Smooth Myocytes - Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems - page 420

Table 8.14. Examples of products of vascular smooth myocytes (ABP: actin-binding protein;
ASP: actin-severing protein).

Contractile proteins Actin, ABP, ASP, myosin

Adhesion molecules Cadherin, integrin

Matrix components Elastin, collagen-1/3

Proteoglycans (PGe2, PGi2)
Glycoproteins (emilin)

Growth factors PDGF, CSF1-CSF3

Chemokine CCL2

Cytokines IL1/6, TNF

Enzymes NOS, COx,

PLC

β γ

1/3, PLC 1,

PKC, MAPKs

detachment and apoptosis. Proteoglycan-bound pericellular serpin-E2 forms a
complex with plasmin and tPA that can be endocytosed by LRP1 scavenger 44
present on the vSMC plasma membrane.
Similarly, the complex hyaluronan-binding protein HABP2 made of clotting
factor-VII and activator serine protease (a.k.a. FSAP), also synthesized by the liver,
circulating ( g/ml) as a zymogen, is activated by autocatalysis after binding

to anionic (sulphated) glycosaminoglycans or nucleic acids. It cleaves and activates
coagulation factor-VII, PDGFbb homodimer, and prourokinase [ 745 ]. The proteic
complex HABP2 is inhibited by circulating serpins as well as protease nexin-1
(PN1) in the vSMC pericellular space. The HABP2-PN1 complex is then cleared
by vascular smooth myocytes via LRP1-dependent endocytosis.

∼ 10

8.5.6 Vascular Smooth Myocyte Production

The vascular smooth myocyte undergoes direct and indirect stimuli, essentially from
its extracellular matrix, cells of the adjacent layer of the vessel wall, and blood flow.
It then produces several types of substances (Table 8.14 ).
Myocardin-related transcription factors, coactivators of the transcription factor
serum response factor, are required in vascular smooth myocyte as well as car-
diomyocyte differentiation. Serum response factor regulates genes involved in cell
proliferation, migration, cytoskeletal dynamics, and myogenesis [ 776 ].

44 A.k.a.

α

2-macroglobulin receptor.