Adiponectin binds to chemokines via the globular head and modulates interactions between chemokines and heparan sulfates.
OBJECTIVE
Adiponectin, a fat cell-derived protein, has been attracting considerable attention because of its antidiabetic and antiatherogenic activities. The aim of the present study is to identify molecules physiologically associating with adiponectin and to understand how the protein displays diverse biological activities.


METHODS
We used an expression cloning method combined with enzyme-linked immunosorbent assay to clone adiponectin-binding proteins from the MS-5 complementary DNA library.


RESULTS
We successfully isolated two chemokines, stromal cell-derived factor-1 (SDF-1) and CCF18, and verified that adiponectin bound to them via its globular head. Adiponectin bound with various chemokines in vitro, such as macrophage-inflammatory protein-1alpha (MIP-1alpha), RANTES, and monocyte chemoattractant protein-1 (MCP-1), suggesting that the protein had a feature commonly to bind to the chemokine family. The middle part of chemokines, dispensable for interacting with their receptors, was found to be important for the adiponectin binding. Although the interaction of adiponectin to SDF-1 affected neither the SDF-1-CXCR4 binding nor the SDF-1 signaling in Jurkat cells, adiponectin and heparin mutually interfered in their association to SDF-1 and MCP-1 in vitro, implying that their association might influence the distribution of adiponectin and SDF-1 in inflammatory sites. Indeed, both adiponectin and SDF-1 was positively immunostained in vascular walls in guts from acute graft-vs-host disease patients. In addition, peripheral blood of adiponectin-deficient mice contained more hematopoietic progenitors than that of wild-type mice.


CONCLUSIONS
Adiponectin may be involved in regulation of inflammation via binding to specific chemokines. Additionally, the interaction possibly enables adiponectin to gather and play its role in inflammatory sites.
Masaie
Hiroaki
H
Department of Hematology and Oncology, Osaka University Graduate School of Medicine, Osaka, Japan.
Oritani
Kenji
K
Yokota
Takafumi
T
Takahashi
Isao
I
Shirogane
Takahiro
T
Ujiie
Hidetoshi
H
Ichii
Michiko
M
Saitoh
Norimitsu
N
Maeda
Tetsuo
T
Tanigawa
Rie
R
Oka
Kazumasa
K
Hoshida
Yoshihiko
Y
Tomiyama
Yoshiaki
Y
Kanakura
Yuzuru
Y
D000208:Acute Disease; D052242:Adiponectin / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D018925:Chemokines / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D006086:Graft vs Host Disease / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D006367:HeLa Cells; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000473:pathology; D006497:Heparan Sulfate / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D007410:Intestinal Diseases / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000473:pathology; D019169:Jurkat Cells; D051379:Mice; D018345:Mice, Knockout; D011485:Protein Binding; D015398:Signal Transduction
D052242:Adiponectin; D018925:Chemokines; D006497:Heparan Sulfate