title: Increased levels of urinary phenylacetylglycine associated with mitochondrial toxicity in a model of drug-induced phospholipidosis.
abstract: BACKGROUND
  Phospholipidosis (PLD) is a lysosomal storage disorder induced by a class of cationic amphiphilic drugs. However, drug-induced PLD is reversible. Evidence of PLD from animal studies with some compounds has led to discontinuation of development. Regulatory authorities are likely to request additional studies when PLD is linked to toxicity.
  
  
  OBJECTIVE
  We conducted a trial to investigate urinary phenylacetylglycine (uPAG) as a biomarker for PLD.
  
  
  METHODS
  Five groups of 12 male Wistar rats were dosed once with vehicle, 300 mg/kg or 1500 mg/kg of compound A (known to induce PLD), or 300 mg/kg or 1000 mg/kg of compound B (similar structure, but does not induce PLD) to achieve similar plasma exposures. Following dosing, urine and blood samples underwent nuclear magnetic resonance (NMR), proteomic, and biochemical analyses. Necropsies were performed at 48 and 168 h, organ histopathology evaluated, and gene expression in liver analyzed by microarray. Electron microscopic examination of peripheral lymphocytes was performed.
  
  
  RESULTS
  For compound A, uPAG increased with dose, correlating with lamellar inclusion bodies formation in peripheral lymphocytes. NMR analysis showed decreased tricarboxylic acid cycle intermediates, inferring mitochondrial toxicity. Mitochondrial dysfunction was suggested by uPAG increase, resulting from a switch to anaerobic metabolism or disruption of the urea cycle.
  
  
  CONCLUSIONS
  uPAG shows utility as a noninvasive biomarker for mitochondrial toxicity associated with drug-induced PLD, providing a mechanistic hypothesis for toxicity associated with PLD likely resulting from combined direct and indirect mitochondrial toxicity via impairment of the proton motor force and alteration of fatty acid catabolism.
authors.affiliation: Safety Risk Management/Licensing and Early Development, Building 682, Office 235, F. Hoffmann-La Roche AG, CH-4070, Basel, Switzerland.
authors.forename: Lucette
authors.initials: L
authors.lastname: Doessegger
authors.affiliation: Non-Clinical Safety, F. Hoffmann-La Roche AG, Basel, Switzerland.
authors.forename: Georg
authors.initials: G
authors.lastname: Schmitt
authors.affiliation: Non-Clinical Safety, F. Hoffmann-La Roche AG, Basel, Switzerland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Lenz
authors.affiliation: Non-Clinical Safety, F. Hoffmann-La Roche AG, Basel, Switzerland.
authors.forename: Holger
authors.initials: H
authors.lastname: Fischer
authors.affiliation: Fachhochschule Nordwestschweiz/Hochschule für Life Sciences, Institut für Chemie und Bioanalytik, Muttenz, Switzerland.
authors.forename: Götz
authors.initials: G
authors.lastname: Schlotterbeck
authors.affiliation: Non-Clinical Safety, F. Hoffmann-La Roche AG, Basel, Switzerland.
authors.forename: Elke-Astrid
authors.initials: EA
authors.lastname: Atzpodien
authors.affiliation: Discovery Technology, F. Hoffmann-La Roche AG, Basel, Switzerland.
authors.forename: Hans
authors.initials: H
authors.lastname: Senn
authors.affiliation: Fachhochschule Nordwestschweiz/Hochschule für Life Sciences, Institut für Chemie und Bioanalytik, Muttenz, Switzerland.
authors.forename: Laura
authors.initials: L
authors.lastname: Suter
authors.affiliation: Non-Clinical Safety, F. Hoffmann-La Roche AG, Basel, Switzerland.
authors.forename: Miklos
authors.initials: M
authors.lastname: Csato
authors.affiliation: Roche Glycart AG, Schlieren, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Evers
authors.affiliation: Non-Clinical Safety, F. Hoffmann-La Roche AG, Basel, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Singer
keywords: biomarker; phospholipidosis; urinary phenylacetylglycine
references.citation: Arzneimittelforschung. 1970 Mar;20(3):417
references.pmid: 5467520
references.citation: Exp Mol Pathol. 1995 Feb;62(1):12-21
references.pmid: 7556587
references.citation: Mol Cell Proteomics. 2006 Nov;5(11):2092-101
references.pmid: 16893879
references.citation: Clin Pharmacol Ther. 2008 Feb;83(2):210-2
references.pmid: 18202685
references.citation: J Biol Chem. 1985 Jan 10;260(1):215-9
references.pmid: 3965448
references.citation: Chem Res Toxicol. 2003 Nov;16(11):1395-404
references.pmid: 14615964
references.citation: J Biol Chem. 1992 Sep 25;267(27):19147-54
references.pmid: 1382068
references.citation: Lab Invest. 1991 Apr;64(4):574-84
references.pmid: 2016860
references.citation: Arch Toxicol. 1984 Oct;55(4):229-32
references.pmid: 6517699
references.citation: Anal Chem. 2006 Jun 1;78(11):3551-61
references.pmid: 16737207
references.citation: J Pharmacol Toxicol Methods. 2008 Jul-Aug;58(1):41-9
references.pmid: 18606234
references.citation: Biochemistry. 1985 Nov 5;24(23):6515-20
references.pmid: 4084534
references.citation: Chem Res Toxicol. 2002 Nov;15(11):1380-6
references.pmid: 12437328
references.citation: Toxicology. 1981;20(1):1-33
references.pmid: 7022749
references.citation: Electrophoresis. 2010 Jul;31(14):2349-55
references.pmid: 20575107
references.citation: J Biol Chem. 1957 Nov;229(1):463-76
references.pmid: 13491597
references.citation: Biochem Pharmacol. 1978;27(8):1103-8
references.pmid: 358990
references.citation: Toxicol Pathol. 2007 Aug;35(5):728-34
references.pmid: 17763287
references.citation: J Lipid Res. 1980 Feb;21(2):202-14
references.pmid: 6246184
references.citation: Nat Rev Drug Discov. 2004 Aug;3(8):711-5
references.pmid: 15286737
references.citation: J Pharmacol Exp Ther. 1990 Dec;255(3):1371-6
references.pmid: 2124623
references.citation: Mol Cell Biochem. 1987 Aug;76(2):163-72
references.pmid: 2823097
references.citation: Xenobiotica. 1982 Jun;12(6):387-95
references.pmid: 6753356
references.citation: Pharmacol Rev. 1990 Dec;42(4):327-54
references.pmid: 2080227
references.citation: Biochem Pharmacol. 1997 May 15;53(10):1521-32
references.pmid: 9260880
references.citation: Biochem Pharmacol. 2003 Apr 1;65(7):1115-28
references.pmid: 12663047
references.citation: N Engl J Med. 1995 Oct 26;333(17):1118-27
references.pmid: 7565951
references.citation: Front Biol. 1979;48:49-130
references.pmid: 387466
references.citation: Biochem Pharmacol. 1984 May 15;33(10):1639-44
references.pmid: 6732837
references.citation: Proc R Soc Lond B Biol Sci. 1972 Jul 25;182(1066):25-35
references.pmid: 4403084
references.citation: J Biol Chem. 2002 Apr 5;277(14):12221-7
references.pmid: 11790774
references.citation: Biomarkers. 2000;5(6):410-23
references.pmid: 23898812
references.citation: Exp Toxicol Pathol. 2007 Oct;59(2):115-20
references.pmid: 17719757
references.citation: Arch Pathol Lab Med. 1997 Dec;121(12):1269-71
references.pmid: 9431317
references.citation: J Med Chem. 2012 Jan 12;55(1):126-39
references.pmid: 22122484
references.citation: Environ Health Perspect. 2004 Aug;112(12):1236-48
references.pmid: 15345370
references.citation: Proc Natl Acad Sci U S A. 1999 Mar 16;96(6):3160-4
references.pmid: 10077654
references.citation: Biomarkers. 2004 May-Jun;9(3):271-90
references.pmid: 15764292
references.citation: Lab Invest. 1976 Aug;35(2):116-23
references.pmid: 957602
references.citation: Pharmacogenomics. 2006 Oct;7(7):1055-75
references.pmid: 17054416
references.citation: Cell Biol Toxicol. 2003 Jun;19(3):161-76
references.pmid: 12945744
references.citation: Am J Clin Nutr. 2011 Feb;93(2):314-21
references.pmid: 21177801
references.citation: Pediatr Res. 1991 Feb;29(2):147-50
references.pmid: 2014149