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The effects of IGF‐I and IGF‐II on proliferation and differentiation of human osteoblasts and interactions with growth hormone
Author(s) -
Langdahl,
Moustapha Kassem,
Møller,
; Eriksen
Publication year - 1998
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1046/j.1365-2362.1998.00265.x
Subject(s) - endocrinology , medicine , osteoblast , alkaline phosphatase , stromal cell , growth factor , cell growth , insulin like growth factor , in vitro , chemistry , somatomedin , biology , receptor , biochemistry , enzyme
Background We have previously shown that growth hormone (GH) consistently stimulates proliferation of human osteoblasts in vitro . In rat osteoblasts, GH augments the effects of insulin‐like growth factor (IGF) I on cell proliferation and differentiation. We therefore investigated the effects of IGF‐I and ‐II alone and in combination with GH on human osteoblasts in vitro . Methods Human osteoblast‐like cells (HOB) were established from trabecular explants ( n = 18) and human marrow stromal cells (HMS) from marrow aspiration ( n = 21). The cell cultures were stimulated with IGF‐I or IGF‐II (1, 10 or 100 ng mL −1 ) alone, in combination with hGH (100 ng mL −1 ) or after prestimulation with hGH. Results IGF‐I alone, in combination with hGH and after pretreatment with hGH, increased proliferation of HOB and HMS by 49–190% ( P < 0.05–0.01). IGF‐II alone, in combination with hGH and after pretreatment with hGH increased proliferation of HOB by 57–158% ( P < 0.01). In HMS only IGF‐II in combination with hGH and after prestimulation with hGH increased proliferation. IGF‐I alone and in combination with hGH decreased alkaline phosphatase (AP) in both cell types. IGF‐II did not affect AP in HOB, but increased AP in HMS, this effect was abolished by hGH. In HOB, collagen production (PICP) was increased by IGF‐II but unaffected by IGF‐I. In HMS, PICP was decreased by IGF‐I and ‐II but increased by hGH. Co‐stimulation further increased PICP. Conclusion IGF‐I and ‐II exerted proliferative effects on both HOB and HMS. Co‐stimulation with GH exhibited synergism in enhancing the proliferative response. In HMS prestimulation improved the proliferative response significantly. The effects of the IGFs on differentiation are more complex and dependent on cell maturation and of the IGF used.