Effect on osteoblasts

Fluorid ions stimulate bone formation by a direct mitogenic effect on osteoblasts mediated via protein kinase activation and other pathways. Further to these cellular effects, fluorides alter hydroxyapatite crystals in the bone matrix. In low doses, fluorides induce lamellar bone, while at higher doses abnormal woven bone with inferior quality is formed. The effect of fluorides on normal and abnormal (e.g. osteoporotic) bone therefore depends on the dose administered. 

Fluoride stimulates bone formation by protein kinase activation mediated effects on osteoblasts. Fluorides have been used in the treatment of osteoporosis, but their anti-fracture effect is not undisputed. 

Kim, L., Rao, A.V., and Rao, L.G. 2003. Lycopene II-effect on osteoblasts The carotenoid lycopene stimulates cell proliferation and alkaline phosphatase activity of SaOS-2 cells. J Med Food 6 79-86. 

In summary, IL-1 and TNF-a activate mature osteoclasts indirectly via a primary effect on osteoblasts and by inhibiting osteoclast apoptosis. In addition, they increase osteoclast formation either by directly stimulating the proliferation of osteoclast precursors or by increasing the pro-osteoclastogenic capacity of bone stromal cells. Although in vitro TNF-a and IL-1 can apparently induce the development of TRAP+ osteoclasts in the absence of RANKL/RANK, all data seem to indicate that TNF-a and IL-1 potentiate osteoclast development via the activation of common second messenger systems, such as NF-/cB activation, and that the effects on OCS require the RANKL/RANK system (Jones et al. 2002). 

FIG. 13 Effect of lycopene on the proliferation of SaOS-2 cells. Compared with respective vehicle control of the same dilution a = p < 0.05, b = p < 0.001, c=p < 0.005 (Kim et al., 2003). (Lycopene II - Effect on osteoblasts The carotenoid lycopene stimulates cell proliferations and alkaline phosphotase activity of SaOS-2 cells. Reprinted from Journal of Medicinal Food. 2003 6, pp. 79-86 by permission of Mary Ann Liebert, Inc., Publishers.)... 

The hormone that opposes the action of PTH is CT. It is produced in the parafollicular cells of the thyroid gland, whereas thyroxine is produced by the follicular cells. Human CT is a 32 amino acid peptide with one disulfide bond. CT is secreted in response to increased serum [Ca2+], especially following a meal. Its role is to prevent hypercalcemia by decreasing the serum [Ca2+]. This is achieved by counteracting the action of PTH on osteoclasts while having no effect on osteoblasts. In addition, CT affects the movement of serum Ca2+ into a labile Ca pool on the bone surface, which then releases Ca back into the circulation when [Ca2+] in serum declines. 

Much clinical and experimental experience has been obtained about the manifestation of bone diseases, especially in renal patients. Many patients with Al-induced bone disease remain asymptomatic. There are two distinct forms of Al bone disease. The most severe form is osteomalacia, with recurrent fractures and resistance to vitamin D therapy. This disease is characterized by an increase of osteoid due to a mineralization defect induced by Al that is localized at a critical site in the bone, i.e., the osteoid calcification front [250]. The adynamic bone disease is another form of Al-related bone disease, characterized by a reduced bone turnover [97]. Al can have a direct negative effect on the bone by deposition at the mineralization front, causing a defective calcification. This is due to the influence of Al on calcium-phosphorus precipitation, crystal formation and crystal growth [251]. There might also be a toxic effect on the proliferation of osteoblasts and on mature osteoblasts with a time- and dose-dependent effect on osteoblast growth and function [143]. 

L3. Lind, M., Growth factor stimulation of bone healing. Effects on osteoblasts, osteomies, and implants fixation. Acta Orthoped. Scand. 283, 2-37 (1998). 

Kim, H.W., Kim, H.E., Salih, V., and Knowles, J.C. (2005) Sol-gel-modified titanium with hydroxyapatite thin films and effect on osteoblast-like cell responses. / Biomed. Mater. Res. A, 74A (3), 294-305. 

Fucodiphlorethol G (Fig. 33.3), a new compoimd isolated from the methanol extract of E. cava, a brown alga, collected offshore in Jeju Island by Ham et al. (2007). By the examination of and NMR data, it was foimd that the structure of the compoimd is similar to that of trimeric phlorotannin triphlorethol-A (Fig. 33.3). Although these studies evidenced that these compoimds can stimulate osteoblast differentiation at various stages, there is no clear demonstration of whether the phlorotannin compound, Fucodiphlorethol G, has direct effect on osteoblast differentiation. 

In another study, Ishaug and co-workers grew enzymatically isolated rat calvarial osteoblasts on different compositions of poly(a-hydroxy ester) films in vitro to evaluate feasibility of cell growth on these polymers and to determine if copolymer composition had any effect on osteoblast adhesion, growth, and phenotype. The compositions tested were 100% PLLA, 75/25 PLGA, 50/50 PLGA, and 100% PGA. Ishaug and co-workers concluded that the osteoblasts attached, proliferated, and maintained their phenotype on all fom compositions. 

Kromka A, Grausova L, B acakova L, Vacik 1, Rezek B, Vanecek M, et al. Semiconducting to metallic-hke boron doping of nanocrystaUine diamond films and its effect on osteoblastic cells. Diam Relat Mater 2010 19 190-5. 

Kim KH, Kwon TY, Kim SY, et al. Preparation and characterization of anodized titanium surfaces and their effect on osteoblast responses. J Oral Implantol 2006 32 8-13. 

Yang YZ, Cavin R, Ong JL. Protein adsorption on titanium surfaces and their effect on osteoblast attachment. J Biomed Mater Res A 2003 67(1) 344—9. 

Zhang YM, et al. Surface analyses of micro-arc oxidized and hydrothermally treated titanium and effect on osteoblast behavior. J Biomed Mater Res A 2004 68(2) 383—91. 

Lim JY, Shaughnessy MC, Zhou Z, Noh H, Vogler EA, Donahue HI. Surface energy effects on osteoblast spatial growth and mineralization. Biomaterials 2008 29 1776-84. 

Benoit DS, Anseth KS. The effect on osteoblast function of colocalized RGD and PHSRN epitopes on PEG surfaces. Biomaterials 2005 26 5209-20. 

Winter, L.C. et al. Intermittent versus continuous stretching effects on osteoblast-like cells in vitro. 

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