21 research outputs found
Gene Expression Profiling in the Pituitary Gland of Laying Period and Ceased Period Huoyan Geese
Huoyan goose is a Chinese local breed famous for its higher laying performance, but the problems of variety degeneration have emerged recently, especially a decrease in the number of eggs laid. In order to better understand the molecular mechanism that underlies egg laying in Huoyan geese, gene profiles in the pituitary gland of Huoyan geese taken during the laying period and ceased period were investigated using the suppression subtractive hybridization (SSH) method. Total RNA was extracted from pituitary glands of ceased period and laying period geese. The cDNA in the pituitary glands of ceased geese was subtracted from the cDNA in the pituitary glands of laying geese (forward subtraction); the reverse subtraction was also performed. After sequencing and annotation, a total of 30 and 24 up and down-regulated genes were obtained from the forward and reverse SSH libraries, respectively. These genes mostly related to biosynthetic process, cellular nitrogen compound metabolic process, transport, cell differentiation, cellular protein modification process, signal transduction, small molecule metabolic process. Furthermore, eleven genes were selected for further analyses by quantitative real-time PCR (qRT-PCR). The qRT-PCR results for the most part were consistent with the SSH results. Among these genes, Synaptotagmin-1 (SYT1) and Stathmin-2 (STMN2) were substantially over-expressed in laying period compared to ceased period. These results could serve as an important reference for elucidating the molecular mechanism of higher laying performance in Huoyan geese
Analysis of the Constituents in Rat Serum after Oral Administration of Fufang Zhenzhu Tiaozhi Capsule by UPLCâQâTOFâMS/MS
A rapid and sensitive UPLC/QâTOFâMS method has been established for analysis of the constituents in rat serum after oral administration of Fufang Zhenzhu Tiaozhi (FTZ) capsule, an effective compound prescription for treating hyperlipidemia in the clinic. The UPLC/MS information of samples was obtained first in FTZ preparation and FTZ-treated rat serum. Mass spectra were acquired in both negative and positive ion modes. Thirty-six constituents in rat serum after oral administration of FTZ were detected, including the alkaloids, ginsenosides, pentacyclic triterpenes, and their metabolites. These chemicals were identified based on the retention time and mass spectrometry data with those of authentic standards or comparison of the literatures reports. Twenty-seven prototype components originated from FTZ and nine were the metabolites of the FTZ constituents. These results shed light on the potential active constituents of the complex traditional Chinese medicinal formulas
CYP3A-Mediated Generation of Aldehyde and Hydrazine in Atazanavir MetabolismSâ
Atazanavir (ATV) is an antiretroviral drug of the protease inhibitor class. Multiple adverse effects of ATV have been reported in clinical practice, such as jaundice, nausea, abdominal pain, and headache. The exact mechanisms of ATV-related adverse effects are unknown. It is generally accepted that a predominant pathway of drug-induced toxicity is through the generation of reactive metabolites. Our current study was designed to explore reactive metabolites of ATV. We used a metabolomic approach to profile ATV metabolism in mice and human liver microsomes. We identified 5 known and 13 novel ATV metabolites. Three potential reactive metabolites were detected and characterized for the first time: one aromatic aldehyde, one α-hydroxyaldehyde, and one hydrazine. These potential reactive metabolites were primarily generated by CYP3A. Our results provide a clue for studies on ATV-related adverse effects from the aspect of metabolic activation. Further studies are suggested to illustrate the impact of these potential reactive metabolites on ATV-related adverse effects
Metabolism-Mediated Drug Interactions Associated with Ritonavir-Boosted Tipranavir in Mice
Tipranavir (TPV) is the first nonpeptidic protease inhibitor used for the treatment of drug-resistant HIV infection. Clinically, TPV is coadministered with ritonavir (RTV) to boost blood concentrations and increase therapeutic efficacy. The mechanism of metabolism-mediated drug interactions associated with RTV-boosted TPV is not fully understood. In the current study, TPV metabolism was investigated in mice using a metabolomic approach. TPV and its metabolites were found in the feces of mice but not in the urine. Principal component analysis of the feces metabolome uncovered eight TPV metabolites, including three monohydroxylated, three desaturated, one dealkylated, and one dihydroxylated. In vitro study using human liver microsomes recapitulated five TPV metabolites, all of which were suppressed by RTV. CYP3A4 was identified as the primary enzyme contributing to the formation of four TPV metabolites (metabolites II, IV, V, and VI), including an unusual dealkylated product arising from carbon-carbon bond cleavage. Multiple cytochromes P450 (2C19, 2D6, and 3A4) contributed to the formation of a monohydroxylated metabolite (metabolite III). In vivo, RTV cotreatment significantly inhibited eight TPV metabolic pathways. In summary, metabolomic analysis revealed two known and six novel TPV metabolites in mice, all of which were suppressed by RTV. The current study provides solid evidence that the RTV-mediated boosting of TPV is due to the modulation of P450-dependent metabolism
Saccharomyces cerevisiae cellular engineering for the production of FAME biodiesel
Abstract The unsustainable and widespread utilization of fossil fuels continues to drive the rapid depletion of global supplies. Biodiesel has emerged as one of the most promising alternatives to conventional diesel, leading to growing research interest in its production. Microbes can facilitate the de novo synthesis of a type of biodiesel in the form of fatty acid methyl esters (FAMEs). In this study, Saccharomyces cerevisiae metabolic activity was engineered to facilitate enhanced FAME production. Initially, free fatty acid concentrations were increased by deleting two acetyl-CoA synthetase genes (FAA1, FAA4) and an acyl-CoA oxidase gene (POX1). Intracellular S-adenosylmethionine (SAM) levels were then enhanced via the deletion of an adenosine kinase gene (ADO1) and the overexpression of a SAM synthetase gene (SAM2). Lastly, the S. cerevisiae strain overproducing free fatty acids and SAM were manipulated to express a plasmid encoding the Drosophila melanogaster Juvenile Hormone Acid O-Methyltransferase (DmJHAMT). Using this combination of engineering approaches, a FAME concentration of 5.79â±â0.56 mg/L was achieved using these cells in the context of shaking flask fermentation. To the best of our knowledge, this is the first detailed study of FAME production in S. cerevisiae. These results will provide a valuable basis for future efforts to engineer S. cerevisiae strains for highly efficient production of biodiesel
Binding Kinetics versus Affinities in BRD4 Inhibition
Bromodomains
(BRDs) are protein modules that selectively recognize
histones as a âreaderâ by binding to an acetylated lysine
substrate. The human BRD4 has emerged as a promising drug target for
a number of disease pathways, and several potent BRD inhibitors have
been discovered experimentally recently. However, the detailed inhibition
mechanism especially for the inhibitor binding kinetics is not clear.
Herein, by employing classical molecular dynamics (MD) and state-of-the-art
density functional QM/MM MD simulations, the dynamic characteristics
of ZA-loop in BRD4 are revealed. And then the correlation between
binding pocket size and ZA-loop motion is elucidated. Moreover, our
simulations found that the compound (â)-JQ1 could be accommodated
reasonably in thermodynamics whereas it is infeasible in binding kinetics
against BRD4. Its racemate (+)-JQ1 proved to be both thermodynamically
reasonable and kinetically achievable against BRD4, which could explain
the previous experimental results that (+)-JQ1 shows a high inhibitory
effect toward BRD4 (IC<sub>50</sub> is 77 nM) while (â)-JQ1
is inactive (>10 ÎŒM). Furthermore, the L92/L94/Y97 in the
ZA-loop
and Asn140 in the BC-loop are identified to be critical residues in
(+)-JQ1 binding/releasing kinetics. All these findings shed light
on further selective inhibitor design toward BRD family, by exploiting
the non-negligible ligand binding kinetics features and flexible ZA-loop
motions of BRD, instead of only the static ligandâprotein binding
affinity
HAPLN1 Affects Cell Viability and Promotes the Pro-Inflammatory Phenotype of Fibroblast-Like Synoviocytes
HAPLN1 maintains aggregation and the binding activity of extracellular matrix (ECM) molecules (such as hyaluronic acid and proteoglycan) to stabilize the macromolecular structure of the ECM. An increase in HAPLN1 expression is observed in a few types of musculoskeletal diseases including rheumatoid arthritis (RA); however, its functions are obscure. This study examined the role of HAPLN1 in determining the viability, proliferation, mobility, and pro-inflammatory phenotype of RA- fibroblast-like synoviocytes (RA-FLSs) by using small interfering RNA (siHAPLN1), over-expression vector (HAPLN1OE), and a recombinant HAPLN1 (rHAPLN1) protein. HAPLN1 was found to promote proliferation but inhibit RA-FLS migration. Metformin, an AMPK activator, was previously found by us to be able to inhibit FLS activation but promote HAPLN1 secretion. In this study, we confirmed the up-regulation of HAPLN1 in RA patients, and found the positive relationship between HAPLN1 expression and the AMPK level. Treatment with either si-HAPLN1 or HAPLN1OE down-regulated the expression of AMPK-É gene, although up-regulation of the level of p-AMPK-É was observed in RA-FLSs. si-HAPLN1 down-regulated the expression of proinflammatory factors like TNF-É, MMPs, and IL-6, while HAPLN1OE up-regulated their levels. qPCR assay indicated that the levels of TGF-ÎČ, ACAN, fibronectin, collagen II, and Ki-67 were down-regulated upon si-HAPLN1 treatment, while HAPLN1OE treatment led to up-regulation of ACAN and Ki-67 and down-regulation of cyclin-D1. Proteomics of si-HAPLN1, rHAPLN1, and mRNA-Seq analysis of rHAPLN1 confirmed the functions of HAPLN1 in the activation of inflammation, proliferation, cell adhesion, and strengthening of ECM functions. Our results for the first time demonstrate the function of HAPLN1 in promoting the proliferation and pro-inflammatory phenotype of RA-FLSs, thereby contributing to RA pathogenesis. Future in-depth studies are required for better understanding the role of HAPLN1 in RA
Efficient CRISPRâCas9 mediated multiplex genome editing in yeasts
Abstract Background The thermotolerant methylotrophic yeast Ogataea polymorpha has been regarded as an important organism for basic research and biotechnological applications. It is generally recognized as an efficient and safe cell factory in fermentative productions of chemicals, biofuels and other bio-products. However, it is difficult to genetically engineer for the deficiency of an efficient and versatile genome editing technology. Results In this study, we developed a CRISPRâCas9-assisted multiplex genome editing (CMGE) approach including multiplex genes knock-outs, multi-locus (ML) and multi-copy (MC) integration methods in yeasts. Based on CMGE, various genome modifications, including gene deletion, integration, and precise point mutation, were performed in O. polymorpha. Using the CMGE-ML integration method, three genes TAL from Herpetosiphon aurantiacus, 4CL from Arabidopsis thaliana and STS from Vitis vinifera of resveratrol biosynthetic pathway were simultaneously integrated at three different loci, firstly achieving the biosynthesis of resveratrol in O. polymorpha. Using the CMGE-MC method,ââŒâ10 copies of the fusion expression cassette P ScTEF1 -TAL-P ScTPI1 -4CL-P ScTEF2 -STS were integrated into the genome. Resveratrol production was increasedâ~â20 fold compared to the one copy integrant and reached 97.23â±â4.84 mg/L. Moreover, the biosynthesis of human serum albumin and cadaverine were achieved in O. polymorpha using CMGE-MC to integrate genes HSA and cadA, respectively. In addition, the CMGE-MC method was successfully developed in Saccharomyces cerevisiae. Conclusions An efficient and versatile multiplex genome editing method was developed in yeasts. The method would provide an efficient toolkit for genetic engineering and synthetic biology researches of O. polymorpha and other yeast species
Additional file 1 of Saccharomyces cerevisiae cellular engineering for the production of FAME biodiesel
Supplementary Material