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1.
Cell Death Dis ; 11(3): 159, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32123165

RESUMO

Hereditary distal renal tubular acidosis (dRTA) is a rare disease of H+ excretion defect of α-intercalated cells in renal collecting duct, caused by decreased V-ATPase function due to mutations in the ATP6V1B1 or ATP6V0A4 genes. In the present study, a genetic family with 5 members of the complete dRTA phenotype were found with distal tubule H+ secretion disorder, hypokalemia, osteoporosis, and kidney stones. A variant NM_020632.2:c.1631C > T (p.Ser544Leu) in exon 16 on an ATP6V0A4 gene associated with dRTA was detected by next generation sequencing target region capture technique and verified by Sanger sequencing, which suggested that except for one of the patients who did not receive the test, the other four patients all carried the p.S544L heterozygote. In transfected HEK293T cells, cells carrying p.S544L-mut showed early weaker ATPase activity and a slower Phi recovery rate after rapid acidification. By immunofluorescence localization, it was observed that the expression level of p.S544L-mut on the cell membrane increased and the distribution was uneven. Co-immunoprecipitation showed the a4 subunit of ATP6V0A4/p.S544L-mut could not bind to the B1 subunit, which might affect the correct assembly of V-ATPase. The present study of dRTA family suggests that the p.S544L variant may be inherited in a dominant manner.

2.
J Diabetes Res ; 2020: 8726268, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32149155

RESUMO

Background: Fulminant type l diabetes mellitus (FT1DM) is a subtype of type 1 diabetes mellitus (T1DM) with abrupt onset, but data on its progression was limited. This study was aimed at exploring the clinical features through one-year follow-up. Methods and Materials. Patients with T1DM finishing at least one-year follow-up from June 2011 to July 2018 were enrolled from Guangdong Type 1 Diabetes Translational Medicine Study. Patients who fulfilled the respective criteria were categorized as an FT1DM group and a typical T1DM group (TT1DM). The 1 : 4 propensity score matching based on onset age, duration, and gender was performed between the FT1DM and TT1DM groups. Characteristics at the onset and after one-year follow-up were compared between the two groups. Results: A total of 53 patients with FT1DM and 212 matched patients with TT1DM were included. At the onset, there was a shorter duration of symptomatic period before diagnosis observed in the FT1DM group than in the TT1DM group (2 [1, 7] vs. 30 [10, 60] days, P < 0.001). FT1DM patients had higher plasma glucose levels and higher percentage of diabetes ketoacidosis (P < 0.001). FT1DM patients had higher plasma glucose levels and higher percentage of diabetes ketoacidosis (P < 0.001). FT1DM patients had higher plasma glucose levels and higher percentage of diabetes ketoacidosis (P < 0.001). FT1DM patients had higher plasma glucose levels and higher percentage of diabetes ketoacidosis (P < 0.001). FT1DM patients had higher plasma glucose levels and higher percentage of diabetes ketoacidosis (P < 0.001). FT1DM patients had higher plasma glucose levels and higher percentage of diabetes ketoacidosis (P < 0.001). FT1DM patients had higher plasma glucose levels and higher percentage of diabetes ketoacidosis (P < 0.001). FT1DM patients had higher plasma glucose levels and higher percentage of diabetes ketoacidosis (. Conclusion: Patients with FT1DM had more severe metabolic derangement and deficiency of insulin secretion than patients with TT1DM at the onset, but glycaemic and metabolic control was not worse than that in TT1DM.

3.
Neurobiol Learn Mem ; 171: 107210, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32145408

RESUMO

Epigenetic mechanisms of learning and memory are particularly interesting topics in neuroscience that have recently been investigated. As shown in our previous study, IQGAP1, a scaffolding protein of MAPK, is involved in fear memory through interactions with GluN2A-containing NMDA receptors and the ERK1/2 cascade. However, researchers have not determined whether histone posttranslational modifications are regulated by the IQGAP1/ERK signaling pathway. We performed in vivo studies using IQGAP1-/- and IQGAP1+/+ mice to provide insights into the specific functions of IQGAP1 in memory processes and the precise mechanisms underlying its regulatory effects. IQGAP1-/- mice exhibited impaired fear memory, decreased levels of phosphorylated ERK1/2 and histone H3S10, decreased acetylation of H3K14, and decreased c-Fos expression in the hippocampus compared to IQGAP1+/+ mice after fear conditioning. HDAC2 was significantly enriched at the c-fos gene promoter in IQGAP1-/- mice. Correspondingly, the disruption of the epigenetic regulation induced by ERK1/2 signaling through an intra-hippocampal injection of the MEK antagonist U0126 or GluN2A-selective pharmacological antagonist NVP-AAM077 blocked context-dependent memory formation, while no changes were observed after treatment with the GluN2B-selective antagonist Ro25-6981. The administration of SAHA, a non-specific HDAC inhibitor, or knock-down of HDAC2 with shHDAC2-AAV in the dorsal hippocampus significantly rescued the impaired fear memory formation, H3S10 phosphorylation, H3K14 acetylation, and c-Fos expression in IQGAP1-/- mice. Thus, we postulated that the IQGAP1/ERK-dependent mechanism regulating histone posttranslational modifications via HDAC2 potentially underlies memory formation.

4.
Sci Adv ; 6(10): eaaz1094, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32181358

RESUMO

Mesenchymal stem cells (MSCs) encapsulation by three-dimensionally (3D) printed matrices were believed to provide a biomimetic microenvironment to drive differentiation into tissue-specific progeny, which made them a great therapeutic potential for regenerative medicine. Despite this potential, the underlying mechanisms of controlling cell fate in 3D microenvironments remained relatively unexplored. Here, we bioprinted a sweat gland (SG)-like matrix to direct the conversion of MSC into functional SGs and facilitated SGs recovery in mice. By extracellular matrix differential protein expression analysis, we identified that CTHRC1 was a critical biochemical regulator for SG specification. Our findings showed that Hmox1 could respond to the 3D structure activation and also be involved in MSC differentiation. Using inhibition and activation assay, CTHRC1 and Hmox1 synergistically boosted SG gene expression profile. Together, these findings indicated that biochemical and structural cues served as two critical impacts of 3D-printed matrix on MSC fate decision into the glandular lineage and functional SG recovery.

6.
Adv Mater ; : e1907499, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32080903

RESUMO

Polymer composites with electrically conductive fillers have been developed as mechanically flexible, easily processable electromagnetic interference (EMI) shielding materials. Although there are a few elastomeric composites with nanostructured silvers and carbon nanotubes showing moderate stretchability, their EMI shielding effectiveness (SE) deteriorates consistently with stretching. Here, a highly stretchable polymer composite embedded with a three-dimensional (3D) liquid-metal (LM) network exhibiting substantial increases of EMI SE when stretched is reported, which matches the EMI SE of metallic plates over an exceptionally broad frequency range of 2.65-40 GHz. The electrical conductivities achieved in the 3D LM composite are among the state-of-the-art in stretchable conductors under large mechanical deformations. With skin-like elastic compliance and toughness, the material provides a route to meet the demands for emerging soft and human-friendly electronics.

7.
J Diabetes ; 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32040241

RESUMO

BACKGROUND: Limited data on the efficacy of the additional metformin therapy in patients with type 1 diabetes mellitus (T1DM) under real-life conditions have been available so far. METHODS: Patients aged ≥18 years with a duration of T1DM for at least 1 year were included in this multicenter observational study. Patients with insulin combined with metformin therapy (MET group) were compared with those with insulin therapy only (INS group). RESULTS: A total of 76 patients in the MET group were compared with 655 patients in the INS group. At baseline, patients with dyslipidemia were more prevalent in the MET group (17.6% vs 9.0%; P = .006), and they also had a higher body mass index (BMI) (21.7 ± 3.2 kg/m2 vs 20.4 ± 2.6 kg/m2 ; P < .001) than those in the INS group. But glycosylated hemoglobin (HbA1c) and daily insulin dose were not significantly different between the two groups. After 1-year follow-up, HbA1c decreased in both groups, while the daily insulin dose decreased in the MET group, but did not change in the INS group (-0.02 IU/kg [-0.16, 0.09] vs 0 IU/kg [-0.09, 0.09]; P = .029). The additional metformin therapy led to no change of BMI and weight in the MET group, while the body weight increased from 53.7 ± 8.6 kg to 55.0 ± 7.9 kg in the INS group (P < .001). CONCLUSIONS: Metformin is initiated more in T1DM patients with dyslipidemia or higher BMI in current practice in China. The addition of metformin is effective in maintaining weight and reducing the insulin dosage without improving glycemic control in patients with T1DM. HIGHLIGHTS: This is the first study to explore the current status and efficacy of additional metformin therapy in patients with type 1 diabetes mellitus (T1DM) under real-life conditions in China. Metformin is initiated more in T1DM patients with dyslipidemia or higher body mass index in current practice in China. Additional metformin has no effect on glycemic control, but it helps maintain body weight and reduce insulin dosage in adult patients with T1DM.

8.
J Agric Food Chem ; 68(5): 1337-1346, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31933359

RESUMO

The strong and inducible cbh1 promoter is most widely used to express heterologous proteins, useful in food and feed industries, in Trichoderma reesei. Enhancing its ability to direct transcription provides a general strategy to improve protein production in T. reesei. The cbh1 promoter was engineered by replacing eight binding sites of the transcription repressor ACE1 to those of the activators ACE2, Hap2/3/5, and Xyr1. While changing ACE1 to Hap2/3/5-binding sites completely abolished the transcription ability, replacements with ACE2- and Xyr1-binding sites (designated cbh1pA and cbh1pX promoters, respectively) largely improved the promoter transcription efficiency, as reflected by expression of a reporter gene DsRed. The cbh1pA and cbh1pX promoters were applied to improve secretory expression of a codon-optimized mannanase from Aspergillus niger to 3.6- and 5.0-fold higher, respectively, which has high application potential in feed industry.


Assuntos
Proteínas Fúngicas/metabolismo , Regiões Promotoras Genéticas , Proteínas Repressoras/metabolismo , Transativadores/metabolismo , Trichoderma/genética , Sítios de Ligação , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Engenharia Genética , Ligação Proteica , Proteínas Repressoras/genética , Transativadores/genética , Trichoderma/metabolismo
9.
Adv Mater ; 32(8): e1906652, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31951066

RESUMO

The performance of pseudocapacitive electrodes at fast charging rates are typically limited by the slow kinetics of Faradaic reactions and sluggish ion diffusion in the bulk structure. This is particularly problematic for thick electrodes and electrodes highly loaded with active materials. Here, a surface-functionalized 3D-printed graphene aerogel (SF-3D GA) is presented that achieves not only a benchmark areal capacitance of 2195 mF cm-2 at a high current density of 100 mA cm-2 but also an ultrahigh intrinsic capacitance of 309.1 µF cm-2 even at a high mass loading of 12.8 mg cm-2 . Importantly, the kinetic analysis reveals that the capacitance of SF-3D GA electrode is primarily (93.3%) contributed from fast kinetic processes. This is because the 3D-printed electrode has an open structure that ensures excellent coverage of functional groups on carbon surface and facilitates the ion accessibility of these surface functional groups even at high current densities and large mass loading/electrode thickness. An asymmetric device assembled with SF-3D GA as anode and 3D-printed GA decorated with MnO2 as cathode achieves a remarkable energy density of 0.65 mWh cm-2 at an ultrahigh power density of 164.5 mW cm-2 , outperforming carbon-based supercapacitors operated at the same power density.

10.
Sci China Life Sci ; 63(1): 80-91, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31637575

RESUMO

An effect of inhibition of tumor necrosis factor-α (TNF-α) on differentiation of mesenchymal stromal cells (MSCs) has been demonstrated, but the exact mechanisms that govern MSCs differentiation remain to be further elucidated. Here, we show that TNF-α inhibits the differentiation of MSCs to sweat glands in a specific sweat gland-inducing environment, accompanied with reduced expression of Nanog, a core pluripotency factor. We elucidated that fat mass and obesity-associated protein (FTO)-mediated m6A demethylation is involved in the regulation of MSCs differentiation potential. Exposure of MSCs to TNF-α reduced expression of FTO, which demethylated Nanog mRNA. Reduced expression of FTO increased Nanog mRNA methylation, decreased Nanog mRNA and protein expression, and significantly inhibited MSCs capacity for differentiation to sweat gland cells. Our finding is the first to elucidate the functional importance of m6A modification in MSCs, providing new insights that the microenvironment can regulate the multipotency of MSCs at the post-transcriptional level. Moreover, to maintain differentiation capacity of MSCs by regulating m6A modification suggested a novel potential therapeutic target for stem cell-mediated regenerative medicine.

11.
Diabetes Metab Res Rev ; 36(2): e3228, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31655017

RESUMO

BACKGROUND: The aim of our study is to investigate whether preproinsulin (PPI) could trigger a proinflammatory CD4+ T cell response in Chinese patients with type 1 diabetes (T1D). METHODS: Peripheral blood mononuclear cells were stimulated by a pool of 13 PPI peptides. Additional five PPI peptides previously proved to be antigenic in other cohorts of patients with T1D were also used. PPI reactive T cell responses were measured by interferon (IFN)-γ ELISPOT assay. RESULTS: Fifty-one Chinese patients with T1D were enrolled in this study and 72.34% of them were positive for at least one islet autoantibody. The stimulation index (SI) value of IFN-γ response to PPI peptide pool or peptides with dominant epitopes was below 3 in patients when SI≥3 was used as the positive cut-off value. Two peptides (B9-23 and C19-A3) restricted to DQ8 or DR4 molecule failed to induce positive IFN-γ response in patients with high-risk HLA-DQ8 or HLA-DR4/DR9 alleles. RNA-seq analysis of PPI specific CD4+ T cell lines further showed that most of the IFN-γ associated genes remained unchanged. CONCLUSIONS: This is the first report of CD4+ T cell epitope mapping of PPI in Chinese T1D. The lack of positive IFN-γ response to PPI peptides indicates that PPI might not be the principal antigenic candidate for autoreactive CD4+ T cells in Chinese T1D. Therefore, the efficacy of PPI-based immunotherapies in attenuating proinflammatory CD4+ T cell response requires further investigation.

12.
J Agric Food Chem ; 68(8): 2570-2577, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-31760747

RESUMO

The mycotoxin zearalenone (ZEN) is a secondary metabolite produced mainly by Fusarium species. ZEN poses health hazards both for humans and animals, as a major contaminant in the food and feed industries. Currently, there is no effective technique for degrading ZEN during industrial processes. In this study, we isolated and biochemically characterized a novel lactone hydrolase, ZHD607, isolated from Phialophora americana, cloned, and exogenously expressed in Pichia pastoris. ZHD607 was characterized as a mesophilic lactone hydrolase having a neutral pH and showing optimal activity at 35 °C and pH 8.0. Two mutants, ZHDM1 and I160Y, generated from ZHD607 based on structure and sequence alignment analyses, exhibited 2.9- and 3.4-fold higher activity towards ZEN than did ZHD607. Molecular dynamics simulation revealed diverse mechanisms driving this improved catalytic activity. These findings enrich our knowledge about ZHD enzyme family and represent an important step toward industrialization of ZEN-detoxifying lactone hydrolases.

13.
14.
J Biosci Bioeng ; 129(1): 16-22, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31400994

RESUMO

The economical production of pectin oligosaccharides with a specific degree of polymerization and structure from agro-food waste is an industrially important process. This study identified a novel pectate lyase gene (plhy1) from the thermophilic cellulolytic fungus H. insolens Y1 and tested its ability to produce pectin oligosaccharides. The recombinant PLHY1 produced in Pichia pastoris was superior to other similar enzymes due to its high thermal and pH stability. PLHY1 demonstrated optimal enzymatic activity at 55°C and pH 10.0 in the presence of 0.4 mM Ca2+, and preferred methyl esterified substrates for digestion. High performance anion exchange chromatography-pulsed amperometric detector and ultra high performance liquid chromatography in combination with electrospray ionization tandem mass spectrometry analysis showed that galacturonic acid-oligosaccharides with a small degree of polymerization (4-6) were the major hydrolysates produced by the degradation of apple peel pectin by PLHY1. The properties of PLHY1 make it valuable for application in the agro-food industry for the production of pectin oligosaccharides.

15.
J Org Chem ; 85(4): 1915-1926, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-31823616

RESUMO

Hexafluoroisopropanol has been demonstrated as the versatile promoter for redox-neutral α-C(sp3)-H functionalization of cyclic amines via the cascade [1,5]-hydride transfer/cyclization strategy. A wide range of cyclic amines are functionalized into bioactive tetrahydroquinolines, quinazolines, benzoxazines, and benzotriazepines in moderate to excellent yields. This protocol features additive-free conditions, operational simplicity, and wide substrate scope.

16.
Food Chem ; 310: 125970, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31838375

RESUMO

Glucose oxidases are widely used in various industrial processes, including bread baking. In this study, a novel glucose oxidase gene, CngoxA, from Cladosporium neopsychrotolerans SL16, was cloned and expressed in Pichia pastoris. Recombinant CnGOXA exhibited maximal activity at 20 °C and pH 7.0, and was stable at 30 °C and pH 6.0-9.0 for 1 h, with a half-life of 15 min at 40 °C. Compared with CnGOXA, the half-life of its mutant CnGOXA-M1 (Y169C-A211C), at 40 °C increased approximately 48-fold, and was stable at 30 °C and pH 3.0-12.0 for 1 h. The kcat and catalytic efficiency of CnGOXA-M1 were enhanced 0.7- and 1.6-fold, respectively. Both enzymes were cold-adapted and highly resistant to SDS. Furthermore, CnGOXA-M1 had a more significant effect on bread volume than that of GOX from Aspergillus niger. These favorable enzymatic properties of CnGOXA-M1 make it a potentially useful enzyme for many industrial applications.

17.
Methods Mol Biol ; 2091: 155-162, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31773579

RESUMO

Phytases can catalyze the hydrolysis of indigestible phytate and releases the usable phosphorus. Protease resistance and high activity of enzymes facilitate their biotechnological and medical application. Here we described a genetic manipulation method to improve enzyme tolerance to pepsin, trypsin, and low pH by optimizing the residual side chain of trypsin- and pepsin-sensitive HAP phytase YeAPPA from Yersinia enterocolitica.

18.
Int J Med Inform ; 135: 104054, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31864129

RESUMO

BACKGROUND: Systems-centered root cause analysis (RCA) of patient safety events presents unique advantages as it aims to disclose vulnerabilities of healthcare systems. However, the increasing number of collected events poses the problems of low efficiency and information overload for traditional RCA. OBJECTIVES: This study aims to improve systems-centered RCA by developing optimized information extraction and presentation. METHODS: We experimented supervised machine-learning methods to extract safety-related information from 3333 de-identified patient safety event reports from two independent sources. Based on the extracted information, we further evaluated how optimized information presentation could help facilitate the disclosure of system vulnerabilities in traditional RCA. RESULTS: Multilabel text classification is effective in identifying safety-related information from the narrative description of patient safety events. The Pruned Sets in conjunction with Naïve Bayes are the outperformed algorithm in one dataset, with an overall F score of 60.0 % and the highest F score of 96.0 % for identifying "Adverse Drug Reaction". The Classifier Chains in conjunction with Naïve Bayes are the outperformed algorithm in another dataset, with an overall F score of 43.2 % and the highest F score of 64.0 % for identifying "Medication". During the RCA, human experts applied the optimized presentation of information which showed advantages of identifying system vulnerabilities. CONCLUSION: Our study demonstrated the feasibility of using multilabel text classification for identifying safety-related information from the narrative description of patient safety events. The extracted information when grouped by safety-related information can better aid human experts to conduct systems-centered RCA and disclose system vulnerabilities.

19.
Biotechnol Biofuels ; 12: 278, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827606

RESUMO

Background: Xylanase is one of the most extensively used biocatalysts for biomass degradation. However, its low catalytic efficiency and poor thermostability limit its applications. Therefore, improving the properties of xylanases to enable synergistic degradation of lignocellulosic biomass with cellulase is of considerable significance in the field of bioenergy. Results: Using fragment replacement, we improved the catalytic performance and thermostability of a GH10 xylanase, XylE. Of the ten hybrid enzymes obtained, seven showed xylanase activity. Substitution of fragments, M3, M6, M9, and their combinations enhanced the catalytic efficiency (by 2.4- to fourfold) as well as the specific activity (by 1.2- to 3.3-fold) of XylE. The hybrids, XylE-M3, XylE-M3/M6, XylE-M3/M9, and XylE-M3/M6/M9, showed enhanced thermostability, as observed by the increase in the T 50 (3-4.7 °C) and T m (1.1-4.7 °C), and extended t 1/2 (by 1.8-2.3 h). In addition, the synergistic effect of the mutant xylanase and cellulase on the degradation of mulberry bark showed that treatment with both XylE-M3/M6 and cellulase exhibited the highest synergistic effect. In this case, the degree of synergy reached 1.3, and the reducing sugar production and dry matter reduction increased by 148% and 185%, respectively, compared to treatment with only cellulase. Conclusions: This study provides a successful strategy to improve the catalytic properties and thermostability of enzymes. We identified several xylanase candidates for applications in bioenergy and biorefinery. Synergistic degradation experiments elucidated a possible mechanism of cellulase inhibition by xylan and xylo-oligomers.

20.
Biotechnol Biofuels ; 12: 279, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827607

RESUMO

Background: Regarding plant cell wall polysaccharides degradation, multimodular glycoside hydrolases (GHs) with two catalytic domains separated by one or multiple carbohydrate-binding domains are rare in nature. This special mode of domain organization endows the Caldicellulosiruptor bescii CelA (GH9-CBM3c-CBM3b-CBM3b-GH48) remarkably high efficiency in hydrolyzing cellulose. CbXyn10C/Cel48B from the same bacterium is also such an enzyme which has, however, evolved to target both xylan and cellulose. Intriguingly, the GH10 endoxylanase and GH48 cellobiohydrolase domains are both dual functional, raising the question if they can act synergistically in hydrolyzing cellulose and xylan, the two major components of plant cell wall. Results: In this study, we discovered that CbXyn10C and CbCel48B, which stood for the N- and C-terminal catalytic domains, respectively, cooperatively released much more cellobiose and cellotriose from cellulose. In addition, they displayed intramolecular synergy but only at the early stage of xylan hydrolysis by generating higher amounts of xylooligosaccharides including xylotriose, xylotetraose, and xylobiose. When complex lignocellulose corn straw was used as the substrate, the synergy was found only for cellulose but not xylan hydrolysis. Conclusion: This is the first report to reveal the synergy between a GH10 and a GH48 domain. The synergy discovered in this study is helpful for understanding how C. bescii captures energy from these recalcitrant plant cell wall polysaccharides. The insight also sheds light on designing robust and multi-functional enzymes for plant cell wall polysaccharides degradation.

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