1% Toulene Diisocyanate on day 0, 7, 14 and 21 and challenging with 2.5% Toulene Diisocyanate from day 22 to 51 (on every alternate day) through intranasal route. ß-Endorphin (5 µg/kg) was administered through the nasal route 1 h prior to sensitization and challenge. The effect of ß-Endorphin on pulmonary inflammation and redox status along with parameters of oxidative stress were evaluated. We found that pre-treatment of ß-Endorphin significantly reduced inflammatory infiltration in lung tissue and cell counts in bronchoalveolar lavage fluid. Also, pre-treatment of ß-Endorphin reduced reactive oxygen species, Myeloperoxidase, Nitric Oxide, Protein and protein carbonylation, Glutathione Reductase, Malondialdehyde, IFN-γ, and TNF-α. Reversely, ß-Endorphin significantly increased Superoxide dismutase, Catalase, glutathione, Glutathione-S-Transferase, and activation of NF-E2-related factor 2 (Nrf-2) via Kelch-like ECH-associated protein 1 (Keap1), independent pathway in the lung restoring architectural alveolar and bronchial changes. The present findings reveal the therapeutic potency of ß-END in regulating asthma by Keap-1 independent regulation of Nrf-2 activity. The present findings reveal the therapeutic potency of ß-Endorphin in regulating asthma.


Assuntos
Analgésicos Opioides , Asma , Camundongos , Animais , Analgésicos Opioides/farmacologia , beta-Endorfina/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Modelos Animais de Doenças , Fator 2 Relacionado a NF-E2/metabolismo , Asma/metabolismo , Estresse Oxidativo , Inflamação/tratamento farmacológico , Líquido da Lavagem Broncoalveolar , Glutationa/metabolismo , Apoptose , Camundongos Endogâmicos BALB C
6.
Free Radic Res ; : 1-20, 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-38078439

RESUMO

Chronic obstructive pulmonary disease (COPD) is defined by inflammation and emphysema. Sirtuins (SIRT) are NAD+-dependent histone deacetylases that regulate oxidative stress and inflammation. The present work investigates the modulatory role of SIRT-2 in experimental COPD model. Insilico comparative assessment of SIRT-2 inhibitors (AK-7 and AGK-2) by ADMET and molecular docking revealed AK-7 as suitable candidate for invivo application. COPD in mice was established by cigarette smoke (CS) exposure for 2 months. AK-7 (100 µg/kg and 200 µg/kg body weight) was administered intranasally one hour before CS exposure. The present investigation demonstrates that CS exposure increases total cell count, and free radical production (total reactive oxygen species, total oxidant status, myeloperoxidase, and nitric oxide), which were decreased by AK-7. It also altered antioxidant enzymatic activity (total antioxidant status, catalase, superoxide dismutase, glutathione peroxidase, glutathione-s-transferase, glutathione reductase, and reduced glutathione), hence preserving the redox balance. AK-7 significantly decreases apoptosis, protein carbonylation, lipid peroxidation, TNF-α and IFN-ï»» levels represent COPD generation in mice and were dramatically decreased by AK-7. Histopathological studies shows that CS exposure damages alveoli and produces peribronchiolar inflammation; both of these events were reduced by AK-7. The antioxidative potency of AK-7 was confirmed by observing Nrf2 and Keap1 proteins. Keap-dependent Nrf2 regulation was observed, with cytosolic Nrf2 and Keap1 expression elevated in COPD and reduced in the AK-7 group while nuclear Nrf2 was reduced in COPD and increased in the AK-7 group. The present study concludes that inhibition of SIRT-2 minimizes COPD severity and mediates therapeutic effects in the lungs.

7.
Sci Rep ; 13(1): 1131, 2023 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-36670131

RESUMO

Oxidative stress and inflammation are hypothesised as the main contributor for Chronic Obstructive Pulmonary Disease (COPD). Cigarette smoke (CS), a major cause of COPD leads to inflammation resulting in recruitment of neutrophils and macrophages which are rich sources of oxidants. Activation of these cells produces excess oxidants and depletes antioxidants resulting in stress. Presently, effective drug for COPD is limited; therefore, novel compounds from natural sources, including plants are under exploration. The present study aims to investigate the protective effect of Ocimum sanctum leaf extract (OLE) in CS - induced model of COPD. Exposure to CS was performed thrice a week for 8 weeks and OLE (200 mg/kg and 400 mg/kg) was administered an hour before CS exposure. Control group (negative control) were exposed to ambient air while COPD group was exposed to CS (positive control). Administration of OLE doses reduced inflammation, decreased oxidant concentration and increased antioxidant concentration (p < 0.01). Molecular docking studies between the major phytocompounds of OLE (Eugenol, Cyclohexane and Caryophyllene) and antioxidant enzymes Superoxide dismutase (SOD), Catalase, Glutathione peroxidase (GPx), Glutathione reductase (GR) and Glutathione S Transferase (GST) showed strong binding interaction in terms of binding energy. In vivo and in silico findings for the first time indicates that OLE extract significantly alleviates oxidative stress by its potent free radical scavenging property and strong interaction with antioxidant enzymes. OLE extract may prove to be a therapeutic option for COPD prevention and treatment.


Assuntos
Lesão Pulmonar , Doença Pulmonar Obstrutiva Crônica , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Ocimum sanctum , Lesão Pulmonar/metabolismo , Simulação de Acoplamento Molecular , Extratos Vegetais/uso terapêutico , Oxirredução , Estresse Oxidativo , Oxidantes/metabolismo , Inflamação/metabolismo , Pulmão/metabolismo
8.
Ann Thorac Surg ; 111(1): e37-e39, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32599048

RESUMO

Primary squamous cell carcinoma of the sternum is very rare. Imaging features are not specific, and a biopsy specimen may help identify the pathology. Positron emission tomography scan helps rule out a primary focus elsewhere. The treatment will be surgical management, if operable. We encountered a patient with primary squamous cell carcinoma of the sternum with an unusual presentation. After the diagnostic workup, we managed the patient surgically with resection, followed by titanium mesh reconstruction and pectoralis major flap cover. We present the case in view of its rarity and to emphasize the key surgical points.


Assuntos
Neoplasias Ósseas , Carcinoma de Células Escamosas , Esterno , Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/cirurgia , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade
9.
Biochem J ; 422(3): 503-12, 2009 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-19548879

RESUMO

NAADP (nicotinic acid-adenine dinucleotide phosphate) is an unusual second messenger thought to mobilize acidic Ca(2+) stores, such as lysosomes or lysosome-like organelles, that are functionally coupled to the ER (endoplasmic reticulum). Although NAADP-sensitive Ca(2+) stores have been described in neurons, the physiological cues that recruit them are not known. Here we show that in both hippocampal neurons and glia, extracellular application of glutamate, in the absence of external Ca(2+), evoked cytosolic Ca(2+) signals that were inhibited by preventing organelle acidification or following osmotic bursting of lysosomes. The sensitivity of both cell types to glutamate correlated well with lysosomal Ca(2+) content. However, interfering with acidic compartments was largely without effect on the Ca(2+) content of the ER or Ca(2+) signals in response to ATP. Glutamate but not ATP elevated cellular NAADP levels. Our results provide evidence for the agonist-specific recruitment of NAADP-sensitive Ca(2+) stores by glutamate. This links the actions of NAADP to a major neurotransmitter in the brain.


Assuntos
Sinalização do Cálcio/efeitos dos fármacos , Cálcio/metabolismo , Ácido Glutâmico/farmacologia , NADP/análogos & derivados , Animais , Células Cultivadas , Feminino , Hipocampo/citologia , Técnicas In Vitro , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , NADP/metabolismo , Neuroglia/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley , Ratos Wistar
10.
Indian J Pathol Microbiol ; 63(1): 106-108, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32031135

RESUMO

Monotypic angiomyolipoma is usually found in the kidneys and is composed predominantly of epithelioid cells which show positivity for melanocyte and smooth muscle markers. It can pose a diagnostic challenge due to a range of differential diagnosis. We report the second case of monotypic angiomyolipoma of nasal cavity and first from India in a 54-year-old male who presented with a nasal polyp. Grossly the tumor was well circumscribed and un-encapsulated. Microscopy showed a large number of epithelioid cells mixed with a few spindle cells, varying sized blood vessels, and focal areas of adipose tissue. Immunohistochemistry was positive for smooth muscle actin (SMA) and human melanoma black (HMB-45) stains. It is important to identify this tumor as it can sometimes be mistaken for malignancy and only needs endoscopic resection.


Assuntos
Angiomiolipoma/diagnóstico por imagem , Epistaxe/etiologia , Cavidade Nasal/patologia , Neoplasias Nasais/diagnóstico por imagem , Biomarcadores Tumorais , Diagnóstico Diferencial , Técnicas Histológicas , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Cavidade Nasal/diagnóstico por imagem , Pólipos Nasais/patologia , Neoplasias Nasais/cirurgia , Tomografia Computadorizada por Raios X
11.
J Midlife Health ; 9(1): 47-49, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29628731

RESUMO

A breast mass in a postmenopausal age woman is treated with a high index of clinical suspicion for malignancy. Myofibroblastoma (MFB) of the breast is a very rare benign stromal tumor, predominantly occurring in menopausal women and older men. Owing to its rarity, nonspecific radiology, cytomorphology, and many variants, it can be confused with other malignant and benign breast lesions and hence can be a source of diagnostic pitfall. We present a case of an MFB of the breast in a 55-year-old female, which was detected on a routine screening mammography. Fine-needle aspiration cytology was inconclusive. Final diagnosis was made by histopathology and immunohistochemistry examination. We report this case as the likelihood of encountering MFB has increased in recent years due to routine mammographic screening, and this lesion should be kept in the differential diagnosis of spindle-cell lesions of the breast.

12.
Indian J Pathol Microbiol ; 61(3): 437-439, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30004076

RESUMO

Spermatocytic seminoma (SCS) is an indolent germ cell tumor of the testis. It has an excellent prognosis and orchidectomy is generally curative. Very rarely, it can be complicated by a sarcomatous transformation which is associated with a very aggressive behavior and requires adjuvant therapy. SCS with sarcomatous component is a very rare occurrence with <20 cases described in the world literature of which eight showed rhabdomyoblastic differentiation. We report a case of SCS with rhabdomyosarcomatous differentiation in a 60-year-old male along with a short review of literature.


Assuntos
Diferenciação Celular , Rabdomiossarcoma/diagnóstico , Seminoma/diagnóstico , Neoplasias Testiculares/diagnóstico , Testículo/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Orquiectomia , Prognóstico , Rabdomiossarcoma/patologia , Rabdomiossarcoma/ultraestrutura , Seminoma/patologia , Neoplasias Testiculares/patologia , Testículo/citologia , Testículo/diagnóstico por imagem , Ultrassonografia
13.
J Clin Diagn Res ; 11(6): ED26-ED28, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28764185

RESUMO

Kikuchi-Fujimoto Disease (KFD) is a self-limiting necrotizing lymphadenitis that usually presents with fever and cervical lymphadenopathy. Recognition of this condition is crucial, because it can be mistaken for tuberculosis, lymphoma and connective tissue disorders. When present at an unusual location the diagnosis can be challenging. We present an unusual case of Kikuchi-Fujimoto disease involving mesenteric lymph node masquerading as acute appendicitis along with its differential diagnosis. A 30-year-old female presented with complaints of acute abdominal pain, vomiting and fever. Physical examination revealed rebound tenderness in the right iliac fossa. The abdominal sonography was suspicious of acute appendicitis. The patient underwent appendectomy with excision of an enlarged mesenteric lymph node. On histopathology mesenteric node showed features of KFD which was confirmed on immunohistochemistry. Appendix was unremarkable. Although rare KFD should be added to the differential diagnosis of acute appendicitis in patients with enlarged mesenteric lymph nodes, Awareness of this disorder helps to prevent misdiagnosis and inappropriate treatment.

15.
J Biol Chem ; 281(23): 15923-8, 2006 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-16595650

RESUMO

Cells possess several Ca2+-mobilizing messengers, which couple stimulation at the cell surface by a multitude of extracellular cues to the regulation of intracellular Ca2+-sensitive targets. Recent studies suggest that agonists differentially select from this molecular palette to generate their characteristic Ca2+ signals but it is still unclear whether different messengers mediate different functions or whether they act in a redundant fashion. In this study, we compared the effects of nicotinic acid adenine dinucleotide phosphate (NAADP), a novel Ca2+-mobilizing messenger, with that of the prototypical messenger inositol trisphosphate on cytosolic Ca2+ levels and differentiation status of PC12 cells. We demonstrate that liposomal delivery of NAADP mediated release of Ca2+ from acidic Ca2+ stores and that this stimulus was sufficient to drive differentiation of the cells to a neuronal-like phenotype. In sharp contrast, cell fate was unaffected by more transient Ca2+ signals generated by inositol trisphosphate-evoked release of endoplasmic reticulum Ca2+ stores. Our data establish for the first time (i) the presence of novel NAADP-sensitive Ca2+ stores in PC12 cells, (ii) a role for NAADP in differentiation, and (iii) that Ca2+-dependent function can be messenger-specific. Thus, differential recruitment of intracellular Ca2+-mobilizing messengers and their target Ca2+ stores may represent a robust means of maintaining stimulus fidelity in the control of Ca2+-dependent cell function.


Assuntos
Cálcio/metabolismo , Diferenciação Celular/efeitos dos fármacos , NADP/análogos & derivados , Neurônios/efeitos dos fármacos , Animais , Citosol/efeitos dos fármacos , Citosol/metabolismo , NADP/farmacologia , Neurônios/citologia , Neurônios/metabolismo , Células PC12 , Ratos
16.
J Immunol ; 172(7): 4048-58, 2004 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-15034016

RESUMO

Mast cells are key regulators in allergy and inflammation, and release histamine, cytokines, and other proinflammatory mediators. In the classical view, IgE acts merely to prime mast cells, attaching to FcepsilonRs but not evoking any cell signaling response until cross-linked by the presence of a multivalent allergen. However, several recent studies have reported that IgE alone can promote cell survival and cytokine production in the absence of cross-linking by allergen. In this study we demonstrate that acute addition of monomeric IgE elicits a wide spectrum of responses in the rat basophilic leukemia-2H3 mast cell line, including activation of phospholipases Cgamma and D, a rise in cytosol Ca(2+), NFAT translocation, degranulation, and membrane ruffling within minutes. Calcium transients persist for hours as long as IgE is present resulting in the maintained translocation of the transcription factor NFAT to the nucleus. Removal of IgE reverses the signaling processes. Our results indicate that, far from simply preparing the cells for a response to allergen, monomeric IgE can stimulate signaling pathways that lead to degranulation, membrane ruffling, and NFAT translocation. The mechanism of activation is likely to be via aggregation of the FcepsilonR1 because activation by IgE can be inhibited with monovalent hapten.


Assuntos
Cálcio/metabolismo , Degranulação Celular/imunologia , Núcleo Celular/metabolismo , Citosol/metabolismo , Proteínas de Ligação a DNA/metabolismo , Imunoglobulina E/fisiologia , Leucemia de Mastócitos/imunologia , Proteínas Nucleares , Fatores de Transcrição/metabolismo , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Transporte Ativo do Núcleo Celular/imunologia , Androstadienos/farmacologia , Animais , Sinalização do Cálcio/efeitos dos fármacos , Sinalização do Cálcio/imunologia , Degranulação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Membrana Celular/imunologia , Membrana Celular/metabolismo , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/imunologia , Ativação Enzimática/efeitos dos fármacos , Imunoglobulina E/isolamento & purificação , Imunossupressores/farmacologia , Leucemia de Mastócitos/enzimologia , Leucemia de Mastócitos/metabolismo , Leucemia de Mastócitos/patologia , Mastócitos/enzimologia , Mastócitos/imunologia , Mastócitos/metabolismo , Fatores de Transcrição NFATC , Fosfolipase D/metabolismo , Ratos , Wortmanina
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