Lucette Doessegger1, Georg Schmitt2, Barbara Lenz2, Holger Fischer2, Götz Schlotterbeck3, Elke-Astrid Atzpodien2, Hans Senn4, Laura Suter3, Miklos Csato2, Stefan Evers5, Thomas Singer2. 1. Safety Risk Management/Licensing and Early Development, Building 682, Office 235, F. Hoffmann-La Roche AG, CH-4070, Basel, Switzerland. 2. Non-Clinical Safety, F. Hoffmann-La Roche AG, Basel, Switzerland. 3. Fachhochschule Nordwestschweiz/Hochschule für Life Sciences, Institut für Chemie und Bioanalytik, Muttenz, Switzerland. 4. Discovery Technology, F. Hoffmann-La Roche AG, Basel, Switzerland. 5. Roche Glycart AG, Schlieren, Switzerland.
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. MATERIALS AND 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. DISCUSSION AND CONCLUSION: 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.
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. MATERIALS AND 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. DISCUSSION AND CONCLUSION: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: Hector C Keun; Timothy M D Ebbels; Henrik Antti; Mary E Bollard; Olaf Beckonert; Götz Schlotterbeck; Hans Senn; Urs Niederhauser; Elaine Holmes; John C Lindon; Jeremy K Nicholson Journal: Chem Res Toxicol Date: 2002-11 Impact factor: 3.739
Authors: Prue M Pereira-Fantini; Sean G Byars; James Pitt; Susan Lapthorne; Fiona Fouhy; Paul D Cotter; Julie E Bines Journal: Sci Rep Date: 2017-02-23 Impact factor: 4.379