18 research outputs found
Mitogenome and Nuclear-encoded Fungicide-target Genes of Thecaphora frezii - Causal Agent of Peanut Smut
Background: Thecaphora frezii Carranza and Lindquist causes smut disease in peanut (Arachis hypogaea L.) resulting in up to 35% yield losses. Fungicides have shown ineffective in controlling the disease; whereas research on the molecular basis of that fungicide resistance has been hindered because of the lack of genetic information about T. frezii. The goal of this work was to provide molecular information about fungicide-target loci in T. frezii, including its mitochondrial genome (mitogenome) and critical nuclear-encoded genes.
Results: Here we report the complete annotated mitogenome of T. frezii, a 123,773 bp molecule containing the standard 14 genes that form part of mitochondrial complexes I, III, IV and V, 22 transfer RNAs, small and large subunits of ribosomal RNA, DNA polymerase, ribonuclease P, GII-reverse transcriptase/maturase, nine hypothetical open-reading frames and homing endonucleases (LAGLIDADG, GIY-YIG, HEG). In addition, we report the full-length cDNA sequence of T. frezii cytochrome b (cob) and cytochrome oxidase 1 (cox1) genes; as well as partial sequences of T. frezii succinate dehydrogenase (sdhb), ergosterol biosynthesis (Erg4), cytochrome P450 (cyp51), and beta tubulin (β-tubulin) genes, which are respective targets of strobilurins, quinone oxidation inhibitors, triazoles and beta-tubulin inhibitor fungicides commonly used in the peanut crop. Translation of cob and sdhb genes in this particular T. frezii isolate suggests potential resistance to strobilurin and carboxamide fungicides.
Conclusion: The mitogenome and nuclear-encoded gene sequences presented here provide the molecular tools to research T. frezii fungicide-target loci
Identification of Glycochenodeoxycholate 3-O-glucuronide and Glycodeoxycholate 3-O-glucuronide as Highly Sensitive and Specific OATP1B1 Biomarkers
The aim of this study was to investigate the sensitivity and specificity of endogenous glycochenodeoxycholate and glycodeoxycholate 3-O-glucuronides (GCDCA-3G and GDCA-3G) as substrates for organic anion transporting polypeptide 1B1 (OATP1B1) in humans. We measured fasting levels of plasma GCDCA-3G and GDCA-3G using liquid chromatography-tandem mass spectrometry in 356 healthy volunteers. The mean plasma levels of both compounds were similar to 50% lower in women than in men (P = 2.25 x 10(-18) and P = 4.73 x 10(-9)). In a microarray-based genome-wide association study, theSLCO1B1rs4149056 (c.521T>C, p.Val174Ala) variation showed the strongest association with the plasma GCDCA-3G (P = 3.09 x 10(-30)) and GDCA-3G (P = 1.60 x 10(-17)) concentrations. The mean plasma concentration of GCDCA-3G was 9.2-fold (P = 8.77 x 10(-31)) and that of GDCA-3G was 6.4-fold (P = 2.45x10(-13)) higher in individuals with theSLCO1B1c.521C/C genotype than in those with the c.521T/T genotype. No other variants showed independent genome-wide significant associations with GCDCA-3G or GDCA-3G. GCDCA-3G was highly efficacious in detecting theSLCO1B1c.521C/C genotype with an area under the receiver operating characteristic curve of 0.996 (P <0.0001). The sensitivity (98-99%) and specificity (100%) peaked at a cutoff value of 180 ng/mL for men and 90 ng/mL for women. In a haplotype-based analysis,SLCO1B1*5and*15were associated with reduced, andSLCO1B1*1B, *14, and *35with increased OATP1B1 function.In vitro, both GCDCA-3G and GDCA-3G showed at least 6 times higher uptake by OATP1B1 than OATP1B3 or OATP2B1. These data indicate that the hepatic uptake of GCDCA-3G and GDCA-3G is predominantly mediated by OATP1B1. GCDCA-3G, in particular, is a highly sensitive and specific OATP1B1 biomarker in humans.Peer reviewe
2017 White Paper on recent issues in bioanalysis: aren't BMV guidance/guidelines ‘Scientific’? : Part 1 – LCMS: small molecules, peptides and small molecule biomarkers
The 2017 11th Workshop on Recent Issues in Bioanalysis (11th WRIB) took place in Los Angeles/Universal City, California on 3–7 April 2017 with participation of close to 750 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, weeklong event – a full immersion week of bioanalysis, biomarkers and immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small and large molecule analysis involving LCMS, hybrid ligand binding assay (LBA)/LCMS and LBA approaches. This 2017 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2017 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 2) covers the recommendations for biotherapeutics, biomarkers and immunogenicity assays using hybrid LBA/LCMS and regulatory agencies’ inputs. Part 1 (LCMS for small molecules, peptides and small molecule biomarkers) and Part 3 (LBA: immunogenicity, biomarkers and pharmacokinetic assays) are published in Volume 9 of Bioanalysis, issues 22 and 24 (2017), respectively
A multiplex HRMS assay for quantifying selected human plasma bile acids as candidate OATP biomarkers
Mitogenome and Nuclear-encoded Fungicide-target Genes of Thecaphora frezii - Causal Agent of Peanut Smut
Background: Thecaphora frezii Carranza and Lindquist causes smut disease in peanut (Arachis hypogaea L.) resulting in up to 35% yield losses. Fungicides have shown ineffective in controlling the disease; whereas research on the molecular basis of that fungicide resistance has been hindered because of the lack of genetic information about T. frezii. The goal of this work was to provide molecular information about fungicide-target loci in T. frezii, including its mitochondrial genome (mitogenome) and critical nuclear-encoded genes.
Results: Here we report the complete annotated mitogenome of T. frezii, a 123,773 bp molecule containing the standard 14 genes that form part of mitochondrial complexes I, III, IV and V, 22 transfer RNAs, small and large subunits of ribosomal RNA, DNA polymerase, ribonuclease P, GII-reverse transcriptase/maturase, nine hypothetical open-reading frames and homing endonucleases (LAGLIDADG, GIY-YIG, HEG). In addition, we report the full-length cDNA sequence of T. frezii cytochrome b (cob) and cytochrome oxidase 1 (cox1) genes; as well as partial sequences of T. frezii succinate dehydrogenase (sdhb), ergosterol biosynthesis (Erg4), cytochrome P450 (cyp51), and beta tubulin (β-tubulin) genes, which are respective targets of strobilurins, quinone oxidation inhibitors, triazoles and beta-tubulin inhibitor fungicides commonly used in the peanut crop. Translation of cob and sdhb genes in this particular T. frezii isolate suggests potential resistance to strobilurin and carboxamide fungicides.
Conclusion: The mitogenome and nuclear-encoded gene sequences presented here provide the molecular tools to research T. frezii fungicide-target loci
Preclinical Development of an anti-5T4 Antibody–Drug Conjugate: Pharmacokinetics in Mice, Rats, and NHP and Tumor/Tissue Distribution in Mice
The
pharmacokinetics of an antibody (huA1)–drug (auristatin
microtubule disrupting MMAF) conjugate, targeting 5T4-expressing cells,
were characterized during the discovery and development phases in
female nu/nu mice and cynomolgus monkeys after a single dose and in
S-D rats and cynomolgus monkeys from multidose toxicity studies. Plasma/serum
samples were analyzed using an ELISA-based method for antibody and
conjugate (ADC) as well as for the released payload using an LC-MS/MS
method. In addition, the distribution of the Ab, ADC, and released
payload (cys-mcMMAF) was determined in a number of tissues (tumor,
lung, liver, kidney, and heart) in two tumor mouse models (H1975 and
MDA-MB-361-DYT2 models) using similar LBA and LC-MS/MS methods. Tissue
distribution studies revealed preferential tumor distribution of cys-mcMMAF
and its relative specificity to the 5T4 target containing tissue (tumor).
Single dose studies suggests lower CL values at the higher doses in
mice, although a linear relationship was seen in cynomolgus monkeys
at doses from 0.3 to 10 mg/kg with no evidence of TMDD. Evaluation
of DAR (drug–antibody ratio) in cynomolgus monkeys (at 3 mg/kg)
indicated that at least half of the payload was still on the ADC 1
to 2 weeks after IV dosing. After multiple doses, the huA1 and conjugate
data in rats and monkeys indicate that exposure (AUC) increases with
increasing dose in a linear fashion. Systemic exposure (as assessed
by <i>C</i><sub>max</sub> and AUC) of the released payload
increased with increasing dose, although exposure was very low and
its pharmacokinetics appeared to be formation rate limited. The incidence
of ADA was generally low in rats and monkeys. We will discuss cross
species comparison, relationships between the Ab, ADC, and released
payload exposure after multiple dosing, and insights into the distribution
of this ADC with a focus on experimental design as a way to address
or bypass apparent obstacles and its integration into predictive models