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Methods in Enzymology 2024Expression and purification of membrane-bound proteins remains a challenge and limits enzymology efforts, contributing to a substantial knowledge gap in the biochemical...
Expression and purification of membrane-bound proteins remains a challenge and limits enzymology efforts, contributing to a substantial knowledge gap in the biochemical functions of many proteins found in nature. Accordingly, the study of bacterial UbiA terpene synthases (TSs) has been limited due to the experimental hurdles required to purify active enzymes for characterization in vitro. Previous work employed the use of microsomes or crude membrane fractions to test enzyme activity; however, these methods can be labor intensive, require access to an ultracentrifuge, or may not be suitable for all membrane-bound TSs. We detail here an alternative strategy for the in vivo expression and biochemical characterization of the membrane associated UbiA TSs by employing a precursor overproduction system in Escherichia coli.
Topics: Escherichia coli; Alkyl and Aryl Transferases; Bacterial Proteins; Recombinant Proteins
PubMed: 38942512
DOI: 10.1016/bs.mie.2024.02.001 -
Nutrients Jun 2024High-fat diets cause gut dysbiosis and promote triglyceride accumulation, obesity, gut permeability changes, inflammation, and insulin resistance. Both cocoa butter and...
BACKGROUND
High-fat diets cause gut dysbiosis and promote triglyceride accumulation, obesity, gut permeability changes, inflammation, and insulin resistance. Both cocoa butter and fish oil are considered to be a part of healthy diets. However, their differential effects on gut microbiome perturbations in mice fed high concentrations of these fats, in the absence of sucrose, remains to be elucidated. The aim of the study was to test whether the sucrose-free cocoa butter-based high-fat diet (C-HFD) feeding in mice leads to gut dysbiosis that associates with a pathologic phenotype marked by hepatic steatosis, low-grade inflammation, perturbed glucose homeostasis, and insulin resistance, compared with control mice fed the fish oil based high-fat diet (F-HFD).
RESULTS
C57BL/6 mice (5-6 mice/group) were fed two types of high fat diets (C-HFD and F-HFD) for 24 weeks. No significant difference was found in the liver weight or total body weight between the two groups. The 16S rRNA sequencing of gut bacterial samples displayed gut dysbiosis in C-HFD group, with differentially-altered microbial diversity or relative abundances. , and were highly abundant in C-HFD group, while the , (TM7), , and were more abundant in F-HFD group. Other taxa in C-HFD group included the (AF12), and An increased Firmicutes/Bacteroidetes (F/B) ratio in C-HFD group, compared with F-HFD group, indicated the gut dysbiosis. These gut bacterial changes in C-HFD group had predicted associations with fatty liver disease and with lipogenic, inflammatory, glucose metabolic, and insulin signaling pathways. Consistent with its microbiome shift, the C-HFD group showed hepatic inflammation and steatosis, high fasting blood glucose, insulin resistance, increased hepatic de novo lipogenesis (Acetyl CoA carboxylases 1 (), Fatty acid synthase (), Stearoyl-CoA desaturase-1 (), Elongation of long-chain fatty acids family member 6 (), Peroxisome proliferator-activated receptor-gamma () and cholesterol synthesis (β-(hydroxy β-methylglutaryl-CoA reductase (). Non-significant differences were observed regarding fatty acid uptake (Cluster of differentiation 36 (), Fatty acid binding protein-1 () and efflux (ATP-binding cassette G1 (), Microsomal TG transfer protein () in C-HFD group, compared with F-HFD group. The C-HFD group also displayed increased gene expression of inflammatory markers including Tumor necrosis factor alpha (), C-C motif chemokine ligand 2 (), and Interleukin-12 (), as well as a tendency for liver fibrosis.
CONCLUSION
These findings suggest that the sucrose-free C-HFD feeding in mice induces gut dysbiosis which associates with liver inflammation, steatosis, glucose intolerance and insulin resistance.
Topics: Animals; Dysbiosis; Gastrointestinal Microbiome; Insulin Resistance; Diet, High-Fat; Mice, Inbred C57BL; Male; Mice; Fatty Liver; Liver; Dietary Fats; Sucrose
PubMed: 38931284
DOI: 10.3390/nu16121929 -
Foods (Basel, Switzerland) Jun 2024Silicon included in a restructured meat (RM) matrix (Si-RM) as a functional ingredient has been demonstrated to be a potential bioactive antidiabetic compound. However,...
Silicon included in a restructured meat (RM) matrix (Si-RM) as a functional ingredient has been demonstrated to be a potential bioactive antidiabetic compound. However, the jejunal and hepatic molecular mechanisms by which Si-RM exerts its cholesterol-lowering effects remain unclear. Male Wistar rats fed an RM included in a high-saturated-fat high-cholesterol diet (HSFHCD) combined with a low dose of streptozotocin plus nicotinamide injection were used as late-stage type 2 diabetes mellitus (T2DM) model. Si-RM was included into the HSFHCD as a functional food. An early-stage TD2M group fed a high-saturated-fat diet (HSFD) was taken as reference. Si-RM inhibited the hepatic and intestinal microsomal triglyceride transfer protein (MTP) reducing the apoB-containing lipoprotein assembly and cholesterol absorption. Upregulation of liver X receptor (LXRα/β) by Si-RM turned in a higher low-density lipoprotein receptor (LDLr) and ATP-binding cassette transporters (ABCG5/8, ABCA1) promoting jejunal cholesterol efflux and transintestinal cholesterol excretion (TICE), and facilitating partially reverse cholesterol transport (RCT). Si-RM decreased the jejunal absorptive area and improved mucosal barrier integrity. Consequently, plasma triglycerides and cholesterol levels decreased, as well as the formation of atherogenic lipoprotein particles. Si-RM mitigated the dyslipidemia associated with late-stage T2DM by Improving cholesterol homeostasis. Silicon could be used as an effective nutritional approach in diabetic dyslipidemia management.
PubMed: 38928736
DOI: 10.3390/foods13121794 -
International Journal of Molecular... Jun 2024Gyrophoric acid (GA), a lichen secondary metabolite, has attracted more attention during the last years because of its potential biological effects. Until now, its...
Gyrophoric acid (GA), a lichen secondary metabolite, has attracted more attention during the last years because of its potential biological effects. Until now, its effect in vivo has not yet been demonstrated. The aim of our study was to evaluate the basic physicochemical and pharmacokinetic properties of GA, which are directly associated with its biological activities. The stability of the GA in various pH was assessed by conducting repeated UV-VIS spectral measurements. Microsomal stability in rat liver microsomes was performed using Ultra-Performance LC/MS. Binding to human serum albumin (HSA) was assessed using synchronous fluorescence spectra, and molecular docking analysis was used to reveal the binding site of GA to HSA. In the in vivo experiment, 24 Sprague-Dawley rats (Velaz, Únetice, Czech Republic) were used. The animals were divided as follows. The first group ( = 6) included healthy males as control intact rats (♂INT), and the second group ( = 6) included healthy females as controls (♀INT). Groups three and four (♂GA/ = 6 and ♀GA/ = 6) consisted of animals with daily administered GA (10 mg/kg body weight) in an ethanol-water solution per os for a one-month period. We found that GA remained stable under various pH and temperature conditions. It bonded to human serum albumin with the binding constant 1.788 × 10 dmmol to reach the target tissue via this mechanism. In vivo, GA did not influence body mass gain, food, or fluid intake during the experiment. No liver toxicity was observed. However, GA increased the rearing frequency in behavioral tests ( < 0.01) and center crossings in the elevated plus-maze ( < 0.01 and < 0.001, respectively). In addition, the time spent in the open arm was prolonged ( < 0.01 and < 0.001, respectively). Notably, GA was able to pass through the blood-brain barrier, indicating its ability to permeate into the brain and to stimulate neurogenesis in the hilus and subgranular zone of the hippocampus. These observations highlight the potential role of GA in influencing brain function and neurogenesis.
Topics: Animals; Rats; Male; Molecular Docking Simulation; Female; Rats, Sprague-Dawley; Humans; Microsomes, Liver; Hydrogen-Ion Concentration; Serum Albumin, Human; Protein Binding
PubMed: 38928485
DOI: 10.3390/ijms25126782 -
Biomedicines Jun 2024The evaluation of in vitro biological activity of several previously reported quinolinequinones () against 60 human cancer cell lines (NCI-60) used by the National...
The evaluation of in vitro biological activity of several previously reported quinolinequinones () against 60 human cancer cell lines (NCI-60) used by the National Cancer Institute's Developmental Therapeutics Program (DTP) contributed to our earlier research on possible anticancer and/or antibacterial agents. Of interest, NCI-60 screening revealed that two quinolinequinones ( and ) significantly reduced the proliferation of several cancer genotypes. Following the administration of a single dose and five additional doses, all quinolinequinones demonstrated a significant inhibitory effect on the growth of leukemia and other cancer cell lines. Hence, a series of subsequent in vitro biological assessments were performed to further understand the mechanistic impact of the compounds. In MTT assays, it was found that and exhibited higher efficacy against DU-145 cells (IC 4.18 µM and 4.17 µM, respectively) compared to MDA-MB-231 (IC 8.27 and 13.33 µM, respectively) and HCT-116 cells (IC 5.83 and 9.18 µM, respectively). Additionally, demonstrated greater activity in this context. Further investigations revealed that inhibited DU-145 cell growth and migration dose-dependently. Remarkably, arrest of the DU-145 cell cycle at G0/G1 phase and ROS elevation were observed. Pharmacokinetic (PK) studies revealed that has better PK parameters than with %F of 9.83 in rat. Considering the data obtained with human liver microsomal stability studies, should have a better PK profile in human subjects. In silico studies (molecular dynamics) with three kinases (CDK2, CDK4, and MAPK) leading to cell cycle arrest at G/G identified MAPK as a probable target for . Taken together, our results showed that could be a potential chemotherapeutic lead molecule for prostate cancer.
PubMed: 38927448
DOI: 10.3390/biomedicines12061241 -
Biomolecules May 2024Glutathione transferases (GSTs) are the primary catalysts protecting from reactive electrophile attack. In this review, the quantitative levels and distribution of... (Review)
Review
Glutathione transferases (GSTs) are the primary catalysts protecting from reactive electrophile attack. In this review, the quantitative levels and distribution of glutathione transferases in relation to physiological function are discussed. The catalytic properties (random sequential) tell us that these enzymes have evolved to intercept reactive intermediates. High concentrations of enzymes (up to several hundred micromolar) ensure efficient protection. Individual enzyme molecules, however, turn over only rarely (estimated as low as once daily). The protection of intracellular protein and DNA targets is linearly proportional to enzyme levels. Any lowering of enzyme concentration, or inhibition, would thus result in diminished protection. It is well established that GSTs also function as binding proteins, potentially resulting in enzyme inhibition. Here the relevance of ligand inhibition and catalytic mechanisms, such as negative co-operativity, is discussed. There is a lack of knowledge pertaining to relevant ligand levels in vivo, be they exogenous or endogenous (e.g., bile acids and bilirubin). The stoichiometry of active sites in GSTs is well established, cytosolic enzyme dimers have two sites. It is puzzling that a third of the site's reactivity is observed in trimeric microsomal glutathione transferases (MGSTs). From a physiological point of view, such sub-stoichiometric behavior would appear to be wasteful. Over the years, a substantial amount of detailed knowledge on the structure, distribution, and mechanism of purified GSTs has been gathered. We still lack knowledge on exact cell type distribution and levels in vivo however, especially in relation to ligand levels, which need to be determined. Such knowledge must be gathered in order to allow mathematical modeling to be employed in the future, to generate a holistic understanding of reactive intermediate protection.
Topics: Glutathione Transferase; Humans; Kinetics; Animals
PubMed: 38927045
DOI: 10.3390/biom14060641 -
Toxicology and Applied Pharmacology Jun 2024To elucidate the impact of CYP3A4 activity inhibition and genetic polymorphism on the metabolism of crizotinib. Enzymatic incubation systems for crizotinib were...
To elucidate the impact of CYP3A4 activity inhibition and genetic polymorphism on the metabolism of crizotinib. Enzymatic incubation systems for crizotinib were established, and Sprague-Dawley rats were utilized for in vivo experiments. Analytes were quantified using LC-MS/MS. Upon screening 122 drugs and natural compounds, proanthocyanidins emerged as inhibitor of crizotinib metabolism, exhibiting a relative inhibition rate of 93.7%. The IC values were 24.53 ± 0.32 μM in rat liver microsomes and 18.24 ± 0.12 μM in human liver microsomes. In vivo studies revealed that proanthocyanidins markedly affected the pharmacokinetic parameters of crizotinib. Co-administration led to a significant reduction in the AUC, C of PF-06260182 (the primary metabolite of crizotinib), and the urinary metabolic ratio. This interaction is attributed to the mixed-type inhibition of liver microsome activity by proanthocyanidins. CYP3A4, being the principal metabolic enzyme for crizotinib, has its genetic polymorphisms significantly influencing crizotinib's pharmacokinetics. Kinetic data showed that the relative metabolic rates of crizotinib across 26 CYP3A4 variants ranged from 13.14% (CYP3A4.12, 13) to 188.57% (CYP3A4.33) when compared to the wild-type CYP3A4.1. Additionally, the inhibitory effects of proanthocyanidins varied between CYP3A4.12 and CYP3A4.33, when compared to the wild type. Our findings indicate that proanthocyanidins coadministration and CYP3A4 genetic polymorphism can significantly influence crizotinib metabolism.
PubMed: 38925514
DOI: 10.1016/j.taap.2024.117016 -
Biomedicine & Pharmacotherapy =... Jun 2024GLP-1 receptor agonists are clinically utilized for type 2 diabetes and obesity. In vitro and in vivo preclinical studies were performed to assess the druggability of a...
BACKGROUND AND PURPOSE
GLP-1 receptor agonists are clinically utilized for type 2 diabetes and obesity. In vitro and in vivo preclinical studies were performed to assess the druggability of a novel small molecule GLP-1 receptor biased agonist SAL0112.
EXPERIMENTAL APPROACH
The HTRF assay, FLIPR assay, TR-FRET assay, and PathHunter assay were utilized for in vitro studies. Liver transporter tests were conducted using the HEK293-OATP1B1 and HEK293-OATP1B3 cell lines. In vitro stability assessments of various species and in vivo PK studies in rodents were performed. A model of type 2 diabetes and obesity induced by a high-energy diet in transgenic C57BL/6 mice expressing the human GLP-1 receptor gene was conducted.
PRINCIPAL RESULTS
SAL0112 demonstrated high potency and selectivity in activating the Gαs pathway of the GLP-1 receptor, with no observed desensitization. SAL0112 demonstrated greater stability in human and rat liver microsomes compared to Danuglipron. In vivo PK studies revealed higher absorption of SAL0112 in rats. SAL0112 displayed a significantly lower potential for DDI on liver transporters compared to Danuglipron. SAL0112 led to significant reductions in body weight (P<0.001), blood glucose levels in OGTT (P<0.001), HbA (P<0.05) and improved insulin resistance (P<0.01). Notably, it increased peripheral adipocyte density and resolved hepatic steatosis. The efficacy of SAL0112 was found to be comparable to that of Danuglipron and Liraglutide.
CONCLUSION
SAL0112 demonstrated potent and selective GLP-1 receptor biased agonism, effectively alleviating signs of type 2 diabetes in a mouse model. These promising findings pave the way for the advancement of SAL0112 into clinical trials.
PubMed: 38925019
DOI: 10.1016/j.biopha.2024.116965 -
Toxins Jun 2024Physiologically based pharmacokinetic (PBPK) models were utilized to investigate potential interactions between aflatoxin B1 (AFB1) and efavirenz (EFV), a non-nucleoside...
Physiologically based pharmacokinetic (PBPK) models were utilized to investigate potential interactions between aflatoxin B1 (AFB1) and efavirenz (EFV), a non-nucleoside reverse transcriptase inhibitor drug and inducer of several CYP enzymes, including CYP3A4. PBPK simulations were conducted in a North European Caucasian and Black South African population, considering different dosing scenarios. The simulations predicted the impact of EFV on AFB1 metabolism via CYP3A4 and CYP1A2. In vitro experiments using human liver microsomes (HLM) were performed to verify the PBPK predictions for both single- and multiple-dose exposures to EFV. Results showed no significant difference in the formation of AFB1 metabolites when combined with EFV (0.15 µM) compared to AFB1 alone. However, exposure to 5 µM of EFV, mimicking chronic exposure, resulted in increased CYP3A4 activity, affecting metabolite formation. While co-incubation with EFV reduced the formation of certain AFB1 metabolites, other outcomes varied and could not be fully attributed to CYP3A4 induction. Overall, this study provides evidence that EFV, and potentially other CYP1A2/CYP3A4 perpetrators, can impact AFB1 metabolism, leading to altered exposure to toxic metabolites. The results emphasize the importance of considering drug interactions when assessing the risks associated with mycotoxin exposure in individuals undergoing HIV therapy in a European and African context.
Topics: Aflatoxin B1; Humans; Benzoxazines; Alkynes; Cyclopropanes; Microsomes, Liver; Drug Interactions; Models, Biological; Reverse Transcriptase Inhibitors; Male; Cytochrome P-450 CYP3A; Adult; Female; Cytochrome P-450 CYP1A2; Middle Aged; Young Adult; White People
PubMed: 38922153
DOI: 10.3390/toxins16060259 -
Metabolites Jun 2024Cannabichromene (CBC) is a minor cannabinoid within the array of over 120 cannabinoids identified in the plant. While CBC does not comprise a significant portion of...
Cannabichromene (CBC) is a minor cannabinoid within the array of over 120 cannabinoids identified in the plant. While CBC does not comprise a significant portion of whole plant material, it is available to the public in a purified and highly concentrated form. As minor cannabinoids become more popular due to their potential therapeutic properties, it becomes crucial to elucidate their metabolism in humans. Therefore, the goal of this was study to identify the major CBC phase I-oxidized metabolite generated in vitro following incubation with human liver microsomes. The novel metabolite structure was identified as 2'-hydroxycannabicitran using gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy. Following the identification, in silico molecular modeling experiments were conducted and predicted 2'-hydroxycannabicitran to fit in the orthosteric site of both the CB and CB receptors. When tested in vitro utilizing a competitive binding assay, the metabolite did not show significant binding to either the CB or CB receptors. Further work necessitates the determination of potential activity of CBC and the here-identified phase I metabolite in other non-cannabinoid receptors.
PubMed: 38921465
DOI: 10.3390/metabo14060329