Effect of hyaluronan on adult and fetal fibroblast proliferation and collagen synthesis: in vitro study

Abstract

In this study, we hypothesized that there is a significant difference between the proliferation rate and collagen and elastic fiber content of the fetal and adult type of cultured fibroblast due to higher hyaluronan (HA) content in fetal tissues. To address this issue, we examined the difference in the proliferation rate of fetal and adult cultured fibroblasts by evaluating the time for being confluent and the morphology of the cells; in addition, granular (rough) endoplasmic reticulum and the Golgi apparatus were also observed by both light microscopy and transmission (TEM) and scanning electron microscopy (SEM) in subgroups that were treated with HA or left untreated. Addition of HA to the culture medium was started at day 3. The average time difference for confluence of the cells between the treated and untreated adult fibroblast groups was statistically significant (P<0.001). In the untreated adult fibroblast group, cells showed less granular endoplasmic reticulum and Golgi apparatus, whereas large and dilated endoplasmic reticulum was seen in treated adult and untreated fetal fibroblasts. Our study showed that adult fibroblasts can show similar changes to the fetal fibroblasts in response to elevated levels of HA in vitro. It is likely that HA may play important roles in fibroblast morphology, proliferation, and differentiation.