Biomedical Engineering Reference
In-Depth Information
(b) Recent i ndings from our laboratory and others demonstrate that apoC-
III, alone or as a component of apoB lipoproteins, directly promotes
the expression of adhesion molecules in vascular endothelial cells and
monocytes, enhancing monocyte adhesion.
3. ApoE is another small apolipoprotein commonly found on the surface of
triglyceride-rich lipoproteins and HDL.
(a) ApoE facilitates apoB lipoprotein clearance by binding with hepatic
receptors.
(b) h ere is limited evidence suggesting apoE may directly inhibit adhesion
molecule expression in vascular cells.
Definition of Terms
Atherosclerosis:
A chronic inl ammatory disease af ecting the intima and media of
large- and medium-sized arteries. h is inl ammatory process leads to the formation
of atherosclerotic plaques, containing lipid and i brous tissue. h e plaques rich in
macrophages ot en rupture, causing the formation of a thrombus that will rapidly block
blood l ow, and thereby leading to ischemic death of the cardiac muscle fed by the
artery.
Endothelial cells:
h e thin layer of cells that line the interior surface of blood vessels, forming
an interface between circulating blood in the lumen and the rest of the vessel wall.
Lipoproteins:
A biochemical assembly that contains both proteins and lipids. Examples
include the high-density and low-density lipoproteins that enable fats (triglyceride,
phospholipid, cholesterol ester, and free cholesterol) to be carried in the bloodstream.
In addition to its lipid content, VLDL also carries protein components on its surface
called apolipoproteins, such as apoC-III and apoE.
Monocytes:
A type of white blood cell that in response to chemotactic signals can move
quickly to sites of infection or inl ammation in the tissues and divide/dif erentiate into
macrophages and dendritic cells to elicit an immune response.
Signal transduction:
Any process by which a cell converts one kind of signal or stimulus
into another. Most processes of signal transduction involve ordered sequences of
biochemical reactions inside the cell, which are carried out by enzymes, activated by
second messengers, resulting in a signal transduction pathway.
References
Aikawa, M. and P. Libby. 2004. h e vulnerable atherosclerotic plaque: pathogenesis and
therapeutic approach. Cardiovasc. Pathol. 13: 125-138.
Aikawa, M. and S. Sugiyama, C.C. Hill, S.J. Voglic, E. Rabkin, Y. Fukumoto, F.J. Schoen, J.L.
Witztum, and P. Libby. 2002. Lipid lowering reduces oxidative stress and endothelial cell
activation in rabbit atheroma. Circulation 106: 1390-1396.
Ali, K. and M. Middleton, E. Pure, and D.J. Rader. 2005. Apolipoprotein E suppresses the
type I inl ammatory response in vivo. Circ. Res. 97: 922-927.
