Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Cell Biol Int ; 45(6): 1260-1268, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33559936

RESUMO

Cardiac hypertrophy (CH) is a common risk factor for heart failure and even sudden cardiac death. Molecules have emerged as vital regulators in cardiac disorders. LIM domain kinase 1 (Limk1) is reported as a pro-fibrotic mediator in patients with permanent atrial fibrillation and it has also been suggested to aggravate cardiac dysfunction in rats with chronic heart failure. The present study observed that Limk1 was significantly upregulated in the in vitro model of CH induced by angiotensin II (Ang-II). Interestingly, silencing Limk1 led to inhibition of the hypertrophic phenotypes in Ang-II-treated cardiomyocytes. Next, through a series of mechanistic assays including RIP assay, RNA pull-down assay, and luciferase reporter assay, miR-93-5p was verified to target Limk1. Furthermore, circ-Zfp644 was validated as the sponge of miR-93-5p. Circ-Zfp644 functioned as a ceRNA to upregulate Limk1 expression via sequestering miR-93-5p in Ang-II-treated cardiomyocytes. Finally, a range of rescue assays revealed that circ-Zfp644 stimulated hypertrophic effects in Ang-II-treated cardiomyocytes via upregulating Limk1 while miR-93-5p exerted the opposite effects via its inhibition on Limk1. On the whole, the present study revealed that circ-Zfp644 aggravated CH through modulating the miR-93-5p/Limk1 axis. The findings observed on the in vitro model of CH provided new potential for developing CH treatment.


Assuntos
Cardiomegalia/metabolismo , Quinases Lim/fisiologia , MicroRNAs/metabolismo , Animais , Linhagem Celular , Miócitos Cardíacos , Ratos
2.
Cancer Lett ; 492: 136-146, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32860848

RESUMO

Gastric cancer (GC) is the fifth most common primary malignancy in humans. Rho GDP dissociation inhibitor 2 (RhoGDI2) is overexpressed in multiple cancer types, but the role of RhoGDI2 in GC has not been elucidated. This study aims to determine the level of RhoGDI2 in GC and to confirm the effect of its inhibition or overexpression on GC cell migration, invasion and chemosensitivity. RhoGDI2 level is significantly enhanced in human GC tissue samples in comparison with normal gastric epithelium and corresponding para-cancerous samples. The expression of RhoGDI2 is correlated with clinicopathological parameters and prognosis. Transfection in combination with miRNA targeting of RhoGDI2 in GC cell lines remarkably downregulates GC cell migration and invasion and reduces the mRNA levels of Rac1, Pak1 and LIMK1. The inhibition of RhoGDI2 downregulates GC cell migration and invasion by attenuating the EMT cascade via the Rac1/Pak1/LIMK1 pathway. Knockdown of RhoGDI2 is a potential therapeutic strategy for GC.


Assuntos
Quinases Lim/fisiologia , Neoplasias Gástricas/patologia , Quinases Ativadas por p21/fisiologia , Proteínas rac1 de Ligação ao GTP/fisiologia , Inibidor beta de Dissociação do Nucleotídeo Guanina rho/fisiologia , Adulto , Idoso , Animais , Linhagem Celular Tumoral , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Masculino , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Invasividade Neoplásica , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/mortalidade
3.
Life Sci ; 254: 117778, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32407850

RESUMO

Long non-coding RNA (LncRNA) involved in types of physiological insults and diseases via regulating the responses of complex molecular, including cerebral ischemia-reperfusion (I/R) injury. LncRNA SNHG16 played a potential role in ketamine-induced neurotoxicity. In this study, we utilized an in vitro cell model of I/R to examine the specific function and mechanism of LncRNA SNHG16 in oxygen-glucose deprivation and reperfusion (OGD/R) induced SH-SY5Y cells. After in vitro treatment of OGD/R, the lower the SH-SY5Y cell survival, the higher cell the apoptosis and increased caspase-3 activity was observed. Also, OGD/R induced endoplasmic reticulum stress (ERS) through increasing GRP78 and CHOP expressions and down-regulated LncRNA SNHG16 in SH-SY5Y cells. Conversely, LncRNA SNHG16 overexpression promoted OGD/R induced SH-SY5Y cell survival, suppressed its apoptosis, and caspase-3 activity. GRP78 and CHOP expressions were significantly suppressed in LncRNA SNHG16 overexpressing cells. MiR-106b-5p expression was increased and LIMK1 expression was down-regulated in OGD/R induced SH-SY5Y cells, and these effects were reversed by LncRNA SNHG16 overexpression, respectively. Moreover, LIMK1 is a direct target of MiR-106b-5p, and knockdown of LIMK1 reversed the effects of LncRNA SNHG16 on OGD/R-induced SH-SY5Y cells biology. Altogether, these results confirmed an important neuroprotection role of LncRNA SNHG16 in OGD/R induced SH-SY5Y cells injury, and miR-106b-5p/LIMK1 signal axis was involved in the action of LncRNA SNHG16.


Assuntos
Sobrevivência Celular/fisiologia , Quinases Lim/fisiologia , MicroRNAs/fisiologia , RNA Longo não Codificante/biossíntese , RNA Longo não Codificante/fisiologia , Traumatismo por Reperfusão/metabolismo , Apoptose/fisiologia , Caspase 3/metabolismo , Células Cultivadas , Regulação para Baixo , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático , Técnicas de Silenciamento de Genes , Proteínas de Choque Térmico/biossíntese , Humanos , Quinases Lim/genética , Quinases Lim/metabolismo , MicroRNAs/metabolismo , Transdução de Sinais/fisiologia , Fator de Transcrição CHOP/biossíntese
4.
Cell Death Differ ; 27(1): 102-116, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31043701

RESUMO

Many cell types are known to undergo a series of morphological changes during the progression of apoptosis, leading to their disassembly into smaller membrane-bound vesicles known as apoptotic bodies (ApoBDs). In particular, the formation of circular bulges called membrane blebs on the surface of apoptotic cells is a key morphological step required for a number of cell types to generate ApoBDs. Although apoptotic membrane blebbing is thought to be regulated by kinases including ROCK1, PAK2 and LIMK1, it is unclear whether these kinases exhibit overlapping roles in the disassembly of apoptotic cells. Utilising both pharmacological and CRISPR/Cas9 gene editing based approaches, we identified ROCK1 but not PAK2 or LIMK1 as a key non-redundant positive regulator of apoptotic membrane blebbing as well as ApoBD formation. Functionally, we have established an experimental system to either inhibit or enhance ApoBD formation and demonstrated the importance of apoptotic cell disassembly in the efficient uptake of apoptotic materials by various phagocytes. Unexpectedly, we also noted that ROCK1 could play a role in regulating the onset of secondary necrosis. Together, these data shed light on both the mechanism and function of cell disassembly during apoptosis.


Assuntos
Apoptose , Membrana Celular/ultraestrutura , Quinases Lim/fisiologia , Quinases Ativadas por p21/fisiologia , Quinases Associadas a rho/fisiologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Cricetinae , Inibidores Enzimáticos/farmacologia , Humanos , Células Jurkat , Quinases Lim/antagonistas & inibidores , Necrose , Células THP-1 , Quinases Ativadas por p21/antagonistas & inibidores , Quinases Associadas a rho/antagonistas & inibidores
5.
Sci Rep ; 9(1): 3357, 2019 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-30833597

RESUMO

Inherited hearing loss is associated with gene mutations that result in sensory hair cell (HC) malfunction. HC structure is defined by the cytoskeleton, which is mainly composed of actin filaments and actin-binding partners. LIM motif-containing protein kinases (LIMKs) are the primary regulators of actin dynamics and consist of two members: LIMK1 and LIMK2. Actin arrangement is directly involved in the regulation of cytoskeletal structure and the maturation of synapses in the central nervous system, and LIMKs are involved in structural plasticity by controlling the activation of the actin depolymerization protein cofilin in the olfactory system and in the hippocampus. However, the expression pattern and the role of LIMKs in mouse cochlear development and synapse function also need to be further studied. We show here that the Limk genes are expressed in the mouse cochlea. We examined the morphology and the afferent synapse densities of HCs and measured the auditory function in Limk1 and Limk2 double knockout (DKO) mice. We found that the loss of Limk1 and Limk2 did not appear to affect the overall development of the cochlea, including the number of HCs and the structure of hair bundles. There were no significant differences in auditory thresholds between DKO mice and wild-type littermates. However, the expression of p-cofilin in the DKO mice was significantly decreased. Additionally, no significant differences were found in the number or distribution of ribbon synapses between the DKO and wild-type mice. In summary, our data suggest that the Limk genes play a different role in the development of the cochlea compared to their role in the central nervous system.


Assuntos
Cóclea/crescimento & desenvolvimento , Audição/fisiologia , Quinases Lim/genética , Fatores de Despolimerização de Actina/metabolismo , Actinas/metabolismo , Animais , Células Ciliadas Auditivas , Quinases Lim/deficiência , Quinases Lim/fisiologia , Camundongos , Camundongos Knockout , Sinapses
6.
Life Sci ; 186: 17-24, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28774704

RESUMO

AIMS: Maternal dietary restriction during pregnancy impairs nephron development and results in offspring with fewer nephrons. Cell turnover in the early developing kidney is altered by exposure to maternal dietary restriction and may be regulated by the LIM-kinase family of enzymes. We set out to establish whether disturbance of LIM-kinase activity might play a role in the impairment of nephron formation. MAIN METHODS: E12.5 metanephric kidneys and HK2 cells were grown in culture with the pharmacological LIM-kinase inhibitor BMS5. Organs were injected with DiI, imaged and cell numbers measured over 48h to assess growth. Cells undergoing mitosis were visualised by pH3 labelling. KEY FINDINGS: Growth of cultured kidneys reduced to 83% of controls after exposure to BMS5 and final cell number to 25% of control levels after 48h. Whilst control and BMS5 treated organs showed cells undergoing mitosis (100±11 cells/field vs 113±18 cells/field respectively) the proportion in anaphase was considerably diminished with BMS5 treatment (7.8±0.8% vs 0.8±0.6% respectively; P<0.01). This was consistent with effects on HK2 cells highlighting a severe impact of BMS5 on formation of the mitotic spindle and centriole positioning. DiI labelled cells migrated in 100% of control cultures vs 0% BMS5 treated organs. The number of nephrogenic precursor cells appeared depleted in whole organs and formation of new nephrons was blocked by exposure to BMS5. SIGNIFICANCE: Pharmacological blockade of LIM-kinase function in the early developing kidney results in failure of renal development. This is likely due to prevention of dividing cells from completion of mitosis with their resultant loss.


Assuntos
Desenvolvimento Fetal/fisiologia , Túbulos Renais Proximais , Quinases Lim/fisiologia , Mesonefro , Organogênese/fisiologia , Animais , Técnicas de Cultura de Células , Linhagem Celular , Inibidores Enzimáticos/farmacologia , Desenvolvimento Fetal/efeitos dos fármacos , Idade Gestacional , Humanos , Túbulos Renais Proximais/citologia , Túbulos Renais Proximais/enzimologia , Quinases Lim/antagonistas & inibidores , Mesonefro/embriologia , Mesonefro/enzimologia , Camundongos Endogâmicos ICR , Mitose/efeitos dos fármacos , Organogênese/efeitos dos fármacos , Técnicas de Cultura de Tecidos
7.
Neuropharmacology ; 125: 284-294, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28669900

RESUMO

Central sensitization represents a key mechanism mediating chronic pain, a major clinical problem lacking effective treatment options. LIM-domain kinases (LIMKs) selectively regulate several substrates, e.g. cofilin and cAMP response element-binding protein (CREB), that profoundly affect neural activities, such as synaptogenesis and gene expression, thus critical in the consolidation of long-term synaptic potentiation and memory in the brain. In this study, we demonstrate that LIMK deficiency significantly impaired the development of multiple forms of chronic pain. Mechanistic studies focusing on spared nerve injury (SNI) model reveal a pivotal role of LIMKs in the up-regulation of spontaneous excitatory synaptic transmission and synaptogenesis after pain induction. Depending on the pain induction methods, LIMKs can be transiently activated with distinct time courses. Accordingly, pharmacological inhibition of LIMKs targeting this critical period remarkably attenuated central sensitization in the spinal cord and alleviated pain behaviors. We propose selectively targeting LIMKs during their activation phase as a potential therapeutic strategy for clinical management of chronic pain, especially for chronic pain with predictable onset and development time courses, such as chronic post-surgical pain (PSP).


Assuntos
Sensibilização do Sistema Nervoso Central/fisiologia , Dor Crônica/prevenção & controle , Quinases Lim/antagonistas & inibidores , Quinases Lim/fisiologia , Medula Espinal/enzimologia , Fatores de Despolimerização de Actina/metabolismo , Animais , Dor Crônica/enzimologia , Dor Crônica/patologia , Modelos Animais de Doenças , Adjuvante de Freund , Temperatura Alta , Hiperalgesia/enzimologia , Hiperalgesia/patologia , Hiperalgesia/prevenção & controle , Quinases Lim/deficiência , Quinases Lim/genética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neuralgia/enzimologia , Neuralgia/patologia , Neuralgia/prevenção & controle , Distribuição Aleatória , Medula Espinal/efeitos dos fármacos , Medula Espinal/patologia , Sinapses/efeitos dos fármacos , Sinapses/enzimologia , Sinapses/patologia , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia , Técnicas de Cultura de Tecidos
8.
Stem Cells Dev ; 24(3): 354-71, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25209090

RESUMO

Body axes and germ layers evolve at gastrulation, and in mammals are driven by many genes; however, what orchestrates the genetic pathways during gastrulation remains elusive. Previously, we presented evidence that microRNA-17 (miRNA-17) family members, miR-17-5p, miR-20a, miR-93, and miR-106a were differentially expressed in mouse embryos and functioned to control differentiation of the stem cell population. Here, we identify function(s) that these miRNAs have during gastrulation. Fluorescent in situ hybridization miRNA probes reveal that these miRNAs are localized at the mid/posterior primitive streak (ps) in distinct populations of primitive ectoderm, mesendoderm, and mesoderm. Seven different miRNA prediction algorithms are identified in silico bone morphogenic protein receptor 2 (Bmpr2) as a target of these miRNAs. Bmpr2 is a member of the TGFß pathway and invokes stage-specific changes during gastrulation. Recently, Bmpr2 was shown regulating cytoskeletal dynamics, cell movement, and invasion. Our previous and current data led to a hypothesis by which members of the miR-17 family influence gastrulation by suppressing Bmpr2 expression at the primitive streak. This suppression influences fate decisions of cells by affecting genes downstream of BMPR2 as well as mesoderm invasion through regulation of actin dynamics.


Assuntos
Receptores de Proteínas Morfogenéticas Ósseas Tipo II/fisiologia , Células-Tronco Embrionárias/citologia , Gastrulação/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , MicroRNAs/fisiologia , Regiões 3' não Traduzidas , Animais , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/biossíntese , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/genética , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Linhagem da Célula/genética , Corpos Embrioides , Desenvolvimento Embrionário , Endoderma/metabolismo , Feminino , Hibridização in Situ Fluorescente , Quinases Lim/fisiologia , Masculino , Camundongos , MicroRNAs/antagonistas & inibidores , Simulação de Acoplamento Molecular , Linha Primitiva/metabolismo , Transdução de Sinais , Proteínas Smad/fisiologia , Transfecção
9.
Oncogene ; 34(34): 4531-44, 2015 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-25486435

RESUMO

Invadopodia are actin-rich cell membrane projections used by invasive cells to penetrate the basement membrane. Control of invadopodia stability is critical for efficient degradation of the extracellular matrix (ECM); however, the underlying molecular mechanisms remain poorly understood. Here, we uncover a new role for podoplanin, a transmembrane glycoprotein closely associated with malignant progression of squamous cell carcinomas (SCCs), in the regulation of invadopodia-mediated matrix degradation. Podoplanin downregulation in SCC cells impairs invadopodia stability, thereby reducing the efficiency of ECM degradation. We report podoplanin as a novel component of invadopodia-associated adhesion rings, where it clusters prior to matrix degradation. Early podoplanin recruitment to invadopodia is dependent on lipid rafts, whereas ezrin/moesin proteins mediate podoplanin ring assembly. Finally, we demonstrate that podoplanin regulates invadopodia maturation by acting upstream of the ROCK-LIMK-Cofilin pathway through the control of RhoC GTPase activity. Thus, podoplanin has a key role in the regulation of invadopodia function in SCC cells, controlling the initial steps of cancer cell invasion.


Assuntos
Carcinoma de Células Escamosas/patologia , Extensões da Superfície Celular/fisiologia , Matriz Extracelular/metabolismo , Glicoproteínas de Membrana/fisiologia , Carcinoma de Células Escamosas/metabolismo , Linhagem Celular Tumoral , Humanos , Quinases Lim/fisiologia , Microdomínios da Membrana/fisiologia , Transdução de Sinais , Proteínas rho de Ligação ao GTP/fisiologia , Quinases Associadas a rho/fisiologia , Proteína de Ligação a GTP rhoC
10.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 43(1): 119-25, 2014 01.
Artigo em Chinês | MEDLINE | ID: mdl-24616471

RESUMO

LIM kinase-1 (LIMK1) and LIM kinase-2 (LIMK2) are kinases that have serine/threonine and tyrosine dual specificity. Although they show significant structural similarity, LIMK1 and LIMK2 have different expression patterns, subcellular localization, and functions. Activation of LIM kinases regulates the downstream of Rho GTPases, and influences the architecture of the actin cytoskeleton by regulating the activity of cofilin. Recent studies have shown that LIM kinases play important roles in the nervous system. For example, development of the central nervous system is reliant upon the presence of LIMK1, and deletion of Limk1 gene is involved in the development of the human genetic disorder Williams syndrome. Therefore, it is of vital physiological significance to investigate the neuronal function of LIM kinases. In this review, we outline the structure, phosphorylation regulation and neuronal function of LIM kinases, so as to provide new ideas for the treatment of these neurological diseases.


Assuntos
Quinases Lim/fisiologia , Sistema Nervoso/enzimologia , Animais , Humanos , Quinases Lim/química , Quinases Lim/metabolismo
11.
Cell Death Differ ; 21(7): 1036-49, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24561342

RESUMO

Although the aberrant activation of cell cycle proteins has a critical role in neuronal death, effectors or mediators of cyclin D1/cyclin-dependent kinase 4 (CDK4)-mediated death signal are still unknown. Here, we describe a previously unsuspected role of LIM kinase 2 (LIMK2) in programmed necrotic neuronal death. Downregulation of p27(Kip1) expression by Rho kinase (ROCK) activation induced cyclin D1/CDK4 expression levels in neurons vulnerable to status epilepticus (SE). Cyclin D1/CDK4 complex subsequently increased LIMK2 expression independent of caspase-3 and receptor interacting protein kinase 1 activity. In turn, upregulated LIMK2 impaired dynamic-related protein-1 (DRP1)-mediated mitochondrial fission without alterations in cofilin phosphorylation/expression and finally resulted in necrotic neuronal death. Inhibition of LIMK2 expression and rescue of DRP1 function attenuated this programmed necrotic neuronal death induced by SE. Therefore, we suggest that the ROCK-p27(Kip1)-cyclin D1/CDK4-LIMK2-DRP1-mediated programmed necrosis may be new therapeutic targets for neuronal death.


Assuntos
Dinaminas/fisiologia , Quinases Lim/fisiologia , Dinâmica Mitocondrial , Necrose , Animais , Região CA1 Hipocampal/enzimologia , Região CA1 Hipocampal/patologia , Ciclina D1/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Expressão Gênica , Masculino , Proteínas Serina-Treonina Quinases/metabolismo , Ratos Sprague-Dawley , Proteína Serina-Treonina Quinases de Interação com Receptores , Estado Epiléptico/patologia , Quinases Associadas a rho/metabolismo
12.
PLoS One ; 8(8): e72850, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23991158

RESUMO

Drug resistance is a major obstacle for the successful treatment of many malignancies, including neuroblastoma, the most common extracranial solid tumor in childhood. Therefore, current attempts to improve the survival of neuroblastoma patients, as well as those with other cancers, largely depend on strategies to counter cancer cell drug resistance; hence, it is critical to understand the molecular mechanisms that mediate resistance to chemotherapeutics. The levels of LIM-kinase 2 (LIMK2) are increased in neuroblastoma cells selected for their resistance to microtubule-targeted drugs, suggesting that LIMK2 might be a possible target to overcome drug resistance. Here, we report that depletion of LIMK2 sensitizes SHEP neuroblastoma cells to several microtubule-targeted drugs, and that this increased sensitivity correlates with enhanced cell cycle arrest and apoptosis. Furthermore, we show that LIMK2 modulates microtubule acetylation and the levels of tubulin Polymerization Promoting Protein 1 (TPPP1), suggesting that LIMK2 may participate in the mitotic block induced by microtubule-targeted drugs through regulation of the microtubule network. Moreover, LIMK2-depleted cells also show an increased sensitivity to certain DNA-damage agents, suggesting that LIMK2 might act as a general pro-survival factor. Our results highlight the exciting possibility of combining specific LIMK2 inhibitors with anticancer drugs in the treatment of multi-drug resistant cancers.


Assuntos
Antineoplásicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/fisiologia , Quinases Lim/fisiologia , Neuroblastoma/patologia , Acetilação , Linhagem Celular Tumoral , Dano ao DNA , Humanos , Microtúbulos/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Regulação para Cima/efeitos dos fármacos
13.
J Neurosci ; 33(15): 6423-33, 2013 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-23575840

RESUMO

Actin dynamics provide an important mechanism for the modification of synaptic plasticity, which is regulated by the actin depolymerizing factor (ADF)/cofilin. However, the role of cofilin regulated actin dynamics in memory extinction process is still unclear. Here, we observed that extinction of conditioned taste aversive (CTA) memory led to temporally enhanced ADF/cofilin activity in the infralimbic cortex (IrL) of the rats. Moreover, temporally elevating ADF/cofilin activity in the IrL could accelerate CTA memory extinction by facilitating AMPAR synaptic surface recruitment, whereas inhibition of ADF/cofilin activity abolished AMPAR synaptic surface trafficking and impaired memory extinction. Finally, we observed that ADF/cofilin-regulated synaptic plasticity was not directly coupled to morphological changes of postsynaptic spines. These findings may help us understand the role of ADF/cofilin-regulated actin dynamics in memory extinction and suggest that appropriate manipulating ADF/cofilin activity might be a suitable way for therapeutic treatment of memory disorders.


Assuntos
Fatores de Despolimerização de Actina/fisiologia , Extinção Psicológica/fisiologia , Quinases Lim/fisiologia , Proteínas dos Microfilamentos/fisiologia , Monoéster Fosfórico Hidrolases/fisiologia , Transporte Proteico/fisiologia , Receptores de AMPA/fisiologia , Fatores de Despolimerização de Actina/metabolismo , Animais , Condicionamento Psicológico/fisiologia , Espinhas Dendríticas/ultraestrutura , Quinases Lim/metabolismo , Sistema Límbico/metabolismo , Sistema Límbico/fisiologia , Masculino , Proteínas dos Microfilamentos/metabolismo , Plasticidade Neuronal/fisiologia , Monoéster Fosfórico Hidrolases/metabolismo , Fosforilação , Ratos , Ratos Wistar , Receptores de AMPA/metabolismo
14.
Eur J Cancer ; 49(3): 752-63, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23063350

RESUMO

Poor prognosis of malignant gliomas is primarily attributed to their highly invasive nature. Despite the identification of new biomarkers and molecular targets for the improvement of the diagnosis, prognosis and treatment of glioma, the overall prognosis of the disease remains poor. This study is the first to show the significant upregulation of ARK5 paraffin-embedded archival glioma biopsies compared with those in adjacent non-cancerous brain tissues. Statistical analysis suggests that the upregulation of ARK5 correlates with the World Health Organization grade of glioma (P<0.001) and that patients with a high ARK5 level exhibit shorter survival time (P<0.01). In addition, ARK5 can promote glioma cell invasion by regulating cytoskeleton rearrangement and matrix metalloproteinase activation. ARK5 knockdown was found to reduce brain invasion in a glioma xenograft mouse model. Our results strongly suggest that ARK5 represents a novel and valuable biomarker to aid in the prediction of patient prognosis and is a potential therapeutic target against glioma.


Assuntos
Neoplasias Encefálicas/patologia , Glioma/patologia , Proteínas Quinases/fisiologia , Proteínas Repressoras/fisiologia , Actinas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Neoplasias Encefálicas/mortalidade , Linhagem Celular Tumoral , Movimento Celular , Progressão da Doença , Feminino , Glioma/mortalidade , Humanos , Fator de Crescimento Insulin-Like I/farmacologia , Quinases Lim/fisiologia , Masculino , Metaloproteinase 2 da Matriz/fisiologia , Metaloproteinase 9 da Matriz/fisiologia , Camundongos , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Proteínas Quinases/análise , Proteínas Repressoras/análise
15.
PLoS One ; 7(10): e47168, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23071748

RESUMO

In vitro studies have identified LIMK2 as a key downstream effector of Rho GTPase-induced changes in cytoskeletal organization. LIMK2 is phosphorylated and activated by Rho associated coiled-coil kinases (ROCKs) in response to a variety of growth factors. The biochemical targets of LIMK2 belong to a family of actin binding proteins that are potent modulators of actin assembly and disassembly. Although numerous studies have suggested that LIMK2 regulates cell morphology and motility, evidence supportive of these functions in vivo has remained elusive. In this study, a knockout mouse was created that abolished LIMK2 biochemical activity resulting in a profound inhibition of epithelial sheet migration during eyelid development. In the absence of LIMK2, nascent eyelid keratinocytes differentiate and acquire a pre-migratory phenotype but the leading cells fail to nucleate filamentous actin and remain immobile causing an eyes open at birth (EOB) phenotype. The failed nucleation of actin was associated with significant reductions in phosphorylated cofilin, a major LIMK2 biochemical substrate and potent modulator of actin dynamics. These results demonstrate that LIMK2 activity is required for keratinocyte migration in the developing eyelid.


Assuntos
Movimento Celular/genética , Pálpebras/citologia , Queratinócitos/citologia , Quinases Lim/fisiologia , Actinas/metabolismo , Animais , Pálpebras/embriologia , Pálpebras/patologia , Genótipo , Quinases Lim/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Fosforilação
16.
J Neurosci ; 32(15): 5284-97, 2012 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-22496574

RESUMO

Myelination is a complex process requiring coordination of directional motility and an increase in glial cell size to generate a multilamellar myelin sheath. Regulation of actin dynamics during myelination is poorly understood. However, it is known that myelin thickness is related to the abundance of neuregulin-1 (NRG1) expressed on the axon surface. Here we identify cofilin1, an actin depolymerizing and severing protein, as a downstream target of NRG1 signaling in rat Schwann cells (SCs). In isolated SCs, NRG1 promotes dephosphorylation of cofilin1 and its upstream regulators, LIM kinase (LIMK) and Slingshot-1 phosphatase (SSH1), leading to cofilin1 activation and recruitment to the leading edge of the plasma membrane. These changes are associated with rapid membrane expansion yielding a 35-50% increase in SC size within 30 min. Cofilin1-deficient SCs increase phosphorylation of ErbB2, ERK, focal adhesion kinase, and paxillin in response to NRG1, but fail to increase in size possibly due to stabilization of unusually long focal adhesions. Cofilin1-deficient SCs cocultured with sensory neurons do not myelinate. Ultrastructural analysis reveals that they unsuccessfully segregate or engage axons and form only patchy basal lamina. After 48 h of coculturing with neurons, cofilin1-deficient SCs do not align or elongate on axons and often form adhesions with the underlying substrate. This study identifies cofilin1 and its upstream regulators, LIMK and SSH1, as end targets of a NRG1 signaling pathway and demonstrates that cofilin1 is necessary for dynamic changes in the cytoskeleton needed for axon engagement and myelination by SCs.


Assuntos
Cofilina 1/genética , Cofilina 1/fisiologia , Bainha de Mielina/fisiologia , Neuregulina-1/genética , Neuregulina-1/fisiologia , Células de Schwann/fisiologia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Animais , Axônios/fisiologia , Axônios/ultraestrutura , Western Blotting , Polaridade Celular/genética , Proliferação de Células , Tamanho Celular , Técnicas de Cocultura , Corantes , Feminino , Imunofluorescência , Adesões Focais/genética , Gânglios Espinais/citologia , Quinases Lim/genética , Quinases Lim/fisiologia , Masculino , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/fisiologia , Microscopia Eletrônica , Bainha de Mielina/ultraestrutura , Monoéster Fosfórico Hidrolases/genética , Monoéster Fosfórico Hidrolases/fisiologia , Fosforilação , RNA Interferente Pequeno/genética , Ratos , Ratos Sprague-Dawley , Células de Schwann/ultraestrutura
17.
Dev Biol ; 366(2): 232-43, 2012 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-22537493

RESUMO

We previously provided evidence that cadherin-6B induces de-epithelialization of the neural crest prior to delamination and is required for the overall epithelial mesenchymal transition (EMT). Furthermore, de-epithelialization induced by cadherin-6B was found to be mediated by BMP receptor signaling independent of BMP. We now find that de-epithelialization is mediated by non-canonical BMP signaling through the BMP type II receptor (BMPRII) and not by canonical Smad dependent signaling through BMP Type I receptor. The LIM kinase/cofilin pathway mediates non-canonical BMPRII induced de-epithelialization, in response to either cadherin-6B or BMP. LIMK1 induces de-epithelialization in the neural tube and dominant negative LIMK1 decreases de-epithelialization induced by either cadherin-6B or BMP. Cofilin is the major known LIMK1 target and a S3A phosphorylation deficient mutated cofilin inhibits de-epithelialization induced by cadherin-6B as well as LIMK1. Importantly, LIMK1 as well as cadherin-6B can trigger ectopic delamination when co-expressed with the competence factor SOX9, showing that this cadherin-6B stimulated signaling pathway can mediate the full EMT in the appropriate context. These findings suggest that the de-epithelialization step of the neural crest EMT by cadherin-6B/BMPRII involves regulation of actin dynamics via LIMK/cofilin.


Assuntos
Proteínas Aviárias/fisiologia , Caderinas/fisiologia , Transição Epitelial-Mesenquimal/fisiologia , Crista Neural/fisiologia , Fatores de Despolimerização de Actina/fisiologia , Animais , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/fisiologia , Embrião de Galinha , Ectoderma/citologia , Ectoderma/fisiologia , Quinases Lim/fisiologia , Crista Neural/citologia , Transdução de Sinais
18.
J Cell Sci ; 125(Pt 6): 1579-90, 2012 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-22328514

RESUMO

The actin cytoskeleton in eukaryotic cells undergoes drastic rearrangement during mitosis. The changes to the actin cytoskeleton are most obvious in the adherent cells, where the actin stress fibres are disassembled, and the cortical actin network becomes more prominent with concomitant increase in cell rigidity as cells round up and enter mitosis. Although the regulatory connections between the actin cytoskeleton and the early mitotic events are apparent, the mechanisms that govern these links are not well understood. Here, we report that LIMK1 and LIMK2, the downstream effectors of RhoA and ROCK, regulate centrosome integrity and astral microtubule organization, respectively. Surprisingly, LIMK1 and cofilin are not involved downstream of RhoA and ROCK in the regulation of astral microtubule organization. Instead, we find that LIMK2 acts through TPPP in the regulation of astral microtubule organization, whereas both LIMK1 and LIMK2 affect centrosome focusing. Both phenotypes are tightly coupled to spindle orientation in the mitotic cells. Thus, our results reveal a new regulatory link between the actin cytoskeleton and the mitotic spindle during the early stages of mitosis.


Assuntos
Proteínas dos Microtúbulos/fisiologia , Fuso Acromático/fisiologia , Citoesqueleto de Actina/genética , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/fisiologia , Células HeLa , Humanos , Quinases Lim/genética , Quinases Lim/fisiologia , Metáfase/genética , Proteínas dos Microtúbulos/genética , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/fisiologia , Fuso Acromático/genética , Quinases Associadas a rho/genética , Quinases Associadas a rho/fisiologia , Proteína rhoA de Ligação ao GTP/genética , Proteína rhoA de Ligação ao GTP/fisiologia
19.
Zh Evol Biokhim Fiziol ; 48(6): 588-96, 2012.
Artigo em Russo | MEDLINE | ID: mdl-23401971

RESUMO

Molecular mechanisms of the synapse and dendrite maintenance and their disturbance in psychiatric and neurodegenerative diseases (ND) are intensively studied in searching for target genes of therapeutic actions. It is suggested that glia, alongside with well-studied pre- and postsynaptic neurons, is the third, poorly studied partner in synaptic transmission (the tripartite synapse) that is involved in the positive feedback between the first two partners. This bidirectional coupling between presynaptic neurons and their postsynaptic targets involve neurotrophins (NTF), such as glial cell-derived neurotrophic factor (GDNF) that is produced LIM kinase 1 (LIMK1, the key enzyme of actin remodeling). The cytoplasmic domain of neuregulins interacts with LIMK1. Since neurons and axons that do not receive a sufficient NTF amount are at risk of degeneration and synapse elimination, GDNF seems to be the best studied factor of the ND therapy. The delivery of GDNF stem cells to the neurodegeneration locus is very efficient. There has been proposed a new approach based on use of Drosophila heat shock (hs) promoter. This promoter responds to the mammalian body temperature as to the shock factor resulting in the constant expression of the GDNF gene. The Drosophila models allow studying any given component of the bidirectional communication between pre- and postsynaptic neurons in development of the main diagnostic ND symptom, such as defective memory resulted from synaptic atrophy. In the present study we used the Drosophila stocks imitating different disturbances of the nervous system: Canton-S (wild type), GDNF (transgenic flies that carry human glial-cell-line derived nerve factor (GDNF) gene under hs promoter), l(1)ts403 with dusturbance of HSPs mRNA extranuclear transport, a defect of intracellular stress report, and agn(ts3) mutation in LIMK1 gene. We have revealed functional connections at the behavioral level (learning/memory) depending on the GDNF and LIMK1 brain expression and HSPs transduction that might provide targets for complex approaches for the ND treatment.


Assuntos
Fator Neurotrófico Derivado de Linhagem de Célula Glial , Proteínas de Choque Térmico , Aprendizagem/fisiologia , Quinases Lim , Memória/fisiologia , Animais , Axônios/metabolismo , Axônios/fisiologia , Drosophila melanogaster/genética , Drosophila melanogaster/fisiologia , Regulação da Expressão Gênica , Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Fator Neurotrófico Derivado de Linhagem de Célula Glial/fisiologia , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/fisiologia , Humanos , Quinases Lim/genética , Quinases Lim/metabolismo , Quinases Lim/fisiologia , Mutação , Neuroglia/metabolismo , Neuroglia/patologia , Neurônios/citologia , Neurônios/metabolismo , Neurônios/patologia , Transdução de Sinais , Sinapses/metabolismo , Sinapses/fisiologia
20.
J Calif Dent Assoc ; 40(12): 921-7, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23362664

RESUMO

Mucocutaneous melanoma has a five-year survival rate of less than 10 percent. The alphavbeta3 integrin promotes invasion, which requires actin reorganization by cofilin. The authors previously showed that cofilin and alphavbeta3 promote invasion. K1735 melanoma has several clones, each with different levels of alphavbeta3. The authors found that expression of alphavbeta3 suppresses activation of RhoA thus inhibiting LIMK1 phosphorylation of cofilin. This indicates that alphavbeta3 integrin suppresses the RhoA/ ROCK/LIMK1 pathway.


Assuntos
Integrina alfaVbeta3/fisiologia , Quinases Lim/fisiologia , Melanoma/patologia , Transdução de Sinais/fisiologia , Proteínas rho de Ligação ao GTP/fisiologia , Fatores de Despolimerização de Actina/metabolismo , Fatores de Despolimerização de Actina/fisiologia , Amidas/farmacologia , Animais , Western Blotting , Linhagem Celular Tumoral , Membrana Celular/ultraestrutura , Núcleo Celular/ultraestrutura , Citoesqueleto/ultraestrutura , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Vetores Genéticos/genética , Humanos , Imunoprecipitação , Integrina alfaVbeta3/genética , Integrina alfaVbeta3/metabolismo , Quinases Lim/metabolismo , Camundongos , Microscopia de Fluorescência , Invasividade Neoplásica , Fosfoproteínas Fosfatases/metabolismo , Fosfoproteínas Fosfatases/fisiologia , Fosforilação , Piridinas/farmacologia , Transfecção , Proteínas rho de Ligação ao GTP/antagonistas & inibidores , Proteínas rho de Ligação ao GTP/metabolismo , Proteína rhoA de Ligação ao GTP
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...