EFFECT OF FETAL SERUM ON FIBROBLAST PERICELLULAR MATRIX FORMATION

Hyaluronic acid (HA)-dependent pericellular matrices (PCM) play a role in embryonic differentiation of mesodermal cells. Fetal fibroblasts h ave significantly larger PCMs than postnatal fibroblasts. To determine if this property is intrinsic to fetal fibroblasts or induced by fact ors in the fetal environment, we studied the effect of fetal bovine se rum (FBS) of varying gestational age on human fetal, newborn, and adul t fibroblast PCM formation. Cultured human fetal, newborn, and adult f ibroblasts were plated in triplicate at a density of 1 x 10(5) cells a nd incubated in medium alone, medium containing 10% pooled PBS, or FBS from the first, second, or third trimesters. The cells were photograp hed and morphometric analysis of PCM was performed by the erythrocyte exclusion technique, PCM size was expressed as a ratio of the maximal width of the cell matrix to the maximal width of the cell. The unpaire d Student's t test was used for statistical analysis, The earlier the gestational age of FBS used, the larger the PCM observed in fetal and newborn fibroblasts, The PCM of fetal fibroblasts was significantly la rger (P < 0.001) than that of newborn and adult fibroblasts at each ge stational age of FBS tested (fetal much greater than newborn > adult). Medium containing pooled FBS caused a significant (P < 0.001) increas e in PCM size in all cell lines compared with serum-free medium, There are both intrinsic and extrinsic factors which affect PCM size. These factors which affect HA-dependent PCM size may contribute to a permis sive microenvironment for cell migration, proliferation, and developme nt which may be important for scarless fetal wound repair. (C) 1996 Ac ademic Press, Inc.