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1.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 41(5): 589-594, 2019 Oct 30.
Artigo em Chinês | MEDLINE | ID: mdl-31699187

RESUMO

Objective To investigate the effect of microRNA-133b(miR-133b)on cardiac fibrosis and its mechanism.Methods Human cardiac fibroblasts(CFs)were harvested.The proliferation of CFs was detected by CCK8 during the overexpression and knock-down of miR-133b.The expressions of connective tissue growth factor(CTGF),α-smooth muscle actin(α-SMA),collagen Ⅰ,and collagen Ⅲ were detected with qRT-PCR and Western blot analysis after miR-133b overexpression or downexpression.Target genes of miR-133b were predicted by bioinformatics software.Dual-luciferase activity assay were used to verify a target gene of miR-133b.Results qRT-PCR showed that the expression level of miR-133b in the miR-133b mimic group was significantly higher than that in the negative control group(t=26.219,P=0.000).The expression level of miR-133b in the miR-133b inhibitor group was significantly lower than that in the negative control group(t=6.738,P=0.003).After 21,45,69,93,and 117 hours of transfection,the proliferation ability of CFs significantly decreased in the miR-133b mimic group but significantly increased in the miR-133b group(all P<0.05,compared with the negative control group).After overexpression of miR-133b,the mRNA and protein levels of CTGF(t=9.213,P=0.001;t=8.195,P=0.001),α-SMA(t=6.511,P =0.003;t=4.434,P=0.011),collagenⅠ(t=3.172,P=0.034;t=4.053,P=0.015)and collagen Ⅲ(t=6.404,P=0.003;t=5.319,P=0.006)were significantly down-regulated.After the expression of miR-133b was knocked down,the mRNA and protein levels of CTGF(t=9.439,P=0.001;t=14.100,P=0.000),α-SMA(t=4.519,P=0.011;t=4.377,P=0.012),collagen Ⅰ(t=5.966,P=0.004;t=5.514,P=0.005)and collagen Ⅲ(t=4.622,P=0.010;t=4.996,P=0.008)were significantly increased.The relative luciferase activity of the cells co-transfected with miR-133b mimic and WT 3'UTR expression vector was significantly lower than that of the cells co-transfected with mimic control and WT 3'UTR expression vectors(t=5.654,P=0.005);however,there was no significant difference in relative luciferase activity between cells co-transfected with miR-133b mimic and MUT 3'UTR expression vectors and cells co-transfected with mimic control and MUT 3'UTR expression vectors(t=0.380,P=0.724).Conclusion miR-133b may affect the activation and proliferation of CFs by targeting CTGF and thus improve cardiac fibrosis.


Assuntos
Fibroblastos/citologia , MicroRNAs/genética , Miocárdio/patologia , Actinas/metabolismo , Proliferação de Células , Células Cultivadas , Colágeno/metabolismo , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Fibrose , Humanos
2.
Cell Physiol Biochem ; 53(4): 623-637, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31550089

RESUMO

BACKGROUND/AIMS: In articular cartilage, chondrocytes are the predominant cell type. A long-term stay in space can lead to bone loss and cartilage breakdown. Due to the poor regenerative capacity of cartilage, this may impair the crewmembers' mobility and influence mission activities. Beside microgravity other factors such as cosmic radiation and vibration might be important for cartilage degeneration. Vibration at different frequencies showed various effects on cartilage in vivo, but knowledge about its impact on chondrocytes in vitro is sparse. METHODS: Human chondrocytes were exposed to a vibration device, simulating the vibration profile occurring during parabolic flights, for 24 h (VIB) and compared to static controls. Phase-contrast microscopy, immunofluorescence, F-actin and TUNEL staining as well as quantitative real-time PCR were performed to examine effects on morphology, cell viability and shape as well as gene expression. The results were compared to earlier studies using semantic analyses. RESULTS: No morphological changes or cytoskeletal alterations were observed in VIB and no apoptotic cells were found. A reorganization and increase in fibronectin were detected in VIB samples by immunofluorescence technique. PXN, VCL, ANXA1, ANXA2, BAX, and BCL2 revealed differential regulations. CONCLUSION: Long-term VIB did not damage human chondrocytes in vitro. The reduction of ANXA2, and up-regulation of ANXA1, PXN and VCL mRNAs suggest that long-term vibration might even positively influence cultured chondrocytes.


Assuntos
Condrócitos/metabolismo , Vibração , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Anexina A2/genética , Anexina A2/metabolismo , Linhagem Celular , Condrócitos/citologia , Condrócitos/patologia , Colágeno Tipo II/genética , Colágeno Tipo II/metabolismo , Redes Reguladoras de Genes , Humanos , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Vimentina/genética , Vimentina/metabolismo
3.
Nat Cell Biol ; 21(9): 1068-1077, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31481797

RESUMO

Recent development of innovative tools for live imaging of actin filaments (F-actin) enabled the detection of surprising nuclear structures responding to various stimuli, challenging previous models that actin is substantially monomeric in the nucleus. We review these discoveries, focusing on double-strand break (DSB) repair responses. These studies revealed a remarkable network of nuclear filaments and regulatory mechanisms coordinating chromatin dynamics with repair progression and led to a paradigm shift by uncovering the directed movement of repair sites.


Assuntos
Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Núcleo Celular/metabolismo , Reparo do DNA/fisiologia , Animais , Cromatina/metabolismo , Quebras de DNA de Cadeia Dupla , Humanos
4.
BMC Med Genet ; 20(1): 138, 2019 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-31409279

RESUMO

BACKGROUND: Reference genes are often interchangeably called housekeeping genes due to 1) the essential cellular functions their proteins provide and 2) their constitutive expression across a range of normal and pathophysiological conditions. However, given the proliferative drive of malignant cells, many reference genes such as beta-actin (ACTB) and glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) which play critical roles in cell membrane organization and glycolysis, may be dysregulated in tumors versus their corresponding normal controls METHODS: Because Next Generation Sequencing (NGS) technology has several advantages over hybridization-based technologies, such as independent detection and quantitation of transcription levels, greater sensitivity, and increased dynamic range, we evaluated colorectal cancers (CRC) and their histologically normal tissue counterparts by NGS to evaluate the expression of 21 "classical" reference genes used as normalization standards for PCR based methods. Seventy-nine paired tissue samples of CRC and their patient matched healthy colonic tissues were subjected to NGS analysis of their mRNAs. RESULTS: We affirmed that 17 out of 21 classical reference genes had upregulated expression in tumors compared to normal colonic epithelial tissue and dramatically so in some cases. Indeed, tumors were distinguished from normal controls in both unsupervised hierarchical clustering analyses (HCA) and principal component analyses (PCA). We then identified 42 novel potential reference genes with minimal coefficients of variation (CV) across 79 CRC tumor pairs. Though largely consistently expressed across tumors and normal control tissues, a subset of high stage tumors (HSTs) as well as some normal tissue samples (HSNs) located adjacent to these HSTs demonstrated dysregulated expression, thus identifying a subset of tumors with a potentially distinct and aggressive biological profile. CONCLUSION: While classical CRC reference genes were found to be differentially expressed between tumors and normal controls, novel reference genes, identified via NGS, were more consistently expressed across malignant and normal colonic tissues. Nonetheless, a subset of HST had profound dysregulation of such genes as did many of the histologically normal tissues adjacent to such HSTs, indicating that the HSTs so distinguished may have unique biological properties and that their histologically normal tissues likely harbor a small population of microscopically undetected but metabolically active tumors.


Assuntos
Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica/genética , Estudos de Associação Genética , Predisposição Genética para Doença/genética , Actinas/genética , Actinas/metabolismo , Biomarcadores Tumorais/genética , Colo/patologia , Neoplasias Colorretais/patologia , Feminino , Perfilação da Expressão Gênica , Genes Essenciais/genética , Gliceraldeído-3-Fosfato Desidrogenases/genética , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , RNA Mensageiro , Análise de Sequência de RNA
5.
Results Probl Cell Differ ; 67: 27-48, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31435791

RESUMO

Formin homology proteins (formins) are a highly conserved family of cytoskeletal remodeling proteins that are involved in a diverse array of cellular functions. Formins are best known for their ability to regulate actin dynamics, but the same functional domains also govern stability and organization of microtubules. It is thought that this dual activity allows them to coordinate the activity of these two major cytoskeletal networks and thereby influence cellular architecture. Golgi ribbon assembly is dependent upon cooperative interactions between actin filaments and cytoplasmic microtubules originating both at the Golgi itself and from the centrosome. Similarly, centrosome assembly, centriole duplication, and centrosome positioning are also reliant on a dialogue between both cytoskeletal networks. As presented in this chapter, a growing body of evidence suggests that multiple formin proteins play essential roles in these central cellular processes.


Assuntos
Centríolos/metabolismo , Proteínas do Citoesqueleto/metabolismo , Citoesqueleto/metabolismo , Complexo de Golgi/metabolismo , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Microtúbulos/metabolismo
6.
Results Probl Cell Differ ; 67: 81-93, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31435793

RESUMO

In vertebrate cells, the Golgi apparatus is located in close proximity to the centriole. The architecture of the Golgi/centriole complex depends on a multitude of factors, including the actin filament cytoskeleton. In turn, both the Golgi and centriole act as the actin nucleation centers. Actin organization and polymerization also depend on the small GTPase RhoA pathway. In this chapter, we summarize the most current knowledge on how the genetic, magnetic, or pharmacologic interference with RhoA pathway and actin cytoskeleton directly or indirectly affects architecture, structure, and function of the Golgi/centriole complex.


Assuntos
Actinas/metabolismo , Centríolos/metabolismo , Complexo de Golgi/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo , Citoesqueleto de Actina/metabolismo
7.
J Agric Food Chem ; 67(35): 9789-9795, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31373816

RESUMO

Pulmonary fibrosis is a chronic lung disease characterized by abnormal accumulation of the extracellular matrix (ECM). Chronic damage of the alveolar epithelium leads to a process called "epithelial-mesenchymal transition" (EMT) and increases synthesis and deposition of ECM proteins. Therefore, inhibition of EMT might be a promising therapeutic approach for the treatment of pulmonary fibrosis. ß-Sitosterol is one of the most abundant phytosterols in the plant kingdom and the major constituent in corn silk, which is derived from the stigma and style of maize (Zea mays). In this study, we elucidated that ß-sitosterol inhibited transforming growth factor-ß1 (TGF-ß1)-induced EMT and consequently had an antifibrotic effect. ß-Sitosterol (1-10 µg/mL) significantly downregulated the TGF-ß1-induced fibrotic proteins, such as collagen, fibronectin, and α-smooth muscle actin in human alveolar epithelial cells (p < 0.01). After 24 h, relative wound density (RWD) was increased in TGF-ß1 treated group (82.16 ± 5.70) compare to the control group (64.63 ± 2.21), but RWD was decreased in ß-sitosterol cotreated group (10 µg/mL: 71.54 ± 7.39; 20 µg/mL: 65.69 ± 6.42). In addition, the changes of the TGF-ß1-induced morphological shape and protein expression of EMT markers, N-cadherin, vimentin, and E-cadherin, were significantly blocked by ß-sitosterol treatment (p < 0.01). The effects of ß-sitosterol on EMT were found to be associated with the TGF-ß1/Snail pathway, which is regulated by Smad and non-Smad signaling pathways. Taken together, these findings suggest that ß-sitosterol can be used to attenuate pulmonary fibrosis through suppression of EMT by inhibiting the TGF-ß1/Snail pathway.


Assuntos
Células Epiteliais Alveolares/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Extratos Vegetais/farmacologia , Alvéolos Pulmonares/efeitos dos fármacos , Fibrose Pulmonar/fisiopatologia , Sitosteroides/farmacologia , Zea mays/química , Actinas/genética , Actinas/metabolismo , Células Epiteliais Alveolares/citologia , Células Epiteliais Alveolares/metabolismo , Caderinas/genética , Caderinas/metabolismo , Linhagem Celular , Fibronectinas/genética , Fibronectinas/metabolismo , Humanos , Extratos Vegetais/química , Alvéolos Pulmonares/metabolismo , Alvéolos Pulmonares/fisiopatologia , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/genética , Fibrose Pulmonar/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo
8.
Life Sci ; 231: 116674, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31344427

RESUMO

Hypertrophic scar formation is a fibroproliferative disorder caused by abnormal wound healing. At present, there are limited treatment strategies for hypertrophic scars. In this study, we identified an endogenous peptide, LYENRL, through peptidomics screening that is downregulated in scar skin tissues. The peptide exhibited concentration dependent inhibitory effects on the proliferation, migration and extracellular matrix (ECM) production of scar fibroblasts. By eukaryotic transcriptome sequencing analysis, we noted that LYENRL downregulated gene sets in scar fibroblasts were associated with the transforming growth factor-ß (TGF-ß) signaling pathway. Further experiments revealed that LYENRL was able to inhibit the activation of TGF-ß1/Smad signaling and TGF-ß1-induced activation of scar fibroblasts at the source by blocking the binding of AP-1 to the corresponding region of the Tgfb1 promoter, which in turn inhibited gene expression of Tgfb1. Taken together, we concluded that the effects of LYENRL on scar fibroblasts make it a potential peptide drug for hypertrophic scar treatment.


Assuntos
Cicatriz Hipertrófica/metabolismo , Cicatriz Hipertrófica/patologia , Peptídeos/farmacologia , Actinas/metabolismo , Linhagem Celular , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Matriz Extracelular/metabolismo , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/fisiologia , Humanos , Peptídeos/metabolismo , Cultura Primária de Células , Transdução de Sinais/efeitos dos fármacos , Pele/metabolismo , Proteínas Smad/metabolismo , Proteínas Smad/fisiologia , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta1/fisiologia
9.
Parasitol Res ; 118(9): 2651-2667, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31270680

RESUMO

Representatives of Apicomplexa perform various kinds of movements that are linked to the different stages of their life cycle. Ancestral apicomplexan lineages, including gregarines, represent organisms suitable for research into the evolution and diversification of motility within the group. The vermiform trophozoites and gamonts of the archigregarine Selenidium pygospionis perform a very active type of bending motility. Experimental assays and subsequent light, electron, and confocal microscopic analyses demonstrated the fundamental role of the cytoskeletal proteins actin and tubulin in S. pygospionis motility and allowed us to compare the mechanism of its movement to the gliding machinery (the so-called glideosome concept) described in apicomplexan zoites. Actin-modifying drugs caused a reduction in the movement speed (cytochalasin D) or stopped the motility of archigregarines completely (jasplakinolide). Microtubule-disrupting drugs (oryzalin and colchicine) had an even more noticeable effect on archigregarine motility. The fading and disappearance of microtubules were documented in ultrathin sections, along with the formation of α-tubulin clusters visible after the immunofluorescent labelling of drug-treated archigregarines. The obtained data indicate that subpellicular microtubules most likely constitute the main motor structure involved in S. pygospionis bending motility, while actin has rather a supportive function.


Assuntos
Apicomplexa/crescimento & desenvolvimento , Apicomplexa/fisiologia , Citoesqueleto/metabolismo , Proteínas de Protozoários/metabolismo , Actinas/metabolismo , Animais , Apicomplexa/ultraestrutura , Citoesqueleto/ultraestrutura , Tomografia com Microscopia Eletrônica , Microtúbulos/metabolismo , Parasitos , Trofozoítos/crescimento & desenvolvimento , Trofozoítos/metabolismo , Trofozoítos/ultraestrutura , Tubulina (Proteína)/metabolismo
10.
Nat Commun ; 10(1): 3027, 2019 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-31289275

RESUMO

Fibrosis accompanying wound healing can drive the failure of many different organs. Activated fibroblasts are the principal determinants of post-injury pathological fibrosis along with physiological repair, making them a difficult therapeutic target. Although activated fibroblasts are phenotypically heterogeneous, they are not recognized as distinct functional entities. Using mice that express GFP under the FSP1 or αSMA promoter, we characterized two non-overlapping fibroblast subtypes from mouse hearts after myocardial infarction. Here, we report the identification of FSP1-GFP+ cells as a non-pericyte, non-hematopoietic fibroblast subpopulation with a predominant pro-angiogenic role, characterized by in vitro phenotypic/cellular/ultrastructural studies and in vivo granulation tissue formation assays combined with transcriptomics and proteomics. This work identifies a fibroblast subtype that is functionally distinct from the pro-fibrotic αSMA-expressing myofibroblast subtype. Our study has the potential to shift our focus towards viewing fibroblasts as molecularly and functionally heterogeneous and provides a paradigm to approach treatment for organ fibrosis.


Assuntos
Fibroblastos/metabolismo , Infarto do Miocárdio/patologia , Miocárdio/patologia , Neovascularização Fisiológica/fisiologia , Cicatrização/fisiologia , Actinas/genética , Actinas/metabolismo , Animais , Transplante de Medula Óssea , Proteínas de Ligação ao Cálcio/metabolismo , Diferenciação Celular , Modelos Animais de Doenças , Fibroblastos/patologia , Fibrose/etiologia , Fibrose/patologia , Proteínas de Fluorescência Verde/genética , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/fisiopatologia , Miocárdio/citologia , Proteína A4 de Ligação a Cálcio da Família S100/genética , Proteína A4 de Ligação a Cálcio da Família S100/metabolismo , Quimeras de Transplante
11.
Biomed Environ Sci ; 32(6): 419-426, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31262387

RESUMO

OBJECTIVE: Silicosis, caused by inhalation of silica dust, is the most serious occupational disease in China and the aim of present study was to explore the protective effect of Ang (1-7) on silicotic fibrosis and myofibroblast differentiation induced by Ang II. METHODS: HOPE-MED 8050 exposure control apparatus was used to establish the rat silicosis model. Pathological changes and collagen deposition of the lung tissue were examined by H.E. and VG staining, respectively. The localizations of ACE2 and α-smooth muscle actin (α-SMA) in the lung were detected by immunohistochemistry. Expression levels of collagen type I, α-SMA, ACE2, and Mas in the lung tissue and fibroblasts were examined by western blot. Levels of ACE2, Ang (1-7), and Ang II in serum were determined by ELISA. Co-localization of ACE2 and α-SMA in fibroblasts was detected by immunofluorescence. RESULTS: Ang (1-7) induced pathological changes and enhanced collagen deposition in vivo. Ang (1-7) decreased the expressions of collagen type I and α-SMA and increased the expressions of ACE2 and Mas in the silicotic rat lung tissue and fibroblasts stimulated by Ang II. Ang (1-7) increased the levels of ACE2 and Ang (1-7) and decreased the level of Ang II in silicotic rat serum. A779 enhanced the protective effect of Ang (1-7) in fibroblasts stimulated by Ang II. CONCLUSION: Ang (1-7) exerted protective effect on silicotic fibrosis and myofibroblast differentiation induced by Ang II by regulating ACE2-Ang (1-7)-Mas axis.


Assuntos
Angiotensina II/sangue , Angiotensina I/uso terapêutico , Pulmão/metabolismo , Miofibroblastos/efeitos dos fármacos , Fragmentos de Peptídeos/uso terapêutico , Silicose/prevenção & controle , Actinas/metabolismo , Angiotensina I/sangue , Angiotensina I/farmacologia , Animais , Animais Recém-Nascidos , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Colágeno Tipo I/metabolismo , Modelos Animais de Doenças , Pulmão/patologia , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/farmacologia , Peptidil Dipeptidase A/metabolismo , Ratos Wistar , Silicose/metabolismo , Silicose/patologia
12.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 44(5): 485-490, 2019 May 28.
Artigo em Chinês | MEDLINE | ID: mdl-31303610

RESUMO

OBJECTIVE: To explore the magnetic resonance imaging (MRI) characteristics of glioma with Brg/Brm-associated factor 53a (BAF53a) expression.
 Methods: A total of 121 patients with glioma was divided into a BAF53a high expression group (n=79) and a low expression group (n=42) according to the results of immunohistochemistry. Then the MRI characteristics, including lesion location, number, boundary, maximum diameter, peripheral edema, midline structure shift, homogeneity, cystic necrosis, hemorrhage, strengthening degree, ependymal strengthening, pia mater enhancement, deep white matter invasion and lesion across the midline (total 14 items), were analyzed.
 Results: The results showed that there were significance difference in lesion border, lesion edema, enhancement of the lesion, and deep white matter invasion between the 2 groups (all P<0.05).
 Conclusion: The MRI characteristics, such as lesion border, lesion edema degree, enhancement degree of the lesion and deep white matter invasion, might be associated with BAF53a expression in gliomas.


Assuntos
Actinas/metabolismo , Neoplasias Encefálicas , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ligação a DNA/metabolismo , Glioma , Humanos , Imagem por Ressonância Magnética , Necrose
13.
Vet Microbiol ; 235: 127-135, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282370

RESUMO

Lawsonia intracellularis is an obligate intracellular Gram-negative bacterium that has been identified as the etiological agent of the contagious disease proliferative enteropathy (PE) in a wide range of animals, mainly pigs. The genome sequence of L. intracellularis indicates that this bacterium possess a type III secretion system (T3SS), which may assist the bacterium during cell invasion and host innate immune system evasion and could be a mechanism for inducing cellular proliferation. However, the effectors secreted by the T3SS (T3Es) of L. intracellularis have not been reported. T3Es often target conserved eukaryotic cellular processes, and yeast is an established and robust model system in which to reveal their function. By screening the growth inhibition of an ordered array of Saccharomyces cerevisiae strains expressing the hypothetical genes of L. intracellularis, LI1035 was identified as the first putative effector that inhibits yeast growth. The LI1035-induced growth inhibition was rescued in two of the 14 mitogen-activated protein kinase (MAPK) yeast haploid deletion strains, suggesting that LI1035 interacts with the components of the MAPK pathway in yeast. Phosphorylation assays confirmed that LI1035 inhibits MAPK signaling cascades in yeast and mammalian cells. Actin staining assays revealed that LI1035 regulates actin organization in yeast and mammalian cells. Taken together, these results indicate that LI1035 alters MAPK pathway activity and regulates actin organization in the host. These findings may contribute to the understanding the pathogenesis of L. intracellularis and support the use of yeast as a heterologous system for the functional analysis of pathogen-specific gene products in the laboratory.


Assuntos
Actinas/metabolismo , Proteínas de Bactérias/metabolismo , Lawsonia (Bactéria)/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Transdução de Sinais , Animais , Proteínas de Bactérias/genética , Proliferação de Células , Interações entre Hospedeiro e Microrganismos , Lawsonia (Bactéria)/genética , Fosforilação , Saccharomyces cerevisiae/genética , Sorbitol/farmacologia , Suínos , Temperatura Ambiente
14.
Life Sci ; 232: 116637, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31288014

RESUMO

Keloid is characterized by overactive fibroblasts. Forkhead box M1 (FOXM1) is transcription factor that plays important roles in the progression of fibrosis. However, the role of FOXM1 in keloid has not been elucidated. In the present study, we examined the expression levels of FOXM1 in clinical keloid tissue specimens and primary keloid fibroblasts (KFs). The results showed that FOXM1 levels were significantly increased in both keloid tissues and KFs. To further investigate the biological functions of FOXM1, FOXM1 was knocked down in KFs by transfection with small interfering RNA targeting FOXM1 (si-FOXM1). Knockdown of FOXM1 inhibited transforming growth factor-ß1 (TGF-ß1)-induced cell proliferation and migration of KFs. Besides, the increased expressions of collagen (coll I), connective tissue growth factor (CTGF), and α-smooth muscle actin (α-SMA) in TGF-ß1-induced KFs were suppressed by si-FOXM1 transfection. Furthermore, TGF-ß1-induced increase in p-Smad2 and p-Smad3 expressions was attenuated by FOXM1 knockdown. These data indicated that knockdown of FOXM1 inhibited TGF-ß1-induced KFs activation and extracellular matrix (ECM) accumulation, which was attributed to the inhibition of TGF-ß1/Smad pathway.


Assuntos
Proteína Forkhead Box M1/deficiência , Queloide/metabolismo , Actinas/metabolismo , Adolescente , Adulto , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas , Colágeno/metabolismo , Colágeno Tipo I/metabolismo , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Feminino , Fibroblastos/metabolismo , Proteína Forkhead Box M1/genética , Proteína Forkhead Box M1/metabolismo , Técnicas de Silenciamento de Genes/métodos , Humanos , Queloide/genética , Masculino , Fosforilação , RNA Interferente Pequeno/genética , Transdução de Sinais , Proteína Smad2/antagonistas & inibidores , Proteína Smad2/metabolismo , Proteína Smad3/antagonistas & inibidores , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta1/antagonistas & inibidores , Fator de Crescimento Transformador beta1/metabolismo
15.
Pol J Microbiol ; 68(2): 217-224, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31250592

RESUMO

Campylobacter fetus is an important venereal pathogen of cattle that causes infertility and abortions. It is transmitted during mating, and it travels from the vagina to the uterus; therefore, an important cell type that interacts with C. fetus are endometrial epithelial cells. Several virulence factors have been identified in the genome of C. fetus, such as adhesins, secretion systems, and antiphagocytic layers, but their expression is unknown. The ability of C. fetus to invade human epithelial cells has been demonstrated, but the ability of this microorganism to infect bovine endometrial epithelial cells has not been demonstrated. Bovine endometrial epithelial cells were isolated and challenged with C. fetus. The presence of C. fetus inside the endometrial epithelial cells was confirmed by the confocal immunofluorescence. C. fetus was not internalized when actin polymerization was disturbed, suggesting cytoskeleton participation in an internalization mechanism. To evaluate the intracellular survival of C. fetus, a gentamicin protection assay was performed. Although C. fetus was able to invade epithelial cells, the results showed that it did not have the capacity to survive in the intracellular environment. This study reports for the first time, the ability of C. fetus to invade bovine endometrial epithelial cells, and actin participation in this phenomenon.Campylobacter fetus is an important venereal pathogen of cattle that causes infertility and abortions. It is transmitted during mating, and it travels from the vagina to the uterus; therefore, an important cell type that interacts with C. fetus are endometrial epithelial cells. Several virulence factors have been identified in the genome of C. fetus, such as adhesins, secretion systems, and antiphagocytic layers, but their expression is unknown. The ability of C. fetus to invade human epithelial cells has been demonstrated, but the ability of this microorganism to infect bovine endometrial epithelial cells has not been demonstrated. Bovine endometrial epithelial cells were isolated and challenged with C. fetus. The presence of C. fetus inside the endometrial epithelial cells was confirmed by the confocal immunofluorescence. C. fetus was not internalized when actin polymerization was disturbed, suggesting cytoskeleton participation in an internalization mechanism. To evaluate the intracellular survival of C. fetus, a gentamicin protection assay was performed. Although C. fetus was able to invade epithelial cells, the results showed that it did not have the capacity to survive in the intracellular environment. This study reports for the first time, the ability of C. fetus to invade bovine endometrial epithelial cells, and actin participation in this phenomenon.


Assuntos
Infecções por Campylobacter/microbiologia , Campylobacter fetus/fisiologia , Endocitose , Células Epiteliais/microbiologia , Actinas/metabolismo , Animais , Antibacterianos/farmacologia , Bovinos , Doenças dos Bovinos , Células Cultivadas , Gentamicinas/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Microscopia Confocal , Microscopia de Fluorescência , Modelos Biológicos
16.
Nat Commun ; 10(1): 2856, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31253774

RESUMO

Microfilaments (actin) and microtubules represent the extremes in eukaryotic cytoskeleton cross-sectional dimensions, raising the question of whether filament architectures are limited by protein fold. Here, we report the cryoelectron microscopy structure of a complex filament formed from 15 protofilaments of an actin-like protein. This actin-like ParM is encoded on the large pCBH Clostridium botulinum plasmid. In cross-section, the ~26 nm diameter filament comprises a central helical protofilament surrounded by intermediate and outer layers of six and eight twisted protofilaments, respectively. Alternating polarity of the layers allows for similar lateral contacts between each layer. This filament design is stiffer than the actin filament, and has likely been selected for during evolution to move large cargos. The comparable sizes of microtubule and pCBH ParM filaments indicate that larger filament architectures are not limited by the protomer fold. Instead, function appears to have been the evolutionary driving force to produce broad, complex filaments.


Assuntos
Actinas/metabolismo , Proteínas de Bactérias/metabolismo , Clostridium botulinum/metabolismo , Citoesqueleto/fisiologia , Citoesqueleto de Actina , Actinas/genética , Proteínas de Bactérias/genética , Microscopia Crioeletrônica , Regulação Bacteriana da Expressão Gênica/fisiologia , Modelos Moleculares , Conformação Proteica
17.
Life Sci ; 232: 116591, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31228513

RESUMO

AIMS: Calreticulin (CRT) is a multifunctional protein that protects endothelial cells by alleviating actin cytoskeleton injury, but the underlying mechanism remains unclear. CRT was recently identified as a novel acyltransferase; acetylation at the N-terminus of actin monomers strengthens actin polymerization. This study was undertaken to determine whether CRT protects human microvascular endothelial cells (HMECs) against microwave radiation through actin acetylation. MATERIALS AND METHODS: We prepared a eukaryotic-derived recombinant CRT and incubated the HMECs with it prior to microwave exposure. We then assessed cell injury and endothelial function, detected actin polymerization and acetylation after HMECs exposure to S-band high-power microwaves. Coimmunoprecipitation, pull-down, and ex vitro acetylation reaction were performed to determine whether actin is a novel substrate of CRT acyltransferase. Finally, we employed the mutant experiments to demonstrate the acetylation sites contributing to CRT acetyltransferase activity. KEY FINDINGS: Microwave radiation induced severe cell injury and endothelial contact dysfunction, reduced the polymerization of actin filaments, and destroyed the actin arrangement, ultimately reducing acetylated actin expression. CRT treatment upregulated actin acetylation levels, promoted polymerization, and facilitated thicker and longer F-actin stress fibre formation. Pre-incubation with CRT rescued microwave-induced cell injury, decreased actin acetylation, and rendered the actin cytoskeleton radiation-retardant. The level of acetyl-actin was positively correlated with actin polymerization. Actin was identified as a novel substrate of CRT, being acetylated mainly through the CRT P-domain at lys-206 and -207. SIGNIFICANCE: This work provides a better understanding of the underlying mechanism of CRT-induced cytoprotection, and suggests a novel therapeutic target for microwave radiation-related diseases with endothelial dysfunction.


Assuntos
Actinas/metabolismo , Calreticulina/farmacologia , Microvasos/efeitos dos fármacos , Acetilação/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Linhagem Celular , Citoproteção , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Humanos , Microvasos/efeitos da radiação , Micro-Ondas , Substâncias Protetoras , Processamento de Proteína Pós-Traducional , Transdução de Sinais
18.
Biochemistry (Mosc) ; 84(4): 358-369, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31228927

RESUMO

Cytoplasmic actin structures are essential components of the eukaryotic cytoskeleton. According to the classic concepts, actin structures perform contractile and motor functions, ensuring the possibility of cell shape changes during cell spreading, polarization, and movement both in vitro and in vivo, from the early embryogenesis stages and throughout the life of a multicellular organism. Intracellular organization of actin structures, their biochemical composition, and dynamic properties play a key role in the realization of specific cellular and tissue functions and vary in different cell types. This paper is a review of recent studies on the organization and properties of actin structures in endotheliocytes, interaction of these structures with other cytoskeletal components and elements involved in cell adhesion, as well as their role in the functional activity of endothelial cells.


Assuntos
Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Citoesqueleto de Actina/química , Actinas/química , Actinas/genética , Caderinas/química , Caderinas/metabolismo , Citosol/metabolismo , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Humanos , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/química , Microtúbulos/metabolismo
19.
PLoS Genet ; 15(6): e1008228, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31220078

RESUMO

Dendrite growth is constrained by a self-avoidance response that induces retraction but the downstream pathways that balance these opposing mechanisms are unknown. We have proposed that the diffusible cue UNC-6(Netrin) is captured by UNC-40(DCC) for a short-range interaction with UNC-5 to trigger self-avoidance in the C. elegans PVD neuron. Here we report that the actin-polymerizing proteins UNC-34(Ena/VASP), WSP-1(WASP), UNC-73(Trio), MIG-10(Lamellipodin) and the Arp2/3 complex effect dendrite retraction in the self-avoidance response mediated by UNC-6(Netrin). The paradoxical idea that actin polymerization results in shorter rather than longer dendrites is explained by our finding that NMY-1 (non-muscle myosin II) is necessary for retraction and could therefore mediate this effect in a contractile mechanism. Our results also show that dendrite length is determined by the antagonistic effects on the actin cytoskeleton of separate sets of effectors for retraction mediated by UNC-6(Netrin) versus outgrowth promoted by the DMA-1 receptor. Thus, our findings suggest that the dendrite length depends on an intrinsic mechanism that balances distinct modes of actin assembly for growth versus retraction.


Assuntos
Actinas/genética , Proteínas de Caenorhabditis elegans/genética , Células Dendríticas/metabolismo , Netrinas/genética , Neurônios/metabolismo , Citoesqueleto de Actina/genética , Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Actinas/metabolismo , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Membrana/genética , Cadeias Pesadas de Miosina/genética , Proteínas do Tecido Nervoso/genética , Miosina não Muscular Tipo IIB/genética
20.
Nat Cell Biol ; 21(7): 845-855, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31209295

RESUMO

RPEL proteins, which contain the G-actin-binding RPEL motif, coordinate cytoskeletal processes with actin dynamics. We show that the ArhGAP12- and ArhGAP32-family GTPase-activating proteins (GAPs) are RPEL proteins. We determine the structure of the ArhGAP12/G-actin complex, and show that G-actin contacts the RPEL motif and GAP domain sequences. G-actin inhibits ArhGAP12 GAP activity, and this requires the G-actin contacts identified in the structure. In B16 melanoma cells, ArhGAP12 suppresses basal Rac and Cdc42 activity, F-actin assembly, invadopodia formation and experimental metastasis. In this setting, ArhGAP12 mutants defective for G-actin binding exhibit more effective downregulation of Rac GTP loading following HGF stimulation and enhanced inhibition of Rac-dependent processes, including invadopodia formation. Potentiation or disruption of the G-actin/ArhGAP12 interaction, by treatment with the actin-binding drugs latrunculin B or cytochalasin D, has corresponding effects on Rac GTP loading. The interaction of G-actin with RPEL-family rhoGAPs thus provides a negative feedback loop that couples Rac activity to actin dynamics.


Assuntos
Actinas/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Proteína cdc42 de Ligação ao GTP/metabolismo , Actinas/efeitos dos fármacos , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Citocalasina D/farmacologia , Proteínas Ativadoras de GTPase/efeitos dos fármacos , Proteínas Ativadoras de GTPase/genética , Guanosina Trifosfato/metabolismo , Humanos , Camundongos , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Coelhos , Tiazolidinas/farmacologia , Proteína cdc42 de Ligação ao GTP/efeitos dos fármacos , Proteínas rac de Ligação ao GTP/metabolismo
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