Adiponectin, a fat cell product, influences the earliest lymphocyte precursors in bone marrow cultures by activation of the cyclooxygenase-prostaglandin pathway in stromal cells.
Adiponectin, an adipocyte-derived hormone, is attracting considerable interest as a potential drug for diabetes and obesity. Originally cloned from human s.c. fat, the protein is also found in bone marrow fat cells and has an inhibitory effect on adipocyte differentiation. The aim of the present study is to explore possible influences on lymphohematopoiesis. Recombinant adiponectin strongly inhibited B lymphopoiesis in long-term bone marrow cultures, but only when stromal cells were present and only when cultures were initiated with the earliest category of lymphocyte precursors. Cyclooxygenase inhibitors abrogated the response of early lymphoid progenitors to adiponectin in stromal cell-containing cultures. Furthermore, PGE(2), a major product of cyclooxygenase-2 activity, had a direct inhibitory influence on purified hematopoietic cells, suggesting a possible mechanism of adiponectin action in culture. In contrast to lymphopoiesis, myelopoiesis was slightly enhanced in adiponectin-treated bone marrow cultures, and even when cultures were initiated with single lymphomyeloid progenitors. Finally, human B lymphopoiesis was also sensitive to adiponectin in stromal cell cocultures. These results suggest that adiponectin can negatively and selectively influence lymphopoiesis through induction of PG synthesis. They also indicate ways that adipocytes in bone marrow can contribute to regulation of blood cell formation.
Yokota
Takafumi
T
Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
Meka
C S Reddy
CS
Kouro
Taku
T
Medina
Kay L
KL
Igarashi
Hideya
H
Takahashi
Masahiko
M
Oritani
Kenji
K
Funahashi
Tohru
T
Tomiyama
Yoshiaki
Y
Matsuzawa
Yuji
Y
Kincade
Paul W
PW
D017667:Adipocytes / Q000502:physiology*; D052242:Adiponectin; D000818:Animals; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000502:physiology; D001854:Bone Marrow Cells / Q000201:enzymology / Q000378:metabolism*; D002460:Cell Line; D019070:Cell Lineage / Q000276:immunology / Q000502:physiology; D002478:Cells, Cultured; D018920:Coculture Techniques; D004789:Enzyme Activation / Q000276:immunology / Q000502:physiology; D006131:Growth Inhibitors / Q000494:pharmacology / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D016131:Lymphocyte Subsets / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D038041:Lymphopoiesis / Q000276:immunology / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D022423:Myeloid Cells / Q000166:cytology / Q000502:physiology; D038042:Myelopoiesis / Q000276:immunology / Q000502:physiology; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism* / Q000502:physiology; D011453:Prostaglandins / Q000502:physiology; D014176:Protein Biosynthesis; D011506:Proteins / Q000494:pharmacology / Q000502:physiology*; D015398:Signal Transduction / Q000276:immunology / Q000502:physiology*; D017154:Stromal Cells / Q000201:enzymology / Q000378:metabolism
D052242:Adiponectin; D006131:Growth Inhibitors; D036341:Intercellular Signaling Peptides and Proteins; D011453:Prostaglandins; D011506:Proteins; D011451:Prostaglandin-Endoperoxide Synthases