Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 86
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
EMBO J ; 39(12): e103499, 2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-32368833

RESUMO

Primary cilia are antenna-like organelles on the surface of most mammalian cells that receive sonic hedgehog (Shh) signaling in embryogenesis and carcinogenesis. Cellular cholesterol functions as a direct activator of a seven-transmembrane oncoprotein called Smoothened (Smo) and thereby induces Smo accumulation on the ciliary membrane where it transduces the Shh signal. However, how cholesterol is supplied to the ciliary membrane remains unclear. Here, we report that peroxisomes are essential for the transport of cholesterol into the ciliary membrane. Zellweger syndrome (ZS) is a peroxisome-deficient hereditary disorder with several ciliopathy-related features and cells from these patients showed a reduced cholesterol level in the ciliary membrane. Reverse genetics approaches revealed that the GTP exchange factor Rabin8, the Rab GTPase Rab10, and the microtubule minus-end-directed kinesin KIFC3 form a peroxisome-associated complex to control the movement of peroxisomes along microtubules, enabling communication between peroxisomes and ciliary pocket membranes. Our findings suggest that insufficient ciliary cholesterol levels may underlie ciliopathies.


Assuntos
Colesterol/metabolismo , Cílios/metabolismo , Síndrome de Zellweger/metabolismo , Células Cultivadas , Colesterol/genética , Cílios/genética , Cílios/patologia , Quinases do Centro Germinativo/genética , Quinases do Centro Germinativo/metabolismo , Humanos , Cinesinas/genética , Cinesinas/metabolismo , Microtúbulos/genética , Microtúbulos/metabolismo , Microtúbulos/patologia , Receptor Smoothened/genética , Receptor Smoothened/metabolismo , Síndrome de Zellweger/genética , Síndrome de Zellweger/patologia , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo
2.
Biochem Biophys Res Commun ; 610: 85-91, 2022 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-35453040

RESUMO

The primary cilium is a specialized microtubule-based sensory organelle that extends from the cell body of nearly all cell types. Neuronal primary cilia, which have their own unique signaling repertoire, are crucial for neuronal integrity and the maintenance of neuronal connectivity throughout adulthood. Dysfunction of cilia structure and ciliary signaling is associated with a variety of genetic syndromes, termed ciliopathies. One of the characteristic features of human ciliopathies is impairment of memory and cognition, which is also observed in Alzheimer's disease (AD). Amyloid ß peptide (Aß) is produced through the proteolytic processing of amyloid precursor protein (APP), and Aß accumulation in the brain is proposed to be an early toxic event in the pathogenesis of AD. To evaluate the effect of increased Aß level on primary cilia, we assessed ciliary dynamics in hippocampal neurons in an APP knock-in AD model (AppNL-G-F mice) compared to that in wild-type mice. Neuronal cilia length in the CA1, CA3, and dentate gyrus (DG) of wild-type mice increased significantly with age. In AppNL-G-F mice, such elongation was detected in the DG but not in the CA1 and CA3, where more Aß accumulation was observed. We further demonstrated that Aß1-42 treatment decreased cilia length both in hTERT-RPE1 cells and dissociated rat hippocampal neurons. There is growing evidence that reduced cilia length is associated with perturbations of synaptic connectivity and dendrite complexity. Thus, our observations raise the important possibility that structural alterations in neuronal cilia might have a role in AD development.


Assuntos
Doença de Alzheimer , Ciliopatias , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Ratos
3.
Eur J Neurol ; 28(4): 1113-1122, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33305428

RESUMO

OBJECTIVE: This study aimed to examine echolalia and its related symptoms and brain lesions in primary progressive aphasia (PPA). METHODS: Forty-five patients with PPA were included: 19 nonfluent/agrammatic variant PPA (nfvPPA), 5 semantic variant PPA, 7 logopenic variant PPA, and 14 unclassified PPA patients. We detected echolalia in unstructured conversations. An evaluation of language function and the presence of parkinsonism, grasp reflex, imitation behaviour, and disinhibition were assessed. We also measured regional cerebral blood flow (rCBF) using single-photon emission computed tomography. RESULTS: Echolalia was observed in 12 nfvPPA and 2 unclassified PPA patients. All patients showed mitigated echolalia. We compared nfvPPA patients with echolalia (echolalia group) to those without echolalia (non-echolalia group). The median age of the echolalia group was significantly lower than that of the non-echolalia group, and the echolalia group showed a significantly worse auditory comprehension performance than the non-echolalia group. In contrast, the performance of repetition tasks was not different between the two groups. The prevalence of imitation behaviour in the echolalia group was significantly higher than that in the non-echolalia group. The rCBFs in the bilateral pre-supplementary motor area and bilateral middle cingulate cortex in the echolalia group were significantly lower than those in the non-echolalia group. CONCLUSIONS: These findings suggest that echolalia is characteristic of nfvPPA patients with impaired comprehension. Reduced inhibition of the medial frontal cortex with release activity of the anterior perisylvian area account for the emergence of echolalia.


Assuntos
Afasia Primária Progressiva , Afasia , Afasia Primária Progressiva não Fluente , Afasia Primária Progressiva/diagnóstico por imagem , Afasia Primária Progressiva/epidemiologia , Ecolalia , Humanos , Idioma
4.
Gastric Cancer ; 24(1): 190-196, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32700159

RESUMO

BACKGROUND: This is a phase 2 study aimed at evaluating the efficacy and safety of TAS-114, a novel deoxyuridine triphosphatase inhibitor, combined with S-1 in patients with advanced gastric cancer (AGC). METHODS: Eligible patients had AGC with measurable lesions, according to the Response Evaluation Criteria in Solid Tumors (RECIST, v1.1), with two or more previous chemotherapy regimens including fluoropyrimidines, platinum agents, and taxanes or irinotecan. The primary endpoint was objective response rate (ORR) according to the RECIST, v1.1. Twenty-nine patients were required according to Simon's optimal two-stage design, with one-sided a = 5% and power = 80%. Threshold and expected ORRs were 5% and 25%. Patients received TAS-114 (400 mg/body, twice a day) and S-1 (30 mg/m2, twice a day) for 14 days, followed by 7 days of rest in one 3-week cycle. Protein expression levels of dUTPase and BRCA1 in tumor samples were determined by immunohistochemistry. RESULTS: Accrual was terminated in June 2018 because meeting the predefined efficacy criteria was considered difficult. ORR and disease control rate were 5.0% [95% confidence interval (CI), 0.1-24.9%] and 70.0% (95% CI, 45.7-88.1%), respectively, for all 20 patients enrolled. Median progression-free survival (PFS) and overall survival were 2.4 months (95% CI, 1.2-3.3 months) and 7.1 months (95% CI, 5.2-9.4 months), respectively. Median PFS in the groups with high and low dUTPase protein expression in the cytoplasm was 2.8 months (95% CI, 1.4-3.9) and 1.6 months (95% CI, 0.6-2.4), respectively [hazard ratio, 0.40 (95% CI, 0.16-1.04), log-rank test two-sided p = 0.047]. Grade 3 or higher treatment-related adverse events included anemia (20%), leucopenia (15%), neutropenia (10%), rash (10%), thrombocytopenia (5%), and lymphopenia (5%) CONCLUSIONS: TAS-114 with S-1 showed only modest antitumor activity with acceptable safety profiles for patients heavily pretreated with AGC.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Ácido Oxônico/administração & dosagem , Pirimidinas/administração & dosagem , Neoplasias Gástricas/tratamento farmacológico , Sulfonamidas/administração & dosagem , Tegafur/administração & dosagem , Adulto , Idoso , Combinação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intervalo Livre de Progressão , Modelos de Riscos Proporcionais , Pirofosfatases/metabolismo , Critérios de Avaliação de Resposta em Tumores Sólidos , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Ubiquitina-Proteína Ligases/metabolismo
5.
J Phys Ther Sci ; 33(3): 307-311, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33814721

RESUMO

[Purpose] We report our experience with a patient with a central spinal cord injury who showed improved finger and upper limb functions after long-term treatment with a combination of rehabilitation and botulinum toxin type A. [Participants and Methods] The patient had spasms and pain that gradually became more profound and was given botulinum toxin type A at 1 year 3 months after sustaining a spinal cord injury. We administered 14 botulinum toxin type A injections periodically for 7 years 4 months after the injury. We administered the injections at an average interval of 5.6 months. Splints that allowed extension and improved finger muscle tone and contracture were made for the patient. [Results] The patient experienced gradual alleviation of the spasms in the proximal upper limb muscles and improved range of motion after receiving five doses of botulinum toxin type A. The spasms and range of motion in the fingers gradually improved around 4 years after the injury through splint therapy and a combination of botulinum toxin type A administration and rehabilitation. [Conclusion] The combination of botulinum toxin type A, splint, and rehabilitation therapies can lead to positive improvements in finger spasticity and range of motion and is recommended for hypertonia cases with severe contractures.

6.
J Neurosci ; 39(50): 9967-9988, 2019 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-31685650

RESUMO

New neurons, referred to as neuroblasts, are continuously generated in the ventricular-subventricular zone of the brain throughout an animal's life. These neuroblasts are characterized by their unique potential for proliferation, formation of chain-like cell aggregates, and long-distance and high-speed migration through the rostral migratory stream (RMS) toward the olfactory bulb (OB), where they decelerate and differentiate into mature interneurons. The dynamic changes of ultrastructural features in postnatal-born neuroblasts during migration are not yet fully understood. Here we report the presence of a primary cilium, and its ultrastructural morphology and spatiotemporal dynamics, in migrating neuroblasts in the postnatal RMS and OB. The primary cilium was observed in migrating neuroblasts in the postnatal RMS and OB in male and female mice and zebrafish, and a male rhesus monkey. Inhibition of intraflagellar transport molecules in migrating neuroblasts impaired their ciliogenesis and rostral migration toward the OB. Serial section transmission electron microscopy revealed that each migrating neuroblast possesses either a pair of centrioles or a basal body with an immature or mature primary cilium. Using immunohistochemistry, live imaging, and serial block-face scanning electron microscopy, we demonstrate that the localization and orientation of the primary cilium are altered depending on the mitotic state, saltatory migration, and deceleration of neuroblasts. Together, our results highlight a close mutual relationship between spatiotemporal regulation of the primary cilium and efficient chain migration of neuroblasts in the postnatal brain.SIGNIFICANCE STATEMENT Immature neurons (neuroblasts) generated in the postnatal brain have a mitotic potential and migrate in chain-like cell aggregates toward the olfactory bulb. Here we report that migrating neuroblasts possess a tiny cellular protrusion called a primary cilium. Immunohistochemical studies with zebrafish, mouse, and monkey brains suggest that the presence of the primary cilium in migrating neuroblasts is evolutionarily conserved. Ciliogenesis in migrating neuroblasts in the rostral migratory stream is suppressed during mitosis and promoted after cell cycle exit. Moreover, live imaging and 3D electron microscopy revealed that ciliary localization and orientation change during saltatory movement of neuroblasts. Our results reveal highly organized dynamics in maturation and positioning of the primary cilium during neuroblast migration that underlie saltatory movement of postnatal-born neuroblasts.


Assuntos
Movimento Celular/fisiologia , Cílios/ultraestrutura , Ventrículos Laterais/ultraestrutura , Células-Tronco Neurais/ultraestrutura , Neurônios/ultraestrutura , Bulbo Olfatório/ultraestrutura , Animais , Feminino , Macaca mulatta , Masculino , Camundongos , Peixe-Zebra
7.
Int J Urol ; 27(2): 149-155, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31721315

RESUMO

OBJECTIVE: To examine the effect of permanent salvage brachytherapy in prostate cancer patients suffering recurrence after three-dimensional conformal external beam radiotherapy. METHODS: The ultra-focal (target lesion alone), hemi-lobe (within a hemi-lobe) or focused whole-gland (focusing on the lesion, but extending into the whole gland) pattern was selected based on the Gleason score for the targeted biopsy, the numbers of positive cores in the targeted and systematic biopsies, and the locations of the positive cores. Novel dosimetry criteria derived from three-dimensional cancer mapping, which was based on targeted magnetic resonance imaging/transrectal ultrasound fusion biopsies, were used in these cases. RESULTS: Permanent salvage brachytherapy was carried out in 13 patients who suffered prostate-specific antigen failure (prostate-specific antigen 2.1-6.8 ng/mL; age range 57-75 years; Gleason score ≤7 [n = 10], Gleason score ≥8 [n = 2] and Gleason score not available [n = 1]) since 2012. The targeted biopsy showed a single focus in three patients. The ultra-focal, hemi-lobe and focused whole-gland patterns were chosen in three, five and five patients, respectively. During the follow-up period (median duration 48 months), prostate-specific antigen failure occurred in zero of three, one of five and three of five of the patients treated with the ultra-focal, hemi-lobe and focused whole-gland patterns, respectively. The 4-year biochemical recurrence-free survival rate was 74%. No grade 3-4 adverse intestinal or urological events occurred. CONCLUSIONS: Targeted fusion biopsy-based three-dimensional cancer mapping should be used for permanent salvage brachytherapy treatment planning to reduce the incidence of treatment-related adverse events while maintaining good oncological outcomes.


Assuntos
Braquiterapia , Neoplasias da Próstata , Idoso , Biópsia , Humanos , Biópsia Guiada por Imagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico por imagem , Antígeno Prostático Específico , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Terapia de Salvação
8.
Biochem Biophys Res Commun ; 510(3): 370-375, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30712943

RESUMO

Serotonin (5-HT) is a major neurotransmitter in mammalian brains and is involved in brain development and psychiatric disorders. The 5-HT1A receptor (5-HT1AR) is a G-protein-coupled receptor (GPCR) associated with an inhibitory G-protein (Gi) with the widest and most abundant expression. It is not known; however, how expression or activity of 5-HTlAR is regulated. We studied here phosphorylation of 5-HT1AR by cyclin-dependent kinase 5 (Cdk5), a neuron-specific membrane-bound Ser/Thr kinase that is activated by binding of the p35 Cdk5 activator. 5-HT1AR was phosphorylated by the Cdk5-p35 complex at Thr314 in the third cytoplasmic loop. The phosphorylation stimulated the degradation of 5-HT1AR by the proteasome, resulting in neutralization of the inhibitory action of 5-HT1AR on intracellular cAMP concentration. These results suggest that Cdk5-p35 modulates 5-HT signaling through phosphorylation-dependent degradation of 5-HTlAR.


Assuntos
Quinase 5 Dependente de Ciclina/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Receptor 5-HT1A de Serotonina/metabolismo , Animais , Células CHO , Células COS , Membrana Celular/metabolismo , Chlorocebus aethiops , Cricetulus , Regulação para Baixo , Células HEK293 , Humanos , Proteínas do Tecido Nervoso/metabolismo , Fosforilação , Serotonina/farmacologia , Transdução de Sinais
9.
Neurochem Res ; 44(7): 1736-1744, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31037609

RESUMO

Recent advances in human induced pluripotent stem cells (hiPSCs) offer new possibilities for biomedical research and clinical applications. Neurons differentiated from hiPSCs may be promising tools to develop novel treatment methods for various neurological diseases. However, the detailed process underlying functional maturation of hiPSC-derived neurons remains poorly understood. Here, we analyze the developmental architecture of hiPSC-derived cortical neurons, iCell GlutaNeurons, focusing on the primary cilium, a single sensory organelle that protrudes from the surface of most growth-arrested vertebrate cells. To characterize the neuronal cilia, cells were cultured for various periods and evaluated immunohistochemically by co-staining with antibodies against ciliary markers Arl13b and MAP2. Primary cilia were detected in neurons within days, and their prevalence and length increased with increasing days in culture. Treatment with the mood stabilizer lithium led to primary cilia length elongation, while treatment with the orexigenic neuropeptide melanin-concentrating hormone caused cilia length shortening in iCell GlutaNeurons. The present findings suggest that iCell GlutaNeurons develop neuronal primary cilia together with the signaling machinery for regulation of cilia length. Our approach to the primary cilium as a cellular antenna can be useful for both assessment of neuronal maturation and validation of pharmaceutical agents in hiPSC-derived neurons.


Assuntos
Cílios/metabolismo , Cílios/ultraestrutura , Células-Tronco Pluripotentes Induzidas/citologia , Neurônios/citologia , Fatores de Ribosilação do ADP/imunologia , Adenilil Ciclases/imunologia , Animais , Anticorpos/imunologia , Linhagem Celular , Cílios/efeitos dos fármacos , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Humanos , Hormônios Hipotalâmicos/farmacologia , Imuno-Histoquímica , Lítio/farmacologia , Melaninas/farmacologia , Proteínas Associadas aos Microtúbulos/imunologia , Neurogênese/fisiologia , Neurônios/efeitos dos fármacos , Hormônios Hipofisários/farmacologia , Ratos Wistar , Receptores de Somatostatina/imunologia
10.
J Nurs Manag ; 26(4): 393-402, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29571223

RESUMO

AIMS: To examine burnout and work engagement among nurses in Japanese long-term care hospitals and their relation to nurses' and organisational work values, and nurse-organisation congruence of such values. BACKGROUND: Nursing managers must help improve nurses' well-being; however, no research has considered strategies to improve staff outcomes in long-term care hospitals. We propose that individual nurse's work values and the congruence of these values with those of their organisations may influence burnout and work engagement. METHODS: We conducted a cross-sectional survey of nurses in long-term care hospitals. Multiple regression analyses were conducted to examine the effects of nurses' work values and nurse-organisation congruence in these values on burnout and work engagement. RESULTS: Higher individual intrinsic and altruistic work values were associated with improvements in nurses' burnout and work engagement. Nurse-organisation non-congruence in altruistic values was associated with lower work engagement, whereas that of intrinsic work values was not associated with either outcome variable. CONCLUSION: Promoting intrinsic and altruistic work values among nurses could be effective for improving both burnout and work engagement. IMPLICATIONS FOR NURSING MANAGEMENT: Opportunities such as case conferences could foster intrinsic and altruistic work values through the review of good care practices and communication between managers/colleagues about feelings and thoughts.


Assuntos
Esgotamento Profissional/epidemiologia , Recursos Humanos de Enfermagem Hospitalar/psicologia , Engajamento no Trabalho , Adulto , Estudos Transversais , Feminino , Humanos , Japão/epidemiologia , Assistência de Longa Duração , Masculino , Pessoa de Meia-Idade , Recursos Humanos de Enfermagem Hospitalar/organização & administração , Recursos Humanos de Enfermagem Hospitalar/estatística & dados numéricos , Fatores de Risco
11.
Gen Comp Endocrinol ; 253: 44-52, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28842217

RESUMO

Primary cilia are specialized microtubule-based organelles. Their importance is highlighted by the gamut of ciliary diseases associated with various syndromes including diabetes and obesity. Primary cilia serve as signaling hubs through selective interactions with ion channels and conventional G-protein-coupled receptors (GPCRs). Melanin-concentrating hormone (MCH) receptor 1 (MCHR1), a key regulator of feeding, is selectively expressed in neuronal primary cilia in distinct regions of the mouse brain. We previously found that MCH acts on ciliary MCHR1 and induces cilia shortening through a Gi/o-dependent Akt pathway with no cell cycle progression. Many factors can participate in cilia length control. However, the mechanisms for how these molecules are relocated and coordinated to activate cilia shortening are poorly understood. In the present study, we investigated the role of cytoskeletal dynamics in regulating MCH-induced cilia shortening using clonal MCHR1-expressing hTERT-RPE1 cells. Pharmacological and biochemical approaches showed that cilia shortening mediated by MCH was associated with increased soluble cytosolic tubulin without changing the total tubulin amount. Enhanced F-actin fiber intensity was also observed in MCH-treated cells. The actions of various pharmacological agents revealed that coordinated actin machinery, especially actin polymerization, was required for MCHR1-mediated cilia shortening. A recent report indicated the existence of actin-regulated machinery for cilia shortening through GPCR agonist-dependent ectosome release. However, our live-cell imaging experiments showed that MCH progressively elicited cilia shortening without exclusion of fluorescence-positive material from the tip. Short cilia phenotypes have been associated with various metabolic disorders. Thus, the present findings may contribute toward better understanding of how the cytoskeleton is involved in the GPCR ligand-triggered cilia shortening with cell mechanical properties that underlies clinical manifestations such as obesity.


Assuntos
Cílios/metabolismo , Citoesqueleto/metabolismo , Receptores do Hormônio Hipofisário/metabolismo , Animais , Corpo Celular/metabolismo , Linhagem Celular , Micropartículas Derivadas de Células/metabolismo , Cílios/efeitos dos fármacos , Citosol/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Humanos , Hormônios Hipotalâmicos/farmacologia , Ligantes , Melaninas/farmacologia , Camundongos , Microtúbulos/metabolismo , Modelos Biológicos , Hormônios Hipofisários/farmacologia , Polimerização , Solubilidade , Tubulina (Proteína)/metabolismo
12.
Gen Comp Endocrinol ; 230-231: 103-9, 2016 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-27080548

RESUMO

Vertebrates produce α-melanocyte-stimulating hormone (α-MSH), which contains an N-terminal acetyl group, and desacetyl-α-MSH, which does not contain an N-terminal acetyl group. In teleosts and amphibians, α-MSH-related peptides stimulate pigment dispersion via melanocortin receptors 1-5 (MC1R-MC5R), which are members of the G-protein-coupled receptor (GPCR) family. We previously reported an interesting phenomenon associated with physiological color changes in the skin of a flatfish, barfin flounder (bf). Specifically, pigments in xanthophores expressing only the bfMC5R gene were dispersed by both α-MSH and desacetyl-α-MSH, whereas those in melanophores expressing both the bfMC1R and bfMC5R genes were dispersed by desacetyl-α-MSH, but not by α-MSH. In this study, we examined whether heterodimers of bfMC1R and bfMC5R can act as significant inhibitory receptors for the N-terminal acetylation of α-MSH in mammalian Chinese hamster ovary cells. Immunofluorescence analyses showed that bfMC1R and bfMC5R were localized together at the plasma membrane when expressed in the same cells. Indeed, after coexpression of Flag-bfMC1R and HA-bfMC5R, immunoprecipitation with anti-Flag antibodies resulted in the presence of anti-HA immunoreactivity in the precipitate, and vice versa. Importantly, cyclic AMP assays showed that cotransfection of bfMC1R with bfMC5R inhibited the cyclic AMP accumulation induced by α-MSH to a greater extent than that observed after transfection of bfMC1R alone. Of note, this inhibitory response was not caused by desacetyl-α-MSH. Thus, we show a ligand-dependent signaling through functional heterodimerization of MC1R and MC5R in mammalian cells. The ligand-selective receptor complex also provide the first mechanistic implication that may play a role in the control of color change in teleosts.


Assuntos
Linguado/fisiologia , Multimerização Proteica , Receptor Tipo 1 de Melanocortina/metabolismo , Receptores de Melanocortina/metabolismo , Pigmentação da Pele , Animais , Células CHO , Cricetinae , Cricetulus , AMP Cíclico/metabolismo , Linguado/genética , Linguado/metabolismo , Ligantes , Melanóforos/metabolismo , Ligação Proteica/genética , Multimerização Proteica/genética , Receptor Tipo 1 de Melanocortina/genética , Receptores de Melanocortina/genética , Transdução de Sinais/genética , Pigmentação da Pele/genética , alfa-MSH/metabolismo
13.
Biochem Biophys Res Commun ; 467(4): 778-84, 2015 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-26482848

RESUMO

The candidate tumor suppressor gene RASSF1A (Ras-association domain family 1, isoform A) is inactivated in many types of adult and childhood cancers. However, the mechanisms by which RASSF1A exerts tumor suppressive functions have yet to be elucidated. In this report, we sought to identify candidate proteins that interact with RASSF1A using proteomic screening. Using peptide mass fingerprinting, we identified protein arginine N-methyltransferase 5 (PRMT5), a type II protein arginine N-methyltransferase that monomethylates and symmetrically dimethylates arginine residues, as a novel protein that interacts with RASSF1A. The association between the two proteins was confirmed by co-immunoprecipitation and immunofluorescence staining. Co-expressing RASSF1A and PRMT5 led to a redistribution of PRMT5 from the cytosol to stabilized microtubules, where RASSF1A and PRMT5 became co-localized. Our results demonstrate that PRMT5 translocates to bundled microtubules on stabilization by RASSF1A expression. Our results show that the tumor suppressor RASSF1A interacts with PRMT5 in vivo and in vitro. Notably, this is the first demonstration of RASSF1A-dependent microtubule recruitment of PRMT5, suggesting a novel role for RASSF1A in the anchoring of cytosolic PRMT5 to microtubules.


Assuntos
Microtúbulos/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Células COS , Chlorocebus aethiops , Citosol/metabolismo , Células HEK293/metabolismo , Humanos , Transporte Proteico , Proteína-Arginina N-Metiltransferases/genética , Proteômica/métodos , Proteínas Supressoras de Tumor/genética
14.
Gen Comp Endocrinol ; 212: 114-23, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24662390

RESUMO

Melanin-concentrating hormone (MCH) mainly regulates feeding in mammals and pigmentation in teleosts. It acts via two G-protein-coupled receptors, MCH receptor 1 (MCHR1) and MCHR2. Although many studies exploring the MCH system in teleosts and mammals have been carried out, studies on other organisms are limited. In this study, we cloned and characterized four MCHR subtypes from the diploid species Xenopus tropicalis (X-MCHRs; X-MCHR1a, R1b, R2a, and R2b). According to a phylogenetic tree of the X-MCHRs, X-MCHR1a and R2a are close to mammalian MCHRs, while X-MCHR1b and R2b are close to teleostean MCHRs. We previously reported that the G-protein coupling capacity of the MCHR subtypes differed between mammals (R1: Gαi/o and Gαq; R2: Gαq) and teleosts (R1: Gαq; R2: Gαi/o and Gαq) in mammalian cell-based assays. By using Ca(2+) mobilization assays with pertussis toxin in CHO dhfr(-) cells, we found that X-MCHR1a promiscuously coupled to both Gαi/o and Gαq, while X-MCHR1b and R2a exclusively coupled to Gαq. However, no Ca(2+) influx was detected in cells transfected with X-MCHR2b. Reverse transcription-PCR showed that the X-MCHR mRNAs were expressed in various tissues. In particular, both X-MCHR1b and R2b were exclusively found in melanophores of the dorsal skin. In skin pigment migration assays, melanophores were weakly aggregated at low concentrations but dispersed at high concentrations of MCH, suggesting possible interactions between X-MCHR1b and R2b for the regulation of body color. These findings demonstrate that X. tropicalis has four characteristic MCHRs and will be useful for elucidating the nature of MCHR evolution among vertebrates.


Assuntos
Regulação da Expressão Gênica , Hormônios Hipotalâmicos/genética , Melaninas/genética , Hormônios Hipofisários/genética , Receptores do Hormônio Hipofisário/genética , Transdução de Sinais , Xenopus/genética , Sequência de Aminoácidos , Animais , Western Blotting , Células CHO , Cálcio/metabolismo , Clonagem Molecular , Cricetulus , Hormônios Hipotalâmicos/metabolismo , Melaninas/metabolismo , Melanóforos/metabolismo , Dados de Sequência Molecular , Filogenia , Hormônios Hipofisários/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptores do Hormônio Hipofisário/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Pele/metabolismo , Xenopus/crescimento & desenvolvimento
15.
Gen Comp Endocrinol ; 214: 140-8, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25058366

RESUMO

In teleosts, melanin-concentrating hormone (MCH) plays a key role in skin color changes. MCH is released into general circulation from the neurohypophysis, which causes pigment aggregation in the skin chromatophores. Recently, a novel MCH (MCH2) precursor gene, which is orthologous to the mammalian MCH precursor gene, has been identified in some teleosts using genomic data mining. The physiological function of MCH2 remains unclear. In the present study, we cloned the cDNA for MCH2 from barfin flounder, Verasper moseri. The putative prepro-MCH2 contains 25 amino acids of MCH2 peptide region. Liquid chromatography-electrospray ionization mass spectrometry with a high resolution mass analyzer were used for confirming the amino acid sequences of MCH1 and MCH2 peptides from the pituitary extract. In vitro synthesized MCH1 and MCH2 induced pigment aggregation in a dose-dependent manner. A mammalian cell-based assay indicated that both MCH1 and MCH2 functionally interacted with both the MCH receptor types 1 and 2. Mch1 and mch2 are exclusively expressed in the brain and pituitary. The levels of brain mch2 transcript were three times higher in the fish that were chronically acclimated to a white background than those acclimated to a black background. These results suggest that in V. moseri, MCH1 and MCH2 are involved in the response to changes in background colors, during the process of chromatophore control.


Assuntos
Adaptação Fisiológica/fisiologia , Cor , Linguado/fisiologia , Hormônios Hipotalâmicos/metabolismo , Melaninas/metabolismo , Fragmentos de Peptídeos/análise , Hipófise/metabolismo , Hormônios Hipofisários/metabolismo , Pigmentação da Pele/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Cromatografia Líquida , Clonagem Molecular , Dados de Sequência Molecular , RNA Mensageiro , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Espectrometria de Massas por Ionização por Electrospray , Distribuição Tecidual
16.
Artigo em Inglês | MEDLINE | ID: mdl-38889951

RESUMO

OBJECTIVES: This study explored the information needs and requirements of patients with pancreatic cancer (PPCs) and their families through patients' and families' views and preferences (PVPs) collected by healthcare professionals (HCPs) and to identify differences in PVPs by profession. METHODS: We conducted an anonymous web-based survey of HCPs in cancer care hospitals in Japan, posing specific questions from patients or families regarding pancreatic cancer within the past year. We qualitatively analysed the data and classified them into several categories according to their content. We also compared the percentage of PVPs in each category in the medical profession. RESULTS: We collected 893 PVPs from 353 HCPs and classified them into 15 topics within 5 categories: (1) treatment and care, (2) characteristics of the disease, (3) daily life, (4) feelings of patients or families and (5) communication with HCPs/peer support information. Physicians, nurses and pharmacists received mainly PVPs in categories 1 and 2. Characteristically, cancer counsellors received PVPs in all categories, with higher frequencies for categories 3-5. CONCLUSIONS: PPCs and families have diverse PVPs, and appear to select different HCPs for consultation based on their specific concerns. Each HCP should recognise that their individual experience may be insufficient in understanding the full spectrum of PVPs; however, cancer counsellors tend to have a broader awareness of them. To support PPCs and families, HCPs should appropriately collaborate with each other, considering that HCPs like cancer counsellors who do not provide direct treatment still play an important role in providing holistic support.

17.
J Neurol Sci ; 457: 122896, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38290377

RESUMO

BACKGROUND: Information on the incidence and risk factors of deep vein thrombosis (DVT) in neurodegenerative diseases is limited. We aimed to determine the incidence of DVT among neurodegenerative disorders (amyotrophic lateral sclerosis [ALS], Parkinson's disease [PD], multiple system atrophy [MSA], and progressive supranuclear palsy [PSP]-corticobasal syndrome [CBS]) and the risk factors for the development of DVT. METHODS: Overall, 229 hospitalized patients with neurodegenerative diseases (65 patients with ALS, 61 with PD, 53 with MSA, and 50 with PSP-CBS) were included in this study. D-dimer value and ultrasonography of the leg vein were assessed to determine the presence or absence of leg DVT. We compared the DVT incidence among each disease group. To identify the risk factors for DVT, a multivariate analysis was performed. RESULTS: Of 229 patients, 34 had leg DVT; the incidence was significantly higher in patients with PD (38%) than in those with ALS (2%), MSA (5%), or PSP-CBS (4%). Patients with DVT were older, had a smaller waist circumference, had a longer disease duration, and had a high blood pressure (BP) variability. Multivariate analysis revealed that a PD diagnosis and female sex, with a high BP variability were predictive of leg DVT. CONCLUSIONS: Among the neurodegenerative diseases, the DVT incidence was markedly higher in PD than in ALS, MSA, and PSP-CBS. Several risk factors have been identified in patients with leg DVT. Recognition of these risk factors will improve patient care and guide the appropriate use of anticoagulants.


Assuntos
Esclerose Lateral Amiotrófica , Atrofia de Múltiplos Sistemas , Doença de Parkinson , Paralisia Supranuclear Progressiva , Trombose Venosa , Humanos , Feminino , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/epidemiologia , Incidência , Fatores de Risco , Trombose Venosa/diagnóstico por imagem , Trombose Venosa/epidemiologia
18.
Gen Comp Endocrinol ; 188: 159-65, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-23467069

RESUMO

Melanin-concentrating hormone (MCH) is the natural peptide ligand for MCHR1 and MCHR2, which belong to the G protein-coupled receptor (GPCR) superfamily. The MCH-MCHR1 system is involved in the regulation of feeding, energy homeostasis and emotional processing in rodents. Recently, MCHR1 expression was discovered in neuronal immotile primary cilia of the central nervous system in mice. The cilium has an important chemosensory function in many types of cell and ciliary dysfunction is associated with cliopathies such as polycystic kidney disease, retinal dystrophy, and obesity. The targeting sequence of ciliary membrane proteins is thought to be unique. Although these sequences have been predicted in the cytoplasmic third loop and/or C-terminus of GPCRs, little is known about the characteristics of MCHR1. We thus explored the molecular mechanisms of MCHR1 targeting by transiently expressing a series of MCHR1 mutants into ciliated hRPE1 cells and evaluated the effects of these mutations on the ciliary localization of the heterologous receptor. This approach demonstrated that an Ala-to-Gly mutation (A242G) within the third intracellular loop induced a significant reduction in ciliary localization of the receptor without affecting the ciliogenesis. In contrast, no C-terminal truncation mutant had any effect on ciliary localization or cilia length. This study provides a potential molecular link between defective cilia and clinical manifestations such as obesity.


Assuntos
Cílios/metabolismo , Receptores de Somatostatina/metabolismo , Animais , Linhagem Celular , Humanos , Microscopia de Fluorescência , Mutação , Ratos
19.
Gen Comp Endocrinol ; 181: 229-34, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23168086

RESUMO

In teleosts, as their names suggest, the main target cells of melanocyte-stimulating hormone (MSH) and melanin-concentrating hormone (MCH) are the chromatophores in the skin, where these peptide hormones play opposing roles in regulating pigment migration. These effects are obvious especially when their activities are examined in vitro. On the contrary, while MCH also exhibits activity in vivo, MSH does not always stimulate pigment dispersion in vivo because of predominant sympathetic nervous system. A series of our investigations indicates that this is also the case in barfin flounder, Verasper moseri. Interestingly, we observed that mch expression and the tissue contents of MCH can be easily influenced by changes in environmental color conditions, while gene expression and tissue contents related to MSH scarcely respond to color changes. Transcripts of MSH and MCH receptor genes have been identified in a variety of tissues of this fish species, suggesting that these are multifunctional peptide hormones. Nevertheless, chromatophores in the skin still offer important clues in the efforts to elucidate the functions of melanotropic peptides. Herein, we review the most recent advancements of our studies on MSH and MCH and their receptors in the barfin flounder and discuss the interrelations between these peptides, focusing on their roles in influencing pigment migration in the skin.


Assuntos
Linguado/metabolismo , Hormônios Hipotalâmicos/metabolismo , Melaninas/metabolismo , Hormônios Estimuladores de Melanócitos/metabolismo , Hormônios Hipofisários/metabolismo , Animais , Linguado/fisiologia , Melanóforos/metabolismo , Pigmentação da Pele/fisiologia
20.
Methods Cell Biol ; 175: 69-83, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36967146

RESUMO

The primary cilium is a structural organelle present in most mammalian cells. Primary cilia are enriched with a unique protein repertoire distinct from that of the cytosol and the plasma membrane. Such a highly organized microenvironment creates effective machinery for translating extracellular cues into intracellular signals. G protein-coupled receptors (GPCRs) are key receptors in sensing environmental stimuli transmitted via a second messenger into a cellular response. Recent data has demonstrated that a limited number of non-olfactory GPCRs, including melanin-concentrating hormone receptor 1 (MCHR1), are preferentially localized to ciliary membranes of several mammalian cell types, including neuronal cells. Evidence was accumulated to support the functional importance of ciliary-GPCR signaling accompanying ciliary structural changes using cilia-specific cell and molecular biology techniques. Thus, cilia are now considered to function as a unique sensory platform for the integration of GPCR signaling and various cytoplasmic domains. Dissociated neurons expressing ciliary-GPCRs can be a useful tool for examining ciliary dynamics. However, losing preexisting neuronal connectivity may alter neuronal ciliary morphology, such as abnormal elongation. Brain slices prepared under ex vitro conditions are a powerful approach that maintains the cytoarchitecture, enabling researchers to have accurate control over experimental conditions and to study individual cells from subregions of the brain. Here, we present a detailed description of our novel modified method for organotypic culture of rat brain slice and a validated immunostaining protocol to characterize ciliary-GPCR dynamics in coupling with neuropeptides or aminergic activation.


Assuntos
Encéfalo , Receptores Acoplados a Proteínas G , Ratos , Animais , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Membrana Celular/metabolismo , Encéfalo/metabolismo , Cílios/metabolismo , Mamíferos/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA