Effects of hyaluronan on cell proliferation and proteoglycan synthesis in rabbit ligamental cells

The effect of hyaluronan (HA) on cell proliferation and synthesis of proteoglycan (PG) in rabbit ligamental cells was examined in vitro. HA promoted the incorporation of 35S-sulfate in a concentration-dependent manner, significantly at 100 micrograms/ml and upward, without effect on cell proliferation. The chromatographic profile of the 35S-labelled materials extracted with 4 M guanidine hydrochloride by Sepharose CL-2B was different in the HA-treated cells as compared with untreated cells. Although the radioactivities of the low-molecular fraction peaked at Kav 0.71 did not change, those of the high-molecular fraction (Kav 0.30-0.50) increased with treatment of HA. Ligamental cells expressed the mRNA of the PG family's versican and aggrecan (large-molecular weight PGs), biglycan and decorin (small-molecular weight PGs) in dot blot analysis. Although the mRNA expression of aggrecan, biglycan and decorin did not change, that of versican increased upon treatment with HA. These findings suggest that HA is involved in promoting production of the large-molecular-weight PG versican, and in facilitating extracellular matrix formation.