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1.
Cell Biol Toxicol ; 40(1): 31, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38767771

RESUMEN

Mitochondrial dysfunction contributes to cerebral ischemia-reperfusion (CI/R) injury, which can be ameliorated by Sirtuin-3 (SIRT3). Under stress conditions, the SIRT3-promoted mitochondrial functional recovery depends on both its activity and expression. However, the approach to enhance SIRT3 activity after CI/R injury remains unelucidated. In this study, Sprague-Dawley (SD) rats were intracranially injected with either adeno-associated viral Sirtuin-1 (AAV-SIRT1) or AAV-sh_SIRT1 before undergoing transient middle cerebral artery occlusion (tMCAO). Primary cortical neurons were cultured and transfected with lentiviral SIRT1 (LV-SIRT1) and LV-sh_SIRT1 respectively before oxygen-glucose deprivation/reoxygenation (OGD/R). Afterwards, rats and neurons were respectively treated with a selective SIRT3 inhibitor, 3-(1H-1,2,3-triazol-4-yl) pyridine (3-TYP). The expression, function, and related mechanism of SIRT1 were investigated by Western Blot, flow cytometry, immunofluorescence staining, etc. After CI/R injury, SIRT1 expression decreased in vivo and in vitro. The simulation and immune-analyses reported strong interaction between SIRT1 and SIRT3 in the cerebral mitochondria before and after CI/R. SIRT1 overexpression enhanced SIRT3 activity by increasing the deacetylation of SIRT3, which ameliorated CI/R-induced cerebral infarction, neuronal apoptosis, oxidative stress, neurological and motor dysfunction, and mitochondrial respiratory chain dysfunction, promoted mitochondrial biogenesis, and retained mitochondrial integrity and mitochondrial morphology. Meanwhile, SIRT1 overexpression alleviated OGD/R-induced neuronal death and mitochondrial bioenergetic deficits. These effects were reversed by AAV-sh_SIRT1 and the neuroprotective effects of SIRT1 were partially offset by 3-TYP. These results suggest that SIRT1 restores the structure and function of mitochondria by activating SIRT3, offering neuroprotection against CI/R injury, which signifies a potential approach for the clinical management of cerebral ischemia.


Asunto(s)
Isquemia Encefálica , Mitocondrias , Neuronas , Ratas Sprague-Dawley , Daño por Reperfusión , Sirtuina 1 , Sirtuina 3 , Animales , Sirtuina 1/metabolismo , Sirtuina 1/genética , Daño por Reperfusión/metabolismo , Daño por Reperfusión/patología , Mitocondrias/metabolismo , Masculino , Sirtuina 3/metabolismo , Sirtuina 3/genética , Neuronas/metabolismo , Neuronas/patología , Ratas , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patología , Infarto de la Arteria Cerebral Media/metabolismo , Infarto de la Arteria Cerebral Media/patología , Apoptosis , Sirtuinas
2.
Bioorg Chem ; 147: 107317, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38583252

RESUMEN

By inducing steric activation of the 10CH bond with a 12-acyl group to form a key imine oxime intermediate, 20 novel (10S)-10,12-disubstituted aloperine derivatives were successfully synthesized and assessed for their antiviral efficacy against HCoV-OC43. Of them, compound 3i exhibited the moderate activities against HCoV-OC43, as well as against the SARS-CoV-2 variant EG.5.1 with the comparable EC50 values of 4.7 and 4.1 µM. A mechanism study revealed that it inhibited the protease activity of host TMPRSS2 by binding to an allosteric site, rather than the known catalytic center, different from that of camostat. Also, the combination of compound 3i and molnupiravir, as an RdRp inhibitor, showed an additive antiviral effect against HCoV-OC43. The results provide a new binding mode and lead compound for targeting TMPRSS2, with an advantage in combating broad-spectrum coronavirus.


Asunto(s)
Sitio Alostérico , Antivirales , Coronavirus Humano OC43 , Quinolizidinas , Serina Endopeptidasas , Antivirales/farmacología , Antivirales/química , Antivirales/síntesis química , Serina Endopeptidasas/metabolismo , Humanos , Coronavirus Humano OC43/efectos de los fármacos , Coronavirus Humano OC43/química , Quinolizidinas/química , Quinolizidinas/farmacología , Quinolizidinas/síntesis química , Sitio Alostérico/efectos de los fármacos , Relación Estructura-Actividad , Descubrimiento de Drogas , SARS-CoV-2/efectos de los fármacos , Estructura Molecular , Pruebas de Sensibilidad Microbiana , Relación Dosis-Respuesta a Droga
3.
J Transl Med ; 22(1): 283, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38491378

RESUMEN

The activation of glycolysis, particularly in the context of reprogrammed energy metabolism, is increasingly recognized as a significant characteristic of cancer. However, the precise mechanisms by which glycolysis is promoted in metastatic gastric cancer cells under normal oxygen conditions remain poorly understood. MicroRNAs (miRNAs) play a crucial role in the development of malignant phenotypes in gastric cancer. Nevertheless, our understanding of the specific involvement of miRNAs in hypoxia-induced metabolic shifting and the subsequent metastatic processes is limited. Hypoxia-induced downregulation of miR-598-3p mechanistically leads to the upregulation of RMP and IGF1r, thereby promoting glycolysis. Either overexpression of miR-598-3p or R406 treatment effectively suppresses the metastasis of gastric cancer cells both in vitro and in vivo. Collectively, the depletion of miR-598-3p alters glucose metabolism from oxidative phosphorylation to glycolysis, thereby exacerbating the malignancy of gastric cancer cells. The present findings indicate a potential target for the development of therapeutics against gastric cancers with increased miR-598-3p expression.


Asunto(s)
MicroARNs , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , MicroARNs/metabolismo , Hipoxia/genética , Glucólisis/genética , Proliferación Celular/genética , Línea Celular Tumoral
4.
Eur J Med Chem ; 264: 115978, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38061229

RESUMEN

The COVID-19 pandemic highlights the urgent need to develop effective small-molecule antivirals. Thirty-three novel biaryl amide derivatives were synthesized and evaluated for anti-coronaviral activity. Some significant SARs were uncovered and the intensive structure modifications led to the most active compounds 8b and 8h. The broad-spectrum anti-coronaviral effects of 8h were validated at RNA and protein levels. 8h inhibits coronavirus replication at multiple stages, from virus entry to virus dsRNA synthesis. The mechanism of action showed that 8h may simultaneously act on 3CLpro and TMPRSS2 to display anti-coronaviral effects. 8h combined with RdRp inhibitor showed synergistic inhibitory activity against coronavirus. This study confirmed that biaryl amide derivatives may be a new class of potential therapeutic agents against coronavirus with multiple target effect, worthy of further investigation.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Amidas/farmacología , Pandemias , Antivirales/química , Inhibidores de Proteasas/farmacología
5.
Sci Rep ; 13(1): 21949, 2023 12 11.
Artículo en Inglés | MEDLINE | ID: mdl-38081892

RESUMEN

Supraglottic jet oxygenation/ventilation (SJOV) can reduce hypoxemia in sedated endoscopy but may increase minor side effects like pharyngalgia and xerostomia. This study aimed to identify risk factors for pharyngalgia/xerostomia with SJOV during gastrointestinal endoscopy. From January 1 to December 31, 2021, 5313 patients with propofol sedation and SJOV underwent gastrointestinal endoscopy or removal of gastrointestinal polyps was analyzed retrospectively. Data included patient characteristics, operation details, postoperative adverse events, and potential risk factors for postoperative adverse events. Parameters considered as potential risk factors were identified based on study results published previously and based on the researcher's idea and clinical experience. The patient factors and the incidence of pharyngalgia/xerostomia at 30 min post-procedure were assessed. Descriptive statistics were calculated using SPSS software. Evaluation potential risk factors using univariate and multivariate logistic regression. Pharyngalgia/xerostomia occurred in 18.7% of patients at 30 min after procedure. A multivariable analysis showed that procedure time and pharyngalgia/xerostomia within 2 weeks were independent risk factors. Procedure time had the strongest association with postoperative pharyngalgia/xerostomia (OR, 8.09 [95% CI, 4.197-6.312]). No factors were significantly associated with hypoxemia risk (1.7% incidence). There were no barotrauma or other serious morbidity or mortality. Procedure duration and recent pharyngalgia/xerostomia increased risk of pharyngalgia/xerostomia with SJOV during endoscopy. Limiting SJOV duration may reduce side effects in susceptible patients. No predictors of hypoxemia were identified.


Asunto(s)
Faringitis , Propofol , Humanos , Estudios Retrospectivos , Endoscopía Gastrointestinal , Factores de Riesgo , Hipoxia/etiología
6.
Front Microbiol ; 14: 1255716, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37744931

RESUMEN

It is vital to diagnose pathogens quickly and effectively in the research and treatment of disease. Argonaute (Ago) proteins are recently discovered nucleases with nucleic acid shearing activity that exhibit specific recognition properties beyond CRISPR-Cas nucleases, which are highly researched but restricted PAM sequence recognition. Therefore, research on Ago protein-mediated nucleic acid detection technology has attracted significant attention from researchers in recent years. Using Ago proteins in developing nucleic acid detection platforms can enable efficient, convenient, and rapid nucleic acid detection and pathogen diagnosis, which is of great importance for human life and health and technological development. In this article, we introduce the structure and function of Argonaute proteins and discuss the latest advances in their use in nucleic acid detection.

7.
RSC Adv ; 13(27): 18953-18959, 2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37350861

RESUMEN

Chiral motifs of 2,3-dihydro-1,4 benzodioxane are extensively utilized in diverse medicinal substances and bioactive natural compounds, exhibiting significant biological activities. Notable examples of such therapeutic agents include prosympal, dibozane, piperoxan, and doxazosin. In this work, using 1,4-benzodioxane-2-carboxylic acid methyl ester as the substrate, after screening 38 CALB covariant residues, we found that mutants A225F and A225F/T103A can catalyze the kinetic resolution of the substrate. The effect of temperature, cosolvent, and cosolvent concentration on kinetic resolution was investigated, revealing that the best results were achieved at 30 °C with 20% n-butanol as a cosolvent, resulting in an optimal resolution (e.e.s 97%, E = 278) at 50 mM substrate concentration. Structure analysis showed that mutation sites 225 and 103 are not among the sites that interact directly with the substrate, which means that covariant amino acids that interact remotely with the substrate also regulate enzyme catalysis. This research may provide us with a new strategy for enzyme evolution.

8.
J Transl Med ; 21(1): 297, 2023 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-37138283

RESUMEN

OBJECTIVES: Available literature documents that ischemic stroke can disrupt the morphology and function of mitochondria and that the latter in other disease models can be preserved by neuropilin-1 (NRP-1) via oxidative stress suppression. However, whether NRP-1 can repair mitochondrial structure and promote functional recovery after cerebral ischemia is still unknown. This study tackled this very issue and explored the underlying mechanism. METHODS: Adeno-associated viral (AAV)-NRP-1 was stereotaxically inoculated into the cortex and ipsilateral striatum posterior of adult male Sprague-Dawley (SD) rats before a 90-min transient middle cerebral artery occlusion (tMCAO) and subsequent reperfusion. Lentivirus (LV)-NRP-1 was transfected into rat primary cortical neuronal cultures before a 2-h oxygen-glucose deprivation and reoxygenation (OGD/R) injury to neurons. The expression and function of NRP-1 and its specific protective mechanism were investigated by Western Blot, immunofluorescence staining, flow cytometry, magnetic resonance imaging, transmission electron microscopy, etc. The binding was detected by molecular docking and molecular dynamics simulation. RESULTS: Both in vitro and in vivo models of cerebral ischemia/reperfusion (I/R) injury presented a sharp increase in NRP-1 expression. The expression of AAV-NRP-1 markedly ameliorated the cerebral I/R-induced damage to the motor function and restored the mitochondrial morphology. The expression of LV-NRP-1 alleviated mitochondrial oxidative stress and bioenergetic deficits. AAV-NRP-1 and LV-NRP-1 treatments increased the wingless integration (Wnt)-associated signals and ß-catenin nuclear localization. The protective effects of NRP-1 were reversed by the administration of XAV-939. CONCLUSIONS: NRP-1 can produce neuroprotective effects against I/R injury to the brain by activating the Wnt/ß-catenin signaling pathway and promoting mitochondrial structural repair and functional recovery, which may serve as a promising candidate target in treating ischemic stroke.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Fármacos Neuroprotectores , Daño por Reperfusión , Ratas , Animales , Masculino , Ratas Sprague-Dawley , Neuropilina-1 , Simulación del Acoplamiento Molecular , Daño por Reperfusión/patología , Isquemia Encefálica/complicaciones , Isquemia Encefálica/metabolismo , Infarto de la Arteria Cerebral Media/complicaciones , Infarto de la Arteria Cerebral Media/patología , Mitocondrias/metabolismo , Apoptosis
9.
Adv Sci (Weinh) ; 10(19): e2207174, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37096843

RESUMEN

MXenes emerging as an amazing class of 2D layered materials, have drawn great attention in the past decade. Recent progress suggest that MXene-based materials have been widely explored as conductive electrodes for printed electronics, including electronic and optoelectronic devices, sensors, and energy storage systems. Here, the critical factors impacting device performance are comprehensively interpreted from the viewpoint of contact engineering, thereby giving a deep understanding of surface microstructures, contact defects, and energy level matching as well as their interaction principles. This review also summarizes the existing challenges of MXene inks and the related printing techniques, aiming at inspiring researchers to develop novel large-area and high-resolution printing integration methods. Moreover, to effectually tune the states of contact interface and meet the urgent demands of printed electronics, the significance of MXene contact engineering in reducing defects, matching energy levels, and regulating performance is highlighted. Finally, the printed electronics constructed by the collaborative combination of the printing process and contact engineering are discussed.

10.
Front Plant Sci ; 13: 1009630, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36247579

RESUMEN

During the growth season, jujube trees are susceptible to infestation by the leaf mite, which reduces the fruit quality and productivity. Traditional monitoring techniques for mites are time-consuming, difficult, subjective, and result in a time lag. In this study, the method based on a particle swarm optimization (PSO) algorithm extreme learning machine for estimation of leaf chlorophyll content (SPAD) under leaf mite infestation in jujube was proposed. Initially, image data and SPAD values for jujube orchards under four severities of leaf mite infestation were collected for analysis. Six vegetation indices and SPAD value were chosen for correlation analysis to establish the estimation model for SPAD and the vegetation indices. To address the influence of colinearity between spectral bands, the feature band with the highest correlation coefficient was retrieved first using the successive projection algorithm. In the modeling process, the PSO correlation coefficient was initialized with the convergent optimal approximation of the fitness function value; the root mean square error (RMSE) of the predicted and measured values was derived as an indicator of PSO goodness-of-fit to solve the problems of ELM model weights, threshold randomness, and uncertainty of network parameters; and finally, an iterative update method was used to determine the particle fitness value to optimize the minimum error or iteration number. The results reflected that significant differences were observed in the spectral reflectance of the jujube canopy corresponding with the severity of leaf mite infestation, and the infestation severity was negatively correlated with the SPAD value of jujube leaves. The selected vegetation indices NDVI, RVI, PhRI, and MCARI were positively correlated with SPAD, whereas TCARI and GI were negatively correlated with SPAD. The accuracy of the optimized PSO-ELM model (R 2 = 0.856, RMSE = 0.796) was superior to that of the ELM model alone (R 2 = 0.748, RMSE = 1.689). The PSO-ELM model for remote sensing estimation of relative leaf chlorophyll content of jujube shows high fault tolerance and improved data-processing efficiency. The results provide a reference for the utility of UAV remote sensing for monitoring leaf mite infestation of jujube.

11.
Phytomedicine ; 107: 154454, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36155218

RESUMEN

BACKGROUND: Colorectal cancer is associated with ulcerative colitis (UC). The infiltration of neutrophils is the main cause of DNA damage produced by inflammation in the intestinal epithelium. Under the action of peptidyl arginine deaminase 4 (PAD4), neutrophils dissociate chromatin and form neutrophil extracellular traps (NETs), which can aggravate tissue inflammation and encourage tumor development. Although Huang Qin Decoction (HQD) was found to be useful in treating UC and was used to gradually prevent and treat digestive tract cancers, the underlying reasons were unclear. METHODS: To demonstrate HQD could inhibits the initiation of colitis associated carcinogenesis by controlling NETs related inflammation, we first performed an AOM/DSS-generated colitis-associated carcinogenesis model to assess the efficacy of HQD in reducing neutrophil infiltration and anti-tumor activity. Then, using network pharmacology research, we investigated the potential mechanisms underlying those medicinal effects, as demonstrated by the detection of NETs aggregation and PAD4 expression changes in the colon. RESULTS: HQD substantially reduced the number of colon cancers and the expression of Ki67, restored the level of intestinal tight junction protein occludin and ZO-1, and relieved the intestinal inflammation caused by TNF-α, IL-1ß. At the same time, it inhibited neutrophil infiltration in the colon and improved the immunosurveillance of CD8+T cells. The potential mechanisms of HQD intervention against UC and UC with neoplasia (UCN) were studied using network pharmacology, and 156 conjunct genes as well as numerous inflammation-related pathways were identified. Protein-protein interaction (PPI) analysis indicated that HQD inhibition of intestinal tumors might be related to the deactivation of PAD4, which was verified by the down-regulation of NETs, MPO-DNA complex levels, and PAD4 expression after HQD treatment. CONCLUSION: Huang Qin Decoction inhibits the initiation of colitis associated carcinogenesis by controlling PAD4-dependent neutrophil extracellular traps.


Asunto(s)
Colitis Ulcerosa , Colitis , Trampas Extracelulares , Animales , Arginina/metabolismo , Carcinogénesis , Cromatina/metabolismo , Colitis/inducido químicamente , Colitis/complicaciones , Colitis/tratamiento farmacológico , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/tratamiento farmacológico , Modelos Animales de Enfermedad , Trampas Extracelulares/metabolismo , Humanos , Inflamación/metabolismo , Antígeno Ki-67/metabolismo , Ratones , Ratones Endogámicos C57BL , Ocludina/metabolismo , Scutellaria baicalensis , Factor de Necrosis Tumoral alfa/metabolismo
12.
Acta Pharmacol Sin ; 43(6): 1495-1507, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34671110

RESUMEN

Ulcerative colitis (UC) is a chronic inflammatory disease of the gastrointestinal tract, which is closely related to gut barrier dysfunction. Emerging evidence shows that interleukin-22 (IL-22) derived from group 3 innate lymphoid cells (ILC3s) confers benefits on intestinal barrier, and IL-22 expression is controlled by aryl hydrocarbon receptor (AhR). Previous studies show that baicalein protects the colon from inflammatory damage. In this study we elucidated the molecular mechanisms underlying the protective effect of baicalein on intestinal barrier function in colitis mice. Mice were administered baicalein (10, 20, 40 mg·kg-1·d-1, i.g.) for 10 days; the mice freely drank 3% dextran sulfate sodium (DSS) on D1-D7 to induce colitis. We showed that baicalein administration simultaneously ameliorated gut inflammation, decreased intestinal permeability, restored tight junctions of colons possibly via promoting AhR/IL-22 pathway. Co-administration of AhR antagonist CH223191 (10 mg/kg, i.p.) partially blocked the therapeutic effects of baicalein in colitis mice, whereas AhR agonist FICZ (1 µg, i.p.) ameliorated symptoms and gut barrier function in colitis mice. In a murine lymphocyte line MNK-3, baicalein (5-20 µM) dose-dependently increased the expression of AhR downstream target protein CYP1A1, and enhanced IL-22 production through facilitating AhR nuclear translocation, these effects were greatly diminished in shAhR-MNK3 cells, suggesting that baicalein induced IL-22 production in AhR-dependent manner. To further clarify that, we constructed an in vitro system consisting of MNK-3 and Caco-2 cells, in which MNK-3 cell supernatant treated with baicalein could decrease FITC-dextran permeability and promoted the expression of tight junction proteins ZO-1 and occluding in Caco-2 cells. In conclusion, this study demonstrates that baicalein ameliorates colitis by improving intestinal epithelial barrier via AhR/IL-22 pathway in ILC3s, thus providing a potential therapy for UC.


Asunto(s)
Colitis Ulcerosa , Colitis , Animales , Células CACO-2 , Colitis/metabolismo , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/tratamiento farmacológico , Colitis Ulcerosa/metabolismo , Colon/metabolismo , Sulfato de Dextran/toxicidad , Modelos Animales de Enfermedad , Flavanonas , Humanos , Inmunidad Innata , Interleucinas , Mucosa Intestinal/metabolismo , Linfocitos , Ratones , Ratones Endogámicos C57BL , Receptores de Hidrocarburo de Aril/metabolismo , Receptores de Hidrocarburo de Aril/uso terapéutico , Interleucina-22
13.
Eur J Anaesthesiol ; 38(3): 294-301, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33234777

RESUMEN

BACKGROUND: Hypoxaemia is frequently seen during flexible bronchoscopies that are done with a nasal approach under the traditional sedation with propofol. This study investigated the potential benefits of supraglottic jet oxygenation and ventilation (SJOV) using the Wei nasal jet tube (WNJ) in reducing hypoxaemia in patients undergoing bronchoscopy under moderate to deep intravenous sedation using a propofol, lidocaine and remifentanil cocktail. OBJECTIVES: Our primary objective was to evaluate the efficacy and complications of SJOV via the WNJ during flexible bronchoscopy under moderate to heavy sedation with propofol and remifentanil. DESIGN: A randomised controlled clinical trial. SETTING: The 180th Hospital of People's Liberation Army, Quanzhou, China, from 1 June to 1 November 2019. PATIENTS: A total of 280 patients aged ≥18 years with American Society of Anesthesiologists' physical status 1 to 3 undergoing flexible bronchoscopy were studied. INTERVENTIONS: Patients were assigned randomly into one of two groups, a nasal cannula oxygenation (NCO) group (n = 140) using a nasal cannula to deliver oxygen (4 l min-1) or the SJOV group (n = 140) using a WNJ connected to a manual jet ventilator to provide SJOV at a driving pressure of 103 kPa, respiratory rate 20 min-1, FiO2 1.0 and inspiratory:expiratory (I:E) ratio 1:2. MAIN OUTCOME MEASURES: The primary outcome was an incidence of desaturation (defined as SpO2 < 90%) during the procedure. Other adverse events related to the sedation or SJOV were also recorded. RESULTS: Compared with the NCO group, the incidence of desaturation in the SJOV group was lower (NCO 37.0% vs. SJOV 13.1%) (P < 0.001). Patients in the SJOV group had a higher incidence of a dry mouth at 1 min (13.1% vs. 1.5%, P < 0.001) than at 30 min (1.5% vs. 0%, P = 0.159) or at 24 h (0% vs. 0%). There was no significant difference between the groups in respect of sore throat, subcutaneous emphysema or nasal bleeding. CONCLUSIONS: SJOV via a WNJ during flexible bronchoscopy under moderate to deep sedation with propofol and remifentanil significantly reduces the incidence of desaturation when compared with regular oxygen supplementation via a nasal cannula. Patients in the SJOV group had an increased incidence of transient dry mouth. TRIAL REGISTRATION: Registered at www.chictr.org.cn (ChiCTR1900023514).


Asunto(s)
Sedación Profunda , Propofol , Adolescente , Adulto , Broncoscopía , China , Humanos , Propofol/efectos adversos , Remifentanilo
14.
FASEB J ; 34(2): 1983-1995, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31907985

RESUMEN

Covariant residues identified by computational algorithms have provided new insights into enzyme evolutionary routes. However, the reliability and accuracy of routine statistical coupling analysis (SCA) are unable to satisfy the needs of protein engineering because SCA depends only on sequence information. Here, we set up a new SCA algorithm, SCA.SIM, by integrating structure information and MD simulation data. The more reliable covariant residues with high-quality scores are obtained from sequence alignment weighted by residual movement for eight related subfamilies, belonging to α/ß hydrolase family, with Candida antarctica lipase B (CALB). The 38 predicted covariant residues are tested for function by high-throughput quantitative evaluation in combination with activity and thermostability assays of a mutant library and deep sequencing. Based on the landscapes of both activity and thermostability, most mutants play key roles in catalysis, and some mutants gain 2.4- to 6-fold increase in half-life at 50°C and 9- to 12-fold improvement in catalytic efficiency. The activity of double mutants for A225F/T103A is higher than those of A225F and T103A which means that SCA.SIM method might be useful for identifying the allosteric coupling. The SCA.SIM algorithm can be used for protein coevolution and enzyme engineering research.


Asunto(s)
Algoritmos , Candida albicans/enzimología , Proteínas Fúngicas/química , Lipasa/química , Simulación de Dinámica Molecular , Pliegue de Proteína , Candida albicans/genética , Catálisis , Estabilidad de Enzimas , Proteínas Fúngicas/genética , Calor , Lipasa/genética , Dominios Proteicos
16.
Ann Clin Microbiol Antimicrob ; 16(1): 32, 2017 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-28420384

RESUMEN

BACKGROUND: Colistin has been considered as a last-line treatment option in severe infections caused by multidrug-resistant (MDR) gram-negative pathogens. However, the emergence of the mobile colistin resistance gene (mcr-1) has challenged this viewpoint. The aim of this study is to explore the prevalence of mcr-1 in Escherichia coli (E. coli) in a Chinese teaching hospital, and investigate their molecular characteristics. METHODS: A total of 700 E. coli isolates were used to screen mcr-1 by PCR and sequencing in a Chinese university hospital from August 2014 to August 2015. Susceptibility test of mcr-1-producing isolates was determined by Vitek -2 Compact system. 26 virulence factors (VFs), phylogenetic groups, Multi-locus sequence typing (MLST), and DNA Fingerprinting (ERIC-PCR) of strains were investigated by PCR. RESULTS: Four (0.6%) mcr-1 producing E. coli isolates were found in this study. The results of antibiotic susceptibility test showed that all four isolates were resistant to colistin, ciprofloxacin, levofloxacin, cefazolin, and trimethoprim/sulfamethoxazole, and were susceptible to amikacin, ertapenem and imipenem. In addition, all 4 isolates exhibited high-level resistance to aztreonam, cefotaxime and gentamicin. The numbers of VFs contained in mcr-1 positive isolates were no more than 4 in our study. MLST result demonstrated that these isolates were assigned to two sequence types: ST156 and ST167. The result of phylogenetic analysis showed that four mcr-1-positive isolates belong to two phylogenetic groups: A and B1 group. ERIC-PCR showed that four mcr-1 positive strains were categorized into three different genotypes. CONCLUSIONS: Our study demonstrated a low prevalence of mcr-1 in E. coli clinical isolates in a Chinese teaching hospital, and we have gained insights into the molecular characteristics of these mcr-1-positive strains. Increasing the surveillance of these infections, as well as taking effective infection control measures are urgently needed to take to control the transmission of mcr-1 gene.


Asunto(s)
Farmacorresistencia Bacteriana , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/análisis , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Adulto , Anciano de 80 o más Años , Antibacterianos/farmacología , China/epidemiología , Escherichia coli/clasificación , Infecciones por Escherichia coli/epidemiología , Proteínas de Escherichia coli/genética , Femenino , Hospitales Universitarios , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Tipificación Molecular , Filogenia , Reacción en Cadena de la Polimerasa , Prevalencia , Análisis de Secuencia de ADN
17.
Appl Microbiol Biotechnol ; 101(8): 3201-3211, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28074221

RESUMEN

As a crucial factor for biocatalysts, protein thermostability often arises from a combination of factors that are often difficult to rationalize. In this work, the thermostable nature of halohydrin dehalogenase from Agrobacterium radiobacter AD1 (HheC) was systematically explored using a combinatorial directed evolution approach. For this, a mutagenesis library of HheC mutants was first constructed using error-prone PCR with low mutagenesis frequency. After screening approximately 2000 colonies, six mutants with eight mutation sites were obtained. Those mutation sites were subsequently combined by adopting several rounds of iterative saturation mutagenesis (ISM) approach. After four rounds of saturation mutagenesis, one best mutant ISM-4 with a 3400-fold improvement in half-life (t 1/2) inactivation at 65 °C, 18 °C increase in apparent T m value, and 20 °C increase in optimum temperature was obtained, compared to wild-type HheC. To the best of our knowledge, the mutant represents the most thermostable HheC variant reported up to now. Moreover, the mutant was as active as wild-type enzyme for the substrate 1,3-dichloro-2-propanol, and they remained most enantioselectivity of wild-type enzyme in the kinetic resolution of rac-2-chloro-1-phenolethanol, exhibiting a great potential for industrial applications. Our structural investigation highlights that surface loop regions are hot spots for modulating the thermostability of HheC, the residues located at these regions contribute to the thermostability of HheC in a cooperative way, and protein rigidity and oligomeric interface connections contribute to the thermostability of HheC. All of these essential factors could be used for further design of an even more thermostable HheC, which, in turn, could greatly facilitate the application of the enzyme as a biocatalyst.


Asunto(s)
Agrobacterium tumefaciens/genética , Evolución Molecular Dirigida/métodos , Hidrolasas/genética , Hidrolasas/metabolismo , Agrobacterium tumefaciens/enzimología , Biocatálisis , Estabilidad de Enzimas , Biblioteca de Genes , Hidrolasas/química , Cinética , Modelos Moleculares , Mutagénesis , Mutación , Reacción en Cadena de la Polimerasa , Temperatura , alfa-Clorhidrina/análogos & derivados , alfa-Clorhidrina/metabolismo
18.
J Anesth ; 31(1): 144-147, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27848018

RESUMEN

The emergency difficult airway with the 'cannot intubate and cannot ventilate' (CICV) situation contributes to a high percentage of anesthesia- and emergency medicine-related morbidity and mortality. A new technique of supraglottic jet oxygenation and ventilation (SJOV) via the nasal approach was successfully used in an emergency to save a patient with a CICV difficult airway from a catastrophic outcome.


Asunto(s)
Intubación Intratraqueal , Respiración Artificial/métodos , Adulto , Anestesia/métodos , Anestesiología , Femenino , Humanos , Respiración , Ventiladores Mecánicos
19.
PLoS One ; 6(7): e22570, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21799901

RESUMEN

BACKGROUND: Genome-wide gene expression profile using deep sequencing technologies can drive the discovery of cancer biomarkers and therapeutic targets. Such efforts are often limited to profiling the expression signature of either mRNA or microRNA (miRNA) in a single type of cancer. METHODOLOGY: Here we provided an integrated analysis of the genome-wide mRNA and miRNA expression profiles of three different genitourinary cancers: carcinomas of the bladder, kidney and testis. PRINCIPAL FINDINGS: Our results highlight the general or cancer-specific roles of several genes and miRNAs that may serve as candidate oncogenes or suppressors of tumor development. Further comparative analyses at the systems level revealed that significant aberrations of the cell adhesion process, p53 signaling, calcium signaling, the ECM-receptor and cell cycle pathways, the DNA repair and replication processes and the immune and inflammatory response processes were the common hallmarks of human cancers. Gene sets showing testicular cancer-specific deregulation patterns were mainly implicated in processes related to male reproductive function, and general disruptions of multiple metabolic pathways and processes related to cell migration were the characteristic molecular events for renal and bladder cancer, respectively. Furthermore, we also demonstrated that tumors with the same histological origins and genes with similar functions tended to group together in a clustering analysis. By assessing the correlation between the expression of each miRNA and its targets, we determined that deregulation of 'key' miRNAs may result in the global aberration of one or more pathways or processes as a whole. CONCLUSIONS: This systematic analysis deciphered the molecular phenotypes of three genitourinary cancers and investigated their variations at the miRNA level simultaneously. Our results provided a valuable source for future studies and highlighted some promising genes, miRNAs, pathways and processes that may be useful for diagnostic or therapeutic applications.


Asunto(s)
Biomarcadores de Tumor/genética , Perfilación de la Expresión Génica , MicroARNs/genética , Neoplasias Urogenitales/genética , Carcinoma de Células Transicionales/genética , Carcinoma de Células Transicionales/metabolismo , Carcinoma de Células Transicionales/patología , Genómica , Humanos , Masculino , Neoplasias de Células Germinales y Embrionarias/genética , Neoplasias de Células Germinales y Embrionarias/metabolismo , Neoplasias de Células Germinales y Embrionarias/patología , ARN Mensajero/genética , Neoplasias Testiculares/genética , Neoplasias Testiculares/metabolismo , Neoplasias Testiculares/patología , Neoplasias Urogenitales/metabolismo , Neoplasias Urogenitales/patología
20.
J Agric Food Chem ; 56(16): 7201-7, 2008 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-18642839

RESUMEN

Water characteristics and meat microstructure of NaHCO3-enhanced pork were compared with NaCl- and Na4O7P2-enhanced pork using low-field proton NMR relaxometry, advanced microscopy techniques, and traditional meat quality measurements. Porcine samples were enhanced at 4 degrees C for 48 h with sodium salts individually and in the following combinations: (i) 5% NaCl, (ii) 5% Na4O7P2, (iii) 3% NaHCO3, (iv) 5% NaCl and 5% Na4O7P2, (v) 5% NaCl and 3% NaHCO3, (vi) 5% Na4O7P2 and 3% NaHCO3, and (vii) 5% NaCl, 5% Na4O7P2, and 3% NaHCO3. Independently of the marinade used, the water-binding capacity was improved, cooking loss was reduced, and the yield was enhanced compared with nonmarinated pork samples. This was also reflected in the water mobility within the samples measured by proton NMR relaxometry. Visualization of samples by confocal laser scanning microscopy (CLSM) revealed salt-dependent microstructural changes in the green pork samples treated with NaHCO3, giving rise to nearly complete disintegration of overall structures. High-resolution visualization by atomic force microscopy (AFM) further suggested that a higher cooking loss in sodium chloride-enhanced samples could be ascribed to less solubilization and higher heat-induced protein denaturation compared with phosphate- and bicarbonate-enhanced samples.


Asunto(s)
Manipulación de Alimentos/métodos , Carne/análisis , Agua/análisis , Animales , Bicarbonatos , Carbonatos , Calor , Espectroscopía de Resonancia Magnética , Microscopía de Fuerza Atómica , Cloruro de Sodio , Soluciones , Porcinos
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