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1.
J Biol Chem ; 300(4): 107123, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38417796

ABSTRACT

Thiram is a toxic fungicide extensively used for the management of pathogens in fruits. Although it is known that thiram degrades in plant tissues, the key enzymes involved in this process remain unexplored. In this study, we report that a tau class glutathione S-transferase (GST) from Carica papaya can degrade thiram. This enzyme was easily obtained by heterologous expression in Escherichia coli, showed low promiscuity toward other thiuram disulfides, and catalyzed thiram degradation under physiological reaction conditions. Site-directed mutagenesis indicated that G-site residue S67 shows a key influence for the enzymatic activity toward thiram, while mutation of residue S13, which reduced the GSH oxidase activity, did not significantly affect the thiram-degrading activity. The formation of dimethyl dithiocarbamate, which was subsequently converted into carbon disulfide, and dimethyl dithiocarbamoylsulfenic acid as the thiram degradation products suggested that thiram undergoes an alkaline hydrolysis that involves the rupture of the disulfide bond. Application of the GST selective inhibitor 4-chloro-7-nitro-2,1,3-benzoxadiazole reduced papaya peel thiram-degrading activity by 95%, indicating that this is the main degradation route of thiram in papaya. GST from Carica papaya also catalyzed the degradation of the fungicides chlorothalonil and thiabendazole, with residue S67 showing again a key influence for the enzymatic activity. These results fill an important knowledge gap in understanding the catalytic promiscuity of plant GSTs and reveal new insights into the fate and degradation products of thiram in fruits.


Subject(s)
Carica , Glutathione Transferase , Thiram , Carica/enzymology , Carica/genetics , Fungicides, Industrial/metabolism , Glutathione Transferase/metabolism , Glutathione Transferase/genetics , Glutathione Transferase/chemistry , Mutagenesis, Site-Directed , Plant Proteins/chemistry , Plant Proteins/genetics , Plant Proteins/metabolism , Thiram/metabolism , Escherichia coli/genetics , Recombinant Proteins/genetics , Recombinant Proteins/metabolism
2.
J Nat Prod ; 87(6): 1540-1547, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38832657

ABSTRACT

Phenazines are aromatic compounds with antifungal and cytotoxic activities. Phenazines incorporating phenazine 1-carboxylic acid have widespread applications in agriculture, medicine, and industry. Griseoluteic acid is a cytotoxic compound secreted by Streptomyces griseoluteus P510, displaying potential medical applications. However, the biosynthetic pathway of griseoluteic acid has not been elucidated, limiting its development and application. In this study, a conserved phenazine biosynthetic gene cluster of S. griseoluteus P510 was identified through genomic analysis. Subsequently, its was confirmed that the four essential modification enzymes SgpH, SgpI, SgpK, and SgpL convert phenazine-1,6-dicarboxylic acid into griseoluteic acid by heterologous expression in Escherichia coli. Moreover, the biosynthetic pathway of griseoluteic acid was established in Pseudomonas chlororaphis characterized by a high growth rate and synthesis efficiency of phenazines, laying the foundation for the efficient production of griseoluteic acid.


Subject(s)
Phenazines , Phenazines/metabolism , Phenazines/chemistry , Molecular Structure , Multigene Family , Biosynthetic Pathways , Streptomyces/metabolism , Streptomyces/genetics , Streptomyces griseus/metabolism , Pseudomonas chlororaphis/metabolism , Escherichia coli/metabolism
3.
Appl Microbiol Biotechnol ; 108(1): 54, 2024 Dec.
Article in English | MEDLINE | ID: mdl-38175240

ABSTRACT

Hyaluronidases catalyze the degradation of hyaluronan (HA), which is finding rising applications in medicine, cosmetic, and food industries. Recombinant expression of hyaluronidases in microbial hosts has been given special attention as a sustainable way to substitute animal tissue-derived hyaluronidases. In this study, we focused on optimizing the secretion of hyaluronidase from Homo sapiens in Pichia pastoris by secretion pathway engineering. The recombinant hyaluronidase was first expressed under the control of a constitutive promoter PGCW14. Then, two endoplasmic reticulum-related secretory pathways were engineered to improve the secretion capability of the recombinant strain. Signal peptide optimization suggested redirecting the protein into co-translational translocation using the ost1-proα signal sequence improved the secretion level by 20%. Enhancing the co-translational translocation by overexpressing signal recognition particle components further enhanced the secretory capability by 48%. Then, activating the unfolded protein response by overexpressing a transcriptional factor ScHac1p led to a secreted hyaluronidase activity of 4.06 U/mL, which was 2.1-fold higher than the original strain. Finally, fed-batch fermentation elevated the production to 19.82 U/mL. The combined engineering strategy described here could be applied to enhance the secretion capability of other proteins in yeast hosts. KEY POINTS: • Improving protein secretion by enhancing co-translational translocation in P. pastoris was reported for the first time. • Overexpressing Hac1p homologous from different origins improved the rhPH-20 secretion. • A 4.9-fold increase in rhPH-20 secretion was achieved after fermentation optimization and fed-batch fermentation.


Subject(s)
Hyaluronoglucosaminidase , Unfolded Protein Response , Animals , Humans , Hyaluronoglucosaminidase/genetics , Protein Transport , Endoplasmic Reticulum
4.
Angew Chem Int Ed Engl ; 63(29): e202404314, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-38712987

ABSTRACT

Atomically precise low-nuclearity (n<10) silver nanoclusters (AgNCs) have garnered significant interest due to their size-dependent optical properties and diverse applications. However, their synthesis has remained challenging, primarily due to their inherent instability. The present study introduces a new feasible approach for clustering silver ions utilizing highly negative and redox-inert polyoxoniobates (PONbs) as all-inorganic ligands. This strategy not only enables the creation of novel Ag-PONb composite nanoclusters but also facilitates the synthesis of stable low-nuclearity AgNCs. Using this method, we have successfully synthesized a small octanuclear rhombic [Ag8]6+ AgNC stabilized by six highly negative [LiNb27O75]14- polyoxoanions. This marks the first PONb-protected superatomic AgNC, designated as {Ag8@(LiNb27O75)6} (Ag8@Nb162), with an aesthetically spherical core-shell structure. The crystalline Ag8@Nb162 is stable under ambient conditions, What's more, it is water-soluble and able to maintain its molecular cluster structure intact in water. Further, the stable small [Ag8]6+ AgNC has interesting temperature- and pH-dependent reversible fluorescence response, based on which a multiple optical encryption mode for anti-counterfeit technology was demonstrated. This work offers a promising avenue for the synthesis of fascinating and stable PONb-protected AgNCs and sheds light on the development of new-type optical functional materials.

5.
Zhongguo Dang Dai Er Ke Za Zhi ; 26(1): 48-53, 2024 Jan 15.
Article in Zh | MEDLINE | ID: mdl-38269459

ABSTRACT

OBJECTIVES: To investigate the clinical characteristics and risk factors of delayed bleeding after intestinal polypectomy in children, and to provide a theoretical basis for clinical surgical intervention of intestinal polyps. METHODS: A retrospective analysis was conducted on the clinical data of 2 456 children with intestinal polyps who underwent endoscopic high-frequency electrocoagulation loop resection in the Endoscopy Center of Children's Hospital Affiliated to Zhengzhou University from January 2014 to December 2021. According to the presence or absence of delayed bleeding after surgery, they were divided into bleeding group with 79 children and non-bleeding group with 2 377 children. A multivariate logistic regression analysis was used to investigate the risk factors for delayed bleeding. The receiver operating characteristic (ROC) curve was used to investigate the value of various indicators in predicting delayed bleeding. RESULTS: Of all 2 456 children, 79 (3.22%) experienced delayed bleeding, among whom 5 children with severe delayed bleeding underwent emergency colonoscopy for hemostasis and 74 received conservative treatment, and successful hemostasis was achieved for all children. There were significant differences between the bleeding and non-bleeding groups in age, body mass index, constipation rate, location of lesion, time of endoscopic procedure, resection method (P<0.05). Children with a diameter of polyps of 6-10 mm and >20 mm were more likely to develop delayed bleeding after resection (P<0.05). The multivariate logistic regression analysis showed that endoscopic operation time, polyp diameter, and resection method were significantly associated with delayed bleeding (P<0.05). The ROC curve analysis showed that the endoscopic operation time, polyp diameter, and resection method had a good value in predicting delayed bleeding after intestinal polypectomy, with an area under the ROC curve of 0.706, 0.688, and 0.627, respectively. CONCLUSIONS: Endoscopic high-frequency electrocoagulation loop resection has a lower incidence of delayed bleeding in children with intestinal polyps, and the endoscopic operation time, polyp diameter, and resection method are closely associated with the occurrence of postoperative delayed bleeding.


Subject(s)
Hemorrhage , Intestines , Child , Humans , Retrospective Studies , Intestinal Polyps/surgery , Risk Factors
6.
Cancer Immunol Immunother ; 72(7): 2045-2056, 2023 Jul.
Article in English | MEDLINE | ID: mdl-36795124

ABSTRACT

Immunotherapy based on immune checkpoint inhibitors (ICIs) has provided revolutionary results in treating various cancers. However, its efficacy in colorectal cancer (CRC), especially in microsatellite stability-CRC, is limited. This study aimed to observe the efficacy of personalized neoantigen vaccine in treating MSS-CRC patients with recurrence or metastasis after surgery and chemotherapy. Candidate neoantigens were analyzed from whole-exome and RNA sequencing of tumor tissues. The safety and immune response were assessed through adverse events and ELISpot. The clinical response was evaluated by progression-free survival (PFS), imaging examination, clinical tumor marker detection, circulating tumor DNA (ctDNA) sequencing. Changes in health-related quality of life were measured by the FACT-C scale. A total of six MSS-CRC patients with recurrence or metastasis after surgery and chemotherapy were administered with personalized neoantigen vaccines. Neoantigen-specific immune response was observed in 66.67% of the vaccinated patients. Four patients remained progression-free up to the completion of clinical trial. They also had a significantly longer progression-free survival time than the other two patients without neoantigen-specific immune response (19 vs. 11 months). Changes in health-related quality of life improved for almost all patients after the vaccine treatment. Our results shown that personalized neoantigen vaccine therapy is likely to be a safe, feasible and effective strategy for MSS-CRC patients with postoperative recurrence or metastasis.


Subject(s)
Cancer Vaccines , Colorectal Neoplasms , Humans , Antigens, Neoplasm , Cancer Vaccines/therapeutic use , Colorectal Neoplasms/genetics , Immunotherapy/methods , Immunotherapy, Active , Microsatellite Repeats , Quality of Life
7.
Neuroendocrinology ; 113(1): 80-91, 2023.
Article in English | MEDLINE | ID: mdl-36030776

ABSTRACT

INTRODUCTION: Fat mass and obesity-associated (FTO) gene is strongly associated with obesity which brings a major health threat. Altered expression of its encoded protein FTO in the hypothalamus has been identified to contribute to central control of appetite and body weight. However, its molecular mechanisms remain elusive. METHODS: Mouse hypothalamic POMC cell line N43/5 was treated with FTO inhibitor rhein, FTO shRNA, or extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor U0126 to inhibit FTO or ERK1/2. Rhein and U0126 were injected into lateral ventricle of the mice by intracerebroventricular cannulation. Western blotting and immunofluorescent assays were performed to monitor protein level. RESULTS: This study identified that inhibition of FTO in N43/5 cells led to phosphorylation of signal transducer and activator of transcription 3 (STAT3) at S727 site and induced p-STAT3-S727 nuclear translocation. We further showed that FTO inhibition promoted phosphorylation of ERK1/2; specific inhibition of ERK1/2 signaling by U0126 could abolish the effect of FTO inhibition on STAT3-S727 phosphorylation and nuclear translocation. Furthermore, we found that inhibition of hypothalamic FTO promoted STAT3-S727 phosphorylation in the hypothalamic arcuate nucleus, and the mice showed reductions in food intake and body weight. In addition, inhibition of hypothalamic ERK1/2 could abolish the effects of FTO inhibition on STAT3-S727 phosphorylation, reductions of food intake and body weight. CONCLUSION: Our in vitro and in vivo data suggest that the inhibition of hypothalamic FTO could activate STAT3 through ERK1/2, which is potentially associated with reductions in food intake and body weight.


Subject(s)
MAP Kinase Signaling System , STAT3 Transcription Factor , Mice , Animals , STAT3 Transcription Factor/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Hypothalamus/metabolism , Body Weight , Obesity/metabolism , Eating , Phosphorylation , Leptin/metabolism , Alpha-Ketoglutarate-Dependent Dioxygenase FTO/metabolism
8.
J Org Chem ; 88(24): 16906-16914, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-38019102

ABSTRACT

A stereoselective and environmentally friendly thiolation of terminal alkynes was reported. Thiuram disulfide reagents (tetramethylthiuram disulfide and tetraethylthiuram disulfide) that reacted with alkynes in dimethyl sulfoxide (DMSO)/H2O could give (Z)-vinyl sulfides in good yields (up to 88%). This protocol features broad substrate scope, good stereoselectivity, high atom economy, good yields, and is transition metal-free. Mechanistic studies revealed that water and DMSO served as hydrogen sources, which greatly highlighted the unique reactivity of this special reaction involving two H-atom donors.

9.
Microb Ecol ; 85(4): 1288-1299, 2023 May.
Article in English | MEDLINE | ID: mdl-35522265

ABSTRACT

Microbial co-culture simulates the natural ecosystem through the combination of artificial microbes. This approach has been widely applied in the study of activating silent genes to reveal novel secondary metabolites. However, there are still challenges in determining the biosynthetic pathways. In this study, the effects of microbial co-culture on the morphology of the microbes were verified by the morphological observation. Subsequently, through the strategy combining substrate feeding, stable isotope labeling, and gene expression analysis, the biosynthetic pathways of five benzoic acid derivatives N1-N4 and N7 were demonstrated: the secondary metabolite 10-deoxygerfelin of A. sydowii acted as an inducer to induce B. subtilis to produce benzoic acid, which was further converted into 3-OH-benzoic acid by A. sydowii. Subsequently, A. sydowii used 3-OH-benzoic acid as the substrate to synthesize the new compound N2, and then N1, N3, N4, and N7 were biosynthesized upon the upregulation of hydrolase, hydroxylase, and acyltransferase during co-culture. The plate zone analysis suggested that the biosynthesis of the newly induced compounds N1-N4 was mainly attributed to A. sydowii, and both A. sydowii and B. subtilis were indispensable for the biosynthesis of N7. This study provides an important basis for a better understanding of the interactions among microorganisms, providing new ideas for studying the biosynthetic pathways of the newly induced secondary metabolites in co-culture.


Subject(s)
Bacillus subtilis , Ecosystem , Bacillus subtilis/genetics , Coculture Techniques , Benzoic Acid
10.
Macromol Rapid Commun ; 44(8): e2300014, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36790071

ABSTRACT

Inverse vulcanization utilizes an organic compound as reagent for crosslinking elemental sulfur to result in corresponding polymeric material with a high sulfur content. This work, employing 1,3,5-triisopropylbenzene (TIPB) as the reagent, demonstrates the first attempt on extending the scope of crosslinking agents of inverse vulcanization to saturate compounds. Under nuclear magnetic spectroscopic analysis, the reactions between TIPB and elemental sulfur take places through ring-opening reaction of S8 resulting in sulfur radicals at sulfur chain ends, radicals transferring to isopropyl groups of TIPB, and radical coupling reactions between carbon radicals and sulfur radicals. The obtained products are similar to the sulfur polymers from conventional inverse vulcanization processes and show self-healing property.


Subject(s)
Organic Chemicals , Sulfur , Indicators and Reagents , Sulfur/chemistry , Polymers/chemistry , Carbon
11.
Mar Drugs ; 21(1)2023 Jan 11.
Article in English | MEDLINE | ID: mdl-36662220

ABSTRACT

Antarctic krill is a crucial marine resource containing plenty of high-valued nutrients. However, krill oil as a single product has been developed by the current solvent extraction with high cost. From the perspective of comprehensive utilization of Antarctic krill, this study proposed a novel two-step enzymolysis-assisted extraction in attempt to produce value-added oil and enzymolysate simultaneously. After two-step chitinase/protease hydrolysis, the lipid yield increased from 2.09% to 4.18%, reaching 112% of Soxhlet extraction. The method greatly improved the yields of main components while reducing the impurity content without further refining. After optimization, the oil contained 246.05 mg/g of phospholipid, 80.96 mg/g of free eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and 0.82 mg/g of astaxanthin. The by-product enzymolysate was abundant in water-soluble proteins (34.35 mg/g), oligopeptides (13.92 mg/g), amino acids (34.24 mg/g), and carbohydrates (5.79 mg/g), which was a good source of functional nutrients. In addition, both oil and enzymolysate showed high antioxidant capacity. This novel method could simultaneously provide oil and enzymolysate amounting for 58.61% of dried krill.


Subject(s)
Euphausiacea , Animals , Euphausiacea/chemistry , Eicosapentaenoic Acid/chemistry , Phospholipids , Oils/chemistry , Antioxidants/chemistry
12.
Molecules ; 28(22)2023 Nov 11.
Article in English | MEDLINE | ID: mdl-38005263

ABSTRACT

Photocatalytic technology for inactivating bacteria in water has received much attention. In this study, we reported a dark-light dual-mode sterilized g-C3N4/chitosan/poly (vinyl alcohol) hydrogel (g-CP) prepared through freeze-thaw cycling and an in situ electron-beam radiation method. The structures and morphologies of g-CP were confirmed using Fourier infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), solid ultraviolet diffuse reflectance spectroscopy (UV-vis DRS), and Brunauer-Emmett-Teller (BET). Photocatalytic degradation experiments demonstrated that 1 wt% g-CP degraded rhodamine B (RhB) up to 65.92% in 60 min. At the same time, g-CP had good antimicrobial abilities for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) within 4 h. The shapes of g-CP were adjustable (such as bar, cylinder, and cube) and had good mechanical properties and biocompatibility. The tensile and compressive modulus of 2 wt% g-CP were 0.093 MPa and 1.61 MPa, respectively. The Cell Counting Kit-8 (CCK-8) test and Hoechst33342/PI double staining were used to prove that g-CP had good biocompatibility. It is expected to be applied to environmental sewage treatment and wound dressing in the future.


Subject(s)
Escherichia coli , Staphylococcus aureus , Nanogels , Electrons , Microscopy, Electron, Scanning
13.
Brief Bioinform ; 21(5): 1776-1786, 2020 09 25.
Article in English | MEDLINE | ID: mdl-31686106

ABSTRACT

Genes are unique in functional role and differ in their sensitivities to genetic defects, but with difficulties in pathogenicity prediction. This study attempted to improve the performance of existing in silico algorithms and find a common solution based on individualization strategy. We initiated the individualization with the epilepsy-related SCN1A variants by sub-regional stratification. SCN1A missense variants related to epilepsy were retrieved from mutation databases, and benign missense variants were collected from ExAC database. Predictions were performed by using 10 traditional tools with stepwise optimizations. Model predictive ability was evaluated using the five-fold cross-validations on variants of SCN1A, SCN2A, and KCNQ2. Additional validation was performed in SCN1A variants of damage-confirmed/familial epilepsy. The performance of commonly used predictors was less satisfactory for SCN1A with accuracy less than 80% and varied dramatically by functional domains of Nav1.1. Multistep individualized optimizations, including cutoff resetting, domain-based stratification, and combination of predicting algorithms, significantly increased predictive performance. Similar improvements were obtained for variants in SCN2A and KCNQ2. The predictive performance of the recently developed ensemble tools, such as Mendelian clinically applicable pathogenicity, combined annotation-dependent depletion and Eigen, was also improved dramatically by application of the strategy with molecular sub-regional stratification. The prediction scores of SCN1A variants showed linear correlations with the degree of functional defects and the severity of clinical phenotypes. This study highlights the need of individualized optimization with molecular sub-regional stratification for each gene in practice.


Subject(s)
Genetic Variation , Computer Simulation , Databases, Genetic , Humans , KCNQ2 Potassium Channel/genetics , NAV1.1 Voltage-Gated Sodium Channel/genetics , NAV1.2 Voltage-Gated Sodium Channel/genetics
14.
Cell Mol Neurobiol ; 42(3): 777-790, 2022 Apr.
Article in English | MEDLINE | ID: mdl-33058074

ABSTRACT

Arachidonic acid (AA), a polyunsaturated fatty acid, is involved in the modulation of neuronal excitability in the brain. Arachidonate lipoxygenase 3 (ALOXE3), a critical enzyme in the AA metabolic pathway, catalyzes the derivate of AA into hepoxilins. However, the expression pattern of ALOXE3 and its role in the brain has not been described until now. Here we showed that the levels of Aloxe3 mRNA and protein kept increasing since birth and reached the highest level at postnatal day 30 in the mouse hippocampus and temporal cortex. Histomorphological analyses indicated that ALOXE3 was enriched in adult hippocampus, somatosensory cortex and striatum. The distribution was restricted to the neurites of function-specific subregions, such as mossy fibre connecting hilus and CA3 neurons, termini of Schaffer collateral projections, and the layers III and IV of somatosensory cortex. The spatiotemporal expression pattern of ALOXE3 suggests its potential role in the modulation of neural excitability and seizure susceptibility. In fact, decreased expression of ALOXE3 and elevated concentration of AA in the hippocampus was found after status epilepticus (SE) induced by pilocarpine. Local overexpression of ALOXE3 via adeno-associated virus gene transfer restored the elevated AA level induced by SE, alleviated seizure severities by increasing the latencies to myclonic switch, clonic convulsions and tonic hindlimb extensions, and decreased the mortality rate in the pilocarpine-induced SE model. These results suggest that the expression of ALOXE3 is a crucial regulator of AA metabolism in brain, and potentially acts as a regulator of neural excitability, thereby controlling brain development and seizure susceptibility.


Subject(s)
Seizures , Status Epilepticus , Animals , Brain/metabolism , Hippocampus/metabolism , Mice , Pilocarpine , Seizures/chemically induced , Seizures/genetics , Seizures/metabolism , Status Epilepticus/chemically induced
15.
Mol Biol Rep ; 49(4): 2857-2867, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35067814

ABSTRACT

BACKGROUND: Intestinal ischemia-reperfusion (I/R) causes severe injury to the intestine, leading to systemic inflammation and multiple organ failure. Autophagy is a stress-response mechanism that can protect against I/R injury by removing damaged organelles and toxic protein aggregates. Recent evidence has identified JAK-STAT signaling pathway as a new regulator of autophagy process, however, their regulatory relationship in intestinal I/R remains unknown. METHODS AND RESULTS: We systematically analyzed intestinal transcriptome data and found that JAK-STAT pathway was largely activated in response to I/R with most significant upregulation observed for JAK2 and STAT3. ChIP-Seq and luciferase assays in an in vitro oxygen-glucose deprivation and reoxygenation model revealed that activated JAK2/STAT3 signaling directly inhibited the transcription of autophagy regulator Beclin-1, leading to the suppression of autophagy and the activation of intestinal cell death. These findings were further confirmed in an in vivo mouse model, in which, intestinal I/R injury was associated with the activation of JAK2/STAT3 pathway and the deactivation of Beclin-1-mediated autophagy, while inhibiting JAK2/STAT3 with AG490 reactivated autophagy and improved survival after intestinal I/R injury. CONCLUSIONS: JAK2/STAT3 signaling suppresses autophagy process during intestinal I/R, while inhibiting JAK-STAT can be protective against intestinal I/R injury by activating autophagy. These findings expand our knowledge on intestinal I/R injury and provide therapeutic targets for clinical treatment.


Subject(s)
Janus Kinases , Reperfusion Injury , Animals , Apoptosis , Autophagy , Intestines , Janus Kinase 2/metabolism , Janus Kinases/metabolism , Mice , Reperfusion Injury/drug therapy , Reperfusion Injury/genetics , Reperfusion Injury/metabolism , STAT Transcription Factors/metabolism , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/metabolism , Signal Transduction
16.
J Appl Microbiol ; 133(5): 2790-2801, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35870153

ABSTRACT

AIMS: Phenazines, such as phenazine-1-carboxylic acid (PCA), phenazine-1-carboxamide (PCN), 2-hydroxyphenazine-1-carboxylic acid (2-OH-PCA), 2-hydroxyphenazine (2-OH-PHZ), are a class of secondary metabolites secreted by plant-beneficial Pseudomonas. Ps. chlororaphis GP72 utilizes glycerol to synthesize PCA, 2-OH-PCA and 2-OH-PHZ, exhibiting broad-spectrum antifungal activity. Previous studies showed that the addition of dithiothreitol (DTT) could increase the phenazines production in Ps. chlororaphis GP72AN. However, the mechanism of high yield of phenazine by adding DTT is still unclear. METHODS AND RESULTS: In this study, untargeted and targeted metabolomic analysis were adopted to determine the content of metabolites. The results showed that the addition of DTT to GP72AN affected the content of metabolites of central carbon metabolism, shikimate pathway and phenazine competitive pathway. Transcriptome analysis was conducted to investigate the changed cellular process, and the result indicated that the addition of DTT affected the expression of genes involved in phenazine biosynthetic cluster and genes involved in phenazine competitive pathway, driving more carbon flux into phenazine biosynthetic pathway. Furthermore, genes involved in antioxidative stress, phosphate transport system and mexGHI-opmD efflux pump were also affected by adding DTT. CONCLUSION: This study demonstrated that the addition of DTT altered the expression of genes related to phenazine biosynthesis, resulting in the change of metabolites involved in central carbon metabolism, shikimate pathway and phenazine competitive pathway. SIGNIFICANCE AND IMPACT OF THE STUDY: This work expands the understanding of high yield of phenazine by the addition of DTT and provides several targets for increasing phenazine production.


Subject(s)
Pseudomonas chlororaphis , Pseudomonas chlororaphis/genetics , Pseudomonas chlororaphis/metabolism , Glycerol/metabolism , Antifungal Agents/metabolism , Dithiothreitol/metabolism , Transcriptome , Phenazines/metabolism , Metabolomics , Gene Expression Profiling , Carbon/metabolism , Phosphates/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism
17.
Neoplasma ; 69(1): 193-202, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34779642

ABSTRACT

Pancreatic ductal adenocarcinoma is a complex gastrointestinal tumor with high metastatic potential and poor prognosis. Actin-binding protein Girdin is highly expressed in a variety of tumors and promotes tumorigenesis and progression. However, the mechanisms underlying the involvement of Girdin in pancreatic cancer have not been clarified. In this study, we observed that the expression of Girdin was upregulated in pancreatic cancer cells. The siRNA-mediated gene knockdown experiments showed that reduced expression of Girdin in pancreatic cancer cells inhibited cell proliferation, migration, and invasion while promoting cell apoptosis. Functional assays revealed that c-MYC overexpression in pancreatic cancer cells could significantly increase the cell proliferation ability and rates of cell migration and invasion while decreasing the apoptosis rate. It has been shown that phosphorylation plays a role in the functional regulation of the c-MYC gene. Subsequently, we examined the expression level of c-MYC in cells with manipulated expression of Girdin and identified a positive correlation between Girdin expression and c-MYC expression. Moreover, we found that Girdin knockdown in c-MYC-overexpressing pancreatic cancer cells slowed cell growth, blocked the cell cycle progression, significantly promoted apoptosis, and markedly decreased the cell migration and invasion. This finding indicated that silencing Girdin could mitigate the effect of c-MYC on promoting proliferation and metastasis of pancreatic cancer. Overall, this study provided evidence that Girdin promoted pancreatic cancer development presumably by regulating the c-MYC overexpression.


Subject(s)
Genes, myc , Pancreatic Neoplasms , Cell Line, Tumor , Cell Movement , Cell Proliferation , Gene Expression Regulation, Neoplastic , Humans , Pancreatic Neoplasms/genetics , Vesicular Transport Proteins/genetics , Vesicular Transport Proteins/metabolism
18.
Sensors (Basel) ; 22(14)2022 Jul 19.
Article in English | MEDLINE | ID: mdl-35891051

ABSTRACT

In this letter, we propose a nonlinear Magnetoelastic Energy (ME) with a material parameter related to electron interactions. An attenuating term is contained in the formula of the proposed nonlinear ME, which can predict the variation in the anisotropic magneto-crystalline constants induced by external stress more accurately than the classical linear ME. The domain wall velocity under stress and magnetic field can be predicted accurately based on the nonlinear ME. The proposed nonlinear ME model is concise and easy to use. It is important in sensor analysis and production, magneto-acoustic coupling motivation, magnetoelastic excitation, etc.

19.
Angew Chem Int Ed Engl ; 61(43): e202212253, 2022 Oct 24.
Article in English | MEDLINE | ID: mdl-36082671

ABSTRACT

Coordination-driven crosslinking networks with reversible and dynamic characteristics are gaining increasing interest in diverse application fields. Herein, we use a coordination crosslinking approach using metal-organic polyhedra (MOPs) as high-connectivity building blocks to post-assemble a class of coordination hypercrosslinked MOP (CHMOP) polymers. The introduction of 12-connected MOP nodes to the polymeric networks is critical to producing membranes that overcome the trade-off between mechanical properties and dynamic healing, and meanwhile possess multifunctionalities including shape memory, solution processability, and 3D printing. The CHMOPs can also be used for anticorrosion coating and achieve function couplings, e.g., shape memory-assisted self-healing (SMASH), which have not been achieved in the MOP-based hybrid materials yet. This work not only offers a feasible strategy to construct new multifunctional materials but also greatly expands the application scopes of MOPs.

20.
Cell Mol Neurobiol ; 41(6): 1257-1269, 2021 Aug.
Article in English | MEDLINE | ID: mdl-32500354

ABSTRACT

Valproate (VPA), a widely-used antiepileptic drug, is a selective inhibitor of histone deacetylase (HDAC) that play important roles in epigenetic regulation. The patient with different diseases receiving this drug tend to exhibit weight gain and abnormal metabolic phenotypes, but the underlying mechanisms remain largely unknown. Here we show that VPA increases the Fto mRNA and protein expression in mouse hypothalamic GT1-7 cells. Interestingly, VPA promotes histone H3/H4 acetylation and the FTO expression which could be reversed by C646, an inhibitor for histone acetyltransferase. Furthermore, VPA weakens the FTO's binding and enhances the binding of transcription factor TAF1 to the Fto promoter, and C646 leads to reverse effect of the VPA, suggesting an involvement of the dynamic of histone H3/H4 acetylation in the regulation of FTO expression. In addition, the mice exhibit an increase in the food intake and body weight at the beginning of 2-week treatment with VPA. Simultaneously, in the hypothalamus of the VPA-treated mice, the FTO expression is upregulated and the H3/H4 acetylation is increased; further the FTO's binding to the Fto promoter is decreased and the TAF1's binding to the promoter is enhanced, suggesting that VPA promotes the assembly of the basal transcriptional machinery of the Fto gene. Finally, the inhibitor C646 could restore the effects of VPA on FTO expression, H3/H4 acetylation, body weight, and food intake; and loss of FTO could reverse the VPA-induced increase of body weight and food intake. Taken together, this study suggests an involvement of VPA in the epigenetic upregulation of hypothalamic FTO expression that is potentially associated with the VPA-induced weight gain.


Subject(s)
Alpha-Ketoglutarate-Dependent Dioxygenase FTO/biosynthesis , Epigenesis, Genetic/drug effects , Hypothalamus/drug effects , Hypothalamus/metabolism , Valproic Acid/pharmacology , Weight Gain/drug effects , Animals , Anticonvulsants/pharmacology , Dose-Response Relationship, Drug , Eating/drug effects , Eating/physiology , Epigenesis, Genetic/physiology , Gene Expression , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Up-Regulation/drug effects , Up-Regulation/physiology , Weight Gain/physiology
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