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1.
J Biol Chem ; 300(3): 105754, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38360270

RESUMO

KDELR (Erd2 [ER retention defective 2] in yeasts) is a receptor protein that retrieves endoplasmic reticulum (ER)-resident proteins from the Golgi apparatus. However, the role of the KDELR-mediated ER-retrieval system in regulating cellular homeostasis remains elusive. Here, we show that the absence of Erd2 triggers the unfolded protein response (UPR) and enhances mitochondrial respiration and reactive oxygen species in an UPR-dependent manner in the fission yeast Schizosaccharomyces pombe. Moreover, we perform transcriptomic analysis and find that the expression of genes related to mitochondrial respiration and the tricarboxylic acid cycle is upregulated in a UPR-dependent manner in cells lacking Erd2. The increased mitochondrial respiration and reactive oxygen species production is required for cell survival in the absence of Erd2. Therefore, our findings reveal a novel role of the KDELR-Erd2-mediated ER-retrieval system in modulating mitochondrial functions and highlight its importance for cellular homeostasis in the fission yeast.


Assuntos
Retículo Endoplasmático , Mitocôndrias , Schizosaccharomyces , Resposta a Proteínas não Dobradas , Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático , Mitocôndrias/genética , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo
2.
Proc Natl Acad Sci U S A ; 119(44): e2205548119, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36279443

RESUMO

Air pollution levels in the United States have decreased dramatically over the past decades, yet national racial-ethnic exposure disparities persist. For ambient fine particulate matter ([Formula: see text]), we investigate three emission-reduction approaches and compare their optimal ability to address two goals: 1) reduce the overall population average exposure ("overall average") and 2) reduce the difference in the average exposure for the most exposed racial-ethnic group versus for the overall population ("national inequalities"). We show that national inequalities in exposure can be eliminated with minor emission reductions (optimal: ~1% of total emissions) if they target specific locations. In contrast, achieving that outcome using existing regulatory strategies would require eliminating essentially all emissions (if targeting specific economic sectors) or is not possible (if requiring urban regions to meet concentration standards). Lastly, we do not find a trade-off between the two goals (i.e., reducing overall average and reducing national inequalities); rather, the approach that does the best for reducing national inequalities (i.e., location-specific strategies) also does as well as or better than the other two approaches (i.e., sector-specific and meeting concentration standards) for reducing overall averages. Overall, our findings suggest that incorporating location-specific emissions reductions into the US air quality regulatory framework 1) is crucial for eliminating long-standing national average exposure disparities by race-ethnicity and 2) can benefit overall average exposures as much as or more than the sector-specific and concentration-standards approaches.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Estados Unidos , Humanos , Poluentes Atmosféricos/análise , Etnicidade , Exposição Ambiental/prevenção & controle , Exposição Ambiental/análise , Poluição do Ar/prevenção & controle , Poluição do Ar/análise , Material Particulado/análise
3.
Neurol Sci ; 45(2): 601-612, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37656288

RESUMO

BACKGROUND: Three-Hz postural leg tremor has recently been identified as highly prevalent in patients with the cerebellar type of multiple system atrophy, but its impact on posture maintenance remains poorly understood. PATIENTS AND METHODS: Thirty-seven patients with spinocerebellar ataxia and 58 others with cerebellar type of multiple system atrophy were given Synapsys posturography examinations. Fifty-three healthy controls were also tested. Low, medium, and high-frequency sway were recorded to compute energy values. Frequency shift and postural strategy predominance were evaluated from the postural sway distributions, mainly from the proportions of higher frequency values among the total values. The trajectories of postural sway components were evaluated with the generalized additive mixed model. Distributions of the components and their relationships with falls and tremors were assessed through repeated measures correlation analysis. RESULTS: As the test difficulty increased, the standard controls showed slight increases in the energy values at every frequency. Distributions of the higher frequency (>0.5 Hz) values increased escalatingly with test difficulty, illustrating frequency shifts and hip strategy predominance. Medium and high-frequency values were strongly and positively inter-correlated in normal stances, but this was not observed among the spinocerebellar ataxia or multiple system atrophy patients. Unlike normal stances, the proportion of medium frequency values was negatively related to the total value among the spinocerebellar ataxia and multiple system atrophy patients, implying a failure of frequency shift in response to perturbation. Medium frequency proportions were also inversely correlated with tremors among the multiple system atrophy patients. CONCLUSIONS: The observed synchronized changes in medium and high-frequency postural sway indicate that they constitute a complete hip strategy for posture control. The strategy was rigid in those with spinocerebellar ataxia but completely disrupted in those with multiple system atrophy. Three Hertz postural leg tremors destabilize the ankle joints and interfere with postural adjustment among those with multiple system atrophy.


Assuntos
Atrofia de Múltiplos Sistemas , Ataxias Espinocerebelares , Humanos , Tremor , Atrofia de Múltiplos Sistemas/complicações , Perna (Membro) , Postura/fisiologia , Equilíbrio Postural/fisiologia
4.
J Virol ; 96(5): e0172321, 2022 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-35019714

RESUMO

Hepatitis B virus (HBV) large (L) envelope protein is translated from 2.4-kb RNA. It contains preS1, preS2, and S domains and is detected in Western blotting as p39 and gp42. The 3.5-kb pregenomic RNA produces core and polymerase (P) proteins. We generated L-minus mutants of a genotype A clone and a genotype D clone from 1.1-mer or 1.3-mer construct, with the former overproducing pregenomic RNA. Surprisingly, mutating a preS1 ATG codon(s) or introducing a nonsense mutation soon afterwards switched secreted p39/gp42 to a p41/p44 doublet, with its amount further increased by a nonsense mutation in the core gene. A further-downstream preS1 nonsense mutation prevented p41/p44 production. Tunicamycin treatment confirmed p44 as the glycosylated form of p41. In this regard, splicing of 3.5-kb RNA to generate a junction at nucleotides (nt) 2447 to 2902 for genotype D enables translation of p43, with the N-terminal 47 residues of P protein fused to the C-terminal 371 residues of L protein. Indeed p41/p44 were detectable by an antibody against the N terminus of P protein and eliminated by a nonsense mutation at the 5' P gene or a point mutation to prevent that splicing. Therefore, lost L (and core) protein expression from the 1.1-mer or 1.3-mer construct markedly increased p41/p44 (p43), the P-L fusion protein. Cotransfection with an expression construct for L/M proteins reversed high extracellular p41/p44 associated with L-minus mutants, suggesting that L protein retains p43 in wild-type HBV to promote its intracellular degradation. Considering that p43 lacks N-terminal preS1 sequence critical for receptor binding, its physiological significance during natural infection and therapeutic potential warrant further investigation. IMPORTANCE The large (L) envelope protein of hepatitis B virus (HBV) is translated from 2.4-kb RNA and detected in Western blotting as p39 and gp42. Polymerase (P) protein is expressed at a low level from 3.5-kb RNA. The major spliced form of 3.5-kb RNA will produce a fusion protein between the first 47 residues of P protein and a short irrelevant sequence, although also at a low level. Another spliced form has the same P protein sequence fused to L protein missing its first 18 residues. We found that some point mutations to eliminate L and core protein expression from overlength HBV DNA constructs converted p39/gp42 to p41/gp44, which turned out to be the P-L fusion protein. Thus, the P-L fusion protein can be expressed at extremely high level when L protein expression is prevented. The underlying mechanism and functional significance of this variant form of L protein warrant further investigation.


Assuntos
Antígenos de Superfície da Hepatite B , Vírus da Hepatite B , Herpesvirus Cercopitecino 1 , Precursores de Proteínas , Proteínas do Envelope Viral , Proteínas Virais de Fusão , Códon sem Sentido/metabolismo , Genótipo , Hepatite B/virologia , Antígenos de Superfície da Hepatite B/genética , Vírus da Hepatite B/genética , Vírus da Hepatite B/metabolismo , Herpesvirus Cercopitecino 1/genética , Humanos , Mutação , Precursores de Proteínas/genética , Proteínas do Envelope Viral/genética , Proteínas Virais de Fusão/genética
5.
Plant Physiol ; 190(2): 1526-1542, 2022 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-35866684

RESUMO

Identifying trait-associated genes is critical for rice (Oryza sativa) improvement, which usually relies on map-based cloning, quantitative trait locus analysis, or genome-wide association studies. Here we show that trait-associated genes tend to form modules within rice gene co-expression networks, a feature that can be exploited to discover additional trait-associated genes using reverse genetics. We constructed a rice gene co-expression network based on the graphical Gaussian model using 8,456 RNA-seq transcriptomes, which assembled into 1,286 gene co-expression modules functioning in diverse pathways. A number of the modules were enriched with genes associated with agronomic traits, such as grain size, grain number, tiller number, grain quality, leaf angle, stem strength, and anthocyanin content, and these modules are considered to be trait-associated gene modules. These trait-associated gene modules can be used to dissect the genetic basis of rice agronomic traits and to facilitate the identification of trait genes. As an example, we identified a candidate gene, OCTOPUS-LIKE 1 (OsOPL1), a homolog of the Arabidopsis (Arabidopsis thaliana) OCTOPUS gene, from a grain size module and verified it as a regulator of grain size via functional studies. Thus, our network represents a valuable resource for studying trait-associated genes in rice.


Assuntos
Oryza , Antocianinas/metabolismo , Grão Comestível/genética , Redes Reguladoras de Genes , Estudo de Associação Genômica Ampla , Oryza/genética , Oryza/metabolismo , Locos de Características Quantitativas/genética
6.
Microb Pathog ; 180: 106158, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37201637

RESUMO

PRRSV-1 has caused more clinical infections in pigs in Chinese swine herds in recent years, however, the pathogenicity of PRRSV-1 in China is unclear. In order to study the pathogenicity of PRRSV-1, in this study, a PRRSV-1 strain, 181187-2, was isolated in primary alveolar macrophage (PAM) cells from a farm where abortions had been reported in China. The complete genome of 181187-2 was 14932 bp excluding Poly A, with 54-amino acid continuous deletion in the Nsp2 gene and 1 amino deletion in ORF3 gene compared with LV. Additionally, the piglets inoculated with strain 181187-2 by intranasal and intranasal plus intramuscular injection, animal experiments showed clinical symptoms including transient fever and depression, with no death. The obvious histopathological lesions including interstitial pneumonia and lymph node hemorrhage, and there were no significant differences in clinical symptoms and histopathological lesions with different challenge ways. Our results indicated that PRRSV -1 181187-2 was a moderately pathogenic strain in piglets.


Assuntos
Síndrome Respiratória e Reprodutiva Suína , Vírus da Síndrome Respiratória e Reprodutiva Suína , Animais , Suínos , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Virulência , Sequência de Aminoácidos , Genoma Viral , Filogenia , China
7.
J Acoust Soc Am ; 154(4): 2609-2624, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37877772

RESUMO

Honeycomb sandwich structures have been widely used in the field of engineering owing to their outstanding mechanical properties. However, for a honeycomb sandwich structure with large spatial periodicity, there is a low-frequency sound insulation valley. Here, the sound transmission across locally resonant honeycomb sandwich meta-structures was investigated to overcome this sound-insulation valley. An analytical model was developed based on the space-harmonic approach and the low-frequency sound insulation valley was determined analytically and numerically. The results indicate that the resonator distributed at the center of the face panel has a significant impact on the sound transmission performance of the honeycomb sandwich structure, whereas the resonator distributed on the wall of the honeycomb core does not contribute to overcoming this sound-insulation valley. Based on the research results, a design strategy for overcoming this sound-insulation valley was determined by tuning the damping parameter and constructing graded resonators. Moreover, sound transmission under the excitation of oblique incidence sound waves was also investigated. Compared with the method of filling porous materials, the proposed design method is more effective, and more importantly, the mass of the resonator is only 1.23% of that of the porous materials.

8.
Bioprocess Biosyst Eng ; 46(6): 893-901, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37079130

RESUMO

Eicosapentaenoic acid (EPA) belonged to the ω-3 series of polyunsaturated fatty acids and had physiological functions lipid as regulating blood lipid and preventing cardiovascular diseases. Schizochytrium sp. was considered to be a potential industrial fermentation strain of EPA because of its fast growth, high oil content, and simple fatty acid composition. However, Schizochytrium sp. produced EPA with low production efficiency and a long synthesis path. This research aims to improve the yield of EPA in Schizochytrium sp. by ARTP mutagenesis and to reveal the mechanism of high-yield EPA through transcriptome analysis. ARTP mutagenesis screening yielded the mutant M12 that whereas the productivity of EPA increased 108% reaching 0.48 g/L, the total fatty acid concentration was 13.82 g/L with an increase of 13.7%. The transcriptomics revealed 2995 differentially expressed genes were identified between M12 and the wild-type strain and transcripts involved in carbohydrate, amino acid, energy, and lipid metabolism were up-regulated. Among them, the hexokinase (HK) and the phosphofructokinase genes (PFK), which can catalyze pyruvate to acetyl-CoA, were increased 2.23-fold and 1.78-fold. Glucose-6-phosphate dehydrogenase (G6PD) and glutamate dehydrogenase (GLDH), which can both generate NADPH, were increased by 1.67-fold and 3.11-fold. Furthermore, in the EPA synthesis module, the expression of 3-oxoacyl-[acyl-carrier protein] reductase(fabG) and carbonyl reductase 4 / 3-oxoacyl-[acyl-carrier protein] reductase beta subunit(CBR4), also up-regulated 1.11-fold and 2.67-fold. These may lead to increases in cell growth. The results provide an important reference for further research on promoting fatty acid and EPA accumulation in Schizochytrium sp.


Assuntos
Ácido Eicosapentaenoico , Estramenópilas , Ácido Eicosapentaenoico/metabolismo , Ácidos Docosa-Hexaenoicos/metabolismo , Ácidos Graxos/metabolismo , Mutagênese , Oxirredutases/metabolismo , Proteínas de Transporte/genética
9.
Molecules ; 28(22)2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-38005368

RESUMO

There is an urgent need to realize precise clinical ultrasound with ultrasound contrast agents that provide high echo intensity and mechanical index tolerance. Graphene derivatives possess exceptional characteristics, exhibiting great potential in fabricating ideal ultrasound contrast agents. Herein, we reported a facile and green approach to synthesizing reduced graphene oxide with ellagic acid (rGO-EA). To investigate the application of a graphene derivative in ultrasound contrast agents, rGO-EA was dispersed in saline solution and mixed with SonoVue (SV) to fabricate SV@rGO-EA microbubbles. To determine the properties of the product, analyses were performed, including ultraviolet-visible spectroscopy (UV-vis), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), X-ray photoelectron spectrum (XPS), X-ray diffraction analysis (XRD) and zeta potential analysis. Additionally, cell viability measurements and a hemolysis assay were conducted for a biosafety evaluation. SV@rGO-EA microbubbles were scanned at various mechanical index values to obtain the B-mode and contrast-enhanced ultrasound (CEUS) mode images in vitro. SV@rGO-EA microbubbles were administered to SD rats, and their livers and kidneys were imaged in CEUS and B-mode. The absorption of rGO-EA resulted in an enhanced echo intensity and mechanical index tolerance of SV@rGO-EA, surpassing the performance of SV microbubbles both in vitro and in vivo. This work exhibited the application potential of graphene derivatives in the field of ultrasound precision medicine.


Assuntos
Grafite , Ratos , Animais , Grafite/química , Óxidos/química , Ácido Elágico/farmacologia , Meios de Contraste/farmacologia , Microbolhas , Ratos Sprague-Dawley , Análise Espectral Raman
10.
J Biol Chem ; 297(4): 101212, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34547291

RESUMO

Sex as a physiologic factor has a strong association with the features of metabolic syndrome. Our previous study showed that loss of the voltage-gated proton channel Hv1 inhibits insulin secretion and leads to hyperglycemia and glucose intolerance in male mice. However, there are significant differences in blood glucose between male and female Hv1-knockout (KO) mice. Here, we investigated the differences in glucose metabolism and insulin sensitivity between male and female KO mice and how sex steroids contribute to these differences. We found that the fasting blood glucose in female KO mice was visibly lower than that in male KO mice, which was accompanied by hypotestosteronemia. KO mice in both sexes exhibited higher expression of gluconeogenesis-related genes in liver compared with WT mice. Also, the livers from KO males displayed a decrease in glycolysis-related gene expression and an increase in gluconeogenesis-related gene expression compared with KO females. Furthermore, exogenous testosterone supplementation decreased blood glucose levels in male KO mice, as well as enhancing insulin signaling. Taken together, our data demonstrate that knockout of Hv1 results in higher blood glucose levels in male than female mice, despite a decreased insulin secretion in both sexes. This sex-related difference in glucose homeostasis is associated with the glucose metabolism in liver tissue, likely due to the physiological levels of testosterone in KO male mice.


Assuntos
Glicemia , Gluconeogênese , Glicólise , Canais Iônicos/deficiência , Fígado/metabolismo , Caracteres Sexuais , Animais , Glicemia/genética , Glicemia/metabolismo , Feminino , Regulação da Expressão Gênica , Canais Iônicos/metabolismo , Masculino , Camundongos , Camundongos Knockout , Transdução de Sinais
11.
Microb Cell Fact ; 21(1): 191, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36109777

RESUMO

Escherichia coli, one of the most efficient expression hosts for recombinant proteins (RPs), is widely used in chemical, medical, food and other industries. However, conventional expression strains are unable to effectively express proteins with complex structures or toxicity. The key to solving this problem is to alleviate the host burden associated with protein overproduction and to enhance the ability to accurately fold and modify RPs at high expression levels. Here, we summarize the recently developed optimization strategies for the high-level production of RPs from the two aspects of host burden and protein activity. The aim is to maximize the ability of researchers to quickly select an appropriate optimization strategy for improving the production of RPs.


Assuntos
Escherichia coli , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Recombinantes
12.
Nanotechnology ; 33(45)2022 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-35905646

RESUMO

Flexible organic light emitting diodes (OLED) have attracted great attention in many applications. MXene based flexible transparent conductive films (TCFs) are the most promising next-generation electrodes for flexible electronics. Herein, the sandwich conductive structure of silver nanowires (AgNWs) network, new 2D nanosheets with excellent conductivity, hydrophilicity and mechanical flexibility and PEDOT:PSS contributes to a highly transparent and conductive hybrid electrode through a simple, scalable, low-cost spray method. The Ti3C2Tx/AgNWs/PEDOT-PET film shows a low sheet resistance (<30 Ω/sq) and high transmittance (>80%) at 550 nm. Flexible OLED with such hybrid anode has the maximum brightness, current efficiency and current density, as high as 10 040 cd m-2, 3.7 cd A-1and 535.5 mA cm-2, respectively. These results indicate that the novel Ti3C2Tx/AgNWs/PEDOT-PET TCFs have a great potential for high-performance flexible optoelectronic devices.

13.
Mol Biol Rep ; 49(9): 8761-8775, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35771357

RESUMO

BACKGROUND: Circular RNAs (circRNAs), new members of the noncoding RNA family, have been reported to participate in various pathological conditions, especially cancer. Pancreatic ductal adenocarcinoma (PDAC), as one of the most aggressive human solid tumors, is still with a low surgical cure rate. Exploring the role of circRNAs in PDAC is meaningful, and may offer a new therapeutic approach for PDAC. METHODS AND RESULTS: Competing endogenous RNA (ceRNA) microarray revealed that circ-0047078 was highly expressed in pancreatic ductal adenocarcinoma (PDAC) tissues compared with adjacent normal tissues, and the differential expression was further confirmed by PCR in both tissues and cell lines. Cell functional assays including cell counting kit-8 (CCK-8) assay, transwell invasion assay, flow cytometry and caspase activity assay demonstrated that circ-0047078 was positively correlated with the proliferation and invasion but negatively correlated with the apoptosis of CFPAC-1 cells. Circ-0047078 knockdown led to miR-11181, CXCL12 and MCAM downregulation and RGS16 upregulation, and the effect of circ-0047078 knockdown on CFPAC-1 cell behavior change can be reversed by miR-11181 mimic. Moreover, clinicopathological analysis indicated that circ-0047078 expression level was positively correlated with lymphatic metastasis and perineural invasion. In addition, knockdown of Chemokine (C-X-C motif) Ligand 12 (CXCL12) alone decreased proliferation, invasion, but increased apoptosis of CFPAC-1 cells, and raised the activity of caspase-3, caspase-8 and caspase-9 activity. Knockdown of Melanoma Cell Adhesion Molecule (MCAM) alone decreased invasion and increased apoptosis of CFPAC-1 cells, and both caspase-3 and caspase-9 activity increased, but no obvious change observed on caspase-8, and also no significant effect on CFPAC-1 cells proliferation. Knockdown of Regulator of G-protein signaling 16 (RGS16) alone increased invasion of CFPAC-1 cells, but had no significant effect on proliferation and apoptosis, of course, no obvious change on the activity of caspase-3, caspase-8 and caspase-9 had been observed. CONCLUSIONS: In conclusion, circ-0047078 plays a role in promoting PDAC via miR-11181 and then via CXCL12, MCAM and RGS16. Circ-0047078 may serve as a promising novel therapeutic target for PDAC patients.


Assuntos
Carcinoma Ductal Pancreático , MicroRNAs , Neoplasias Pancreáticas , Apoptose/genética , Antígeno CD146/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Caspase 3/metabolismo , Caspase 8/genética , Caspase 9/genética , Caspase 9/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Quimiocina CXCL12/genética , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias Pancreáticas/metabolismo , RNA Circular/genética , Neoplasias Pancreáticas
14.
Appl Microbiol Biotechnol ; 106(18): 6125-6137, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36056198

RESUMO

The combination of Escherichia coli BL21 (DE3) and the pET expression system is used extensively for the expression of various recombinant proteins (RPs). However, RP overexpression often introduces a growth burden for the host, especially in the case of toxic proteins. The key to solving this problem is to reduce the host burden associated with protein overproduction, which is often achieved by regulating the expression or activity of T7 RNAP or growth-decoupled systems. However, these strategies mainly relieve or interrupt the robbing of host resources, and do not eliminate other types of host burdens in the production process. In this study, we constructed a production system based on a dynamic equilibrium to precisely relieve the host burden and increase the RP production. The system is composed of three modules, including the overexpression of basic growth-related genes (rRNA, RNAP core enzyme, sigma factors), prediction and overexpression of key proteins using the enzyme-constrained model ec_iECBD_1354, and dynamic regulation of growth-related and key protein expression intensity based on a burden-driven promoter. Using this system, the production of many high-burden proteins, including autolysis protein and E. coli membrane proteins, was increased to varying degrees. Among them, the cytosine transporter protein (CodB) was most significantly improved, with a 4.02-fold higher production compared to the wild strain. This system can effectively reduce the optimizing costs, and is suitable for developing various types of RP expression hosts rapidly. KEY POINTS: • The basic growth-related resources can relieve the host burden from recombinant protein. • The enzyme-constrained model can accurately predict key genes to improve yield. • The expression intensity can be dynamically adjusted with changes in burden.


Assuntos
Proteínas de Escherichia coli , Escherichia coli , Proteínas de Transporte/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Regiões Promotoras Genéticas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
15.
Chemistry ; 27(29): 7968-7973, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-33784436

RESUMO

A concise enantioselective total synthesis of the neoclerodane diterpene (-)-salvinorin A is reported. The stereogenic center at C-12 was installed by catalytic asymmetric propargylation with excellent enantioselectivity, and the remaining six stereogenic centers were set up highly diastereoselectively under substrate control. As for our previous synthesis of racemic salvinorin A, two intramolecular Diels-Alder reactions were applied to generate the tricyclic core. A chemoselective Mitsunobu inversion of a syn 1,2-diol allowed for further streamlining of the original reaction sequence by two steps. Overall, (-)-salvinorin A was synthesized in only 16 steps starting from 3-furaldehyde with 1.4 % total yield. Furthermore, an alternative intramolecular Diels-Alder strategy employing a 2-bromo-1,3-diene moiety was investigated.


Assuntos
Diterpenos Clerodânicos , Catálise , Reação de Cicloadição , Estereoisomerismo
16.
Cerebellum ; 20(2): 246-253, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33164129

RESUMO

The aim of this study is to evaluate the prevalence and electrophysiological features of 3-Hz postural tremor in multiple system atrophy-cerebellar type and spinocerebellar ataxia. A static posturography examination was administered to 37 persons with spinocerebellar ataxia, 58 others with the cerebellar type of multiple system atrophy, and 53 healthy controls. During the sensory organization tests of 5 multiple system atrophy patients, surface electromyograms were recorded from bilateral tibialis anterior and medial gastrocnemius muscles. The patients with multiple system atrophy had, on average, significantly higher scores on the International Cooperative Ataxia Rating Scale and significantly greater prevalence of cross sign. Almost 80% of them fell during the posturography testing compared with two-thirds of the spinocerebellar ataxia patients. Twenty-seven percent of the spinocerebellar ataxia patients and 82.8% of those with multiple system atrophy displayed postural tremor with a frequency of approximately 3 Hz. The tremor's frequency tended to be lower in the spinocerebellar ataxia patients. The surface electromyography revealed highly coherent tremor activity at about 3 Hz in the patients' bilateral tibialis anterior and alternating firing in the bilateral antagonist muscles. Combining cross sign with a subject's static score of the International Cooperative Ataxia Rating Scale and occurrence of the tremor produced an indicator able to differentiate the two conditions with a sensitivity of 87.9% and a specificity of 89.2%. The area under the receiver operating characteristics curve for the indicator was 0.942. Three-hertz postural tremor is relatively characteristic of cerebellar type of multiple system atrophy and appears at an early stage of the disease. Identification of the tremor by posturography will facilitate its diagnosis.


Assuntos
Atrofia de Múltiplos Sistemas/complicações , Ataxias Espinocerebelares/complicações , Tremor/diagnóstico , Tremor/etiologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
17.
Microb Cell Fact ; 20(1): 189, 2021 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-34565359

RESUMO

Escherichia coli is the most widely used bacterium in prokaryotic expression system for the production of recombinant proteins. In BL21 (DE3), the gene encoding the T7 RNA polymerase (T7 RNAP) is under control of the strong lacUV5 promoter (PlacUV5), which is leakier and more active than wild-type lac promoter (PlacWT) under certain growth conditions. These characteristics are not advantageous for the production of those recombinant proteins with toxic or growth-burdened. On the one hand, leakage expression of T7 RNAP leads to rapid production of target proteins under non-inducing period, which sucks resources away from cellular growth. Moreover, in non-inducing or inducing period, high expression of T7 RNAP production leads to the high-production of hard-to-express proteins, which may all lead to loss of the expression plasmid or the occurrence of mutations in the expressed gene. Therefore, more BL21 (DE3)-derived variant strains with rigorous expression and different expression level of T7 RNAP should be developed. Hence, we replaced PlacUV5 with other inducible promoters respectively, including arabinose promoter (ParaBAD), rhamnose promoter (PrhaBAD), tetracycline promoter (Ptet), in order to optimize the production of recombinant protein by regulating the transcription level and the leakage level of T7 RNAP. Compared with BL21 (DE3), the constructed engineered strains had higher sensitivity to inducers, among which rhamnose and tetracycline promoters had the lowest leakage ability. In the production of glucose dehydrogenase (GDH), a protein that causes host autolysis, the engineered strain BL21 (DE3::ara) exhibited higher biomass, cell survival rate and foreign protein expression level than that of BL21 (DE3). In addition, these engineered strains had been successfully applied to improve the production of membrane proteins, including E. coli cytosine transporter protein (CodB), the E. coli membrane protein insertase/foldase (YidC), and the E. coli F-ATPase subunit b (Ecb). The engineered strains constructed in this paper provided more host choices for the production of recombinant proteins.


Assuntos
Clonagem Molecular/métodos , RNA Polimerases Dirigidas por DNA/genética , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Proteínas Recombinantes/biossíntese , Proteínas Virais/genética , Vetores Genéticos , Proteínas de Membrana Transportadoras/genética , Transporte Proteico , Proteínas Recombinantes/genética
18.
BMC Med Imaging ; 20(1): 78, 2020 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-32660445

RESUMO

BACKGROUND: Accurate identification of Parkinson's disease (PD) and Parkinsonism-Plus syndrome (PPS), especially in the early stage of the disease, is very important. The purpose of this study was to investigate the discriminative spatial pattern of cerebral blood flow (CBF) between patients with PD and PPS. METHODS: Arterial spin labeling (ASL) perfusion-weighted imaging was performed in 20 patients with PD (mean age 56.35 ± 7.56 years), 16 patients with PPS (mean age 59.62 ± 6.89 years), and 17 healthy controls (HCs, mean age 54.17 ± 6.58 years). Voxel-wise comparison of the CBF was performed among PD, PPS, and HC groups. The receiver operating characteristic (ROC) curve was used to evaluate the performance of CBF in discriminating between PD and PPS. The relationship between CBF and non-motor neuropsychological scores was assessed by correlation analysis. RESULTS: PD group showed a significantly decreased CBF in the right cerebelum_crus2, the left middle frontal gyrus (MFG), the triangle inferior frontal gyrus (IFG_Tri), the left frontal medial orbital gyrus (FG_Med_Orb) and the left caudate nucleus (CN) compared with the HC group (P < 0.05). Besides the above regions, the left supplementary motor area (SMA), the right thalamus had decreased CBF in the PPS group compared with the HC group (P < 0.05). PPS group had lower CBF value in the left MFG, the left IFG_Tri, the left CN, the left SMA, and the right thalamus compared with the PD group (P < 0.05). CBFs in left IFG_Tri, the left CN, the left SMA, and the right thalamus had moderate to high capacity in discriminating between PD and PPS patients (AUC 0.719-0.831). The CBF was positively correlated with the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores in PD patients, while positively correlated with the MMSE, Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD) scores in PPS patients (P < 0.05). CONCLUSION: PD and PPS patients have certain discriminative patterns of reduced CBFs, which can be used as a surrogate marker for differential diagnosis.


Assuntos
Doença de Parkinson/diagnóstico por imagem , Transtornos Parkinsonianos/diagnóstico por imagem , Imagem de Perfusão/métodos , Adulto , Idoso , Estudos de Casos e Controles , Circulação Cerebrovascular , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Testes de Estado Mental e Demência , Pessoa de Meia-Idade , Doença de Parkinson/psicologia , Transtornos Parkinsonianos/psicologia , Curva ROC , Marcadores de Spin
19.
Eye Contact Lens ; 46(4): 238-244, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32097180

RESUMO

OBJECTIVES: To evaluate the changes of corneal sub-basal nerve (SBN) and dendritic cell (DC) in contact lens (CL) wearers with mild dry eye and their potential relationship. METHODS: Twenty mild dry eye volunteers who had never worn CLs were recruited for long-term CL wearing. Each subject underwent ocular surface evaluations at baseline and at 1, 4, 12, and 24 weeks, including Ocular Surface Disease Index (OSDI) questionnaire, tear film break-up time (TBUT), and Schirmer I test. In vivo confocal microscopy was used to examine the density, area, number of dendrites, total dendritic length of DC, and SBN densities in central and peripheral corneas. Only right eyes were included. RESULTS: The DCs were activated and peaked at week 4 after wearing CLs. The peripheral DC density increased beginning the first week, whereas the central ones increased by week 4. After 4 weeks, both began to decrease, but still higher than baseline at week 24. The central and peripheral SBN densities decreased. However, the peripheral SBN tended to increase beginning at week 12. In early period, SBN was negatively correlated with DC parameters. After 4 weeks, the correlation changed to be positive. The OSDI increased, whereas the Schirmer I test and TBUT showed no significant change. CONCLUSIONS: After wearing CLs, corneal DC were activated and increased, indicating ocular surface inflammation and decreased after week 4. In the early period, increases in DC may lead to decreases in SBN. Upon decrease of DC, the SBN may regenerate.


Assuntos
Lentes de Contato Hidrofílicas , Córnea/inervação , Córnea/metabolismo , Células Dendríticas/metabolismo , Síndromes do Olho Seco/metabolismo , Nervo Oftálmico/metabolismo , Feminino , Humanos , Masculino , Microscopia Confocal , Inquéritos e Questionários , Lágrimas/metabolismo , Adulto Jovem
20.
Biochem Biophys Res Commun ; 513(2): 434-438, 2019 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-30967259

RESUMO

High glucose (HG)-induced oxidative stress contributes to the dysfunction of pancreatic ß cells in diabetes. The voltage-gated proton channel Hv1 has been proposed to support reactive oxygen species (ROS) production during respiratory bursts. However, the effect of Hv1 on glucotoxicity in pancreatic ß cells is not clear yet. In this study, we examined the protective effects of Hv1-deficiency in HG cultured ß cells. Following 48 h of treatment with 30 mM high glucose, Hv1 KO ß cells showed higher cell viability, lower cell apoptosis and a more stable insulin gene expression level compared to WT ß cells. In both control and HG cultured ß cells, deficiency of Hv1 decreased the glucose- and PMA-induced ROS production. Finally, HG incubation led to NOX4 upregulation in WT ß cells, which could be inhibited by HV1 deficiency. In conclusion, Hv1-deficiency prevents the HG treatment-induced NOX4 upregulation and protects ß cells from glucotoxicity.


Assuntos
Hiperglicemia/metabolismo , Células Secretoras de Insulina/metabolismo , Canais Iônicos/metabolismo , NADPH Oxidase 4/metabolismo , Estresse Oxidativo , Animais , Apoptose , Células Cultivadas , Técnicas de Inativação de Genes , Glucose/metabolismo , Hiperglicemia/genética , Hiperglicemia/patologia , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/patologia , Canais Iônicos/genética , Camundongos Endogâmicos C57BL , NADPH Oxidase 4/genética , Espécies Reativas de Oxigênio/metabolismo , Regulação para Cima
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