TGFβ-1 mRNA Expression and Proliferation of Human Osteoblastic Cells in Nonosteoporotic and Osteoporotic Women under Influence of TGFβ-1 and IGF-I

Abstract

Currently, primary osteoporosis is the most frequent metabolic disease in women after menopause [1]. The resulting loss of bone mass is accompanied by an increased risk of skeletal fragility. One reason for the development of osteoporosis might be an impaired function of mature osteoblasts. To evaluate the involvement of specific growth factors in bone remodeling, cell cultures of osteoblastic cells derived from nonosteoporotic and osteoporotic postmenopausal women were established. The influences of TGFβ-1 and IGF-I on proliferation and mRNA expression of TGFβ-1 were investigated by [³H]-thymidine incorporation and competitive RT-PCR.

We found IGF-I to have no significant effect on proliferation in cells of osteoporotic and nonosteoporotic patients. In contrast, differences were found in TGFβ-1 mRNA expression after application of IGF-I. Application of TGFβ-1 enhanced its own mRNA expression in both groups in a similar manner. Whereas the proliferation of cells of nonosteoporotic patients was inhibited by (10⁻¹⁰ M) TGFβ-1, this treatment led to an increased proliferation of cells of osteoporotic patients.