B P4 C24 The Vascular Biology of Atherosclerosis Flashcards
This molecule serve as a cofactor for antithrombin III, causing a conformational change that allows this inhibitor to bind to and inactivate thrombin
Heparan Sulfate
Molecule that binds thrombin molecules and can exert antithrombotic properties by activating proteins S and C
Thrombomodulin
The _____ cell of the arterial intima constitutes the crucial contact surface with blood
Endothelial cell (EC)
Should a thrombus begin to form, the normal EC possesses potent fibrinolytic mechanisms associated with its surface. The EC can produce both:
Tissue-plasminogen activator (t-PA)
and
Urokinase-type plasminogen activator (u-PA)
Catalyze the activation of plasminogen into plasmin, a fibrinolytic enzyme
t-PA and u-PA
The second major cell type of the normal artery wall, the _____, has many important functions in normal vascular homeostasis, as a target of therapies in cardiovascular medicine and in the pathogenesis of arterial diseases
Smooth muscle cell (SMC)
However, in larger arteries involved in atherosclerosis, abnormal smooth muscle contraction may cause _____, a complication of atherosclerosis that may impede blood flow.
Vasospasm
Death of SMCs may promote:
Destabilization of atheromatous plaques
Ectatic remodeling
Aneurysm formation
In the descending aorta and arteries of the lower body, the regional ___ serves as the source of smooth muscle precursors.
Mesoderm
However, in arteries of the upper body, SMCs can derive from a completely different germ layer—the _____,rather than mesoderm
Neuroectoderm
The heterogeneity of SMCs may have direct clinical implications to help understand several common observations, such as the propensity of certain arteries or regions of arteries to develop atherosclerosis or heightened responses to injury (e.g., _____), and medial degeneration (e.g., ____)
Propensity to develop atherosclerosis/heightened response to injury (pLAD)
Medial degeneration (proximal aorta in Marfan Syndrome)
The vasa vasorum and nerve endings localize in this layer of the arterial wall
Adventitia
This structure appears well adapted to the storage of the kinetic energy of left ventricular systole by the walls of great arteries.
Tunica Media
The first steps in human atherogenesis remain largely conjectural, but the integration of observations of tissues obtained from young humans with the results of experimental studies of atherogenesis in animals provides hints in this regard.
On initiation of an atherogenic diet, typically rich in cholesterol and saturated fat, _____.
Small lipoprotein particles accumulate in the intima (steps 1 and 2)
Lipoprotein particles bound to _____ have increased susceptibility to oxidative or other chemical modifications, considered by many to contribute to the pathogenesis of early atherosclerosis (step 2)
Proteoglycan
Another hallmark of atherogenesis is ____
Leukocyte recruitment and accumulation
Members of the immunoglobulin (Ig) superfamily include:
VCAM-1
CD106
This integrin is characteristically expressed by only those classes of leukocytes that accumulate in nascent atheroma—monocytes and T cells.
Very late antigen-4 (VLA-4)
The location of the lesion predilection at _____ portions of arteries after branch points or bifurcations at flow dividers, suggests a hydrodynamic basis for early lesion development.
Proximal
Arteries without many branches (e.g., the internal mammary and radial arteries) tend not to develop atherosclerosis.
_____ can reduce oxidative stress by catabolizing the reactive and injurious superoxide anion.
SOD
Endothelial NOS produces the well-known endogenous vasodilator _____.
Nitric oxide
Beyond its vasodilating actions, NO can resist inflammatory activation of endothelial functions, including the expression of VCAM-1.
NO appears to exert this anti-inflammatory action at the level of gene expression by interfering with the transcriptional regulator nuclear factor kappa B (NF-kB).
IkBa, an intracellular inhibitor of this important transcription factor. NFkB regulates numerous genes involved in inflammatory responses in general and in atherogenesis in particular.
Pulsatile (unidirectional) laminar flow induced the pivotal transcription factors (__), which coordinately elicit a palette of atheroprotective function.
Krüppel-like factor [KLF]-2
KLF4
Nuclear factor erythroid 2–related factor [Nrf]-2
The monocyte, once recruited to the arterial intima, can imbibe lipid and become a _____.
Foam cell or lipid-laden macrophage (Step 5)
Instead of the classic LDL receptor, various _____ receptors appear to mediate the excessive lipid uptake characteristic of foam cell formation
Scavenger receptors
The factors that trigger macrophage cell division in the atherosclerotic plaque probably include hematopoietic growth factors such as:
Macrophage colony-stimulating factor (M-CSF)
Granulocyte-macrophage colony-stimulating factor (GM-CSF)
Interleukin-3 (IL-3)