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[PMID]:28468944
[Au] Autor:Montgomery DS; Yu L; Ghazi ZM; Thai TL; Al-Khalili O; Ma HP; Eaton DC; Alli AA
[Ad] Endereço:Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida.
[Ti] Título:ENaC activity is regulated by calpain-2 proteolysis of MARCKS proteins.
[So] Source:Am J Physiol Cell Physiol;313(1):C42-C53, 2017 Jul 01.
[Is] ISSN:1522-1563
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:We previously demonstrated a role for the myristoylated alanine-rich C kinase substrate (MARCKS) to serve as an adaptor protein in the anionic phospholipid phosphate-dependent regulation of the epithelial sodium channel (ENaC). Both MARCKS and ENaC are regulated by proteolysis. Calpains are a family of ubiquitously expressed intracellular Ca -dependent cysteine proteases involved in signal transduction. Here we examine the role of calpain-2 in regulating MARCKS and ENaC in cultured renal epithelial cells and in the mouse kidney. Using recombinant fusion proteins, we show that MARCKS, but not the ENaC subunits, are a substrate of calpain-2 in the presence of Ca Pharmacological inhibition of calpain-2 alters MARCKS protein expression in light-density sucrose gradient fractions from cell lysates of mouse cortical collecting duct cells. Calpain-dependent cleaved products of MARCKS are detectable in cultured renal cells. Ca mobilization and calpain-2 inhibition decrease the association between ENaC and MARCKS. The inhibition of calpain-2 reduces ENaC activity as demonstrated by single-channel patch-clamp recordings and transepithelial current measurements. These results suggest that calpain-2 proteolysis of MARCKS promotes its interaction with lipids and ENaC at the plasma membrane to allow for the phosphatidylinositol 4,5-bisphosphate (PIP2)-dependent regulation of ENaC activity in the kidney.
[Mh] Termos MeSH primário: Calpaína/genética
Canais Epiteliais de Sódio/genética
Peptídeos e Proteínas de Sinalização Intracelular/genética
Proteínas de Membrana/genética
Fosfatidilinositol 4,5-Difosfato/metabolismo
[Mh] Termos MeSH secundário: Potenciais de Ação/efeitos dos fármacos
Amilorida/farmacologia
Animais
Cálcio/metabolismo
Calpaína/metabolismo
Fracionamento Celular
Linhagem Celular
Membrana Celular/efeitos dos fármacos
Membrana Celular/metabolismo
Inibidores de Cisteína Proteinase/farmacologia
Citocalasina D/farmacologia
Células Epiteliais/citologia
Células Epiteliais/efeitos dos fármacos
Células Epiteliais/metabolismo
Canais Epiteliais de Sódio/metabolismo
Regulação da Expressão Gênica
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo
Túbulos Renais Coletores/citologia
Túbulos Renais Coletores/efeitos dos fármacos
Túbulos Renais Coletores/metabolismo
Proteínas de Membrana/metabolismo
Camundongos
Substrato Quinase C Rico em Alanina Miristoilada
Técnicas de Patch-Clamp
Proteólise/efeitos dos fármacos
Proteínas Recombinantes de Fusão/genética
Proteínas Recombinantes de Fusão/metabolismo
Transdução de Sinais
Xenopus laevis
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cysteine Proteinase Inhibitors); 0 (Epithelial Sodium Channels); 0 (Intracellular Signaling Peptides and Proteins); 0 (Marcks protein, mouse); 0 (Membrane Proteins); 0 (Phosphatidylinositol 4,5-Diphosphate); 0 (Recombinant Fusion Proteins); 125267-21-2 (Myristoylated Alanine-Rich C Kinase Substrate); 22144-77-0 (Cytochalasin D); 7DZO8EB0Z3 (Amiloride); EC 3.4.22.- (Calpain); EC 3.4.22.53 (Capn2 protein, mouse); SY7Q814VUP (Calcium)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:171212
[Lr] Data última revisão:
171212
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170505
[St] Status:MEDLINE
[do] DOI:10.1152/ajpcell.00244.2016


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[PMID]:28943429
[Au] Autor:Cui X; Zhang X; Bu H; Liu N; Li H; Guan X; Yan H; Wang Y; Zhang H; Ding Y; Cheng M
[Ad] Endereço:Clinical Medical School, Weifang Medical University, Weifang, Shandong, 261053, PR China.
[Ti] Título:Shear stress-mediated changes in the expression of complement regulatory protein CD59 on human endothelial progenitor cells by ECM-integrinα ß -F-actin pathway in vitro.
[So] Source:Biochem Biophys Res Commun;494(1-2):416-421, 2017 Dec 09.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Membrane regulatory proteins, such as CD46, CD55, and CD59, prevent excess complement activation and to protect cells from damage. Previous investigations confirmed that shear stress in the physiological range was more favorable for endothelial progenitor cells (EPCs) to repair injured vascular endothelial cells and operates mainly in atheroprotective actions. However, detailed events that contribute to shear stress-induced protection in EPCs, particularly the mechanisms of signal transduction, remain poorly understood. In this study, we observed shear stress-mediated changes in the expression of complement regulatory proteins CD46, CD55, and CD59 on human EPCs and focused on the mechanical transmission mechanism in transformed cells in response to the ECM-F-actin pathway in vitro. Shear stress was observed to promote the expression of complement regulatory protein CD59, but not CD46 or CD55, on EPCs. In addition, the shear stress-induced CD59 expression was confirmed to be associated with the ECM components and was alleviated in EPCs pretreated with GRGDSP, which inhibits ECM components-integrin interaction. Furthermore, shear stress also promotes the rearrangement and polymerization of F-actin. However, shear stress-induced CD59 expression was reduced when the F-actin stress fiber formation process was delayed by Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP) or destroyed by cytochalasin D (Cyto D), while Jasplakinolide (JAS) reversed the expression of CD59 through promotion of F-actin polymerization and its stabilizing capacities. Our results indicates that shear stress is an important mediator in EPC expression of CD59 regulated by the ECM-F-actin pathway, which is a key factor in preventing membrane attack complex (MAC) -mediated cell autolysis.
[Mh] Termos MeSH primário: Citoesqueleto de Actina/metabolismo
Actinas/genética
Antígenos CD59/genética
Células Progenitoras Endoteliais/metabolismo
Integrina alfaVbeta3/genética
Mecanotransdução Celular
[Mh] Termos MeSH secundário: Citoesqueleto de Actina/efeitos dos fármacos
Citoesqueleto de Actina/ultraestrutura
Actinas/metabolismo
Antígenos CD55/genética
Antígenos CD55/metabolismo
Antígenos CD59/metabolismo
Complexo de Ataque à Membrana do Sistema Complemento/efeitos dos fármacos
Citocalasina D/farmacologia
Depsipeptídeos/farmacologia
Células Progenitoras Endoteliais/citologia
Células Progenitoras Endoteliais/efeitos dos fármacos
Matriz Extracelular/química
Matriz Extracelular/efeitos dos fármacos
Matriz Extracelular/metabolismo
Sangue Fetal/citologia
Sangue Fetal/efeitos dos fármacos
Sangue Fetal/metabolismo
Regulação da Expressão Gênica
Seres Humanos
Integrina alfaVbeta3/metabolismo
Proteína Cofatora de Membrana/genética
Proteína Cofatora de Membrana/metabolismo
Oligopeptídeos/farmacologia
Cultura Primária de Células
Estresse Mecânico
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Actins); 0 (CD46 protein, human); 0 (CD55 Antigens); 0 (CD59 Antigens); 0 (Complement Membrane Attack Complex); 0 (Depsipeptides); 0 (Integrin alphaVbeta3); 0 (Membrane Cofactor Protein); 0 (Oligopeptides); 101754-01-2 (CD59 protein, human); 102396-24-7 (jasplakinolide); 22144-77-0 (Cytochalasin D); 91037-75-1 (glycyl-arginyl-glycyl-aspartyl-seryl-proline)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170926
[St] Status:MEDLINE


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[PMID]:28636921
[Au] Autor:Yu G; Yap YR; Pollock K; Hubel A
[Ad] Endereço:Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota.
[Ti] Título:Characterizing Intracellular Ice Formation of Lymphoblasts Using Low-Temperature Raman Spectroscopy.
[So] Source:Biophys J;112(12):2653-2663, 2017 Jun 20.
[Is] ISSN:1542-0086
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Raman microspectroscopy was used to quantify freezing response of cells to various cooling rates and solution compositions. The distribution pattern of cytochrome c in individual cells was used as a measure of cell viability in the frozen state and this metric agreed well with the population-averaged viability and trypan blue staining experiments. Raman imaging of cells demonstrated that intracellular ice formation (IIF) was common and did not necessarily result in cell death. The amount of intracellular ice as well as ice crystal size played a role in determining whether or not ice inside the cell was a lethal event. Intracellular ice crystals were colocated to the sections of cell membrane in close proximity to extracellular ice. Increasing the distance between extracellular ice and cell membrane decreased the incidence of IIF. Reducing the effective stiffness of the cell membrane by disrupting the actin cytoskeleton using cytochalasin D increased the amount of IIF. Strong intracellular osmotic gradients were observed when IIF was present. These observations support the hypothesis that interactions between the cell membrane and extracellular ice result in IIF. Raman spectromicroscopy provides a powerful tool for observing IIF and understanding its role in cell death during freezing, and enables the development, to our knowledge, of new and improved cell preservation protocols.
[Mh] Termos MeSH primário: Congelamento
Gelo
Espaço Intracelular/química
Análise Espectral Raman
[Mh] Termos MeSH secundário: Citoesqueleto de Actina/química
Citoesqueleto de Actina/efeitos dos fármacos
Citoesqueleto de Actina/metabolismo
Morte Celular/efeitos dos fármacos
Morte Celular/fisiologia
Membrana Celular/química
Membrana Celular/efeitos dos fármacos
Membrana Celular/metabolismo
Sobrevivência Celular/efeitos dos fármacos
Sobrevivência Celular/fisiologia
Criopreservação
Crioprotetores/farmacologia
Citocalasina D/farmacologia
Dextranos/farmacologia
Dimetil Sulfóxido/farmacologia
Elasticidade
Espaço Extracelular/química
Espaço Extracelular/efeitos dos fármacos
Espaço Extracelular/metabolismo
Glicerol/farmacologia
Seres Humanos
Espaço Intracelular/efeitos dos fármacos
Espaço Intracelular/metabolismo
Células Jurkat
Microscopia Confocal
Análise de Célula Única
Trealose/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cryoprotective Agents); 0 (Dextrans); 0 (Ice); 22144-77-0 (Cytochalasin D); B8WCK70T7I (Trehalose); PDC6A3C0OX (Glycerol); YOW8V9698H (Dimethyl Sulfoxide)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170823
[Lr] Data última revisão:
170823
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170622
[St] Status:MEDLINE


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[PMID]:28527708
[Au] Autor:Dalghi MG; Ferreira-Gomes M; Montalbetti N; Simonin A; Strehler EE; Hediger MA; Rossi JP
[Ad] Endereço:IQUIFIB - Instituto de Química y Fisicoquímica Biológicas, Conicet/UBA, Junín 956, 1113 Buenos Aires, Argentina; Institute of Biochemistry and Molecular Medicine, Swiss National Centre of Competence in Research, NCCR TransCure, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland. Electronic a
[Ti] Título:Cortical cytoskeleton dynamics regulates plasma membrane calcium ATPase isoform-2 (PMCA2) activity.
[So] Source:Biochim Biophys Acta;1864(8):1413-1424, 2017 08.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:We have previously shown that purified actin can directly bind to human plasma membrane Ca ATPase 4b (hPMCA4b) and exert a dual modulation on its Ca -ATPase activity: F-actin inhibits PMCA while short actin oligomers may contribute to PMCA activation. These studies had to be performed with purified proteins given the nature of the biophysical and biochemical approaches used. To assess whether a functional interaction between the PMCAs and the cortical cytoskeleton is of physiological relevance, we characterized this phenomenon in the context of a living cell by monitoring in real-time the changes in the cytosolic calcium levels ([Ca ] ). In this study, we tested the influence of drugs that change the actin and microtubule polymerization state on the activity and membrane expression of the PMCA transiently expressed in human embryonic kidney (HEK293) cells, which allowed us to observe and quantify these relationships in a live cell, for the first time. We found that disrupting the actin cytoskeleton with cytochalasin D significantly increased PMCA-mediated Ca extrusion (~50-100%) whereas pre-treatment with the F-actin stabilizing agent jasplakinolide caused its full inhibition. When the microtubule network was disrupted by pretreatment of the cells with colchicine, we observed a significant decrease in PMCA activity (~40-60% inhibition) in agreement with the previously reported role of acetylated tubulin on the calcium pump. In none of these cases was there a difference in the level of expression of the pump at the cell surface, thus suggesting that the specific activity of the pump was the regulated parameter. Our results indicate that PMCA activity is profoundly affected by the polymerization state of the cortical cytoskeleton in living cells.
[Mh] Termos MeSH primário: Citoesqueleto de Actina/metabolismo
Sinalização do Cálcio/efeitos dos fármacos
Cálcio/metabolismo
Membrana Celular/metabolismo
Microtúbulos/metabolismo
ATPases Transportadoras de Cálcio da Membrana Plasmática/metabolismo
[Mh] Termos MeSH secundário: Citoesqueleto de Actina/efeitos dos fármacos
Citoesqueleto de Actina/ultraestrutura
Actinas/genética
Actinas/metabolismo
Membrana Celular/efeitos dos fármacos
Membrana Celular/ultraestrutura
Colchicina/farmacologia
Citocalasina D/farmacologia
Depsipeptídeos/farmacologia
Regulação da Expressão Gênica
Células HEK293
Seres Humanos
Microtúbulos/efeitos dos fármacos
Microtúbulos/ultraestrutura
ATPases Transportadoras de Cálcio da Membrana Plasmática/antagonistas & inibidores
ATPases Transportadoras de Cálcio da Membrana Plasmática/genética
Imagem com Lapso de Tempo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Actins); 0 (Depsipeptides); 102396-24-7 (jasplakinolide); 22144-77-0 (Cytochalasin D); EC 3.6.3.8 (ATP2B2 protein, human); EC 3.6.3.8 (Plasma Membrane Calcium-Transporting ATPases); SML2Y3J35T (Colchicine); SY7Q814VUP (Calcium)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171004
[Lr] Data última revisão:
171004
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170522
[St] Status:MEDLINE


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[PMID]:28445756
[Au] Autor:Kanda H; Gu JG
[Ad] Endereço:Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama.
[Ti] Título:Membrane Mechanics of Primary Afferent Neurons in the Dorsal Root Ganglia of Rats.
[So] Source:Biophys J;112(8):1654-1662, 2017 Apr 25.
[Is] ISSN:1542-0086
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Membrane mechanics is an important biological factor regulating many cellular functions including cell motility, intercellular and intracellular signaling, gene expression, and membrane ion channel activity. Primary afferent neurons transduce sensory information about temperature, touch, and pain. These sensory functions may be profoundly affected by the states of primary afferent neuron mechanics. However, membrane mechanics of primary afferent neurons is largely unknown. In this study, we established the optical trapping technique for determining membrane mechanics of cultured primary afferent neurons of the dorsal root ganglia (DRG). We further determined the roles of cytoskeleton and membrane lipids in DRG neuron mechanics. We found that DRG neurons had a plasma membrane tension of ∼54 pN/µm, and the tension was significantly decreased to ∼29 pN/µm by cytochalasin D treatment to disrupt actin cytoskeleton and increased to ∼79 pN/µm by methyl-ß-cyclodextrin treatment to sequester membrane cholesterol. DRG neuron membrane stiffness was not significantly affected by the cytoskeleton disruption but was significantly increased after cholesterol sequestration. Our findings elucidate membrane mechanical properties of primary afferent neurons, which provide, to our knowledge, a new perspective on their sensory functions.
[Mh] Termos MeSH primário: Membrana Celular/fisiologia
Gânglios Espinais/fisiologia
Neurônios Aferentes/fisiologia
[Mh] Termos MeSH secundário: Actinas/metabolismo
Animais
Membrana Celular/efeitos dos fármacos
Células Cultivadas
Citocalasina D/farmacologia
Citoesqueleto/metabolismo
Elasticidade
Feminino
Gânglios Espinais/efeitos dos fármacos
Lipídeos de Membrana/metabolismo
Microscopia Eletrônica de Varredura
Neurônios Aferentes/efeitos dos fármacos
Pinças Ópticas
Fármacos do Sistema Nervoso Periférico/farmacologia
Ratos Sprague-Dawley
beta-Ciclodextrinas/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Actins); 0 (Membrane Lipids); 0 (Peripheral Nervous System Agents); 0 (beta-Cyclodextrins); 0 (methyl-beta-cyclodextrin); 22144-77-0 (Cytochalasin D)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170807
[Lr] Data última revisão:
170807
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170427
[St] Status:MEDLINE


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[PMID]:28388885
[Au] Autor:Gao M; Wu S; Ji J; Zhang J; Liu Q; Yue Y; Liu L; Liu X; Liu W
[Ad] Endereço:Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China.
[Ti] Título:The influence of actin depolymerization induced by Cytochalasin D and mechanical stretch on interleukin-8 expression and JNK phosphorylation levels in human retinal pigment epithelial cells.
[So] Source:BMC Ophthalmol;17(1):43, 2017 Apr 07.
[Is] ISSN:1471-2415
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: This study explores the role of actin cytoskeleton depolymerization induced by Cytochalasin D and mechanical stretch on the interleukin-8 (IL-8) expression and c-jun N-terminal kinase (JNK) phosphorylation levels in human retinal pigment epithelial (RPE) cells. METHODS: A Flexcell FX-5000 Tension system was used to apply cyclic stretch to cultured human RPE cells (ARPE-19) at 0.33 Hz with 20% elongation for 0 h, 6 h or 24 h. The cells were stretched alone or pre-treated with Cytochalasin D. The redistribution of the actin cytoskeleton was evaluated using phalloidin immunofluorescence staining. The protein expression levels of IL-8 and JNK in the RPE cells were determined via Western blotting. RESULTS: The cells in the control groups displayed abundant and uniform phalloidin staining. After exposure to mechanical stretch for 24 h, phalloidin staining revealed an unclear and irregular actin cytoskeleton. In all Cytochalasin D-treated cells, the shrinkage and disruption of the cytoskeletal structure was observed regardless of mechanical stress. The stimulation of the RPE cells with cyclic stretch alone did not induce a significant increase in IL-8 expression and JNK phosphorylation levels, which were similar to those of the control groups. After pre-treatment with Cytochalasin D alone, IL-8 expression and JNK phosphorylation levels were not significantly different at 6 h but were significantly increased by approximately 1.2-fold (1.18 ± 0.05; P<0.01) and 3.0-fold (3.01 ± 0.02; P<0.01) at 24 h, respectively. After the pre-incubation of the RPE cells with Cytochalasin D followed by exposure to cyclic stretch, IL-8 expression and JNK phosphorylation levels increased by approximately 1.3-fold (1.31 ± 0.02; P<0.01) and 1.3-fold (1.31 ± 0.02; P<0.01) at 6 h, respectively, and by 1.7-fold (1.69 ± 0.06; P<0.01) and 3.2-fold (3.21 ± 0.12; P<0.01) at 24 h, respectively. CONCLUSIONS: This study demonstrates that disruption of actin polymerization by cytochalasin D and mechanical stretch upregulates interleukin-8 expression and JNK phosphorylation levels in human RPE cells, which indicates that the integrity of the actin cytoskeleton may play important roles in the pro-inflammatory processes in RPE cells.
[Mh] Termos MeSH primário: Actinas/metabolismo
Citocalasina D/farmacologia
Interleucina-8/biossíntese
MAP Quinase Quinase 4/metabolismo
Epitélio Pigmentado da Retina/metabolismo
[Mh] Termos MeSH secundário: Western Blotting
Células Cultivadas
Citoesqueleto/patologia
Seres Humanos
Microscopia Confocal
Fosforilação
Epitélio Pigmentado da Retina/efeitos dos fármacos
Epitélio Pigmentado da Retina/patologia
Estresse Mecânico
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Actins); 0 (IL8 protein, human); 0 (Interleukin-8); 22144-77-0 (Cytochalasin D); EC 2.7.12.2 (MAP Kinase Kinase 4)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170901
[Lr] Data última revisão:
170901
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170409
[St] Status:MEDLINE
[do] DOI:10.1186/s12886-017-0437-z


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[PMID]:28315771
[Au] Autor:Menard SS; Watson GM
[Ad] Endereço:Department of Biology, University of Louisiana at Lafayette, 410 E. St. Mary Blvd., Lafayette, LA 70504, USA.
[Ti] Título:Evidence for two populations of hair bundles in the sea anemone, Nematostella vectensis.
[So] Source:Comp Biochem Physiol A Mol Integr Physiol;208:14-23, 2017 Jun.
[Is] ISSN:1531-4332
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Cytochalasin D (CD) was employed to disrupt F-actin within stereocilia of anemone hair bundles. CD treatment decreases the abundance of hair bundles (by 85%) while significantly impairing predation. The remaining hair bundles are 'CD-resistant.' Surprisingly, the morphology and F-actin content of resistant hair bundles are comparable to those of untreated controls. However, the resistant hair bundles fail to respond normally to the N-acetylated sugar, NANA, by elongating. Instead, they remain at resting length. Immediately after CD treatment, when only CD-resistant hair bundles are present, nematocyst discharge is normal into targets touched to tentacles in the absence of vibrations (i.e., baseline) but fails to increase normally in the presence of nearby vibrations at 56Hz, a key frequency. After CD treatment, the abundance of hair bundles recovers to control levels within three hours. At 2h after CD treatment, when CD-resistant and CD-sensitive hair bundles are both present, but a full-recovery is not yet complete, somewhat enhanced discharge of nematocysts occurs into targets touched to tentacles in the presence of nearby vibrations at 56Hz (at least as compared to the response of CD-treated animals to contact with test probes in the absence of vibrations). Additionally, at 2h after CD-treatment, prey capture recovers to normal. Thus, two populations of hair bundles may be present on tentacles of sea anemones: those that are CD-resistant and those that are CD-sensitive. The functions of these hair bundles may be distinct.
[Mh] Termos MeSH primário: Actinas/efeitos dos fármacos
Cabelo/fisiologia
Comportamento Predatório/efeitos dos fármacos
Anêmonas-do-Mar/fisiologia
[Mh] Termos MeSH secundário: Actinas/metabolismo
Animais
Metabolismo dos Carboidratos/efeitos dos fármacos
Citocalasina D/farmacologia
Cabelo/efeitos dos fármacos
Ácido N-Acetilneuramínico/metabolismo
Anêmonas-do-Mar/metabolismo
Vibração
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Actins); 22144-77-0 (Cytochalasin D); GZP2782OP0 (N-Acetylneuraminic Acid)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170807
[Lr] Data última revisão:
170807
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170320
[St] Status:MEDLINE


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[PMID]:28276730
[Au] Autor:Biolik G; Kokot M; Sznapka M; Swieszek A; Ziaja D; Pawlicki K; Ziaja K
[Ad] Endereço:a Department of General Vascular Surgery, Faculty of Medicine in Katowice , School of Health Science, Medical University of Silesia , Katowice , Poland.
[Ti] Título:Platelet reactivity in thromboelastometry. Revision of the FIBTEM test: a basic study.
[So] Source:Scand J Clin Lab Invest;77(3):216-222, 2017 May.
[Is] ISSN:1502-7686
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:This study aimed to investigate modifications to the FIBTEM test to better assess fibrinogen levels and the quality of fibrin polymerization in citrated blood using Multiplate impedance aggregometry to verify platelet inhibition. Blood samples from 26 healthy volunteers were subjected to thromboelastometry studies (EXTEM/FIBTEM tests) in accordance with the standard study protocol (cytochalasin D) and according to a modified protocol (synthetic IIbIIIa receptor antagonist vs. acetylsalicylic acid [ASA] + synthetic IIbIIIa receptor antagonist instead of cytochalasin D). Independent of thromboelastometry, Multiplate impedance aggregometry was used to assess the degree of restriction by the platelet blocked with the following treatments: (1) cytochalasin D, (2) synthetic IIbIIIa antagonist or (3) ASA + synthetic IIbIIIa antagonist to assess the aggregation response to activation with an agonist (ADP, collagen, thrombin receptor activating peptide-6 [TRAP-6], and arachidonic acid). Via aggregometry, cytochalasin D more weakly inhibited platelet aggregation than simultaneous administration of the -IIbIIIa receptor antagonist with ASA. However, total platelet aggregation inhibition was observed after simultaneous administration of cytochalasin D combined with a synthetic IIbIIIa receptor antagonist. In the thromboelastometry, a significant decrease of the A10, A20 and MCF parameters were observed in the EXTEM/FIBTEM tests after they were modified by the addition of a synthetic IIbIIIa receptor antagonist alone or in combination with ASA. In conclusion, in this Multiplate- and ROTEM-based laboratory approach, a two-way blockade (IIbIIIa-antagonist + cytochalasine D) was sufficient to completely inhibit procoagulant platelet function as observed by aggregometry and thromboelastometry.
[Mh] Termos MeSH primário: Aspirina/farmacologia
Plaquetas/efeitos dos fármacos
Citocalasina D/farmacologia
Ativação Plaquetária/efeitos dos fármacos
Agregação Plaquetária/efeitos dos fármacos
Tromboelastografia/normas
[Mh] Termos MeSH secundário: Difosfato de Adenosina/farmacologia
Adulto
Ácido Araquidônico/farmacologia
Testes de Coagulação Sanguínea
Plaquetas/citologia
Plaquetas/metabolismo
Colágeno/farmacologia
Feminino
Fibrina/metabolismo
Fibrinogênio/metabolismo
Seres Humanos
Integrina beta3/metabolismo
Masculino
Oligopeptídeos/farmacologia
Glicoproteína IIb da Membrana de Plaquetas/metabolismo
Cultura Primária de Células
Tromboelastografia/instrumentação
Tromboelastografia/métodos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Integrin beta3); 0 (Oligopeptides); 0 (Platelet Membrane Glycoprotein IIb); 0 (Ser-Phe-Phe-Leu-Arg-Asn); 22144-77-0 (Cytochalasin D); 27YG812J1I (Arachidonic Acid); 61D2G4IYVH (Adenosine Diphosphate); 9001-31-4 (Fibrin); 9001-32-5 (Fibrinogen); 9007-34-5 (Collagen); R16CO5Y76E (Aspirin)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170421
[Lr] Data última revisão:
170421
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170310
[St] Status:MEDLINE
[do] DOI:10.1080/00365513.2017.1292538


  9 / 2743 MEDLINE  
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[PMID]:28256232
[Au] Autor:Brückner BR; Nöding H; Janshoff A
[Ad] Endereço:Georg-August-Universität Göttingen, Institute of Physical Chemistry, Göttingen, Germany.
[Ti] Título:Viscoelastic Properties of Confluent MDCK II Cells Obtained from Force Cycle Experiments.
[So] Source:Biophys J;112(4):724-735, 2017 Feb 28.
[Is] ISSN:1542-0086
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The local mechanical properties of cells are frequently probed by force indentation experiments carried out with an atomic force microscope. Application of common contact models provides a single parameter, the Young's modulus, to describe the elastic properties of cells. The viscoelastic response of cells, however, is generally measured in separate microrheological experiments that provide complex shear moduli as a function of time or frequency. Here, we present a straightforward way to obtain rheological properties of cells from regular force distance curves collected in typical force indentation measurements. The method allows us to record the stress-strain relationship as well as changes in the weak power law of the viscoelastic moduli. We derive an analytical function based on the elastic-viscoelastic correspondence principle applied to Hertzian contact mechanics to model both indentation and retraction curves. Rheological properties are described by standard viscoelastic models and the paradigmatic weak power law found to interpret the viscoelastic properties of living cells best. We compare our method with atomic force microscopy-based active oscillatory microrheology and show that the method to determine the power law coefficient is robust against drift and largely independent of the indentation depth and indenter geometry. Cells were subject to Cytochalasin D treatment to provoke a drastic change in the power law coefficient and to demonstrate the feasibility of the approach to capture rheological changes extremely fast and precisely. The method is easily adaptable to different indenter geometries and acquires viscoelastic data with high spatiotemporal resolution.
[Mh] Termos MeSH primário: Elasticidade
[Mh] Termos MeSH secundário: Actinas/metabolismo
Animais
Citocalasina D/metabolismo
Cães
Células Madin Darby de Rim Canino
Reologia
Viscosidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Actins); 22144-77-0 (Cytochalasin D)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170713
[Lr] Data última revisão:
170713
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170304
[St] Status:MEDLINE


  10 / 2743 MEDLINE  
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[PMID]:28246604
[Au] Autor:Nobezawa D; Ikeda SI; Wada E; Nagano T; Miyata H
[Ad] Endereço:Department of Physics, Tohoku University, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
[Ti] Título:Directional Transport of a Bead Bound to Lamellipodial Surface Is Driven by Actin Polymerization.
[So] Source:Biomed Res Int;2017:7804251, 2017.
[Is] ISSN:2314-6141
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The force driving the retrograde flow of actin cytoskeleton is important in the cellular activities involving cell movement (e.g., growth cone motility in axon guidance, wound healing, or cancer metastasis). However, relative importance of the forces generated by actin polymerization and myosin II in this process remains elusive. We have investigated the retrograde movement of the poly-d-lysine-coated bead attached with the optical trap to the edge of lamellipodium of Swiss 3T3 fibroblasts. The velocity of the attached bead drastically decreased by submicromolar concentration of cytochalasin D, latrunculin A, or jasplakinolide, indicating the involvement of actin turnover. On the other hand, the velocity decreased only slightly in the presence of 50 M (-)-blebbistatin and Y-27632. Comparative fluorescence microscopy of the distribution of actin filaments and that of myosin II revealed that the inhibition of actin turnover by cytochalasin D, latrunculin A, or jasplakinolide greatly diminished the actin filament network. On the other hand, inhibition of myosin II activity by (-)-blebbistatin or Y-27632 little affected the actin network but diminished stress fibers. Based on these results, we conclude that the actin polymerization/depolymerization plays the major role in the retrograde movement, while the myosin II activity is involved in the maintenance of the dynamic turnover of actin in lamellipodium.
[Mh] Termos MeSH primário: Actinas/metabolismo
Microesferas
Polimerização
Pseudópodes/metabolismo
[Mh] Termos MeSH secundário: Células 3T3
Citoesqueleto de Actina/efeitos dos fármacos
Citoesqueleto de Actina/metabolismo
Animais
Transporte Biológico/efeitos dos fármacos
Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia
Citocalasina D/farmacologia
Espaço Intracelular/metabolismo
Quimografia
Camundongos
Miosina Tipo II/metabolismo
Polimerização/efeitos dos fármacos
Pseudópodes/efeitos dos fármacos
Tiazolidinas/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Actins); 0 (Bridged Bicyclo Compounds, Heterocyclic); 0 (Thiazolidines); 22144-77-0 (Cytochalasin D); EC 3.6.1.- (Myosin Type II); SRQ9WWM084 (latrunculin A)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170313
[Lr] Data última revisão:
170313
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170302
[St] Status:MEDLINE
[do] DOI:10.1155/2017/7804251



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