Production of hyaluronan and chondroitin sulphate proteoglycans from humanarterial smooth muscle - the effect of glucose, insulin, IGF-1 or growth hormone

Background: Although it is recognized that the extracellular matrix is impo rtant for cell proliferation, migration and metabolism of growth factors, t he regulation of the synthesis of hyaluronan and chondroitin sulphate prote oglycan (CSPG) in the vessel wall is poorly understood. Objective: To examine the role of glucose, insulin, IGF-I and human growth hormone (hGH) on the accumulation of hyaluronan and CSPG using cultures of human aortic smooth muscle cells. Methods: The cultures were exposed for 36 h. The CSPG content in the incuba tion medium was measured by a combination of digestion with testicular hyal uronidase and precipitation of [(SO42-)-S-35]-labelled material with ethano l and trichloroacetic acid. Hyaluronan was estimated using a radiometric as say. Results: Glucose and insulin reduced the amount of synthesized hyaluronan ( 2P < 0.01). Stimulation of synthesis was seen with hGH (2P < 0.01), whereas no effect was observed with IGF-I. The production of CSPG was increased wi th glucose and hGH (2P < 0.01), but showed no change with insulin. Conclusions: The present data obtained with human arterial smooth muscle ce lls in vitro showed that glucose, insulin and hGH can influence the accumul ation of hyaluronan and CSPG. These observations may be relevant for an und erstanding of diabetic macroangiopathy.