RESUMO
BACKGROUND: Comprehensive next-generation sequencing is widely used for precision oncology and precision prevention approaches. We aimed to determine the yield of actionable gene variants, the capacity to uncover hereditary predisposition and liquid biopsy appropriateness instead of, or in addition to, tumor tissue analysis, in a real-world cohort of cancer patients, who may benefit the most from comprehensive genomic profiling. METHODS: Seventy-eight matched germline/tumor tissue/liquid biopsy DNA and RNA samples were profiled using the Hereditary Cancer Panel (germline) and the TruSight Oncology 500 panel (tumor tissue/cfDNA) from 23 patients consecutively enrolled at our center according to at least one of the following criteria: no available therapeutic options; long responding patients potentially fit for other therapies; rare tumor; suspected hereditary cancer; primary cancer with high metastatic potential; tumor of unknown primary origin. Variants were annotated for OncoKB and AMP/ASCO/CAP classification. RESULTS: The overall yield of actionable somatic and germline variants was 57% (13/23 patients), and 43.5%, excluding variants previously identified by somatic or germline routine testing. The accuracy of tumor/cfDNA germline-focused analysis was demonstrated by overlapping results of germline testing. Five germline variants in BRCA1, VHL, CHEK1, ATM genes would have been missed without extended genomic profiling. A previously undetected BRAF p.V600E mutation was emblematic of the clinical utility of this approach in a patient with a liver undifferentiated embryonal sarcoma responsive to BRAF/MEK inhibition. CONCLUSIONS: Our study confirms the clinical relevance of performing extended parallel tumor DNA and cfDNA testing to broaden therapeutic options, to longitudinally monitor cfDNA during patient treatment, and to uncover possible hereditary predisposition following tumor sequencing in patient care.
Assuntos
Genômica , Mutação em Linhagem Germinativa , Neoplasias , Humanos , Feminino , Biópsia Líquida , Neoplasias/genética , Neoplasias/patologia , Masculino , Pessoa de Meia-Idade , Estudos de Coortes , Mutação em Linhagem Germinativa/genética , Genômica/métodos , Adulto , Idoso , Células Germinativas/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Predisposição Genética para DoençaRESUMO
BACKGROUND: The outbreak of Coronavirus disease 2019 (COVID-19) made imperative the use of protective devices as a source control tool. As there is no definite antiviral treatment and effective vaccine, the only efficient means of protecting and mitigating infectious contagion has been the use of personal protective equipment, especially by healthcare workers. However, masks affect the humidification process of inhaled air, possibly leading to a basal inflammatory state of the upper airways. STUDY DESIGN: This is a single-center observational study conducted at the University Hospital of Catania from April 1, 2020, to June 31, 2020. METHODS: We analyzed the role of protective masks on the elimination of upper airways complaints in healthcare workers of the University Hospital of Catania. We evaluated 277 subjects through a self-administered 17 item questionnaire based on respiratory, work performance and health-related quality of life domains. RESULTS: A higher prevalence of nasal and ocular symptoms, perceived reduced work performance, difficulty in concentrating, and sleep disorders were found. After two weeks adhering to a list of good practices that we recommended, significant reversibility of the symptoms investigated and work performance enhancement were observed. CONCLUSIONS: Despite clinical complaints related to personal protective equipment, effective amelioration through usage rules is easily obtained. Given the essential use of protective masks, healthcare workers have to adhere to appropriate work and safety prevention rules.
Assuntos
COVID-19/prevenção & controle , Pessoal de Saúde , Máscaras/efeitos adversos , Doenças Profissionais/etiologia , Qualidade de Vida , Desempenho Profissional , Adulto , COVID-19/transmissão , Oftalmopatias/etiologia , Oftalmopatias/prevenção & controle , Feminino , Fidelidade a Diretrizes , Humanos , Pneumopatias/etiologia , Pneumopatias/prevenção & controle , Masculino , Máscaras/normas , Pessoa de Meia-Idade , Doenças Nasais/etiologia , Doenças Nasais/prevenção & controle , Doenças Profissionais/prevenção & controle , Equipamento de Proteção Individual/normas , Inquéritos e QuestionáriosRESUMO
Inflammation represents an important factor leading to metabolic imbalance within the intervertebral disc (IVD), conducive to degenerative changes. Therefore, a thorough knowledge of the IVD and endplate (EP) cell behaviour in such pathological environments is essential when designing regenerative therapeutic strategies. The present study aimed at assessing the molecular response of the IVD constitutive nucleus pulposus (NPCs)-, annulus fibrosus (AFCs)- and endplate (EPCs)-derived cells to interleukin (IL)-1ß treatment, through large-scale, high-throughput microarray and protein analysis, identifying the differentially expressed genes and released proteins. Overall, the inflammatory stimulus downregulated stemness genes while upregulating pro-inflammatory, pro-angiogenic and catabolic genes, including matrix metalloproteases, which were not balanced by a concomitant upregulation of their inhibitors. Upregulation of anti-inflammatory and anabolic tumour necrosis factor inducible gene 6 protein (TNFAIP6), of IL-1 receptor antagonist (IL-1Ra) (at gene and protein levels) and of trophic insulin-like growth factor 1 (IGF1) was also observed in all cell types; IGF1 particularly in AFCs. An overall inhibitory effect of tumour necrosis factor alpha (TNFα) signal was observed in all cell types; however, EPCs showed the strongest anti-inflammatory behaviour. AFCs and EPCs shared the ability to limit the activation of the signalling mediated by specific chemokines. AFCs showed a slightly senescent attitude, with a downregulation of genes related to DNA repair or pro-mitosis. Results allowed for the identification of specific molecular targets in IVD and EP cells that respond to an inflammatory environment. Such targets can be either silenced (when pathological targets) or stimulated to counteract the inflammation.
Assuntos
Inflamação/patologia , Interleucina-1beta/farmacologia , Degeneração do Disco Intervertebral/patologia , Disco Intervertebral/patologia , Placa Motora/patologia , Análise por Conglomerados , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Inflamação/genética , Disco Intervertebral/efeitos dos fármacos , Degeneração do Disco Intervertebral/genética , Masculino , Metaloproteinases da Matriz/metabolismo , Pessoa de Meia-Idade , Placa Motora/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Inibidores Teciduais de Metaloproteinases/metabolismoRESUMO
Degenerative processes of the intervertebral disc (IVD) and cartilaginous endplate lead to chronic spine pathologies. Several studies speculated on the intrinsic regenerative capacity of degenerated IVD related to the presence of local mesenchymal progenitors. However, a complete characterisation of the resident IVD cell populations, particularly that isolated from the endplate, is lacking. The purpose of the present study was to characterise the gene expression profiles of human nucleus pulposus (NPCs), annulus fibrosus (AFCs) and endplate (EPCs) cells, setting the basis for future studies aimed at identifying the most promising cells for regenerative purposes. Cells isolated from NP, AF and EP were analysed after in vitro expansion for their stemness ability, immunophenotype and gene profiles by large-scale microarray analysis. The three cell populations shared a similar clonogenic, adipogenic and osteogenic potential, as well as an immunophenotype with a pattern resembling that of mesenchymal stem cells. NPCs maintained the greatest chondrogenic potential and shared with EPCs the loss of proliferation capability during expansion. The largest number of selectively highly expressed stemness, chondrogenic/tissue-specific and surface genes was found in AFCs, thus representing the most promising source of tissue-specific expanded cells for the treatment of IVD degeneration.
Assuntos
Anel Fibroso/patologia , Degeneração do Disco Intervertebral/patologia , Degeneração do Disco Intervertebral/terapia , Disco Intervertebral/patologia , Placa Motora/patologia , Biomarcadores/metabolismo , Proliferação de Células , Senescência Celular/genética , Condrogênese/genética , Células Clonais , Feminino , Regulação da Expressão Gênica , Humanos , Imunofenotipagem , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Masculino , Pessoa de Meia-Idade , Núcleo Pulposo/patologia , Especificidade de Órgãos , RNA/isolamento & purificação , Telômero/genéticaRESUMO
BACKGROUND: CEA, CYFRA21-1 and NSE are tumor markers used for monitoring the response to chemotherapy in advanced adenocarcinoma, squamous cell carcinoma and small-cell lung cancer, respectively. Their role in cancer immunotherapy needs to be elucidated. METHODS: Patients with advanced non-small cell lung cancer (NSCLC) were treated with nivolumab 3 mg/kg every 2 weeks within the Italian Nivolumab Expanded Access Program. Blood samples were collected at baseline, at each cycle up to cycle 5 and then every two cycles until patient's withdrawn from the study. All patients underwent a CT-scan after every 4 cycles of treatment and responses were classified according to RECIST 1.1. The biomarkers serum levels were measured with a chemiluminescent microparticle immunoassay for CEA and with an immuno radiometric assay for CYFRA21-1 and NSE. The markers values at baseline and after 4 cycles were used to analyze the relationship between their variation over baseline and the tumor response, evaluated as disease control rate (DCR: CR + PR + SD), and survival (PFS and OS). RESULTS: A total of 70 patients were evaluable for the analysis. Overall, a disease control was obtained in 24 patients (35.8%, 4 PR + 20 SD). After 4 cycles of nivolumab a CEA or CYFRA21-1 reduction ≥ 20% over the baseline was significantly associated with DCR (CEA, p = 0.021; CYFRA21-1, p < 0.001), PFS (CEA, p = 0.028; CYFRA21-1, p < 0.001) and OS (CEA, p = 0.026; CYFRA21-1, p = 0.019). Multivariate analysis confirmed the ability of CYFRA21-1 reduction ≥ 20% to predict DCR (p = 0.002) and PFS (p < 0.001). CONCLUSION: The reduction in serum level of CYFRA21-1 or CEA might be a reliable biomarker to predict immunotherapy efficacy in NSCLC patients. NSE was not significant for monitoring the efficacy of nivolumab.
Assuntos
Antígenos de Neoplasias/sangue , Antígeno Carcinoembrionário/sangue , Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Queratina-19/sangue , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/tratamento farmacológico , Nivolumabe/uso terapêutico , Fosfopiruvato Hidratase/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/sangue , Carcinoma Pulmonar de Células não Pequenas/patologia , Intervalo Livre de Doença , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de NeoplasiasRESUMO
Preclinical studies have suggested that combining cytotoxic agents with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) to treat EGFR-mutated tumors may increase their inhibitory effect depending on the order of drug administration. The antitumor efficacy of different treatment sequences using vinorelbine (VNB) and gefitinib (GEF) was investigated both in vitro and in vivo in non-small cell lung cancer (NSCLC) cell lines with the rationale of potentially translating these findings into the clinical setting. The EGFR-wild-type A549 and the EGFR-mutated (exon 21 L858R/exon 20 T790M) H1975 cell lines were treated as follows: GEF followed by VNB, VNB followed by GEF and the two drugs applied individually or concurrently. Results in vitro demonstrated that the sequence of VNB followed by GEF was significantly more active than single-agent treatments. The expression of activated EGFR and its downstream pathway genes indicated that the increased cytotoxic effect of the VNB and GEF treatment sequence was accompanied by inhibition of EGFR, AKT and ERK1/2. Moreover, the increased inhibition of tumor growth after treatment with VNB followed by GEF was also confirmed in CD1-nude mice that were xenotransplanted with H1975 cells (p < 0.0001). This effect was paralleled by a corresponding decrease in cancer glucose consumption, as assessed by micro-positron emission tomography scans (p < 0.05). These preclinical findings in NSCLC cell lines, which are poorly responsive to EGFR-TKIs, demonstrated that the sequential treatment of VNB followed by GEF induced a significant antitumor effect, which supports the translation of this treatment schedule into a clinical setting.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Linhagem Celular Tumoral , Esquema de Medicação , Resistencia a Medicamentos Antineoplásicos , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Feminino , Fluordesoxiglucose F18/farmacocinética , Gefitinibe , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Camundongos Nus , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/administração & dosagem , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Transdução de Sinais , Vimblastina/administração & dosagem , Vimblastina/análogos & derivados , Vinorelbina , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Malignant mesothelioma (MM) is an aggressive tumor, mainly derived from the pleura, which is predominantly associated with exposure to asbestos fibers. The prognosis of MM patients is particularly severe, with a median survival of approximately 9-12 months and latency between exposure and diagnosis ranging from 20-50 years (median 30 years). Emerging evidence has demonstrated that tumor aggressiveness is associated with genome and gene expression abnormalities; therefore, several studies have recently focused on the role of microRNAs (miRNAs) in MM tumorigenesis. miRNAs are small non-protein coding single-stranded RNAs (17-22 nucleotides) involved in numerous cellular processes that negatively regulate gene expression by modulating the expression of downstream target genes. miRNAs are often deregulated in cancer; in particular, the differential miRNA expression profiles of MM cells compared to unaffected mesothelial cells have suggested potential roles of miRNAs as either oncogenes or tumor suppressor genes in MM oncogenesis. In this review, the mechanism of MM carcinogenesis was evaluated through the analysis of the published miRNA expression data. The roles of miRNAs as diagnostic biomarkers and prognostic factors for potential therapeutic strategies will be presented and discussed.
Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Mesotelioma/genética , MicroRNAs/genética , Animais , Biomarcadores Tumorais/genética , Humanos , Pulmão/metabolismo , Pulmão/patologia , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia , Mesotelioma/diagnóstico , Mesotelioma/terapia , Mesotelioma Maligno , Oncogenes , PrognósticoRESUMO
BACKGROUND: To investigate a novel velopharyngeal squeeze maneuver (VPSM) and novel endoscopic pharyngeal contraction grade (EPCG) scale for the evaluation of pharyngeal motor function. METHODS: During endoscopic examination of 77 post-irradiated nasopharyngeal carcinoma patients and control subjects, VPSM was rated and lateral pharyngeal wall movement graded with EPCG scale during swallowing. Pharyngeal constriction ratio (PCR) measured by videofluoroscopy was used for correlation. RESULTS: VPSM and EPCG scale showed almost perfect intra-rater and inter-rater reliability (Kappa: >0.90). VPSM was present in 61% of patients suggesting good pharyngeal motor function. VPSM was predictive of EPCG scale (Wald statistic = 29.99, p < 0.001). EPCG scale also correlated strongly with PCR (r: 0.812) and was predictive for aspiration (odds ratio: 22.14 [95% CI 5.01-97.89, p < 0.001]). CONCLUSIONS: VPSM and EPCG scale are two novel tools to assess pharyngeal motor function, and both correlate well with pharyngeal contractility and aspiration.
Assuntos
Transtornos de Deglutição , Neoplasias Nasofaríngeas , Deglutição , Transtornos de Deglutição/diagnóstico , Transtornos de Deglutição/etiologia , Humanos , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/radioterapia , Faringe/diagnóstico por imagem , Reprodutibilidade dos TestesRESUMO
PURPOSE: Since the role of resistin was evaluated only in patients with non-small cell lung cancer (NSCLC) not treated with immunotherapy, we aimed to evaluate levels of resistin during immunotherapy (nivolumab) and its prognostic role with regard to OS. METHODS/PATIENTS: From a cohort of 78 patients with advanced NSCLC enrolled in a prospective study at Ospedale Policlinico San Martino in Genoa (Italy), 43 patients have been considered for this sub-analysis because of the availability of samples. Before and during nivolumab administration, clinical information and blood samples were collected and resistin, matrix metalloproteinase (MMP)-8, MMP-9, and myeloperoxidase were evaluated by enzyme-linked immunosorbent assay (ELISA). RESULTS: Median age was 71 with a prevalence of males and former smokers. Median resistin levels presented a peak at cycle 2 and then dropped down until the last cycle. Resistin correlated with all neutrophil degranulation products at cycle 1 (except for MMP-9) and at cycle 2 as well as with white blood cells and neutrophils. By a ROC curve analysis, a resistin value at cycle 2 of 19 ng/mL was tested as the best cut-off point for OS. Kaplan-Meier analysis demonstrated that patients above the resistin cut-off experienced a reduced OS (median OS 242.5 vs. 470 days, p = 0.0073), as confirmed by Cox proportional hazards regression analysis. CONCLUSIONS: Resistin levels > 19 ng/mL at the time of the second cycle of nivolumab treatment independently predict a reduced OS in patients with advanced NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/sangue , Neoplasias Pulmonares/sangue , Nivolumabe/uso terapêutico , Resistina/sangue , Idoso , Antineoplásicos Imunológicos/uso terapêutico , Biomarcadores Tumorais/sangue , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Neutrófilos/citologia , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida , Resultado do TratamentoRESUMO
Calcium imaging techniques were used to obtain a clear although indirect evidence about the distribution of functional glutamate receptors of NMDA and non-NMDA type in cultured hippocampal neurons during establishment of polarity and synaptogenesis. Glutamate receptors were expressed and were already functional as early as one day after plating. At this stage NMDA and non-NMDA receptors were distributed in all plasmalemmal areas. During the establishment of neuronal polarity, responses to either types of glutamate receptors became restricted to the soma and dendrites. Compartmentalization of glutamate receptors occurred at stages of development when synaptic vesicles were already fully segregated to the axon. Formation of synapses was accompanied by a further redistribution of receptors, which segregated to synapse-enriched portions of dendrites. Receptor compartmentalization and dendritic redistribution as well as accumulation of synaptic vesicles at synaptic sites occurred also in neurons cultured in the presence of either the sodium channel blocker tetrodotoxin or glutamate receptor antagonists. These results indicate that signals generated by neuronal electrical activity or receptor activation are not involved in the establishment of neuronal polarity and synaptogenesis.
Assuntos
Cálcio/fisiologia , Polaridade Celular/fisiologia , Neurônios/citologia , Receptores de Glutamato/metabolismo , Transdução de Sinais/fisiologia , Sinapses/fisiologia , Animais , Cálcio/metabolismo , Células Cultivadas , Antagonistas de Aminoácidos Excitatórios , Hipocampo/citologia , Hipocampo/embriologia , N-Metilaspartato/farmacologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/ultraestrutura , Cloreto de Potássio/farmacologia , Ratos , Receptores de Glutamato/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/metabolismo , Tetrodotoxina/farmacologiaRESUMO
During CNS development neurons undergo directional migration to achieve their adult localizations. To study neuronal migration, we used a model cell line of immortalized murine neurons (gonadotropin-releasing hormone expressing neurons; GN11), enriched with caveolins and caveolae invaginations that show in vitro chemotaxis upon serum exposure. Cholesterol depletion with methyl-beta-cyclodextrin induced the loss of caveolae and the inhibition of chemotaxis, thus suggesting that GN11 migration depends upon the structural integrity of caveolae. Polarization of proteins and organelles is a hallmark of cell migration. Accordingly, GN11 cells transmigrating through filter pores exhibited a polarized distribution of caveolin-1 isoform (cav-1) in the leading processes. In contrast, during two-dimensional migration cav-1 and caveolae polarized at the trailing edge. As caveolae are enriched with signaling molecules, we suggest that asymmetrical localization of caveolae may spatially orient GN11 neurons to incoming migratory signals thereby transducing them into directional migration.
Assuntos
Cavéolas/metabolismo , Caveolinas/metabolismo , Movimento Celular/fisiologia , Neurônios/fisiologia , Animais , Linhagem Celular Transformada , Movimento Celular/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Quimiotaxia/fisiologia , Colesterol/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Indóis , Camundongos , Microscopia Eletrônica de Transmissão/métodos , Neurônios/efeitos dos fármacos , Neurônios/ultraestrutura , Sais de Tetrazólio , Tiazóis , beta-Ciclodextrinas/farmacologiaRESUMO
INTRODUCTION: Vinflunine belongs to the class of vinca alkaloids and acts by disrupting the microtubule dynamics during cell cycle; this agent is currently available for previously treated advanced transitional cell carcinoma in Europe. The aim of this invited review is to evaluate the potential role of vinflunine for the treatment of non-small cell lung cancer (NSCLC). Areas covered: The potential role of vinflunine in NSCLC is discussed on the basis of the available data, including full papers and meeting abstracts. Relevant preclinical studies describing the pharmacological properties of vinflunine are also included. The review also summarizes clinical studies, including phase I trials involving NSCLC among other tumors as well as phase II/III trials specifically addressing this malignancy. Additionally, the safety profile and the current regulatory status of vinflunine is discussed. Expert opinion: Vinflunine is active as single agent and as part of platinum-based combinations in NSCLC. It results non-inferior to docetaxel in a randomized phase III trial including previously treated NSCLC patients; additionally, its safety profile is generally considered manageable. Ultimately, further studies are needed to confirm the role of vinflunine in NSCLC, in consideration of the evolving evidence regarding targeted therapies and immune check-point inhibitors.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Vimblastina/análogos & derivados , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Humanos , Neoplasias Pulmonares/patologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Vimblastina/administração & dosagem , Vimblastina/efeitos adversos , Vimblastina/farmacologiaRESUMO
Recycling synaptic vesicles are already present in isolated axons of developing neurons (Matteoli et al., Zakharenko et al., 1999). This vesicle recycling is distinct from the vesicular traffic implicated in axon outgrowth. Formation of synaptic contacts coincides with a clustering of synaptic vesicles at the contact site and with a downregulation of their basal rate of exo-endocytosis (Kraszewski et al, 1995; Coco et al., 1998) We report here that tetanus toxin-mediated cleavage of synaptobrevin/vesicle-associated membrane protein (VAMP2), previously shown not to affect axon outgrowth, also does not inhibit synaptic vesicle exocytosis in isolated axons, despite its potent blocking effect on their exocytosis at synapses. This differential effect of tetanus toxin could be seen even on different branches of a same neuron. In contrast, botulinum toxins A and E [which cleave synaptosome-associated protein of 25 kDa. (SNAP-25)] and F (which cleaves synaptobrevin/VAMP1 and 2) blocked synaptic vesicle exocytosis both in isolated axons and at synapses, strongly suggesting that this process is dependent on "classical" synaptic SNAP receptor (SNARE) complexes both before and after synaptogenesis. A tetanus toxin-resistant form of synaptic vesicle recycling, which proceeds in the absence of external stimuli and is sensitive to botulinum toxin F, E, and A, persists at mature synapses. These data suggest the involvement of a tetanus toxin-resistant, but botulinum F-sensitive, isoform of synaptobrevin/VAMP in synaptic vesicle exocytosis before synapse formation and the partial persistence of this form of exocytosis at mature synaptic contacts.
Assuntos
Axônios/efeitos dos fármacos , Exocitose/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Vesículas Sinápticas/efeitos dos fármacos , Toxina Tetânica/farmacologia , Proteínas de Transporte Vesicular , Animais , Axônios/ultraestrutura , Células Cultivadas , Senescência Celular , Hipocampo/efeitos dos fármacos , Hipocampo/ultraestrutura , Proteínas de Membrana/efeitos dos fármacos , Proteínas do Tecido Nervoso/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/ultraestrutura , Ratos , Proteínas SNARE , Sinapses/ultraestruturaRESUMO
Outgrowth of the dendrites and the axon is the basis of the establishment of the neuronal shape, and it requires addition of new membrane to both growing processes. It is not yet clear whether one or two exocytotic pathways are responsible for the respective outgrowth of axons and dendrites. We have previously shown that tetanus neurotoxin-insensitive vesicle-associated membrane protein (TI-VAMP) defines a novel network of tubulovesicular structures present both at the leading edge of elongating dendrites and axons of immature hippocampal neurons developing in primary culture and that TI-VAMP is an essential protein for neurite outgrowth in PC12 cells. Here we show that the expression of the N-terminal domain of TI-VAMP inhibits the outgrowth of both dendrites and axons in neurons in primary culture. This effect is more prominent at the earliest stages of the development of neurons in vitro. Expression of the N-terminal domain deleted form of TI-VAMP has the opposite effect. This constitutively active form of TI-VAMP localizes as the endogenous protein, particularly concentrating at the leading edge of growing axons. Our results suggest that a common exocytotic mechanism that relies on TI-VAMP mediates both axonal and dendritic outgrowth in developing neurons.
Assuntos
Axônios/fisiologia , Dendritos/fisiologia , Exocitose/fisiologia , Neurônios/metabolismo , Animais , Autoantígenos , Encéfalo/citologia , Encéfalo/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Calreticulina , Células Cultivadas , Eletroporação , Endocitose/fisiologia , Expressão Gênica , Proteínas de Fluorescência Verde , Técnicas In Vitro , Proteínas Luminescentes/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Neurônios/citologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estrutura Terciária de Proteína/fisiologia , Proteínas Qa-SNARE , Proteínas R-SNARE , Ratos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Ribonucleoproteínas/metabolismo , TransfecçãoRESUMO
During development of neuronal circuits, presynaptic and postsynaptic functions are adjusted in concert, to optimize interneuronal signaling. We have investigated whether activation of glutamate receptors affects presynaptic function during synapse formation, when constitutive synaptic vesicle recycling is downregulated. Using primary cultures of hippocampal neurons as a model system, we have found that chronic exposure to both NMDA and non-NMDA glutamate receptor blockers during synaptogenesis produces an increase in miniature EPSC (mEPSC) frequency, with no significant changes in mEPSC amplitude or in the number of synapses. Enhanced synaptic vesicle recycling, selectively in glutamatergic nerve terminals, was confirmed by the increased uptake of antibodies directed against the lumenal domain of synaptotagmin. No increased uptake was detected in neuronal cultures grown in the chronic presence of TTX, speaking against an indirect effect caused by decreased electrical activity. Enhanced mEPSC frequency correlated with a reduction of synaptophysin-synaptobrevin-vesicle-associated membrane protein 2 (VAMP2) complexes detectable by immunoprecipitation. Intracellular perfusion with a peptide that inhibits the binding of synaptophysin to synaptobrevin-VAMP2 induced a remarkable increase of mEPSC frequency in control but not in glutamate receptor blocker-treated neurons. These findings suggest that activation of glutamate receptors plays a role in the downregulation of the basal rate of synaptic vesicle recycling that accompanies synapse formation. They also suggest that one of the mechanisms through which this downregulation is achieved is an increased interaction of synaptophysin with synaptobrevin-VAMP2.
Assuntos
Proteínas de Membrana/metabolismo , Terminações Pré-Sinápticas/metabolismo , Receptores de Glutamato/metabolismo , Sinaptofisina/metabolismo , Animais , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Endocitose/fisiologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Exocitose/efeitos dos fármacos , Exocitose/fisiologia , Hipocampo , Substâncias Macromoleculares , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Técnicas de Patch-Clamp , Ligação Proteica/efeitos dos fármacos , Proteínas R-SNARE , Ratos , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Transmissão Sináptica/efeitos dos fármacos , Vesículas Sinápticas/metabolismo , Tetrodotoxina/farmacologiaRESUMO
The clostridial neurotoxin-insensitive soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptors, tetanus neurotoxin-insensitive (TI)-vesicle-associated membrane protein (VAMP)/VAMP7, SNAP23, and syntaxin 3 have recently been implicated in transport of exocytotic vesicles to the apical plasma membrane of epithelial cells. This pathway had been shown previously to be insensitive to tetanus neurotoxin and botulinum neurotoxin F. TI-VAMP/VAMP7 is also a good candidate to be implicated in an exocytotic pathway involved in neurite outgrowth because tetanus neurotoxin does not inhibit this process in conditions in which it abolishes neurotransmitter release. We have now found that TI-VAMP/VAMP7 has a widespread distribution in the adult rat brain in which its localization strikingly differs from that of nerve terminal markers. TI-VAMP/VAMP7 does not enrich in synaptic vesicles nor in large dense-core granules but is associated with light membranes. In hippocampal neurons developing in vitro, TI-VAMP/VAMP7 localizes to vesicles in the axonal and dendritic outgrowths and concentrates into the leading edge of the growth cone, a region devoid of synaptobrevin 2, before synaptogenesis. After the onset of synaptogenesis, TI-VAMP/VAMP7 is found predominantly in the somatodendritic domain. In PC12 cells, TI-VAMP/VAMP7 does not colocalize with synaptobrevin 2, chromogranin B, or several markers of endocytic compartments. At the electron microscopic level, TI-VAMP/VAMP7 is mainly associated with tubules and vesicles. Altogether, these results suggest that TI-VAMP/VAMP7 defines a novel membrane compartment in neurite outgrowths and in the somatodendritic domain.
Assuntos
Encéfalo/metabolismo , Proteínas de Membrana/metabolismo , Neurônios/metabolismo , Organelas/metabolismo , Animais , Axônios/metabolismo , Axônios/ultraestrutura , Encéfalo/ultraestrutura , Dendritos/metabolismo , Dendritos/ultraestrutura , Proteínas de Membrana/análise , Terminações Nervosas/metabolismo , Terminações Nervosas/ultraestrutura , Neurônios/ultraestrutura , Especificidade de Órgãos , Organelas/ultraestrutura , Células PC12 , Proteínas R-SNARE , Ratos , Vesículas Sinápticas/ultraestrutura , Toxina Tetânica/farmacologiaRESUMO
Synaptosomal associated protein of 25 kDa (SNAP-25) is a component of the soluble N-ethylmaleimide-sensitive fusion protein (NSF) attachment protein receptor (SNARE) complex which plays a central role in synaptic vesicle exocytosis. We have previously demonstrated that adult rat hippocampal GABAergic synapses, both in culture and in brain, are virtually devoid of SNAP-25 immunoreactivity and are less sensitive to the action of botulinum toxin type A, which cleaves this SNARE protein [Neuron 41 (2004) 599]. In the present study, we extend our findings to the adult mouse hippocampus and we also provide demonstration that hippocampal inhibitory synapses lacking SNAP-25 labeling belong to parvalbumin-, calretinin- and cholecystokinin-positive interneurons. A partial colocalization between SNAP-25 and glutamic acid decarboxylase is instead detectable in developing mouse hippocampus at P0 and, at a lesser extent, at P5. In rat embryonic hippocampal cultures at early developmental stages, SNAP-25 immunoreactivity is detectable in a percentage of GABAergic neurons, which progressively reduces with time in culture. Consistent with the presence of the substrate, botulinum toxin type A is partially effective in inhibiting synaptic vesicle recycling in immature GABAergic neurons. Since SNAP-25, beside its role as a SNARE protein, is involved in additional processes, such as neurite outgrowth and regulation of calcium dynamics, the presence of higher levels of the protein at specific stages of neuronal differentiation may have implications for the construction and for the functional properties of brain circuits.
Assuntos
Hipocampo/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Animais , Biomarcadores , Toxinas Botulínicas Tipo A/farmacologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Células Cultivadas , Técnica Indireta de Fluorescência para Anticorpo , Hipocampo/citologia , Imuno-Histoquímica , Interneurônios/metabolismo , Masculino , Proteínas de Membrana/imunologia , Camundongos , Proteínas do Tecido Nervoso/imunologia , Fármacos Neuromusculares/farmacologia , RNA Mensageiro/biossíntese , RNA Mensageiro/isolamento & purificação , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sinapses/efeitos dos fármacos , Sinapses/fisiologia , Vesículas Sinápticas/efeitos dos fármacos , Proteína 25 Associada a Sinaptossoma , Ácido gama-Aminobutírico/fisiologiaRESUMO
To improve our understanding of the mechanisms which regulate the formation and the functional maturation of synaptic contacts between neurons, we used hippocampal neurons maintained in primary cultures as experimental system. In this model, which offers several advantages for the study of neuronal development and synaptogenesis, we investigated some of the cellular mechanisms underlying the formation of presynaptic and postsynaptic compartments.
Assuntos
Hipocampo/fisiologia , Sinapses/fisiologia , Animais , Células Cultivadas , Hipocampo/citologia , HumanosRESUMO
OBJECTIVES: Oral fields of visually normal and non-dysplastic mucosa (ODFs) may represent the precursors of oral potentially malignant lesions (OPMLs). Aim of the study was to provide new evidence for the concept of the "field carcinogenesis" model by comparing the ODF and OPML genomic aberration profiles obtained by high resolution DNA flow cytometry (hr DNA-FCM) and array-Comparative Genomic Hybridization (a-CGH). A second aim was to investigate if specific CGH aberrations were associated with DNA aneuploidy. METHODS: Nineteen patients with single OPMLs were recruited for the study. In parallel with obtaining samples of OPML tissue from 11 leukoplakias without dysplasia (nd-OPMLs) and 8 with dysplasia (d-OPMLs), we also obtained samples from distant ODFs. DNA aneuploid nuclei detected by hr DNA-FCM were physically separated, based on DNA content, from the DNA diploid components with a DNA-FCM-Sorter. These relatively pure subpopulations of epithelial nuclei were then submitted to DNA extraction and a-CGH for a genome-wide analysis of DNA copy number aberrations (CNAs). RESULTS: The frequencies of DNA aneuploidy (DI ≠ 1) among ODFs and OPMLs were respectively 5.3% and 32%. The DI aneuploid values of ODFs and nd-OPMLs were all near-diploid (DI ≠ 1 and DI ≤ 1.4), while for d-OPMLs were high-aneuploid (DI > 1.4) in 40% of the cases. CNA averages were 1.9 in ODFs and 6.5 in OPMLs. The gain of the chromosomal region 20q13.33-qter was observed in 37% of both ODFs and corresponding OPMLs. Additional common regions included 7p22.2-pter, 11p15.5-pter and 16p13.3-pter where gains were observed. Furthermore, gains of 20q13.31-q13.33 and of 5p13.33-pter and loss of 9p21.3 were detected at high frequency (respectively, at 62.5%, 50% and 50%) only in d-OPMLs. In particular, loss at 9p21.3, gain at 5p13.33-pter and gain of 20q13.31-q13.33 were associated with DNA aneuploidy (p = 0.00004; p = 0.0005; p = 0.01). CONCLUSIONS: ODFs and OPMLs showed common CNAs in specific chromosomal regions suggesting that they may represent early events of the natural history of oral carcinogenesis according to the field effect cancerization and may contribute to the ODF-OPML transition. In addition, loss at 9p21.3 and gains at 5p13.33-pter and 20q13.31-q13.33 may contribute to DNA aneuploidization.
Assuntos
Aberrações Cromossômicas , Genoma Humano/genética , Mucosa Bucal/patologia , Neoplasias Bucais/genética , Neoplasias Bucais/patologia , Lesões Pré-Cancerosas/genética , Lesões Pré-Cancerosas/patologia , Adulto , Idoso , Aneuploidia , Cromossomos Humanos/genética , Hibridização Genômica Comparativa , Variações do Número de Cópias de DNA/genética , DNA de Neoplasias/genética , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Neuroblastoma is an extracranial solid tumor which occurs in infants and young children and accounts for 8% of pediatric cancers. It origins from neural crest cells of the sympathetic nervous system. Disease-free survival ranges from 95% for localized tumors to 30% for metastatic disease in children over 1 year of age and patients' outcome depends on dissemination and tissue histology. Despite the most recent therapies, the overall survival for high risk patients is still low and the outcome is invariably fatal. Improvement of neuroblastoma treatment is one of the highest priorities in pediatric oncology and a major challenge to clinicians and researchers. Understanding the biology and genetics of pediatric malignancies will be the key to identify molecular targets for innovative treatments as well as to individual management of disease. The success of human genome project and recent advances in technology have provided new tools to investigate cancer cells and to discover new tumor-associated genes. High-throughput efforts include array-based comparative genomic hybridization, single-nucleotide polymorphism arrays and expression microarrays. Here we present an overview on the most recent advances in wide-genome analysis of neuroblastoma. We also focus on the potential clinical application of genome and transcriptome information to the diagnosis, prognosis and neuroblastoma therapy.