Kolapo Ajuwon
Research Program
The focus of the research in my laboratory is to determine factors that mediate the insulin resistant phenotype that occurs in the adipose tissue as it transitions from an insulin sensitive tissue to the insulin resistant state in obesity, and how nutritional manipulation can be used to prevent this transformation. Specifically, we are interested in characterizing endogenous factors that mediate adipose tissue inflammation. Current areas that are being investigated include the role of extracellular matrix factors, fatty acids and lipoproteins in the inflammatory process in adipose tissue. Obesity leads to extensive adipose tissue remodeling with significant alterations in the extracellular matrix (ECM) architecture. Accompanying this process is the increase in the levels of certain matrix degrading proteins such as matrix metalloproteinase (MMP) 2, 3 and 12 and extracellular proteins such as collagen I, III, VI, and biglycan. We are currently investigating the interaction of these ECM proteins with the adipocyte to characterize their role in obesity-induced inflammation. Interestingly, adipose tissue remodeling in obesity is suppressed by certain polyunsaturated fatty acids, but the mechanisms involved are unclear. Therefore, one major area of our research is to define the mechanisms that govern the anti-inflammatory actions of polyunsaturated fatty acids in adipose tissue. We employ cell biology, molecular biology techniques and whole animal approaches in the conduct of these investigations and our findings have practical relevance to solving obesity, type 2 diabetes and coronary artery disease problems in humans as well as optimizing animal growth.
Research Techniques
- Molecular biology techniques
- Cell biology techniques
- In vitro and in vivo nutrient metabolism
- Immunocytochemistry
Selected Publications
Jacobi SK, Gabler NK, Ajuwon KM, Davis JE, Spurlock ME. Adipocytes, myofibers, and cytokine biology: new horizons in the regulation of growth and body composition. J Anim Sci. 2006 84 Suppl: E140-9.
Ajuwon KM, Spurlock ME. Palmitate activates NF-kB transcription factor and induces IL-6 and TNFa expression in 3T3-L1 adipocytes 2005. J Nutr. 2005 Aug;135(8):1841-6
Ajuwon KM, Spurlock ME. Adiponectin inhibits LPS-induced NF-kappaB activation and IL-6 production and increases PPARgamma2 expression in adipocytes. Am J Physiol Regul Integr Comp Physiol. 2005 288:R1220-5.
Jacobi SK, Ajuwon KM, Weber TE, Kuske JL, Dyer CJ, Spurlock ME. Cloning and expression of porcine adiponectin, and its relationship to adiposity, lipogenesis and the acute phase response. J Endocrinol. 2004 182:133-44.
Ajuwon KM, Spurlock ME. Direct regulation of lipolysis by interleukin-15 in primary pig adipocytes. Am J Physiol Regul Integr Comp Physiol. 2004 287:R608-11.
Wulster-Radcliffe MC, Ajuwon KM, Wang J, Christian JA, and Spurlock ME. Adiponectin differentially regulates cytokines in porcine macrophages. Biochem Biophys Res Commun. 2004 316:924-9.
Ajuwon KM, Jacobi SK, Kuske JL, Spurlock ME.Interleukin-6 and interleukin-15 are selectively regulated by lipopolysaccharide and interferon-gamma in primary pig adipocytes. Am J Physiol Regul Integr Comp Physiol. 2004 286:R547-53.
Ajuwon K.M., J.L. Kuske, D.B. Anderson, D.L. Hancock, K.L. Houseknecht, O. Adeola, and M.E. Spurlock. Chronic leptin administration increases serum NEFA in the pig and differentially regulates PPAR expression in adipose tissue. Journal Nutritional Biochemistry. 2003.14: 576-83.
Ajuwon K.M., J.L Kuske, D. Ragland, O. Adeola, D.L. Hancock, D.B. Anderson, and M.E. Spurlock. The regulation of IGF-1 by leptin in the pig is tissue specific and independent of changes in growth hormone. Journal Nutritional Biochemistry. 2003. 14: 522-30.
Abstracts and Scientific Presentations
Anti-Diabetic Effects of (+)-Z-Bisdehydrodoisynolic Acid in Female Obese Zucker Rats. W. Banz, A. Strader, K. Ajuwon, L. Ortiz, B. James, D.A Higginbotham, Y. Hou, C. Meyers. Experimental Biology. April 28-May 2, 2007.
Linoleic acid Regulates the Expression of Oxidized Low Density Lipoprotein Receptor (OLR1) in 3T3-L1 Adipocytes via ERK and JNK Pathways. K. M Ajuwon, Dru M. Franklin, W.J. Banz, and T.A Winters. Experimental Biology. April 28-May 2, 2007.
Upregulation of PTEN Gene Expression in Adipocytes by Oxidized Low Density Lipoprotein: Implication for Impairment of Insulin Signaling in Obesity. Kolapo Ajuwon, Dru M Franklin, Rumi Mochida. 67th Scientific Session, American Diabetes Association, June 22-26, 2007
Ajuwon, K.M., J. Kuske, O. Adeola, D. L. Hancock, D. B. Anderson, and M. E. Spurlock. 2002. Leptin reduces feed intake and increases serum fatty acid concentrations in growing pigs, but does not regulate acetyl Co-A carboxylase activity or PPARa expression in adipose tissue. J. Anim. Sci. Vol. 80, Suppl. 1/J. Dairy Sci. Vol. 85, Suppl. 1 Presented at the Joint ASAS-ADSA-CSAS meeting, July 21-25. Oral Presentation.
Ajuwon, K.M. and Michael E. Spurlock. 2004. Adiponectin Attenuates the Induction of IL-6 by Lipopolysaccharide in Primary Pig Adipocytes, and Induces the Expression of PPARg2. Presented at the 86th Annual Meeting of The Endocrine Society at New Orleans, June 16-19, 2004.
Barrett, B. L., Ajuwon, K.M, Joanne L. Kuske and Michael E. Spurlock. 2004. Regulation of Lipogenesis and Inhibitory G-protein Function in Primary Pig Adipocytes by Leptin. Presented at the 86th Annual Meeting of The Endocrine Society at New Orleans, June 16-19, 2004.