title: Ethanol increases osteoclastogenesis associated with the increased expression             of RANK, PU.1 and MITF in vitro and in vivo.
abstract: Ethanol has been known to induce osteopenia. However, the cellular and molecular mechanisms responsible for its effect have not been well characterized. This study investigated the effects of ethanol on bone metabolism and osteoclastogenesis using rats fed an ethanol-containing liquid diet (35% of calories from ethanol) for 3 weeks. Ethanol increased the activities of bone tartrate-resistant acid phosphatase (TRAP) and cathepsin K, without affecting the levels of serum osteocalcin or bone alkaline phosphatase activity. Histological analysis showed an increased number of osteoclasts in the proximal tibia, but no significant change in the number of osteoblasts. The mRNA levels of receptor for activation of NF-κB (RANK), c-fos, c-jun, TRAP and cathepsin K were significantly increased, although those of macrophage colony-stimulating factor and c-fms were unaltered. The mRNA and protein levels of PU.1 and microphthalmia-associated trascription factor (MITF) also increased. Further, the osteoclastic differentiation of bone marrow-derived macrophage/monocyte precursor cells (BMMs) in vitro was stimulated by ethanol. The increased osteoclastogenesis of BMMs was associated with increased levels of RANK, PU.1 and MITF expression, activated extracellular signal-regulated kinase (ERK), and reactive oxygen species (ROS). Higher lipid peroxide levels and lower glutathione levels were also observed in the serum of the ethanol-fed rats. These results suggested that ethanol promoted osteoclastogenesis by increasing RANK expression through increases in the production of ROS, activation of ERK and expression of PU.1 and MITF.
authors.affiliation: Department of Food Science and Nutrition, Nara Women's University,                     Kita-uoya Nishi-machi, Nara 630-8506, Japan.
authors.forename: Natsumi
authors.initials: N
authors.lastname: Iitsuka
authors.forename: Mamiko
authors.initials: M
authors.lastname: Hie
authors.forename: Atsuko
authors.initials: A
authors.lastname: Nakanishi
authors.forename: Ikuyo
authors.initials: I
authors.lastname: Tsukamoto
mesh_terms: D000135:Acid Phosphatase / Q000096:biosynthesis / Q000235:genetics; D000469:Alkaline Phosphatase / Q000096:biosynthesis / Q000378:metabolism; D000818:Animals; D001862:Bone Resorption / Q000378:metabolism*; D056657:Cathepsin K / Q000096:biosynthesis / Q000235:genetics; D002454:Cell Differentiation / Q000187:drug effects; D000431:Ethanol / Q000494:pharmacology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000096:biosynthesis; D005978:Glutathione / Q000096:biosynthesis; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics; D008054:Lipid Peroxides / Q000096:biosynthesis; D008264:Macrophages / Q000378:metabolism; D008297:Male; D051739:Microphthalmia-Associated Transcription Factor / Q000096:biosynthesis* / Q000235:genetics; D016328:NF-kappa B / Q000235:genetics; D015675:Osteocalcin / Q000097:blood; D010010:Osteoclasts / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000096:biosynthesis* / Q000235:genetics; D000071681:Tartrate-Resistant Acid Phosphatase; D015534:Trans-Activators / Q000096:biosynthesis* / Q000235:genetics; D000099232:Proto-Oncogene Protein Spi-1
chemical_list: D000135:Acid Phosphatase; D000469:Alkaline Phosphatase; D056657:Cathepsin K; D000431:Ethanol; D048049:Extracellular Signal-Regulated MAP Kinases; D005978:Glutathione; D007527:Isoenzymes; D048031:JNK Mitogen-Activated Protein Kinases; D008054:Lipid Peroxides; D051739:Microphthalmia-Associated Transcription Factor; D016328:NF-kappa B; D015675:Osteocalcin; D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D053246:Receptor Activator of Nuclear Factor-kappa B; D000071681:Tartrate-Resistant Acid Phosphatase; D015534:Trans-Activators; D000099232:Proto-Oncogene Protein Spi-1; C497236:Mitf protein, rat