Obesity-associated mouse adipose stem cell secretion of monocyte chemotactic protein-1.
Studies showed that monocyte chemotactic protein-1 (MCP-1) concentrations are increased in obesity. In our current study, we demonstrate that plasma MCP-1 level in leptin-deficient ob/ob mice is significantly higher than in lean mice. Furthermore, we determined that basal adipose tissue MCP-1 mRNA levels are significantly higher in ob/ob mice compared with lean mice. To determine the mechanisms underlying obesity-associated increases in plasma and adipose tissue MCP-1 levels, we determined adipose tissue cell type sources of MCP-1 production. Our data show that adipose tissue stem cells (CD34(+)), macrophages (F4/80(+)), and stromal vascular fraction (SVF) cells express significantly higher levels of MCP-1 compared with adipocytes under both basal and lipopolysaccharide (LPS)-stimulated conditions. Furthermore, basal and LPS-induced MCP-1 secretion levels were the same for both adipose F4/80(+) and CD34(+) cells, whereas adipose CD34(+) cells have twofold higher cell numbers (30% of total SVF cells) compared with F4/80(+) macrophages (15%). Our data also show that CD34(+) cells from visceral adipose tissue depots secrete significantly higher levels of MCP-1 ex vivo when compared with CD34(+) cells from subcutaneous adipose tissue depots. Taken together, our data suggest that adipose CD34(+) stem cells may play an important role in obesity-associated increases in plasma MCP-1 levels.
Zhou
Hui Ren
HR
Food Science and Human Nutrition Department, Michigan State University, East Lansing, MI 48824-1224, USA.
Kim
Eun-Kyoung
EK
Kim
Hyojung
H
Claycombe
Kate J
KJ
D017667:Adipocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D052436:Adipose Tissue, White / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D000818:Animals; D018952:Antigens, CD34 / Q000276:immunology; D018932:Chemokine CCL2 / Q000097:blood / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008820:Mice, Obese; D009765:Obesity / Q000097:blood / Q000276:immunology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*
D018952:Antigens, CD34; D018932:Chemokine CCL2; D012333:RNA, Messenger