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

Background: Although it is recognized that the extracellular matrix is important for cell proliferation, migration and metabolism of growth factors, the regulation of the synthesis of hyaluronan and chondroitin sulphate proteoglycan (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 incubation medium was measured by a combination of digestion with testicular hyaluronidase and precipitation of [(SO42-)-S-35]-labelled material with ethanol and trichloroacetic acid. Hyaluronan was estimated using a radiometric assay. 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 with glucose and hGH (2P < 0.01), but showed no change with insulin. Conclusions: The present data obtained with human arterial smooth muscle cells in vitro showed that glucose, insulin and hGH can influence the accumulation of hyaluronan and CSPG. These observations may be relevant for an understanding of diabetic macroangiopathy.