Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
BMC Plant Biol ; 19(1): 283, 2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31248369

RESUMO

BACKGROUND: Metal homeostasis is critical for plant growth, development and adaptation to environmental stresses and largely governed by a variety of metal transporters. The plant ZIP (Zn-regulated transporter, Iron-regulated transporter-like Protein) family proteins belong to the integral membrane transporters responsible for uptake and allocation of essential and non-essential metals. However, whether the ZIP family members mediate metal efflux and its regulatory mechanism remains unknown. RESULTS: In this report, we provided evidence that OsZIP1 is a metal-detoxified transporter through preventing excess Zn, Cu and Cd accumulation in rice. OsZIP1 is abundantly expressed in roots throughout the life span and sufficiently induced by excess Zn, Cu and Cd but not by Mn and Fe at transcriptional and translational levels. Expression of OsZIP-GFP fusion in rice protoplasts and tobacco leaves shows that OsZIP1 resides in the endoplasmic reticulum (ER) and plasma membrane (PM). The yeast (Saccharomyces cerevisiae) complementation test shows that expression of OsZIP1 reduced Zn accumulation. Transgenic rice overexpressing OsZIP1 grew better under excess metal stress but accumulated less of the metals in plants. In contrast, both oszip1 mutant and RNA interference (RNAi) lines accumulated more metal in roots and contributed to metal sensitive phenotypes. These results suggest OsZIP1 is able to function as a metal exporter in rice when Zn, Cu and Cd are excess in environment. We further identified the DNA methylation of histone H3K9me2 of OsZIP1 and found that OsZIP1 locus, whose transcribed regions imbed a 242 bp sequence, is demethylated, suggesting that epigenetic modification is likely associated with OsZIP1 function under Cd stress. CONCLUSION: OsZIP1 is a transporter that is required for detoxification of excess Zn, Cu and Cd in rice.


Assuntos
Cádmio/metabolismo , Proteínas de Transporte de Cátions/genética , Cobre/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oryza/genética , Proteínas de Plantas/genética , Zinco/metabolismo , Transporte Biológico/efeitos dos fármacos , Proteínas de Transporte de Cátions/química , Proteínas de Transporte de Cátions/metabolismo , Oryza/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Estresse Fisiológico
2.
Zhongguo Gu Shang ; 32(4): 377-382, 2019 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-31027418

RESUMO

As a common soft tissue disease, the mechanism of tendinopathy has not been clarified and is lack of effective treatment method. Change of tissue fibrosis is the one of the main pathological features. Transforming growth factor beta 1 (TGF-ß1), which is one of the important factor, participated in fibrosis. Inconsonant expressions of TGF-ß1 could be found in tendinopathy. The studies are still controversial, but the vast majority of studies had showed that TGF-ß1 was abnormal, and it is given priority to increase, which means that TGF-ß1 plays an important role in the process of tendinopathy. In the process of tendon injuries and repairs, the time of TGF-ß1 increasing is inconsistent. The time for TGF-ß1 plays a significant role has not been determined. TGF-ß1 has abnormal expressions in both tendinopathy and tendon repairs, which are two opposite processes. Thus, it may not be a one-way adjustment factor, but has a pleiotropic. Recent studies showed that TGF-ß1 was considered as binding to receptor and transferring signal into the cell. Now there are three different receptors are found. The classical pathway of TGF-ß1 in intracellular signal transduction is mainly through activation of Smad pathway. In the same time, there are also some non-classical pathways. TGF-ß1 could break balance of extracellular matrix, which may be a reason to cause tendinopathy. But the regulations of TGF-ß1 on the extracellular matrix are complex and diverse, further studies are required. Existing researches showed that the performance of treatments on tendinopathy is unsatisfied by blocking TGF-ß1 downstream pathway. Therefore, it is a good way to study the upstream mechanism of produce TGF-ß1. It may be an effective method to find new targets to inhibit the development of tendinopathy better by finding the original source of TGF-ß1.


Assuntos
Tendinopatia , Fibrose , Humanos , Transdução de Sinais , Fator de Crescimento Transformador beta1
3.
Ecotoxicol Environ Saf ; 175: 8-18, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-30878662

RESUMO

HPP (heavy metal associated plant protein) and HIPP (heavy metal associated isoprenylated plant protein) are a group of metal-binding metallochaperones playing crucial roles in metal homeostasis and detoxification. Up to now, only few of them have been functionally identified in plants. Here, we identified 54 HPP and HIPP genes in rice genome. Analysis of the transcriptome datasets of the rice genome exposed to cadmium (Cd) revealed 17 HPP/HIPP genes differentially expressed, with 11 being upregulated (>2 fold change, p < 0.05). Comprehensive analysis of transcripts by qRT-PCR showed that both types of genes displayed diverse expression pattern in rice under excess manganese (Mn), copper (Cu) and Cd stress. Multiple genomic analyses of HPPs/HIPPs including phylogenesis, conserved domains and motifs, genomic arrangement and genomic and tandem duplication were performed. To identify the role of the genes, OsHIPP16, OsHIPP34 and OsHIPP60 were randomly selected to express in yeast (Saccharomyces cerevisiae) mutants pmrl, cup2, ycf1 and zrc1, exhibiting sensitivity to Mn, Cu, Cd and Zn toxicity, respectively. Complementation test showed that the transformed cells accumulated more metals in the cells, but their growth status was improved. To confirm the functional role, two mutant oshipp42 lines defective in OsHIPP42 expression were identified under metal stress. Under normal condition, no difference of growth between the oshipp42 mutant and wild-type plants was observed. Upon excess Cu, Zn, Cd and Mn, the oshipp42 lines grew weaker than the wild-type. Our work provided a novel source of heavy metal-binding genes in rice that can be potentially used to develop engineered plants for phytoremediation in heavy metal-contaminated soils.


Assuntos
Poluentes Ambientais/toxicidade , Genes de Plantas , Metais Pesados/toxicidade , Oryza/efeitos dos fármacos , Proteínas de Plantas/genética , Poluentes Ambientais/metabolismo , Estudo de Associação Genômica Ampla , Metais Pesados/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Filogenia , Prenilação de Proteína , Regulação para Cima
4.
J Bacteriol ; 200(13)2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29686136

RESUMO

The GntR family regulator DasR controls the transcription of genes involved in chitin and N-acetylglucosamine (GlcNAc) metabolism in actinobacteria. GlcNAc is catabolized to ammonia, fructose-6-phosphate (Fru-6P), and acetate, which are nitrogen and carbon sources. In this work, a DasR-responsive element (dre) was observed in the upstream region of acsA1 in Saccharopolyspora erythraea This gene encodes acetyl coenzyme A (acetyl-CoA) synthetase (Acs), an enzyme that catalyzes the conversion of acetate into acetyl-CoA. We found that DasR repressed the transcription of acsA1 in response to carbon availability, especially with GlcNAc. Growth inhibition was observed in a dasR-deleted mutant (ΔdasR) in the presence of GlcNAc in minimal medium containing 10 mM acetate, a condition under which Acs activity is critical to growth. These results demonstrate that DasR controls acetate assimilation by directly repressing the transcription of the acsA1 gene and performs regulatory roles in the production of intracellular acetyl-CoA in response to GlcNAc.IMPORTANCE Our work has identified the DasR GlcNAc-sensing regulator that represses the generation of acetyl-CoA by controlling the expression of acetyl-CoA synthetase, an enzyme responsible for acetate assimilation in S. erythraea The finding provides the first insights into the importance of DasR in the regulation of acetate metabolism, which encompasses the regulatory network between nitrogen and carbon metabolism in actinobacteria, in response to environmental changes.

5.
Curr Pharm Biotechnol ; 17(13): 1117-1125, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27587021

RESUMO

Physalis pubescens L. (P. pubescens) is an edible plant used in folk medicine in China. There is traditional, but not scientific, evidence for the anti-tumour effects of P. pubescens. This study aimed to identify whether, or not, antioxidants rich in phenols and flavonoids from fruits and calyxes of P. pubescens can be the candidates for further development of an anti-hepatoma fraction, and if such biological effects coupled with reactive oxygen species (ROS) changes, can provide a direction for subsequent biological action. The effects of calyx-origin (or fruit-origin) total phenol and flavonoid (CTPF or FTPF) from P. pubescens on Malhavu cell viability were evaluated by using a counting-kit-8 (CCK-8) method. Morphological characterisation of cells was undertaken and the structures were photographed (200 × magnification) using Hoechst 3348 staining after exposure to different concentrations of CTPF or FTPF. Induced-apoptosis activity was determined using flow cytometry (FC) after Annexin VFITC/ PI staining. The corresponding ROS changes in Malhavu cells were observed and quantified by the uploading of 2', 7'-dichlorofluorescin diacetate (DCFH-DA). Anti-oxidation was evaluated by a cellular oxidation-stress model and chemical assessments for DPPH, hydroxyl radial, super-oxide radicals, and reducing power. Result shows that CTPF led to significant anti-proliferation in a time- and dosedependent manner. However, FTPF promoted cell viability at 100-1000 µg/mL with a dose-response manner in 24 h. With the extension of exposure time to 48 h, the cell viability did not increase with the growth of FTPF. Morphological characterisation and FC assay both demonstrated that CTPF, and not FTPF possessed induced-apoptotic activity. CTPF potentially induced cell apoptosis by promoting oxidative stress. FTPF indicated pro-oxidation at a concentration of 10 µg/mL and anti-oxidation capabilities at higher concentrations. ROS scavenging assay by oxidation-stress model indicated that CTPF (10 - 400 µg/mL) had ROS inhibitory capacity (R2 = 0.5156, p < 0.0001). FTPF (10 - 100 µg/mL) boosted the level of ROS (p < 0.0001) and inhibited the generation of ROS at 100-400 µg/mL (R2 = 0.5951, p < 0.0001). CTPF is a potential candidate requiring further exploration for the development of antihepatoma ingredients. The down-regulation of cell viability was related to production and reduction of cellular ROS.


Assuntos
Antioxidantes/farmacologia , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Physalis/química , Extratos Vegetais/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Flavonoides/farmacologia , Humanos , Neoplasias Hepáticas/patologia , Estresse Oxidativo/efeitos dos fármacos , Fenóis/farmacologia , Espécies Reativas de Oxigênio/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA