Integrin Synthesis and Utilization in Cultured Human Osteoblasts

Pistone, M.; Sanguineti, C.; Federici, A.; Sanguineti, Francesca; Defilippi, Paola; Santolini, F.; Querzé, Germano; Marchisio, Pier Carlo; Manduca, Paola

doi:10.1006/cbir.1996.0062

Cited by 45 publications

(40 citation statements)

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“…RGD peptides also significantly reduced fibronectinmediated attachment, but to a lesser extent than RGD blockade of CBE-mediated attachment (27% for FN vs. 98% for CBE). The modest effect of RGD peptides on fibronectin-mediated attachment is in agreement with several other studies, and suggests that attachment of DU145 cells to fibronectin can occur via non-RGD motifs [20][21][22].…”

Section: Discussionsupporting

confidence: 91%

Effect of bone proteins on human prostate cancer cell lines in vitro

et al. 1998

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BACKGROUND. Despite the high incidence and serious consequences of skeletal metastasis in prostate cancer patients, the mechanisms involved in establishing secondary lesions in bone are not well-understood. In this study, the role of the mineralized bone matrix in the process of skeletal metastasis was evaluated. METHODS. Attachment, migration, and proliferation responses of human prostate cancer cells to a crude bone protein extract (CBE) were studied. LNCaP and DU145 cells were utilized in 24-hr attachment assays. Boyden chamber chemotactic assays and cell proliferation assays utilized DU145 cells. RESULTS. CBE and fibronectin (FN) promoted attachment of DU145 cells, whereas only FN facilitated attachment of LNCaP cells. CBE-mediated adhesion of DU145 cells was reduced by 94% with cycloheximide, by 98% with RGD peptides, and by 94% with an antibody to ␣v␤3. Although DU145 cells migrated toward FN, CBE did not promote migration of DU145 cells. DU145 cells grown in the presence of CBE-containing media demonstrated a significant reduction in cell number by day 4. The antiproliferative effect of CBE was not due to cell toxicity. CONCLUSIONS. In conclusion, results from this study indicate that mineralized bone proteins promote the attachment of DU145 cells in vitro and suggest that bone proteins may play a key role in vivo during the development of metastatic prostate lesions in bone.

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Section: Discussionsupporting

confidence: 91%

Effect of bone proteins on human prostate cancer cell lines in vitro

et al. 1998

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“…Collagen VI is necessary for collagen I production in osteoblast like cells (Harumiya et al, 2002) and interlukin-4-dependent mineralization of human periosteal cells (Ishibashi et al, 1999). Likewise fibronectin, which supports attachment and spreading of hMSC and osteoblasts (Salasznyk et al, 2004b;Ogura et al, 2004;Pistone et al, 1996), is secreted by osteoblasts early in development, and may act to help organize the osteoid matrix by binding to collagen I in mature bone tissue (Nordahl et al, 1995). Damsky and colleagues have demonstrated that osteoblast/fibronectin interactions supply a necessary regulatory signal essential for osteogenic gene expression, with fibronectin possibly playing a role in the recruitment of osteoblast precursor cells (Globus et al, 1995;Moursi et al, 1996;Globus et al, 1998).…”

Section: Discussionmentioning

confidence: 99%

Laminin-5 activates extracellular matrix production and osteogenic gene focusing in human mesenchymal stem cells

et al. 2007

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We recently reported that laminin-5, expressed by human mesenchymal stem cells (hMSC), stimulates osteogenic gene expression in these cells in the absence of any other osteogenic stimulus. Here we employ two dimensional liquid chromatography and tandem mass spectrometry, along with the Database for Annotation, Visualization and Integrated Discovery (DAVID), to obtain a more comprehensive profile of the protein (and hence gene) expression changes occurring during laminin-5-induced osteogenesis of hMSC. Specifically, we compare the protein expression profiles of undifferentiated hMSC, hMSC cultured on laminin-5 (Ln-5 hMSC), and fully differentiated human osteoblasts (hOST) with profiles from hMSC treated with well-established osteogenic stimuli (collagen I, vitronectin, or dexamethazone). We find a marked reduction in the number of proteins (e.g., those involved with calcium signaling and cellular metabolism) expressed in Ln-5 hMSC compared to hMSC, consistent with our previous finding that hOST express far fewer proteins than do their hMSC progenitors, a pattern we call "osteogenic gene focusing." This focused set, which resembles an intermediate stage between hMSC and mature hOST, mirrors the expression profiles of hMSC exposed to established osteogenic stimuli and includes osteogenic extracellular matrix proteins (collagen, vitronectin) and their integrin receptors, calcium signaling proteins, and enzymes involved in lipid metabolism. These results provide direct evidence that laminin-5 alone stimulates global changes in gene/protein expression in hMSC that lead to commitment of these cells to the osteogenic phenotype, and that this commitment correlates with extracellular matrix production.

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“…␣v␤3 is involved in migration on vitronectin whereas ␣v␤5 plays a role in spreading on the same substrate in human monocytes [De Nichilo and Burns 1993]. Moreover, ␣v␤3 and ␣v␤5 have been shown to distribute differentially with ␣v␤3 at the focal adhesion sites whereas ␣v␤5 more diffusely distributed when human osteoblasts are cultured in serum, presumably on vitronectin [Pistone et al, 1996].…”

Section: Discussionmentioning

confidence: 99%

Regulation of ?V?3 and ?V?5 integrins by dexamethasone in normal human osteoblastic cells

et al. 2000

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Long-term administration of pharmacological doses of glucocorticoids inhibits bone formation and results in osteoporosis. Since integrin-mediated cell-matrix interactions are essential for osteoblast function, we hypothesized that the detrimental effect of glucocorticoids on bone derived, at least in part, from decreased integrin-matrix interactions. Because alphavbeta3 and alphavbeta5 integrins can interact with several bone matrix proteins, we analyzed the effects of dexamethasone (Dex) on the expression of these integrins in normal human osteoblastic cells. We found adhesion of these cells to osteopontin and vitronectin to be dependent on alphavbeta3 and alphavbeta5, respectively; this ligand specificity was not altered by Dex. The effects of Dex on the adhesion of human osteoblastic cells to osteopontin and vitronectin were biphasic with an increase after 2 days, followed by a decrease after 8 days of treatment. Consistently, surface alphavbeta3 and alphavbeta5 integrins, which were increased after 2 days of Dex treatment, were decreased after 8 days. Similarly, total cellular alphav, beta3, and beta5 proteins, which were increased by Dex early in the culture, were diminished after 8 days. Metabolic labeling studies indicated that Dex exhibited biphasic regulation on the biosynthesis of alphavbeta5, with stimulation observed during the second day of treatment, followed by inhibition during the 8th day of exposure. By contrast, the biosynthesis of alphavbeta3 was inhibited by Dex on day 1 and remained inhibited on day 8. Analysis of the mRNA indicated that alphav and beta5 levels were increased by Dex during early exposure (1-3 days), followed by inhibition after prolonged exposure (>/=7 days). By contrast, Dex decreased beta3 mRNA level at all the time points analyzed. Consistently, Dex decreased beta3 promoter activity after 1 day and persisted over 8-day period. By contrast, Dex stimulated beta5 promoter activity after 1 or 2 days but had no effect after 8 days. To further evaluate mechanism(s) leading to the decreased integrin expression after prolonged Dex treatment, mRNA stability was analyzed. Dex was found to accelerate the degradation of alphav, beta3 and beta5 mRNA after an 8-day treatment. Thus, the regulation of alphavbeta3 was dependent on transcription and posttranscriptional events whereas the expression of alphavbeta5 was dependent mainly on posttranscriptional events after prolonged Dex treatment. In conclusion, Dex exhibited time-dependent regulation on the expression of alphavbeta3 and alphavbeta5 integrins in normal human osteoblastic cells. Short-term exposure to Dex increased the levels of alphavbeta3 and alphavbeta5 on the surface and cell adhesion to osteopontin and vitronectin whereas long-term exposure to Dex decreased the expression of both integrins and inhibited the cell adhesion to matrix proteins.

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Integrin Synthesis and Utilization in Cultured Human Osteoblasts

Cited by 45 publications

References 0 publications

Effect of bone proteins on human prostate cancer cell lines in vitro

Effect of bone proteins on human prostate cancer cell lines in vitro

Laminin-5 activates extracellular matrix production and osteogenic gene focusing in human mesenchymal stem cells

Regulation of ?V?3 and ?V?5 integrins by dexamethasone in normal human osteoblastic cells

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