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1.
Int J Mol Sci ; 23(13)2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35805929

RESUMO

Panose is a type of functional sugar with diverse bioactivities. The enzymatic conversion bioprocess to produce high purity panose with high efficiency has become increasingly important. Here, a new neopullulanase (NPase), Amy117 from B. pseudofirmus 703, was identified and characterized. Amy117 presented the optimal activity at pH 7.0 and 30 °C, its activity is over 40% at 10 °C and over 80% at 20 °C, which is cold-active. The enzyme cleaved α-1, 4-glycosidic linkages of pullulan to generate panose as the only hydrolysis product, and degraded cyclodextrins (CDs) and starch to glucose and maltose, with an apparent preference for CDs. Furthermore, Amy117 can produce 72.7 mg/mL panose with a conversion yield of 91% (w/w) based on 80 mg/mL pullulan. The sequence and structure analysis showed that the low proportion of Arg, high proportion of Asn and Gln, and high α-helix levels in Amy117 may contribute to its cold-active properties. Root mean square deviation (RMSD) analysis also showed that Amy117 is more flexible than two mesophilic homologues. Hence, we discovered a new high-efficiency panose-producing NPase, which so far achieves the highest panose production and would be an ideal candidate in the food industry.


Assuntos
Ciclodextrinas , Glicosídeo Hidrolases , Ciclodextrinas/metabolismo , Glucanos , Glicosídeo Hidrolases/metabolismo , Especificidade por Substrato
2.
J Exp Bot ; 71(10): 2956-2969, 2020 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-32064495

RESUMO

UDP-glucose epimerases (UGEs) are essential enzymes for catalysing the conversion of UDP-glucose (UDP-Glc) into UDP-galactose (UDP-Gal). Although UDP-Gal has been well studied as the substrate for the biosynthesis of carbohydrates, glycolipids, and glycoproteins, much remains unknown about the biological function of UGEs in plants. In this study, we selected a novel rice fragile culm 24 (Osfc24) mutant and identified it as a nonsense mutation of the FC24/OsUGE2 gene. The Osfc24 mutant shows a brittleness phenotype with significantly altered cell wall composition and disrupted orientation of the cellulose microfibrils. We found significantly reduced accumulation of arabinogalactan proteins in the cell walls of the mutant, which may consequently affect plant growth and cell wall deposition, and be responsible for the altered cellulose microfibril orientation. The mutant exhibits dwarfism and paler leaves with significantly decreased contents of galactolipids and chlorophyll, resulting in defects in plant photosynthesis. Based on our results, we propose a model for how OsUGE2 participates in two distinct metabolic pathways to co-modulate cellulose biosynthesis and cell wall assembly by dynamically providing UDP-Gal and UDP-Glc substrates.


Assuntos
Oryza , UDPglucose 4-Epimerase , Parede Celular/metabolismo , Glucose/metabolismo , Oryza/genética , Oryza/metabolismo , Fotossíntese , UDPglucose 4-Epimerase/genética , UDPglucose 4-Epimerase/metabolismo , Difosfato de Uridina/metabolismo
3.
Plant Mol Biol ; 101(4-5): 389-401, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31432304

RESUMO

KEY MESSAGE: Overexpression of cotton cellulose synthase like D3 (GhCSLD3) gene partially rescued growth defect of atcesa6 mutant with restored cell elongation and cell wall integrity mainly by enhancing primary cellulose production. Among cellulose synthase like (CSL) family proteins, CSLDs share the highest sequence similarity to cellulose synthase (CESA) proteins. Although CSLD proteins have been implicated to participate in the synthesis of carbohydrate-based polymers (cellulose, pectins and hemicelluloses), and therefore plant cell wall formation, the exact biochemical function of CSLD proteins remains controversial and the function of the remaining CSLD genes in other species have not been determined. In this study, we attempted to illustrate the function of CSLD proteins by overexpressing Arabidopsis AtCSLD2, -3, -5 and cotton GhCSLD3 genes in the atcesa6 mutant, which has a background that is defective for primary cell wall cellulose synthesis in Arabidopsis. We found that GhCSLD3 overexpression partially rescued the growth defect of the atcesa6 mutant during early vegetative growth. Despite the atceas6 mutant having significantly reduced cellulose contents, the defected cell walls and lower dry mass, GhCSLD3 overexpression largely restored cell wall integrity (CWI) and improved the biomass yield. Our result suggests that overexpression of the GhCSLD protein enhances primary cell wall synthesis and compensates for the loss of CESAs, which is required for cellulose production, therefore rescuing defects in cell elongation and CWI.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Gossypium/genética , Proteínas de Plantas/fisiologia , Arabidopsis/genética , Arabidopsis/metabolismo , Parede Celular/metabolismo , Celulose/biossíntese , Celulose/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo
4.
Plant Cell Physiol ; 59(6): 1144-1157, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29514326

RESUMO

Cellulose is the most characteristic component of plant cell walls, and plays a central role in plant mechanical strength and morphogenesis. Despite the fact that cellulose synthase (CesA) mutants exhibit a reduction in cellulose level, much remains unknown about their impacts on cell growth (elongation and division) and cell wall integrity that fundamentally determine plant growth. Here, we examined three major types of AtCesA mutants (rsw1, an AtCesA1 mutant; prc1-1 and cesa6, AtCesA6-null mutants; and IRX3, an AtCesA7 mutant) and transgenic mutants that overexpressed AtCesA genes in the background of AtCesA6-null mutants. We found that AtCesA6-null mutants showed a reduced cell elongation of young seedlings with little impact on cell division, which consequently affected cell wall integrity and biomass yield of mature plants. In comparison, rsw1 seedlings exhibited a strong defect in both cell elongation and division at restrictive temperature, whereas the IRX3 mutant showed normal seedling growth. Analyses of transgenic mutants indicated that primary wall AtCesA2, AtCesA3, AtCesA5 and AtCesA9 genes played a partial role in restoration of seedling growth. However, co-overexpression of AtCesA2 and AtCesA5 in AtCesA6-null mutants could greatly enhance cell division and fully restore wall integrity, leading to a significant increase in secondary wall thickness and biomass production in mature plants. Hence, this study has demonstrated distinct functions of AtCesA genes in plant cell growth and cell wall deposition for biomass production, which helps to expalin our recent finding that only three AtCesA6-like genes, rather than other AtCesA genes of the AtCesA family, could greatly enhance biomass production in transgenic Arabidopsis plants.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/enzimologia , Glucosiltransferases/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Biomassa , Divisão Celular , Crescimento Celular , Parede Celular/metabolismo , Celulose/metabolismo , Glucosiltransferases/metabolismo , Plântula/enzimologia , Plântula/genética , Plântula/crescimento & desenvolvimento
5.
Plant Biotechnol J ; 16(5): 976-988, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-28944540

RESUMO

Cellulose is an abundant biopolymer and a prominent constituent of plant cell walls. Cellulose is also a central component to plant morphogenesis and contributes the bulk of a plant's biomass. While cellulose synthase (CesA) genes were identified over two decades ago, genetic manipulation of this family to enhance cellulose production has remained difficult. In this study, we show that increasing the expression levels of the three primary cell wall AtCesA6-like genes (AtCesA2, AtCesA5, AtCesA6), but not AtCesA3, AtCesA9 or secondary cell wall AtCesA7, can promote the expression of major primary wall CesA genes to accelerate primary wall CesA complex (cellulose synthase complexes, CSCs) particle movement for acquiring long microfibrils and consequently increasing cellulose production in Arabidopsis transgenic lines, as compared with wild-type. The overexpression transgenic lines displayed changes in expression of genes related to cell growth and proliferation, perhaps explaining the enhanced growth of the transgenic seedlings. Notably, overexpression of the three AtCesA6-like genes also enhanced secondary cell wall deposition that led to improved mechanical strength and higher biomass production in transgenic mature plants. Hence, we propose that overexpression of certain AtCesA genes can provide a biotechnological approach to increase cellulose synthesis and biomass accumulation in transgenic plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Celulose/metabolismo , Glucosiltransferases/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Biomassa , Parede Celular/enzimologia , Expressão Gênica , Glucosiltransferases/genética , Plantas Geneticamente Modificadas , Plântula/enzimologia , Plântula/genética , Plântula/crescimento & desenvolvimento
6.
Plant Biotechnol J ; 16(1): 254-263, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28574641

RESUMO

Plant lodging resistance is an important integrative agronomic trait of grain yield and quality in crops. Although extensin proteins are tightly associated with plant cell growth and cell wall construction, little has yet been reported about their impacts on plant lodging resistance. In this study, we isolated a novel extensin-like (OsEXTL) gene in rice, and selected transgenic rice plants that expressed OsEXTL under driven with two distinct promoters. Despite different OsEXTL expression levels, two-promoter-driven OsEXTL-transgenic plants, compared to a rice cultivar and an empty vector, exhibited significantly reduced cell elongation in stem internodes, leading to relatively shorter plant heights by 7%-10%. Meanwhile, the OsEXTL-transgenic plants showed remarkably thickened secondary cell walls with higher cellulose levels in the mature plants, resulting in significantly increased detectable mechanical strength (extension and pushing forces) in the mature transgenic plants. Due to reduced plant height and increased plant mechanical strength, the OsEXTL-transgenic plants were detected with largely enhanced lodging resistances in 3 years field experiments, compared to those of the rice cultivar ZH11. In addition, despite relatively short plant heights, the OsEXTL-transgenic plants maintain normal grain yields and biomass production, owing to their increased cellulose levels and thickened cell walls. Hence, this study demonstrates a largely improved lodging resistance in the OsEXTL-transgenic rice plants, and provides insights into novel extensin functions in plant cell growth and development, cell wall network construction and wall structural remodelling.


Assuntos
Parede Celular/metabolismo , Oryza/metabolismo , Caules de Planta/metabolismo , Parede Celular/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Oryza/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Caules de Planta/fisiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo
7.
J Exp Bot ; 69(5): 1065-1080, 2018 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-29253184

RESUMO

CSLD3, a gene of the cellulose synthase-like D family, affects root hair elongation, but its interactions with ethylene signaling and phosphate-starvation are poorly understood. Here, we aim to understand the role of CSLD3 in the context of the ethylene signaling and phosphate starvation pathways in Arabidopsis plant growth. Therefore, we performed a comparative analysis of the csld3-1 mutant, CSLD3-overexpressing lines, and ethylene-response mutants, such as the constitutive ethylene-response mutant i-ctr1. We found that CSLD3 overexpression enhanced root and hypocotyl growth by increasing cell elongation, and that the root growth was highly sensitive to ethylene treatment (1 µM ACC), in particular under phosphate starvation. However, the CSLD3-mediated hypocotyl elongation occurred independently of the ethylene signaling pathway. Notably, the typical induction of root hair and root elongation by ethylene and phosphate-starvation was completely abolished in the csld3-1 mutant. Furthermore, i-ctr1 csld3-1 double-mutants were hairless like the csld3-1 parent, confirming that CSLD3 acts downstream of the ethylene signaling pathway during root growth. Moreover, the CSLD3 levels positively correlated with cellulose levels, indicating a role of CSLD3 in cellulose synthesis, which may explain the observed growth effects. Our results establish how CSLD3 works in the context of the ethylene signaling and phosphate-starvation pathways during root hair growth, cell elongation, and cell wall biosynthesis.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Etilenos/metabolismo , Gossypium/genética , Fosfatos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Crescimento Celular , Gossypium/metabolismo , Raízes de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Transdução de Sinais
8.
Chemistry ; 24(39): 9869-9876, 2018 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-29766584

RESUMO

Aflatoxin B1 (AFB1 ), one of the most toxic mycotoxins, is classified as a group I carcinogen and ubiquitous in various foods and agriproducts. Thus, accurate and sensitive determination of AFB1 is of great significance to meet the criteria of food safety. Direct detection of AFB1 is difficult by monoclonal antibody (mAb) with large molecular size (≈150 kD) since the target is too small to produce a detectable signal change. Herein, by combining the electrochemical properties of nanomaterials and the advantages of nanobodies, we developed a direct, highly selective and sensitive electrochemical immunosensor for small molecule detection. The proposed immunosensor had a wide calibration range of 0.01 to 100 ng mL-1 and a low detection limit of 3.3 pg mL-1 (S/N=3). Compared with the immunosensor prepared with mAb which was applied in the typical indirect immunoassay, the immunosensor in this work possessed two orders of magnitudes wider linear range and 10-fold more sensitivity. The as-obtained immunosensor was further successfully applied for sensing AFB1 in real samples. This proposed assay would provide a simple, highly sensitive and selective approach for the direct immunoassay of small molecule AFB1 , and is extendable to the development of direct immunosensing systems for other small molecules detection by coupling nanocarbon and nanobody.


Assuntos
Aflatoxina B1/química , Anticorpos Monoclonais/química , Imunoensaio , Técnicas Biossensoriais , Técnicas Eletroquímicas , Limite de Detecção
9.
Tumour Biol ; 37(1): 521-30, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26227219

RESUMO

This study aimed to identify carcinogenic potential-related molecular mechanisms in cancer stem cells (CSCs) in lung cancer. CD133(+) and CD133(-) subpopulations were sorted from A549 cells using magnetic-activated cell sorting. The abilities to form sphere and clone, proliferate, migrate, and invade were compared between CD133(+) and CD133(-) cells, as well as drug sensitivity. Thereafter, microRNA (miRNA) profiles were performed to identify differentially expressed miRNAs between CD133(+) and CD133(-) subpopulation. Following, bioinformatic methods were used to predict target genes for differentially expressed miRNAs and perform enrichment analysis. Furthermore, the mammalian target of rapamycin (mTOR) signaling pathways and CSC property-associated signaling pathways were explored and visualized in regulatory network among competitive endogenous RNA (ceRNA), miRNA, and target gene. CD133(+) subpopulation showed greater oncogenic potential than CD133(-) subpopulation. In all, 14 differentially expressed miRNAs were obtained and enriched in 119 pathways, including five upregulated (hsa-miR-23b-3p, -23a-3p, -15b-5p, -24-3p, and -4734) and nine downregulated (hsa-miR-1246, -30b-5p, -5096, -6510-5p, has-miR-7110-5p, -7641, -3197, -7108-5p, and -6791-5p). For mTOR signaling pathway, eight differential miRNAs (hsa-miR-23b-3p, -23a-3p, -15b-5p, -24-3p, -4734, -1246, -7641, and -3197) and 39 target genes (e.g., AKT1, AKT2, PIK3CB, PIK3CG, PIK3R1, PIK3CA, and PIK3CD) were involved, as well as some ceRNAs. Besides, for CSC property-related signaling pathways, six miRNAs (hsa-miR-1246, -15b-5p, -30b-5p, -3197, -4734, and -7110-5p) were dramatically enriched in Hedgehog, Notch, and Wnt signaling pathways via regulating 108 target genes (e.g., DVL1, DVL3, WNT3A, and WNT5A). The mTOR and CSC property-associated signaling pathways may be important oncogenic molecular mechanisms in CD133(+) A549 cells.


Assuntos
Antígeno AC133/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/metabolismo , MicroRNAs/metabolismo , Células A549 , Antineoplásicos/química , Carcinogênese , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Separação Celular , Biologia Computacional , Perfilação da Expressão Gênica , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias/metabolismo , Células-Tronco Neoplásicas , Transdução de Sinais
10.
J Plant Res ; 129(5): 899-907, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27229891

RESUMO

Despite the paraquat-resistant mutants that have been reported in plants, this study identified a novel A. thaliana mutant (pqr2) from an XVE inducible activation library based on its resistance to 2 µM paraquat. The pqr2 mutant exhibited a termination mutation in the exon of AT1G31830/PAR1/PQR2, encoded a polyamine uptake transporter AtPUT2/PAR1/PQR2. The PQR2 mutation could largely reduce superoxide accumulation and cell death in the pqr2 plants under paraquat treatment. Moreover, compared with wild type, the pqr2 mutant exhibited much reduced tolerance to putrescine, a classic polyamine compound, which confirmed that PQR2 encoded a defective polyamine transporter. Notably, co-treated with ABA and paraquat, both pqr2 mutant and wild type exhibited a lethal phenotype from seed germination, but the wild type like pqr2 mutant, could remain paraquat-resistance while co-treated with high dosage of Na2WO4, an ABA synthesis inhibitor. Gene expression analysis suggested that ABA signaling should widely regulate paraquat-responsive genes distinctively in wild type and pqr2 mutant. Hence, this study has for the first time reported about ABA negative effect on paraquat-resistance in A. thaliana, providing insight into the ABA signaling involved in the oxidative stress responses induced by paraquat in plants.


Assuntos
Ácido Abscísico/farmacologia , Proteínas de Arabidopsis/genética , Arabidopsis/genética , Resistência a Herbicidas , Proteínas de Membrana Transportadoras/genética , Mutação/genética , Paraquat/toxicidade , Poliaminas/metabolismo , Adaptação Fisiológica/efeitos dos fármacos , Sequência de Aminoácidos , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas de Membrana Transportadoras/química , Proteínas de Membrana Transportadoras/metabolismo , Fenótipo
11.
Zhonghua Zhong Liu Za Zhi ; 37(10): 736-40, 2015 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-26813591

RESUMO

OBJECTIVE: To fabricate an innovative scaffold for lung cancer cell culture and establish a three-dimensional lung cancer model in vitro, and to reveal the differences in biological functions of lung cancer cells under the two-dimensional and three-dimensional culture conditions. METHODS: We chose agarose and alginate as the scaffold materials, and 3D printing technique was applied to construct cell culture scaffold. 95D cells were co-cultured with this scaffold. The differences of cell morphology, proliferation ability, protein expression, etc. in the cells cultured under 2D and 3D cultural conditions were evaluated by light microscopy using HE staining, MTT assay, scanning electron microscopy, and Western blot analysis. RESULTS: Cells cultured in 2D wells displayed a spindle and polygonal morphology, whereas those grown in the 3D culture aggregated into spheroids, which invaded, migrated and disseminated into the surrounding scaffold. MTT assay showed that the proliferation rates of the 3D-cultured cells for 2-6 days were significantly lower than, but those cultured for 8-9 days were significantly higher than that of the 2D-cultured cells, indicating that proliferative activity of the cells grown in 2D cultures for 8-9 days was inhibited. In contrast, cells grown on 3D scaffolds still maintained a higher proliferation. The Western blot assay showed that the expression of Cdc42, p53, mTOR were significantly down-regulated in 3D scaffold-cultured group (0.529±0.103, 0.820±0.038 vs. 1.967±0.066), compared with that of the 2D-cultured group (3.063±0.139, 1.738±0.122 vs. 2.472±0.151) (P<0.05 for all), while the expression of MMP-2 was up-regulated in the 3D-cultured cells (1.110±0.029), significantly higher than that of the 2D-cultured cells (0.017±0.001) (P<0.05). CONCLUSIONS: The cell morphology, proliferation and associated protein expression of lung cancer cells in 3D-culture systems are distinctively different as compared to those of the 2D-cultural cells. 3D-bioprinted agarose-alginate scaffold can better mimic the growth microenvironment of lung cancer in vivo and may provide a promising model for lung cancer research in vitro.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Técnicas de Cultura de Células , Neoplasias Pulmonares/patologia , Impressão Tridimensional , Alicerces Teciduais , Alginatos , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/fisiopatologia , Movimento Celular , Proliferação de Células , Células Cultivadas , Técnicas de Cocultura , Ácido Glucurônico , Ácidos Hexurônicos , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/fisiopatologia , Invasividade Neoplásica , Proteínas de Neoplasias/metabolismo , Sefarose , Esferoides Celulares/patologia , Fatores de Tempo , Microambiente Tumoral
12.
Carbohydr Polym ; 329: 121787, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38286554

RESUMO

The stem support for fresh-cut flowers exerts a profound influence on the display of their blossoms. During vase insertion, bending stems significantly affect the ornamental value, but much remains unclear about the underlying reasons. In this study, six pairs of ornamental plants were screened for the contrast of bending and straight stems. The bending stems have weakened mechanical force and biomass recalcitrance compared with the straight ones. Meanwhile, cells in the bending stems became more loosely packed, along with a decrease in cell wall thickness and cellulose levels. Furthermore, wall properties characterizations show bending stems have decreased lignocellulosic CrI and cellulose DP, and enhanced the branching ratio of hemicellulose which is trapped in the cellulose. Given the distinct cell wall factors in different species, all data are grouped in standardized to eliminate the variations among plant species. The principal composition analysis and correlation analysis of the processed dataset strongly suggest that cellulose association factors determine the stem mechanical force and recalcitrance. Based on our results, we propose a model for how branches of confined hemicellulose interacted with cellulose to modulate stem strength support for the straight or bending phenotype in cut flowers.


Assuntos
Celulose , Xilanos , Celulose/análise , Xilanos/análise , Plantas , Parede Celular/química , Flores , Caules de Planta
13.
Nat Commun ; 14(1): 1100, 2023 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-36841862

RESUMO

Plant cellulose microfibrils are increasingly employed to produce functional nanofibers and nanocrystals for biomaterials, but their catalytic formation and conversion mechanisms remain elusive. Here, we characterize length-reduced cellulose nanofibers assembly in situ accounting for the high density of amorphous cellulose regions in the natural rice fragile culm 16 (Osfc16) mutant defective in cellulose biosynthesis using both classic and advanced atomic force microscopy (AFM) techniques equipped with a single-molecular recognition system. By employing individual types of cellulases, we observe efficient enzymatic catalysis modes in the mutant, due to amorphous and inner-broken cellulose chains elevated as breakpoints for initiating and completing cellulose hydrolyses into higher-yield fermentable sugars. Furthermore, effective chemical catalysis mode is examined in vitro for cellulose nanofibers conversion into nanocrystals with reduced dimensions. Our study addresses how plant cellulose substrates are digestible and convertible, revealing a strategy for precise engineering of cellulose substrates toward cost-effective biofuels and high-quality bioproducts.


Assuntos
Celulose , Nanofibras , Celulose/química , Nanofibras/química , Microscopia de Força Atômica , Açúcares , Parede Celular
14.
Mol Cell Biochem ; 359(1-2): 389-98, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21874542

RESUMO

We previously reported that curcumin inhibited lung cancer A549 cells growth and promoted cell apoptosis in vitro. In this study, we further examined the apoptosis-related parameters, including lysosomal damage and cathepsin activation, in A549 cells exposed to curcumin. We found that curcumin caused lysosomal membrane permeabilization (LMP) and cytosolic relocation of cathepsin B (cath B) and cathepsin D (cath D). However, only Z-FA-fmk (a cath B inhibitor) but not pepstatin A (a cath D inhibitor) inhibited curcumin-induced cell apoptosis, mitochondrial membrane potential loss, and cytochrome c release. The antioxidant N-acetylcysteine and glutathione attenuated LMP, suggesting that lysosomal destabilization was dependent on the elevation of reactive oxygen species and which precedes mitochondrial dysfunction. These findings indicated a novel pathway for curcumin regulation of ROS-lysosomal-mitochondrial pathway and provided the key mechanism of regulation of LMP in cell apoptosis, which may be exploited for cancer treatment.


Assuntos
Apoptose/efeitos dos fármacos , Curcumina/farmacologia , Membranas Intracelulares/efeitos dos fármacos , Neoplasias Pulmonares/patologia , Lisossomos/ultraestrutura , Antineoplásicos , Catepsina B/metabolismo , Catepsina D/metabolismo , Linhagem Celular Tumoral , Curcumina/uso terapêutico , Citocromos c , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Permeabilidade/efeitos dos fármacos , Espécies Reativas de Oxigênio
15.
Zhonghua Zhong Liu Za Zhi ; 34(1): 21-5, 2012 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-22490850

RESUMO

OBJECTIVE: To investigate the relationship between p16 expression and cell proliferation and prognosis in gastric cancer patients. METHODS: Gastric cancer cell lines SGC-7901, MKN45, MKN28, human embryonic kidney cell line HEK293, human fibroblast cell line MRC-5, and surgical specimens of gastric carcinoma and adjacent normal gastric mucosa from 65 patients were included in this study. RT-PCR, MTT and FCM assays were used to detect p16 expression in gastric cancer cell lines and surgical specimens of gastric cancer. MTT assay was used to determine cancer cell viability and FCM to detect cell cycle. Kaplan-Meier survival curve and Log-Rank statistics were used to analyze the relationship between p16 expression and survival of petients with gastric cancer. RESULTS: Gastric cancer cell lines were mostly negative for p16 expression, and p16 was re-expressed after the cells transfected with p16 gene by adenovirus AdCMV-p16. p16 re-expression resulted in the decrease of cancer cell viability and cancer cell cycle arrest with increased G(1) phase and decreased S phase. p16 expression in cancer specimens was 32.3% (21/65), significantly lower than the 81.5% (53/65) in normal mucosa (χ(2) = 32.124, P < 0.001). The disease-free survival was significantly shorter in p16-negative patients than that in p16-positive patients (P < 0.01), but not the overall survival (P > 0.05). p16 expression was significantly correlated with differentiation and lymph node metastasis, but not significantly correlated with sex, age, tumor size or invasion depth of the gastric cancer. CONCLUSIONS: p16 gene is important for cancer cell proliferation. The inactivation gives cancer cells a high activity for proliferation and metastasis, and then influences the disease-free survival of gastric cancer patients.


Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Genes p16 , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Adenoviridae/genética , Adulto , Idoso , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Inibidor p16 de Quinase Dependente de Ciclina/genética , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , RNA Mensageiro/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Taxa de Sobrevida , Transfecção
16.
Zhonghua Zhong Liu Za Zhi ; 34(6): 436-40, 2012 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-22967445

RESUMO

OBJECTIVE: To explore the expression of ezrin protein in human non-small cell lung cancer (NSCLC) tissues and lung cancer cell lines, and the association between the expression of ezrin protein and the expression of E-cadherin and CD44V6 proteins. METHODS: The expression of ezrin protein and mRNA in lung cancer cell lines was detected by RT-PCR and Western blotting. Ezrin, E-cadherin and CD44V6 were detected by immunohistochemical SP staining in tumor tissues from 150 lung cancer cases and in adjacent normal lung tissues from 30 patients. Furthermore, the expression of ezrin in 30 freshly-taken NSCLC tissues was also detected by Western blot. RESULTS: The expression of ezrin protein and mRNA was up-regulated in highly metastatic human lung cancer. The positive rate of ezrin, E-cadherin and CD44V6 expression in the lung cancer was 61.3%, 54.0% and 58.7%, respectively. The up-regulation of ezrin expression was significantly correlated with lymph node metastasis, but not correlated with age, sex, tumor size, histological type, clinical TNM system and pathological grade. Western blot analysis showed that the level of ezrin in the NSCLC tissues was significantly higher than that in the normal tissues (t = 5.013, P < 0.01). Survival analysis showed that the 5-year survival rate of patients with negative ezrin expression was 29.3%, significantly higher than that of patients with positive ezrin expression (15.2%, χ(2) = 4.128, P = 0.042). Multivariate Cox regression analysis showed that ezrin expression (RR = 3.012, P = 0.047) and lymph node metastasis (RR = 4.827, P = 0.035) were significantly independent prognostic factors for patients with lung cancer. Furthermore, a negative correlation was observed between the expressions of ezrin and E-cadherin in lung cancer, and a positive correlation between the expressions of ezrin and CD44V6 in lung cancer. CONCLUSIONS: Ezrin, E-cadherin and CD44V6 play an important role in the regulation of growth and meastasis of lung cancer. Combined detection of ezrin, E-cadherin and CD44V6 expression is helpful in evaluating the metastasis and prognosis of non-small cell lung cancer.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Proteínas do Citoesqueleto/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Adulto , Idoso , Antígenos CD , Caderinas/metabolismo , Linhagem Celular Tumoral , Proteínas do Citoesqueleto/genética , Feminino , Humanos , Receptores de Hialuronatos/metabolismo , Metástase Linfática , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Taxa de Sobrevida , Regulação para Cima
17.
J Cardiothorac Surg ; 16(1): 271, 2021 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-34565415

RESUMO

BACKGROUND: We investigated single-port video-assisted thoracoscopic surgery (VATS) combined with a postoperative non-indwelling drain in enhanced recovery after surgery (ERAS). METHODS: The clinical data of 127 patients who underwent double- and single-port VATS from January 2018 to December 2019 were analyzed retrospectively. The groups constituted 71 cases undergoing double-port and 56 cases undergoing single-port VATS (30 cases in the indwelling drain group and 26 cases in the non-indwelling drain group). The incidence of postoperative complications, pain scores, and postoperative hospital stay were compared between the two groups. RESULTS: Compared with the double-port group, the single-port group had shorter postoperative hospital stays and lower pain scores on the first and third postoperative days (P < 0.05). Pain scores on the first and third days were lower in the single-port non-indwelling drain group than in the single-port indwelling drain group (P < 0.05), and the postoperative hospitalization time was significantly shorter in the single-port group (P < 0.05). However, there was no significant difference between the two groups for operation time, incidence of complications, and pain scores 1 month after operation (P > 0.05). CONCLUSIONS: The combination of single-port VATS with a non-indwelling drain can relieve postoperative pain, help patients recover quickly, and is in accordance with ERAS.


Assuntos
Recuperação Pós-Cirúrgica Melhorada , Cirurgia Torácica Vídeoassistida , Drenagem , Humanos , Dor Pós-Operatória/epidemiologia , Dor Pós-Operatória/etiologia , Estudos Retrospectivos
18.
Front Plant Sci ; 12: 663536, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34489988

RESUMO

The plant mediator is a highly conserved protein complex that interacts with transcription factors (TFs) and RNA polymerase II (RNAP II) to relay regulatory information during transcription. Plant immune response is one of the biological processes that is orchestrated by this regulatory mechanism. Brassica napus, an important oil crop, is severely attacked by a devastating disease Sclerotinia stem rot. Here, we explored broad-spectrum disease resistant roles of B. napus mediator subunit 16 (BnMED16) and its host defense mechanism against fugal pathogen Sclerotinia sclerotiorum. We found that BnMED16 expression was significantly increased by S. sclerotiorum infection, and its homologous overexpression resulted in rapid and comprehensive defense responses from the beginning to the end. This affected signal transduction with multiple channels including pathogen recognition, intracellular Ca2+ concentration, reactive oxygen species (ROS) accumulation and clearance, and activation of mitogen-activated protein kinase (MAPK) signaling cascades initially. Subsequently, pathogen-/defense-related genes and hormone-responsive pathways were highly activated, which resulted in enhanced cell wall and secretion of defense proteases. Furthermore, the biochemical analysis showed that BnMED16 interacts with BnMED25 and BnWRKY33. Additionally, BnMED25 also interacts with TFs BnMYC2, BnCOI1, and BnEIN3 of the JA/ET signal transduction pathway. Taken together, we proposed a hypothetical model that BnMED16 confers S. sclerotiorum resistance by enhancing BnMED25-mediated JA/ET defense pathways and BnWRKY33-activated defense signaling in B. napus. The BnMED16 overexpressing lines with enhanced broad-spectrum disease resistance could be useful for breeding Sclerotinia-resistant oilseed rape varieties, as well as serving as basis for further strategy development in resistance breeding.

19.
BMC Plant Biol ; 10: 282, 2010 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-21167079

RESUMO

BACKGROUND: The cellulose synthase and cellulose synthase-like gene superfamily (CESA/CSL) is proposed to encode enzymes for cellulose and non-cellulosic matrix polysaccharide synthesis in plants. Although the rice (Oryza sativa L.) genome has been sequenced for a few years, the global expression profiling patterns and functions of the OsCESA/CSL superfamily remain largely unknown. RESULTS: A total of 45 identified members of OsCESA/CSL were classified into two clusters based on phylogeny and motif constitution. Duplication events contributed largely to the expansion of this superfamily, with Cluster I and II mainly attributed to tandem and segmental duplication, respectively. With microarray data of 33 tissue samples covering the entire life cycle of rice, fairly high OsCESA gene expression and rather variable OsCSL expression were observed. While some members from each CSL family (A1, C9, D2, E1, F6 and H1) were expressed in all tissues examined, many of OsCSL genes were expressed in specific tissues (stamen and radicles). The expression pattern of OsCESA/CSL and OsBC1L which extensively co-expressed with OsCESA/CSL can be divided into three major groups with ten subgroups, each showing a distinct co-expression in tissues representing typically distinct cell wall constitutions. In particular, OsCESA1, -3 & -8 and OsCESA4, -7 & -9 were strongly co-expressed in tissues typical of primary and secondary cell walls, suggesting that they form as a cellulose synthase complex; these results are similar to the findings in Arabidopsis. OsCESA5/OsCESA6 is likely partially redundant with OsCESA3 for OsCESA complex organization in the specific tissues (plumule and radicle). Moreover, the phylogenetic comparison in rice, Arabidopsis and other species can provide clues for the prediction of orthologous gene expression patterns. CONCLUSIONS: The study characterized the CESA/CSL of rice using an integrated approach comprised of phylogeny, transcriptional profiling and co-expression analyses. These investigations revealed very useful clues on the major roles of CESA/CSL, their potentially functional complement and their associations for appropriate cell wall synthesis in higher plants.


Assuntos
Perfilação da Expressão Gênica , Glucosiltransferases/genética , Oryza/genética , Proteínas de Plantas/genética , Sequência de Aminoácidos , Análise por Conglomerados , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Glucosiltransferases/classificação , Dados de Sequência Molecular , Família Multigênica , Análise de Sequência com Séries de Oligonucleotídeos , Filogenia , Proteínas de Plantas/classificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos
20.
Dig Dis Sci ; 54(7): 1425-31, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19034663

RESUMO

Replication-competent adenovirus (RCAd) constitutes an alternative in cancer therapy. For obtaining advanced RCAd generations with high oncolytic capability and a good safety profile, we constructed an E2F promoter-regulated RCAd carrying p16 gene, AdE2F-p16, in which the E1a gene was controlled by the E2F promoter. The experimental data showed that the E2F promoter endowed AdE2F-p16 with high specificity in cancer cells. While rarely replicating in normal cells, AdE2F-p16 could replicate in p16-deficient cancer cells, with 2,937- to 160,000-fold increased replicative capability in different cancer cell lines. AdE2F-p16 expressed p16 within cancer cells and led to potent antitumor efficacy in gastric cancer xenografts in nude mice, with a tumor inhibition rate of 59.14%. Due to the combined effects of cancer cell apoptosis induced by p16 expression and oncolysis by virus replication, the E2F promoter-regulated, p16-armed RCAd provides a promising strategy for cancer gene therapy.


Assuntos
Fatores de Transcrição E2F/fisiologia , Genes p16/fisiologia , Terapia Viral Oncolítica/métodos , Neoplasias Gástricas/genética , Replicação Viral/genética , Adenoviridae/fisiologia , Animais , Apoptose/genética , Ciclo Celular/fisiologia , Linhagem Celular Tumoral , Proteínas de Ligação a DNA , Regulação Neoplásica da Expressão Gênica/fisiologia , Vetores Genéticos , Humanos , Luciferases/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Transdução de Sinais/fisiologia , Neoplasias Gástricas/virologia , Ensaios Antitumorais Modelo de Xenoenxerto
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