![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
B Transcription Factor and Induces IL-6 and TNF
Expression in 3T3-L1 Adipocytes1
Department of Animal Sciences, Center for Comparative Medicine, Purdue University, West Lafayette, IN 47907-2054
2To whom correspondence should be addressed. E-mail: spurloc0{at}purdue.edu.
Fatty acids and their metabolites regulate gene expression and immunological pathways. Furthermore, obese individuals frequently have increased circulating fatty acid concentrations, and localized inflammation in adipose tissue may facilitate the systemic inflammation associated with the insulin resistance of obesity. Although palmitate induces inflammation (i.e., activates proinflammatory pathways) in myotubes, the effects of fatty acids on inflammatory processes in adipocytes have not been established. Therefore, we examined the potential for palmitate, laurate, and docosahexaenoic acid (DHA) to modulate inflammation in 3T3-L1 adipocytes. Palmitate, but not DHA or laurate, induced nuclear factor 
B (NF-B)-driven luciferase activity and interleukin-6 (IL-6) expression (P < 0.05). Inhibition of fatty acyl Co-A synthase (FACS) with triacsin C suppressed palmitate-induced NF-B activation (P < 0.05), but caused an additive increase in palmitate-induced IL-6 expression (P < 0.05). Disrupting mitogen-activated protein kinase/Erk kinase (MEK) and protein kinase C (PKC) activity with U0126 and Bisindolylmaleimide (Bis), respectively, suppressed palmitate-induced IL-6 expression (P < 0.05), but had no effect on NF-B reporter gene activity (P > 0.05). However, the phosphoinositide-3 kinase (PI3K) inhibitor, wortmannin, alone and additively with palmitate, activated the NF-B reporter gene and induced IL-6 expression (P < 0.05). Palmitate also induced the mRNA expression of tumor necrosis factor 
(TNF) (P < 0.05), but the increase in mRNA abundance was not reflected in a greater protein concentration in the media (P > 0.05). These data indicate that palmitate induces inflammation in adipocytes, and that this is not a generalized effect of all SFA. Furthermore, PI3K may act constitutively to suppress inflammation. Consequently, inhibition of this enzyme may promote and exacerbate the inflammation in adipose tissue that is associated with obesity and insulin resistance.
KEY WORDS: • NF-B • fatty acids • cytokines • adipocyte • inflammation
This article has been cited by other articles:
|
|
 |
|
  A. Kalyvas, C. Baskakis, V. Magrioti, V. Constantinou-Kokotou, D. Stephens, R. Lopez-Vales, J.-Q. Lu, V. W. Yong, E. A. Dennis, G. Kokotos, et al. Differing roles for members of the phospholipase A2 superfamily in experimental autoimmune encephalomyelitis Brain, May 1, 2009; 132(5): 1221 - 1235. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Kennedy, K. Martinez, C.-C. Chuang, K. LaPoint, and M. McIntosh Saturated Fatty Acid-Mediated Inflammation and Insulin Resistance in Adipose Tissue: Mechanisms of Action and Implications J. Nutr., January 1, 2009; 139(1): 1 - 4. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. P. H. Hommelberg, J. Plat, R. C. J. Langen, A. M. W. J. Schols, and R. P. Mensink Fatty acid-induced NF-{kappa}B activation and insulin resistance in skeletal muscle are chain length dependent Am J Physiol Endocrinol Metab, January 1, 2009; 296(1): E114 - E120. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M.-S. Gauthier, H. Miyoshi, S. C. Souza, J. M. Cacicedo, A. K. Saha, A. S. Greenberg, and N. B. Ruderman AMP-activated Protein Kinase Is Activated as a Consequence of Lipolysis in the Adipocyte: POTENTIAL MECHANISM AND PHYSIOLOGICAL RELEVANCE J. Biol. Chem., June 13, 2008; 283(24): 16514 - 16524. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Takahashi, S. Yamaguchi, T. Shimoyama, H. Seki, K. Miyokawa, H. Katsuta, T. Tanaka, K. Yoshimoto, H. Ohno, S. Nagamatsu, et al. JNK- and I{kappa}B-dependent pathways regulate MCP-1 but not adiponectin release from artificially hypertrophied 3T3-L1 adipocytes preloaded with palmitate in vitro Am J Physiol Endocrinol Metab, May 1, 2008; 294(5): E898 - E909. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. K. Gabler and M. E. Spurlock Integrating the immune system with the regulation of growth and efficiency J Anim Sci, April 1, 2008; 86(14_suppl): E64 - E74. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Frost and C. H. Lang Regulation of muscle growth by pathogen-associated molecules J Anim Sci, April 1, 2008; 86(14_suppl): E84 - E93. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. E. Spurlock and N. K. Gabler The Development of Porcine Models of Obesity and the Metabolic Syndrome J. Nutr., February 1, 2008; 138(2): 397 - 402. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Y. Han, S. Subramanian, C. K. Chan, M. Omer, T. Chiba, T. N. Wight, and A. Chait Adipocyte-Derived Serum Amyloid A3 and Hyaluronan Play a Role in Monocyte Recruitment and Adhesion Diabetes, September 1, 2007; 56(9): 2260 - 2273. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Muniyappa, M. Montagnani, K. K. Koh, and M. J. Quon Cardiovascular Actions of Insulin Endocr. Rev., August 1, 2007; 28(5): 463 - 491. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Moloney, S. Toomey, E. Noone, A. Nugent, B. Allan, C. E. Loscher, and H. M. Roche Antidiabetic Effects of cis-9, trans-11-Conjugated Linoleic Acid May Be Mediated via Anti-Inflammatory Effects in White Adipose Tissue Diabetes, March 1, 2007; 56(3): 574 - 582. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Staiger, H. Staiger, C. Weigert, C. Haas, H.-U. Haring, and M. Kellerer Saturated, but Not Unsaturated, Fatty Acids Induce Apoptosis of Human Coronary Artery Endothelial Cells via Nuclear Factor-{kappa}B Activation Diabetes, November 1, 2006; 55(11): 3121 - 3126. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. D. Thakker, N. G. Frangogiannis, M. Bujak, P. Zymek, J. W. Gaubatz, A. K. Reddy, G. Taffet, L. H. Michael, M. L. Entman, and C. M. Ballantyne Effects of diet-induced obesity on inflammation and remodeling after myocardial infarction Am J Physiol Heart Circ Physiol, November 1, 2006; 291(5): H2504 - H2514. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Aeberli, L. Molinari, G. Spinas, R. Lehmann, D. l'Allemand, and M. B Zimmermann Dietary intakes of fat and antioxidant vitamins are predictors of subclinical inflammation in overweight Swiss children. Am. J. Clinical Nutrition, October 1, 2006; 84(4): 748 - 755. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. J. Senn Toll-like Receptor-2 Is Essential for the Development of Palmitate-induced Insulin Resistance in Myotubes J. Biol. Chem., September 15, 2006; 281(37): 26865 - 26875. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J.-a Kim, M. Montagnani, K. K. Koh, and M. J. Quon Reciprocal Relationships Between Insulin Resistance and Endothelial Dysfunction: Molecular and Pathophysiological Mechanisms Circulation, April 18, 2006; 113(15): 1888 - 1904. [Abstract] [Full Text] [PDF]
|
|
