Glycosaminoglycans are important structural components in the skin and exist as various proteoglycan forms, except hyaluronic acid. Heparan sulfate (HS), one of the glycosaminoglycans, is composed of repeated disaccharide units, which are glucuronic acids linked to an N-acetyl-glucosamine or its sulfated forms. To investigate acute ultraviolet (UV)-induced changes of HS and HS proteoglycans (HSPGs), changes in levels of HS and several HSPGs in male human buttock skin were examined by immunohistochemistry and real-time quantitative polymerase chain reaction (qPCR) after 2 minimal erythema doses (MED) of UV irradiation (each n = 4-7). HS staining revealed that 2 MED of UV irradiation increased its expression, and staining for perlecan, syndecan-1, syndecan-4, CD44v3, and CD44 showed that UV irradiation increased their protein levels. However, analysis by real-time qPCR showed that UV irradiation did not change mRNA levels of CD44 and agrin, and decreased perlecan and syndecan-4 mRNA levels, while increased syndecan-1 mRNA level. As HS-synthesizing or -degrading enzymes, exostosin-1 and heparanase mRNA levels were increased, but exostosin-2 was decreased by UV irradiation. UV-induced matrix metalloproteinase-1 expression was confirmed for proper experimental conditions. Acute UV irradiation increases HS and HSPG levels in human skin, but their increase may not be mediated through their transcriptional regulation.
Adult ; Agrin/genetics ; Antigens, CD44/genetics ; Base Sequence ; DNA Primers/genetics ; Gene Expression/radiation effects ; Glucuronidase/genetics ; Heparan Sulfate Proteoglycans/genetics/*metabolism ; Heparitin Sulfate/metabolism ; Humans ; Male ; Matrix Metalloproteinase 1/genetics ; N-Acetylglucosaminyltransferases/genetics ; RNA, Messenger/genetics/metabolism ; Skin/*metabolism/*radiation effects ; Skin Aging/genetics/physiology ; Syndecan-1/genetics ; Syndecan-4/genetics ; Ultraviolet Rays/*adverse effects ; Young Adult

OBJECTIVETo investigate the effect of pravastatin on the proliferation of rat vascular smooth muscle cells (VSMCs) and expression of syndecan-4 protein induced by tumor necrosis factor-alpha (TNF-alpha).

METHODSVSMCs cultured in vitro were exposed to 20 ng/ml TNF-alpha, 10 micromol/ml pravastatin, 20 micromol/ml pravastatin, 10 micromol/ml pravastatin with 20 ng/ml TNF-alpha, or 20 micromol/ml pravastatin with 20 ng/ml TNF-alpha for 24 h. The proliferation of the VSMCs was determined by non-radioactive MTS/PMS assay and the expression of syndecan-4 protein was detected by Western blotting using anti-syndecan-4 antibody.

RESULTSCompared to the control group, TNF-alpha at 20 ng/ml significantly stimulated the proliferation of rat VSMCs (P<0.05). Pravastatin alone produced no obvious effect on VSMCs growth (P>0.05), but significantly inhibited TNF-alpha-induced VSMC proliferation (P<0.05). The expression of syndecan-4 protein in the VSMCs was significantly enhanced by 20 ng/ml TNF-alpha (P<0.01). Pravastatin alone did not affect the expression of syndecan-4 protein (P>0.05), but significantly inhibited TNF-alpha-induced enhancement of syndecan-4 protein expression (P<0.01).

CONCLUSIONPravastatin can inhibit the proliferation and syndean-4 protein expression in rat VSMCs induced by TNF-alpha in vitro.

Animals ; Anticholesteremic Agents ; pharmacology ; Aorta, Thoracic ; cytology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Pravastatin ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Syndecan-4 ; genetics ; metabolism ; Tumor Necrosis Factor-alpha ; pharmacology