Regulation of insulin-like growth factors I and II and their binding proteins in human bone marrow stromal cells by dexamethasone

Cheng, Su‐Li; Zhang, Shufang; Mohan, Subburaman; Lecanda, Fernando; Fausto, Aurora; Hunt, Ann H.; Canalis, Ernesto; Avioli, Louis V.

doi:10.1002/(sici)1097-4644(19981201)71:3<449::aid-jcb13>3.0.co;2-d

Cited by 55 publications

(36 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…My finding that Dex markedly inhibited IGF-I expression is consistent with the known inhibitory effect of Dex on IGF-I expression in several osteoblastic cell models. For example, Dex was observed to inhibit IGF-I expression in cultured rat bone cells [7] and human bone marrow stromal cell cultures [8], and also to have an adverse effect on IGF-I-mediated signaling of osteoblast differentiation in hMSC cells [16]. In addition, by contrast to the anabolic effect of IGF-I on bone, in vivo exposure to excessive glucocorticoids results in rapid bone loss with an increase in osteoporotic fracture risk [17].…”

Section: Discussioncontrasting

confidence: 86%

“…The effects of GCs have been studied on other members of the IGF/IGFBP system. For example, it has been reported that Dex can induce IGF-II at both the mRNA and protein levels in human mesenchymal stem cells (hMSC) during osteoblast differentiation [8], and the expression of IGFBP-2 was shown to be regulated by Dex in osteoblastic cell cultures in a positive [29] or negative manner [30]. However, I could not detect any changes in the mRNA expression levels of IGF-II or IGFBP2 in NIH3T3 cells treated either with Dex alone or in combination with 1,25(OH) 2 D 3 .…”

Section: Discussionmentioning

confidence: 90%

“…In vitro studies indicate that the effects of GCs on osteoblast differentiation vary with the stage of cell growth and differentiation. GCs were reported to be crucial for the induction of osteoblast differentiation in both human and rat bone marrow stromal cells [6,8], while they decreased the rate of cell proliferation of mature osteoblasts and osteocytes by inducing apoptosis as well as inhibiting the cell cycle [19]. It has been reported that the administration of Dex alone is not enough to induce osteoblast differentiation in NIH3T3, but it can rather inhibit its cell proliferation [20].…”

Section: Discussionmentioning

confidence: 99%

“…In this context, the inhibitory effect of Dex on cell growth and IGF-I synthesis has been reported for murine osteoblastic cells during their differentiation [22]. My finding that Dex markedly stimulates IGFBP-5 mRNA expression during the osteoblast differentiation of NIH3T3 contrasts with the reported inhibitory effect of Dex on the expression of IGFBP-5 in human osteoblastic-like cells [23], and cultured cells from human rib marrow [8]. On the other hand, in non-osteoblastic cell types, the regulatory effects of Dex on IGFBP-5 were controversial.…”

Section: Discussionmentioning

confidence: 99%

“…GCs were among the first agents identified to mediate osteogenic differentiation in vitro, where their effect was associated with the regulation of the IGF-system [6]. GCs were shown to suppress the production of IGF-I and -II at the mRNA and protein levels in osteoblastic cell cultures [7] and to have a major effect on the modulation of mRNA expression and the secretion levels of IGFBPs, including IGFBP-3, -4, and -5 [8]. 1,25(OH) 2 D 3 plays an important role in maintaining skeletal integrity and osteoblast functions.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Osteoblast differentiation of NIH3T3 fibroblasts is associated with changes in the IGF-I/IGFBP expression pattern

Abdallah

2006

Cellular and Molecular Biology Letters

View full text Add to dashboard Cite

Abbreviations used: ALP -alkaline phosphatase; BMP-2 -Bone morphogenetic protein-2; Cbfa1/Runx2 -Core binding factor, runt domain, alfa subunit 1; Dex -Dexamethasone; GCglucocorticoid; IGFBPs -insulin like growth factor binding proteins; IGFs -insulin like growth factors; MSC -mesenchymal stem cells; OC -osteocalcin; OPN -osteopontein; RT -reverse transcriptase. Short communication OSTEOBLAST DIFFERENTIATION OF NIH3T3 FIBROBLASTS IS ASSOCIATED WITH CHANGES IN THE IGF-I/IGFBP EXPRESSION PATTERNBASEM M. ABDALLAH* Department of Biochemistry, Faculty of Science, Helwan University, Cairo, Egypt Abstract: Insulin-like growth factors (IGFs) and IGF-binding proteins (IGFBPs) are essential regulators for osteoblast proliferation and differentiation. It has been reported that Dexamethasone (Dex), an active glucocorticoid (GC) analogue, synergizes the stimulatory effect of 1,25-dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ) on osteoblast differentiation in the mouse fibroblastic cell line NIH3T3. I investigated whether this stimulatory effect is associated with changes in the expression pattern of the IGF/IGFBP system. Quantitative realtime PCR technology was used to quantify the gene expression levels of the IGF-system during osteoblast differentiation and in response to 1,25(OH) 2 D 3 or Dex alone under serum-containing and serum-free culture conditions. Interestingly, NIH3T3 was shown to express high mRNA levels of IGF-I, IGF-II and IGFBP-5, and low levels of both IGFBP-2 and -6. During osteoblast differentiation (days 6-12), IGF-I mRNA was repressed by more than 60%, while the transcript of IGFBP-5 was markedly up-regulated, by more than 50-fold. Similarly, treatment with Dex alone resulted in a dose-and time-dependent increase in the expression of IGFBP-5 and a decrease in IGF-I mRNA. Treatment with 1,25(OH) 2 D 3 alone increased the mRNA levels of IGF-I and IGFBP-6 by around 4-and 7-fold, respectively, in a dose-and time-dependent manner. In conclusion, my data demonstrated that osteoblast differentiation of NIH3T3 is associated with changes in the expression pattern of IGFs/IGFBPs,

show abstract

Section: Discussioncontrasting

confidence: 86%

Section: Discussionmentioning

confidence: 90%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Osteoblast differentiation of NIH3T3 fibroblasts is associated with changes in the IGF-I/IGFBP expression pattern

Abdallah

2006

Cellular and Molecular Biology Letters

View full text Add to dashboard Cite

show abstract

Insulin-like growth factor binding proteins in femoral and vertebral bone marrow stromal cells: Expression and regulation by thyroid hormone and dexamethasone

et al. 2001

View full text Add to dashboard Cite

Insulin-like growth factor (IGF)-I is an important regulator of bone metabolism. Clinical observations suggest that different anatomic sites within the adult skeleton respond differently to hormonal and therapeutic treatment, and recent studies on bone marrow stromal cells in culture show that there are skeletal site-dependent differences in the gene expression of IGF-I. The actions of IGF-I and -II on bone cells are known to be modulated by the IGF binding proteins (IGFBP)-1 through -6 and the Type I and Type II IGF receptors. Therefore, we compared the expression of IGFBP-1 through -6 in adult female rat bone marrow stromal cell cultures derived from two separate skeletal sites: vertebrae and femurs. The cultures were maintained simultaneously under conditions that support osteoblast differentiation from osteoprogenitors present in the femoral and vertebral marrow cell populations. We also addressed whether IGFBP messenger RNA levels are regulated by thyroid hormone (T(3)) and dexamethasone (dex) treatment in femoral vs. vertebral marrow stromal cells in vitro, since steroid hormones play an important role in skeletal function. Northern blot analyses revealed that there are distinct skeletal site differences in the gene expression of IGFBPs. The vertebral marrow cultures express IGFBP-2 through -6 mRNAs, with IGFBP-2, IGFBP-4, and IGFBP-6 mRNAs predominating. The femoral marrow stromal cell cultures express only IGFBP-4 and IGFBP-6. Importantly, vertebral marrow cultures have much higher IGFBP mRNA steady-state levels than femoral cultures for all the detected IGFBP transcripts. IGFBP-1 is not detected in either femoral or vertebral cultures. In addition to a skeletal site difference, we show that T(3) and dex regulate the expression of specific IGFBP mRNAs. T(3) treatment also upregulates IGF-I protein secretion by vertebral marrow stromal cell cultures. Interestingly, the type I receptor for IGF-I was expressed equivalently in cultures from the two skeletal sites. These findings have important implications for the anatomical site specificities of hormonal responses that are noted in the skeleton.

show abstract

Shielding and dielectric properties of sulfonic acid‐doped π‐conjugated polymer in 8.2–12.4 GHz frequency range

Ohlan¹,

Singh²,

Dhawan³

2009

J of Applied Polymer Sci

View full text Add to dashboard Cite

This article deals with dielectric and electromagnetic interference shielding properties of the polyaniline doped with dodecyl benzene sulfonic acid (DBSA) synthesized by microemulsion polymerization of aniline in aqueous solution of DBSA. Dielectric constant and shielding effectiveness due to absorption (SE A ) were calculated using S-parameter obtained from the vector network analyzer in 8.2-12.4 GHz frequency range. Maximum SE A of 26 dB (>99%) was achieved for polymer sample. The real part e 0 of complex permittivity shows small variation, whereas the imaginary part e 00 is found to decrease with the increase in frequency. Different formulations have been performed to see the effect of monomer to dopant ratio on intrinsic properties of polyaniline. Further characterization of polymer was carried out by UV-visible and thermal gravimetric analysis, whereas the conductivity measurements were carried out by the four-probe method.

show abstract

Regulation of insulin-like growth factors I and II and their binding proteins in human bone marrow stromal cells by dexamethasone

Cited by 55 publications

References 51 publications

Osteoblast differentiation of NIH3T3 fibroblasts is associated with changes in the IGF-I/IGFBP expression pattern

Osteoblast differentiation of NIH3T3 fibroblasts is associated with changes in the IGF-I/IGFBP expression pattern

Insulin-like growth factor binding proteins in femoral and vertebral bone marrow stromal cells: Expression and regulation by thyroid hormone and dexamethasone

Shielding and dielectric properties of sulfonic acid‐doped π‐conjugated polymer in 8.2–12.4 GHz frequency range

Contact Info

Product

Resources

About