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PERICYTES 2008
PERICYTES ALSO REGULATE WOUND HEALING AND NEOPLASIA
Pericytes, cells of mesenchymal origin are located along capillaries and postcapillary venules (Junqueira et al 2003). These cells have contractile function and contain myosin, actin and tropomyosin. They have long cytoplasmic processes and surround endothelial cells; also enclosed in their own basal lamina. Intimately related to the repair process because they are associated with neovascularization and connective tissue formation (Junqueira et al 2003). Other functions and morphological aspects relevant to wound healing and neoplasia include:
- VEGF is strongly related to angiogenesis in granulation tissue during wound healing and pericyte contractility. This is also relevant to use of platelet-rich plasma (PRP).
- During wound healing migrating endothelial cells are stabilized by pericytes and smooth muscle cells.
- Pericytes show osteogenic differentiation.
- PDGFR-beta signaling is important for recruitment, proliferation and functional activities of fibroblasts and pericytes during the early phases of wound healing.
- TIMP-2 and pericyte-derived TIMP-3 are associated with the stabilization of endothelial cell tubes in wound healing.
- Pericytes can differentiate into osteoblasts and form bone as well as serve as progenitors for chondrocytes and adipocytes.
- Pericytes are thus multipotent cells, and contribute to growth, wound healing, repair as well as pathological states. Also implicated in microvascular alterations related to diabetes, hypertension and neoplasia (Sims et al 1991). They have strong contractility properties and contract further to mediators of inflammation (Sims et al 1991). Also, pericytes are related to the inflammatory process and normal functioning of venules (Sims et al 1990). Sited at endothelial cell junctions and gaps (cohesive covering).
PERICYTES AND DISEASE PROCESSES: AFTER SIMS 2000
Pericytes are linked to:
- Microangiopathy of diabetes
- Scleroderma
- Hypertension
- Dementias
- ? abnormal calcification of blood vessels.
PERICYTES: SUMMARY OF FUNCTIONS: AFTER SHEPRO ET AL 1993
- Regulate endothelial proliferation and differentiation
- Contraction that affects inflammatory leakage
- Function as progenitor cells
- Synthesize and secrete wide variety of vasoactive autoregulatory agonists.
- Associated with the synthesis of the basement membrane and extracellular matrix (ECM).
- Participate in inflammatory events (Sims DE, 1991).
Pericytes are related to the inflammatory process and wound healing.
PERICYTE ACADEMIC REFERENCES
- Shinzara et al. Wound healing process of a full-thickness skin wound model in rats. Int Surg 2007; 92: 63-72.
- Maurer B et al. Angiogenesis. Possibilities for therapeutic intervention in rheumatic disease. Z Rheumatol 2007; 66: 304, 306-10.
- Wilkinson FL et al. Contribution of VCAF-positive cells to neovascularization and calcification in atherosclerotic plaque development. J Pathol 2007; 211: 362-9.
- Rajkumar VS et al. Platelet-derived growth factor-beta receptor activation is essential for fibroblast and pericyte recruitment during cutaneous wound healing. Am J Pathol 2006; 169: 2254-65.
- Farrington-Rock C et al. Chondrogenic and adipogenic potential of microvascular pericytes. Circulation 2004; 110: 2226-32.
- Pericytes: Chapter 11. Basic Histology, Junqueira et al. Text and Atlas. 10th edition, Lange, New York, 2003: 216.
- Sims DE. Recent advances in pericyte biology – implications for health and disease. Can J Cardiol 1991; 7: 431-43.
- Sims DE et al. Ultrastructure of pericytes in early stages of histamine-induced inflammation. J Morphol 1990; 206: 333-42.
- Sims DE et al. Diversity within pericytes. Clin Exp Pharmacol Physiol 2000; 27: 842-6.
- Shepro D et al. Pericyte physiology. FASEB J 1993; 7: 1031-8
 
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