Xiaochao Ma, PhD

Assistant Professor
Ph.D., Shanghai Institute of Meteria Medica, Chinese Academy of Sciences, 2003
Postdoctoral Fellow, National Institutes of Health, 2008

Research Focus

Drug-drug interactions, Drug-induced liver injury, Toxicometabolomics

Dr. Ma's research focuses on the role of xenobiotic nuclear receptors in drug metabolism and metabolism-mediated liver injury. Pregnane X receptor (PXR; NR1I2) is one of the most important xenobiotic nuclear receptors regulating a large network of genes including those encoding metabolic enzymes and transporters. Recent advances in mouse models, including Pxr-null, PXR-humanized, and PXR/CYP3A4 double transgenic mice, provide ideal tools for evaluating the functions of human PXR and CYP3A4 in vivo. The laboratory utilizes these genetically engineered mouse models to investigate the mechanisms of drug-induced liver injury. In addition, we are interested in identifying small molecule biomarkers of drug-induced liver injury using an LC-MS-based metabolomic approach. Specific responding biomarkers will be used for elucidating the mechanisms of drug-induced liver injury.

Selected Publications

Li F, Lu J, Ma X.  Metabolomic screening and identification of bioactivation pathways of ritonavir.  Chem. Res. Toxicol. 2011, Oct 31. [Epub ahead of print]

Li F, Lu J, Ma X.  CPY3A4-mediated lopinavir bioactivation and its inhibition by ritonavir.  Drug. Metab. Dispos. 2011 Sep 27. [Epub ahead of print]

Li F, Miao Y, Zhang L, Neuenswander AS, Justin D, and Ma X.  Metabolomic analysis reveals novel isoniazid metabolites and hydrazones in human urine.  Drug Metab. Pharmacokinet. 2011 August 16. [Epub ahead of print]

Li F, Lu J, Ma X.  Profiling the reactive metabolites of xenobiotics using metabolomic technologies. Chem Res Toxicol. 2011; 24(5):744-51.

Li F, Lu J, Wang L, Ma X. CYP3A-mediated generation of aldehyde and hydrazine in atazanavir metabolism. Drug Metab Dispos. 2011; 39(3):394-401.

Wang L, Li F, Lu J, Li G, Li D, Zhong XB, Guo GL, Ma X. The Chinese herbal medicine Sophora flavescens activates pregnane X receptor. Drug Metab Dispos. 2010; 38(12):2226-31.

Niu S, Li F, Tan DX, Zhang L, Idle JR, Gonzalez FJ, Ma X. Analysis of N1-acetyl-N2-formyl-5-methoxykynuramine/N1-acetyl-5-methoxy-kynuramine formation from melatonin in mice. J Pineal Res. 2010; 49(2):106-14.

Li F, Wang L, Guo GL, Ma X. Metabolism-mediated drug interactions associated with ritonavir-boosted tipranavir in mice. Drug Metab Dispos. 2010; 38(5):871-8.

Guettier JM, Gautam D, Scarselli M, Ruiz de Azua I, Li JH, Rosemond E, Ma X, Gonzalez FJ, Armbruster BN, Lu H, Roth BL, Wess J. A chemical-genetic approach to study G protein regulation of beta cell function in vivo. Proc Natl Acad Sci U S A. 2009; 106(45):19197-202.

Ma X, Cheung C, Krausz KW, Shah YM, Wang T, Idle JR, Gonzalez FJ. A double transgenic mouse model expressing human pregnane X receptor and cytochrome P450 3A4. Drug Metab Dispos. 2008; 36(12):2506-12.

Ma X, Idle JR, Gonzalez FJ. The pregnane X receptor: from bench to bedside. Expert Opin Drug Metab Toxicol. 2008; 4(7):895-908.

Ma X, Chen C, Krausz KW, Idle JR, Gonzalez FJ. A metabolomic perspective of melatonin metabolism in the mouse. Endocrinology. 2008; 149(4):1869-79.

Ma X, Shah YM, Guo GL, Wang T, Krausz KW, Idle JR, Gonzalez FJ. Rifaximin is a gut-specific human pregnane X receptor activator. J Pharmacol Exp Ther. 2007; 322(1):391-8.

Ma X, Shah Y, Cheung C, Guo GL, Feigenbaum L, Krausz KW, Idle JR, Gonzalez FJ. The pregnane X receptor gene-humanized mouse: a model for investigating drug-drug interactions mediated by cytochromes P450 3A. Drug Metab Dispos. 2007; 35(2):194-200.