4,495 research outputs found
Targeting Strategies for Multifunctional Nanoparticles in Cancer Imaging and Therapy
Nanomaterials offer new opportunities for cancer diagnosis and treatment. Multifunctional nanoparticles harboring various functions including targeting, imaging, therapy, and etc have been intensively studied aiming to overcome limitations associated with conventional cancer diagnosis and therapy. Of various nanoparticles, magnetic iron oxide nanoparticles with superparamagnetic property have shown potential as multifunctional nanoparticles for clinical translation because they have been used asmagnetic resonance imaging (MRI) constrast agents in clinic and their features could be easily tailored by including targeting moieties, fluorescence dyes, or therapeutic agents. This review summarizes targeting strategies for construction of multifunctional nanoparticles including magnetic nanoparticles-based theranostic systems, and the various surface engineering strategies of nanoparticles for in vivo applications
Optimization of Mass Spectrometry Imaging for Drug Metabolism and Distribution Studies in the Zebrafish Larvae Model: A Case Study with the Opioid Antagonist Naloxone
Zebrafish (ZF; Danio rerio) larvae have emerged as a promising in vivo model in drug
metabolism studies. Here, we set out to ready this model for integrated mass spectrometry imaging
(MSI) to comprehensively study the spatial distribution of drugs and their metabolites inside ZF
larvae. In our pilot study with the overall goal to improve MSI protocols for ZF larvae, we investigated
the metabolism of the opioid antagonist naloxone. We confirmed that the metabolic modification
of naloxone is in high accordance with metabolites detected in HepaRG cells, human biosamples,
and other in vivo models. In particular, all three major human metabolites were detected at high
abundance in the ZF larvae model. Next, the in vivo distribution of naloxone was investigated
in three body sections of ZF larvae using LC-HRMS/MS showing that the opioid antagonist is
mainly present in the head and body sections, as suspected from published human pharmacological
data. Having optimized sample preparation procedures for MSI (i.e., embedding layer composition,
cryosectioning, and matrix composition and spraying), we were able to record MS images of naloxone
and its metabolites in ZF larvae, providing highly informative distributional images. In conclusion,
we demonstrate that all major ADMET (absorption, distribution, metabolism, excretion, and toxicity)
parameters, as part of in vivo pharmacokinetic studies, can be assessed in a simple and cost-effective
ZF larvae model. Our established protocols for ZF larvae using naloxone are broadly applicable,
particularly for MSI sample preparation, to various types of compounds, and they will help to predict
and understand human metabolism and pharmacokinetics
Drug Administration Routes Impact the Metabolism of a Synthetic Cannabinoid in the Zebrafish Larvae Model
Zebrafish (Danio rerio) larvae have gained attention as a valid model to study in vivo drug
metabolism and to predict human metabolism. The microinjection of compounds, oligonucleotides,
or pathogens into zebrafish embryos at an early developmental stage is a well-established
technique. Here, we investigated the metabolism of zebrafish larvae after microinjection
of methyl 2-(1-(5-fluoropentyl)-1H-pyrrolo[2,3-b]pyridine-3-carboxamido)-3,3-dimethylbutanoate
(70N-5F-ADB) as a representative of recently introduced synthetic cannabinoids. Results were
compared to human urine data and data from the in vitro HepaRG model and the metabolic
pathway of 70N-5F-ADB were reconstructed. Out of 27 metabolites detected in human urine samples,
19 and 15 metabolites were present in zebrafish larvae and HepaRG cells, respectively. The route of
administration to zebrafish larvae had a major impact and we found a high number of metabolites
when 70N-5F-ADB was microinjected into the caudal vein, heart ventricle, or hindbrain. We further
studied the spatial distribution of the parent compound and its metabolites by mass spectrometry
imaging (MSI) of treated zebrafish larvae to demonstrate the discrepancy in metabolite profiles
among larvae exposed through different administration routes. In conclusion, zebrafish larvae
represent a superb model for studying drug metabolism, and when combined with MSI, the optimal
administration route can be determined based on in vivo drug distribution
Large-scale preparation of active caspase-3 in E. coli by designing its thrombin-activatable precursors
<p>Abstract</p> <p>Background</p> <p>Caspase-3, a principal apoptotic effector that cleaves the majority of cellular substrates, is an important medicinal target for the treatment of cancers and neurodegenerative diseases. Large amounts of the protein are required for drug discovery research. However, previous efforts to express the full-length caspase-3 gene in <it>E. coli </it>have been unsuccessful.</p> <p>Results</p> <p>Overproducers of thrombin-activatable full-length caspase-3 precursors were prepared by engineering the auto-activation sites of caspase-3 precursor into a sequence susceptible to thrombin hydrolysis. The engineered precursors were highly expressed as soluble proteins in <it>E. coli </it>and easily purified by affinity chromatography, to levels of 10–15 mg from 1 L of <it>E. coli </it>culture, and readily activated by thrombin digestion. Kinetic evaluation disclosed that thrombin digestion enhanced catalytic activity (<it>k</it><sub>cat</sub>/<it>K</it><sub><it>M</it></sub>) of the precursor proteins by two orders of magnitude.</p> <p>Conclusion</p> <p>A novel method for a large-scale preparation of active caspase-3 was developed by a strategic engineering to lack auto-activation during expression with amino acid sequences susceptible to thrombin, facilitating high-level expression in <it>E. coli</it>. The precursor protein was easily purified and activated through specific cleavage at the engineered sites by thrombin, generating active caspase-3 in high yields.</p
Induction of Liver Size Reduction in Zebrafish Larvae by the Emerging Synthetic Cannabinoid 4F-MDMB-BINACA and Its Impact on Drug Metabolism
Zebrafish (ZF; Danio rerio) larvae have become a popular in vivo model in drug metabolism
studies. Here, we investigated the metabolism of methyl 2-[1-(4-fluorobutyl)-1H-indazole-3-carboxamido]-
3,3-dimethylbutanoate (4F-MDMB-BINACA) in ZF larvae after direct administration of the cannabinoid
via microinjection, and we visualized the spatial distributions of the parent compound and its
metabolites by mass spectrometry imaging (MSI). Furthermore, using genetically modified ZF larvae,
the role of cannabinoid receptor type 1 (CB1) and type 2 (CB2) on drug metabolism was studied.
Receptor-deficient ZF mutant larvae were created using morpholino oligonucleotides (MOs), and
CB2-deficiency had a critical impact on liver development of ZF larva, leading to a significant
reduction of liver size. A similar phenotype was observed when treating wild-type ZF larvae with
4F-MDMB-BINACA. Thus, we reasoned that the cannabinoid-induced impaired liver development
might also influence its metabolic function. Studying the metabolism of two synthetic cannabinoids,
4F-MDMB-BINACA and methyl 2-(1-(5-fluoropentyl)-1H-pyrrolo[2,3-b]pyridine-3-carboxamido)-3,3-
dimethylbutanoate (70N-5F-ADB), revealed important insights into the in vivo metabolism of these
compounds and the role of cannabinoid receptor binding
Isolation and functional characterization of CE1 binding proteins
<p>Abstract</p> <p>Background</p> <p>Abscisic acid (ABA) is a plant hormone that controls seed germination, protective responses to various abiotic stresses and seed maturation. The ABA-dependent processes entail changes in gene expression. Numerous genes are regulated by ABA, and promoter analyses of the genes revealed that <it>cis</it>-elements sharing the ACGTGGC consensus sequence are ubiquitous among ABA-regulated gene promoters. The importance of the core sequence, which is generally known as ABA response element (ABRE), has been demonstrated by various experiments, and its cognate transcription factors known as ABFs/AREBs have been identified. Although necessary, ABRE alone is not sufficient, and another <it>cis</it>-element known as "coupling element (CE)" is required for full range ABA-regulation of gene expression. Several CEs are known. However, despite their importance, the cognate transcription factors mediating ABA response via CEs have not been reported to date. Here, we report the isolation of transcription factors that bind one of the coupling elements, CE1.</p> <p>Results</p> <p>To isolate CE1 binding proteins, we carried out yeast one-hybrid screens. Reporter genes containing a trimer of the CE1 element were prepared and introduced into a yeast strain. The yeast was transformed with library DNA that represents RNA isolated from ABA-treated Arabidopsis seedlings. From the screen of 3.6 million yeast transformants, we isolated 78 positive clones. Analysis of the clones revealed that a group of AP2/ERF domain proteins binds the CE1 element. We investigated their expression patterns and analyzed their overexpression lines to investigate the <it>in vivo </it>functions of the CE element binding factors (CEBFs). Here, we show that one of the CEBFs, AtERF13, confers ABA hypersensitivity in Arabidopsis, whereas two other CEBFs enhance sugar sensitivity.</p> <p>Conclusions</p> <p>Our results indicate that a group of AP2/ERF superfamily proteins interacts with CE1. Several CEBFs are known to mediate defense or abiotic stress response, but the physiological functions of other CEBFs remain to be determined. Our <it>in vivo </it>functional analysis of several CEBFs suggests that they are likely to be involved in ABA and/or sugar response. Together with previous results reported by others, our current data raise an interesting possibility that the coupling element CE1 may function not only as an ABRE but also as an element mediating biotic and abiotic stress responses.</p
Recognition of the microbiota by Nod2 contributes to the oral adjuvant activity of cholera toxin through the induction of interleukin-1β
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152023/1/imm13105_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152023/2/imm13105.pd
Investigation of Cation Exchange Behaviors of FA\u3csub\u3ex\u3c/sub\u3eMA\u3csub\u3e1-x\u3c/sub\u3ePBl\u3csub\u3e3\u3c/sub\u3e Films Using Dynamic Spin Coating
In this study, we fabricated and characterized uniform multi-cation perovskite FAxMA1−xPbI3 films. We used the dynamic spin-coating method to control the cation ratio of the film by gradually increasing the FA+, which replaced the MA+ in the films. When the FA+ concentration was lower than xFA ~0.415 in the films, the stability of the multi-cation perovskite improved. Above this concentration, the film exhibited δ-phase FAPbI3 in the FAxMA1−xPbI3 films. The formation of δ-phase FAPbI3 disturbed the homogeneity of the photoluminescence spatial distribution and suppressed the absorption spectral bandwidth with the increasing bandgap. The precise control of the cation ratio of multi-cation perovskite films is necessary to optimize the energy-harvesting performance
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