RESUMO
BACKGROUND: Advanced-stage mycosis fungoides (MF)/Sézary syndrome (SS) patients are weighted by an unfavorable prognosis and share an unmet clinical need of effective treatments. International guidelines are available detailing treatment options for the different stages but without recommending treatments in any particular order due to lack of comparative trials. The aims of this second CLIC study were to retrospectively analyze the pattern of care worldwide for advanced-stage MF/SS patients, the distribution of treatments according to geographical areas (USA versus non-USA), and whether the heterogeneity of approaches has potential impact on survival. PATIENTS AND METHODS: This study included 853 patients from 21 specialist centers (14 European, 4 USA, 1 each Australian, Brazilian, and Japanese). RESULTS: Heterogeneity of treatment approaches was found, with up to 24 different modalities or combinations used as first-line and 36% of patients receiving four or more treatments. Stage IIB disease was most frequently treated by total-skin-electron-beam radiotherapy, bexarotene and gemcitabine; erythrodermic and SS patients by extracorporeal photochemotherapy, and stage IVA2 by polychemotherapy. Significant differences were found between USA and non-USA centers, with bexarotene, photopheresis and histone deacetylase inhibitors most frequently prescribed for first-line treatment in USA while phototherapy, interferon, chlorambucil and gemcitabine in non-USA centers. These differences did not significantly impact on survival. However, when considering death and therapy change as competing risk events and the impact of first treatment line on both events, both monochemotherapy (SHR = 2.07) and polychemotherapy (SHR = 1.69) showed elevated relative risks. CONCLUSION: This large multicenter retrospective study shows that there exist a large treatment heterogeneity in advanced MF/SS and differences between USA and non-USA centers but these were not related to survival, while our data reveal that chemotherapy as first treatment is associated with a higher risk of death and/or change of therapy and thus other therapeutic options should be preferable as first treatment approach.
Assuntos
Micose Fungoide/terapia , Síndrome de Sézary/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Brasil/epidemiologia , Criança , Europa (Continente)/epidemiologia , Feminino , Humanos , Japão/epidemiologia , Masculino , Oncologia/métodos , Oncologia/estatística & dados numéricos , Pessoa de Meia-Idade , Micose Fungoide/mortalidade , Micose Fungoide/patologia , Estadiamento de Neoplasias , Estudos Retrospectivos , Síndrome de Sézary/mortalidade , Síndrome de Sézary/patologia , Estados Unidos/epidemiologia , Adulto JovemRESUMO
γ-aminobutyric acid (GABA) receptors, responding to GABA positive allosteric modulators, are present in the freshwater polyp Hydra vulgaris (Cnidaria, Hydrozoa), one of the most primitive metazoans to develop a nervous system. We examined the occurrence and distribution of GABAA receptor subunits in Hydra tissues by western blot and immunohistochemistry. Antibodies against different GABAA receptor subunits were used in Hydra membrane preparations. Unique protein bands, inhibited by the specific peptide, appeared at 35, 60, â¼50 and â¼52 kDa in membranes incubated with α3, ß1, γ3 or δ antibodies, respectively. Immunohistochemical screening of whole mount Hydra preparations revealed diffuse immunoreactivity to α3, ß1 or γ3 antibodies in tentacles, hypostome, and upper part of the gastric region; immunoreactive fibers were also present in the lower peduncle. By contrast, δ antibodies revealed a strong labeling in the lower gastric region and peduncle, as well as in tentacles. Double labeling showed colocalization of α3/ß1, α3/γ3 and α3/δ immunoreactivity in granules or cells in tentacles and gastric region. In the peduncle, colocalization of both α3/ß1 and α3/γ3 immunoreactivity was found in fibers running horizontally above the foot. These data indicate that specific GABAA receptor subunits are present and differentially distributed in Hydra body regions. Subunit colocalization suggests that Hydra GABA receptors are heterologous multimers, possibly sub-serving different physiological activities.
Assuntos
Neurônios/metabolismo , Receptores de GABA-A/metabolismo , Ácido gama-Aminobutírico/metabolismo , Animais , Água Doce , Hydra , Imuno-Histoquímica/métodos , Subunidades Proteicas/metabolismoRESUMO
Exposure of developing female rats to estradiol during the perinatal period induced long-lasting dysregulation of gonadal axis and decreased cerebrocortical and plasma concentrations of allopregnanolone. We have now examined the effects of neonatal estradiol administration in female rats on hypothalamic allopregnanolone concentrations and on exploratory, affective, agonistic and sexual behaviors as well as social learning. A single administration of ß-estradiol 3-benzoate (EB, 10µg) on the day of birth resulted in a delay of vaginal opening, acyclicity and ovarian failure. These alterations were associated with a significant decrease in the concentrations of allopregnanolone in the hypothalamus at 21 and 60days, but not at 7days, after birth. Neonatal administration of EB also increased agonistic behaviors in adult rats, such as dominant behaviors and following of an ovariectomized intruder, while living attacks unaffected. EB-treated rats showed also an increase in anogenital investigation, associated with a drastic reduction in spontaneous and induced female sexual behaviors (receptivity and proceptivity). In contrast, neonatal administration of EB did not affect locomotor activity, anxiety- and mood-related behaviors, the social transmission of flavor preferences, and seizures sensitivity. These effects of estradiol suggest that it plays a major role in regulation of both the abundance of allopregnanolone and the expression of agonistic and sexual behaviors, while failing to influence affective behaviors and social learning. Thus, the pronounced and persistent decrease in hypothalamic allopregnanolone concentration may be related to the manifestation of agonistic and sexual behaviors.
Assuntos
Agressão/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Estradiol/farmacologia , Hipotálamo/efeitos dos fármacos , Pregnanolona/metabolismo , Comportamento Sexual Animal/efeitos dos fármacos , Agressão/fisiologia , Animais , Ansiedade/metabolismo , Comportamento Animal/fisiologia , Comportamento Exploratório/efeitos dos fármacos , Comportamento Exploratório/fisiologia , Feminino , Hipotálamo/metabolismo , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Ratos , Ratos Sprague-Dawley , Comportamento Sexual Animal/fisiologia , Comportamento SocialRESUMO
AIMS: Preoperative (chemo)radiotherapy followed by total mesorectal excision is the current standard of care for patients with locally advanced rectal cancer. The use of intensity-modulated radiotherapy (IMRT) for rectal cancer is increasing in the UK. However, the extent of IMRT implementation and current practice was not previously known. A national survey was commissioned to investigate the landscape of IMRT use for rectal cancer and to inform the development of national rectal cancer IMRT guidance. MATERIALS AND METHODS: A web-based survey was developed by the National Rectal Cancer IMRT Guidance working group in collaboration with the Royal College of Radiologists and disseminated to all UK radiotherapy centres. The survey enquired about the implementation of IMRT with a focus on the following aspects of the workflow: dose fractionation schedules and use of a boost; pre-treatment preparation and simulation; target volume/organ at risk definition; treatment planning and treatment verification. A descriptive statistical analysis was carried out. RESULTS: In total, 44 of 63 centres (70%) responded to the survey; 30/44 (68%) and 36/44 (82%) centres currently use IMRT to treat all patients and selected patients with rectal cancer, respectively. There was general agreement concerning several aspects of the IMRT workflow, including patient positioning, use of intravenous contrast and bladder protocols. Greater variation in practice was identified regarding rectal protocols; use of a boost to primary/nodal disease; target volume delineation; organ at risk delineation and dose constraints and treatment verification. Delineation of individual small bowel loops and daily volumetric treatment verification were considered potentially feasible by most centres. CONCLUSION: This survey identified that IMRT is already used to treat rectal cancer in many UK radiotherapy centres, but there is heterogeneity between centres in its implementation and practice. These results have been a valuable aid in framing the recommendations within the new National Rectal Cancer IMRT Guidance.
Assuntos
Radioterapia de Intensidade Modulada , Neoplasias Retais , Fracionamento da Dose de Radiação , Humanos , Dosagem Radioterapêutica , Neoplasias Retais/radioterapia , Reino UnidoRESUMO
Lung transplantation (LT) is a recognized procedure for selected patients with end-stage respiratory failure. We performed 123 LT, including 32 single lung, 84 double lung, and 7 heart-lung transplantations in 48 patients with chronic obstructive pulmonary disease (COPD), 13 patients with pulmonary hypertension (PH), 33 with cystic fibrosis (CF), and 29 with interstitial lung disease (ILD) between July 1990 and January 2008. Survival was compared for periods before and after December 2001. The mean age of patients was 44.4 years (range 16-66.5 years); 84 (69%) were men. Before LT, 1 second forced expiratory volume was 28.7% +/- 18.1% and PaCO(2) = 6.3 kPa. Fifty-five patients were on noninvasive ventilation. Cold ischemia time was 320 +/- 91 minutes. Cardiopulmonary bypass (CPB) was used in 77 patients (64%). There were 18 early surgical reinterventions, 8 extracorporeal membrane oxygenations, and 38 bronchial stent insertions among 206 at-risk bronchial sutures. Crude survivals were 69%, 58%, 41%, and 18% at 1, 2, 5, and 10 years, respectively. Comparing before (n = 70 with 15 CF) vs after December 2001 (n = 53 with 17 CF), survivals were 63% vs 78%, 51% vs 71%, and 33% vs 60% at 1, 2, and 5 years, respectively (P = .01) and for CF patients, 52% vs 100%, 52% vs 94%, and 25% vs 94% at 1, 2, and 5 years, respectively (P = .005). There was significant improvement in survival before and after 2001 in 123 LT and particularly among CF patients. Improvement in survival after LT may be related to the sum of numerous changes in our practice since December 2001, including the use of pulmonary rehabilitation pre-LT, extracellular pneumoplegia, statins, macrolides for chronic rejection, monitoring of Epstein-Barr blood load, changes in maintenance immunosuppressants, as well as position movement up the coordinator nurse and learning curve.
Assuntos
Sobrevivência de Enxerto/fisiologia , Transplante de Pulmão/fisiologia , Fibrose Cística/cirurgia , Feminino , Transplante de Coração-Pulmão/mortalidade , Transplante de Coração-Pulmão/fisiologia , Humanos , Hipertensão Pulmonar/cirurgia , Pneumopatias/cirurgia , Transplante de Pulmão/mortalidade , Masculino , Doença Pulmonar Obstrutiva Crônica/cirurgia , Estudos Retrospectivos , Análise de Sobrevida , SobreviventesRESUMO
INTRODUCTION: In 2015, the International Society for Heart and Lung Transplantation (ISHLT) published a consensus document for the selection of lung transplant candidates. In the absence of recent French recommendations, this guideline is useful in order to send lung transplant candidates to the transplantation centers and to list them for lung transplantation at the right time. BACKGROUND: The main indications for lung transplantation in adults are COPD and emphysema, idiopathic pulmonary fibrosis and interstitial diseases, cystic fibrosis and pulmonary arterial hypertension (PAH). The specific indications for each underlying disease as well as the general contraindications have been reviewed in 2015 by the ISHLT. For cystic fibrosis, the main factors are forced expiratory volume in one second, 6-MWD, PAH and clinical deterioration characterized by increased frequency of exacerbations; for emphysema progressive disease, the BODE score, hypercapnia and FEV1; for PAH progressive disease or the need of specific intravenous therapy and NYHA classification. Finally, the diagnosis of fibrosing interstitial lung disease is usually a sufficient indication for lung transplantation assessment. OUTLOOK AND CONCLUSION: These new recommendations, close to French practices, help clinicians to find the right time for referral of patients to transplantation centers. This is crucial for the prognosis of lung transplantation.
Assuntos
Transplante de Pulmão/métodos , Seleção de Pacientes , Adulto , Contraindicações , Fibrose Cística/epidemiologia , Fibrose Cística/terapia , França/epidemiologia , Transplante de Coração-Pulmão/efeitos adversos , Transplante de Coração-Pulmão/métodos , Transplante de Coração-Pulmão/normas , Humanos , Hipertensão Pulmonar/epidemiologia , Hipertensão Pulmonar/terapia , Fibrose Pulmonar Idiopática/epidemiologia , Fibrose Pulmonar Idiopática/terapia , Doenças Pulmonares Intersticiais/epidemiologia , Doenças Pulmonares Intersticiais/terapia , Transplante de Pulmão/efeitos adversos , Transplante de Pulmão/normas , Transplante de Pulmão/estatística & dados numéricos , Guias de Prática Clínica como Assunto/normas , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Doença Pulmonar Obstrutiva Crônica/terapia , Enfisema Pulmonar/epidemiologia , Enfisema Pulmonar/terapiaRESUMO
We have used a plasmid expressing a temperature-sensitive (ts) mutant of simian virus 40 (SV40) T antigen, stably transfected into 3T3 cells, to study the role of insulinlike growth factor 1 (IGF-1) and its receptor in T-antigen-mediated growth. While 3T3 cells do not grow in serum-free medium, in 1% serum, or with the sole addition of either platelet-derived growth factor (PDGF) or IGF-1, cells expressing the tsA T antigen (BALB 58 cells) grow at 34 degrees C in either PDGF or 1% serum but not in IGF-1. At the restrictive temperature (39.6 degrees C), these cells can only grow in 10% serum. We show that BALB 58 cells, at 34 degrees C, have a markedly increased expression of IGF-1 and IGF-1 mRNA and that their growth in 1% serum (at 34 degrees C) is inhibited by an antisense oligodeoxynucleotide to the IGF-1 receptor RNA. When this tsA plasmid is stably transfected into cells constitutively overexpressing the human IGF-1 receptor cDNA, the resulting cell lines show a constitutively phosphorylated IGF-1 receptor and grow in serum-free medium at 34 degrees C (but not at 39.6 degrees C). A functional SV40 T antigen also increases the expression of a plasmid in which the reporter luciferase gene is under the control of a rat IGF-1 promoter. We conclude (i) that the SV40 T antigen induces the expression of IGF-1 and IGF-1 mRNA, at least in part by a transcriptional mechanism, thus altering the growth factors requirements, and (ii) that, in BALB/c3t3 cells, the SV40 T antigen necessitates a functional IGF-1 receptor for its growth-stimulating effect in low serum (or PDGF).
Assuntos
Antígenos Transformantes de Poliomavirus/fisiologia , Fator de Crescimento Insulin-Like I/metabolismo , Receptor IGF Tipo 1/metabolismo , Células 3T3 , Animais , Sequência de Bases , Divisão Celular , Transformação Celular Viral , DNA , Camundongos , Dados de Sequência Molecular , Mapeamento por Restrição , TemperaturaRESUMO
OBJECTIVE: Resuscitative thoracotomy, a potentially life-saving procedure, is used exceptionally, and essentially for penetrating trauma. Most of the available literature is American while reports from Europe are sparse. We report our experience in a French level 1-trauma center. MATERIAL AND METHODS: Patient records (patient age, gender, mechanism of injury, indication for emergency thoracotomy, anatomic injuries, interventions and survival) for all patients who underwent emergency thoracotomy between January 2005 and December 2015 were analyzed. RESULTS: Twenty-two patients (19 males) underwent emergency thoracotomy. Median age was 27.5 (12-67) years. Twelve were performed for blunt trauma (55%) and 10 for penetrating injuries (45%). Thirteen patients presented with cardiac arrest, while nine had deep and refractory hypotension. Overall, survival was 32% (n=7). There were no survivors in the blunt trauma group while seven of ten with penetrating injuries survived. All patients presenting with cardiac arrest died. CONCLUSION: The survival rate in this French retrospective study was in accordance with the literature.
Assuntos
Causas de Morte , Ressuscitação/métodos , Toracotomia/métodos , Ferimentos e Lesões/mortalidade , Ferimentos Penetrantes/cirurgia , Adulto , Idoso , Estudos de Coortes , Tratamento de Emergência , Feminino , França , Humanos , Escala de Gravidade do Ferimento , Masculino , Pessoa de Meia-Idade , Ressuscitação/mortalidade , Estudos Retrospectivos , Taxa de Sobrevida , Toracotomia/mortalidade , Centros de Traumatologia , Resultado do Tratamento , Ferimentos e Lesões/diagnóstico , Ferimentos e Lesões/cirurgia , Ferimentos Penetrantes/diagnóstico , Ferimentos Penetrantes/mortalidade , Adulto JovemRESUMO
Alemtuzumab (anti-CD52; Campath-1H) is effective in fludarabine-refractory chronic lymphocytic leukemia (CLL), but is associated with infection and early onset neutropenia. To reduce toxicity, filgrastim (G-CSF) was administered concurrently with alemtuzumab. In total, 14 CLL patients (median age 59) with a median of 3.5 prior regimens (range 1--12) received i.v. alemtuzumab, stepped up from 3 to 30 mg the first week, then 30 mg thrice weekly for 12 weeks. Filgrastim 5 microg/kg was administered daily 5 days before and throughout alemtuzumab therapy. Six patients developed cytomegalovirus (CMV) reactivation 3--6 weeks into treatment; six patients developed fever, three neutropenia, and one pneumonia. The patient with CMV pneumonia died; ganciclovir cleared CMV in the other patients. Five patients developed early neutropenia (weeks 2--5). Four patients developed delayed neutropenia (weeks 10--13) unassociated with CMV reactivation. Nine patients ceased therapy because of infectious and hematologic toxicity. Five partial responses were noted, all in patients with lymph nodes>cm, lasting a median of 6.5 months (range 5--13). Filgrastim and alemtuzumab were given concurrently with manageable infusion toxicity and clinical activity, but the efficacy of this regimen was limited by delayed neutropenia of unclear etiology and CMV reactivation. Filgrastrim should not be administered prophylactically during alemtuzumab therapy outside clinical trials.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Idoso , Alemtuzumab , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Anticorpos Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Relação Dose-Resposta a Droga , Feminino , Filgrastim , Fator Estimulador de Colônias de Granulócitos/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Neutropenia/induzido quimicamente , Proteínas Recombinantes , Recidiva , Taxa de Sobrevida , Fatores de TempoRESUMO
The activation of the insulin-like growth factor 1 (IGF-1) receptor by its ligand plays a central role in the growth of most cell types. We have used the techniques of computational chemistry in order to design and synthesize several novel analogues of IGF-1. These analogues were able to inhibit the autophosphorylation of the IGF-1 receptor as well as the growth of several different cell types, including prostate carcinoma cells and SV40-transformed cells. Additionally, we have found that D-amino acid analogues of these peptides are apparently resistant to the proteolytic degradation that occurs in the presence of whole sera. Consequently, these analogues seem to show great potential both as probes of the structure/function activities of the IGF-1 signalling pathway and as novel clinical strategies in controlling abnormal cellular growth.
Assuntos
Divisão Celular/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/análogos & derivados , Fator de Crescimento Insulin-Like I/farmacologia , Modelos Químicos , Células 3T3 , Animais , Células Cultivadas , Fibroblastos , Humanos , Fator de Crescimento Insulin-Like I/química , Fator de Crescimento Insulin-Like I/metabolismo , Espectroscopia de Ressonância Magnética , Camundongos , Fosforilação , Conformação Proteica , Estrutura Terciária de Proteína , Receptor IGF Tipo 1/metabolismoRESUMO
The hemopoietic growth factor interleukin 3 (IL-3) supports the survival and proliferation of multipotent and committed progenitor cells in vitro. To elucidate the molecular mechanisms triggered by IL-3 we studied the expression of cell cycle-related genes in a recently established human IL-3-dependent clone (M-07e). No changes in the level of expression of early (c-myc), mid (ornithine decarboxylase), or mid-late G1 (p53, c-myb) cell cycle genes were detected after restoration of IL-3 in deprived cells. The fact that only late G1-S-phase genes [proliferating cell nuclear antigen (PCNA) thymidine kinase (TK), histone H3] are modulated by IL-3 suggests that this factor may control human cell proliferation by acting at the G1-S boundary.
Assuntos
Regulação da Expressão Gênica , Interleucina-3/farmacologia , Divisão Celular/efeitos dos fármacos , Linhagem Celular , DNA/biossíntese , Fase G1 , Genes myc , Humanos , Ornitina Descarboxilase/genética , RNA Mensageiro/análiseRESUMO
The protooncogene c-myb is the cellular equivalent of the viral transforming oncogene v-myb. When human c-myb is constitutively expressed in Balb/c3T3 cells it abrogates their absolute requirement for insulin-like growth factor 1 (IGF-1). We show now, in two different cell lines, that the constitutive expression of the protooncogene c-myb causes an increase in both IGF-1 and IGF = 1 receptor mRNA levels. This increase in mRNA levels is due, at least in part, to an increase in the rate of transcription since, by run-on assay, cells carrying the human c-myb cDNA show a 3-fold increase in transcriptional rates in comparison to the control parent cell lines. The increased expression of IGF-1 receptor mRNA also results in an increased number of IGF-1 binding sites per cell. Although some oncogenes have been described that are homologous to growth factors, or growth factor receptors, c-myb seems to represent a novel way of oncogene action inasmuch as it increases the expression of both a growth factor receptor and its ligand, thus establishing a quasi-autocrine mechanism which modifies the growth factor requirements of the cell and its growth regulation.
Assuntos
Regulação Neoplásica da Expressão Gênica , Fator de Crescimento Insulin-Like I/genética , Oncogenes , Proto-Oncogenes , RNA Mensageiro/genética , Receptores de Superfície Celular/genética , Transcrição Gênica , Transfecção , Células 3T3 , Animais , Sequência de Bases , Linhagem Celular , Cricetinae , Sondas de DNA , Humanos , Mesocricetus , Camundongos , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , Plasmídeos , Reação em Cadeia da Polimerase , RNA Mensageiro/metabolismo , Receptores de Somatomedina , Mapeamento por Restrição , Timidina Quinase/genéticaRESUMO
Women are more likely than men to suffer from anxiety disorders and major depression. These disorders share hyperresponsiveness to stress as an etiological factor. Thus, sex differences in brain arousal systems and their regulation by chronic stress may account for the increased vulnerability to these disorders in women. Social isolation is a model of early life stress that results in neurobiological alterations leading to increased anxiety-like and depressive-like behaviors. Here we investigated the sex difference in the effects of post-weaning social isolation on acute stress sensitivity and behavior in rats. In both sexes, social isolation at weaning reduced basal levels of the neuroactive steroid allopregnanolone in the brain and of corticosterone in plasma. Moreover, acute stress increased plasma corticosterone levels in both group-housed and socially isolated male and female rats; however this effect was greater in male than female rats subjected to social isolation. Intriguingly, group-housed female rats showed no change in plasma and brain levels of allopregnanolone after acute foot-shock stress. The absence of stress-induced effects on allopregnanolone synthesis might be due to the physiologically higher levels of this hormone in females vs. males. Accordingly, increasing allopregnanolone levels in male rats blunted the response to foot-shock stress in these animals. Socially isolated male, but not female, rats also display depressive-like behavior and increased hippocampal brain-derived neurotrophic factor (BDNF). The ovarian steroids could "buffer" the effect of this adverse experience in females on these parameters. Finally, the dexamethasone (DEX) suppression test indicated that the chronic stress associated with social isolation impairs feedback inhibition in both sexes in which an increase in the abundance of glucocorticoid receptors (GRs) in the hippocampus was found. Altogether, these results demonstrate that social isolation affects neuroendocrine reactivity to stress, plasticity and emotionality in a sexually dimorphic manner.
Assuntos
Sistema Hipotálamo-Hipofisário/fisiopatologia , Sistema Hipófise-Suprarrenal/fisiopatologia , Caracteres Sexuais , Isolamento Social , Estresse Psicológico/fisiopatologia , Animais , Comportamento Animal/fisiologia , Corticosterona/sangue , Ensaio de Imunoadsorção Enzimática , Feminino , Immunoblotting , Masculino , Pregnanolona/análise , Pregnanolona/metabolismo , Radioimunoensaio , Ratos , Ratos Sprague-DawleyRESUMO
Neuroactive steroids are endogenous neuromodulators synthesised in the brain that rapidly alter neuronal excitability by binding to membrane receptors, in addition to the regulation of gene expression via intracellular steroid receptors. Neuroactive steroids induce potent anxiolytic, antidepressant, anticonvulsant, sedative, analgesic and amnesic effects, mainly through interaction with the GABAA receptor. They also exert neuroprotective, neurotrophic and antiapoptotic effects in several animal models of neurodegenerative diseases. Neuroactive steroids regulate many physiological functions, such as the stress response, puberty, the ovarian cycle, pregnancy and reward. Their levels are altered in several neuropsychiatric and neurological diseases and both preclinical and clinical studies emphasise a therapeutic potential of neuroactive steroids for these diseases, whereby symptomatology ameliorates upon restoration of neuroactive steroid concentrations. However, direct administration of neuroactive steroids has several challenges, including pharmacokinetics, low bioavailability, addiction potential, safety and tolerability, which limit its therapeutic use. Therefore, modulation of neurosteroidogenesis to restore the altered endogenous neuroactive steroid tone may represent a better therapeutic approach. This review summarises recent approaches that target the neuroactive steroid biosynthetic pathway at different levels aiming to promote neurosteroidogenesis. These include modulation of neurosteroidogenesis through ligands of the translocator protein 18 kDa and the pregnane xenobiotic receptor, as well as targeting of specific neurosteroidogenic enzymes such as 17ß-hydroxysteroid dehydrogenase type 10 or P450 side chain cleavage. Enhanced neurosteroidogenesis through these targets may be beneficial not only for neurodegenerative diseases, such as Alzheimer's disease and age-related dementia, but also for neuropsychiatric diseases, including alcohol use disorders.
Assuntos
Neurotransmissores/biossíntese , Neurotransmissores/uso terapêutico , Pesquisa Translacional Biomédica , 17-Hidroxiesteroide Desidrogenases/metabolismo , Alcoolismo/tratamento farmacológico , Doença de Alzheimer/tratamento farmacológico , Humanos , Receptor de Pregnano X , Receptores de GABA/metabolismo , Receptores de Esteroides/metabolismoRESUMO
We have investigated the role of the insulin-like growth factor one (IGF1) receptor and its relationship to the proto-oncogene c-myb in the growth of two types of hemopoietic cells: mitogen-stimulated human peripheral blood mononuclear cells and a human promyelocytic cell line (HL-60). Using the antisense strategy and the reverse transcriptase polymerase chain reaction (RT-PCR), we show that expression of the IGF1 receptor is required for the entry into S phase of both stimulated lymphocytes and HL-60 cells. The inhibition of DNA synthesis by antisense oligomers to the IGF1 receptor RNA is accompanied by an inhibition of the expression of the mRNA for a DNA synthesis gene, proliferating cell nuclear antigen (PCNA), the co-factor of DNA polymerase delta. Inhibition of c-myb expression results in a decrease in IGF1 receptor mRNA levels; on the other hand, inhibition of IGF1 receptor expression has no effect on c-myb mRNA levels. A tentative temporal relationship between these three genes (c-myb, IGF1 receptor, PCNA) is proposed.
Assuntos
Leucemia Promielocítica Aguda/patologia , Leucócitos Mononucleares/fisiologia , Receptor IGF Tipo 1/fisiologia , Sequência de Bases , Divisão Celular , DNA/biossíntese , Humanos , Dados de Sequência Molecular , Proteínas Nucleares/genética , Oligonucleotídeos Antissenso/farmacologia , Oncogenes , Antígeno Nuclear de Célula em Proliferação , Proto-Oncogene Mas , RNA Mensageiro/análise , Receptor IGF Tipo 1/análise , Receptor IGF Tipo 1/genética , Acetato de Tetradecanoilforbol/farmacologia , Células Tumorais CultivadasRESUMO
Balb/c 3T3 cells transformed by the tsA58 temperature-sensitive (ts) mutant of SV40 large T antigen, BalbA58 cells, grow in 1% serum at the permissive temperature of 34 degrees C but fail to grow at the restrictive temperature of 39.6 degrees C. Although incapable of growing, BalbA58 cells, in low serum at 39.6 degrees C, still synthesize DNA and tend to accumulate in the G2 phase of the cell cycle. Growth in 1% serum at 39.6 degrees C resumes if BalbA58 cells are treated with insulin-like growth factor I (IGF-I). By using cells overexpressing the IGF-I receptor, and cells with a targeted disruption of the IGF-I receptor genes, we show that: 1) the activation of the IGP-I receptor by its ligand(s) plays a major role in the ability of the SV40 large T antigen to promote growth in low serum; and 2) the IGF-I receptor plays a role in the progression of cells not only through G1, but also through the S and G2 phases of the cell cycle. These findings, together with other recent findings from the literature, suggest that one of the mechanisms by which oncogenes and tumor suppressor genes regulate cell growth is through the modulation of growth factors and their receptors.
Assuntos
Antígenos Transformantes de Poliomavirus/farmacologia , Transformação Celular Viral , Fator de Crescimento Insulin-Like I/farmacologia , Receptores de Somatomedina/fisiologia , Células 3T3 , Animais , Antígenos Transformantes de Poliomavirus/genética , Divisão Celular , Linhagem Celular , DNA/biossíntese , Fator de Crescimento Insulin-Like I/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Mutação , TemperaturaRESUMO
The promoter of the Insulin-like growth factor I (IGF-I) gene is activated by the Simian Virus 40 large T antigen (SVLT), and one of the elements responding to SVLT activation has been localized to a short 124 bp immediately upstream of the first initiation of transcription site. This short promoter contains an E2F binding site, that, in gel shifts, binds a protein complex, but only when the promoter activity is reduced or absent. A mutation in the E2F binding site deregulates the activity of the promoter, which becomes active even in those conditions in which the wild type promoter is inactive. By using antibodies in gel retardation analyses, we can show that the different protein complexes include, at least, the following proteins: E2F, cyclin A and p107. We conclude that the short IGF-I promoter is negatively regulated by an E2F binding site that complexes with several proteins. Our data suggest that disaggregation of these complexes by the action of SVLT (or other activators) increases expression from the promoter, thus establishing a link between the regulation of cell proliferation by growth factors and the E2F-associated proteins.