Diphenylhydantoin Affects Glycosaminoglycans and Collagen Production by Human Fibroblasts from Cleft Palate Patients

During embryonic development, the proper production of extracellular matrix molecules mediates morphogenetic processes involved in palatogenesis. In the present study, we investigated whether any differences exist in glycosaminoglycan (GAG) and collagen synthesis between palate fibroblasts from infants, with or without cleft palate, in two age ranges. Subsequently, the effects of diphenylhydantoin (PHT), a teratogen known to induce cleft palate in human and mammalian newborns, on extracellular matrix (ECM) production were studied. We found that cleft palate fibroblasts (CPFs) synthesize greater amounts of GAG and collagen than normal fibroblasts (NFs). CPFs produced less cellular hyaluronic acid (HA) and more sulphated GAG. HA was the principal GAG species in the medium, and its percentage was lower in one- to three-year-old CPFs. Cleft palate fibroblasts produced more extracellular chondroitin 4- and 6-sulphate (CS) and dermatan sulphate (DS). Associated with a higher production of sulphated GAG, we observed a higher synthesis of type III and type I collagen with a normal ratio of alpha2(I) to alpha1(I) chains. PHT treatment of NFs reduced collagen and GAG synthesis, with a marked effect on sulphated GAG. The drug changed collagen synthesis, whereas it did not affect GAG production in CPFs whose phenotype may already be impaired. These findings indicate that, in CPFs, modifications in the pattern of ECM components, which are most likely responsible for the anomalous development, persist in infants. In addition, NFs and CPFs with a different phenotype respond differently to PHT treatment.