The expression of transforming growth factor-beta and interleukin-1 beta mRNA and the response to 1,25(OH)(2)D-3, 17 beta-estradiol, and testosteroneis age dependent in primary cultures of mouse-derived osteoblasts in vitro

The aim of the present study was to examine the hypothesis that primary cul tures of osteoblasts obtained from bones of young animals respond to hormon es better than cell cultures obtained from old animals. We studied in cultu red osteoblastic cells the effects of 1,25(OH)(2)D-3 and sex steroid hormon es on several mouse osteoblastic phenotypic expressions including transform ing grow th factor-beta (TGF-beta) and interleukin-1 beta (IL-1 beta) mRNAs . Second passages of long bone-derived osteoblastic cells from young donors (5-12 wk) and old donors (10-12 mo old) were used for this study. The cell s obtained from old animals had decreased ALP activity and cAMP compared wi th cells obtained from young animals with no change in collagen production and mineralization. The addition of 17 beta-estradiol and testosterone incr eased ALP activity and mineralization in the cultured cells from both age g roups and collagen production in cells obtained from old mice. Using in sit u hybridization IL-1 beta and TGF-beta mRNA expression was observed to be h igher in the osteoblasts from young than from old donors, 1,25(OH)(2)D-3 in creased IL-1 beta mRNA expression in the cells derived from young mice, Tes tosterone and 17 beta-estradiol inhibited IL-1 beta mRNA expression only in cells derived from young mice. Sex steroid hormones did not change TGF-bet a mRNA expression in any of the cell lines, but 1,25(OH)(2)D-3 increased it s expression in cells derived from old donors. The results of the present s tudy indicate that cells obtained from old mice are generally less active t han those obtained from young animals.