RESUMEN
Neurofibromatosis type 1 (NF1) is a genetic disorder with an early mortality determined mostly by malignancy. Little is known about the immunosurveillance factors in NF1 patients. In this study we evaluated inflammatory markers and their cellular sources in NF1 patients to try understanding the relation of immune factors and the tumorigenesis that characterizes the disease. Using flow cytometry and ELISA, we assayed cytokines, co-stimulatory molecules, the functional state of circulating blood cells and cytokine plasma levels in a case-control transversal study. The frequency of CD4+ T cells seems reduced. In addition, a shift towards an anti-inflammatory profile was observed in cells expressing cytokines, except for a small subpopulation of CD8+ T cells that displayed an increased frequency of cells expressing the pro-inflammatory cytokine Tumor necrosis factor (TNF-α), while plasma soluble levels of Transforming growth factor-beta (TGF-ß) and interleukin-6 (IL-6) were increased in NF1 patients. Knowledge of the regulation of NF1 and the role of TGF-beta signaling pathway in malignant peripheral nerve sheath tumor pathogenesis might shed light on molecular carcinogenesis mechanisms and lead to putative interventions both in prevention and treatment of malignant tumors.
Asunto(s)
Citocinas/metabolismo , Leucocitos/metabolismo , Neurofibromatosis 1/inmunología , Adolescente , Adulto , Biomarcadores/metabolismo , Niño , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Humanos , Leucocitos/patología , Masculino , Persona de Mediana Edad , Neurofibromatosis 1/metabolismo , Neurofibromatosis 1/patología , Linfocitos T/inmunología , Adulto JovenRESUMEN
Studies suggest that inflammation is involved in the neurodegenerative cascade of dementias. Immunological mechanisms may be part of the pathophysiological process in frontotemporal dementia (FTD), but up till now only vague evidence of such mechanisms has been presented. The B7- CD28/CTLA-4 pathway is an important immunological signaling pathway involved in modulation of T cell activation. The aim of this study was to compare the expression of molecules associated with co-stimulatory signaling in peripheral blood mononuclear cells (PBMC) of FTD to Alzheimer disease (AD) and control groups. Our results confirm the previous demonstrated increased expression of CD80 in CD14+ Alzheimer patients T cells but show, for the first time, a reduction in the expression of CTLA-4 in CD4+ FTD cells. As CTLA-4 is the most potent negative regulators of T-cell activation we speculated that peripheral T lymphocytes in FTD are more activated and this could be involved in the neurodegeneration observed in this dementia.
Asunto(s)
Enfermedad de Alzheimer/patología , Antígeno CTLA-4/metabolismo , Demencia Frontotemporal/patología , Linfocitos T/metabolismo , Antígenos CD/metabolismo , Linfocitos B/metabolismo , Brasil , Femenino , Antígenos HLA-DR/metabolismo , Humanos , MasculinoRESUMEN
It is well known that dopamine imbalances are associated with many psychiatric disorders and that the dopaminergic receptor D2 is the main target of antipsychotics. Recently it was shown that levels of two proteins implicated in dopaminergic signaling, Neuronal calcium sensor-1 (NCS-1) and DARPP-32, are altered in the prefrontal cortex (PFC) of both schizophrenic and bipolar disorder patients. NCS-1, which inhibits D2 internalization, is upregulated in the PFC of both patients. DARPP-32, which is a downstream effector of dopamine signaling, integrates the pathways of several neurotransmitters and is downregulated in the PFC of both patients. Here, we used PC12 cells stably overexpressing NCS-1 (PC12-NCS-1 cells) to address the function of this protein in DARPP-32 signaling pathway in vitro. PC12-NCS-1 cells displayed downregulation of the cAMP/PKA pathway, with decreased levels of cAMP and phosphorylation of CREB at Ser133. We also observed decreased levels of total and phosphorylated DARPP-32 at Thr34. However, these cells did not show alterations in the levels of D2 and phosphorylation of DARPP-32 at Thr75. These results indicate that NCS-1 modulates PKA/cAMP signaling pathway. Identification of the cellular mechanisms linking NCS-1 and DARPP-32 may help in the understanding the signaling machinery with potential to be turned into targets for the treatment of schizophrenia and other debilitating psychiatric disorders.
Asunto(s)
Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Proteínas Sensoras del Calcio Neuronal/genética , Neuropéptidos/genética , Animales , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Fosfoproteína 32 Regulada por Dopamina y AMPc/metabolismo , Regulación hacia Abajo/genética , Regulación hacia Abajo/fisiología , Proteínas Sensoras del Calcio Neuronal/metabolismo , Proteínas Sensoras del Calcio Neuronal/fisiología , Neuropéptidos/metabolismo , Neuropéptidos/fisiología , Células PC12 , Fosforilación , Ratas , Receptores de Dopamina D2/metabolismo , Receptores de Dopamina D2/fisiología , Transducción de Señal/genética , Transducción de Señal/fisiología , Transfección , Regulación hacia Arriba/genéticaRESUMEN
BACKGROUND: Schizophrenia is the major psychiatry disorder, which the exact cause remains unknown. However, it is well known that dopamine-mediated neurotransmission imbalance is associated with this pathology and the main target of antipsychotics is the dopamine receptor D2. Recently, it was described alteration in levels of two dopamine signaling related proteins in schizophrenic prefrontal cortex (PFC): Neuronal Calcium Sensor-1 (NCS-1) and DARPP-32. NCS-1, which is upregulated in PFC of schizophrenics, inhibits D2 internalization. DARPP-32, which is decreased in PFC of schizophrenics, is a key downstream effector in transducing dopamine signaling. We previously demonstrated that antipsychotics do not change levels of both proteins in rat's brain. However, since NCS-1 and DARPP-32 levels are not altered in wild type rats, we treated wild type PC12 cells (PC12 WT) and PC12 cells stably overexpressing NCS-1 (PC12 Clone) with antipsychotics to investigate if NCS-1 upregulation modulates DARPP-32 expression in response to antipsychotics treatment. RESULTS: We chronically treated both PC12 WT and PC12 Clone cells with typical (Haloperidol) or atypical (Clozapine and Risperidone) antipsychotics for 14 days. Using western blot technique we observed that there is no change in NCS-1 and DARPP-32 protein levels in both PC12 WT and PC12 Clone cells after typical and atypical antipsychotic treatments. CONCLUSIONS: Because we observed no alteration in NCS-1 and DARPP-32 levels in both PC12 WT and Clone cells treated with typical or atypical antipsychotics, we suggest that the alteration in levels of both proteins in schizophrenic's PFC is related to psychopathology but not with antipsychotic treatment.
Asunto(s)
Antipsicóticos/farmacología , Fosfoproteína 32 Regulada por Dopamina y AMPc/metabolismo , Proteínas Sensoras del Calcio Neuronal/metabolismo , Neuropéptidos/metabolismo , Animales , Western Blotting , Células Clonales , Células PC12 , RatasRESUMEN
Until now, there are no conclusive data about the mechanisms involved in motor symptoms of Sydenham's chorea (SC). Taking into account the autoreactive antibody-mediated hypothesis of SC pathogenesis, the SC may be associated with uncontrolled immune mechanisms. Besides the antibody hypothesis, the innate immune system has been underappreciated. Hence, we evaluated the activation state of monocytes, cells that are precursors of macrophages, to characterize the inflammation profile of patients. We assessed the surface molecules CD80, CD86, and human leukocyte antigen DR expression in patients with SC by flow cytometry analysis. Our results showed a decreased CD14(+) (monocyte) frequency, with concomitant increased CD14(-) frequency inside monocyte population. Although monocyte population showed a decreased human leukocyte antigen DR and CD86 frequencies, the CD14(-) population showed an increased frequency of CD80(+) monocyte from SC compared with controls. These data suggest that monocytes showed a reduced costimulatory potential in SC.
Asunto(s)
Antígenos CD/metabolismo , Antígenos de Diferenciación/metabolismo , Corea/inmunología , Corea/patología , Monocitos/metabolismo , Adolescente , Adulto , Presentación de Antígeno , Antígenos CD/genética , Antígenos CD/inmunología , Antígenos de Diferenciación/genética , Antígenos de Diferenciación/inmunología , Separación Celular , Células Cultivadas , Corea/sangre , Femenino , Citometría de Flujo , Antígenos HLA-DR/inmunología , Antígenos HLA-DR/metabolismo , Humanos , Inmunidad Innata , Masculino , Monocitos/inmunología , Monocitos/patologíaRESUMEN
Dopamine-mediated neurotransmission imbalances are associated with several psychiatry illnesses, such as schizophrenia. Recently it was demonstrated that two proteins involved in dopamine signaling are altered in prefrontal cortex (PFC) of schizophrenic patients. DARPP-32 is a key downstream effector of intracellular signaling pathway and is downregulated in PFC of schizophrenic subjects. NCS-1 is a neuronal calcium sensor that can inhibit dopamine receptor D2 internalization and is upregulated in PFC of schizophrenic subjects. It is well known that dopamine D2 receptor is the main target of antipsychotic. Therefore, our purpose was to study if chronic treatment with typical or atypical antipsychotics induced alterations in DARPP-32 and NCS-1 expression in five brain regions: prefrontal cortex, hippocampus, striatum, cortex and cerebellum. We did not find any changes in DARPP-32 and NCS-1 protein expression in any brain region investigated.
Asunto(s)
Antipsicóticos/farmacología , Química Encefálica/efectos de los fármacos , Fosfoproteína 32 Regulada por Dopamina y AMPc/biosíntesis , Proteínas Sensoras del Calcio Neuronal/biosíntesis , Neuropéptidos/biosíntesis , Animales , Western Blotting , Densitometría , Masculino , Ratas , Ratas Wistar , Receptores de Dopamina D2/biosíntesis , Regulación hacia Arriba/efectos de los fármacosRESUMEN
Signaling pathways play important roles in the coordination and integration of a myriad cellular functions. Because of widespread interest in the dopaminergic pathways, the protein dopamine and cyclic adenosine 3',5'-monophosphate-regulated phosphoprotein with molecular weight of 32 kDa, known by the acronym DARPP-32, occupies a central role in the biology of dopaminoceptive neurons in the central and peripheral nervous system (PNS). Its involvement has been demonstrated in many neural phenomena, including physiologic and pathologic neuroplasticity to drug effects and cognition. However, DARPP-32 has also been identified in non-neuronal tissues and its level of expression has been associated with the malignant level of some types of cancer, via modulation of cell survival and differentiation. This review considers some of these apparently compartmentalized functions of DARPP-32 and its potential as a therapeutic target.
Asunto(s)
Antineoplásicos/farmacología , Fármacos del Sistema Nervioso Central/farmacología , Fosfoproteína 32 Regulada por Dopamina y AMPc/antagonistas & inhibidores , Fosfoproteína 32 Regulada por Dopamina y AMPc/metabolismo , HumanosRESUMEN
Although most T lymphocytes express the alphabeta T-cell receptor and either CD4 or CD8 molecules, a small population of cells lacking these coreceptors, CD4- CD8- (double negative [DN]) T cells, has been identified in the peripheral immune system of mice and humans. To better understand the role that this population may have in the human immune response against Leishmania spp., a detailed study defining the activation state, cytokine profile, and the heterogeneity of DN T cells bearing alphabeta or gammadelta T-cell receptors was performed with a group of well-defined cutaneous leishmaniasis patients. Strikingly, on average 75% of DN T cells from cutaneous leishmaniasis patients expressed the alphabeta T-cell receptor, with the remainder expressing the gammadelta receptor, while healthy donors displayed the opposite distribution with approximately 75% of the DN T cells expressing the gammadelta T-cell receptor. Additionally, alphabeta DN T cells from cutaneous leishmaniasis patients are compatible with previous antigen exposure and recent activation. Moreover, while alphabeta DN T cells from Leishmania-infected individuals present a proinflammatory cytokine profile, gammadelta DN T cells express a regulatory profile exemplified by interleukin-10 production. The balance between these subpopulations could allow for the formation of an effective cellular response while limiting its pathogenic potential.
Asunto(s)
Antígenos CD4 , Antígenos CD8 , Leishmaniasis Cutánea/inmunología , Receptores de Antígenos de Linfocitos T alfa-beta/metabolismo , Receptores de Antígenos de Linfocitos T gamma-delta/metabolismo , Subgrupos de Linfocitos T/inmunología , Linfocitos T/clasificación , Linfocitos T/inmunología , Adolescente , Adulto , Anciano , Antígenos CD4/metabolismo , Antígenos CD8/metabolismo , Células Cultivadas , Niño , Preescolar , Citocinas/biosíntesis , Femenino , Humanos , Leishmaniasis Cutánea/metabolismo , Leishmaniasis Cutánea/patología , Activación de Linfocitos/inmunología , Masculino , Persona de Mediana Edad , Subgrupos de Linfocitos T/metabolismo , Linfocitos T/metabolismoRESUMEN
The participation of type I IFNs (IFN-I) in NO production and resistance to Trypanosoma cruzi infection was investigated. Adherent cells obtained from the peritoneal cavity of mice infected by the i.p. route produced NO and IFN-I. Synthesis of NO by these cells was partially inhibited by treatment with anti-IFN-alphabeta or anti-TNF-alpha Abs. Compared with susceptible BALB/c mice, peritoneal cells from parasite-infected resistant C57BL/6 mice produced more NO (2-fold), IFN-I (10-fold), and TNF-alpha (3.5-fold). Later in the infection, IFN-I levels measured in spleen cell (SC) cultures from 8-day infected mice were greater in C57BL/6 than in infected BALB/c mice, and treatment of the cultures with anti-IFN-alphabeta Ab reduced NO production. IFN-gamma or IL-10 production by SCs was not different between the two mouse strains; IL-4 was not detectable. Treatment of C57BL/6 mice with IFN-I reduced parasitemia levels in the acute phase of infection. Mice deprived of the IFN-alphabetaR gene developed 3-fold higher parasitemia levels in the acute phase in comparison with control 129Sv mice. Production of NO by peritoneal macrophages and SCs was reduced in mice that lacked signaling by IFN-alphabeta, whereas parasitism of macrophages was heavier than in control wild-type mice. We conclude that IFN-I costimulate NO synthesis early in T. cruzi infection, which contributes to a better control of the parasitemia in resistant mice.
Asunto(s)
Enfermedad de Chagas/metabolismo , Enfermedad de Chagas/prevención & control , Interferón-alfa/biosíntesis , Interferón beta/biosíntesis , Óxido Nítrico/biosíntesis , Trypanosoma cruzi/efectos de los fármacos , Trypanosoma cruzi/fisiología , Animales , Células Cultivadas , Enfermedad de Chagas/parasitología , Femenino , Interferón gamma/biosíntesis , Interleucina-10/biosíntesis , Macrófagos/metabolismo , Macrófagos/parasitología , Ratones , Ratones Noqueados , Receptores de Interferón/deficiencia , Receptores de Interferón/genética , Receptores de Interferón/metabolismo , Bazo/metabolismo , Bazo/parasitología , Factor de Necrosis Tumoral alfa/biosíntesisRESUMEN
The interplay between the immune and neuroendocrine systems is intense, with the cross-talk between these two systems increasing during stress circumstances. Stress events culminate with hormonal pathway activation elevating the plasma levels of glucocorticoids and catecholamines. The majority of the works evaluating the effects of stress hormones on immune cells have utilized in vivo animal models or clinical studies. This work evaluates the effects of norepinephrine, dopamine, dexamethasone, and the combination of norepinephrine and dexamethasone on cellular activation and expression of immunoregulatory cytokines and chemokines by human PBMC in vitro. Norepinephrine and dopamine increased lymphocyte activation accompanied by augmented Th1 and Th2 type cytokine production. Dexamethasone reduced cell activation and decreased frequencies of cytokine producing cells and chemokine production. The action of norepinephrine together with dexamethasone resulted in immunosupression. The observed effects of hormones and neurotransmitters on leukocyte subsets likely underlie their immunomodulatory action in vivo.
Asunto(s)
Citocinas/metabolismo , Dexametasona/farmacología , Dopamina/farmacología , Glucocorticoides/farmacología , Leucocitos/efectos de los fármacos , Monocitos/metabolismo , Norepinefrina/farmacología , Adulto , Células Cultivadas , Citocinas/antagonistas & inhibidores , Combinación de Medicamentos , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Humanos , Recuento de Leucocitos , Masculino , Monocitos/efectos de los fármacos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células TH1/metabolismo , Células Th2/metabolismoRESUMEN
CD4+ T cells can be divided into several distinct effector subpopulations, including Th1 and Th2. Human Th1 cells are essential for the establishment of cellular immune responses, whereas Th2 cells for immunoglobulin E synthesize by B cells and immunoregulation. This study determines the involvement of exogenously and endogenously produced T cell-derived cytokines during early differentiation of naive CD4+ T cells into Th1 and Th2 cells. Cytokine gene expression of purified experienced and naive CD4+T cells in the presence or absence of Th-directing cytokines and neutralizing anti-cytokine antibodies, was determined at early (20 and 40 h) time points, after in vitro activation. These studies demonstrated that: (1) endogenously produced, T cell-derived cytokines (interferon [IFN]-gamma and interleukin [IL]-4), play an important role in the regulation of early gene expression of Th2, but not Th1 type cytokines; (2) Th1-related cytokines, IFN-gamma, and IL-2, are preferentially expressed in cultures directed toward Th1, as compared with Th2; and (3) IL-4 and IFN-gamma showed early message expression in both differentiating populations, indicating a mixed profile of Th1 and Th2 cytokine production in early human Th cell development. These findings point to the critical role for endogenously produced cytokines in the early differentiation of human Th1 or Th2 cells.