ABSTRACT
BACKGROUND: Selection markers are useful in genetic modification of yeast Pichia pastoris. However, the leakage of the promoter caused undesired expression of selection markers especially those toxic proteins like MazF, halting the cell growth and hampering the genetic manipulation in procaryotic system. In this study, a new counter-selectable marker-based strategy has been established for seamless modification with high efficiency and low toxicity. RESULTS: At first, the leaky expression of the enhanced green fluorescent protein (EGFP) as a reporter gene under the control of six inducible promoters of P. pastoris was investigated in two hosts Escherichia coli and P. pastoris, respectively. The results demonstrated that the DAS1 and FDH1 promoters (PDAS1 and PFDH1) had the highest leakage expression activities in procaryotes and eukaryotes, and the DAS2 promoter (PDAS2) was inducible with medium strength but low leakage expression activity, all of which were selected for further investigation. Next, Mirabilis antiviral proteins (MAPs) c21873-1, c21873-1T (truncated form of c21873-1) and c23467 were mined as the new counter-selectable markers, and hygromycin B (Hyg B) resistance gene was used as the positive-selectable marker, respectively. Then, modular plasmids with MAP-target gene-Hyg B cassettes were constructed and used to transform into P. pastoris cells after linearization, and the target genes were integrated into its genome at the BmT1 locus through single-crossover homologous recombination (HR). After counter-selection induced by methanol medium, the markers c21873-1 and c21873-1T were recycled efficiently. But c23467 failed to be recycled due to its toxic effect on the P. pastoris cells. At last, the counter-selectable marker c21873-1 under the tightly regulated PDAS2 enabled the encoding genes of reporter EGFP and tested proteins to be integrated into the target locus and expressed successfully. CONCLUSIONS: We have developed MAP c21873-1 as a novel counter-selectable marker which could perform efficient gene knock-in by site-directed HR. Upon counter-selection, the marker could be recycled for repeated use, and no undesirable sequences were introduced except for the target gene. This unmarked genetic modification strategy may be extended to other genetic modification including but not limited to gene knock-out and site-directed mutagenesis in future.
Subject(s)
Promoter Regions, Genetic , Escherichia coli/genetics , Escherichia coli/metabolism , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Genetic Markers , Saccharomycetales/genetics , Saccharomycetales/metabolismABSTRACT
AIMS: Multidrug resistance presents difficulties in preventing and treating bacterial infections. Proline-rich antimicrobial peptides (PrAMPs) inhibit bacterial growth by affecting the intracellular targets rather than by permeabilizing the membrane. The aim of this study was to develop a yeast-based fusion carrier system using calmodulin (CaM) and xylanase (XynCDBFV) as two carriers to express the model PrAMP PR-39-derived peptide (PR-39-DP) in Pichia pastoris. METHODS AND RESULTS: Fusion protein secreted into the culture supernatant was purified in a one-step on-column digestion using human rhinovirus 3C protease, obtaining the target peptide PR-39-DP. The growth curves of Escherichia coli were monitored by recording the OD600 values of the bacteria. The antibacterial activity of PR-39-DP was evaluated in killing assays performed on E. coli. The yield of PR-39-DP was 1.0-1.2 mg l-1 in the CaM fusion carrier system, approximately three times that of the XynCDBFV fusion carrier system. The minimal inhibitory concentration of PR-39-DP was â¼10.5 µg ml-1. CONCLUSIONS: CaM and XynCDBFV provide increased stability and promote the expression and secretion of active PR-39-DP.
Subject(s)
Carrier Proteins , Escherichia coli , Humans , Carrier Proteins/metabolism , Escherichia coli/metabolism , Pichia/genetics , Pichia/metabolism , Antimicrobial Cationic Peptides/pharmacology , Recombinant Proteins/genetics , Recombinant Proteins/metabolismABSTRACT
Globally, nearly half of patients with type 2 diabetes (T2D) do not successfully achieve target HbA1c with basal insulin, despite meeting fasting plasma glucose (FPG) targets. In this post hoc analysis of the LixiLan-L study, we determined whether iGlarLixi, a fixed-ratio combination of insulin glargine Gla-100 (iGlar) and the glucagon-like peptide-1 receptor agonist lixisenatide (Lixi), addresses the challenge of reducing residual hyperglycaemia in patients with T2D. In LixiLan-L, a randomized, open-label study, 1018 patients with T2D on basal insulin for ≥6 months ± oral antidiabetes drugs entered a 6-week run-in period, during which they were switched to and/or optimized for a daily dose of iGlar while continuing only metformin. Following the run-in period, 736 patients were then randomized to receive iGlarLixi or were continued on iGlar for 30 weeks ± metformin. Residual hyperglycaemia was defined as HbA1c ≥ 7.0% despite FPG of <140 mg/dL. The proportion of patients with residual hyperglycaemia was similar in both treatment arms at screening (~~42%), and increased after the run-in period (~~62%). After 30 weeks, the proportion of patients with residual hyperglycaemia declined to 23.8% in the iGlarLixi versus 47.1% in the iGlar arm (P < .0001). The proportion of patients achieving both HbA1c (<7.0%) and FPG (<140 mg/dL) targets was higher in the iGlarLixi compared with the iGlar arm (50.3% vs. 27.4%, respectively; P < .0001). iGlarLixi effectively reduces residual hyperglycaemia in patients with T2D on basal insulin therapy.
Subject(s)
Diabetes Mellitus, Type 2 , Hyperglycemia , Blood Glucose , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/drug therapy , Drug Combinations , Glycated Hemoglobin/analysis , Humans , Hyperglycemia/prevention & control , Hypoglycemic Agents/therapeutic use , Insulin Glargine/therapeutic useABSTRACT
AIM: To evaluate the efficacy of iGlarLixi by C-peptide levels and duration of diabetes in an exploratory analysis of the LixiLan-G study. METHODS: LixiLan-G was a 26-week, randomized, open-label study in adults with type diabetes (T2D) inadequately controlled while on a glucagon-like peptide-1 receptor agonist (GLP-1 RA), with metformin, with or without pioglitazone and/or a sodium-glucose co-transporter-2 inhibitor. This analysis investigated the efficacy of switching to iGlarLixi by fasting baseline quartile C-peptide levels and baseline quartile of duration of T2D compared with continued GLP-1 RA use. RESULTS: Change in glycated hemoglobin (HbA1c) from baseline to week 26 was significantly greater with iGlarLixi compared with continued GLP-1 RAs across all fasting C-peptide quartiles (-1.00% to -1.06% vs. -0.23% to -0.54% range, respectively) and irrespective of all T2D duration quartiles (-0.94% to -1.07% vs. -0.25% to -0.50% range). A significantly greater proportion of participants in the iGlarLixi arm achieved an HbA1c of <7% across all C-peptide quartiles (51%-73% range) than in the GLP-1 RA arm (19%-32% range). The greatest reductions in HbA1c in participants receiving iGlarLixi were observed in those with the shortest duration of disease, although consistently greater than reductions observed with continued GLP-1 RAs. Reductions in HbA1c were comparable across C-peptide quartiles within the iGlarLixi arm. CONCLUSIONS: The results of this study suggest that iGlarLixi is an effective treatment option, irrespective of C-peptide levels or duration of diabetes, in adults with insufficiently controlled T2D receiving GLP-1 RAs.
Subject(s)
Diabetes Mellitus, Type 2 , Adult , Blood Glucose , Diabetes Mellitus, Type 2/drug therapy , Drug Combinations , Glucagon-Like Peptide-1 Receptor , Glycated Hemoglobin/analysis , Humans , Hypoglycemic Agents/therapeutic use , Insulin Glargine , PeptidesABSTRACT
Berberine (BBR), a small alkaloid, is used as a hypoglycemic agent in China. Stachyose (Sta), a Rehmannia glutinosa oligosaccharide, acts as a prebiotic. This study aimed to evaluate whether BBR combined with Sta produced better glycometabolism than BBR alone, and explored the effects on gut microbiota and metabolomics. Type-2 diabetic db/db mice were administered BBR (100 mg/kg), Sta (200 mg/kg), or both by gavage once daily. Glucose metabolism, the balance of α- and ß-cells, and mucin-2 expression were ameliorated by combined treatment of BBR and Sta, with stronger effects than upon treatment with BBR alone. The microbial diversity and richness were altered after combined treatment and after treatment with BBR alone. The abundance of Akkermansia muciniphila was increased by combined treatment compared to treatment with BBR alone, while the levels of the metabolite all-trans-heptaprenyl diphosphate were decreased and the levels of fumaric acid were increased, which both showed a strong correlation with A. muciniphila. In summary, BBR combined with Sta produced better glycometabolism than BBR alone through modulating gut microbiota and fecal metabolomics, and may aid in the development of a novel pharmaceutical strategy for treating Type 2 diabetes mellitus.
Subject(s)
Berberine/therapeutic use , Diabetes Mellitus, Experimental/drug therapy , Feces/chemistry , Gastrointestinal Microbiome/drug effects , Metabolomics/methods , Oligosaccharides/therapeutic use , Animals , Berberine/pharmacology , Male , Mice , Oligosaccharides/pharmacologyABSTRACT
UDP-glucose 4-epimerase (UGE) is a universal enzyme responsible for interconversion of UDP-glucose and UDP-galactose. However, the gene encoding UGE from Davallia divaricate is elusive. In this study, two UGE genes, ddUGE1 and ddUGE2, were isolated and cloned from D. divaricate using a transcriptome-guided search strategy. Two unigenes sharing high sequence identity with UGE homologous genes were selected from transcriptome assembly. The enzymes, further functionally expressed in Escherichia coli, exhibit narrow substrate specificity. The biochemical characterization assays of DdUGE1 and DdUGE2 showed good thermal and pH stability, and metal ion independence, which provides a meaningful feature for biotechnological applications.[Formula: see text].
Subject(s)
UDPglucose 4-Epimerase , Uridine Diphosphate Galactose , DNA, Complementary , Escherichia coli , Molecular StructureABSTRACT
Diabetic dyslipidaemia is a major risk factor for accelerated atherosclerosis. Glycaemic treatments that improve dyslipidaemia may help reduce the burden of atherosclerosis. This analysis investigated the effect of iGlarLixi [insulin glargine U100 (iGlar) and lixisenatide] versus iGlar on lipid profiles in patients with type 2 diabetes uncontrolled on basal insulin. Data from LixiLan-L were used to estimate changes in fasting lipid levels from baseline to week 30, overall and in patients stratified by achievement of glycaemic targets {2-hour postprandial glucose [≤10, >10 mmoL/L], fasting plasma glucose [≤6.1, >6.1 mmoL/L], HbA1c [≤7, >7% (≤53, >53 mmol/mol)]}. At week 30, median percentage change in triglycerides remained nearly unchanged (0.3% increase) with iGlarLixi versus a 6.5% increase with iGlar (P = 0.035; overall); similarly, trends towards better total and LDL cholesterol levels were observed with iGlarLixi versus iGlar. In patient subgroups achieving glycaemic targets, all lipid variables except for HDL cholesterol improved with iGlarLixi but not with iGlar. In summary, patients with type 2 diabetes uncontrolled on basal insulin showed improved fasting lipid profiles with iGlarLixi compared with iGlar, particularly when achieving glycaemic targets.
Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/therapeutic use , Insulin Glargine/therapeutic use , Peptides/therapeutic use , Blood Glucose/analysis , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/metabolism , Humans , Hypoglycemic Agents/administration & dosage , Insulin Glargine/administration & dosage , Lipids/blood , Peptides/administration & dosageABSTRACT
AIM: To conduct two exploratory analyses to compare indirectly the efficacy and safety of simultaneous administration of insulin glargine 100 U (iGlar) and the glucagon-like peptide-1 receptor agonist (GLP-1RA) lixisenatide (Lixi) as a single-pen, titratable, fixed-ratio combination (iGlarLixi [LixiLan trials]) vs sequential administration of iGlar + Lixi (GetGoal Duo trials) in people with type 2 diabetes (T2D). MATERIALS AND METHODS: Propensity-score matching based on baseline covariates was used to compare simultaneous iGlarLixi vs sequential combination of iGlar + Lixi with the addition of Lixi in patients who did not reach the glycated haemoglobin (HbA1c) goal of <53 mmol/mol (<7%) after short-term use of iGlar alone (LixiLan-O vs GetGoal Duo-1 comparison) and vs sequential addition of Lixi in uncontrolled patients after long-term use of iGlar alone (LixiLan-L vs GetGoal Duo-2 comparison). RESULTS: In both analyses, compared with sequential iGlar + Lixi, iGlarLixi led to significantly greater HbA1c reductions with associated weight loss and significantly more patients reaching target HbA1c <53 mmol/mol despite lower insulin doses. Symptomatic hypoglycaemia rates were similar, despite greater HbA1c reductions with iGlarLixi. Lower rates of gastrointestinal adverse events were observed with iGlarLixi, probably as a result of the more gradual titration of Lixi with iGlarLixi. CONCLUSIONS: Indirect propensity-score-matched exploratory comparisons suggest that early treatment with a simultaneous, titratable, fixed-ratio combination of basal insulin and a GLP-1RA (iGlarLixi) may be more effective and possess better gastrointestinal tolerability than a sequential approach of adding a GLP-1RA in patients with uncontrolled T2D initiating or intensifying basal insulin therapy.
Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/administration & dosage , Insulin Glargine/administration & dosage , Peptides/administration & dosage , Adult , Aged , Clinical Trials, Phase III as Topic , Comparative Effectiveness Research , Diabetes Mellitus, Type 2/blood , Drug Administration Schedule , Drug Combinations , Drug Therapy, Combination , Female , Gastrointestinal Diseases/chemically induced , Glycated Hemoglobin/drug effects , Humans , Hypoglycemia/chemically induced , Male , Middle Aged , Propensity Score , Randomized Controlled Trials as Topic , Treatment OutcomeABSTRACT
The present post hoc analysis of two 30-week clinical trials compared efficacy and hypoglycaemia outcomes at early study visits with iGlarLixi (insulin glargine U100 [iGlar] and lixisenatide) vs iGlar alone in patients with type 2 diabetes (T2D) uncontrolled on oral antidiabetic drugs (OADs; LixiLan-O trial) or basal insulin (LixiLan-L trial). Time to control, defined as days to achieve glycated haemoglobin (HbA1c) <53 mmol/mol (<7%) or fasting plasma glucose (FPG) ≤7.2 mmol/L, was estimated using the Kaplan-Meier method. In the LixiLan-O and LixiLan-L trials, 60% and 46% of patients, respectively, reached HbA1c <53 mmol/mol (<7%) with iGlarLixi at 12 weeks, vs 45% and 24%, respectively, with iGlar. In the LixiLan-O trial, the median time to target HbA1c was approximately half with iGlarLixi vs iGlar (85.0 vs 166.0 days; P < .0001). In the LixiLan-L trial, the median time to target HbA1c was 153.0 days with iGlarLixi, while target HbA1c was never reached by 50% of patients with iGlar (P < .0001). Time-to-target FPG and hypoglycaemia outcomes were similar between treatments. In T2D uncontrolled on OADs or basal insulin, iGlarLixi resulted in glycaemic control in more patients than did iGlar at early treatment time points.
Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/administration & dosage , Insulin Glargine/administration & dosage , Peptides/administration & dosage , Adult , Blood Glucose/drug effects , Diabetes Mellitus, Type 2/blood , Drug Combinations , Fasting/blood , Female , Glycated Hemoglobin/drug effects , Humans , Hypoglycemia/chemically induced , Kaplan-Meier Estimate , Male , Middle Aged , Time Factors , Treatment OutcomeABSTRACT
BACKGROUND: The LNCaP cell line was originally isolated from the lymph node of a patient with metastatic prostate cancer. Many cell lines have been derived from LNCaP by selective pressures to study different aspects of prostate cancer progression. When injected subcutaneously into male athymic nude mice, LNCaP and its derivatives rarely metastasize. METHODS: Here, we describe the characteristics of a new LNCaP derivative, JHU-LNCaP-SM, which was generated by long term passage in normal cell culture conditions. RESULTS: Short tandem repeat (STR) analysis and genomic sequencing verified JHU-LNCaP-SM derivation from parental LNCaP cells. JHU-LNCaP-SM cells express the same mutated androgen receptor (AR) but unlike LNCaP, are no longer androgen dependent for growth. The cells demonstrate an attenuated androgen responsiveness in transcriptional assays and retain androgen sensitive expression of PSA, AR, and PSMA. Unlike parental LNCaP, JHU-LNCaP-SM cells quickly form subcutaneous tumors in male athymic nude mice, reliably metastasize to the lymph nodes and display a striking intra-tumoral and spreading hemorrhagic phenotype as tumor xenografts. CONCLUSIONS: The JHU-LNCaP-SM cell line is a new isolate of LNCaP, which facilitates practical, preclinical studies of spontaneous metastasis of prostate cancer through lymphatic tissues.
Subject(s)
Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Animals , Cell Line, Tumor , Humans , Male , Mice , Mice, Nude , Xenograft Model Antitumor Assays/methodsABSTRACT
BACKGROUND: Glycosylation of flavonoids is a promising approach to improve the pharmacokinetic properties and biological activities of flavonoids. Recently, many efforts such as enzymatic biocatalysis and the engineered Escherichia coli biotransformation have increased the production of flavonoid glucosides. However, the low yield of flavonoid glucosides can not meet the increasing demand for human medical and dietary needs. Saccharomyces cerevisiae is a generally regarded as safe (GRAS) organism that has several attractive characteristics as a metabolic engineering platform for the production of flavonoid glucosides. However, endogenous glucosidases of S. cerevisiae as a whole-cell biocatalyst reversibly hydrolyse the glucosidic bond and hinder the biosynthesis of the desired products. In this study, a model flavonoid, scutellarein, was used to exploit how to enhance the production of flavonoid glucosides in the engineered S. cerevisiae. RESULTS: To produce flavonoid glucosides, three flavonoid glucosyltransferases (SbGTs) from Scutellaria baicalensis Georgi were successfully expressed in E. coli, and their biochemical characterizations were identified. In addition, to synthesize the flavonoid glucosides in whole-cell S. cerevisiae, SbGT34 was selected for constructing the engineering yeast. Three glucosidase genes (EXG1, SPR1, YIR007W) were knocked out using homologous integration, and the EXG1 gene was determined to be the decisive gene of S. cerevisiae in the process of hydrolysing flavonoid glucosides. To further enhance the potential glycosylation activity of S. cerevisiae, two genes encoding phosphoglucomutase and UTP-glucose-1-phosphate uridylyltransferase involved in the synthetic system of uridine diphosphate glucose were over-expressed in S. cerevisiae. Consequently, approximately 4.8 g (1.2 g/L) of scutellarein 7-O-glucoside (S7G) was produced in 4 L of medium after 54 h of incubation in a 10-L fermenter while being supplied with ~3.5 g of scutellarein. CONCLUSIONS: The engineered yeast harbouring SbGT with a deletion of glucosidases produced more flavonoid glucosides than strains without a deletion of glucosidases. This platform without glucosidase activity could be used to modify a wide range of valued plant secondary metabolites and to explore of their biological functions using whole-cell S. cerevisiae as a biocatalyst.
Subject(s)
Flavonoids/biosynthesis , Glucosidases/genetics , Glucosides/biosynthesis , Saccharomyces cerevisiae/metabolism , Apigenin/metabolism , Culture Media , Fermentation , Gene Deletion , Glucose/metabolism , Glucuronates/metabolism , Hydrogen-Ion Concentration , Metabolic Engineering , Recombinant Proteins/biosynthesis , Recombinant Proteins/genetics , Saccharomyces cerevisiae/enzymology , Saccharomyces cerevisiae/geneticsABSTRACT
BACKGROUND: Glutathione (GSH), a pivotal non-protein thiol, can be biosynthesized through three pathways in different organisms: (1) two consecutive enzymatic reactions catalyzed by γ-glutamylcysteine synthetase (Gsh1 or GshA) and glutathione synthetase (Gsh2 or GshB); (2) a bifunctional γ-glutamylcysteine synthetase/glutathione synthetase (GshF); (3) an alternative condensation of γ-glutamyl phosphate synthesized by γ-glutamyl kinase (Pro1 or ProB) with cysteine to form γ-glutamylcysteine which was further conjugated to glycine by glutathione synthetase. The Gsh1 and Gsh2 of conventional GSH biosynthetic pathway or the bifunctional GshF reported previously have been independently modulated for GSH production. This study developed a novel three-pathway combination method to improve GSH production in Saccharomyces cerevisiae. RESULTS: A bifunctional enzyme GshF of Actinobacillus pleuropneumoniae was functionally expressed in S. cerevisiae and Pro1 in proline biosynthetic pathway was exploited for improving GSH yield. Moreover, two fusion proteins Gsh2-Gsh1 and Pro1-GshB were constructed to increase the two-step coupling efficiency of GSH synthesis by mimicking the native domain fusion of GshF. The engineered strain W303-1b/FGP with three biosynthetic pathways presented the highest GSH concentration (216.50 mg/L) and GSH production of W303-1b/FGP was further improved by 61.37 % when amino acid precursors (5 mM glutamic acid, 5 mM cysteine and 5 mM glycine) were fed in shake flask cultures. In batch culture process, the recombinant strain W303-1b/FGP also kept high efficiency in GSH production and reached an intracellular GSH content of 2.27 % after 24-h fermentation. CONCLUSIONS: The engineered strains harbouring three GSH pathways displayed higher GSH producing capacity than those with individually modulated pathways. Three-pathway combinatorial biosynthesis of GSH promises more effective industrial production of GSH using S. cerevisiae.
Subject(s)
Glutathione/biosynthesis , Saccharomyces cerevisiae/metabolism , Actinobacillus pleuropneumoniae/genetics , Bioreactors , Metabolic Engineering , Metabolic Networks and Pathways , Organisms, Genetically Modified/metabolism , Recombinant Fusion Proteins/metabolism , Saccharomyces cerevisiae/enzymologyABSTRACT
Peptide cyclization, a pivotal approach to modifying linear precursors of proteins and pepticles, has been used to enhance their biological activities and serum stabilities. Recently, sortase A (SrtA) from Staphyloccus aureus becomes a promising new technology for efficiently incorporating site specific modifications into proteins, conjugating the cell surface and cyclizing the linear peptides. In this study, we constructed two recombinant expression systems, one with chitin binding domain and the other with six-histidine tag and chitin binding domain on the N-terminal of SrtA, separately. The results of enzymatic kinetics indicate that the two recombinant tags do not impair the transpeptidase activity of SrtA compared with the standard reaction reported under the same reaction condition. The two synthesized peptides with N-ternimal three glycines and C-terminal penta-amino acid motif, LPETG, were cyclized using immobilized and recycled SrtA. The SrtA-based cyclization promises to represent a simple method for easy and efficient enzymatic synthesis of large cyclic peptides.
Subject(s)
Aminoacyltransferases/metabolism , Bacterial Proteins/metabolism , Cysteine Endopeptidases/metabolism , Enzymes, Immobilized/metabolism , Peptides, Cyclic/biosynthesis , Peptides/metabolism , Cyclization , Kinetics , Staphylococcus aureus/enzymologyABSTRACT
BACKGROUND: Circulating tumor cells (CTCs) hold great promise as biomarkers and are a direct source of tumor cells through a simple blood draw. However, CTCs are rare and their detection requires sensitive and specific methods to overcome the overwhelming hematocyte population. Therefore, CTC detection remains technically challenging. METHODS: An assay was developed for detecting viable and tissue-specific CTCs using a tropism-enhanced and conditionally replicating reporter adenovirus (CTC-RV). Adenoviral replication was made prostate-specific by placing the E1A gene under the control of the probasin promoter and prostate-specific antigen enhancer (PSE-PBN). Viral tropism was expanded through capsid-displayed integrin targeting peptides. A secreted reporter, humanized Metridia Luciferase (hMLuc), was engineered for expression during the major late phase of viral replication. The assay involves red blood cell lysis, cell collection, viral infection, and subsequent quantification of reporter activity from cellular media. Assay and reporter stability, cell specificity and sensitivity were evaluated in cell dilution models in human blood. RESULTS: A conditionally replicating prostate-selective adenovirus reporter and CTC assay system were generated. The secreted reporter, MLuc, was found to be stable for at least 3 days under assay conditions. CTC detection, modeled by cell dilution in blood, was selective for androgen receptor positive prostate cancer (PCa) cells. Serial dilution demonstrated assay linearity and sensitivity to as few as three cells. Prostate cancer cell viability declined after several hours in anticoagulated blood at ambient temperatures. CONCLUSIONS: Conditionally replicative adenoviral vectors and secreted reporters offer a functional method to detect viable CTCs with cell specificity and high sensitivity.
Subject(s)
Biomarkers, Tumor/blood , Neoplastic Cells, Circulating/pathology , Prostate/pathology , Prostatic Neoplasms/diagnosis , Cell Line, Tumor , Genetic Vectors , Humans , Male , Neoplastic Cells, Circulating/metabolism , Promoter Regions, Genetic , Prostate/metabolism , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/pathology , Sensitivity and SpecificityABSTRACT
miR-21 is the most commonly over-expressed microRNA (miRNA) in cancer and a proven oncogene. Hsa-miR-21 is located on chromosome 17q23.2, immediately downstream of the vacuole membrane protein-1 (VMP1) gene, also known as TMEM49. VMP1 transcripts initiate â¼ 130 kb upstream of miR-21, are spliced, and polyadenylated only a few hundred base pairs upstream of the miR-21 hairpin. On the other hand, primary miR-21 transcripts (pri-miR-21) originate within the last introns of VMP1, but bypass VMP1 polyadenylation signals to include the miR-21 hairpin. Here, we report that VMP1 transcripts can also bypass these polyadenylation signals to include miR-21, thus providing a novel and independently regulated source of miR-21, termed VMP1-miR-21. Northern blotting, gene-specific RT-PCR, RNA pull-down and DNA branching assays support that VMP1-miR-21 is expressed at significant levels in a number of cancer cell lines and that it is processed by the Microprocessor complex to produce mature miR-21. VMP1 and pri-miR-21 are induced by common stimuli, such as phorbol-12-myristate-13-acetate (PMA) and androgens, but show differential responses to some stimuli such as epigenetic modifying agents. Collectively, these results indicate that miR-21 is a unique miRNA capable of being regulated by alternative polyadenylation and two independent gene promoters.
Subject(s)
Membrane Proteins/genetics , MicroRNAs/genetics , Polyadenylation , Cell Line, Tumor , Gene Expression Regulation , Humans , Membrane Proteins/metabolism , MicroRNAs/metabolism , RNA Precursors/metabolism , RNA, Messenger/metabolism , Ribonuclease III/metabolism , Transcription, GeneticABSTRACT
Three cyclotides were isolated from the whole plant of Viola yedoensis in this study. The two, vary peptide E and cycloviolacin Y5, were previously reported, and a novel cycloviolacin VY1 was characterized according to the interpretation of MS/MS fragmentation of peptides which were produced from the reduced and alkylated parent peptide with the digestion of Endo Lys-C, trypsin and chymotrypsin, separately. The stability of remarkable resistance to proteolytic degradation by trypsin and chymotrypsin, and that of thermal denaturation was confirmed again. Besides, the IC50 value of cycloviolacin VY1 against influenza A H1N1 virus was (2.27 +/- 0.20) microg x mL(-1). It is the first cyclotide reported with anti-influenza A H1N1 virus activity in vitro assay.
Subject(s)
Antiviral Agents/pharmacology , Cyclotides/pharmacology , Influenza A Virus, H1N1 Subtype/drug effects , Viola/chemistry , Antiviral Agents/isolation & purification , Tandem Mass SpectrometryABSTRACT
CONTEXT: People with clinically diagnosed type 2 diabetes (T2D) but positive anti-glutamic acid decarboxylase autoantibodies (GADA), referred to here as latent autoimmune diabetes in adults (LADA), may experience more rapid glycemic deterioration than those with T2D and may benefit from effective diabetes treatment with additional metabolic benefits. OBJECTIVE: Assess glycated hemoglobin (HbA1c) and body weight (BW) changes associated with tirzepatide in GADA-positive versus GADA-negative participants with clinical T2D diagnosis. DESIGN: Post hoc analyses based on pooled data from SURPASS 2-5, using mixed-model repeated measures from the efficacy analysis set, adjusting for study and baseline covariates including age, sex, baseline values, body mass index (BMI), and GADA status. SETTING: N/A. PATIENTS: N = 3791. INTERVENTION: Tirzepatide (5, 10, 15â mg). MAIN OUTCOME MEASURE(S): Change from baseline in HbA1c at Weeks 40 (SURPASS-2, -3, -5) and 42 (SURPASS-4)by GADA status. RESULTS: In participants with confirmed GADA status, 3671 (96.8%) were GADA-negative and 120 (3.2%) were GADA-positive (76 [63.3%] with low and 44 [36.7%] with high GADA levels). Baseline characteristics were similar between groups, except for slightly lower BMI in GADA-positive versus GADA-negative participants (mean [SD] BMI 32.2 [6.1] versus 33.6 [6.3] kg/m2). At Week 40/42, both groups achieved robust reductions in HbA1c (-2.11% versus -2.32%) and BW (9.2â kg versus -9.6â kg) (p < 0.001, both groups). HbA1c reductions were greater in GADA-negative participants (estimated difference [95% CI]: 0.21% [0.03, 0.39]; p = 0.024) and BW reductions did not differ between groups (0.38â kg [-0.99, 1.75]; p = 0.588). CONCLUSIONS: In this post hoc analysis, tirzepatide was associated with substantial reductions in HbA1c and BW irrespective of GADA status in adults diagnosed with T2D, suggesting that tirzepatide may improve glycemic control in individuals with LADA.
ABSTRACT
Plant serine carboxypeptidase-like acyltransferases (SCPL-AT) have similar structural characteristics and high homology compared to the serine carboxypeptidase. They can transfer the acyl from acyl glucose esters to many natural products, participate in the acylation modification of plant secondary metabolites, enrich the structural diversity of natural products, and improve the physicochemical properties such as water solubility and stability of compounds. This review summarizes the structural characteristics, catalytic mechanism, functional characterization, and biocatalytic applications of SCPL-AT from plants. This will help to promote the functional characterization of these acyltransferase genes and the biosynthesis of useful plant secondary metabolites by synthetic biotechnology.
Subject(s)
Acyltransferases , Carboxypeptidases , Plants/enzymology , Acylation , Acyltransferases/genetics , Acyltransferases/metabolism , Carboxypeptidases/genetics , Carboxypeptidases/metabolismABSTRACT
AIMS/INTRODUCTION: The prevalence and pathophysiological background of type 2 diabetes mellitus vary across ethnicities, and can affect treatment responses. Adding lixisenatide to basal insulin (BI) in type 2 diabetes mellitus patients has shown improvements in glycated hemoglobin (HbA1c) and postprandial glycemic (PPG) excursions, without increasing hypoglycemic events. We aim to compare the efficacy of lixisenatide in Asian and white patients inadequately controlled with basal insulin. MATERIALS AND METHODS: An individual-level pooled analysis of two multi-national phase III studies, GetGoal-L and GetGoal-L-C, was carried out to assess the efficacy of lixisenatide versus placebo as an add-on treatment to BI ± metformin in Asian and white patients with type 2 diabetes mellitus. Change in HbA1c, 2-h PPG and PPG excursion were analyzed, along with possible predictors of glycemic control. RESULTS: Pooled data showed that baseline characteristics were similar between Asian and white patients with the exception of bodyweight, body mass index and BI dose being higher in white patients. After 24 weeks, lixisenatide reduced HbA1c in both ethnic groups, with no statistically significant difference between the two groups (Asian patients least squares mean difference -0.49, 95% confidence interval -0.68 to - 0.30 and white patients least squares mean difference -0.45, 95% confidence interval -0.63 to - 0.26; P = 0.6287). Similarly, no significant difference was found in 2-h PPG reduction between both groups (least squares mean difference for Asian vs white patients: -3.37 vs -3.93; P = 0.3203). Treatment with lixisenatide contributed to HbA1c reduction of -0.56% after adjustment of baseline HbA1c level in Asian patients, and -0.41% in white patients. CONCLUSIONS: Adding lixisenatide to BI significantly reduced HbA1c and 2-h PPG levels in both Asian and white participants with type 2 diabetes mellitus. No differences in treatment effect were observed between the two populations.