Niemann-Pick disease type C (NPC) is a lysosomal storage disease characterized by abnormal accumulation of free cholesterol and glycolipids. Here, we established induced pluripotent stem cell (iPSC) lines from NPC patients. Hepatocyte-like cells (HLCs) and neural progenitors derived from the iPSC lines accumulated cholesterol and displayed impaired autophagy and ATP production. A molecular signature related to lipid metabolism was also impaired in the NPC-iPSC-derived HLCs. These findings indicate that iPSC-derived cells can phenocopy human NPC. We also newly found that 2-hydroxypropyl-γ-cyclodextrin (HPGCD) could reduce the cholesterol accumulation and restore the functional and molecular abnormalities in the NPC patient-derived cells, and do so more effectively than 2-hydroxypropyl-β-cyclodextrin treatment. In addition, NPC model mice showed an improved liver status and prolonged survival with HPGCDs. Thus, iPSC lines derived from patient cells are powerful tools to study cellular models of NPC, and HPGCD is a potential new drug candidate for future treatment of this disease. Stem Cells 2015;33:1075–1088

Niemann-Pick type C disease (NPC), an autosomal recessive lysosomal storage disorder, is an inherited disease characterized by the accumulation of intracellular unesterified cholesterol. A solubilizing agent of lipophilic compounds, 2-hydroxypropyl-β-cyclodextrin (HPBCD), is an attractive drug candidate against NPC disease. However, establishment of the optimum dosage of HPBCD remains to be determined. In this study, we evaluated the effective dosage of HPBCD in NPC model (Npc1(-/-)) mice, and determined serum HPBCD concentrations. Subcutaneous injection of 1000-4000 mg/kg HPBCD improved the lifespan of Npc1(-/-) mice. In addition, liver injury and cholesterol sequestration were significantly prevented by 4000 mg/kg HPBCD in Npc1(-/-) mice. Serum HPBCD concentrations, when treated at the effective dosages (1000-4000 mg/kg), were approximately 1200-2500 µg/mL at 0.5 h after subcutaneous injection, and blood HPBCD concentrations were immediately eliminated in Npc1(-/-) mice. Furthermore, we examined serum HPBCD concentrations when treated at 40000 mg (approximately 2500 mg/kg) in a patient with NPC. We observed that the effective concentration in the in vivo study using Npc1(-/-) mice was similar to that in the patient. In the patient, systemic clearance and the volume of distribution of HPBCD were in accordance with the glomerular filtration rate and extracellular fluid volume, respectively. These results could provide useful information for developing the optimal dosage regimen for HPBCD therapy when administered intravenously to NPC patients.

Acetaminophen (paracetamol, N-acetyl-p-aminophenol; APAP) is the most popular analgesic/antipyretic agent in the world. APAP has been regarded as a safer drug compared with non-steroidal anti-inflammatory drugs (NSAIDs) particularly in terms of lower risks of renal dysfunction, gastrointestinal injury, and asthma/bronchospasm induction, even in high-risk patients such as the elderly, children, and pregnant women. On the other hand, the recent increasing use of APAP has raised concerns about its toxicity. In this article, we review recent pharmacological and toxicological findings about APAP from basic, clinical, and epidemiological studies, including spontaneous drug adverse events reporting system, especially focusing on drug-induced asthma and pre-and post-natal closure of ductus arteriosus. Hepatotoxicity is the greatest fault of APAP and the most frequent cause of drug-induced acute liver failure in Western countries. However, its precise mechanism remains unclear and no effective cure beyond N-acetylcysteine has been developed. Recent animal and cellular studies have demonstrated that some cellular events, such as c-jun N-terminal kinase (JNK) pathway activation, endoplasmic reticulum (ER) stress, and mitochondrial oxidative stress may play important roles in the development of hepatitis. Herein, the molecular mechanisms of APAP hepatotoxicity are summarized. We also discuss the not-so-familiar “dark side” of APAP as an otherwise safe analgesic/antipyretic drug.

Niemann-Pick Type C disease (NPC) is an autosomal recessive lysosomal storage disorder characterized by progressive neurological deterioration. Previously, we reported that intravenous administration of 2-hydroxypropyl-beta-cyclodextrin (HPB-CD) in two patients with NPC had only partial and transient beneficial effects on neurological function. The most likely reason for HPB-CD not significantly improving the neurological deficits of NPC is its inability to cross the blood-brain barrier. Herein, we describe the effects of intrathecal HPB-CD in an eight-year-old patient with a perinatal onset of NPC, administered initially at a dose of 10 mg/kg every other week and increased up to 10 mg/kg twice a week. Clinically, the patient maintained residual neurological functions for two years, at which time nuclear magnetic resonance spectroscopy showed a decreased choline to creatine ratio and increased N-acetylaspartate to creatine ratio, and positron emission tomography revealed increased standardized uptake values. Total-tau in the cerebrospinal fluid (CSF) was also decreased after two years. No adverse effects were observed over the course of treatment. The CSF concentrations of HPB-CD during the distribution phase after the injections were comparable with those at which HPB-CD could normalize cellular cholesterol abnormality in vitro. Further studies are necessary to elucidate the mechanisms of action of HPB-CD in NPC, and to determine the optimal dose and intervals of HPB-CD injection. (C) 2014 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-SA license

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