Changes in perlecan expression during vascular injury: role in the inhibition of smooth muscle cell proliferation in the late lesion.
OBJECTIVE
Vascular smooth muscle cells (SMCs), activated by growth factors after arterial injury, migrate and proliferate to expand the intima of the blood vessel. During intimal expansion, proliferation is suppressed and an increasingly large proportion of the neointimal mass is composed of newly synthesized extracellular matrix (ECM). We sough to determine whether the ECM heparan sulfate proteoglycan (HSPG) perlecan, which inhibits SMC proliferation in vitro, also accumulates and limits SMC proliferation during neointimal expansion.


RESULTS
Perlecan expression and accumulation were analyzed by immunohistochemistry and in situ hybridization during neointima formation after balloon catheter injury to the rat carotid artery. Perlecan expression was low in uninjured vessels and up to 7 days after injury, during maximal SMC proliferation. By 14 days after injury, perlecan was dramatically increased, and immunostaining remained heavy throughout the advanced lesion, 35 to 42 days after injury. Finally, explants of intimal tissue from 35- to 42-day neointimal lesions were digested with glycosaminoglycanases to determine whether endogenous HSPGs inhibit intimal SMC proliferation. SMCs within HS-depleted, but not chondroitinase ABC-treated or mock-incubated, explants were found to proliferate in response to platelet-derived growth factor BB.


CONCLUSIONS
HSPGs, such as perlecan, may inhibit the proliferative response of SMCs after vascular injury.
Kinsella
Michael G
MG
Department of Pathology, University of Washington, and the Hope Heart Institute, Seattle, Wash 98104, USA. mkinsella@hopeheart.org
Tran
Phan-Kiet
PK
Weiser-Evans
Mary C M
MC
Reidy
Michael
M
Majack
Richard A
RA
Wight
Thomas N
TN
D000818:Animals; D000077214:Becaplermin; D020212:Carotid Artery Injuries / Q000378:metabolism / Q000473:pathology*; D002404:Catheterization / Q000009:adverse effects; D002455:Cell Division / Q000187:drug effects; D005109:Extracellular Matrix / Q000378:metabolism; D019812:Heparan Sulfate Proteoglycans / Q000096:biosynthesis* / Q000235:genetics; D019763:Heparin Lyase / Q000494:pharmacology; D006965:Hyperplasia; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D009924:Organ Culture Techniques; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D020574:Proto-Oncogene Proteins c-sis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017539:Tunica Intima / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
D019812:Heparan Sulfate Proteoglycans; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; C071927:perlecan; D000077214:Becaplermin; D019763:Heparin Lyase