Heparan sulfate side chains have a critical role in the inhibitory effects of perlecan on vascular smooth muscle cell response to arterial injury.

Perlecan is a proteoglycan composed of a 470-kDa core protein linked to three heparan sulfate (HS) glycosaminoglycan chains. The intact proteoglycan inhibits the smooth muscle cell (SMC) response to vascular injury. Hspg2(Δ3/Δ3) (MΔ3/Δ3) mice produce a mutant perlecan lacking the HS side chains. The objective of this study was to determine differences between these two types of perlecan in modifying SMC activities to the arterial injury response, in order to define the specific role of the HS side chains. In vitro proliferative and migratory activities were compared in SMC isolated from MΔ3/Δ3 and wild-type mice. Proliferation of MΔ3/Δ3 SMC was 1.5× greater than in wild type (P < 0.001), increased by addition of growth factors, and showed a 42% greater migratory response than wild-type cells to PDGF-BB (P < 0.001). In MΔ3/Δ3 SMC adhesion to fibronectin, and collagen types I and IV was significantly greater than wild type. Addition of DRL-12582, an inducer of perlecan expression, decreased proliferation and migratory response to PDGF-BB stimulation in wild-type SMC compared with MΔ3/Δ3. In an in vivo carotid artery wire injury model, the medial thickness, medial area/lumen ratio, and macrophage infiltration were significantly increased in the MΔ3/Δ3 mice, indicating a prominent role of the HS side chain in limiting vascular injury response. Mutant perlecan that lacks HS side chains had a marked reduction in the inhibition of in vitro SMC function and the in vivo arterial response to injury, indicating the critical role of HS side chains in perlecan function in the vessel wall.

Gotha L ，Lim SY ，Osherov AB ，Wolff R ，Qiang B ，Erlich I ，Nili N ，Pillarisetti S ，Chang YT ，Tran PK ，Tryggvason K ，Hedin U ，Tran-Lundmark K ，Advani SL ，Gilbert RE ，Strauss BH ... -  《-》

Perlecan heparan sulfate deficiency impairs pulmonary vascular development and attenuates hypoxic pulmonary hypertension.

Excessive vascular cell proliferation is an important component of pulmonary hypertension (PH). Perlecan is the major heparan sulfate (HS) proteoglycan in the vascular extracellular matrix. It binds growth factors, including FGF2, and either restricts or promotes cell proliferation. In this study, we have explored the effects of perlecan HS deficiency on pulmonary vascular development and in hypoxia-induced PH. In normoxia, Hspg2(Δ3/Δ3) mice, deficient in perlecan HS, had reduced pericytes and muscularization of intra-acinar vessels. Pulmonary angiography revealed a peripheral perfusion defect. Despite these abnormalities, right ventricular systolic pressure (RVSP) and myocardial mass remained normal. After 4 weeks of hypoxia, increases in the proportion of muscularized vessels, RVSP, and right ventricular hypertrophy were significantly less in Hspg2(Δ3/Δ3) compared with wild type. The early phase of hypoxia induced a significantly lower increase in fibroblast growth factor receptor-1 (FGFR1) protein level and receptor phosphorylation, and reduced pulmonary artery smooth muscle cell (PASMC) proliferation in Hspg2(Δ3/Δ3). At 4 weeks, FGF2 mRNA and protein were also significantly reduced in Hspg2(Δ3/Δ3) lungs. Ligand and carbohydrate engagement assay showed that perlecan HS is required for HS-FGF2-FGFR1 ternary complex formation. In vitro, proliferation assays showed that PASMC proliferation is reduced by selective FGFR1 inhibition. PASMC adhesion to fibronectin was higher in Hspg2(Δ3/Δ3) compared with wild type. Perlecan HS chains are important for normal vascular arborization and recruitment of pericytes to pulmonary vessels. Perlecan HS deficiency also attenuates hypoxia-induced PH, where the underlying mechanisms involve impaired FGF2/FGFR1 interaction, inhibition of PASMC growth, and altered cell-matrix interactions.

Chang YT ，Tseng CN ，Tannenberg P ，Eriksson L ，Yuan K ，de Jesus Perez VA ，Lundberg J ，Lengquist M ，Botusan IR ，Catrina SB ，Tran PK ，Hedin U ，Tran-Lundmark K ... -  《-》

Removal of heparan sulfate by heparinase treatment inhibits FGF-2-dependent smooth muscle cell proliferation in injured rat carotid arteries.

Kinsella MG ，Irvin C ，Reidy MA ，Wight TN ... -  《ATHEROSCLEROSIS》

Increased intimal hyperplasia and smooth muscle cell proliferation in transgenic mice with heparan sulfate-deficient perlecan.

Tran PK ，Tran-Lundmark K ，Soininen R ，Tryggvason K ，Thyberg J ，Hedin U ... -  《-》

Heparan sulfate in perlecan promotes mouse atherosclerosis: roles in lipid permeability, lipid retention, and smooth muscle cell proliferation.

Tran-Lundmark K ，Tran PK ，Paulsson-Berne G ，Fridén V ，Soininen R ，Tryggvason K ，Wight TN ，Kinsella MG ，Borén J ，Hedin U ... -  《-》