title: Immunohistochemistry of LAMP-2 and adipophilin for phospholipidosis in liver and kidney in ketoconazole-treated mice.
abstract: Drug-induced phospholipidosis is an abnormal accumulation of phospholipids in the lysosomes following repeated administration of cationic amphiphilic drugs. Phospholipidosis is detected histopathologically as cytoplasmic vacuolation; however, it is difficult to distinguish from lipid accumulation since their morphological features are similar. In this study, we investigated the usefulness of immunohistochemistry for lysosome-associated membrane protein-2 (LAMP-2) and adipophilin, a membrane protein of cytosolic non-lysosomal lipid droplets, in the liver and kidneys of mice orally administered ketoconazole, an inducer of hepatic phospholipidosis. In 7-week-old mice administered ketoconazole (300 mg/kg/day) for 7 days, cytoplasmic vacuolation was histopathologically observed in centrilobular hepatocytes and proximal tubular epithelial cells under the fasted condition. The cytoplasmic vacuolation consisted of foamy vacuoles, which were revealed to be phospholipidosis-characteristic lamellar bodies by electron microscopy. Furthermore, lipid-like vacuoles were observed in the perilobular hepatocytes, and revealed to be lipid droplets by electron microscopy. In immunohistochemistry, the foamy vacuoles and lipid-like vacuoles were positive for LAMP-2 and adipophilin, respectively. These results indicate that immunohistochemistry for LAMP-2 and adipophilin could distinguish between phospholipidosis and lipid accumulation. Additionally, it could detect ketoconazole-induced phospholipidosis in the glycogen-rich livers of non-fasted mice. In conclusion, ketoconazole induced phospholipidosis in not only the liver but also the kidneys, and immunohistochemistry for LAMP-2 and adipophilin could be useful for the pathological evaluation of drug-induced phospholipidosis in mice.
authors.affiliation: Toxicology and Pharmacokinetics Laboratories, Pharmaceutical Research Laboratories, Toray Industries, Inc., 6-10-1, Tebiro, Kamakura, Kanagawa 248-8555, Japan.
authors.forename: Yoshiji
authors.initials: Y
authors.lastname: Asaoka
authors.forename: Yuko
authors.initials: Y
authors.lastname: Togashi
authors.forename: Naoko
authors.initials: N
authors.lastname: Imura
authors.forename: Takafumi
authors.initials: T
authors.lastname: Sai
authors.forename: Tomoya
authors.initials: T
authors.lastname: Miyoshi
authors.forename: Yohei
authors.initials: Y
authors.lastname: Miyamoto
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000935:Antifungal Agents / Q000008:administration & dosage / Q000633:toxicity*; D007150:Immunohistochemistry; D007654:Ketoconazole / Q000008:administration & dosage / Q000633:toxicity*; D007668:Kidney / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism; D008099:Liver / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism; D008111:Liver Function Tests; D052119:Lysosomal-Associated Membrane Protein 2 / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D046529:Microscopy, Electron, Transmission; D009929:Organ Size / Q000187:drug effects; D000070780:Perilipin-2; D010743:Phospholipids / Q000378:metabolism*; D014463:Ultrasonography
chemical_list: D000935:Antifungal Agents; D052119:Lysosomal-Associated Membrane Protein 2; D008565:Membrane Proteins; D000070780:Perilipin-2; D010743:Phospholipids; C000602983:Plin2 protein, mouse; D007654:Ketoconazole
keywords: Adipophilin; Immunohistochemistry; Ketoconazole; Kidney; LAMP-2; Liver; Mice; Phospholipidosis