查看更多>>摘要：We examined the impact of gut inflammation on the expression of cytochrome P450 (P450) and other biotransformation genes in male mice using a dextran sulfate sodium (DSS)-induced colitis model.Several P450 isoforms,including CYP1A,CYP2B,CYP2C,and CYP3A,were downregulated,accompanied by decreases in microsomal metabolism of diclofenac and nifedipine,in the liver and small intestine.The impact of the colitis on in vivo clearance of oral drugs varied for four different drugs tested:a small decrease for nifedipine,a relatively large decrease for lovastatin,but no change for pravastatin,and a large decrease in the absorption of cyclosporine A.To further assess the scope of influence of gut inflammation on gene expression,we performed genome-wide expression analysis using RNA-seq,which showed down-regulation of many CYPs,non-CYP phase-Ⅰ enzymes,phase-Ⅱ enzymes and transporters,and up-regulation of many other members of these gene families,in both liver and intestine of adult C57BL/6 mice,by DSS-induced colitis.Overall,our results indicate that gut inflammation suppresses the expression of many P450s and other biotransformation genes in the intestine and liver,and alters the pharmacokinetics for some but not all drugs,potentially affecting therapeutic efficacy or causing adverse effects in a drug-specific fashion.
Tomas SmutnyJan DusekLucie HyrsovaJana Nekvindova...
136-152页
查看更多>>摘要：Pregnane X receptor (PXR) is the major regulator of xenobiotic metabolism.PXR itself is controlled by various signaling molecules including glucocorticoids.Moreover,negative feed-back regulation has been proposed at the transcriptional level.We examined the involvement of the 3'-untranslated region (3'-UTR) of NR1I2 mRNA and microRNAs in PXR-and glucocorticoid receptor (GR)-mediated regulation of NR1I2 gene expression.PXR ligands were found to significantly down-regulate NR1I2 mRNA expression in a set of 14 human hepatocyte cultures.Similarly,PXR was downregulated by PCN in the C57/BL6 mice liver.In mechanistic studies with the full-length 3'-UTR cloned into luciferase reporter or expression vectors,we showed that the 3'-UTR reduces PXR expression.From the miRNAs tested,miR-18a-5p inhibited both NR1I2 expression and CYP3A4 gene induction.Importantly,we observed significant upregulation of miR-18a-5p expression 6 h after treatment with the PXR ligand rifampicin,which indicates a putative mechanism underlying NR1I2 negative feed-back regulation in hepatic cells.Additionally,glucocorticoids upregulated NR1I2 expression not only through the promoter region but also via 3'-UTR regulation,which likely involves downregulation of miR-18a-5p.We conclude that miR-18a-5p is involved in the down-regulation of NR1I2 expression by its ligands and in the upregulation of NR1I2 mRNA expression by glucocorticoids in hepatic cells.
Christina Ferrucci-Da SilvaLe ZhanJianliang ShenBo Kong...
153-158页
查看更多>>摘要：Parenteral nutrition-associated liver disease (PNALD) is a liver dysfunction caused by various risk factors presented in patients receiving total parenteral nutrition (TPN).Omega-6 rich Intralipid（R） and omega-3 rich Omegaven（R） are two intravenous lipid emulsions used in TPN.TPN could affect the hepatic expression of genes in anti-oxidative stress,but it's unknown whether TPN affects genes in drug metabolism.In this study,either Intralipid（R）-or Omegaven（R）-based TPN was administered to mice and the expression of a cohort of genes involved in anti-oxidative stress or drug metabolism was analyzed,glutathione (GSH) levels were measured,and protein levels for two key drug metabolism genes were determined.Overall,the expression of most genes was downregulated by Intralipid（R）-based TPN (Gstpl,Gstml,3,6,Nqo1,Ho-1,Mt-1,Gclc,Gclm,Cyp2d9,2f2,2b10,and 3a11).Omegaven（R） showed similar results as Intralipid（R） except for preserving the expression of Gstml and Cyp3a11,and increasing Ho-1.Total GSH levels were decreased by lntralipid（R）,but increased by Omegaven（R）.CYP3A11 protein levels were increased by Omegaven（R）.In conclusion,TPN reduced the expression of many genes involved in anti-oxidative stress and drug metabolism in mice.However,Omegaven（R） preserved expression of Cyp3a11,suggesting another beneficial effect of Omegaven（R） in protecting liver functions.
查看更多>>摘要：MicroRNAs (miRNAs or miRs) are small noncoding RNAs derived from genome to control target gene expression.Recently we have developed a novel platform permitting high-yield production of bioengineered miRNA agents (BERA).This study is to produce and utilize novel fully-humanized BERA/miR-328-3p molecule (hBERA/miR-328) to delineate the role of miR-328-3p in controlling nutrient uptake essential for cell metabolism.We first demonstrated successful high-level expression of hBERA/miR-328 in bacteria and purification to high degree of homogeneity (＞98％).Biologic miR-328-3p prodrug was selectively processed to miR-328-3p to suppress the growth of highly-proliferative human osteosarcoma (OS) cells.Besides glucose transporter protein type 1,gene symbol solute carrier family 2 member l (GLUT1/SLC2A1),we identified and verified large neutral amino acid transporter 1,gene symbol solute carrier family 7 member 5 (LAT1/SLC7A5) as a direct target for miR-328-3p.While reduction of LAT1 protein levels by miR-328-3p did not alter homeostasis of amino acids within OS cells,suppression of GLUT1 led to a significantly lower glucose uptake and decline in intracellular levels of glucose and glycolytic metabolite lactate.Moreover,combination treatment with hBERA/miR-328 and cisplatin or doxorubicin exerted a strong synergism in the inhibition of OS cell proliferation.These findings support the utility of novel bioengineered RNA molecules and establish an important role of miR-328-3p in the control of nutrient transport and homeostasis behind cancer metabolism.
查看更多>>摘要：The prevalence of obesity-associated conditions raises new challenges in clinical medication.Although altered expression of drug-metabolizing enzymes (DMEs) has been shown in obesity,the impacts of obese levels (overweight,obesity,and severe obesity) on the expression of DMEs have not been elucidated.Especially,limited information is available on whether parental obese levels affect ontogenic expression of DMEs in children.Here,a high-fat diet (HFD) and three feeding durations were used to mimic different obese levels in C57BL/6 mice.The hepatic expression of five nuclear receptors (NRs) and nine DMEs was examined.In general,a trend of induced expression of NRs and DMEs (except for Cvp2c29 and 3a11) was observed in HFD groups compared to low-fat diet (LFD) groups.Differential effects of HFD on the hepatic expression of DMEs were found in adult mice at different obese levels.Family-based dietary style of an HFD altered the ontogenic expression of DMEs in the offspring older than 15 days.Furthermore,obese levels of parental mice affected the hepatic expression of DMEs in offspring.Overall,the results indicate that obese levels affected expression of the DMEs in adult individuals and that of their children.Drug dosage might need to be optimized based on the obese levels.
查看更多>>摘要：Organic anion transporter 3 (OAT3) plays a vital role in removing a broad variety of anionic drugs from kidney,thus avoiding their possible toxicity in the body.In the current study,we investigated the role of insulin-like growth factor 1 (IGF-1) in the regulation of OAT3.We showed that IGF-1 induced a dose-and time-dependent increase in OAT3 transport activity,which correlated well with an increase in OAT3 expression.The IGF-1-induced increase in OAT3 expression was blocked by protein kinase A (PKA) inhibitor H89.Moreover,IGF-1 induced an increase in OAT3 phosphorylation,which was also blocked by H89.These data suggest that the IGF-1 modulation of OAT3 occurred through PKA signaling pathway.To further confirm the involvement of PKA,we treated OAT3-expressing cells with PKA activator Bt2-cAMP,followed by examining OAT activity and phosphorylation.We showed that OAT3 activity and phosphorylation were much enhanced in Bt2-cAMP-treated cells as compared to that in control cells.Finally,linsitinib,an anticancer drug that blocks the IGF-1 receptor,abrogated IGF-1-stimulated OAT3 transport activity.In conclusion,our study demonstrated that IGF-1 regulates OAT3 expression and transport activity through PKA signaling pathway,possibly by phosphorylating the transporter.
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