Regulation of monocyte chemoattractant protein 1 (MCP-1) release by explants of human visceral adipose tissue.
BACKGROUND
Monocyte chemoattractant protein-1 (MCP-1) is a chemokine involved in monocyte recruitment during inflammation whose plasma level is elevated in obesity.


OBJECTIVE
The present studies were designed to examine the release of MCP-1 in primary culture by explants of visceral adipose tissue from morbidly obese women.


RESULTS
Most of the MCP-1 released by adipose tissue explants was derived from the nonfat cells in adipose tissue. The release of MCP-1 by adipose tissue explants was upregulated almost five-fold between 3 and 48 h of incubation. Approximately half of this upregulation was due to the release of endogenous tumor necrosis factor alpha (TNFalpha) and IL-1beta based on the ability of a combination of a soluble TNFalpha receptor (etanercept) and a blocking antibody against IL-1beta to reduce MCP-1 release. The release of MCP-1 over 48 h was unaffected by insulin or dexamethasone but significantly reduced by the combination of both agents. MCP-1 release was reduced by 60% in the presence of an inhibitor of the nuclear factor kappaB (NF-kappaB) pathway. There were no significant effects of inhibitors of p44/42 mitogen-activated protein kinase (ERK), Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38 MAPK) pathways on MCP-1 release. However, inhibition of MCP-1 release in the presence of inhibitors of both the p38 MAPK and NF-kappaB pathways was greater than that seen with only the NF-kappaB inhibitor.


CONCLUSIONS
The present data shows that MCP-1 formation is upregulated over a 48-h incubation of primary explants of visceral adipose tissue. Half of this upregulation is dependent upon endogenous TNFalpha and Il-1beta and involves the p38 MAPK and NF-kappaB pathways.
Fain
J N
JN
Department of Molecular Sciences, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA. jfain@utmem.edu
Madan
A K
AK
D050153:Abdominal Fat / Q000378:metabolism*; D017667:Adipocytes / Q000378:metabolism; D000328:Adult; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D018932:Chemokine CCL2 / Q000378:metabolism*; D015232:Dinoprostone / Q000378:metabolism; D000068800:Etanercept; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology; D007375:Interleukin-1 / Q000276:immunology / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D008875:Middle Aged; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D009765:Obesity / Q000378:metabolism / Q000503:physiopathology*; D018124:Receptors, Tumor Necrosis Factor; D015398:Signal Transduction / Q000502:physiology*; D017154:Stromal Cells / Q000378:metabolism; D013997:Time Factors; D046509:Tissue Culture Techniques; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology / Q000378:metabolism; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
D000911:Antibodies, Monoclonal; D018932:Chemokine CCL2; D007074:Immunoglobulin G; D007375:Interleukin-1; D016328:NF-kappa B; D018124:Receptors, Tumor Necrosis Factor; C439524:TNF protein, human; D014409:Tumor Necrosis Factor-alpha; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D015232:Dinoprostone; D000068800:Etanercept