title: Prevention of fasting-mediated bone marrow atrophy by leptin administration.
abstract: Leptin is an adipokine that regulates body weight. In the current study, we demonstrate that continuous injection of leptin prevents the lymphocyte reduction observed in fasted mice, especially the immature B cell populations in the bone marrow. Although leptin administration reduced apoptotic cells in the bone marrow of fasted mice, it did not prevent glucocorticoid-mediated apoptosis in vitro. Bone marrow atrophy has also been shown in the leptin receptor-deficient db/db mice. In order to investigate the mechanisms underlying these processes, we transplanted bone marrow cells from db/db or control (+m/+m) mice into C.B-17/lcr-scid/scid mice. We found that the spleen and bone marrow B cell populations were completely reconstituted when db/db and +m/+m cells were transplanted into scid mice. Our findings suggest that direct interactions between leptin and bone marrow cells are not essential for the development of B cells in a metabologically normal environment.
authors.affiliation: Department of Hematology and Immunology, Kanazawa Medical University, Ishikawa, Japan. fujita-y@kanazawa-med.ac.jp
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Fujita
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Yanagida
authors.forename: Tsuneyo
authors.initials: T
authors.lastname: Mimori
authors.forename: Zhe-Xiong
authors.initials: ZX
authors.lastname: Jin
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Sakai
authors.forename: Takafumi
authors.initials: T
authors.lastname: Kawanami
authors.forename: Toshioki
authors.initials: T
authors.lastname: Sawaki
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Masaki
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Fukushima
authors.forename: Toshiro
authors.initials: T
authors.lastname: Okazaki
authors.forename: Hisanori
authors.initials: H
authors.lastname: Umehara
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002452:Cell Count; D005215:Fasting / Q000502:physiology*; D005260:Female; D020738:Leptin / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D016513:Mice, SCID; D012313:RNA / Q000737:chemistry / Q000235:genetics; D054411:Receptors, Leptin / Q000172:deficiency / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D020738:Leptin; D054411:Receptors, Leptin; C515447:leptin receptor, mouse; D012313:RNA