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1.
Cell Adh Migr ; 18(1): 1-11, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38357988

RESUMO

The intensive study and investigation of neuroprotective therapy for central nervous system (CNS) diseases is ongoing. Due to shared mechanisms of neurodegeneration, a neuroprotective approach might offer benefits across multiple neurological disorders, despite variations in symptoms or injuries. C-Jun N-terminal Kinase 3 (JNK3) is found primarily in the CNS and is involved in physiological processes such as brain development, synapse formation, and memory formation. The potential of JNK3 as a target for pharmacological development holds promise for advancing neuroprotective therapies. Developing small molecule JNK3 inhibitors into drugs with neuroprotective qualities could facilitate neuronal restoration and self-repair. This review focuses on elucidating key neuroprotective mechanisms, exploring the interplay between neurodegenerative diseases and neuroprotection, and discussing advancements in JNK3 inhibitor drug development.


Assuntos
Proteína Quinase 10 Ativada por Mitógeno , Neuroproteção , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Inibidores de Proteínas Quinases/farmacologia
2.
Front Immunol ; 12: 767813, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34858424

RESUMO

Viral infections seriously affect the health of organisms including humans. Now, more and more researchers believe that microRNAs (miRNAs), one of the members of the non-coding RNA family, play significant roles in cell biological function, disease occurrence, and immunotherapy. However, the roles of miRNAs in virus infection (entry and replication) and cellular immune response remain poorly understood, especially in low vertebrate fish. In this study, based on the established virus-cell infection model, Singapore grouper iridovirus (SGIV)-infected cells were used to explore the roles of miR-124 of Epinephelus coioides, an economically mariculture fish in southern China and Southeast Asia, in viral infection and host immune responses. The expression level of E. coioides miR-124 was significantly upregulated after SGIV infection; miR-124 cannot significantly affect the entry of SGIV, but the upregulated miR-124 could significantly promote the SGIV-induced cytopathic effects (CPEs), the viral titer, and the expressions of viral genes. The target genes of miR-124 were JNK3/p38α mitogen-activated protein kinase (MAPK). Overexpression of miR-124 could dramatically inhibit the activation of NF-κB/activating protein-1 (AP-1), the transcription of proinflammatory factors, caspase-9/3, and the cell apoptosis. And opposite results happen when the expression of miR-124 was inhibited. The results suggest that E. coioides miR-124 could promote viral replication and negatively regulate host immune response by targeting JNK3/p38α MAPK, which furthers our understanding of virus and host immune interactions.


Assuntos
Bass/virologia , Infecções por Vírus de DNA/veterinária , Doenças dos Peixes/imunologia , Iridovirus/fisiologia , MicroRNAs/fisiologia , Replicação Viral , Animais , Apoptose , Infecções por Vírus de DNA/imunologia , Imunidade Inata , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologia
3.
Apoptosis ; 22(3): 449-462, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27864650

RESUMO

The mechanisms by which oxidative stress induces spinal cord neuron death has not been completely understood. Investigation on the molecular signal pathways involved in oxidative stress-mediated neuronal death is important for development of new therapeutics for oxidative stress-associated spinal cord disorders. In current study we examined the role of heme oxygenase-1 (HO-1) in the modulation of MLK3/MKK7/JNK3 signaling, which is a pro-apoptotic pathway, after treating primary spinal cord neurons with H2O2. We found that MLK3/MKK7/JNK3 signaling was substantially activated by H2O2 in a time-dependent manner, demonstrated by increase of activating phosphorylation of MLK3, MKK7 and JNK3. H2O2 also induced expression of HO-1. Transduction of neurons with HO-1-expressing adeno-associated virus before H2O2 treatment introduced expression of exogenous HO-1 in neurons. Exogenous HO-1 reduced phosphorylation of MLK3, MKK7 and JNK3. Consistent with its inhibitory effect on MLK3/MKK7/JNK3 signaling, exogenous HO-1 decreased H2O2-induced neuronal apoptosis and necrosis. Furthermore, we found that exogenous HO-1 inhibited expression of Cdc42, which is crucial for MLK3 activation. In addition, HO-1-induced down-regulation of MLK3/MKK7/JNK3 signaling might be related to up-regulation of microRNA-137 (mir-137). A mir-137 inhibitor alleviated the inhibitory effect of HO-1 on JNK3 activation. This inhibitor also increased neuronal death even when exogenous HO-1 was expressed. Therefore, our study suggests a novel mechanism by which HO-1 exerted its neuroprotective efficacy on oxidative stress.


Assuntos
Apoptose/efeitos dos fármacos , Heme Oxigenase (Desciclizante)/fisiologia , Peróxido de Hidrogênio/antagonistas & inibidores , MAP Quinase Quinase 7/fisiologia , MAP Quinase Quinase Quinases/fisiologia , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Neurônios/patologia , Transdução de Sinais/efeitos dos fármacos , Medula Espinal/citologia , Proteína cdc42 de Ligação ao GTP/fisiologia , Animais , Apoptose/fisiologia , Células Cultivadas , Indução Enzimática , Heme Oxigenase (Desciclizante)/genética , Peróxido de Hidrogênio/farmacologia , MicroRNAs/biossíntese , MicroRNAs/genética , MicroRNAs/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Fosforilação , Cultura Primária de Células , Processamento de Proteína Pós-Traducional , Ratos , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais/fisiologia , Transdução Genética , Proteína cdc42 de Ligação ao GTP/biossíntese , Proteína cdc42 de Ligação ao GTP/genética , MAP Quinase Quinase Quinase 11 Ativada por Mitógeno
4.
Neurobiol Aging ; 48: 103-113, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27644079

RESUMO

Nuclear spheres are protein aggregates consisting of FE65, TIP60, BLM, and other yet unknown proteins. Generation of these structures in the cellular nucleus is putatively modulated by the amyloid precursor protein (APP), either by its cleavage or its phosphorylation. Nuclear spheres were preferentially studied in cell culture models and their existence in the human brain had not been known. Existence of nuclear spheres in the human brain was studied using immunohistochemistry. Cell culture experiments were used to study regulative mechanisms of nuclear sphere generation. The comparison of human frontal cortex brain samples from Alzheimer's disease (AD) patients to age-matched controls revealed a dramatically and highly significant enrichment of nuclear spheres in the AD brain. Costaining demonstrated that neurons are distinctly affected by nuclear spheres, but astrocytes never are. Nuclear spheres were predominantly found in neurons that were negative for threonine 668 residue in APP phosphorylation. Cell culture experiments revealed that JNK3-mediated APP phosphorylation reduces the amount of sphere-positive cells. The study suggests that nuclear spheres are a new APP-derived central hallmark of AD, which might be of crucial relevance for the molecular mechanisms in neurodegeneration.


Assuntos
Doença de Alzheimer/etiologia , Doença de Alzheimer/metabolismo , Encéfalo/citologia , Encéfalo/metabolismo , Núcleo Celular/metabolismo , Histona Acetiltransferases/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/metabolismo , Agregados Proteicos , RecQ Helicases/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/fisiologia , Células HEK293 , Humanos , Lisina Acetiltransferase 5 , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Neurônios/citologia , Neurônios/metabolismo , Fosforilação
5.
Arterioscler Thromb Vasc Biol ; 34(9): 2023-32, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24990230

RESUMO

OBJECTIVE: Reactive oxygen species (ROS) act as signaling molecules during angiogenesis; however, the mechanisms used for such signaling events remain unclear. Stromal cell-derived factor-1α (SDF-1α) is one of the most potent angiogenic chemokines. Here, we examined the role of ROS in the regulation of SDF-1α-dependent angiogenesis. APPROACH AND RESULTS: Bovine aortic endothelial cells were treated with SDF-1α, and intracellular ROS generation was monitored. SDF-1α treatment induced bovine aortic endothelial cell migration and ROS generation, with the majority of ROS generated by bovine aortic endothelial cells at the leading edge of the migratory cells. Antioxidants and nicotinamide adenine dinucleotide phosphate oxidase (NOX) inhibitors blocked SDF-1α-induced endothelial migration. Furthermore, knockdown of either NOX5 or p22phox (a requisite subunit for NOX1/2/4 activation) significantly impaired endothelial motility and tube formation, suggesting that multiple NOXs regulate SDF-1α-dependent angiogenesis. Our previous study demonstrated that c-Jun N-terminal kinase 3 activity is essential for SDF-1α-dependent angiogenesis. Here, we identified that NOX5 is the dominant NOX required for SDF-1α-induced c-Jun N-terminal kinase 3 activation and that NOX5 and MAP kinase phosphatase 7 (MKP7; the c-Jun N-terminal kinase 3 phosphatase) associate with one another but decrease this interaction on SDF-1α treatment. Furthermore, MKP7 activity was inhibited by SDF-1α, and this inhibition was relieved by NOX5 knockdown, indicating that NOX5 promotes c-Jun N-terminal kinase 3 activation by blocking MKP7 activity. CONCLUSIONS: We conclude that NOX is required for SDF-1α signaling and that intracellular redox balance is critical for SDF-1α-induced endothelial migration and angiogenesis.


Assuntos
Quimiocina CXCL12/fisiologia , Proteínas de Membrana/fisiologia , NADPH Oxidases/fisiologia , Neovascularização Fisiológica/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Acetilcisteína/farmacologia , Animais , Antioxidantes/farmacologia , Aorta , Azóis/farmacologia , Bovinos , Movimento Celular/efeitos dos fármacos , Quimiocina CXCL12/farmacologia , Fosfatases de Especificidade Dupla/fisiologia , Células Endoteliais/efeitos dos fármacos , Endotélio Vascular/citologia , Técnicas de Silenciamento de Genes , Hiperglicemia/metabolismo , Isoenzimas/antagonistas & inibidores , Isoenzimas/genética , Isoenzimas/fisiologia , Isoindóis , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Fosfatases da Proteína Quinase Ativada por Mitógeno/fisiologia , NADPH Oxidases/antagonistas & inibidores , NADPH Oxidases/genética , Neovascularização Fisiológica/efeitos dos fármacos , Compostos Organosselênicos/farmacologia , Oxirredução , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
6.
Behav Brain Res ; 245: 88-95, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23428746

RESUMO

c-Jun N-terminal kinases (JNKs) are central and ubiquitous mediators of cellular signaling for both physiogical-regenerative and pathological-apoptotic processes. Their impact on degeneration or inflammation is well documented, but so far little is known about their roles in higher brain functions. The more, the contribution of individual JNK isoforms remains obscure so far. Here we have tested the behaviour of JNK1, JNK2 and JNK3 knockout (ko) mice in elevated plus maze (EPM), open field (OF), novel object recognition memory (NORM) test and Morris water maze (MWM). Compared with wild type C57BL/6N mice JNK ko mice revealed significant differences. Taken together the data on anxiety, exploration and learning indicate that JNK1 ko mice displayed a stronger explorative behaviour and that knockout of JNK2 or JNK3 showed a tendency of behaviour opposite to that of JNK1 ko mice. This pattern reminds of the impact of individual JNK ko on neurodegeneration. This is the first comparative study on the impact of individual JNK ko on behavioural parameters.


Assuntos
Comportamento Animal/fisiologia , Proteína Quinase 10 Ativada por Mitógeno/genética , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Proteína Quinase 8 Ativada por Mitógeno/genética , Proteína Quinase 8 Ativada por Mitógeno/fisiologia , Proteína Quinase 9 Ativada por Mitógeno/genética , Proteína Quinase 9 Ativada por Mitógeno/fisiologia , Animais , Ansiedade/psicologia , Western Blotting , Peso Corporal/fisiologia , Encéfalo/enzimologia , Comportamento Exploratório/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Atividade Motora/fisiologia , Reconhecimento Psicológico/fisiologia
7.
J Neurol Sci ; 317(1-2): 123-9, 2012 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-22386689

RESUMO

Although recent researches show that Heat Shock Protein 72 (HSP72) plays an important role in neuronal survival, little knowledge is known about the precise mechanisms during cerebral ischemia/reperfusion (I/R). Our present study investigated the neuroprotective mechanisms of HSP72 against ischemic brain injury induced by cerebral I/R. Mild heat shock pretreatment was employed to induce the overexpression of HSP72 by immersing rats into the water bath at 42°C for 20 min before cerebral I/R. HSP72 antisense oligodeoxynucleotides (ODNs) were used to inhibit HSP72 expression by intracerebroventricular infusion once per day for 3 days before cerebral I/R animal model was induced by four-vessel occlusion for 15 min transient ischemia and then reperfused for various time in Sprague-Dawley rats. Immunoprecipitation and immunoblotting were used to detect the expression of the related proteins. HE-staining and TUNEL-staining were carried out to examine the neuronal death of hippocampal CA1 region. Results showed that mild heat shock could increase the phosphorylation of protein kinase B (Akt), inhibit the assembly of MLK3-MKK7-JNK3 signaling module, diminish the phosphorylation of JNK3 and c-Jun, and decrease the activation of caspase-3. Furthermore, mild heat shock could significantly protect neurons against cerebral I/R. Whereas, all of the aforementioned effects of mild heat shock were reversed by HSP72 antisense ODNs. In summary, our results imply that Akt1 activation is involved in the neuroprotection of HSP72 against ischemic brain injury via suppressing JNK3 signaling pathway and provide a new experimental foundation for stroke therapy.


Assuntos
Isquemia Encefálica/metabolismo , Proteínas de Choque Térmico HSP72/fisiologia , Sistema de Sinalização das MAP Quinases/genética , Proteína Quinase 10 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Animais , Isquemia Encefálica/prevenção & controle , Proteínas de Choque Térmico HSP72/biossíntese , Infusões Intraventriculares , Masculino , Oligonucleotídeos Antissenso/administração & dosagem , Ratos , Ratos Sprague-Dawley
8.
J Neurochem ; 121(4): 607-18, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22372722

RESUMO

Although neural c-Jun is essential for successful peripheral nerve regeneration, the cellular basis of this effect and the impact of c-Jun activation are incompletely understood. In the current study, we explored the effects of neuron-selective c-Jun deletion, substitution of serine 63 and 73 phosphoacceptor sites with non-phosphorylatable alanine, and deletion of Jun N-terminal kinases 1, 2 and 3 in mouse facial nerve regeneration. Removal of the floxed c-jun gene in facial motoneurons using cre recombinase under control of a neuron-specific synapsin promoter (junΔS) abolished basal and injury-induced neuronal c-Jun immunoreactivity, as well as most of the molecular responses following facial axotomy. Absence of neuronal Jun reduced the speed of axonal regeneration following crush, and prevented most cut axons from reconnecting to their target, significantly reducing functional recovery. Despite blocking cell death, this was associated with a large number of shrunken neurons. Finally, junΔS mutants also had diminished astrocyte and microglial activation and T-cell influx, suggesting that these non-neuronal responses depend on the release of Jun-dependent signals from neighboring injured motoneurons. The effects of substituting serine 63 and 73 phosphoacceptor sites (junAA), or of global deletion of individual kinases responsible for N-terminal c-Jun phosphorylation were mild. junAA mutants showed decrease in neuronal cell size, a moderate reduction in post-axotomy CD44 levels and slightly increased astrogliosis. Deletion of Jun N-terminal kinase (JNK)1 or JNK3 showed delayed functional recovery; deletion of JNK3 also interfered with T-cell influx, and reduced CD44 levels. Deletion of JNK2 had no effect. Thus, neuronal c-Jun is needed in regeneration, but JNK phosphorylation of the N-terminus mostly appears to not be required for its function.


Assuntos
Axônios/fisiologia , Regeneração Nervosa/fisiologia , Neurônios/fisiologia , Proteínas Proto-Oncogênicas c-jun/fisiologia , Animais , Atrofia , Axônios/ultraestrutura , Morte Celular , Feminino , Receptores de Hialuronatos/metabolismo , Masculino , Camundongos , Camundongos Knockout , Proteína Quinase 10 Ativada por Mitógeno/genética , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Proteína Quinase 8 Ativada por Mitógeno/genética , Proteína Quinase 8 Ativada por Mitógeno/fisiologia , Proteína Quinase 9 Ativada por Mitógeno/genética , Proteína Quinase 9 Ativada por Mitógeno/fisiologia , Neurônios Motores/fisiologia , Regeneração Nervosa/genética , Neurônios/ultraestrutura , Fosforilação , Mutação Puntual/fisiologia , Proteínas Proto-Oncogênicas c-jun/genética
9.
Neurobiol Dis ; 46(2): 393-401, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22353563

RESUMO

Glaucoma is a neurodegenerative disease characterized by the apoptotic death of retinal ganglion cells (RGCs). The primary insult to RGCs in glaucoma is thought to occur to their axons as they exit the eye in the optic nerve head. However, pathological signaling pathways that exert central roles in triggering RGC death following axonal injury remain unidentified. It is likely that the first changes to occur following axonal injury are signal relay events that transduce the injury signal from the axon to the cell body. Here we focus on the c-Jun N-terminal kinase (JNK1-3) family, a signaling pathway implicated in axonal injury signaling and neurodegenerative apoptosis, and likely to function as a central node in axonal injury-induced RGC death. We show that JNK signaling is activated immediately after axonal injury in RGC axons at the site of injury. Following its early activation, sustained JNK signaling is observed in axonally-injured RGCs in the form of JUN phosphorylation and upregulation. Using mice lacking specific Jnk isoforms, we show that Jnk2 and Jnk3 are the isoforms activated in injured axons. Combined deficiency of Jnk2 and Jnk3 provides robust long-term protection against axonal injury-induced RGC death and prevents downregulation of the RGC marker, BRN3B, and phosphorylation of JUN. Finally, using Jun deficient mice, we show that JUN-dependent pathways are important for axonal injury-induced RGC death. Together these data demonstrate that JNK signaling is the major early pathway triggering RGC death after axonal injury and may directly link axon injury to transcriptional activity that controls RGC death.


Assuntos
Axônios/enzimologia , Sistema de Sinalização das MAP Quinases/fisiologia , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Proteína Quinase 9 Ativada por Mitógeno/fisiologia , Células Ganglionares da Retina/enzimologia , Animais , Axônios/patologia , Morte Celular , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Traumatismos do Nervo Óptico/enzimologia , Traumatismos do Nervo Óptico/genética , Traumatismos do Nervo Óptico/patologia , Células Ganglionares da Retina/patologia , Ativação Transcricional/fisiologia
10.
Biochemistry ; 50(48): 10520-9, 2011 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-22047447

RESUMO

Arrestins make up a small family of proteins with four mammalian members that play key roles in the regulation of multiple G protein-coupled receptor-dependent and -independent signaling pathways. Although arrestins were reported to serve as scaffolds for MAP kinase cascades, promoting the activation of JNK3, ERK1/2, and p38, the molecular mechanisms involved were not elucidated, and even the direct binding of arrestins with MAP kinases was never demonstrated. Here, using purified proteins, we show that both nonvisual arrestins directly bind JNK3α2 and its upstream activator MKK4, and that the affinity of arrestin-3 for these kinases is higher than that of arrestin-2. Reconstitution of the MKK4-JNK3α2 signaling module from pure proteins in the presence of different arrestin-3 concentrations showed that arrestin-3 acts as a "true" scaffold, facilitating JNK3α2 phosphorylation by bringing the two kinases together. Both the level of JNK3α2 phosphorylation by MKK4 and JNK3α2 activity toward its substrate ATF2 increase at low and then decrease at high arrestin-3 levels, yielding a bell-shaped concentration dependence expected with true scaffolds that do not activate the upstream kinase or its substrate. Thus, direct binding of both kinases and true scaffolding is the molecular mechanism of action of arrestin-3 on the MKK4-JNK3α2 signaling module.


Assuntos
Arrestinas/fisiologia , MAP Quinase Quinase 4/fisiologia , Sistema de Sinalização das MAP Quinases/fisiologia , Proteína Quinase 10 Ativada por Mitógeno/metabolismo , Animais , Arrestinas/metabolismo , Bovinos , Células Cultivadas , Humanos , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase 4/metabolismo , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Fosforilação/fisiologia , Ligação Proteica/fisiologia , Regulação para Cima/fisiologia , beta-Arrestinas
11.
J Alzheimers Dis ; 24(4): 633-42, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21321401

RESUMO

c-Jun N-terminal kinases (JNKs) and in particular JNK3 the neuronal specific isoform, have been recognized as important enzymes in the pathology of diverse neurological disorders. Indeed, several efforts have been made to design drugs that inhibit JNK signaling. The success that characterized the new generation of cell permeable peptides raise the hope in the field of neurodegeneration for new therapeutic routes. However, in order to design new and more efficient therapeutical approaches careful re-examination of current knowledge is required. Scaffold proteins are key endogenous regulators of JNK signaling: they can modulate spatial and temporal activation of the JNK signaling and can thus provide the basis for the design of more specific inhibitors. This review focuses on delineating the role of scaffold proteins on the regulation of JNK signaling in neurons. Furthermore the possibility to design a new JNK3 cell permeable peptide inhibitor by targeting the ß-arrestin-JNK3 interaction is discussed.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Proteína Quinase 10 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 10 Ativada por Mitógeno/metabolismo , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/enzimologia , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/uso terapêutico , Animais , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Doenças Neurodegenerativas/patologia , Neurônios/enzimologia , Neurônios/patologia , Proteínas Associadas à Matriz Nuclear/fisiologia
12.
Exp Eye Res ; 92(4): 299-305, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21272576

RESUMO

To determine if the absence of c-Jun N-terminal kinase 3 (JNK3) in the mouse retina would reduce retinal ganglion cell (RGC) loss in mice with experimental glaucoma. C57BL/6 mice underwent experimental intraocular pressure (IOP) elevation with a bead/viscoelastic injection into one eye. One-half of the mice were Jnk3 homozygous knockouts (KO) and were compared to wild type (WT) mice. IOP was measured under anesthesia with the TonoLab, axial length was measured post-mortem with calipers after inflation to 15mmHg, and RGC layer counts were performed on retinal whole mount images stained with DAPI, imaged by confocal microscopy, and counted by masked observers in an image analysis system. Axon counts were performed in optic nerve cross-sections by semi-automated image analysis. Both WT and Jnk3(-/-) mice had mean elevations of IOP of more than 50% after bead injection. Both groups underwent the expected axial globe elongation due to chronic IOP elevation. The absence of JNK3 in KO retina was demonstrated by Western blots. RGC layer neuron counts showed modest loss in both WT and Jnk3(-/-) animals; local differences by retinal eccentricity were detected, in each case indicating greater loss in KO animals than in WT. The baseline number of RGC layer cells in KO animals was 10% higher than in WT, but the number of optic nerve axons was identical in KO and WT controls. A slightly greater loss of RGC in Jnk3(-/-) mice compared to controls was detected in experimental mouse glaucoma by RGC layer counting and there was no protective effect shown in axon counts. Counts of RGC layer cells and optic nerve axons indicate that Jnk3(-/-) mice have an increased number of amacrine cells compared to WT controls.


Assuntos
Axônios/patologia , Modelos Animais de Doenças , Glaucoma/metabolismo , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Doenças do Nervo Óptico/metabolismo , Células Ganglionares da Retina/patologia , Células Amácrinas/patologia , Animais , Comprimento Axial do Olho , Western Blotting , Contagem de Células , Citoproteção , Glaucoma/patologia , Glaucoma/prevenção & controle , Pressão Intraocular , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Confocal , Hipertensão Ocular/patologia , Doenças do Nervo Óptico/patologia , Doenças do Nervo Óptico/prevenção & controle , Retina/metabolismo , Sinucleínas/metabolismo , Tonometria Ocular
13.
J Neurosci ; 30(40): 13348-61, 2010 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-20926661

RESUMO

In the adult mouse, signaling through c-Jun N-terminal kinases (JNKs) links exposure to acute stress to various physiological responses. Inflammatory cytokines, brain injury and ischemic insult, or exposure to psychological acute stressors induce activation of hippocampal JNKs. Here we report that exposure to acute stress caused activation of JNKs in the hippocampal CA1 and CA3 subfields, and impaired contextual fear conditioning. Conversely, intrahippocampal injection of JNKs inhibitors sp600125 (30 µm) or D-JNKI1 (8 µm) reduced activity of hippocampal JNKs and rescued stress-induced deficits in contextual fear. In addition, intrahippocampal administration of anisomycin (100 µg/µl), a potent JNKs activator, mimicked memory-impairing effects of stress on contextual fear. This anisomycin-induced amnesia was abolished after cotreatment with JNKs selective inhibitor sp600125 without affecting anisomycin's ability to effectively inhibit protein synthesis as measured by c-Fos immunoreactivity. We also demonstrated milder and transient activation of the JNKs pathway in the CA1 subfield of the hippocampus during contextual fear conditioning and an enhancement of contextual fear after pharmacological inhibition of JNKs under baseline conditions. Finally, using combined biochemical and transgenic approaches with mutant mice lacking different members of the JNK family (Jnk1, Jnk2, and Jnk3), we provided evidence that JNK2 and JNK3 are critically involved in stress-induced deficit of contextual fear, while JNK1 mainly regulates baseline learning in this behavioral task. Together, these results support the possibility that hippocampal JNKs serve as a critical molecular regulator in the formation of contextual fear.


Assuntos
Aprendizagem por Associação/fisiologia , Regulação para Baixo/fisiologia , Hipocampo/enzimologia , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Proteína Quinase 8 Ativada por Mitógeno/fisiologia , Proteína Quinase 9 Ativada por Mitógeno/fisiologia , Neurônios/enzimologia , Estresse Psicológico/enzimologia , Sequência de Aminoácidos , Amnésia/induzido quimicamente , Amnésia/enzimologia , Amnésia/prevenção & controle , Animais , Anisomicina/farmacologia , Aprendizagem da Esquiva/fisiologia , Região CA1 Hipocampal/citologia , Região CA1 Hipocampal/enzimologia , Região CA3 Hipocampal/citologia , Região CA3 Hipocampal/enzimologia , Regulação para Baixo/genética , Feminino , Hipocampo/citologia , Isoenzimas/antagonistas & inibidores , Isoenzimas/deficiência , Isoenzimas/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína Quinase 10 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 10 Ativada por Mitógeno/deficiência , Proteína Quinase 8 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 8 Ativada por Mitógeno/deficiência , Proteína Quinase 9 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 9 Ativada por Mitógeno/deficiência , Dados de Sequência Molecular , Inibidores de Proteínas Quinases/farmacologia , Estresse Psicológico/genética , Estresse Psicológico/fisiopatologia
14.
Neurochem Int ; 54(7): 418-25, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19428783

RESUMO

Increasing evidence suggests that c-Jun N-terminal kinase (JNK) is an important kinase mediating neuronal death in Parkinson's disease (PD) model induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). JNK3, the only neural-specific isoform, may play an important role in mediating the neurotoxic effects of MPTP in dopaminergic neuronal injury. To analyze the variation in JNK3 activation, the levels of phospho-JNK3 were measured at the various time points of occurrence of MPTP-induced lesions. In our study, we observed that during MPTP intoxication, two peaks of JNK3 activation appeared at 8 and 24h. To further define the mechanism of JNK3 activation and translocation, the antioxidant N-acetylcysteine (NAC), the N-methyl-D-aspartate (NMDA) receptor antagonist ketamine, and the alpha-amino-3-hydroxyl-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate (KA) receptor antagonist 6,7-dinitroquinoxaline-2,3(1H,4H)-dione (DNQX) were administered to the mice 30 min after each of the four MPTP injections. The results revealed that NAC clearly inhibited JNK3 activation during the early intoxication, whereas ketamine preferably attenuated JNK3 activation during the latter intoxication. DNQX had no significant effects on JNK3 activation during intoxication. Consequently, reactive oxygen species (ROS) and the NMDA receptor were closely associated with JNK3 activation following MPTP intoxication. NAC and ketamine exerted a preventive effect against MPTP-induced loss of tyrosine hydroxylase-positive neurons and suppressed the nuclear translocation of JNK3, suggesting that NAC and ketamine can prevent MPTP-induced dopaminergic neuronal death by suppressing JNK3 activation.


Assuntos
Dopamina/fisiologia , Proteína Quinase 10 Ativada por Mitógeno/antagonistas & inibidores , Neurônios/patologia , Doença de Parkinson/patologia , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologia , Acetilcisteína/farmacologia , Animais , Western Blotting , Núcleo Celular/metabolismo , Dopaminérgicos/farmacologia , Ativação Enzimática/efeitos dos fármacos , Antagonistas de Aminoácidos Excitatórios/farmacologia , Imuno-Histoquímica , Imunoprecipitação , Ketamina/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Neostriado/patologia , Transporte Proteico/efeitos dos fármacos , Quinoxalinas/farmacologia , Tirosina 3-Mono-Oxigenase/metabolismo
15.
Mol Cancer Ther ; 7(2): 314-29, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18281516

RESUMO

The present studies defined the biological effects of a GST fusion protein of melanoma differentiation-associated gene-7 (mda-7), GST-MDA-7 (1 and 30 nmol/L), on cell survival and cell signaling in primary human glioma cells in vitro. GST-MDA-7, in a dose- and time-dependent fashion killed glioma cells with diverse genetic characteristics; 1 nmol/L caused arrest without death, whereas 30 nmol/L caused arrest and killing after exposure. Combined inhibition of extracellular signal-regulated kinase 1/2 (ERK1/2) and AKT function was required to enhance 1 nmol/L GST-MDA-7 lethality in all cell types, whereas combined activation of MEK1 and AKT was required to suppress 30 nmol/L GST-MDA-7 lethality; both effects are mediated in part by modulating c-Jun NH(2)-terminal kinase (JNK) 1-3 activity. The geldanamycin 17AAG inhibited AKT and ERK1/2 in GBM cells and enhanced GST-MDA-7 lethality. JNK1-3 signaling promoted BAX activation and mitochondrial dysfunction. In GBM6 cells, GST-MDA-7 (30 nmol/L) transiently activated p38 mitogen-activated protein kinase, which was modestly protective against JNK1-3-induced toxicity, whereas GST-MDA-7 (300 nmol/L) caused prolonged intense p38 mitogen-activated protein kinase activation, which promoted cell death. In GBM12 cells that express full-length mutant activated ERBB1, inhibition of ERBB1 did not modify GST-MDA-7 lethality; however, in U118 established glioma cells, stable overexpression of wild-type ERBB1 and/or truncated active ERBB1vIII suppressed GST-MDA-7 lethality. Our data argue that combined inhibition of ERK1/2 and AKT function, regardless of genetic background, promotes MDA-7 lethality in human primary human glioma cells via JNK1-3 signaling and is likely to represent a more ubiquitous approach to enhancing MDA-7 toxicity in this cell type than inhibition of ERBB1 function.


Assuntos
Apoptose/genética , Receptores ErbB/fisiologia , Glioblastoma/patologia , Interleucinas/genética , Proteínas Quinases JNK Ativadas por Mitógeno/fisiologia , Proteína Quinase 1 Ativada por Mitógeno/fisiologia , Proteína Quinase 3 Ativada por Mitógeno/fisiologia , Fosfatidilinositol 3-Quinases/fisiologia , Sobrevivência Celular , Citotoxinas/genética , Citotoxinas/farmacologia , Glioblastoma/genética , Glutationa Transferase/genética , Glutationa Transferase/farmacologia , Humanos , Interleucinas/farmacologia , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Proteína Quinase 8 Ativada por Mitógeno/fisiologia , Proteína Quinase 9 Ativada por Mitógeno/fisiologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/farmacologia , Transdução de Sinais/fisiologia , Fatores de Tempo , Células Tumorais Cultivadas
16.
J Neurosci ; 27(31): 8395-404, 2007 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-17670986

RESUMO

Although oligodendrocytes undergo apoptosis after spinal cord injury, molecular mechanisms responsible for their death have been unknown. We report that oligodendrocyte apoptosis is regulated oppositely by c-Jun N-terminal kinase 3 (JNK3) and protein interacting with the mitotic kinase, never in mitosis A I (Pin1), the actions of which converge on myeloid cell leukemia sequence-1 (Mcl-1). Activated after injury, JNK3 induces cytochrome c release by facilitating the degradation of Mcl-1, the stability of which is maintained in part by Pin1. Pin1 binds Mcl-1 at its constitutively phosphorylated site, Thr163Pro, and stabilizes it by inhibiting ubiquitination. After injury JNK3 phosphorylates Mcl-1 at Ser121Pro, facilitating the dissociation of Pin1 from Mcl-1. JNK3 thus induces Mcl-1 degradation by counteracting the protective binding of Pin1. These results are confirmed by the opposing phenotypes observed between JNK3-/- and Pin1-/- mice: oligodendrocyte apoptosis and cytochrome c release are reduced in JNK3-/- but elevated in Pin1-/- mice. This report thus unveils a mechanism by which cytochrome c release is under the opposite control of JNK3 and Pin1, regulators for which the activities are intricately coupled.


Assuntos
Apoptose/fisiologia , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Oligodendroglia/enzimologia , Peptidilprolil Isomerase/fisiologia , Traumatismos da Medula Espinal/enzimologia , Animais , Apoptose/genética , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Proteína Quinase 10 Ativada por Mitógeno/deficiência , Proteína Quinase 10 Ativada por Mitógeno/genética , Peptidilprolil Isomerase de Interação com NIMA , Oligodendroglia/citologia , Oligodendroglia/patologia , Peptidilprolil Isomerase/deficiência , Peptidilprolil Isomerase/genética , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/patologia , Ubiquitina/antagonistas & inibidores , Ubiquitina/metabolismo
17.
Blood ; 109(1): 168-75, 2007 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-16973965

RESUMO

The dynamic rearrangement of the actin cytoskeleton plays critical roles in T-cell receptor (TCR) signaling and immunological synapse (IS) formation in T cells. Following actin rearrangement in T cells upon TCR stimulation, we found a unique ring-shaped reorganization of actin called the "actin cloud," which was specifically induced by outside-in signals through lymphocyte function-associated antigen-1 (LFA-1) engagement. In T-cell-antigen-presenting cell (APC) interactions, the actin cloud is generated in the absence of antigen and localized at the center of the T-cell-APC interface, where it accumulates LFA-1 and tyrosine-phosphorylated proteins. The LFA-1-induced actin cloud formation involves ADAP (adhesion- and degranulation-promoting adaptor protein) phosphorylation, LFA-1/ADAP assembly, and c-Jun N-terminal kinase (JNK) activation, and occurs independent of TCR and its proximal signaling. The formation of the actin cloud lowers the threshold for subsequent T-cell activation. Thus, the actin cloud induced by LFA-1 engagement may serve as a possible platform for LFA-1-mediated costimulatory function for T-cell activation.


Assuntos
Citoesqueleto de Actina/fisiologia , Actinas/fisiologia , Ativação Linfocitária , Antígeno-1 Associado à Função Linfocitária/fisiologia , Linfócitos T/imunologia , Citoesqueleto de Actina/ultraestrutura , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Animais , Apresentação de Antígeno , Antígenos CD8/genética , Adesão Celular , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Proteínas Quinases JNK Ativadas por Mitógeno/fisiologia , Células Jurkat/efeitos dos fármacos , Células Jurkat/imunologia , Células Jurkat/metabolismo , Células Jurkat/ultraestrutura , Antígeno-1 Associado à Função Linfocitária/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Confocal , Microscopia de Fluorescência , Proteína Quinase 10 Ativada por Mitógeno/genética , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Fosforilação , Processamento de Proteína Pós-Traducional , Proteínas Tirosina Quinases/fisiologia , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Linfócitos T/ultraestrutura , Transfecção
18.
J Cereb Blood Flow Metab ; 27(5): 1022-32, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17063149

RESUMO

c-Jun N-terminal kinase 3 (JNK3) is a member of the stress-activated group of mitogen-activated protein kinases. c-Jun N-terminal kinase 3 is a potent mediator of apoptosis and the use of JNK inhibitors or jnk3 gene deletion each protect against brain injury in adults. However, little is known about the role of JNK3 or its mechanism of action in neonatal brain injury. The aim of the present study was to compare the vulnerability of neonatal JNK3 knockout (JNK3 KO) mice and wild-type (WT) mice to cerebral hypoxic-ischaemic injury (HII) using unilateral-carotid occlusion combined with transient hypoxia. The degree of neural tissue loss in JNK3 KO mice was substantially reduced compared with WT mice (JNK3 KO 27.8%+/-2.8% versus WT 48.3%+/-2.0%, P

Assuntos
Animais Recém-Nascidos/fisiologia , Hipóxia-Isquemia Encefálica/genética , Hipóxia-Isquemia Encefálica/patologia , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Fator 2 Ativador da Transcrição/genética , Animais , Apoptose/genética , Apoptose/fisiologia , Encéfalo/crescimento & desenvolvimento , Encéfalo/patologia , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína Quinase 10 Ativada por Mitógeno/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas do Tecido Nervoso/biossíntese , Neurônios/patologia , Fosforilação , Transdução de Sinais/fisiologia
19.
Biochem Biophys Res Commun ; 343(4): 1060-6, 2006 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-16579967

RESUMO

Cardiac stress consistently activates c-Jun NH(2)-terminal kinase (JNK) pathways, however the role of different members of the JNK family is unclear. In this study, we applied pressure overload (TAC) in mice with selective deletion of the three JNK genes (Jnk1(-/-), Jnk2(-/-), and Jnk3(-/-)). Following TAC, all three JNK knockout mouse lines developed cardiac hypertrophy similar to wild-type mice (WT), but only JNK1(-/-) mice displayed a significant reduction in fractional shortening after 3 and 7 days of pressure overload, associated with a significant increase in terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining and marked inflammatory infiltrate. After the acute deterioration stage, JNK1(-/-) mice underwent a slow recovery followed by a steady progression of cardiac dysfunction, becoming indistinguishable from WT after 12 weeks of TAC. These data suggest that JNK1 plays a protective role in response to pressure overload, preventing the early deterioration in cardiac function following an acute increase in afterload.


Assuntos
Cardiomegalia/fisiopatologia , Proteína Quinase 8 Ativada por Mitógeno/fisiologia , Miocárdio/patologia , Animais , Aorta/patologia , Apoptose , Pressão Sanguínea , Cardiomegalia/enzimologia , Constrição Patológica , Feminino , Marcação In Situ das Extremidades Cortadas , Masculino , Camundongos , Camundongos Knockout , Proteína Quinase 10 Ativada por Mitógeno/genética , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Proteína Quinase 8 Ativada por Mitógeno/genética , Proteína Quinase 9 Ativada por Mitógeno/genética , Proteína Quinase 9 Ativada por Mitógeno/fisiologia , Miocárdio/enzimologia , Fenótipo
20.
J Neurosci ; 25(23): 5533-43, 2005 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-15944381

RESUMO

Beta-amyloid precursor protein (APP) is a conserved and ubiquitous transmembrane glycoprotein strongly implicated in the pathogenesis of Alzheimer's disease but whose normal biological function is unknown. Analogy to the Notch protein suggests that APP is a cell-surface receptor that signals via sequential proteolytic cleavages that release its intracellular domain (AICD) to the nucleus. Because these cleavages are major targets for therapeutic inhibition, it is critical to elucidate their physiological function. AICD is stabilized by Fe65, interacts with the transcriptional factor Tip60, and translocates to the nucleus. Here, we show that endogenous AICD in primary neurons is detectable only during a short period of time during differentiation in culture. During this transient rise, a portion of AICD localizes to the nucleus. Subsequently, phosphorylation of the APP cytoplasmic domain at threonine 668 appears to disrupt the stabilizing interaction with Fe65 and thus downregulate AICD-mediated signaling. Furthermore, we find that the neuron-specific c-Jun N-terminal kinase JNK3, but not JNK1 or JNK2, mediates a substantial portion of this phosphorylation. We conclude that endogenous AICD undergoes tight temporal regulation during the differentiation of neurons and is negatively regulated by JNK3 via phosphorylation of APP at Thr668.


Assuntos
Precursor de Proteína beta-Amiloide/fisiologia , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Neurônios/metabolismo , Precursor de Proteína beta-Amiloide/biossíntese , Animais , Diferenciação Celular , Células Cultivadas , Chlorocebus aethiops , Cricetinae , Cricetulus , Camundongos , Neurônios/citologia , Fragmentos de Peptídeos/metabolismo , Fosforilação , Estrutura Terciária de Proteína , Ratos , Transdução de Sinais , Treonina/metabolismo , Regulação para Cima
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