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1.
Cell ; 184(24): 5869-5885.e25, 2021 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-34758294

RESUMO

RTN4-binding proteins were widely studied as "NoGo" receptors, but their physiological interactors and roles remain elusive. Similarly, BAI adhesion-GPCRs were associated with numerous activities, but their ligands and functions remain unclear. Using unbiased approaches, we observed an unexpected convergence: RTN4 receptors are high-affinity ligands for BAI adhesion-GPCRs. A single thrombospondin type 1-repeat (TSR) domain of BAIs binds to the leucine-rich repeat domain of all three RTN4-receptor isoforms with nanomolar affinity. In the 1.65 Å crystal structure of the BAI1/RTN4-receptor complex, C-mannosylation of tryptophan and O-fucosylation of threonine in the BAI TSR-domains creates a RTN4-receptor/BAI interface shaped by unusual glycoconjugates that enables high-affinity interactions. In human neurons, RTN4 receptors regulate dendritic arborization, axonal elongation, and synapse formation by differential binding to glial versus neuronal BAIs, thereby controlling neural network activity. Thus, BAI binding to RTN4/NoGo receptors represents a receptor-ligand axis that, enabled by rare post-translational modifications, controls development of synaptic circuits.


Assuntos
Inibidores da Angiogênese/metabolismo , Encéfalo/metabolismo , Neurogênese , Neurônios/metabolismo , Proteínas Nogo/metabolismo , Receptores Nogo/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Adipocinas/metabolismo , Sequência de Aminoácidos , Animais , Axônios/metabolismo , Adesão Celular , Moléculas de Adesão Celular Neuronais/metabolismo , Complemento C1q/metabolismo , Dendritos/metabolismo , Glicosilação , Células HEK293 , Células-Tronco Embrionárias Humanas/metabolismo , Humanos , Ligantes , Camundongos Endogâmicos C57BL , Rede Nervosa/metabolismo , Polissacarídeos/metabolismo , Ligação Proteica , Domínios Proteicos , Deleção de Sequência , Sinapses/metabolismo , Transmissão Sináptica/fisiologia
2.
Glia ; 72(6): 1067-1081, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38497356

RESUMO

Alzheimer's Disease (AD) pathogenesis is thought to begin up to 20 years before cognitive symptoms appear, suggesting the need for more sensitive diagnostic biomarkers of AD. In this report, we demonstrated pathological changes in retinal Müller glia significantly earlier than amyloid pathology in AD mouse models. By utilizing the knock-in NLGF mouse model, we surprisingly discovered an increase in reticulon 3 (RTN3) protein levels in the NLGF retina as early as postnatal day 30 (P30). Despite RTN3 being a canonically neuronal protein, this increase was noted in the retinal Müller glia, confirmed by immunohistochemical characterization. Further unbiased transcriptomic assays of the P30 NLGF retina revealed that retinal Müller glia were the most sensitive responding cells in this mouse retina, compared with other cell types including photoreceptor cells and ganglion neurons. Pathway analyses of differentially expressed genes in glia cells showed activation of ER stress response via the upregulation of unfolded protein response (UPR) proteins such as ATF4 and CHOP. Early elevation of RTN3 in response to challenges by toxic Aß likely facilitated UPR. Altogether, these findings suggest that Müller glia act as a sentinel for AD pathology in the retina and should aid for both intervention and diagnosis.


Assuntos
Doença de Alzheimer , Animais , Camundongos , Doença de Alzheimer/patologia , Retina , Neurônios/metabolismo , Modelos Animais de Doenças , Proteínas Amiloidogênicas/metabolismo , Neuroglia/metabolismo , Encéfalo/metabolismo , Células Ependimogliais/metabolismo
3.
Epilepsy Behav ; 157: 109848, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38823073

RESUMO

OSA is known to increase the risk for SUDEP in persons with epilepsy, but the relationship between these two factors is not clear. Also, there is no study showing the acute responses to obstructive apnea in a chronic epilepsy model. Therefore, this study aimed to characterize cardiorespiratory responses to obstructive apnea and chemoreceptor stimulation in rats. In addition, we analyzed respiratory centers in the brain stem by immunohistochemistry. Epilepsy was induced with pilocarpine. About 30-60 days after the first spontaneous seizure, tracheal and thoracic balloons, and electrodes for recording the electroencephalogram, electromyogram, and electrocardiogram were implanted. Intermittent apneas were made by inflation of the tracheal balloon during wakefulness, NREM sleep, and REM sleep. During apnea, respiratory effort increased, and heart rate fell, especially with apneas made during wakefulness, both in control rats and rats with epilepsy. Latency to awake from apnea was longer with apneas made during REM than NREM, but rats with epilepsy awoke more rapidly than controls with apneas made during REM sleep. Rats with epilepsy also had less REM sleep. Cardiorespiratory responses to stimulation of carotid chemoreceptors with cyanide were similar in rats with epilepsy and controls. Immunohistochemical analysis of Phox2b, tryptophan hydroxylase, and NK1 in brain stem nuclei involved in breathing and sleep (retrotrapezoid nucleus, pre-Bötzinger complex, Bötzinger complex, and caudal raphe nuclei) revealed no differences between control rats and rats with epilepsy. In conclusion, our study showed that rats with epilepsy had a decrease in the latency to awaken from apneas during REM sleep, which may be related to neuroplasticity in some other brain regions related to respiratory control, awakening mechanisms, and autonomic modulation.


Assuntos
Modelos Animais de Doenças , Eletroencefalografia , Epilepsia , Apneia Obstrutiva do Sono , Vigília , Animais , Vigília/fisiologia , Masculino , Epilepsia/fisiopatologia , Apneia Obstrutiva do Sono/fisiopatologia , Apneia Obstrutiva do Sono/complicações , Ratos , Doença Crônica , Pilocarpina/toxicidade , Tronco Encefálico/fisiopatologia , Frequência Cardíaca/fisiologia , Eletromiografia , Ratos Sprague-Dawley , Ratos Wistar
4.
Cryobiology ; 112: 104544, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37211323

RESUMO

Mild hypothermia is proven neuroprotective in clinical practice. While hypothermia leads to the decrease of global protein synthesis rate, it upregulates a small subset of protein including RNA-binding motif protein 3 (RBM3). In this study, we treated mouse neuroblastoma cells (N2a) with mild hypothermia before oxygen-glucose deprivation/reoxygenation (OGD/R) and discovered the decrease of apoptosis rate, down-regulation of apoptosis-associated protein and enhancement of cell viability. Overexpression of RBM3 via plasmid exerted similar effect while silencing RBM3 by siRNAs partially reversed the protective effect exerted by mild hypothermia pretreatment. The protein level of Reticulon 3(RTN3), a downstream gene of RBM3, also increased after mild hypothermia pretreatment. Silencing RTN3 weakened the protective effect of mild hypothermia pretreatment or RBM3 overexpression. Also, the protein level of autophagy gene LC3B increased after OGD/R or RBM3 overexpression while silencing RTN3 decreased this trend. Furthermore, immunofluorescence observed enhanced fluorescence signal of LC3B and RTN3 as well as a large number of overlaps after RBM3 overexpressing. In conclusion, RBM3 plays a cellular protective role by regulating apoptosis and viability via its downstream gene RTN3 in the hypothermia OGD/R cell model and autophagy may participate in it.


Assuntos
Hipotermia , Animais , Camundongos , Apoptose , Criopreservação/métodos , Glucose , Hipotermia/genética , Hipotermia/metabolismo , Oxigênio/metabolismo , Motivos de Ligação ao RNA , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
5.
Adv Exp Med Biol ; 1427: 107-114, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37322341

RESUMO

Heart failure (HF) is a prevalent disease in elderly population. Potentiation of the ventilatory chemoreflex drive plays a pivotal role in disease progression, at least in part, through their contribution to the generation/maintenance of breathing disorders. Peripheral and central chemoreflexes are mainly regulated by carotid body (CB) and the retrotrapezoid nuclei (RTN), respectively. Recent evidence showed an enhanced central chemoreflex drive in rats with nonischemic HF along with breathing disorders. Importantly, increase activity from RTN chemoreceptors contribute to the potentiation of central chemoreflex response to hypercapnia. The precise mechanism driving RTN potentiation in HF is still elusive. Since interdependency of RTN and CB chemoreceptors has been described, we hypothesized that CB afferent activity is required to increase RTN chemosensitivity in the setting of HF. Accordingly, we studied central/peripheral chemoreflex drive and breathing disorders in HF rats with and without functional CBs (CB denervation). We found that CB afferent activity was required to increase central chemoreflex drive in HF. Indeed, CB denervation restored normal central chemoreflex drive and reduced the incidence of apneas by twofold. Our results support the notion that CB afferent activity plays an important role in central chemoreflex potentiation in rats with HF.


Assuntos
Corpo Carotídeo , Insuficiência Cardíaca , Idoso , Ratos , Humanos , Animais , Células Quimiorreceptoras/fisiologia , Corpo Carotídeo/fisiologia , Fenômenos Fisiológicos Respiratórios , Hipercapnia
6.
Sensors (Basel) ; 23(18)2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37766015

RESUMO

In this work, the degradation of the random telegraph noise (RTN) and the threshold voltage (Vt) shift of an 8.3Mpixel stacked CMOS image sensor (CIS) under hot carrier injection (HCI) stress are investigated. We report for the first time the significant statistical differences between these two device aging phenomena. The Vt shift is relatively uniform among all the devices and gradually evolves over time. By contrast, the RTN degradation is evidently abrupt and random in nature and only happens to a small percentage of devices. The generation of new RTN traps by HCI during times of stress is demonstrated both statistically and on the individual device level. An improved method is developed to identify RTN devices with degenerate amplitude histograms.

7.
Int J Mol Sci ; 24(21)2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37958606

RESUMO

Schizophrenia is one of the most serious psychiatric disorders and is characterized by reductions in both brain volume and spine density in the frontal cortex. RhoA belongs to the RAS homolog (Rho) family and plays critical roles in neuronal development and structural plasticity via Rho-kinase. RhoA activity is regulated by GTPase-activating proteins (GAPs) and guanine nucleotide exchange factors (GEFs). Several variants in GAPs and GEFs associated with RhoA have been reported to be significantly associated with schizophrenia. Moreover, several mouse models carrying schizophrenia-associated gene variants involved in RhoA/Rho-kinase signaling have been developed. In this review, we summarize clinical evidence showing that variants in genes regulating RhoA activity are associated with schizophrenia. In the last half of the review, we discuss preclinical evidence indicating that RhoA/Rho-kinase is a potential therapeutic target of schizophrenia. In particular, Rho-kinase inhibitors exhibit anti-psychotic-like effects not only in Arhgap10 S490P/NHEJ mice, but also in pharmacologic models of schizophrenia (methamphetamine- and MK-801-treated mice). Accordingly, we propose that Rho-kinase inhibitors may have antipsychotic effects and reduce cognitive deficits in schizophrenia despite the presence or absence of genetic variants in small GTPase signaling pathways.


Assuntos
Proteínas Monoméricas de Ligação ao GTP , Esquizofrenia , Humanos , Camundongos , Animais , Quinases Associadas a rho/metabolismo , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Esquizofrenia/tratamento farmacológico , Esquizofrenia/genética , Transdução de Sinais , Proteína rhoA de Ligação ao GTP/genética , Proteína rhoA de Ligação ao GTP/metabolismo , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Genômica
8.
J Gene Med ; 23(5): e3314, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33491257

RESUMO

BACKGROUND: Dysregulation of long non-coding RNAs (lncRNAs) is related to the occurrence of osteoarthritis (OA). In the present study, we explored the role of LINC02288 and its regulatory mechanism in OA development. METHODS: GSE113825 was obtained from Gene Expression Omnibus (GEO) database and analyzed to identify the differentially expressed lncRNAs in OA. Gene enrichment analyses and Kyoto Encyclopedia of Genes and Genomes biological process analysis were performed through Metascape (http://metascape.org/gp). The interactions among LINC02288, miR-374a-3p and RTN3 were determined using RNA immunoprecipitation (RIP) assays and dual luciferase reporter assays. Chondrocyte apoptosis was examined using flow cytometry. Western blot assays were conducted to assess the pro-apoptotic and anti-apoptotic markers. RESULTS: We identified a total of 4,491 differentially expressed lncRNAs. We focused on LINC02288 as the top-ranked up-regulated lncRNA in OA as indicated by a significant p-value. LINC02288 was significantly up-regulated, which was further verified by a real-time polymerase chain reaction. Down-regulation of LINC02288 significantly reduced the apoptosis of OA chondrocytes induced by interleukin-1ß and the production of pro-inflammatory cytokines. These effects were further verified in an OA rat model. An RIP assay and dual luciferase assay further confirmed that LINC02288 served as a sponge of miR-374a-3p. Moreover, the overexpression of RTN3 could partially reverse the effects of LINC02288 knockdown, mediating inhibitory effects on chondrocyte apoptosis and the inflammatory response. Down-regulation of LINC02288 alleviated OA development in an in vivo OA animal model. CONCLUSIONS: Our findings indicate that LINC02288 contributes to OA progression by targeting the miR-374a-3p/RTN3 axis, which might provide a promising molecular therapy strategy for OA.


Assuntos
Proteínas de Transporte/genética , Proteínas de Membrana/genética , MicroRNAs/genética , Proteínas do Tecido Nervoso/genética , Osteoartrite/genética , RNA Longo não Codificante/genética , Animais , Apoptose/genética , Proliferação de Células/genética , Condrócitos/metabolismo , Condrócitos/patologia , Modelos Animais de Doenças , Humanos , Inflamação/genética , Inflamação/patologia , Interleucina-1beta/genética , Osteoartrite/patologia , Ratos
9.
Biochem Biophys Res Commun ; 581: 96-102, 2021 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-34662809

RESUMO

OBJECTIVE: To examine the mechanisms of Nogo-B (RTN4B) in the protection of blood-retinal barrier in experimental diabetic retinopathy. METHODS: The level of Nogo-B in vitreous and plasma samples was detected with ELISA. Diabetes was induced in Sprague-Dawley rats with intraperitoneal injection of streptozotocin. The rats were injected intravitreally with adeno-associated virus (AAV) for knockdown the expression of Nogo-B in retina or/and as AAV negative control. The permeability of blood-retinal barrier was detected with Rhodamine-B-dextran leakage assay. The expressions of Nogo-B, junctional proteins, inflammatory factors and signaling pathways were examined with Western blot and quantitative real-time PCR. RESULTS: Nogo-B expression was significantly upregulated in clinical samples and experimental diabetic rat models. Under normal condition, Nogo-B knockdown resulted in the increased permeability of retinal blood vessels. In diabetic rat retinas, the vascular leakage was increased significantly, which was partially decreased by Nogo-B knockdown through increasing p/t-Src (Tyr529) and p/t-Akt (Ser473), and decreasing p/t-ERK1/2. CONCLUSION: Nogo-B was increased in diabetic retinopathy and silencing Nogo-B is a promising therapy for diabetic retinopathy.


Assuntos
Diabetes Mellitus Experimental/genética , Retinopatia Diabética/genética , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Receptores de Superfície Celular/genética , Quinases da Família src/genética , Animais , Barreira Hematorretiniana/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Retinopatia Diabética/metabolismo , Retinopatia Diabética/patologia , Retinopatia Diabética/terapia , Regulação da Expressão Gênica , Masculino , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Superfície Celular/antagonistas & inibidores , Receptores de Superfície Celular/metabolismo , Retina/metabolismo , Retina/patologia , Vasos Retinianos/metabolismo , Vasos Retinianos/patologia , Transdução de Sinais , Estreptozocina/administração & dosagem , Quinases da Família src/metabolismo
10.
Cell Mol Neurobiol ; 41(6): 1157-1174, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32504327

RESUMO

In the last few decades, cytoplasmic organellar dysfunction, such as that of the endoplasmic reticulum (ER), has created a new area of research interest towards the development of serious health maladies including neurodegenerative diseases. In this context, the extensively dispersed family of ER-localized proteins, i.e. reticulons (RTNs), is gaining interest because of its regulative control over neural regeneration. As most neurodegenerative diseases are pathologically manifested with the accretion of misfolded proteins with subsequent induction of ER stress, the regulatory role of RTNs in neural dysfunction cannot be ignored. With the limited information available in the literature, delineation of the functional connection between rising consequences of neurodegenerative diseases and RTNs need to be elucidated. In this review, we provide a broad overview on the recently revealed regulatory roles of reticulons in the pathophysiology of several health maladies, with special emphasis on neurodegeneration. Additionally, we have also recapitulated the decisive role of RTN4 in neurite regeneration and highlighted how neurodegeneration and proteinopathies are mechanistically linked with each other through specific RTN paralogues. With the recent findings advocating zebrafish Rtn4b (a mammalian Nogo-A homologue) downregulation following central nervous system (CNS) lesion, RTNs provides new insight into the CNS regeneration. However, there are controversies with respect to the role of Rtn4b in zebrafish CNS regeneration. Given these controversies, the connection between the unique regenerative capabilities of zebrafish CNS by distinct compensatory mechanisms and Rtn4b signalling pathway could shed light on the development of new therapeutic strategies against serious neurodegenerative diseases.


Assuntos
Regeneração Nervosa/fisiologia , Proteínas do Tecido Nervoso/metabolismo , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/terapia , Neurogênese/fisiologia , Animais , Humanos , Proteínas da Mielina/metabolismo , Proteínas Nogo/metabolismo , Peixe-Zebra , Proteínas de Peixe-Zebra/metabolismo
11.
Am J Med Genet A ; 185(1): 203-207, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33037779

RESUMO

Inherited optic neuropathies (IONs) are neurodegenerative disorders characterized by optic atrophy with or without extraocular manifestations. Optic atrophy-10 (OPA10) is an autosomal recessive ION recently reported to be caused by mutations in RTN4IP1, which encodes reticulon 4 interacting protein 1 (RTN4IP1), a mitochondrial ubiquinol oxydo-reductase. Here we report novel compound heterozygous mutations in RTN4IP1 in a male proband with developmental delay, epilepsy, optic atrophy, ataxia, and choreoathetosis. Workup was notable for transiently elevated lactate and lactate-to-pyruvate ratio, brain magnetic resonance imaging with optic atrophy and T2 signal abnormalities, and a nondiagnostic initial genetic workup, including chromosomal microarray and mitochondrial panel testing. Exome sequencing identified a paternally inherited missense variant (c.263T>G, p.Val88Gly) predicted to be deleterious and a maternally inherited deletion encompassing RTN4IP1. To our knowledge, this is the first report of a non-single nucleotide pathogenic variant associated with OPA10. This case highlights the expanding phenotypic spectrum of OPA10, the association between "syndromic" cases and severe RTN4IP1 mutations, and the importance of nonbiased genetic testing, such as ES, to analyze multiple genes and variants types, in patients suspected of having genetic disease.


Assuntos
Proteínas de Transporte/genética , Deficiências do Desenvolvimento/genética , Epilepsia/genética , Proteínas Mitocondriais/genética , Atrofia Óptica/genética , Ataxia/diagnóstico por imagem , Ataxia/genética , Ataxia/patologia , Proteínas de Transporte/ultraestrutura , Pré-Escolar , Deficiências do Desenvolvimento/diagnóstico por imagem , Deficiências do Desenvolvimento/patologia , Epilepsia/diagnóstico por imagem , Epilepsia/patologia , Exoma/genética , Feminino , Predisposição Genética para Doença , Testes Genéticos/métodos , Humanos , Lactente , Recém-Nascido , Imageamento por Ressonância Magnética , Masculino , Proteínas Mitocondriais/ultraestrutura , Mutação/genética , Atrofia Óptica/diagnóstico por imagem , Atrofia Óptica/patologia , Linhagem , Conformação Proteica , Relação Estrutura-Atividade , Sequenciamento do Exoma
12.
Acta Biochim Biophys Sin (Shanghai) ; 53(2): 170-178, 2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33372676

RESUMO

It has been widely accepted that autophagic cell death exacerbates the progression of cerebral ischemia/reperfusion (I/R). Our previous study revealed that overexpression of reticulon protein 1-C (RTN1-C) is involved in cerebral I/R injury. However, the underlying mechanisms have not been studied intensively. This study was designed to evaluate the effect of RTN1-C on autophagy under cerebral I/R. Using an in vitro oxygen-glucose deprivation followed by reoxygenation and a transient middle cerebral artery occlusion model in rats, we found that the expression of RTN1-C protein was significantly upregulated. We also revealed that RTN1-C knockdown suppressed overactivated autophagy both in vivo and in vitro, as indicated by decreased expressions of autophagic proteins. The number of Beclin-1/propidium iodide-positive cells was significantly less in the LV-shRTN1-C group than in the LV-shNC group. In addition, rapamycin, an activator of autophagy, aggravated cerebral I/R injury. RTN1-C knockdown reduced brain infarct volume, improved neurological deficits, and attenuated cell vulnerability to cerebral I/R injury after rapamycin treatment. Taken together, our findings demonstrated that the modulation of autophagy from RTN1-C may play vital roles in cerebral I/R injury, providing a potential therapeutic treatment for ischemic brain injury.


Assuntos
Autofagia , Infarto Encefálico/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Traumatismo por Reperfusão/metabolismo , Animais , Infarto Encefálico/genética , Infarto Encefálico/patologia , Deleção de Genes , Masculino , Proteínas do Tecido Nervoso/genética , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/patologia
13.
Proc Natl Acad Sci U S A ; 115(23): E5344-E5352, 2018 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-29784816

RESUMO

The neurotropic parasite Toxoplasma gondii is a globally distributed parasitic protozoan among mammalian hosts, including humans. During the course of infection, the CNS is the most commonly damaged organ among invaded tissues. The polymorphic rhoptry protein 18 (ROP18) is a key serine (Ser)/threonine (Thr) kinase that phosphorylates host proteins to modulate acute virulence. However, the basis of neurotropism and the specific substrates through which ROP18 exerts neuropathogenesis remain unknown. Using mass spectrometry, we performed proteomic analysis of proteins that selectively bind to active ROP18 and identified RTN1-C, an endoplasmic reticulum (ER) protein that is preferentially expressed in the CNS. We demonstrated that ROP18 is associated with the N-terminal portion of RTN1-C and specifically phosphorylates RTN1-C at Ser7/134 and Thr4/8/118. ROP18 phosphorylation of RTN1-C triggers ER stress-mediated apoptosis in neural cells. Remarkably, ROP18 phosphorylation of RTN1-C enhances glucose-regulated protein 78 (GRP78) acetylation by attenuating the activity of histone deacetylase (HDAC), and this event is associated with an increase of neural apoptosis. These results clearly demonstrate that both RTN1-C and HDACs are involved in T. gondii ROP18-mediated pathogenesis of encephalitis during Toxoplasma infection.


Assuntos
Síndrome da Imunodeficiência Adquirida/microbiologia , Encefalite Infecciosa/microbiologia , Proteínas Serina-Treonina Quinases/metabolismo , Toxoplasma/metabolismo , Toxoplasmose/microbiologia , Síndrome da Imunodeficiência Adquirida/genética , Síndrome da Imunodeficiência Adquirida/metabolismo , Síndrome da Imunodeficiência Adquirida/patologia , Animais , Apoptose/fisiologia , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático , Feminino , HIV-1/isolamento & purificação , Interações Hospedeiro-Parasita , Encefalite Infecciosa/metabolismo , Encefalite Infecciosa/patologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas do Tecido Nervoso/metabolismo , Fosforilação , Proteínas de Protozoários , Toxoplasma/patogenicidade , Toxoplasmose/genética , Toxoplasmose/metabolismo , Toxoplasmose/patologia
14.
J Cell Sci ; 131(17)2018 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-30177506

RESUMO

Selective autophagy represents the major quality control mechanism that ensures proper turnover of exhausted or harmful organelles, among them the endoplasmic reticulum (ER), which is fragmented and delivered to the lysosome for degradation via a specific type of autophagy called ER-phagy. The recent discovery of ER-resident proteins that bind to mammalian Atg8 proteins has revealed that the selective elimination of ER involves different receptors that are specific for different ER subdomains or ER stresses. FAM134B (also known as RETREG1) and RTN3 are reticulon-type proteins that are able to remodel the ER network and ensure the basal membrane turnover. SEC62 and CCPG1 are transmembrane ER receptors that function in response to ER stress signals. This task sharing reflects the complexity of the ER in terms of biological functions and morphology. In this Cell Science at a Glance article and the accompanying poster, we summarize the most recent findings about ER-phagy in yeast and in mammalian cells.


Assuntos
Autofagia , Retículo Endoplasmático/metabolismo , Leveduras/metabolismo , Retículo Endoplasmático/genética , Estresse do Retículo Endoplasmático , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Lisossomos/metabolismo , Leveduras/citologia , Leveduras/genética
15.
FASEB J ; 33(1): 668-682, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30024789

RESUMO

Nogo-A is a key inhibitory molecule of axon regeneration in oligodendrocytes. However, little is known about its role in adult neurons. In this study, we showed an important function of Nogo-A on regulation of inflammatory pain in dorsal root ganglion (DRG) neurons. In adult rats with complete Freund's adjuvant (CFA) hind paw inflammation, DRG neurons showed a significant increase in Nogo-A expression. Disruption of Nogo-A signaling with Nogo-66 receptor antagonist peptide, Nogo-A blocking antibody, Nogo-A short hairpin RNA, or Nogo-A gene knockout attenuated CFA-induced inflammatory heat hyperalgesia. Moreover, disruption of Nogo-A signaling suppressed the function and expression in DRG neurons of the transient receptor potential vanilloid subfamily member (TRPV)-1 channel, which is known to be the endogenous transducer of noxious heat during inflammation. These effects were accompanied with a reduction in LIM domain kinase (LIMK)/cofilin phosphorylation and actin polymerization. Similar disruption of actin filament architecture by direct action of Latrunculin A reduced the TRPV-1 activity and up-regulation of TRPV-1 protein caused by CFA. We conclude that Nogo-A plays an essential role in the development of inflammatory heat hyperalgesia, partly through maintaining TRPV-1 function via activation of the LIMK/cofilin pathway, which regulates actin filament dynamics. These findings support a therapeutic potential of modulating Nogo-A signaling in pain management.-Hu, F., Liu, H.-C., Su, D.-Q., Chen, H.-J., Chan, S.-O., Wang, Y., Wang, J. Nogo-A promotes inflammatory heat hyperalgesia by maintaining TRPV-1 function in the rat dorsal root ganglion neuron.


Assuntos
Gânglios Espinais/patologia , Temperatura Alta/efeitos adversos , Hiperalgesia/etiologia , Inflamação Neurogênica/complicações , Neurônios/patologia , Proteínas Nogo/metabolismo , Canais de Cátion TRPV/metabolismo , Animais , Cofilina 1/metabolismo , Gânglios Espinais/imunologia , Gânglios Espinais/metabolismo , Hiperalgesia/metabolismo , Hiperalgesia/patologia , Quinases Lim/metabolismo , Masculino , Inflamação Neurogênica/metabolismo , Inflamação Neurogênica/patologia , Neurônios/imunologia , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley
16.
Virus Genes ; 56(6): 677-686, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32840739

RESUMO

We amplified a full-length hepatitis B virus (HBV) genome from the serum of a chronic hepatitis B patient who experienced virological breakthrough with high HBV DNA titer following adefovir (ADV) therapy. The PCR product was cloned and sequencing of the six clones revealed an isolate of C2 subgenotype. Mutation(s) in the polymerase gene responsible for ADV resistance included rtA181T (all clones) and rtN236T (four clones). The rtA181T mutation caused the W172* nonsense mutation in the overlapping S gene. In addition, all the clones harbored another nonsense mutation in the S gene (C69*) and a 207nt in-frame deletion in the preS1 region. These clones were converted to a 1.1mer construct for transient transfection of Huh7 cells. All the clones were deficient in hepatitis B surface antigen production. Three clones had similar levels of DNA replication. Comparison with a wild-type clone of the same genotype revealed a higher intracellular level of replicative DNA for clone c4, which was reduced by putting back the deleted 207nt, but not by co-transfection with an expression construct for the three surface proteins to rescue virion production. The HBcAg expression of the c4 and c4+207nt clones was mainly in the nucleus. Co-transfection with the L/M/S proteins expression construct did not alter the distribution of core. Clone c4 showed a significantly decreased susceptibility to ADV, a mild reduction in susceptibility to lamivudine and tenofovir, but remained sensitive to entecavir. In conclusion, this is an unusual ADV-resistant HBV isolate harboring two nonsense mutations in the S gene and a large in-frame deletion in the preS1 region, but still retains a high replication phenotype, which can provide a platform for recombinant vector construction.


Assuntos
Farmacorresistência Viral/genética , Genes Virais , Antígenos de Superfície da Hepatite B/genética , Hepatite B Crônica/virologia , Adenina/análogos & derivados , Adenina/uso terapêutico , Adulto , Antivirais/uso terapêutico , DNA Viral , Genótipo , Hepatite B Crônica/tratamento farmacológico , Humanos , Masculino , Mutação , Organofosfonatos/uso terapêutico
17.
J Physiol ; 597(7): 1919-1934, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30724347

RESUMO

KEY POINTS: Cholinergic projections from the pedunculopontine tegmental nucleus (PPTg) to the retrotrapezoid nucleus (RTN) are considered to be important for sleep-wake state-dependent control of breathing. The RTN also receives cholinergic input from the postinspiratory complex. Stimulation of the PPTg increases respiratory output under control conditions but not when muscarinic receptors in the RTN are blocked. The data obtained in the present study support the possibility that arousal-dependent modulation of breathing involves recruitment of cholinergic projections from the PPTg to the RTN. ABSTRACT: The pedunculopontine tegmental nucleus (PPTg) in the mesopontine region has important physiological functions, including breathing control. The PPTg contains a variety of cell types, including cholinergic neurons that project to the rostral aspect of the ventrolateral medulla. In addition, cholinergic signalling in the retrotrapezoid nucleus (RTN), a region that contains neurons that regulate breathing in response to changes in CO2 /H+ , has been shown to activate chemosensitive neurons and increase inspiratory activity. The present study aimed to identify the source of cholinergic input to the RTN and determine whether cholinergic signalling in this region influences baseline breathing or the ventilatory response to CO2 in conscious male Wistar rats. Retrograde tracer Fluoro-Gold injected into the RTN labelled a subset of cholinergic PPTg neurons that presumably project directly to the chemosensitive region of the RTN. In unrestrained awake rats, unilateral injection of the glutamate (10 mm/100 nL) in the PPTg decreased tidal volume (VT ) but otherwise increased respiratory rate (fR ) and net respiratory output as indicated by an increase in ventilation (VE ). All respiratory responses elicited by PPTg stimulation were blunted by prior injection of methyl-atropine (5 mm/50-75 nL) into the RTN. These results show that stimulation of the PPTg can increase respiratory activity in part by cholinergic activation of chemosensitive elements of the RTN. Based on previous evidence that cholinergic PPTg projections may simultaneously activate expiratory output from the pFRG, we speculate that cholinergic signalling at the level of RTN region could also be involved in breathing regulation.


Assuntos
Neurônios Colinérgicos/fisiologia , Núcleo Tegmental Pedunculopontino/fisiologia , Animais , Derivados da Atropina/farmacologia , Pressão Sanguínea , Fenômenos Eletrofisiológicos , Ácido Glutâmico/farmacologia , Ácido Cinurênico/farmacologia , Masculino , Ratos , Ratos Wistar , Receptor Muscarínico M1/metabolismo , Fenômenos Fisiológicos Respiratórios
18.
Circulation ; 138(17): 1828-1838, 2018 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-29716941

RESUMO

BACKGROUND: Reticulon 3 (RTN3) is an endoplasmic reticulum protein that has previously been shown to play a role in neurodegenerative diseases, but little is known about its role in lipid metabolism. METHODS: Obese patients (n=149), hypertriglyceridemic patients (n=343), and healthy control subjects (n=84) were enrolled to assess their levels of RTN3. To explore the pathophysiological roles of RTN3 in the control of lipid metabolism, we used transgenic mice overexpressing the wild-type human RTN3 gene, the RTN3-null transgenic mouse model, and multiple Caenorhabditis legans strains for molecular characterization. The underlying mechanisms were studied with 3T3L1 cell cultures in vitro. RESULTS: We report that overexpressed RTN3 in mice induces obesity and higher accumulation of triglycerides. Increased RTN3 expression is also found in patients with obesity and hypertriglyceridemia. We reveal that RTN3 plays critical roles in regulating the biosynthesis and storage of triglycerides and in controlling lipid droplet expansion. Mechanistically, RTN3 regulates these events through its interactions with heat shock protein family A (Hsp70) member 5, and this enhanced interaction increases sterol regulatory element-binding protein 1c and AMP-activated kinase activity. CONCLUSIONS: This study provides evidence for a role of RTN3 in inducing obesity and triglyceride accumulation and suggests that inhibiting the expression of RTN3 in fat tissue may be a novel therapeutic approach to treat obesity and hypertriglyceridemia.


Assuntos
Tecido Adiposo/metabolismo , Proteínas de Transporte/sangue , Proteínas de Choque Térmico/metabolismo , Hipertrigliceridemia/sangue , Proteínas de Membrana/sangue , Proteínas do Tecido Nervoso/sangue , Proteínas do Tecido Nervoso/metabolismo , Obesidade/sangue , Triglicerídeos/sangue , Células 3T3-L1 , Proteínas Quinases Ativadas por AMP , Adolescente , Adulto , Animais , Biomarcadores/sangue , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Transporte/genética , Estudos de Casos e Controles , Chaperona BiP do Retículo Endoplasmático , Feminino , Predisposição Genética para Doença , Proteínas de Choque Térmico/genética , Humanos , Hipertrigliceridemia/diagnóstico , Hipertrigliceridemia/genética , Gotículas Lipídicas/metabolismo , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Obesidade/diagnóstico , Obesidade/genética , Fenótipo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Regulação para Cima , Adulto Jovem
19.
Sensors (Basel) ; 19(24)2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31835566

RESUMO

In this paper we present a systematic approach to sort out different types of random telegraph noises (RTN) in CMOS image sensors (CIS) by examining their dependencies on the transfer gate off-voltage, the reset gate off-voltage, the photodiode integration time, and the sense node charge retention time. Besides the well-known source follower RTN, we have identified the RTN caused by varying photodiode dark current, transfer-gate and reset-gate induced sense node leakage. These four types of RTN and the dark signal shot noises dominate the noise distribution tails of CIS and non-CIS chips under test, either with or without X-ray irradiation. The effect of correlated multiple sampling (CMS) on noise reduction is studied and a theoretical model is developed to account for the measurement results.

20.
J Pak Med Assoc ; 69(10): 1425-1430, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31622291

RESUMO

OBJECTIVES: To find interactions of the ligand with axonali nhibitors, and to check the optimum interactions of existing drugs as inhibitors for the protein that hinders the growth of injured neurons. METHODS: The study was conducted at Kongju National University, Korea from May 2016 to March 2017. It consisted of two parts. Molecular analysis and bioinformatics analysis. The study comprised a family of six with Charcot-Marie-Tooth phenotypes, recommended by a neurologist for molecular analysis on the clinical symptoms to find the mutations responsible for the disease. Blood samples were collected from each family member and total deoxyribonucleic acid was extracted and it was analysed for Reticulon 4 gene by sequencing the coding and intronic regions. However, a missense mutation was found on exon 2 of the gene in the proband and the whole family was subsequently analysed. Bioinformatics analysis and docking studies were carried out to investigate the potential behaviour of Reticulon 4 as therapeutic agent. Sequencing analysis was performed to find the pathoegenic variant responsible for Charcot-Marie-Tooth type 1. RESULTS: After checking pathogenicity of the mutation, Reticulon 4 gene was found to be not involved in Charcot- Marie-Tooth disease type 1. CONCLUSIONS: Reticulon 4 gene was not found to be involved in causing Charcot-Marie-Tooth disease type 1.


Assuntos
Axônios/metabolismo , Doença de Charcot-Marie-Tooth/genética , Proteínas Nogo/genética , Remielinização/genética , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/análogos & derivados , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/metabolismo , Adulto , Pré-Escolar , Simulação por Computador , Família , Feminino , Proteínas Ligadas por GPI/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Simulação de Acoplamento Molecular , Terapia de Alvo Molecular , Mutação de Sentido Incorreto , Proteínas da Mielina/metabolismo , Glicoproteína Associada a Mielina/metabolismo , Regeneração Nervosa/genética , Proteínas Nogo/metabolismo , Linhagem , Inibidores de Proteínas Quinases/metabolismo
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