Tissue Development, Repair, and Remodeling - Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems - page 728

Table 11.13. and dense granules at repair sites

(Source: [ 1377 ]; CXCL4: chemokine CXC motif-containing ligand-4, also termed platelet factor-
4; HETE: hydroxyeicosatetranoic acid; IGFBP: insulin-like growth factor-binding protein).

Released content of platelet, in particular from α

Substance Effect

α Granules
Platelet-derived growth factor

Matrix deposition

α

Transforming growth factor- Epithelialization

β

Transforming growth factor- Matrix deposition

CXCL4 Activation of growth factors

IGFBP3 Matrix deposition

β -Thromboglobulin Activation of growth factors

Dense granules

Adenosine diphosphate Platelet aggregation

Calcium Platelet aggregation

Serotonin Vasoconstriction

Cytosol

von Willebrand factor Mediator of platelet adhesion

Fibronectin Platelet aggregation

Fibrinogen Platelet aggregation

Thrombospondin Platelet aggregation

Coagulation factor V Hemostasis

Platelet-activating factor Platelet activation

Thromboxane-A2 Vasoconstriction

12-HETE Vasoconstriction

Other
Vascular endothelial growth factor

Angiogenesis

11.6.3 Myofibroblasts

Myofibroblasts, or mesenchyme-like interstitial cells, are contractile cells that
participate in wound healing, fibrosis, and tumors, as well as vascular diseases
with vessel wall remodeling, such as arterial restenosis and aneurysms. Myofibrob-
last markers include

α smooth muscle actin, or α -actin-2, intermediate filament

vimentin, and desmin.
Myofibroblasts can develop under concomitant mechanical and biochemical
stimuli from [ 1474 ]: (1) fibroblasts and fibrocytes, the latter being defined as
CD34

+ (hematopoietic progenitor cell antigen), CD45 + (PTPRc), and collagen-

mesenchymal progenitors; (2) smooth myocytes; 67 (3) pericytes (4) endothelial
and epithelial cells after reversible epit(endo)thelial-mesenchymal transition; (5)

1 +

67 Activated myofibroblasts and smooth myocytes share markers, such as

α

smA, transgelin (a.k.a.

α

smooth muscle protein SM22 or SM22 ), caldesmon, vinculin, and calponin H .