Department of Pathology & Laboratory Medicine
Laura A. Woollett, Ph.D.
Iowa State University, Biochemistry, 1987
Cholesterol is required at all stages of life. It is an integral
part of membranes and is used for hormone synthesis and bile acid synthesis.
During the fetal and neonatal periods, the requirement for sterol is greater
than that of the adult due to the rapid growth rate. Our laboratory
is interested in understanding the role of exogenous and endogenous cholesterol
during different stages of growth. Our projects include:
1) Determination of the sources of sterol for the developing fetal tissues. It has been known for many years that the synthesis rates of cholesterol in the fetus, the placenta and the yolk sac were very high when compared to adult tissues. The supporting fetal tissues also take up a significant amount of cholesterol from the maternal circulation in the form of LDL and HDL. We are presently trying to elucidate the mechanisms by which cholesterol is removed from the maternal circulation by these fetal tissues and determine if and how the transport can be regulated.
2) Examination of cholesterol and triglyceride absorption in neonates. Neonates require lipids, such as cholesterol, essential fatty acids and fat soluble vitamins, for optimal growth. Even with this vital requirement for lipid absorption, these animals have a smaller bile acid pool size than do adults; bile acids are believed to be required for lipid absorption from the intestine. Our goal is to better understand the process of lipid absorption in the neonate and determine dietary manipulations that can enhance the process when needed, such as the short bowel syndrome.
3) Determination of sterol balance in the adult under various metabolic and nutritional conditions. Sterol balance is the flux of sterol through the body. An animal with a high flux rate is usually non-responsive to dietary cholesterol. We are presently measuring flux rates of sterol and triglyceride under different metabolic conditions, such as pregnancy, and dietary manipulations, such as phytoestrogen.
Recent Publications
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McConihay, J.A., Honkomp, A.M., Granholm, N.A., and Woollett, L.A. 2000. Maternal high density lipoprotein-cholesterol concentrations affect fetal mass and extra-embryonic fetal tissue sterol metabolism in the mouse. J. Lipid Res. 41:424-432.
McConihay, J.A., Horn, P. and Woollett, L.A. 2001. The effect of maternal hypercholesterolemia on fetal sterol metabolism in the Golden Syrian hamster. J. Lipid Res. 42:1111-1119.
Wu, L., deBruin, A., Saavedra, H.I., Starovic, M. Trimboli, A., Yang, Y., Opavaska, J., Wilson, P., Ostrowski, M.C. Rosol, T.J., Woollett, L.A., Weinstein, M., Cross, J.C., Robinson, M.L., and Leone, G. 2003. Rb function in extraembryonic lineages is essential for embryonic development and viability. Nature 421:942-947.
Schmid, K.A. and Woollett, L.A. 2003. Differential effects of polyunsaturated fatty acids on sterol synthesis rates in adult and fetal tissues of the hamster: consequence of altered sterol balance. Am. J. Physiol. 285:G796-803.
Schmid, K.A., Davidson, W.S., Myatt, L. and Woollett, L.A. 2003. The transport of cholesterol across a placental cell monolayer: Implications for net transport of sterol from the maternal to fetal circulation. J. Lipid Res. 44:1909-1918.
Yao, L., and Woollett, L.A. 2004. Adult sterol metabolism is not affected by a positive sterol balance in the neonatal Golden Syrian hamster. Am. J. Physiol. Regulatory, integrative and comparative physiology 288:R561-R566.
Lipid and Obesity Research
Laboratory Staff
Tyler Stratton Katie Burke Lihang Yao Catherine Wilke Tom Xu Laura Woollett
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