scholarly journals Growth retardation induced by dexamethasone is associated with increased apoptosis of the growth plate chondrocytes

2003 ◽  
Vol 176 (3) ◽  
pp. 331-337 ◽  
Author(s):  
D Chrysis ◽  
EM Ritzen ◽  
L Savendahl
Keyword(s):  
Growth Plate ◽  
Growth Retardation ◽  
Caspase 3 ◽  
Male Rats ◽  
Apoptotic Cells ◽  
Growth Plate Chondrocytes ◽  
Glucocorticoid Treatment ◽  
Local Mechanism ◽  
Apoptotic Proteins ◽  
Multicellular Organisms

Glucocorticoids cause significant growth retardation in mammals and humans and decreased proliferation of chondrocytes has been considered as the main local mechanism. Death by apoptosis is an important regulator of homeostasis in multicellular organisms. Here we chose to study the role of apoptosis in growth retardation caused by glucocorticoid treatment. We treated 7-week-old male rats with dexamethasone (5 mg/kg/day) for 7 days. Apoptosis was studied in tibiae growth plates by the TUNEL method. Immunoreactivity for parathyroid hormone-related peptide (PTHrP), caspase-3, and the anti-apoptotic proteins Bcl-2 and Bcl-x was also studied. Apoptosis was mainly localized in terminal hypertropic chondrocytes (THCs) in both control and dexamethasone-treated animals. Dexamethasone caused an increase in apoptosis which was fourfold in THCs (2.45+/-0.12 vs 0.62+/-0.09 apoptotic cells/mm growth plate, P<0.001), and 18-fold in proliferative chondrocytes (0.18+/-0.04 vs 0.01+/-0.007 apoptotic cells/mm growth plate, P<0.001). Increased apoptosis after dexamethasone treatment was accompanied by increased immunoreactivity for caspase-3 and decreased immunoreactivity for the anti-apoptotic proteins Bcl-2 and Bcl-x, which further supports our apoptosis results. Dexamethasone also decreased the immunoreactivity for PTHrP, suggesting a role in the mechanism by which glucocorticoids induce apoptosis in the growth plate. We conclude that apoptosis is one mechanism involved in growth retardation induced by glucocorticoids. Premature loss of resting/proliferative chondrocytes by apoptosis could contribute to incomplete catch-up seen after prolonged glucocorticoid treatment.

scholarly journals Valproic Acid Impacts the Growth of Growth Plate Chondrocytes

2020 ◽  
Vol 17 (10) ◽  
pp. 3675
Author(s):  
Hueng-Chuen Fan ◽  
Shih-Yu Wang ◽  
Yi-Jen Peng ◽  
Herng-Sheng Lee
Keyword(s):  
Valproic Acid ◽  
Short Stature ◽  
Growth Plate ◽  
Caspase 3 ◽  
Skeletal Growth ◽  
Growth Plate Chondrocytes ◽  
Protein Levels ◽  
Rat Growth ◽  
Cox 2 ◽  
Bone Abnormalities

A range of bone abnormalities including short stature have been reported to be associated with the use of antiepileptic drugs (AEDs) in children. Exactly how AEDs impact skeletal growth, however, is not clear. In the present study, rat growth plate chondrocytes were cultured to study the effects of AEDs, including valproic acid (VPA), oxcarbazepine (OXA), levetiracetam (LEV), lamotrigine (LTG), and topiramate (TPM) on the skeletal growth. VPA markedly reduced the number of chondrocytes by apoptosiswhile other AEDs had no effect. The apoptosis associated noncleaved and cleaved caspase 3, and caspases were increased by exposure to VPA, which up-regulated cyclooxygenase 2 (COX-2) mRNA and protein levels likely through histone acetylation. The COX-2 inhibitor NS-398 attenuated the effects of VPA up-regulating COX-2 expression and decreased VPA-induced caspase 3 expression. The use of VPA in children should be closely monitored or replaced, where appropriate, by AEDs which do not apparently affect the growth plate chondrocytes.

scholarly journals mir-374-5p, mir-379-5p, and mir-503-5p Regulate Proliferation and Hypertrophic Differentiation of Growth Plate Chondrocytes in Male Rats

Endocrinology ◽  
2018 ◽  
Vol 159 (3) ◽  
pp. 1469-1478 ◽  
Author(s):  
Youn Hee Jee ◽  
Jinhee Wang ◽  
Shanna Yue ◽  
Melissa Jennings ◽  
Samuel J Clokie ◽  
...  
Keyword(s):  
Growth Plate ◽  
Male Rats ◽  
Growth Plate Chondrocytes

scholarly journals Apoptosis of Growth Plate Chondrocytes Occurs through a Mitochondrial Pathway

2007 ◽  
Vol 77 (1) ◽  
pp. 129-134 ◽  
Author(s):  
Cristina C. Teixeira ◽  
Aida P. Padron Costas ◽  
Yelena Nemelivsky
Keyword(s):  
Cytochrome C ◽  
Growth Plate ◽  
Caspase 3 ◽  
Mitochondrial Pathway ◽  
Chondrocyte Apoptosis ◽  
Cytochrome C Release ◽  
Growth Plate Chondrocytes ◽  
Chondrocyte Viability ◽  
Induced Apoptosis ◽  
Free Media

Abstract Objective: To determine the role of mitochondria in chondrocyte apoptosis induced by inorganic phosphate (Pi). Materials and Methods: Chondrocytes isolated from the growth plates of chick embryo tibia were treated with Pi in serum-free media; chondrocyte viability, mitochondrial membrane potential, cytochrome c release from mitochondria, caspase 3 activity, endonuclease activity, and DNA fragmentation were investigated. Results: Exposure to Pi for 24 hours induced apoptosis in growth plate chondrocytes through a pathway that involved loss of mitochondrial function, release of cytochrome c into the cytoplasm, increases in caspase 3 and endonuclease activities, and fragmentation of DNA. Conclusions: This study suggests that mitochondria are important players in Pi-induced apoptosis.

scholarly journals 17β-Estradiol Regulates Rat Growth Plate Chondrocyte Apoptosis Through a Mitochondrial Pathway Not Involving Nitric Oxide or MAPKs

Endocrinology ◽  
2011 ◽  
Vol 152 (1) ◽  
pp. 82-92 ◽  
Author(s):  
M. Zhong ◽  
D. H. Carney ◽  
B. D. Boyan ◽  
Z. Schwartz
Keyword(s):  
Nitric Oxide ◽  
Growth Plate ◽  
Caspase 3 ◽  
Growth Zone ◽  
Mapk Signaling ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Dependent Manner ◽  
Growth Plate Chondrocytes ◽  
Bax Protein ◽  
17Β Estradiol

Abstract Estrogens cause growth plate closure in both males and females, by decreasing proliferation and inducing apoptosis of postproliferative growth plate chondrocytes. In vitro studies using 17β-estradiol (E2) conjugated to bovine serum albumin (E2-BSA) show that rat costochondral growth plate resting zone chondrocytes also respond to E2. Moreover, they are regulated by E2-BSA via a protein kinase C and ERK MAPK signaling pathway that is functional only in female cells. To better understand how E2 regulates apoptosis of growth plate chondrocytes, rat resting zone chondrocytes cells were treated with E2 or E2-BSA. E2 caused apoptosis in male and female resting zone and growth zone chondrocytes in a dose-dependent manner, based on elevated DNA fragmentation, terminal deoxynucleotidyl transferase dUTP nick end labeling staining and caspase-3 activation. E2 also up-regulated p53 and Bax protein (Bcl-2-associated X protein) levels and induced release of cytochrome C from the mitochondria, indicating a mitochondrial apoptotic pathway. The apoptotic effect of E2 did not involve elevated nitric oxide production or MAPKs. It was reduced by ICI 182780, which is an estrogen receptor (ER) antagonist and blocked by antibodies to Erα36, a membrane-associated ER. E2-BSA reduced cell viability and increased caspase-3 activity; ICI 182780 had no effect, but anti-ERα36 antibodies blocked the effect. The results indicate that estrogen is able to directly affect the cell population kinetics of growth plate chondrocytes by regulating apoptosis, as well as proliferation and differentiation in both resting zone and growth zone cells. They also have provided further information about the physiological functions of estrogen on longitudinal bone growth.

scholarly journals Dexamethasone-induced growth inhibition of porcine growth plate chondrocytes is accompanied by changes in levels of IGF axis components

2002 ◽  
Vol 174 (2) ◽  
pp. 343-352 ◽  
Author(s):  
JJ Smink ◽  
JA Koedam ◽  
JG Koster ◽  
SC van Buul-Offers
Keyword(s):  
Growth Inhibition ◽  
Growth Plate ◽  
Growth Retardation ◽  
Culture Conditions ◽  
Type I ◽  
Mrna Levels ◽  
Growth Plate Chondrocytes ◽  
Type I Igf Receptor ◽  
Igf I ◽  
Igf Receptor

High (pharmacological) doses of glucocorticoids inhibit the proliferation of growth plate chondrocytes, which leads to one of the side-effects of these steroids, namely suppression of longitudinal growth. Growth inhibition by glucocorticoids is thought to be mediated in part by impaired action of components of the IGF axis, which are important for chondrocyte regulation and hence for longitudinal growth. The aim of the present study was to determine whether glucocorticoid-induced growth retardation involves changes in IGF axis components. Chondrocytes were isolated from epiphyseal growth plates of neonatal piglets and treated with pharmacological doses of dexamethasone (DXM) for 24 h to study glucocorticoid-induced growth retardation. Under IGF-I-supplemented (10 nM) culture conditions, IGF-binding proteins (IGFBPs)-2, -4 and -5 were secreted by the growth plate chondrocytes and IGFBP-2 protein and mRNA levels were decreased by the DXM treatment, whereas IGFBP-4 and -5 were not affected. Proliferation of the chondrocytes, as measured by [(3)H]thymidine incorporation, was 3.5-fold higher in serum-supplemented medium in contrast to IGF-I-supplemented (10 nM) medium. In the presence of serum, DNA synthesis was significantly inhibited by 50-63% when treated with 100 nM DXM, which was prevented by the glucocorticoid-receptor antagonist Org34116. mRNA levels of IGF axis components were determined using Northern blot analysis. IGFBP-2 to -6 were expressed in the chondrocytes, IGFBP-1 was absent and both IGF-I and IGF-II, and the type I and type II IGF receptors were expressed. Treatment with DXM (100 nM) resulted in a 2-fold increase in mRNA levels of both IGFBP-5 and the type I IGF receptor, whereas IGFBP-2 mRNA levels decreased by 55%, in concert with the decrease in protein level observed under IGF-I-supplemented culture conditions. The changes in mRNA levels due to the DXM treatment were prevented by the glucocorticoid receptor antagonist. Our data show that exposure to pharmacological doses of DXM results in inhibition of proliferation and changes in components of the IGF axis, IGFBP-2 and -5 and the type I IGF receptor, suggesting a role for these components in glucocorticoid-induced growth retardation at the local level of the growth plate.

Dexamethasone-induced expression of the glucocorticoid response gene lipocalin 2 in chondrocytes

2008 ◽  
Vol 294 (6) ◽  
pp. E1023-E1034 ◽  
Author(s):  
H. C. Owen ◽  
S. J. Roberts ◽  
S. F. Ahmed ◽  
C. Farquharson
Keyword(s):  
Growth Plate ◽  
Growth Retardation ◽  
Collagen Type ◽  
Tissue Growth ◽  
Lipocalin 2 ◽  
Growth Plate Chondrocytes ◽  
Ru 486 ◽  
Hypertrophic Growth ◽  
Glucocorticoid Response ◽  
Upregulated Genes

Glucocorticoids (GC) are commonly used anti-inflammatory drugs, but long-term use can result in marked growth retardation in children due to their actions on growth plate chondrocytes. To gain an insight into the mechanisms involved in GC-induced growth retardation, we performed Affymetrix microarray analysis of the murine chondrogenic cell line ATDC5, incubated with 10−6 M dexamethasone (Dex) for 24 h. Downregulated genes included secreted frizzled-related protein and IGF-I, and upregulated genes included serum/GC-regulated kinase, connective-tissue growth factor, and lipocalin 2. Lipocalin 2 expression increased 40-fold after 24-h Dex treatment. Expression increased further after 48-h (75-fold) and 96-h (84-fold) Dex treatment, and this response was Dex concentration dependent. Lipocalin 2 was immunolocalized to both proliferating and hypertrophic growth plate zones, and its expression was increased by Dex in primary chondrocytes at 6 h (3-fold, P < 0.05). The lipocalin 2 response was blocked by the GC-receptor antagonist RU-486 and was increased further by the protein synthesis blocker cycloheximide. Proliferation in lipocalin 2-overexpressing cells was less than in control cells (49%, P < 0.05), and overexpression caused an increase in collagen type X expression (4-fold, P < 0.05). The effects of lipocalin 2 overexpression on chondrocyte proliferation (64%, P < 0.05) and collagen type X expression (8-fold, P < 0.05) were further exacerbated with the addition of 10−6 M Dex. This synergistic effect may be explained by a further increase in lipocalin 2 expression with Dex treatment of transfected cells (45%, P < 0.05). These results suggest that lipocalin 2 may mediate Dex effects on chondrocytes and provides a potential novel mechanism for GC-induced growth retardation.

scholarly journals Cartilage Ablation of Sirt1 Causes Inhibition of Growth Plate Chondrogenesis by Hyperactivation of mTORC1 Signaling

Endocrinology ◽  
2019 ◽  
Vol 160 (12) ◽  
pp. 3001-3017 ◽  
Author(s):  
Xinxin Jin ◽  
Xiaomin Kang ◽  
Liting Zhao ◽  
Mao Xu ◽  
Tianping Xie ◽  
...  
Keyword(s):  
Growth Plate ◽  
Growth Retardation ◽  
Bone Growth ◽  
Bone Development ◽  
Conditional Knockout ◽  
Negative Regulator ◽  
Sirtuin 1 ◽  
Growth Plate Chondrocytes ◽  
Mtorc1 Signaling

Abstract A growing body of evidence implies a pivotal role of sirtuin-1 (Sirt1) in chondrocyte function and homeostasis; however, its underlying mechanisms mediating chondrogenesis, which is an essential process for physiological skeletal growth, are still poorly understood. In the current study, we generated TamCartSirt1−/− [Sirt1 conditional knockout (cKO)] mice to explore the role of Sirt1 during postnatal endochondral ossification. Compared with control mice, cKO mice exhibited growth retardation associated with inhibited chondrocyte proliferation and hypertrophy, as well as activated apoptosis. These effects were regulated by hyperactivation of mammalian target of rapamycin complex 1 (mTORC1) signaling, and thereby inhibition of autophagy and induction of endoplasmic reticulum stress in growth plate chondrocytes. IP injection of the mTORC1 inhibitor rapamycin to mice with Sirt1 deletion partially neutralized such inhibitory effects of Sirt1 ablation on longitudinal bone growth, indicating the causative link between SIRT1 and mTORC1 signaling in the growth plate. Mechanistically, SIRT1 interacted with tuberous sclerosis complex 2 (TSC2), a key upstream negative regulator of mTORC1 signaling, and loss of Sirt1 inhibited TSC2 expression, resulting in hyperactivated mTORC1 signaling in chondrocytes. In conclusion, our findings suggest that loss of Sirt1 may trigger mTORC1 signaling in growth plate chondrocytes and contributes to growth retardation, thus indicating that SIRT1 is an important regulator during chondrogenesis and providing new insights into the clinical potential of SIRT1 in bone development.

scholarly journals Mathematical Assessment of Results of Investigation of the BCL-2 and Caspase-3 Protein Expression under the Influence of nanobiocomposites of Silver on natural and Synthetic Matrixes

2019 ◽  
Vol 3 (6) ◽  
pp. 150-155
Author(s):  
M. A. Novikov ◽  
E. A. Titov ◽  
V. A. Vokina ◽  
L. M. Sosedova
Keyword(s):  
Silver Nanoparticles ◽  
Discriminant Analysis ◽  
Caspase 3 ◽  
Early Period ◽  
Feature Space ◽  
Male Rats ◽  
Apoptotic Proteins ◽  
Comparison Of The Results ◽  
Two Stages

The aim was to assess the effect of silver nanoparticles on the expression of proand anti-apoptotic proteins caspase-3 and bcl-2 by discriminant analysis.Materials and methods. 120 sexually mature outbred male rats were divided into 8 groups (pure arabinogalactan (AG), pure poly-1-vinyl-1,2,4-triazol (PVT), nanobiocomposites on the AG and PVT matrix at a dose of 100 and 500 μg/kg. The administration was done orally for 9 days. The experimental study was carried out in two stages. The first stage included the examination of animals immediately after the end of the exposure of the studied substances (early period), the second stage – a survey 6 months after the end of the exposure (the long-term period).Results. The most distinguished groups were the groups that were administered silver nanoparticles on the AG matrix at a dose of 100 and 500 μg/kg.Conclusion. Comparison of the results of the discriminant analysis allowed to fully determine the effect of silver nanoparticles on the expression of proand anti-apoptotic proteins caspase-3 and bcl-2 when they were introduced on the AG and PVT matrix. In the AG groups and nanobiocomposites based on it, in the feature space, it was shown that the most remote by differentiating characteristics are the groups nAG100 and nAG500. In nanocomposites on the PVT matrix, a group of animals differing in differentiating features has not been identified.

scholarly journals Gradients in bone morphogenetic protein-related gene expression across the growth plate

2007 ◽  
Vol 193 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Ola Nilsson ◽  
Elizabeth A Parker ◽  
Anita Hegde ◽  
Michael Chau ◽  
Kevin M Barnes ◽  
...  
Keyword(s):  
Growth Plate ◽  
Bone Morphogenetic Proteins ◽  
Bmp Signaling ◽  
Male Rats ◽  
Quiescent State ◽  
Growth Plate Chondrocytes ◽  
Proliferative Zone ◽  
Morphogenetic Protein ◽  
Proliferation And Differentiation ◽  
Signaling Inhibitors

In the growth plate, stem-like cells in the resting zone differentiate into rapidly dividing chondrocytes of the proliferative zone and then terminally differentiate into the non-dividing chondrocytes of the hypertrophic zone. To explore the molecular switches responsible for this two-step differentiation program, we developed a microdissection method to isolate RNA from the resting (RZ), proliferative (PZ), and hypertrophic zones (HZ) of 7-day-old male rats. Expression of approximately 29 000 genes was analyzed by microarray and selected genes verified by real-time PCR. The analysis identified genes whose expression changed dramatically during the differentiation program, including multiple genes functionally related to bone morphogenetic proteins (BMPs). BMP-2 and BMP-6 were upregulated in HZ compared with RZ and PZ (30-fold each, P < 0.01 and 0.001 respectively). In contrast, BMP signaling inhibitors were expressed early in the differentiation pathway; BMP-3 and gremlin were differentially expressed in RZ (100- and 80-fold, compared with PZ, P < 0.001 and 0.005 respectively) and growth differentiation factor (GDF)-10 in PZ (160-fold compared with HZ, P < 0.001). Our findings suggest a BMP signaling gradient across the growth plate, which is established by differential expression of multiple BMPs and BMP inhibitors in specific zones. Since BMPs can stimulate both proliferation and hypertrophic differentiation of growth plate chondrocytes, these findings suggest that low levels of BMP signaling in the resting zone may help maintain these cells in a quiescent state. In the lower RZ, greater BMP signaling may help induce differentiation to proliferative chondrocytes. Farther down the growth plate, even greater BMP signaling may help induce hypertrophic differentiation. Thus, BMP signaling gradients may be a key mechanism responsible for spatial regulation of chondrocyte proliferation and differentiation in growth plate cartilage.

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