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1.
Cancer Sci ; 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32073706

RESUMO

Resistance to chemotherapy is a major challenge for the treatment of patients with colorectal cancer (CRC). Previous studies have found that microRNAs (miRNAs) play key roles in drug resistance; however, the role of miRNA-373-3p (miR-375-3p) in CRC remains unclear. The current study aimed to explore the potential function of miR-375-3p in 5-fluorouracil (5-FU) resistance. MicroRNA-375-3p was found to be widely downregulated in human CRC cell lines and tissues and to promote the sensitivity of CRC cells to 5-FU by inducing colon cancer cell apoptosis and cycle arrest and by inhibiting cell growth, migration, and invasion in vitro. Thymidylate synthase (TYMS) was found to be a direct target of miR-375-3p, and TYMS knockdown exerted similar effects as miR-375-3p overexpression on the CRC cellular response to 5-FU. Lipid-coated calcium carbonate nanoparticles (NPs) were designed to cotransport 5-FU and miR-375-3p into cells efficiently and rapidly and to release the drugs in a weakly acidic tumor microenvironment. The therapeutic effect of combined miR-375 + 5-FU/NPs was significantly higher than that of the individual treatments in mouse s.c. xenografts derived from HCT116 cells. Our results suggest that restoring miR-375-3p levels could be a future novel therapeutic strategy to enhance chemosensitivity to 5-FU.

2.
Sci Rep ; 9(1): 18492, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31811256

RESUMO

Development of plant tissues is dependent on numerous factors, including hormone activity, signaling, cell division, and elongation. In plants, Defective Entry into Mitosis 1 (Dim1) homologs are recognized as pivotal in leaf senescence and progress of normal growth, but their role in rice has not been functionally characterized. The findings presented in this paper suggest that OsDim1 is important in early seedling development, pollen tube elongation, and impacts rice yield components. The gene is expressed in the scutellum, endosperm, embryonic root, shoot, pollen grains and tubes, as well as in several organs of the rice flower. According to the present study findings, RNAi mediated knockdown of OsDim1 resulted in phytohormonal imbalance, reduced amylase activity, affected differentiation of embryonic root elongation zone tissues, suppressed embryonic root and shoot growth, and impaired pollen tube elongation. In contrast, overexpression of OsDim1 showed significant growth in embryonic roots and shoots, while it increased culm length, total number of tillers per plant, seed setting rate, and total number of grains per panicle compared to its wild type line. In summary, we propose OsDim1 plays an important role in seedling growth and pollen tube elongation, and has pleiotropic effects on reproductive tissues.

3.
Microb Cell Fact ; 18(1): 118, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31262296

RESUMO

BACKGROUND: Enzymatic glycan synthesis has leapt forward in recent years and a number of glucuronosyltransferase (EC 2.4.1.17) have been identified and prepared, which provides a guide to an efficient approach to prepare glycans containing glucuronic acid (GlcA) residues. The uridine 5'-diphosphate (UDP) activated form, UDP-GlcA, is the monosaccharide donor for these glucuronidation reactions. RESULTS: To produce UDP-GlcA in a cost-effective way, an efficient three-step cascade route was developed using whole cells expressing hyperthermophilic enzymes to afford UDP-GlcA from starch. By coupling a coenzyme regeneration system with an appropriate expression level with UDP-glucose 6-dehydrogenase in a single strain, the cells were able to meet NAD+ requirements. Without addition of exogenous NAD+, the reaction produced 1.3 g L-1 UDP-GlcA, representing 100% and 46% conversion of UDP-Glc and UTP respectively. Finally, an anion exchange chromatography purification method was developed. UDP-GlcA was successfully obtained from the cascade system. The yield of UDP-GlcA during purification was about 92.0%. CONCLUSIONS: This work built a de novo hyperthermophilic biosynthetic cascade into E. coli host cells, with the cells able to meet NAD+ cofactor requirements and act as microbial factories for UDP-GlcA synthesis, which opens a door to large-scale production of cheaper UDP-GlcA.


Assuntos
Escherichia coli/metabolismo , Engenharia Metabólica/métodos , Uridina Difosfato Ácido Glucurônico/biossíntese , Vias Biossintéticas , Escherichia coli/genética , Glucuronatos/biossíntese , Glucuronosiltransferase/metabolismo
4.
J Exp Bot ; 70(4): 1197-1207, 2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30576523

RESUMO

Hybrid weakness is a post-zygotic hybridization barrier frequently observed in plants, including rice. In this study, we describe the genomic variation among three temperate japonica rice (Oryza sativa ssp. japonica) varieties 'Aranghyangchalbyeo' ('CH7'), 'Sanghaehyangheolua' ('CH8') and 'Shinseonchalbyeo' ('CH9'), carrying different hybrid weakness genes. The reciprocal progeny obtained from crossing any two varieties displayed characteristic hybrid weakness traits. We mapped and cloned a new locus, Hwc3 (hybrid weakness 3), on chromosome 4. Sequence analysis identified that a long terminal repeat (LTR) retrotransposon was inserted into the promoter region of the Hwc3 gene in 'CH7'. A 4-kb DNA fragment from 'CH7' containing the Hwc3 gene with the inserted LTR retrotransposon was able to induce hybrid weakness in hybrids with 'CH8' plants carrying the Hwc1 gene by genetic complementation. We investigated the differential gene expression profile of F1 plants exhibiting hybrid weakness and detected that the genes associated with energy metabolism were significantly down-regulated compared with the parents. Based on our results, we propose that LTR retrotransposons could be a potential cause of hybrid weakness in intrasubspecific hybrids in japonica rice. Understanding the molecular mechanisms underlying intrasubspecific hybrid weakness is important for increasing our knowledge on reproductive isolation and could have significant implications for rice improvement and hybrid breeding.

5.
Inorg Chem ; 57(7): 3865-3872, 2018 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-29553262

RESUMO

For exploring the multifold helical fabrication of polyoxometalate (POM)-based hybrid compounds, four POM-based crystalline compounds with different meso-helices, H3[Ag27(trz)16(H2O)6][SiW12O40]2·5H2O (1), H[Ag27(trz)16(H2O)4][PW12O40]2·2H2O (2), [Ag23(trz)14(H2O)2][HSiW12O40] (3), and [Ag23(trz)14(H2O)2][PW12O40] (4), were successfully isolated by using the delicate 1,2,3-triazole ligand and silver ions in this work. Crystal analysis reveals that compounds 1 and 2 and compounds 3 and 4 are isomorphous and display 2-/4-fold mixed meso-helices and simple 2-fold meso-helices, respectively. In addition, due to the reversible multielectron redox behavior and electron storage functions of POMs, compounds 1 and 3 were studied as anode materials in lithium-ion batteries (LIBs). Compounds 1 and 3 show very high lithiation capacities (1356 and 1140 mAh g-1, respectively) in the initial cycle, which are much higher than those of (NBu4)4[SiW12O40] and commercial graphite at the current density of 100 mA g-1. More importantly, both compounds also show good stable performance after 100 cycles.

6.
Dalton Trans ; 47(14): 4827-4832, 2018 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-29541703

RESUMO

We utilise the dual synthesis strategy in terms of bimetallic inorganic building blocks and sulfur containing organic ligand. A novel sulfur-containing bimetallic metal organic framework (Fe2Co-TPDC) with two types of 4-fold meso-helical structures has been successfully synthesized. Benefitting from the uniform distribution of active sulfur sites and the structural stability of the mixed-metallic method, Fe2Co-TPDC can efficiently prevent a shuttle behavior of sulfur and endow a commendable specific capacity. As far as we know, this is the first time that a sulfur-containing bimetallic crystalline MOF with helical structure and prominent specific capacity and remarkable cycling stability has served as an electrode material for LIBs.

7.
Dalton Trans ; 46(8): 2456-2461, 2017 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-28112321

RESUMO

The crystal structure of Cd-MOF-74 was obtained for the first time that possesses high sensitivity for the detection of copper ions from water and simulated biological fluids based on changes in luminescent intensity. Furthermore, Cd-MOF-74 could selectively remove Cu2+ from simulated biological fluids that contain Mg2+, Co2+, Zn2+, Fe2+, Ni2+, Na+, and K+. The adsorption capacity of this adsorbent for copper ions reached 189.5 mg g-1 and it quickly adsorbed copper ions within 10 minutes under 10 ppm Cu2+ in the simulated biological system. XPS, PXRD, and gas adsorption measurements revealed that this high sensitivity and selectivity of Cd-MOF-74 resulted from the partial substitution of Cd2+ by Cu2+ in the framework. Although many MOF materials have been employed for sensor or selective adsorption of Cu2+, Cd-MOF-74 is the first example of MOFs showing both capabilities in simulated biological fluids, which represents a pioneering work that extends the applications of MOF materials in the biological field.


Assuntos
Líquidos Corporais/química , Cobre/análise , Cobre/isolamento & purificação , Limite de Detecção , Substâncias Luminescentes/química , Estruturas Metalorgânicas/química , Adsorção , Biomimética , Cádmio/química , Cobre/química , Modelos Moleculares , Conformação Molecular
8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 37(3): 919-23, 2017 Mar.
Artigo em Chinês, Inglês | MEDLINE | ID: mdl-30160424

RESUMO

The mineral constituents of the rock sample can be analyzed with in-situ energy dispersive X-ray fluorescence analysis technology (In-situ EDXRF), the matrix effect of rock sample will effects on measurement results. The Monte Carlo simulation method is used to conduct fluorescence analysis spectrum with ideal measurement conditions, which provides analytical data for matrix effect research. The measured spectrum of seventeen kinds rock samples are being simulated, which has the same Cu content. Therefore, the influences with matrix effect of rock sample in in-situ EDXRF take Cu element for example. Based on correlation between Cu Kα X-ray intensity and spectral parameters, considering elements similarity of all kinds rock samples, it is found that the variation the Cu Kα X-ray intensity not only by the control of rock elements composition or rock classification. The matrix effect of rock samples must be classified according correlation between Cu Kα X-ray intensity and spectral parameters. After the matrix effect classification, fifteen kinds of rock samples, which belong to the same matrix effect, can be corrected more effective. Based on principal component analysis of similar matrix effect rock samples, it is found that the scattering background, target element K-series X-ray of X-ray tube and its incoherent scatter intensity can be a good description of Cu Kα X-ray intensity which is affected by rock matrix, thus it can be used to correct the Cu element measurement results. Certainly, this technology can also provide reference for matrix effect correction to other elements in rock.

9.
ACS Appl Mater Interfaces ; 8(48): 33183-33188, 2016 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-27934177

RESUMO

We designed and fabricated a fluorophore-containing tetradentate carboxylate ligand-based metal-organic framework (MOF) material with open and semiopen channels, which acted as the host for sulfur trapped in Li-S batteries and sensor of benzene homologues. These channels efficiently provide a π-π* conjugated matrix for the charge transfer and guest molecule trapping. The open channel ensured a much higher loading quantitative of sulfur (S content-active material, 72 wt %; electrode, 50.4 wt %) than most of the MOF/sulfur composites, while the semiopen channel possessing aromatic rings tentacles guaranteed an outstanding specific discharge capacity (1092 mA h g-1 at 0.1 C) accompanied by good cycling stability. To our surprise, benefiting from special π-π* conjugated conditions, compound 1 could be a chemical sensor for benzene homologues, especially for 1,2,4-trimethylbenzene (1,2,4-TMB). This is the first example of MOFs materials serving as a sensor of 1,2,4-TMB among benzene homologues. Our works may be worthy of use for references in other porous materials systems to manufacture more long-acting Li-S batteries and sensitive chemical sensors.

10.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 33(9): 1242-6, 2013 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-24273982

RESUMO

OBJECTIVE: To observe the effect of Jiedu Sangen Decoction (JSD, consisting of Polygonum cuspidatum, Geum Japonicum Thumnb, Radix Actinidiae Chinensis) on the migration capability of colon cancer CT-26 cells were observed, and on expressions of carcinoma-associated fibroblasts (CAFs) such as transforming growth factor-beta1 (TGF-beta1), matrix metalloproteinase 9 (MMP-9), and alpha-smooth muscle actin (alpha-SMA). METHODS: The BALB/C mice were subcutaneously inoculated with colon cancer CT-26 cells (1.2 x 10(6)mL) and then randomly divided into 3 groups, i.e., the normal control group, the model group, the JSD treated group. The effects of three different serums on the migration ability of colon cancer CT-26 cells were observed using Transwell. The expression quantities of TGF-beta1 and MMP-9 in the supernatant of CAFs were detected using ELISA. The mRNA expression quantities of TGF-beta1 and alpha-SMA in CAFs were detected by real-time fluorescence quantitative PCR. RESULTS: The number of semi-permeable film cells in the JSD treated group significantly decreased, when compared with the model group, showing statistical significance (P < 0.01). Compared with the model group, the expressions of TGF-beta1 and MMP-9 in the supernatant of CAFs decreased in the JSD treated group at 24 and 48 h, showing statistical difference (P < 0.05, P < 0.01). Compared with the model group, the mRNA expressions of TGF-beta1 and alpha-SMA in the JSD treated group obviously decreased, showing statistical difference (P < 0.01). CONCLUSION: JSD could decrease expressions of TGF-beta1 and MMP-9 in the supernatant of CAFs, lower mRNA expressions of alpha-SMA and TGF-beta1, which might be possible mechanisms for inhibiting the migration and invasion of tumor cells.


Assuntos
Neoplasias do Colo/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Fibroblastos/metabolismo , Animais , Linhagem Celular Tumoral , Neoplasias do Colo/patologia , Fibroblastos/efeitos dos fármacos , Humanos , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Invasividade Neoplásica , Metástase Neoplásica , Fator de Crescimento Transformador beta1/metabolismo
11.
Dalton Trans ; 42(21): 7803-9, 2013 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-23558903

RESUMO

A new hybrid compound, Na[Ag6(pyttz)2(H2O)][PMo12O40] (pyttz = 3-(pyrid-3-yl)-5-(1H-1,2,4-triazol-3-yl)-1,2,4-triazolyl), has been hydrothermally synthesized and structurally characterized by routine techniques. X-ray diffraction analysis reveals that the title compound is constructed by the 2D Ag-pyttz coordination polymer and 3D Ag-POM architecture with helix. A fascinating structural feature is the assembling fashion of the right- and left-helical chain, namely, the helical chains with different orientations are intertwined with each other forming intertwined double helical layers along the c-axis, and the identical left- or right-handed helical chains are fused together in a hand-by-hand mode generating another homological helical layer along the a-axis. As a result, these helical layers intersect each other obtaining an unprecedented 3D POM-Ag inorganic architecture. Note that the 3D framework with a helix constructed by POMs and metal ions has never been observed up to date. Additionally, its photocatalytic degradation of RhB was also investigated.


Assuntos
Compostos Organometálicos/química , Prata/química , Compostos de Tungstênio/química , Catálise , Cristalografia por Raios X , Modelos Moleculares , Compostos Organometálicos/síntese química , Fotólise , Rodaminas/química , Triazóis/síntese química , Triazóis/química , Compostos de Tungstênio/síntese química
12.
Dalton Trans ; 42(5): 1667-77, 2013 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-23154678

RESUMO

To investigate the influence of a secondary spacer on the resulting structures of POMOFs containing pytz, five new compounds with different dimensionalities, [Cu(5)(2-pytz)(6)(H(2)O)(4)][SiMo(12)O(40)]·3H(2)O (1), [Cu(3)(2-pytz)(4)bipy][H(2)SiMo(12)O(40)]·bipy (2), [Cu(3)(2-pytz)(2)(bipy)(4)(H(2)O)(6)][H(4)SiW(12)O(40)](2)·6H(2)O (3), [Cu(2)(2-pytz)(phen)(OH)](2)[SiW(12)O(40)]·H(2)O (4), [Cu(3)(4-pytz)(4)(H(2)O)(4)][H(2)SiW(12)O(40)]·2H(2)O (5), were synthesized. When only 2-pytz was employed, compound 1 with a 3D framework was obtained, whereas when the secondary spacers (4,4'-bipy, phen and 4-pytz) were introduced into the reaction system of 1, compounds 2-5 were obtained and exhibit a broad range of structures, including 0D, 1D, 2D and 3D frameworks. It can be observed from the architectures of compounds 1-5 that the secondary spacers have a great effect on the structures of the MOFs, which results in the formation of various dimensional POMOF compounds. Additionally, photocatalytic experiments of 1-5 for the photocatalytic degradation of RhB under UV irradiation were also investigated.


Assuntos
Complexos de Coordenação/química , Cobre/química , Compostos de Tungstênio/química , Complexos de Coordenação/síntese química , Cristalografia por Raios X , Conformação Molecular , Fotólise , Rodaminas/química , Raios Ultravioleta
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