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1.
Redox Biol ; 69: 103017, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38176315

RESUMEN

Flavonoids are bioactive natural polyphenolic compounds with health benefits, including anti-tumor, anti-inflammatory and anti-aging effects. Our previous studies revealed that a flavonoid 4,4'-dimethoxychalcone (DMC) induced ferroptosis via inhibiting ferrochelatase (FECH). However, the effect of DMC on cellular senescence is unknown. In the present study, we found that DMC treatment selectively eliminated senescent cells, and DMC alone or a combination of DMC and quercetin or dasatinib showed high efficiency in the clearance of senescent cells. We identified FECH was highly expressed in senescent cells compared to non-senescent cells. Mechanistically, we found that DMC inhibited FECH and induced ferritinophagy, which led to an increase of labile iron pool, triggering ferroptosis of senescent cells. Importantly, we found that DMC treatment prevented hair loss, improved motor coordination, and reduced the expression of several senescence-associated secretory phenotype factors (IL-6, IL-1ß, CXCL-10, and MMP12) in the liver of old mice. Collectively, we revealed that, through the induction of ferroptosis, DMC holds the promise as a new senolytics to prevent age-related pathologies.


Asunto(s)
Envejecimiento , Flavonoides , Ratones , Animales , Flavonoides/farmacología , Envejecimiento/metabolismo , Senescencia Celular , Quercetina , Dasatinib/farmacología
2.
World J Clin Cases ; 11(33): 8084-8088, 2023 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-38075569

RESUMEN

BACKGROUND: Granuloma annulare (GA) has diverse clinical manifestations including papules, plaques, and nodules on the extremities that are skin-colored, pink, or purple. Approximately 15% of all GA cases are considered generalized GA. CASE SUMMARY: Herein, we describe the case of a pediatric patient who initially presented with papules and later developed generalized atrophic macules. Upon examination, two different morphologic lesions were histopathologically confirmed: Epithelioid nodular GA and scattered histiocytic infiltrative GA. This patient exhibited rare clinical manifestations that differed throughout the course of the disease. The varying histopathological types and clinical manifestations of GA may be linked to the different stages of the disease. CONCLUSION: This rare case demonstrates the different histopathological features of different stages and clinical manifestations of granuloma annulare in an infant.

3.
Artículo en Inglés | MEDLINE | ID: mdl-37794691

RESUMEN

Although hypertension and obesity are both risk factors for left ventricular hypertrophy (LVH), the extent of their impact on LVH in the general population is still unclear, and the predictive value of obesity indicators for LVH remains to be elucidated. In this study, obesity-related indicators, including waist circumference (WC), waist-height ratio (WHTR), and waist-hip ratio (WHR), were used to define abdominal obesity (AO), whereas body mass index (BMI) was used to measure general obesity (GO). The effects of hypertension and obesity on LVH were estimated using logistic regression analysis, as was the relative risk of LVH based on the presence of obesity, hypertension, or both. Subgroup analyses were performed based on sex and age. Of the 9134 participants (≥35 years old), 915 (10.0%) developed LVH. After adjusting for covariates, the odds ratios (95% confidence intervals) for LVH were 3.94 (3.27-4.75) in patients with hypertension, 1.90 (1.60-2.26) in those with GO, and 1.45 (1.25-1.69), 1.69 (1.43-2.00), and 1.54 (1.33-4.75) in individuals with AO defined based on WC, WHTR, and WHR, respectively. Analysis by sex showed similar values in women, but AO based on WC and WHR were not significantly associated with LVH in men. Further, after adjusting for potential confounding factors, concomitant hypertension and obesity had an increased risk of developing LVH in all age ranges, particularly in patients aged 35-45 years (risk increased 14.14-fold, 10.84-fold, 7.97-fold, and 9.95-fold for BMI-based GO and WC-, WHTR-, and WHR-based AO, respectively), and in both men and women but particularly in men (risk increased 7.71-fold, 4.67-fold, 5.83-fold, and 5.58-fold, respectively). In summary, all obesity indicators (BMI, WC, WHTR, and WHR) had predictive value for LVH in women; however, only BMI and WHTR should be considered for men. Furthermore, monitoring for the occurrence and progression of LVH is imperative for rural Chinese patients with concomitant hypertension and obesity, especially men and those aged 35-45 years.

4.
World J Clin Cases ; 11(17): 4019-4025, 2023 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-37388784

RESUMEN

BACKGROUND: Granuloma annulare (GA) has diverse clinical manifestations, multiple subtypes, and unknown etiology and pathogenesis. Existing studies regarding GA in children are scarce. AIM: To examine the correlation between clinical manifestation and histopathology of pediatric GA. METHODS: A total of 39 patients under 18 years of age with both a clinical and pathological diagnosis of GA at Kunming Children's Hospital from 2017 to 2022 were retrieved. Their medical records were consulted, and clinical data of the children were recorded and summarized, including gender, age, disease site, etc. Existing wax blocks of skin lesion specimens of children and pathological films were retrieved for further study and relevant histology, including hematoxylin-eosin, Alcian blue, elastic fiber (Victoria blue-Lichon red method), and antacid staining. Finally, the children's clinical manifestations, histopathological results, and special staining characteristics were analyzed. RESULTS: The clinical manifestations of granuloma annulare in children were diverse: 11 cases presented with a single lesion, 25 with multiple lesions, and 3 with generalized lesions. The pathological typing comprised histiocytic infiltration, palisading granuloma, epithelioid nodular, and mixed types in 4, 11, 9, and 15 cases, respectively. Thirty-nine cases were negative for antacid staining. The positive rate of Alcian blue staining was 92.3%, and that of elastic fiber staining was 100%. The degree of elastic fiber dissolution and granuloma annulare histopathological typing were positively correlated (r = 0.432, P < 0.05). No correlation was found between clinical presentation and histopathological typing of the granuloma annulare in children. In the pathological diagnosis of granuloma annulare, the positive elastic fiber staining rate was higher than that of Alcian blue staining. A correlation was found between elastic fiber dissolution degree and histopathological staging. However, the differences in pathological staging may have been related to the pathological manifestation of granuloma annulare at different periods. CONCLUSION: Elastic fiber degradation may be a critical step in the pathogenesis of pediatric granuloma annulare. This is also one of the first studies focused on granuloma annulare in children.

5.
Am J Clin Oncol ; 46(7): 284-292, 2023 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-37145881

RESUMEN

BACKGROUND: Second primary malignancies (SPMs) after liver transplantation (LT) are becoming the leading causes of death in LT recipients. The purpose of this study was to explore prognostic factors for SPMs and to establish an overall survival nomogram. METHODS: A retrospective analysis was conducted of data from the Surveillance, Epidemiology, and End Results (SEER) database on adult patients with primary hepatocellular carcinoma who had undergone LT between 2004 and 2015. Cox regression analysis was used to explore the independent prognostic factors for SPMs. Nomogram was constructed using R software to predict the overall survival at 2, 3, and 5 years. The concordance index, calibration curves, and decision curve analysis were used to evaluate the clinical prediction model. RESULTS: Data from a total of 2078 patients were eligible, of whom 221 (10.64%) developed SPMs. A total of 221 patients were split into a training cohort (n=154) or a validation cohort (n=67) with a 7:3 ratio. The 3 most common SPMs were lung cancer, prostate cancer, and non-Hodgkin lymphoma. Age at initial diagnosis, marital status, year of diagnosis, T stage, and latency were the prognostic factors for SPMs. The C-index of the nomogram for overall survival in the training and validation cohorts were 0.713 and 0.729, respectively. CONCLUSIONS: We analyzed the clinical characteristics of SPMs and developed a precise prediction nomogram, with a good predictive performance. The nomogram we developed may help clinicians provide personalized decisions and clinical treatment for LT recipients.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Trasplante de Hígado , Neoplasias Primarias Secundarias , Adulto , Masculino , Humanos , Carcinoma Hepatocelular/cirugía , Neoplasias Hepáticas/cirugía , Modelos Estadísticos , Pronóstico , Estudios Retrospectivos , Análisis de Supervivencia , Programa de VERF
6.
CNS Neurosci Ther ; 29(10): 2826-2842, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37072933

RESUMEN

BACKGROUND: Activation of the NLRP3 inflammasome promotes microglia to secrete inflammatory cytokines and induce pyroptosis, leading to impaired phagocytic and clearance functions of microglia in Alzheimer's disease (AD). This study found that the autophagy-associated protein p62 interacts with NLRP3, which is the rate-limiting protein of the NLRP3 inflammasome. Thus, we aimed to prove that the degradation of NLRP3 occurs through the autophagy-lysosome pathway (ALP) and also demonstrate its effects on the function of microglia and pathological changes in AD. METHODS: The 5XFAD/NLRP3-KO mouse model was established to study the effect of NLRP3 reduction on AD. Behavioral experiments were conducted to assess the cognitive function of the mice. In addition, immunohistochemistry was used to evaluate the deposition of Aß plaques and morphological changes in microglia. BV2 cells treated with lipopolysaccharide (LPS) followed by Aß1-42 oligomers were used as in vitro AD inflammation models and transfected with lentivirus to regulate the expression of the target protein. The pro-inflammatory status and function of BV2 cells were detected by flow cytometry and immunofluorescence (IF). Co-immunoprecipitation, mass spectrometry, IF, Western blot (WB), quantitative real-time PCR, and RNA-seq analysis were used to elucidate the mechanisms of molecular regulation. RESULTS: Cognitive function was improved in the 5XFAD/NLRP3-KO mouse model by reducing the pro-inflammatory response of microglia and maintaining the phagocytic and clearance function of microglia to the deposited Aß plaque. The pro-inflammatory function and pyroptosis of microglia were regulated by NLRP3 expression. Ubiquitinated NLRP3 can be recognized by p62 and degraded by ALP, slowing down the proinflammatory function and pyroptosis of microglia. The expression of autophagy pathway-related proteins such as LC3B/A, p62 was increased in the AD model in vitro. CONCLUSIONS: P62 recognizes and binds to ubiquitin-modified NLRP3. It plays a vital role in regulating the inflammatory response by participating in ALP-associated NLRP3 protein degradation, which improves cognitive function in AD by reducing the pro-inflammatory status and pyroptosis of microglia, thus maintaining its phagocytic function.


Asunto(s)
Enfermedad de Alzheimer , Animales , Ratones , Enfermedad de Alzheimer/metabolismo , Autofagia , Cognición , Inflamasomas/metabolismo , Microglía , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo
7.
Mol Cell Probes ; 67: 101897, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36740149

RESUMEN

BACKGROUND: Pancreatic adenocarcinoma (PAAD) is a malignant tumor with a high mortality rate. Methylation modifications acted a crucial role to affect cancer progression. The current study aimed to explore the potential role of methylase regulators in PAAD prognosis and immune microenvironment. METHODS: PubMed and TCGA databases were used to systematically analyze methylase regulators in PAAD. We identified three methylase clusters based on RNA methylase transcriptome data and obtained three gene clusters based on methylase modification-related differently expressed genes using principal component analysis (PCA) analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Gene Ontology (GO) biological processes were performed to explore the processes enriched in the different subgroups and single sample gene-set enrichment analysis (ssGSEA) was used to analyze the relationship between subgroups and immune infiltration in PAAD. RESULTS: We systematically screened 43 methylase regulators in PAAD samples and identified three methylase clusters with different clinical outcomes, as well as detected a significant relationship between methylase clusters and tumor immune infiltration. The top ten mutated genes include TP53, Kirsten rat sarcoma viral oncogene homolog (KRAS), titin gene (TTN), mucin 16 (MUC16), SMAD4, cyclin-dependent kinase inhibitor 2a (CDKN2A), Ryanodine receptor isoform-1 (RYR1), ring finger 43 (RNF43), protocadherin-15 (PCDH15), and AT-rich interacting domain-containing protein 1 A gene (ARID1A). CONCLUSION: The current study constructed an m6A/m5C/m1A/m7G modulator genes and explored methylase modification-related genes, which were related to the prognosis of PAAD patients and the immune checkpoint point cytotoxic T-lymphocyte associated protein 4 (CTLA4). These findings may provide prognostic predictors and direction for immunotherapy strategies for the treatment of PAAD.


Asunto(s)
Adenocarcinoma , Neoplasias Pancreáticas , Humanos , Familia de Multigenes , Metiltransferasas , Regulación Neoplásica de la Expresión Génica , Microambiente Tumoral , Neoplasias Pancreáticas
8.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 44(3): 357-365, 2022 Jun.
Artículo en Chino | MEDLINE | ID: mdl-35791930

RESUMEN

Objective To explore the effects of interleukin-6 (IL-6) gene knockout on the cognitive function and pathological changes in 5×FAD transgenic mice of Alzheimer's disease.Methods IL-6+/- mice were crossed with 5×FAD mice to establish the 5×FAD;IL-6-/- mouse model,and 3-month-old and 10-month-old mice were selected for experiments.The cognitive function of mice was detected by behavioral tests,and HE staining and ß-amyloid (Aß) immunohistochemical staining were performed to detect the pathological changes of mouse brain tissue.Results The number of 5×FAD;IL-6-/- model mice (3 months old,n=20;10 months old,n=5) and 5×FAD littermate control (3 months old,n=26;10 months old,n=24) conformed to the Mendel's law.Compared with that of the 5×FAD mice at the same age,the discrimination ratio of 3-month-old 5×FAD;IL-6-/- mice increased in the novel object recognition test (q=3.890,P=0.002).Morris water maze test results showed that the 3-month-old 5×FAD;IL-6-/- mice had longer time spent in target quadrant (q=3.797,P=0.012) and more times of crossing platform (q=2.505,P=0.017) than the 5×FAD mice at the same age.The results of immunohistochemical staining showed that IL-6 knockout reduced the Aß deposition in the hippocampus (q=13.490,P=0.002;q=45.680,P<0.001) and cortex (q=16.830,P=0.001;q=14.180,P=0.001) of 5×FAD mice.Conclusion IL-6 gene knockout can significantly improve the spatial memory and reduce the Aß deposition in the brain of 5×FAD mice.


Asunto(s)
Enfermedad de Alzheimer , Enfermedad de Alzheimer/genética , Animales , Cognición , Modelos Animales de Enfermedad , Flavina-Adenina Dinucleótido , Técnicas de Inactivación de Genes , Interleucina-6 , Ratones , Ratones Noqueados
9.
Animal Model Exp Med ; 5(3): 227-238, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35746831

RESUMEN

BACKGROUND: Hypertension and dyslipidemia are considered reversible risk factors for cardiovascular disease. The purpose of this study was to explore the impact of traditional and nontraditional blood lipid profiles on the risk of left ventricular hypertrophy (LVH) and to explore the superposition effect of dyslipidemia combined with hypertension. METHODS: Data on 9134 participants (53.5 ± 10.3 years old) from the Northeast China Rural Cardiovascular Health Study (NCRCHS) were statistically analyzed. The blood lipid profile was measured by total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total glyceride (TG), and calculated nontraditional blood lipid indices including non-HDL-C, atherosclerosis index (AI), TC/HDL-C, and residual cholesterol (RC). RESULTS: After the adjustment of age and gender, the odds ratios (ORs) of LVH in patients with hypertension, high LDL-C, high non-HDL-C, high AI, and high TC/HDL-C were 3.97 (3.31-4.76), 1.27 (1.02-1.59), 1.21 (1.04-1.39), 1.33 (1.15-1.53), and 1.42 (1.22-1.65), respectively. After full adjustment of potential confounding factors, high AI and TC/HDL-C were associated with LVH rather than traditional blood lipid indices. The combination of hypertension and nontraditional dyslipidemia (defined by high AI and TC/HDL-C) was associated with the highest risk of LVH, especially in participants under 45 years of age. The risk was more significant in men, 5.09-fold and 6.24-fold, respectively, compared with 3.66-fold and 4.01-fold in women. CONCLUSIONS: People with dyslipidemia defined by nontraditional blood lipid indices (high AI and high TC/HDL-C) and hypertension were more likely to develop LVH.


Asunto(s)
Aterosclerosis , Dislipidemias , Hipertensión , Adulto , Colesterol , HDL-Colesterol , LDL-Colesterol , Dislipidemias/complicaciones , Femenino , Humanos , Hipertensión/complicaciones , Hipertrofia Ventricular Izquierda/etiología , Lípidos , Masculino , Persona de Mediana Edad
10.
J Fungi (Basel) ; 8(3)2022 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-35330223

RESUMEN

Corn mashes have high-viscosity and high-sugar characteristics, which hinders yeast-fermentation efficiency and the ethanol yield increase. The excessive viscosity of corn mash is caused by the unutilized cellulose in corn kernel fiber. A novel lignocellulolytic enzymes cocktail with strong substrate specificity was prepared for high-viscosity, high-sugar corn mash. The in situ conversion of corn mashes with novel lignocellulolytic enzymes at the optimum cellulase dosage of 50 FPU/L resulted in about 12% increased ethanol concentration compared with the reference mash at different batch-fermentation scales. Adding the lignocellulolytic enzymes caused the greatest decrease in viscosity of corn mash and residual sugars by 40.9% and 56.3%, respectively. Simultaneously, the application of lignocellulolytic enzymes increased the value of the dried distiller's grain with solubles (DDGS) by increasing the protein content by 5.51%. The in situ conversion of cellulose can decrease the fermentation broth viscosity and improve the rheological property, thereby improving the ethanol yield. With the same amount of material, the application of the novel enzymes cocktail can enhance the ethanol yield by more than 12%. A quarter of the ethanol yield increase was due to the further hydrolysis of starch, while three quarters to cellulose. Thus, this technology will increase the net revenue of bioethanol industrialization.

11.
Cell Cycle ; 21(3): 261-275, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34951563

RESUMEN

Circular RNA hsa_circ_0088364 (circ_0088364) is a contributory factor in the malignancy of hepatocellular carcinoma (HCC). We aimed to elaborate its role and competing endogenous RNA (ceRNA) mechanism in HCC cell growth and motility. Expression of circ_0088364, microRNA (miR)-1270 and Collagen type IV alpha 1 chain (COL4A1) was measured by real-time quantitative PCR and Western blotting, and their relationships were determined by dual-luciferase reporter assay, RNA immunoprecipitation, biotinylated RNA pull-down, and Spearman's rank correlation analysis. Cellular programs were measured by cell counting kit-8 assay, flow cytometry and transwell assays, Western blotting, and xenograft experiment. Expression of circ_0088364 and COL4A1 was upregulated, and miR-1270 was downregulated in HCC patients' tumors; moreover, there were linear correlations among circ_0088364, miR-1270, and COL4A1 expression. Essentially, circ_0088364 and COL4A1 were ceRNAs for miR-1270 via target binding. In function, silencing circ_0088364 or upregulating miR-1270 could suppress cell proliferation, cell cycle entrance, transwell migration and invasion in Huh7 and HCCLM3 cells, as well as promote apoptosis rate. Moreover, above-mentioned effects were accompanied with reduced B-cell lymphoma (Bcl)-2, N-cadherin and Vimentin levels, and elevated Bcl-2-associated X protein (Bax) and E-cadherin levels. Contrarily, exhausting miR-1270 and restoring COL4A1 could severally abrogate the tumor-suppressive roles of circ_0088364 knockdown and miR-1270 overexpression in HCC cells in vitro. In vivo, silencing circ_0088364 retarded xenograft tumor growth in nude mice induced by Huh7 cells by upregulating miR-1270 and downregulating COL4A1. Blocking circ_0088364 suppressed HCC by inhibiting cell growth and motility via targeting miR-1270-COL4A1 axis.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroARNs , ARN Circular/genética , Animales , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Proliferación Celular/genética , Colágeno Tipo IV , Humanos , Neoplasias Hepáticas/patología , Ratones , Ratones Desnudos , MicroARNs/genética , MicroARNs/metabolismo
12.
Bioresour Technol ; 329: 124925, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33676352

RESUMEN

In this study, an integrated device with scrubbing and biochemical treatment functions was used, and partial nitrification (PN)-Anammox and sulfur autotrophic denitrification (SADN) processes were coupled in a biochemical treatment pond to explore the feasibility of in-situ autotrophic removal of NH3 and H2S. The results showed that the removal efficiency of NH3 and H2S in waste gas are 95% and 87.5% respectively. The scrubbing liquid was efficiently treated in the biochemical treatment pond. Nitrogenous compounds weren't accumulated in liquid and converted to N2 by SADN and PN-Anammox coupling system. S2- was mainly used by SADN process to reduce NO3-. The scrubbing liquid processed by the biochemical treatment pond was refluxed to the scrubber to achieve continuous absorption of NH3 and H2S. Microbial community and functional microbial analysis showed that the PN-Anammox and SADN processes were the main processes to achieve the conversion of pollutants in the scrubbing liquid.


Asunto(s)
Desnitrificación , Nitrificación , Procesos Autotróficos , Reactores Biológicos , Nitrógeno/análisis , Oxidación-Reducción , Azufre , Aguas Residuales
14.
ACS Omega ; 5(21): 11987-11997, 2020 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-32548377

RESUMEN

Different metal ions were used to modify Hß zeolite adsorbents by an impregnation method to remove organic chlorides from the model naphtha. The dechlorination performance of different ion-modified adsorbents was evaluated using a microcoulometer. The effects of calcination time and temperature, metal loading, adsorption time and temperature, and dosage of adsorbent were investigated by batch adsorption experiments. The modified adsorbents were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), NH3-temperature-programmed desorption (TPD), scanning electron microscopy (SEM), infrared spectroscopy of pyridine adsorption (Py-IR), and X-ray photoelectron spectroscopy (XPS). After modification, the modified Zn/Hß zeolite exhibited the best dechlorination performance among the other metal-loaded zeolites. The removal percentage of organic chloride of the Zn/Hß adsorbent prepared at optimum preparation and adsorption conditions can reach 72.54%, compared with 34.07% of Hß zeolite. The Zn/Hß adsorbent also maintained good dechlorination performance after regeneration by calcination for five times. The characterization results revealed that the concentration of the B acid sites in the zeolite decreased with the introduction of the metals, whereas that of the L acid sites increased. Zn/Hß zeolite had the lowest B/L ratio but the best dechlorination performance, which meant that the type and amount of acidic sites present in zeolites played a significant role in dechlorination performance and L acid was beneficial for chloride compound removal.

15.
PLoS One ; 15(2): e0229232, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32049998

RESUMEN

[This corrects the article DOI: 10.1371/journal.pone.0099741.].

16.
J Am Chem Soc ; 141(36): 14451-14459, 2019 09 11.
Artículo en Inglés | MEDLINE | ID: mdl-31432675

RESUMEN

Searching for viable strategies to accelerate the catalytic cycle of glycoside hydrolase family 7 (GH7) cellobiohydrolase I (CBHI)-the workhorse cellulose-degrading enzymes, we have performed a total of 12-µs molecular dynamics simulations on GH7 CBHI, which brought to light a new mechanism for cellobiose expulsion, coined "claw-arm" action. The loop flanking the product binding site plays the role of a flexible "arm" extending toward cellobiose, and residue Thr389 of this loop acts as a "claw" that captures cellobiose. Five mutations of residue Thr389 were considered to enhance the loop-cellobiose interaction. The lysine mutant was found to significantly accelerate cellobiose expulsion and facilitate polysaccharide-chain translocation. Lysine mutation of Thr393 in Talaromyces emersonii CBHI (TeCel7A) performed similarly. Lysine approaches the catalytic area and stabilizes the Michaelis complex, potentially affecting glycosylation, the rate-limiting step of the catalytic cycle. QM/MM calculations indicate that lysine replacement diminishes the barrier against proton transfer, the crucial step of glycosylation, by 2.3 kcal/mol. Experimental validation was performed using the full-length wild-type (WT) of TeCel7A and its mutants, recombinantly expressed in Pichia pastoris, to degrade the substrates. Compared with the WT, the lysine mutant revealed an associated higher enzymatic reaction rate. Furthermore, cellobiose yield was also increased by lysine mutation, indicating that dissociation of the enzyme from cellulose was accelerated, which largely stems from the enhanced flexibility of the "arm". The present work is envisioned to help design strategies for improving enzymatic activity, while decreasing enzyme cost.


Asunto(s)
Celulosa 1,4-beta-Celobiosidasa/metabolismo , Lisina/metabolismo , Biocatálisis , Celulosa 1,4-beta-Celobiosidasa/química , Lisina/química , Lisina/genética , Simulación de Dinámica Molecular , Mutación , Talaromyces/enzimología
17.
J Ind Microbiol Biotechnol ; 46(11): 1603-1610, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31375945

RESUMEN

The selection of improved producers among the huge number of variants in mutant libraries is a key issue in filamentous fungi of industrial biotechnology. Here, we developed a droplet-based microfluidic high-throughput screening platform for selection of high-cellulase producers from filamentous fungus Trichoderma reesei. The screening system used a fluorogenic assay to measure amount of cellulase and its activity. The key effectors such as cellulase-inducing medium, spore germination, droplet cultivation time, droplet fluorescence signal detection, and droplet cell sorting were studied. An artificial pre-mixed library of high- and low-cellulase-producing T. reesei strains was screened successfully to verify the feasibility of our method. Finally, two cellulase hyperproducers exhibiting improvements in cellulase activity of 27% and 46% were isolated from an atmospheric and room-temperature plasma (ARTP)-mutated library. This high-throughput screening system could be applied to the engineering of T. reesei strains and other industrially valuable protein-producing filamentous fungi.


Asunto(s)
Celulasa/metabolismo , Microfluídica , Trichoderma/metabolismo , Biblioteca de Genes , Trichoderma/genética
18.
Food Chem ; 274: 444-451, 2019 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-30372963

RESUMEN

The effects of different processing methods were investigated, including on the fluidity, solubility, nutrient composition, digestibility, color and aroma constituent of instant brown rice powder. It showed that, except for flavonoids, different processing methods significantly influenced the indexes of the instant brown rice flour (p < 0.05). Germination could deteriorate the fluidity and solubility of brown rice powder and reduce the digestibility of protein, and starch. Exogenous enzyme treatment improved the fluidity and solubility of the brown rice powder as well as the digestion rate of protein and starch. The synergistic treatment of germination and exogenous enzymes significantly increased the digestibility of starch, but it deteriorated the fluidity, the rate of agglomeration and dispersion time. Comparing with DGBRE, DBRE produced a better quality instant brown rice powder.


Asunto(s)
Culinaria/métodos , Valor Nutritivo , Oryza/química , Oryza/metabolismo , Color , Digestión , Proteínas de Plantas/análisis , Polvos , Solubilidad , Almidón/análisis
19.
J Biosci Bioeng ; 127(4): 486-491, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30366719

RESUMEN

An inducer is crucial for cellulase production. In this study, duckweed was used as an inducer of cellulase production by Trichoderma reesei RUT C30. In a reaction induced by 50 g/L duckweed in shake flasks, the filter-paper activity (FPA) reached 6.5 FPU/mL, a value comparable to that induced by avicel. The enzyme-hydrolysis rate induced by steam-exploded corn stalk was 54.2%, representing a 28% improvement over that induced by avicel. The duckweed starch was hydrolyzed to glucose, which was subsequently used for biomass accumulation during the fermentation process. Furthermore, to optimize the control of the fermentation process, a combined substrate of avicel and duckweed was used to induce cellulase production by T. reesei RUT C30. The cellulase production and hydrolysis rates of the combined substrate, compared with avicel alone, were 39.6% and 36.7% higher, respectively. The results of this study suggest that duckweed is a good inducer of cellulase production in T. reesei, and it might aid in decreasing the cost of lignocellulosic materials hydrolysis.


Asunto(s)
Alismatales/fisiología , Celulasa/biosíntesis , Trichoderma , Alismatales/química , Técnicas de Cultivo Celular por Lotes , Biomasa , Celulosa/farmacología , Inducción Enzimática/efectos de los fármacos , Fermentación , Regulación Fúngica de la Expresión Génica/efectos de los fármacos , Hidrólisis/efectos de los fármacos , Extractos Vegetales/farmacología , Vapor , Trichoderma/efectos de los fármacos , Trichoderma/enzimología , Trichoderma/genética , Trichoderma/metabolismo , Zea mays/química
20.
Biochem Biophys Res Commun ; 505(3): 816-822, 2018 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-30297112

RESUMEN

The lack of efficient tumor invasion and metastatic biomarkers led to high mortality rates in colon cancer patients. Aberrant expression of ubiquitin-specific protease 6 (USP6) was involved in several diseases including cancer, while its role in the progression of colon cancer was still unclear. In this study, USP6 was evaluated at both mRNA and protein levels by using RT-PCR, western blot and immunohistochemistry staining analyses. The results revealed that high USP6 expression predicted poor disease-specific survival and overall survival through Kaplan-Meier analyses with log-rank tests, univariate and multivariate Cox analyses. Furthermore, cell function assay demonstrated that USP6 could promote colon cancer cells' invasion in vitro and liver metastasis in vivo. These findings indicated that high USP6 expression contributed to the progression of colon cancer and USP6 may be a valuable prognostic factor in patients with colon cancer.


Asunto(s)
Neoplasias del Colon/patología , Invasividad Neoplásica , Metástasis de la Neoplasia , Proteínas Proto-Oncogénicas/fisiología , Ubiquitina Tiolesterasa/fisiología , Anciano , Línea Celular Tumoral , Neoplasias del Colon/diagnóstico , Neoplasias del Colon/mortalidad , Progresión de la Enfermedad , Femenino , Humanos , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Pronóstico , Proteínas Proto-Oncogénicas/análisis , Proteínas Proto-Oncogénicas/genética , ARN Mensajero/análisis , Análisis de Supervivencia , Ubiquitina Tiolesterasa/análisis , Ubiquitina Tiolesterasa/genética
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