RESUMO
Neuroblastoma, a type of cancer that is common in children, is composed of two genetically clonal but epigenetically distinct cell types: mesenchymal (MES) and adrenergic (ADRN) types, controlled by super-enhancer-associated lineage-specific transcription factor networks. Mesenchymal-type cells are more migratory, resistant to chemotherapy, and prevalent in relapse tumors. Importantly, both cell types spontaneously transdifferentiate into one another, and this interconversion can be induced by genetic manipulations. However, the mechanisms of their spontaneous transdifferentiation and extracellular factors inducing this phenomenon have not yet been elucidated. Using a unique approach involving gene set enrichment analysis, we selected six ADRN and 10 MES candidate factors, possibly inducing ADRN and MES phenotypes, respectively. Treatment with a combination of 10 MES factors clearly induced the MES gene expression profile in ADRN-type SH-SY5Y neuroblastoma cells. Considering the effects on gene expression profile, migration ability, and chemoresistance, a combination of tumor necrosis factor alpha (TNF-α) and epidermal growth factor (EGF) was sufficient to synergistically induce the ADRN-to-MES transdifferentiation in SH-SY5Y cells. In addition, human neuroblastoma cohort analysis revealed that the expression of TNF and EGF receptors was strongly associated with MES gene expression signatures, supporting their important roles in transdifferentiation in vivo. Collectively, we propose a mechanism of neuroblastoma transdifferentiation induced by extracellular growth factors, which can be controlled in clinical situations, providing a new therapeutic possibility.
Assuntos
Neurônios Adrenérgicos/patologia , Transdiferenciação Celular/fisiologia , Fator de Crescimento Epidérmico/metabolismo , Neuroblastoma/patologia , Fator de Necrose Tumoral alfa/metabolismo , Linhagem Celular Tumoral , HumanosAssuntos
Neurônios Adrenérgicos/patologia , Encéfalo/fisiologia , Neurônios Colinérgicos/patologia , Neoplasias/patologia , Neurogênese/fisiologia , Neurônios Adrenérgicos/fisiologia , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/secundário , Mama/inervação , Mama/patologia , Carcinogênese/patologia , Comunicação Celular/fisiologia , Neurônios Colinérgicos/fisiologia , Feminino , Humanos , Masculino , Próstata/inervação , Próstata/patologia , Microambiente Tumoral/fisiologiaRESUMO
The solid tumour microenvironment includes nerve fibres that arise from the peripheral nervous system1,2. Recent work indicates that newly formed adrenergic nerve fibres promote tumour growth, but the origin of these nerves and the mechanism of their inception are unknown1,3. Here, by comparing the transcriptomes of cancer-associated trigeminal sensory neurons with those of endogenous neurons in mouse models of oral cancer, we identified an adrenergic differentiation signature. We show that loss of TP53 leads to adrenergic transdifferentiation of tumour-associated sensory nerves through loss of the microRNA miR-34a. Tumour growth was inhibited by sensory denervation or pharmacological blockade of adrenergic receptors, but not by chemical sympathectomy of pre-existing adrenergic nerves. A retrospective analysis of samples from oral cancer revealed that p53 status was associated with nerve density, which was in turn associated with poor clinical outcomes. This crosstalk between cancer cells and neurons represents mechanism by which tumour-associated neurons are reprogrammed towards an adrenergic phenotype that can stimulate tumour progression, and is a potential target for anticancer therapy.
Assuntos
Neurônios Adrenérgicos/patologia , Transdiferenciação Celular , Reprogramação Celular , Neoplasias Bucais/patologia , Células Receptoras Sensoriais/patologia , Proteína Supressora de Tumor p53/deficiência , Antagonistas Adrenérgicos/farmacologia , Antagonistas Adrenérgicos/uso terapêutico , Animais , Divisão Celular , Modelos Animais de Doenças , Progressão da Doença , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , MicroRNAs/genética , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/genética , Neoplasias Bucais/metabolismo , Fibras Nervosas/patologia , Neuritos/patologia , Receptores Adrenérgicos/metabolismo , Estudos Retrospectivos , Microambiente Tumoral , Proteína Supressora de Tumor p53/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Aberrant Tau inclusions in the locus coeruleus (LC) are the earliest detectable Alzheimer's disease-like (AD-like) neuropathology in the human brain. However, why LC neurons are selectively vulnerable to developing early Tau pathology and degenerating later in disease and whether the LC might seed the stereotypical spread of Tau pathology to the rest of the brain remain unclear. Here, we show that 3,4-dihydroxyphenylglycolaldehyde, which is produced exclusively in noradrenergic neurons by monoamine oxidase A metabolism of norepinephrine, activated asparagine endopeptidase that cleaved Tau at residue N368 into aggregation- and propagation-prone forms, thus leading to LC degeneration and the spread of Tau pathology. Activation of asparagine endopeptidase-cleaved Tau aggregation in vitro and in intact cells was triggered by 3,4-dihydroxyphenylglycolaldehyde, resulting in LC neurotoxicity and propagation of pathology to the forebrain. Thus, our findings reveal that norepinephrine metabolism and Tau cleavage represent the specific molecular mechanism underlying the selective vulnerability of LC neurons in AD.
Assuntos
Neurônios Adrenérgicos/metabolismo , Aldeídos/metabolismo , Doença de Alzheimer/metabolismo , Locus Cerúleo/metabolismo , Agregação Patológica de Proteínas/metabolismo , Proteínas tau/metabolismo , Neurônios Adrenérgicos/patologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Animais , Catecóis , Linhagem Celular Tumoral , Feminino , Células HEK293 , Humanos , Locus Cerúleo/patologia , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Norepinefrina/genética , Norepinefrina/metabolismo , Agregação Patológica de Proteínas/genética , Agregação Patológica de Proteínas/patologia , Proteínas tau/genéticaRESUMO
Autonomic nerve fibres in the tumour microenvironment regulate cancer initiation and dissemination, but how nerves emerge in tumours is currently unknown. Here we show that neural progenitors from the central nervous system that express doublecortin (DCX+) infiltrate prostate tumours and metastases, in which they initiate neurogenesis. In mouse models of prostate cancer, oscillations of DCX+ neural progenitors in the subventricular zone-a neurogenic area of the central nervous system-are associated with disruption of the blood-brain barrier, and with the egress of DCX+ cells into the circulation. These cells then infiltrate and reside in the tumour, and can generate new adrenergic neurons. Selective genetic depletion of DCX+ cells inhibits the early phases of tumour development in our mouse models of prostate cancer, whereas transplantation of DCX+ neural progenitors promotes tumour growth and metastasis. In humans, the density of DCX+ neural progenitors is strongly associated with the aggressiveness and recurrence of prostate adenocarcinoma. These results reveal a unique crosstalk between the central nervous system and prostate tumours, and indicate neural targets for the treatment of cancer.
Assuntos
Sistema Nervoso Central/patologia , Células-Tronco Neurais/patologia , Neurogênese , Neoplasias da Próstata/patologia , Adenocarcinoma/patologia , Neurônios Adrenérgicos/patologia , Animais , Carcinogênese , Diferenciação Celular , Modelos Animais de Doenças , Proteínas do Domínio Duplacortina , Proteína Duplacortina , Genes myc , Humanos , Ventrículos Laterais/patologia , Masculino , Camundongos , Proteínas Associadas aos Microtúbulos/metabolismo , Células-Tronco Neurais/metabolismo , Neuropeptídeos/metabolismo , Bulbo Olfatório/patologia , PrognósticoRESUMO
Transition between differentiation states in development occurs swift but the mechanisms leading to epigenetic and transcriptional reprogramming are poorly understood. The pediatric cancer neuroblastoma includes adrenergic (ADRN) and mesenchymal (MES) tumor cell types, which differ in phenotype, super-enhancers (SEs) and core regulatory circuitries. These cell types can spontaneously interconvert, but the mechanism remains largely unknown. Here, we unravel how a NOTCH3 intracellular domain reprogrammed the ADRN transcriptional landscape towards a MES state. A transcriptional feed-forward circuitry of NOTCH-family transcription factors amplifies the NOTCH signaling levels, explaining the swift transition between two semi-stable cellular states. This transition induces genome-wide remodeling of the H3K27ac landscape and a switch from ADRN SEs to MES SEs. Once established, the NOTCH feed-forward loop maintains the induced MES state. In vivo reprogramming of ADRN cells shows that MES and ADRN cells are equally oncogenic. Our results elucidate a swift transdifferentiation between two semi-stable epigenetic cellular states.
Assuntos
Neurônios Adrenérgicos/patologia , Reprogramação Celular/genética , Células-Tronco Mesenquimais/patologia , Neuroblastoma/patologia , Receptor Notch3/fisiologia , Neurônios Adrenérgicos/metabolismo , Linhagem Celular Tumoral , Epigênese Genética , Retroalimentação Fisiológica , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Células-Tronco Mesenquimais/metabolismo , Neuroblastoma/metabolismo , Receptor Notch3/genética , Receptor Notch3/metabolismoRESUMO
Lewy body diseases involve neurogenic orthostatic hypotension (nOH), cardiac noradrenergic deficiency, and deposition of the protein AS (alpha-synuclein) in sympathetic ganglion tissue. Mechanisms linking these abnormalities are poorly understood. One link may be AS deposition within sympathetic neurons. We validated methodology to quantify AS colocalization with TH (tyrosine hydroxylase), a marker of sympathetic noradrenergic innervation, and assessed associations of AS/TH colocalization with myocardial norepinephrine content and cardiac sympathetic neuroimaging data in nOH. Postmortem sympathetic ganglionic AS/TH colocalization indices and myocardial norepinephrine contents were measured in 4 Lewy body and 3 rare non-Lewy body nOH patients. Sixteen Lewy body and 11 non-Lewy body nOH patients underwent in vivo skin biopsies and thoracic 18F-dopamine positron emission tomographic scanning, with cutaneous colocalization indices expressed versus cardiac 18F-dopamine-derived radioactivity. Ganglionic AS/TH colocalization indices were higher and myocardial norepinephrine lower in Lewy body than non-Lewy body nOH ( P=0.0020, P=0.014). The Lewy body nOH group had higher AS/TH colocalization indices in skin biopsies and lower myocardial 18F-dopamine-derived radioactivity than did the non-Lewy body nOH group ( P<0.0001 each). All Lewy body nOH patients had colocalization indices >1.5 in skin biopsies and 18F-dopamine-derived radioactivity <6000 nCi-kg/cc-mCi, a combination not seen in non-Lewy body nOH patients ( P<0.0001). In Lewy body nOH, AS deposition in sympathetic noradrenergic nerves is related to postmortem neurochemical and in vivo neuroimaging evidence of myocardial noradrenergic deficiency. These associations raise the possibility that intraneuronal AS deposition plays a pathophysiological role in the myocardial sympathetic neurodegeneration attending Lewy body nOH.
Assuntos
Neurônios Adrenérgicos/metabolismo , Hipotensão Ortostática/metabolismo , Corpos de Lewy/metabolismo , Miocárdio/metabolismo , alfa-Sinucleína/metabolismo , Neurônios Adrenérgicos/patologia , Idoso , Idoso de 80 Anos ou mais , Biópsia , Feminino , Humanos , Hipotensão Ortostática/diagnóstico , Hipotensão Ortostática/fisiopatologia , Corpos de Lewy/patologia , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Tomografia por Emissão de Pósitrons , Pele/metabolismo , Pele/patologiaRESUMO
Regulating immunity is a leading target for cancer therapy. Here, we show that the anti-tumor immune response can be modulated by the brain's reward system, a key circuitry in emotional processes. Activation of the reward system in tumor-bearing mice (Lewis lung carcinoma (LLC) and B16 melanoma) using chemogenetics (DREADDs), resulted in reduced tumor weight. This effect was mediated via the sympathetic nervous system (SNS), manifested by an attenuated noradrenergic input to a major immunological site, the bone marrow. Myeloid derived suppressor cells (MDSCs), which develop in the bone marrow, became less immunosuppressive following reward system activation. By depleting or adoptively transferring the MDSCs, we demonstrated that these cells are both necessary and sufficient to mediate reward system effects on tumor growth. Given the central role of the reward system in positive emotions, these findings introduce a physiological mechanism whereby the patient's psychological state can impact anti-tumor immunity and cancer progression.
Assuntos
Carcinoma Pulmonar de Lewis/tratamento farmacológico , Clozapina/análogos & derivados , Fatores Imunológicos/farmacologia , Melanoma Experimental/tratamento farmacológico , Células Supressoras Mieloides/efeitos dos fármacos , Recompensa , Área Tegmentar Ventral/efeitos dos fármacos , Neurônios Adrenérgicos/efeitos dos fármacos , Neurônios Adrenérgicos/imunologia , Neurônios Adrenérgicos/patologia , Animais , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/imunologia , Células da Medula Óssea/patologia , Carcinoma Pulmonar de Lewis/imunologia , Carcinoma Pulmonar de Lewis/patologia , Clozapina/farmacologia , Dopamina/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/imunologia , Neurônios Dopaminérgicos/patologia , Imunidade Inata/efeitos dos fármacos , Injeções Intraventriculares , Masculino , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células Supressoras Mieloides/imunologia , Células Supressoras Mieloides/patologia , Norepinefrina/metabolismo , Técnicas Estereotáxicas , Sistema Nervoso Simpático/efeitos dos fármacos , Sistema Nervoso Simpático/imunologia , Sistema Nervoso Simpático/patologia , Carga Tumoral/efeitos dos fármacos , Área Tegmentar Ventral/imunologia , Área Tegmentar Ventral/patologiaRESUMO
OBJECTIVE: To evaluate the impact of prolapse meshes on vaginal smooth muscle structure (VaSM) and function, and to evaluate these outcomes in the context of the mechanical and textile properties of the mesh. DESIGN: Three months following the implantation of three polypropylene prolapse meshes with distinct textile and mechanical properties, mesh tissue explants were evaluated for smooth muscle contraction, innervation, receptor function, and innervation density. SETTING: Magee-Womens Research Institute at the University of Pittsburgh. POPULATION: Thirty-four parous rhesus macaques of similar age, parity, and pelvic organ prolapse quantification (POP-Q) scores. METHODS: Macaques were implanted with mesh via sacrocolpopexy. The impact of Gynemesh(™) PS (Ethicon; n = 7), Restorelle(®) (Coloplast; n = 7), UltraPro(™) parallel and UltraPro(™) perpendicular (Ethicon; n = 6 and 7, respectively) were compared with sham-operated controls (n = 7). Outcomes were analysed by Kruskal-Wallis ANOVA, Mann-Whitney U-tests and multiple regression analysis (P < 0.05). MEAN OUTCOME MEASURES: Vaginal tissue explants were evaluated for the maximum contractile force generated following muscle, nerve, and receptor stimulation, and for peripheral nerve density. RESULTS: Muscle myofibre, nerve, and receptor-mediated contractions were negatively affected by mesh only in the grafted region (P < 0.001, P = 0.002, and P = 0.008, respectively), whereas cholinergic and adrenergic nerve densities were affected in the grafted (P = 0.090 and P = 0.008, respectively) and non-grafted (P = 0.009 and P = 0.005, respectively) regions. The impact varied by mesh property, as mesh stiffness was a significant predictor of the negative affect on muscle function and nerve density (P < 0.001 and P = 0.013, respectively), whereas mesh and weight was a predictor of receptor function (P < 0.001). CONCLUSIONS: Mesh has an overall negative impact on VaSM, and the effects are a function of mesh properties, most notably, mesh stiffness. TWEETABLE ABSTRACT: Prolapse mesh affects vaginal smooth muscle.
Assuntos
Músculo Liso/patologia , Prolapso de Órgão Pélvico/cirurgia , Polipropilenos/efeitos adversos , Telas Cirúrgicas/efeitos adversos , Vagina/patologia , Neurônios Adrenérgicos/patologia , Neurônios Adrenérgicos/fisiologia , Animais , Fenômenos Biomecânicos , Biópsia/métodos , Neurônios Colinérgicos/patologia , Neurônios Colinérgicos/fisiologia , Desenho de Equipamento , Feminino , Macaca mulatta , Agonistas Muscarínicos/farmacologia , Contração Muscular/fisiologia , Fibras Musculares Esqueléticas/patologia , Fibras Musculares Esqueléticas/fisiologia , Músculo Liso/inervação , Músculo Liso/fisiopatologia , Prolapso de Órgão Pélvico/patologia , Prolapso de Órgão Pélvico/fisiopatologia , Nervos Periféricos/patologia , Nervos Periféricos/fisiopatologia , Polipropilenos/administração & dosagem , Receptores Muscarínicos/efeitos dos fármacos , Receptores Muscarínicos/fisiologia , Vagina/inervação , Vagina/fisiopatologiaRESUMO
Neuroblastoma is an embryonal pediatric tumor that originates from the developing sympathetic nervous system and shows a broad range of clinical behavior, ranging from fatal progression to differentiation into benign ganglioneuroma. In experimental neuroblastoma systems, retinoic acid (RA) effectively induces neuronal differentiation, and RA treatment has been therefore integrated in current therapies. However, the molecular mechanisms underlying differentiation are still poorly understood. We here investigated the role of transcription factor activating protein 2 beta (TFAP2B), a key factor in sympathetic nervous system development, in neuroblastoma pathogenesis and differentiation. Microarray analyses of primary neuroblastomas (n = 649) demonstrated that low TFAP2B expression was significantly associated with unfavorable prognostic markers as well as adverse patient outcome. We also found that low TFAP2B expression was strongly associated with CpG methylation of the TFAP2B locus in primary neuroblastomas (n = 105) and demethylation with 5-aza-2'-deoxycytidine resulted in induction of TFAP2B expression in vitro, suggesting that TFAP2B is silenced by genomic methylation. Tetracycline inducible re-expression of TFAP2B in IMR-32 and SH-EP neuroblastoma cells significantly impaired proliferation and cell cycle progression. In IMR-32 cells, TFAP2B induced neuronal differentiation, which was accompanied by up-regulation of the catecholamine biosynthesizing enzyme genes DBH and TH, and down-regulation of MYCN and REST, a master repressor of neuronal genes. By contrast, knockdown of TFAP2B by lentiviral transduction of shRNAs abrogated RA-induced neuronal differentiation of SH-SY5Y and SK-N-BE(2)c neuroblastoma cells almost completely. Taken together, our results suggest that TFAP2B is playing a vital role in retaining RA responsiveness and mediating noradrenergic neuronal differentiation in neuroblastoma.
Assuntos
Neurônios Adrenérgicos/patologia , Neuroblastoma/patologia , Fator de Transcrição AP-2/metabolismo , Adolescente , Neurônios Adrenérgicos/metabolismo , Adulto , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Ciclo Celular , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Criança , Pré-Escolar , Ilhas de CpG/genética , Metilação de DNA/efeitos dos fármacos , Decitabina , Dopamina beta-Hidroxilase/metabolismo , Regulação para Baixo , Técnicas de Silenciamento de Genes , Humanos , Lactente , Recém-Nascido , Proteína Proto-Oncogênica N-Myc , Neuroblastoma/genética , Neuroblastoma/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Oncogênicas/metabolismo , Prognóstico , Regiões Promotoras Genéticas , RNA Interferente Pequeno/metabolismo , Proteínas Repressoras/metabolismo , Fator de Transcrição AP-2/genética , Tretinoína/farmacologia , Tirosina 3-Mono-Oxigenase/metabolismo , Regulação para Cima , Adulto JovemRESUMO
Adrenergic and cholinergic innervation of the pharyngeal tonsil was studied in 50 children aged 4 to 14 years with chronic adenoiditis. that was removed during the operation from. The children were divided into 3 groups. The 1st group included children with decreased tone of the autonomic nervous system (ANS) and autonomic hyperreactivity, the 2nd group children with increased ANS tone and low autonomic reactivity, the 3rd group children with optimal autonomic tone and normal reactivity. The state of the nervous structures in the region of adenoid overgrowths was studied by histochemical methods, demonstrating adren- and cholinergic nerve fibers in the same section (incubation in glyoxylic acid and KarnovskyRoots method). Adrenergic nerve fibers with many varicosities were found mainly in perivasal plexuses, from which the branches passed subepithelially between the nodules, and the terminals ofthin fibers penetrated the lymphoid nodules. The assessment of the functional activity of adrenergic nerve fibers demonstrated that in the 1st group the average luminescence intensity in varicose extensions and intervaricose areas was equal to 22.7±2.5 and 37,2±3.5 conventional units (c.u.), respectively, in the 2nd group it was equal to 57.3±1,4 and 15.5±4.3 c.u., while in the 3rd group to 34,3±2,2 and 30.1±3.8 c.u. It was found that cholinergic nerve fibers were located similarly to adrenergic fibers, but appeared thicker and had larger varicosities. The activity of cholinergic nerve structures could be evaluated by the staining intensity (from light yellow to dark brown) and by the number of varicose extensions in a certain fiber. Similar to adrenergic fibers, cholinergic nerve fibers often passed from perivascular plexuses and innervated the lymphoid tissue.
Assuntos
Tonsila Faríngea , Neurônios Adrenérgicos/patologia , Neurônios Colinérgicos/patologia , Linfadenite/patologia , Tonsila Faríngea/inervação , Tonsila Faríngea/patologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , MasculinoAssuntos
Neurônios Adrenérgicos/patologia , Transtorno do Deficit de Atenção com Hiperatividade/patologia , Classe Ib de Fosfatidilinositol 3-Quinase/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Locus Cerúleo/patologia , Transdução de Sinais , AnimaisRESUMO
Although PI3Kγ has been extensively investigated in inflammatory and cardiovascular diseases, the exploration of its functions in the brain is just at dawning. It is known that PI3Kγ is present in neurons and that the lack of PI3Kγ in mice leads to impaired synaptic plasticity, suggestive of a role in behavioral flexibility. Several neuropsychiatric disorders, such as attention-deficit/hyperactivity disorder (ADHD), involve an impairment of behavioral flexibility. Here, we found a previously unreported expression of PI3Kγ throughout the noradrenergic neurons of the locus coeruleus (LC) in the brainstem, serving as a mechanism that regulates its activity of control on attention, locomotion and sociality. In particular, we show an unprecedented phenotype of PI3Kγ KO mice resembling ADHD symptoms. PI3Kγ KO mice exhibit deficits in the attentive and mnemonic domains, typical hyperactivity, as well as social dysfunctions. Moreover, we demonstrate that the ADHD phenotype depends on a dysregulation of CREB signaling exerted by a kinase-independent PI3Kγ-PDE4D interaction in the noradrenergic neurons of the locus coeruleus, thus uncovering new tools for mechanistic and therapeutic research in ADHD.
Assuntos
Neurônios Adrenérgicos/patologia , Transtorno do Deficit de Atenção com Hiperatividade/patologia , Classe Ib de Fosfatidilinositol 3-Quinase/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Locus Cerúleo/patologia , Transdução de Sinais , Animais , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Modelos Animais de Doenças , Locus Cerúleo/fisiopatologia , Camundongos , Camundongos Knockout , Ligação ProteicaRESUMO
Neuroblastoma (NB), although rare, accounts for 15% of all paediatric cancer mortality. Unusual among cancers, NBs lack a consistent set of gene mutations and, excluding large-scale chromosomal rearrangements, the genome seems to be largely intact. Indeed, many interesting features of NB suggest that it has little in common with adult solid tumours but instead has characteristics of a developmental disorder. NB arises overwhelmingly in infants under 2 years of age during a specific window of development and, histologically, NB bears striking similarity to undifferentiated neuroblasts of the sympathetic nervous system, its likely cells of origin. Hence, NB could be considered a disease of development arising when neuroblasts of the sympathetic nervous system fail to undergo proper differentiation, but instead are maintained precociously as progenitors with the potential for acquiring further mutations eventually resulting in tumour formation. To explore this possibility, we require a robust and flexible developmental model to investigate the differentiation of NB's presumptive cell of origin. Here, we use Xenopus frog embryos to characterise the differentiation of anteroventral noradrenergic (AVNA) cells, cells derived from the neural crest. We find that these cells share many characteristics with their mammalian developmental counterparts, and also with NB cells. We find that the transcriptional regulator Ascl1 is expressed transiently in normal AVNA cell differentiation but its expression is aberrantly maintained in NB cells, where it is largely phosphorylated on multiple sites. We show that Ascl1's ability to induce differentiation of AVNA cells is inhibited by its multi-site phosphorylation at serine-proline motifs, whereas overexpression of cyclin-dependent kinases (CDKs) and MYCN inhibit wild-type Ascl1-driven AVNA differentiation, but not differentiation driven by a phospho-mutant form of Ascl1. This suggests that the maintenance of ASCL1 in its multiply phosphorylated state might prevent terminal differentiation in NB, which could offer new approaches for differentiation therapy in NB.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Diferenciação Celular , Proteínas do Tecido Nervoso/metabolismo , Neuroblastoma/embriologia , Neuroblastoma/metabolismo , Neurônios/patologia , Proteínas de Xenopus/metabolismo , Xenopus laevis/embriologia , Xenopus laevis/metabolismo , Neurônios Adrenérgicos/efeitos dos fármacos , Neurônios Adrenérgicos/metabolismo , Neurônios Adrenérgicos/patologia , Animais , Biomarcadores/metabolismo , Diferenciação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p27 , Quinases Ciclina-Dependentes/metabolismo , Modelos Animais de Doenças , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Técnicas de Silenciamento de Genes , Morfolinos/farmacologia , Crista Neural/citologia , Neuroblastoma/patologia , Neurogênese/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-myc/metabolismoRESUMO
BACKGROUND: The principal components of the enteric nervous system (ENS) are two neuronal networks, the myenteric and submucosal plexus (SMP), which are primarily involved in the regulation of gastrointestinal (GI) motility and secretion, respectively. These two plexus are made up of intrinsic neurons receiving input from the extrinsic sympathetic and parasympathetic innervation of the gut. Both the intrinsic and extrinsic innervations of the gut are affected by Lewy pathology in Parkinson's disease (PD). A recent autopsy survey indicated that there was no global or dopaminergic loss in the myenteric plexus in PD but the SMP was not examined. OBJECTIVE: The aim of the present work was to compare the relative abundance of dopaminergic and noradrenergic neurons in colonic biopsies between PD patients and control individuals. METHODS: Colonic biopsies were taken during the course of a colonoscopy in 35 PD patients and 10 control subjects. Density of dopaminergic neurons and expression of the dopaminergic and noradrenergic markers were analyzed by tyrosine hydroxylase (TH) immunofluorescence and Western blot using anti-dopamine transporter (DAT) and anti-dopamine beta-hydroxylase (DBH), respectively. RESULTS: No significant differences were observed in the density of dopaminergic neurons and in the expression levels of dopaminergic and noradrenergic markers in colonic biopsies from PD patients as compared to controls. CONCLUSION: Our results indicate that there is no evidence of dopaminergic and noradrenergic neuronal loss in the SMP in PD, thereby suggesting that neuropathology in submucosal neurons is unlikely to be a causative factor for GI dysfunction in PD.
Assuntos
Neurônios Adrenérgicos/patologia , Neurônios Dopaminérgicos/patologia , Doença de Parkinson/patologia , Plexo Submucoso/patologia , Neurônios Adrenérgicos/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Contagem de Células , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Dopamina beta-Hidroxilase/metabolismo , Neurônios Dopaminérgicos/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Neurofilamentos/metabolismo , Fosfoproteínas/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
INTRODUCTION: Fibromyalgia (FM) is a chronic syndrome characterized by widespread pain often accompanied by other symptoms suggestive of neuropathic pain. We evaluated patients for small fiber neuropathy (SFN) who were referred for fibromyalgia (FM). METHODS: We studied 20 consecutive subjects with primary FM. Patients underwent neurological examination, nerve conduction studies, and skin biopsies from distal leg and thigh. RESULTS: Electrodiagnostic studies were normal in all patients. SFN was diagnosed in 6 patients by reduced epidermal nerve fiber density. These patients also showed abnormalities of both adrenergic and cholinergic fibers. CONCLUSIONS: A subset of FM subjects have SFN, which may contribute to their sensory and autonomic symptoms. Skin biopsy should be considered in the diagnostic work-up of FM.