Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 77
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Int J Biol Macromol ; 268(Pt 2): 131908, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38679269

RESUMO

Curcuma longa and Sargassum coreanum are commonly used in traditional pharmaceutical medicine to improve immune function in chronic diseases. The present study was designed to systematically elucidate the in vitro and in vivo immuno-enhancing effects of a combination of C. longa and S. coreanum extracts (CS) that contain polyphenols and saccharides as functional molecules in a cyclophosphamide (Cy)-induced model of immunosuppression. In primary splenocytes, we observed the ameliorative effects of CS on a Cy-induced immunosuppression model with low cytotoxicity and an optimal mixture procedure. CS treatment enhanced T- and B-cell proliferation, increased splenic natural killer-cell activity, and restored cytokine release. Wistar rats were orally administered low (30 mg/kg), intermediate (100 mg/kg), or high (300 mg/kg) doses of CS for four weeks, followed by oral administration of Cy (5 mg/kg) for four weeks. Compared with the vehicle group, low-, intermediate-, and high-dose CS treatment accelerated dose-dependent recovery of the serum level of tumor necrosis factor-α, interferon-γ, interleukin-2, and interleukin-12. These results suggest that CS treatment accelerates the amelioration of immune deficiency in Cy-treated primary splenocytes and rats, which supports considering it for immunity maintenance. Our findings provide experimental evidence for further research and clinical application in immunosuppressed patients.


Assuntos
Células Matadoras Naturais , Polifenóis , Ratos Wistar , Baço , Animais , Polifenóis/farmacologia , Polifenóis/química , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Ratos , Baço/efeitos dos fármacos , Baço/imunologia , Baço/citologia , Citocinas/metabolismo , Masculino , Ciclofosfamida/farmacologia , Proliferação de Células/efeitos dos fármacos , Extratos Vegetais/farmacologia , Extratos Vegetais/química
2.
Metab Eng ; 81: 197-209, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38072356

RESUMO

Ricinoleic acid (C18:1-OH, RA) is a valuable hydroxy fatty acid with versatile applications. The current industrial source of RA relies on the hydrolysis of castor bean oil. However, the coexistence of the toxic compound ricin and the unstable supply of this plant have led to an exploration of promising alternatives: generating RA in heterologous plants or microorganisms. In this study, we engineered the oleaginous yeast Yarrowia lipolytica to produce RA in the form of free fatty acids (FFA). First, we overexpressed fungal Δ12 oleate hydroxylase gene (CpFAH12) from Claviceps purpurea while deleting genes related to fatty acid degradation (MEF1 and PEX10) and oleic acid desaturation (FAD2). Since Δ12 oleate hydroxylase converts oleic acid (C18:1) located at the sn-2 position of phosphatidylcholine (PC), we next focused on increasing the PC pool containing oleic acid. This objective was achieved thorough implementing metabolic engineering strategies designed to enhance the biosynthesis of PC and C18 fatty acids. To increase the PC pool, we redirected the flux towards phospholipid biosynthesis by deleting phosphatidic acid phosphatase genes (PAH1 and APP1) and diacylglycerol acyltransferase gene (DGA1), involved in the production of diacylglycerol and triacylglycerol, respectively. Furthermore, the PC biosynthesis via the CDP-DAG pathway was enhanced through the overexpression of CDS1, PSD1, CHO2, and OPI3 genes. Subsequently, to increase the oleic acid content within PC, we overexpressed the heterologous fatty acid elongase gene (MaC16E) involved in the conversion of C16 to C18 fatty acids. As RA production titer escalated, the produced RA was mainly found in the FFA form, leading to cell growth inhibition. The growth inhibition was mitigated by inducing RA secretion via Triton X-100 treatment, a process that simultaneously amplified RA production by redirecting flux towards RA synthesis. The final engineered strain JHYL-R146 produced 2.061 g/L of free RA in a medium treated with 5% Triton X-100, constituting 74% of the total FFAs produced. Generating free RA offers the added benefit of bypassing the hydrolysis stage required when employing castor bean oil as an RA source. This achievement represents the highest level of RA synthesis from glucose reported thus far, underscoring the potential of Y. lipolytica as a host for sustainable RA production.


Assuntos
Ácidos Graxos não Esterificados , Yarrowia , Ácidos Graxos não Esterificados/genética , Ácidos Graxos não Esterificados/metabolismo , Yarrowia/genética , Yarrowia/metabolismo , Ácido Oleico/genética , Ácido Oleico/metabolismo , Ácidos Ricinoleicos/metabolismo , Octoxinol/metabolismo , Ácidos Graxos/metabolismo , Oxigenases de Função Mista/genética , Engenharia Metabólica
3.
Nat Commun ; 14(1): 8033, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38052830

RESUMO

Endonucleases have recently widely used in molecular diagnostics. Here, we report a strategy to exploit the properties of Argonaute (Ago) proteins for molecular diagnostics by introducing an artificial nucleic acid circuit with Ago protein (ANCA) method. The ANCA is designed to perform a continuous autocatalytic reaction through cross-catalytic cleavage of the Ago protein, enabling one-step, amplification-free, and isothermal DNA detection. Using the ANCA method, carbapenemase-producing Klebsiella pneumoniae (CPKP) are successfully detected without DNA extraction and amplification steps. In addition, we demonstrate the detection of carbapenem-resistant bacteria in human urine and blood samples using the method. We also demonstrate the direct identification of CPKP swabbed from surfaces using the ANCA method in conjunction with a three-dimensional nanopillar structure. Finally, the ANCA method is applied to detect CPKP in rectal swab specimens from infected patients, achieving sensitivity and specificity of 100% and 100%, respectively. The developed method can contribute to simple, rapid and accurate diagnosis of CPKP, which can help prevent nosocomial infections.


Assuntos
Antibacterianos , Ácidos Nucleicos , Humanos , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , beta-Lactamases/genética , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Anticorpos Anticitoplasma de Neutrófilos/metabolismo , Ácidos Nucleicos/metabolismo , Bactérias/genética , DNA/metabolismo , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/metabolismo , Testes de Sensibilidade Microbiana
4.
Commun Chem ; 6(1): 265, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-38057441

RESUMO

The diterpene glycosyltransferase UGT76G1, derived from Stevia rebaudiana, plays a pivotal role in the biosynthesis of rebaudioside A, a natural sugar substitute. Nevertheless, its potential for industrial application is limited by certain enzymatic characteristics, notably thermostability. To enhance the thermostability and enzymatic activity, we employed a computational design strategy, merging stabilizing mutation scanning with a Rosetta-based protein design protocol. Compared to UGT76G1, the designed variant 76_4 exhibited a 9 °C increase in apparent Tm, a 2.55-fold increase rebaudioside A production capacity, and a substantial 11% reduction in the undesirable byproduct rebaudioside I. Variant 76_7 also showed a 1.91-fold enhancement rebaudioside A production capacity, which was maintained up to 55 °C, while the wild-type lost most of its activity. These results underscore the efficacy of structure-based design in introducing multiple mutations simultaneously, which significantly improves the enzymatic properties of UGT76G1. This strategy provides a method for the development of efficient, thermostable enzymes for industrial applications.

5.
Int J Mol Sci ; 24(24)2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38139186

RESUMO

Fisetin is a flavonoid found in plants and has been reported to be effective in various human diseases. However, the effective mechanisms of ultraviolet-A (UVA)-mediated skin damage are not yet clear. In this study, we investigated the protective mechanisms of fisetin regarding UVA-induced human dermal fibroblasts (HDFs) and human epidermal keratinocytes (HEKs) damages. Fisetin showed a cytoprotective effect against UVA irradiation and suppressed matrix metalloproteinases (MMPs), MMP-1, and MMP-3 expression. In addition, fisetin was rescued, which decreased mRNA levels of pro-inflammatory cytokines, reactive oxygen species production, and the downregulation of MAPK/AP-1 related protein and NADPH oxidase (NOX) mRNA levels. Furthermore, UVA-induced MMP-1 and MMP-3 were effectively inhibited by siRNAs to NOX 1 to 5 in HDFs and HEKs. These results indicate that fisetin suppresses UVA-induced damage through the NOX/ROS/MAPK pathway in HDFs and HEKs.


Assuntos
Metaloproteinase 1 da Matriz , Metaloproteinase 3 da Matriz , Humanos , Espécies Reativas de Oxigênio/metabolismo , Metaloproteinase 1 da Matriz/metabolismo , Metaloproteinase 3 da Matriz/genética , Metaloproteinase 3 da Matriz/metabolismo , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Células Cultivadas , Pele/metabolismo , Queratinócitos/metabolismo , Fibroblastos/metabolismo , RNA Mensageiro/metabolismo , Raios Ultravioleta/efeitos adversos
6.
IEEE Trans Knowl Data Eng ; 35(10): 10295-10308, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37954972

RESUMO

In the past decade, many approaches have been suggested to execute ML workloads on a DBMS. However, most of them have looked at in-DBMS ML from a training perspective, whereas ML inference has been largely overlooked. We think that this is an important gap to fill for two main reasons: (1) in the near future, every application will be infused with some sort of ML capability; (2) behind every web page, application, and enterprise there is a DBMS, whereby in-DBMS inference is an appealing solution both for efficiency (e.g., less data movement), performance (e.g., cross-optimizations between relational operators and ML) and governance. In this article, we study whether DBMSs are a good fit for prediction serving. We introduce a technique for translating trained ML pipelines containing both featurizers (e.g., one-hot encoding) and models (e.g., linear and tree-based models) into SQL queries, and we compare in-DBMS performance against popular ML frameworks such as Sklearn and ml.net. Our experiments show that, when pushed inside a DBMS, trained ML pipelines can have performance comparable to ML frameworks in several scenarios, while they perform quite poorly on text featurization and over (even simple) neural networks.

7.
Sci Rep ; 13(1): 16763, 2023 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-37798384

RESUMO

The CRISPR-Cas9 system is a widely used gene-editing tool, offering unprecedented opportunities for treating various diseases. Controlling Cas9/dCas9 activity at specific location and time to avoid undesirable effects is very important. Here, we report a conditionally active CRISPR-Cas9 system that regulates target gene expression upon sensing cellular environmental change. We conjugated the oxygen-sensing transcription activation domain (TAD) of hypoxia-inducing factor (HIF-1α) with the Cas9/dCas9 protein. The Cas9-TAD conjugate significantly increased endogenous target gene cleavage under hypoxic conditions compared with that under normoxic conditions, whereas the dCas9-TAD conjugate upregulated endogenous gene transcription. Furthermore, the conjugate system effectively downregulated the expression of SNAIL, an essential gene in cancer metastasis, and upregulated the expression of the tumour-related genes HNF4 and NEUROD1 under hypoxic conditions. Since hypoxia is closely associated with cancer, the hypoxia-dependent Cas9/dCas9 system is a novel addition to the molecular tool kit that functions in response to cellular signals and has potential application for gene therapeutics.


Assuntos
Sistemas CRISPR-Cas , Neoplasias , Humanos , Sistemas CRISPR-Cas/genética , Regulação da Expressão Gênica , Proteína 9 Associada à CRISPR/genética , Edição de Genes , Hipóxia/genética , Neoplasias/genética
8.
Molecules ; 28(10)2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37241718

RESUMO

Periplasmic α-amylase MalS (EC. 3.2.1.1), which belongs to glycoside hydrolase (GH) family 13 subfamily 19, is an integral component of the maltose utilization pathway in Escherichia coli K12 and used among Ecnterobacteriaceae for the effective utilization of maltodextrin. We present the crystal structure of MalS from E. coli and reveal that it has unique structural features of circularly permutated domains and a possible CBM69. The conventional C-domain of amylase consists of amino acids 120-180 (N-terminal) and 646-676 (C-terminal) in MalS, and the whole domain architecture shows the complete circular permutation of C-A-B-A-C in domain order. Regarding substrate interaction, the enzyme has a 6-glucosyl unit pocket binding it to the non-reducing end of the cleavage site. Our study found that residues D385 and F367 play important roles in the preference of MalS for maltohexaose as an initial product. At the active site of MalS, ß-CD binds more weakly than the linear substrate, possibly due to the positioning of A402. MalS has two Ca2+ binding sites that contribute significantly to the thermostability of the enzyme. Intriguingly, the study found that MalS exhibits a high binding affinity for polysaccharides such as glycogen and amylopectin. The N domain, of which the electron density map was not observed, was predicted to be CBM69 by AlphaFold2 and might have a binding site for the polysaccharides. Structural analysis of MalS provides new insight into the structure-evolution relationship in GH13 subfamily 19 enzymes and a molecular basis for understanding the details of catalytic function and substrate binding of MalS.


Assuntos
Glicosídeo Hidrolases , alfa-Amilases , alfa-Amilases/metabolismo , Glicosídeo Hidrolases/metabolismo , Escherichia coli/metabolismo , Sequência de Aminoácidos , Amilases/metabolismo , Especificidade por Substrato , Cristalografia por Raios X
9.
Molecules ; 28(8)2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37110788

RESUMO

In this study, we aimed to develop natural and/or functional materials with antioxidant and anti-inflammatory effects. We obtained extracts from natural plants through an oil and hot-water extraction process and prepared an extract composite of an effective unsaturated fatty acid complex (EUFOC). Furthermore, the antioxidant effect of the extract complex was evaluated, and the anti-inflammatory effect was explored by assessing its inhibitory effect on nitric oxide production through its HA-promoting effect. We conducted a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay to evaluate the cell viability of the EUFOC, and the results showed that EUFOC was not cytotoxic at the test concentrations. In addition, it showed no endogenous cytotoxicity in HaCaT (human keratinocyte) cells. The EUFOC showed excellent 1,1-diphenyl-2-picrylhydrazyl- and superoxide-scavenging abilities. Moreover, it exerted an inhibitory effect on NO production at concentrations that did not inhibit cell viability. The secretion of all the cytokines was increased by lipopolysaccharide (LPS) treatment; however, this was inhibited by the EUFOC in a concentration-dependent manner. In addition, hyaluronic acid content was markedly increased by the EUFOC in a dose-dependent manner. These results suggest that the EUFOC has excellent anti-inflammatory and antioxidant properties, and hence, it can be used as a functional material in various fields.


Assuntos
Antioxidantes , Ácido Hialurônico , Humanos , Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Óxido Nítrico/metabolismo , Anti-Inflamatórios/farmacologia , Citocinas
11.
Materials (Basel) ; 17(1)2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38203897

RESUMO

It is difficult to obtain ultrathin two-dimensional (2D) tungsten trioxide (WO3) nanosheets through direct exfoliation from bulk WO3 in solution due to the strong bonding between interlayers. Herein, WO3 nanosheets with controllable sizes were synthesized via K+ intercalation and the exfoliation of WO3 powder using sonication and temperature. Because of the intercalation and expansion in the interlayer distance, the intercalated WO3 could be successfully exfoliated to produce a large quantity of individual 2D WO3 nanosheets in N-methyl-2-pyrrolidone under sonication. The exfoliated ultrathin WO3 nanosheets exhibited better electrochromic performance in an electrochromic device than WO3 powder and exfoliated WO3 without intercalation. In particular, the prepared small WO3 nanosheets exhibited excellent electrochromic properties with a large optical modulation of 41.78% at 700 nm and fast switching behavior times of 9.2 s for bleaching and 10.5 s for coloring. Furthermore, after 1000 cycles, the small WO3 nanosheets still maintained 86% of their initial performance.

12.
Front Bioeng Biotechnol ; 10: 995238, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36159701

RESUMO

Flavonoid aglycones possess biological activities, such as antioxidant and antidiabetic activities compared to glycosides. Taxifolin, a flavonoid aglycones, is detected only in trace amounts in nature and is not easily observed. Therefore, in this study, to investigate the hair tonic and hair loss inhibitors effect of taxifolin, high content of taxifolin aglycone extract was prepared by enzymatic hydrolysis. Taxifolin effectively regulates the apoptosis of dermal papilla cells, which is associated with hair loss, based on its strong antioxidant activities. However, inhibition of dihydrotestosterone (DHT), which is a major cause of male pattern hair loss, was significantly reduced with taxifolin treatment compared with minoxidil, as a positive control. It was also confirmed that a representative factor for promoting hair growth, IGF-1, was significantly increased, and that TGF-ß1, a representative biomarker for hair loss, was significantly reduced with taxifolin treatment. These results suggest that taxifolin from enzymatic hydrolysis of RM is a potential treatment for hair loss and a hair growth enhancer.

13.
Nat Chem Biol ; 18(9): 1005-1013, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35915259

RESUMO

Transposon-associated transposase B (TnpB) is deemed an ancestral protein for type V, Cas12 family members, and the closest ancestor to UnCas12f1. Previously, we reported a set of engineered guide RNAs supporting high indel efficiency for Cas12f1 in human cells. Here we suggest a new technology whereby the engineered guide RNAs also manifest high-efficiency programmable endonuclease activity for TnpB. We have termed this technology TaRGET (TnpB-augment RNA-based Genome Editing Technology). Having this feature in mind, we established TnpB-based adenine base editors (ABEs). A Tad-Tad mutant (V106W, D108Q) dimer fused to the C terminus of dTnpB (D354A) showed the highest levels of A-to-G conversion. The limited targetable sites for TaRGET-ABE were expanded with engineered variants of TnpB or optimized deaminases. Delivery of TaRGET-ABE also ensured potent A-to-G conversion rates in mammalian genomes. Collectively, the TaRGET-ABE will contribute to improving precise genome-editing tools that can be delivered by adeno-associated viruses, thereby harnessing the development of clustered regularly interspaced short palindromic repeats (CRISPR)-based gene therapy.


Assuntos
Adenina , RNA , Adenina/metabolismo , Animais , Sistemas CRISPR-Cas/genética , Edição de Genes , Humanos , Mamíferos/genética , RNA/genética , RNA/metabolismo , RNA Guia de Cinetoplastídeos/genética , RNA Guia de Cinetoplastídeos/metabolismo , Transposases/genética , Transposases/metabolismo
14.
Biosens Bioelectron ; 209: 114256, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35430408

RESUMO

In this study, we uncover a ligation-free DNA extension method in two adjacent fragmented probes, which are hybridized to target RNA, for developing a ligation-free nucleic acid amplification reaction. In this reaction, DNA elongation occurs from a forward probe to a phosphorothioated-hairpin probe in the presence of target RNA regardless of ligation. The second DNA elongation then occurs simultaneously at the nick site of the phosphorothioated probe and the self-priming region. Therefore, the binding site of the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) 12a is repeatedly amplified, inducing a fluorescence signal in the presence of CRISPR-Cas12a. This ligation-free isothermal gene amplification method enables the detection of target RNA with 49.2 fM sensitivity. Moreover, two types of mRNA detection are feasible, thus, demonstrating the potential of this method for cancer companion diagnostics. Notably, the proposed method also demonstrates efficacy when applied for the detection of mRNA extracted from human cells and tumor-bearing mouse tissue and urine samples. Hence, this newly developed ligation-free isothermal nucleic acid amplification system is expected to be widely used in a variety of gene detection platforms.


Assuntos
Técnicas Biossensoriais , Sistemas CRISPR-Cas , Animais , Técnicas Biossensoriais/métodos , Sistemas CRISPR-Cas/genética , DNA/genética , Camundongos , Técnicas de Amplificação de Ácido Nucleico/métodos , RNA , RNA Mensageiro
15.
Molecules ; 27(6)2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35335156

RESUMO

In this paper, we studied the effects of the intersection angle between the inlet channels on the droplet diameter using a COMSOL Multiphysics® simulation. We employed the level-set method to study the droplet generation process inside a microfluidic flow device. A flow-focusing geometry was integrated into a microfluidics device and used to study droplet formation in liquid-liquid systems. Droplets formed by this flow-focusing technique are typically smaller than the upstream capillary tube and vary in size with the flow rates. Different intersection angles were modeled with a fixed width of continuous and dispersed channels, orifices, and expansion channels. Numerical simulations were performed using the incompressible Navier-Stokes equations for single-phase flow in various flow-focusing geometries. As a result of modeling, when the dispersed flow rate and the continuous flow rate were increased, the flow of the continuous flow fluid interfered with the flow of the dispersed flow fluid, which resulted in a decrease in the droplet diameter. Variations in the droplet diameter can be used to change the intersection angle and fluid flow rate. In addition, it was predicted that the smallest diameter droplet would be generated when the intersection angle was 90°.


Assuntos
Técnicas Analíticas Microfluídicas , Simulação por Computador , Dispositivos Lab-On-A-Chip
16.
Molecules ; 27(4)2022 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-35209192

RESUMO

The purpose of this study was to identify the characteristics of blood flow in aortic coarctation based on stenotic shape structure, stenosis rate, and the distribution of the wall load delivered into the blood vessels and to predict the impact on aneurysm formation and rupture of blood vessels by using a computational fluid dynamics modeling method. It was applied on the blood flow in abdominal aortic blood vessels in which stenosis occurred by using the commercial finite element software ADINA on fluid-solid interactions. The results of modeling, with an increasing stenosis rate and Reynolds number, showed the pressure drop was increased and the velocity was greatly changed. When the stenosis rate was the same, the pressure drop and the velocity change were larger in the stenosis with a symmetric structure than in the stenosis with an asymmetric one. Maximal changes in wall shear stress were observed in the area before stenosis and minimal changes were shown in stenosis areas. The minimal shear stress occurred at different locations depending on the stenosis shape models. With an increasing stenosis rate and Reynolds number, the maximal wall shear stress was increased and the minimal wall shear stress was decreased. Through such studies, it is thought that the characteristics of blood flow in the abdominal aorta where a stenosis is formed will be helpful in understanding the mechanism of growth of atherosclerosis and the occurrence and rupture of the abdominal aortic flow.


Assuntos
Coartação Aórtica/diagnóstico , Coartação Aórtica/fisiopatologia , Hemodinâmica , Modelos Cardiovasculares , Estresse Mecânico , Algoritmos , Aorta/anormalidades , Aorta/diagnóstico por imagem , Aorta/fisiopatologia , Velocidade do Fluxo Sanguíneo , Humanos
17.
Molecules ; 27(4)2022 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-35209207

RESUMO

This study was conducted to examine the anti-hair loss mechanism of the supercritical fluid extraction-residues extract of Ulmus davidiana by the regulation of cytokine production and hormone function in human dermal follicle papilla cells (HDFPCs). To investigate the modulatory effects on H2O2-induced cytokines, we measured transforming growth factor-beta and insulin-like growth factor 1 secreted from HDFPCs. To investigate the regulatory effects of supercritical extraction-residues extract of Ulmus davidiana on dihydrotestosterone hormone production, cells were co-incubated with high concentrations of testosterone. The supercritical extraction-residues extract of Ulmus davidiana significantly inhibited the secretion of transforming growth factor-beta but rescued insulin-like growth factor 1 in a dose-dependent manner. The supercritical extraction-residues extract of Ulmus davidiana markedly reduced dihydrotestosterone production. These results suggest that the supercritical fluid extract residues of Ulmus davidiana and their functional molecules are candidates for preventing human hair loss.


Assuntos
Citocinas/metabolismo , Di-Hidrotestosterona/metabolismo , Folículo Piloso/metabolismo , Casca de Planta/química , Extratos Vegetais/farmacologia , Ulmus/química , Humanos , Extratos Vegetais/química
18.
Biochem Biophys Res Commun ; 586: 49-54, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34826700

RESUMO

Maltodextrin glucosidase (MalZ) is a key enzyme in the maltose utilization pathway in Escherichia coli that liberates glucose from the reducing end of the short malto-oligosaccharides. Unlike other enzymes in the GH13_21 subfamily, the hydrolytic activity of MalZ is limited to maltodextrin rather than long starch substrates, forming various transglycosylation products in α-1,3, α-1,4 or α-1,6 linkages. The mechanism for the substrate binding and hydrolysis of this enzyme is not well understood yet. Here, we present the dimeric crystal structure of MalZ, with the N-domain generating a unique substrate binding groove. The N-domain bears CBM34 architecture and forms a part of the active site in the catalytic domain of the adjacent molecule. The groove found between the N-domain and catalytic domain from the adjacent molecule, shapes active sites suitable for short malto-oligosaccharides, but hinders long stretches of oligosaccharides. The conserved residue of E44 protrudes at subsite +2, elucidating the hydrolysis pattern of the substrate by the glucose unit from the reducing end. The structural analysis provides a molecular basis for the substrate specificity and the enzymatic property, and has potential industrial application for protein engineering.


Assuntos
Proteínas de Escherichia coli/química , Escherichia coli/enzimologia , Glucose/química , Glicosídeo Hidrolases/química , Polissacarídeos/química , Biocatálise , Domínio Catalítico , Clonagem Molecular , Cristalografia por Raios X , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Glucose/metabolismo , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Hidrólise , Modelos Moleculares , Polissacarídeos/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade por Substrato
19.
Biosensors (Basel) ; 11(9)2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34562891

RESUMO

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease-19 (COVID-19), has severely influenced public health and economics. For the detection of SARS-CoV-2, clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR associated protein (Cas)-based assays have been emerged because of their simplicity, sensitivity, specificity, and wide applicability. Herein, we have developed a CRISPR-Cas12-based assay for the detection of SARS-CoV-2. In the assay, the target amplicons are produced by isothermal reverse transcription recombinase polymerase amplification (RT-RPA) and recognized by a CRISPR-Cas12a/guide RNA (gRNA) complex that is coupled with the collateral cleavage activity of fluorophore-tagged probes, allowing either a fluorescent measurement or naked-eye detection on a lateral flow paper strip. This assay enables the sensitive detection of SARS-CoV-2 at a low concentration of 10 copies per sample. Moreover, the reliability of the method is verified by using nasal swabs and sputum of COVID-19 patients. We also proved that the current assay can be applied to other viruses, such as Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus (SARS-CoV), with no major changes to the basic scheme of testing. It is anticipated that the CRISPR-Cas12-based assay has the potential to serve as a point-of-care testing (POCT) tool for a wide range of infectious viruses.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas Associadas a CRISPR/metabolismo , Endodesoxirribonucleases/metabolismo , Coronavírus da Síndrome Respiratória do Oriente Médio/isolamento & purificação , SARS-CoV-2/isolamento & purificação , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/isolamento & purificação , Viroses/diagnóstico , Sistemas CRISPR-Cas , Corantes Fluorescentes/química , Humanos , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Nariz/virologia , Testes Imediatos , RNA Guia de Cinetoplastídeos/química , RNA Guia de Cinetoplastídeos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , SARS-CoV-2/genética , Sensibilidade e Especificidade , Escarro/virologia
20.
Front Bioeng Biotechnol ; 9: 673314, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34169066

RESUMO

Alnus sibirica Fisch. ex Turcz (ASFT), belonging to the family of Betulaceae, grows naturally in Asia, Europe, and America. The aims of this study are determining the efficacy of various biomarkers related to hair loss, evaluated by extracting the branch with 60% alcohol, and purely separating diarylheptanoid oregonin, an indicator and active substance, from 60% alcohol extract of the tree. To determine the preventive effects on hair loss, we investigated the anti-oxidative and anti-apoptotic effects on hydrogen peroxide-induced cytotoxicity on human hair dermal papilla cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and Western blotting analysis for proving of apoptosis-related marker alteration, respectively. Moreover, we examined the ameliorative effects of 60% alcohol extract of the tree and oregonin against changes of oxidative stress-induced cytokine and testosterone-induced dihydrotestosterone production as crucial pathways of the hair loss mechanism. These results suggest that 60% alcohol extract of the tree and oregonin were available as novel natural materials for maintaining hair health in mammals.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...