Mineralization in serially passaged human alveolar bone cells

Abstract

Well-characterized human bone cell cultures have been regarded as auseful tool to study bone control mechanisms and also to analysebone/biomaterials interactions. In the present study, human alveolar bone cellswere cultured in α-minimal essential medium (α-MEM) containing 10%foetal bovine serum (FBS), 50 μg/ml ascorbic acid, 10 mM sodiumβ-glycerophosphate and either in the presence or in the absence of 10 nMdexamethasone (Dexa). Cultures were characterized concerning cellviability/proliferation, alkaline phosphatase (ALP), acid phosphatase (ACP) andtartraric acid resistant phosphatase (TRAP) activities, and formation ofmineralized areas. Cell proliferation increased gradually for approximately 20days. In the presence of Dexa, cells formed isolated or interconnectedmultilayered clusters that increased with culture time. Histochemical assaysrevealed strong positive reactions for ALP and calcium and phosphates deposits,mainly in relation t!o cells associated with the clusters. High levels of ALP activity (biochemicaldetermination) were observed. Cells cultured in the absence of Dexa showedsignificantly lower ALP activity and no calcium and phosphates deposits werepresent. Serially passaged cells kept the proliferation rate constant but adecrease in ALP activity was observed either in the presence or in the absenceof Dexa. The ability to form mineralized areas (cultures fed with Dexa) alsodecreased on serial subculture.