Project description:Co-migration / spiking experiment to confirm the retention time of drug analogs detected in HNRC fecal samples with those in microbial cultures
Project description:Co-migration / spiking experiment to confirm the retention time of drug analogs detected in HNRC fecal samples with those in microbial cultures
Project description:The trillions of microorganisms in the human gastrointestinal tract are an underexplored aspect of pharmacology. Despite numerous examples of microbial effects on drug efficacy and toxicity, there is often an incomplete understanding of the underlying mechanisms. Here, we dissect the inactivation of the commonly prescribed cardiac glycoside, digoxin, by Eggerthella lenta. Whole genome transcriptional profiling, comparative genomics, and culture-based assays revealed a cytochrome-encoding operon up-regulated by digoxin, absent in non-metabolizing E. lenta strains, and predictive of the efficiency of digoxin inactivation by the human gut microbiome. Digoxin inactivation was further enhanced by microbial interactions and inhibited by arginine. Pharmacokinetic studies using gnotobiotic mice revealed that increasing dietary protein reduces the in vivo metabolism of digoxin by E. lenta, with significant changes to drug concentration in the urine and serum. These results emphasize the importance of viewing pharmacology from the perspective of both our human and microbial genomes. RNA-Seq analysis of Eggerthella lenta cultured with or without digoxin.
Project description:High-throughput IM-MS analysis of drug metabolism incubations prepared from the MicroSource Spectrum Discovery Collection using pooled human liver microsomes and S9 fraction
Project description:The trillions of microorganisms in the human gastrointestinal tract are an underexplored aspect of pharmacology. Despite numerous examples of microbial effects on drug efficacy and toxicity, there is often an incomplete understanding of the underlying mechanisms. Here, we dissect the inactivation of the commonly prescribed cardiac glycoside, digoxin, by Eggerthella lenta. Whole genome transcriptional profiling, comparative genomics, and culture-based assays revealed a cytochrome-encoding operon up-regulated by digoxin, absent in non-metabolizing E. lenta strains, and predictive of the efficiency of digoxin inactivation by the human gut microbiome. Digoxin inactivation was further enhanced by microbial interactions and inhibited by arginine. Pharmacokinetic studies using gnotobiotic mice revealed that increasing dietary protein reduces the in vivo metabolism of digoxin by E. lenta, with significant changes to drug concentration in the urine and serum. These results emphasize the importance of viewing pharmacology from the perspective of both our human and microbial genomes.
Project description:While microbiome and pregnancy are known to alter drug disposition, the interplay of the two physiological factors to impact expression and/or activity of drug processing genes (DPGs) has yet to be elucidated. This study aimed to investigate the effects of microbiome on host hepatic DPGs during pregnancy using conventional (CV) and germ-free (GF) mice. Four groups of female mice were used, namely CV non-pregnant (CVNP), GF non-pregnant (GFNP), CV pregnant (CVP), and GF pregnant (GFP) mice. Pregnant mice examined were on gestation day 15. Transcriptomic and targeted proteomics of hepatic DPGs were profiled using a multi-omics approach. Plasma bile acid and steroid hormone levels were quantified using LC-MS/MS. Cyp3a activities were measured by mouse liver microsome incubations. While the overall trend in pregnancy-induced changes in the expression or activity of hepatic DPGs in CV and GF mice was similar, significant differences in the magnitude of changes were observed. For certain genes, we noticed opposite effects of pregnancy on mRNA and protein expression of DPGs in both CV and GF mice. For instance, the mRNA levels of Cyp3a11, the murine homolog of human CYP3A4, were decreased by 1.7-fold and 3.3-fold by pregnancy in CV and GF mice, respectively. However, the protein levels of Cyp3a11 were increased similarly ~2-fold by pregnancy in both CV and GF mice. Yet, microsome incubations revealed a marked induction of Cyp3a activity by pregnancy that was >5-fold greater in CV mice than that in GF mice. Plasma bile acid and steroid hormone levels were also significantly altered by microbiome and pregnancy, respectively, which may contribute to the differential effects of pregnancy in CV and GF mice. This is the first study to show that microbiome can alter hepatic DPGs in pregnancy.