Prevention of Glucocorticoid-Induced Apoptosis in Osteocytes and Osteoblasts by Calbindin-D28k

Liu, Yan; Porta, Angela; Peng, Xiaorong; Gengaro, Kristen; Cunningham, Earlene Brown; Li, Hong; Domínguez, L.; Bellido, Teresita; Christakos, Sylvia

doi:10.1359/jbmr.0301242

Cited by 138 publications

(79 citation statements)

References 64 publications

(90 reference statements)

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“…25 Other studies have addressed the effects of Dex on osteogenic cell lines or on primary isolates of osteogenic cells, and often used high Dex concentrations (10 À6 M). 26 One other study showed a nearly linear relationship between rate of apoptosis induction and Dex concentration in a range from 10 À6 to 10 À9 M in murine osteogenic cells, 27 but these cells are farther along the osteogenic lineage than are MSCs. In the present study, higher levels of apoptosis were observed in cultured human bone marrow MSCs at confluence in standard medium, but apoptosis was reduced in Dex supplemented medium.…”

mentioning

confidence: 99%

Dexamethasone inhibition of confluence‐induced apoptosis in human mesenchymal stem cells

Song

Caplan

Dennis

2008

Journal Orthopaedic Research

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Human mesenchymal stem cells (MSCs) have been extensively characterized with respect to their in vitro expansion and differentiation potential, especially with respect to osteogenesis. Dexamethasone (Dex) is a well-known inducer of osteogenic differentiation of MSCs, but little is known about the effect of Dex treatment on apoptosis in MSCs. In this study, apoptosis in MSCs was examined with respect to cell density and Dex supplementation, using DAPI staining and DNA fragmentation ELISA Assay. In MSC cultures initiated at 1.0, 3.0, and 9.0 Â 10 3 cells per cm 2 , it was found that higher MSC density correlated with increased apoptosis and that this apoptotic effect was diminished in cultures containing 100 nM Dex. MSCs and fibroblasts were co-cultured, along with empty insert controls, and assayed for apoptosis by ELISA and DAPI counts to determine if soluble factors accounted for the cell density-related apoptosis. No difference was seen between MSCs cultured with inserts containing either MSCs, fibroblasts, or empty control. To determine cell contact effects, BrdU-labeled MSCs were cultured alone or with unlabeled chondrocytes at 2Â and 8Â the number of MSCs, with and without Dex, and apoptosis levels quantified. The results showed increased apoptosis at greater cell densities, and that the amount of apoptosis was greatly diminished in cultures containing Dex. These results show that apoptosis in MSCs is cell density-related, requires direct cell contact, and that Dex treatment reduces or eliminates this density-related apoptosis. These results may impact how MSCs should be cultured for clinical applications. Keywords: dexamethasone; mesenchymal stem cells; apoptosis Human bone marrow-derived mesenchymal stem cells (MSCs) are a rare population of undifferentiated cells that have the capacity to self-renew and can differentiate into mesodermal phenotypes including osteoblasts, chondrocytes, myocytes, and adipocytes. 1-3 Induction of osteoprogenitor differentiation of MSCs by dexamethasone (Dex) is well known, 4,5 and culture supplementation with Dex at 10 À8 M has been reported to promote osteoprogenitor cell differentiation in marrow stromal cells. 6,7 In addition, Dex is also a component of medium used for differentiation into chondroblasts, myocytes, and adipocytes in vitro. [8][9][10] With respect to Dex effects on apoptosis, the results have often been contradictory, depending upon the cell type being studied. For example, Dex treatment has been shown to induce apoptosis in thymocytes, 11,12 lymphocytes, 13-15 some tumor cells, 16,17 and respiratory epithelium, 18,19 whereas primary cultured hepatocytes, 20 neutrophils, 21,22 and some solid tumors 23,24 show reduced apoptosis after Dex treatment.Interestingly, while Dex has been used extensively with MSCs as an inductive factor for multiple end-stage phenotypes, few studies have assessed the effects of Dex on proliferation and apoptosis. To date, only one other study addressed the issue of Dex effects on MSC apoptosis wherein it was shown that hu...

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confidence: 99%

Dexamethasone inhibition of confluence‐induced apoptosis in human mesenchymal stem cells

Song

Caplan

Dennis

2008

Journal Orthopaedic Research

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“…For the analysis of gene expression, SaM-1 cells were cultured in 6 cm dishes at a density of 1.5ϫ10 5 cells/dish (proliferative stage) for the indicated periods, and then the total RNA was extracted using QIAzol Lysis reagent. The other cell lines were cultured in 10-cm dishes at a density of 1ϫ10 5 cells/dish (proliferative stage) for the indicated periods, and then the total RNA was extracted.…”

Section: Methodsmentioning

confidence: 99%

“…[1][2][3][4][5][6] In addition to their direct effects on osteoblasts, they have also been demonstrated to modify the synthesis of growth factors produced by osteoblastic cells. [7][8][9] These effects lead to the suppression of bone formation, a central feature in the pathogenesis of glucocorticoid induced osteoporosis.…”

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confidence: 99%

Hydrocortisone Inhibits Cellular Proliferation by Downregulating Hepatocyte Growth Factor Synthesis in Human Osteoblasts

Tsunashima

Kondo

Matsuda

et al. 2011

Biological & Pharmaceutical Bulletin

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Glucocorticoids impair the proliferation, differentiation, and function of osteoblasts and induce apoptosis in mature osteoblasts. [1][2][3][4][5][6] In addition to their direct effects on osteoblasts, they have also been demonstrated to modify the synthesis of growth factors produced by osteoblastic cells. [7][8][9] These effects lead to the suppression of bone formation, a central feature in the pathogenesis of glucocorticoid induced osteoporosis. Hepatocyte growth factor (HGF), which was initially thought to be of mesodermal origin, and its receptor are expressed in osteoblasts and osteoclasts. [10][11][12] Previous studies have shown the inhibitory effects of glucocorticoids on HGF mRNA expression in rat calvarial osteoblasts 13) and human osteoblast-like cells, 14) and the stimulatory effects of HGF on thymidine incorporation in osteoblasts.11) These findings led us to investigate whether the effects of glucocorticoids on cellular proliferation are mediated by HGF in human osteoblastic cells. In this study, using osteoblastic cells (SaM-1) and osteogenic sarcoma cells (SaOS-2, HOS, and MG-63), we demonstrate that HGF functions in an autocrine and/or paracrine manner, resulting in mitogenesis. Furthermore, we show that the inhibitory effects of glucocorticoid on the proliferation of human osteoblastic cells can probably be explained by the concomitant glucocorticoidinduced inhibition of HGF production. MATERIALS AND METHODS MaterialsHydrocortisone was obtained from Sigma (St. Louis, MO, U.S.A.), and recombinant human HGF protein and a human HGF enzyme-linked immunosorbent assay (ELISA) system were obtained from R&D systems (Minneapolis, MN, U.S.A.). The bromodeoxyuridine (BrdU) cell proliferation ELISA was from Roche (Penzberg, Germany). QIAzol lysis reagent was obtained from Qiagen (Hilden,was obtained from CalBiochem (San Diego, CA, U.S.A.). Normal human osteoblasts (SaM-1 cells) were kindly provided by Dr. Koshihara (Tokyo Metropolitan Institute of Gerontology), who prepared them from an explant of ulnar periosteum obtained from a 20-year-old male patient undergoing curative surgery who gave his informed consent for its experimental use. SaM-1 cells have a mitotic life span of 34 population doubling levels (PDL), 15) and we used them at 23-24 PDL in our experiments. HOS and SaOS-2 human osteogenic sarcoma cells were obtained from the RIKEN Cell Bank (Tsukuba, Japan). MG-63 human osteogenic sarcoma cells were from the American Type Culture Collection (Rockville, MD, U.S.A.). Alpha-modified minimum essential medium (a-MEM) was purchased from Gibco BRL (Grand Island, NY, U.S.A.), and fetal calf serum (FCS) was obtained from Cell Culture Laboratories (Cleveland, OH, U.S.A.) and Irvine Scientific (Santa Ana, California, U.S.A.). All other chemicals used were of reagent grade.Cell Culture The medium used for all cell lines was a-MEM containing 10% fetal calf serum (FCS), and the cells were incubated in a humidified incubator at 37°C in 95% air and 5% CO 2 . In an analysis of proliferation, SaM-1 cells were seed...

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“…[31][32][33] The decrease in osteoblast differentiation includes induction of adipogenetic transcription factors (PPARγ) and suppression of Wnt protein signalling; [34][35][36][37] the increase of osteoblast and osteocyte apoptosis is associated with caspase 3 activation. 38 Moreover, the osteoblast function is decreased through the antianabolic effects of GCs, such as decrease in GH, IGF1 and IGFBP 3-4-5 . In contrast, GCs increase IGFBP 6 transcription thus decreasing IGF2, another local regulator of osteoblast function.…”

Section: Bone Effects Of Gcsmentioning

confidence: 99%

Glucocorticoid-Induced Osteoporosis

2002

Frontiers of Hormone Research

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Corticosteroid-induced osteoporosis is the most common form of secondary osteoporosis and the first cause in young people. Bone loss and increased rate of fractures occur early after the initiation of corticosteroid therapy, and are then related to dosage and treatment duration. The increase in fracture risk is not fully assessed by bone mineral density measurements, as it is also related to alteration of bone quality and increased risk of falls. In patients with rheumatoid arthritis, a treat-to-target strategy focusing on low disease activity including through the use of low dose of prednisone, is a key determinant of bone loss prevention. Bone loss magnitude is variable and there is no clearly identified predictor of the individual risk of fracture. Prevention or treatment of osteoporosis should be considered in all patients who receive prednisone. Bisphosphonates and the anabolic agent parathyroid hormone (1-34) have shown their efficacy in the treatment of corticosteroid-induced osteoporosis. Recent international guidelines are available and should guide management of corticosteroid-induced osteoporosis, which remains under-diagnosed and undertreated. Duration of antiosteoporotic treatment should be discussed at the individual level, depending on the subject's characteristics and on the underlying inflammation evolution.

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Prevention of Glucocorticoid-Induced Apoptosis in Osteocytes and Osteoblasts by Calbindin-D28k

Cited by 138 publications

References 64 publications

Dexamethasone inhibition of confluence‐induced apoptosis in human mesenchymal stem cells

Dexamethasone inhibition of confluence‐induced apoptosis in human mesenchymal stem cells

Hydrocortisone Inhibits Cellular Proliferation by Downregulating Hepatocyte Growth Factor Synthesis in Human Osteoblasts

Glucocorticoid-Induced Osteoporosis

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