A chemically modified dextran inhibits smooth muscle cell growth in vitro and intimal in stent hyperplasia in vivo.
OBJECTIVE
Intimal smooth muscle cell (SMC) hyperplasia is a main component of the arterial wall response to injury. We have investigated the capacity of a water-soluble nonanticoagulant functionalized dextran (E9) in inhibition of SMC growth in vitro and in vivo.


METHODS
E9 was obtained with chemical substitutions with anionic and hydrophobic groups on the dextran backbone. SMC proliferation (cell counting, thymidine uptake, cell cycle analysis) was followed in culture in the presence of E9. Western blot analysis against phosphorylated mitogen-activated protein kinase (MAPK), extracellular signal-regulated protein kinase 1/2, and assessment of MAPK activity on serum-stimulated SMCs also were investigated. Binding/displacement experiments, electron microscopy, and cell fractionations were used to follow the binding and internalization of radiolabeled and fluorescentlabeled E9. New Zealand white rabbit iliac arteries were injured with balloon dilatation and stent deployment. Animals were treated for 14 days with saline solution or E9 (5 mg/kg injected subcutaneously, twice daily). Morphometric analyses were carried out in each group (n = 6 arteries, 18 sections).


RESULTS
Nonanticoagulant E9 inhibited SMC proliferation in vitro. Tyrosine phosphorylation of MAPK 1/2 and MAPK activity were inhibited with E9 within 5 minutes of incubation. The binding and rapid cytoplasmic internalization of the synthetic compound was evidenced, but, in contrast to heparin, we did not detect any nuclear localization of the antiproliferative E9. In the in vivo model, qualitative modifications of neointimal structure with a thinner fibrocellular neointima were noticed after E9 treatment. Morphometric analyses of stented arteries in E9-treated animals indicated an important reduction (P <.01) of intimal growth: 33% and 45% for intimal area and intima/media ratio, respectively.


CONCLUSIONS
Cytoplasmic internalization of the synthetic polysaccharide correlated to the SMC growth inhibition that involved the MAPK pathway. In vivo inhibition of intimal instent hyperplasia with this nonanticoagulant derived dextran is shown providing a new candidate for a potential selective treatment of SMC proliferation.
Deux
Jean-François
JF
INSERM ERIT-M 204, X Bichat Medical School, Bat INSERM 13, 46 Rue Henri Huchard, 75877 Paris Cedex 18, France.
Prigent-Richard
Sandrine
S
d'Angelo
Gisela
G
Feldman
Laurent J
LJ
Puvion
Edmond
E
Logeart-Avramoglou
Delphine
D
Pellé
Anne
A
Boudghène
Frank P
FP
Michel
Jean-Baptiste
JB
Letourneur
Didier
D
D000818:Animals; D000925:Anticoagulants / Q000138:chemical synthesis / Q000494:pharmacology* / Q000627:therapeutic use*; D003911:Dextrans / Q000138:chemical synthesis / Q000494:pharmacology* / Q000627:therapeutic use*; D004195:Disease Models, Animal; D006965:Hyperplasia / Q000188:drug therapy* / Q000209:etiology* / Q000473:pathology; D007083:Iliac Artery / Q000187:drug effects / Q000473:pathology; D066298:In Vitro Techniques; D009130:Muscle, Smooth / Q000187:drug effects* / Q000254:growth & development* / Q000473:pathology; D011817:Rabbits; D015607:Stents / Q000009:adverse effects*; D017539:Tunica Intima / Q000187:drug effects* / Q000473:pathology
D000925:Anticoagulants; D003911:Dextrans