Pathogenesis of glucocorticoid-induced osteoporosis based on label-free mass proteomics / 中国骨伤

OBJECTIVE@#To explore pathogenesis of glucocortocoid-induced osteoporosis(GIOP) based on label-free mass proteomics.@*METHODS@#Twevle female Sprague-Dawley(SD) rats were randomly divided into two groups, named as sham group and GIOP group. After one-week adaptive feeding, the rats of GIOP group were administered with dexamethasone via intramuscular injection according to 2.5 mg/kg weighting, while the rats of sham group were administered with the same amount of saline, twice a week. The tibias of each group were collected after 8-week modeling and made pathological sections to confirm the success of modeling. Three samples of each group were picked up to perform label-free mass proteomics. After quality control, differentially expressed proteins were identified according to qualitative and quantitative analyses. Then gene ontology(GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis, cluster analysis as well as protein-protein interaction analysis were performed using bioinformatics analysis.@*RESULTS@#Compared with sham group, the structure of bone trabecular in GIOP group showed abnormal arrangement, uneven distribution and obvious fragmentation, which could demonstrate successful modeling. A total of 47 differentially expressed proteins (DEPs) were identified including 20 up-regulated and 27 down-regulated proteins. The expression of protein nucleophosmin 1(NPM1), adipocyte plasma membrane associated protein (APMAP), cytochromec oxidase subunit 6A1 (COX6A1) and tartrate-resistant acid phosphatase (ACP5) showed a significant difference between two groups. KEGG results showed DEPs were enriched on metabolism-related pathways, immune-related pathways and AMP-activated kinase (AMPK) signaling pathway.@*CONCLUSION@#Protein NPM1, APMAP, COX6A1 and ACP5 showed a close relationship with pathogenesis of GIOP, which could serve as potential biomarkers of GIOP. AMPK signaling pathway played an important role in the occurrence and development of GIOP, which could be regarded as potential signaling pathway to treatment GIOP.

Mechanism of Artemisia annua L. in GIOP with kidney-yin deficiency based on network pharmacology / 药学实践杂志

Objective To predict and preliminarily verify the potential targets and related signaling pathways of Artemisia annua L. in treating glucocorticoid-induced osteoporosis (GIOP) with kidney-yin deficiency by network pharmacology and in vitro experiments. Methods The pharmacological targets of Artemisia annua L. were obtained from TCMSP database and were converted to gene names through Uniprot database. The target genes of GIOP with kidney-yin deficiency were obtained from GeneCards database, OMIM database and Drugbank database, and the common target genes were obtained by cross analysis with drug target gene. Protein-protein interaction (PPI) network was constructed by String database, and visualization analysis and core targets screening were performed by Cytoscape 3.9.0. All common targets were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis through Metascape database. Finally, the prediction results were verified by in vitro experiments. Results Ninety-eight targets of Artemisia annua L. to GIOP with kidney-yin deficiency were screened, including 17 core genes. The results of GO and KEGG functional enrichment analysis indicated that Artemisia annua L. treating GIOP with kidney-yin deficiency was related to biological processes such as hormonal response, positive regulation of cell death and extracellular stimulation response, et al, as well as signaling pathways such as PI3K/AKT, AGE/RAGE, MAPK and IL-17 et al. The number of genes enriched in PI3K/AKT signaling pathway was the largest. In vitro experiment results showed that Artemisia annua L. promoted the proliferation of osteoblasts damaged by dexamethasone (DEX), increased alkaline phosphatase activity, activated PI3K/AKT pathway, and promoted the phosphorylation of AKT. Conclusion Artemisia annua L. treating GIOP with kidney-yin deficiency has the characteristics of multi-targets and multi-pathway, which could promote the proliferation and differentiation of osteoblasts through multiple pathways. The PI3K/AKT signaling pathway is an important pathway. Artemisia annua L. treating GIOP with kidney-yin deficiency might be related to its ability to promote the PI3K/AKT signaling pathway and promote the phosphorylation of AKT.

Protective effect of Sika Deer bone polypeptide extract on dexamethasone-induced osteoporosis in rats

BACKGROUND: Osteoporosis attacks approximately 10% of the population worldwide. Sika Deer (Cervus nippon), one of China's precious traditional medicinal animals, has been widely recorded in ancient Chinese medical books and claimed for centuries to have numerous medical benefits including bone strengthening. This study aimed to find the use of Sika Deer bone in treating osteoporosis according to traditional records and to investigate the protective effect of Sika Deer bone polypeptide extract on glucocorticoidinduced osteoporosis (GIOP) in rats. RESULTS: Sika Deer bone polypeptide extract could increase serum Ca2+ and BGP, decrease serum P3+, ALP, PTH, and CT, but had no effect on serum NO in rats with GIOP. The immunohistochemical iNOS results of the rats' distal femur were negative in each group. Besides the model group, the eNOS color reaction in osteoblasts was strongly positive in the other three groups. CONCLUSIONS: Sika Deer bone polypeptide extract can improve pathological changes in the microstructure and stimulate the expression of eNOS in osteoblasts. The protective effect on bone might be mediated by eNOS-dependent NO generation.

Relationship between LRP5 gene single nucleotide polymorphism and glucocorticoid-induced osteoporosis in children / 中华内分泌外科杂志

Objective:To investigate the relationship between the polymorphisms of two SNP loci (rs901823 and rs3736228) in the low density lipoprotein receptor-associated protein 5 (LRP5) gene and glucocorticoids-induced osteoporosis (GIOP) in children.Methods:87 children with GIOP who were treated in Beijing Aiyuhua Women’s and Children’s Hospital and Beijing Children’s Hospital affiliated to Capital Medical University from Jan. 2015 to Dec. 2020 were selected as the research objects, and 100 children with normal bone mass who were treated with corticosteroids in this hospital during the same period were enrolled as the control group. Capillary electrophoresis and fragment analysis (SNaPshot) technology were used to genotype SNP sites rs901823 (T>C) and rs3736228 (C>T) ; Quantitative real-time fluorescence quantitative polymerase chain reaction detection method was employed to determine the relative mRNA of LPR5 gene The amount of expression.Results:For the rs901823 locus of the LRP5 gene, the TT, TC, and CC genotype distribution differences between the GIOP group and the control group were statistically significant ( χ2=14.176, P=0.001) . Compared with the TT genotype, carriers of the TC and CC genotypes had a higher risk of GIOP, with OR values of 3.022 (1.189-6.387) and 5.483 (1.452-20.883) ; For academic significance, OR values were 3.412 (1.795-6.587) and 4.352 (1.215-15.982) . For the rs3736228 locus, the distribution of CC, CT, TT genotypes between the GIOP group and the control group was significantly different ( χ2=9.597, P=0.008) . Compared with CC carriers, CT genotype carriers had a significantly increased risk of GIOP, with an OR value of 5.125 (1.721-16.241) . The result of a dominant model was statistically significant, with an OR value of 4.165 (1.335-14.652) , while for TT there was no statistically significant difference between the carrier and the CC genotype ( P=0.512) , and the results of the recessive model also showed no significant statistical significance ( P=0.887) . There was a statistically significant difference in the frequency distribution of T and C alleles at rs901823 between the GIOP group and the control group ( χ2=17.298, P<0.001) , and the difference in the frequency distribution of C and T alleles at rs3736228 was also statistically significant ( χ2=9.356, P=0.002) . The relative expression level of LRP5 gene mRNA in children with GIOP was 1.34±0.26, which was significantly lower than the expression level of LRP5 gene mRNA in children in the control group of 3.06±0.42 ( t=8.248, P<0.001) . Among children with GIOP, the relative expression of LRP5 gene mRNA in patients with rs901823 locus TT, TC, and CC genotypes was statistically significant ( P<0.001) ; the differences in rs901823 locus CC, CT, TT genotype patients were significant. Pairwise comparison of the relative expression of LRP5 gene mRNA showed that there was no significant difference between the TT group and the CT group ( P>0.05) , but the expression of the CC group was significantly higher than that of the CT group and the TT group ( P<0.05) . Conclusion:The rs901823 and rs3736228 polymorphisms of LRP5 gene are correlated with the occurrence of GIOP and can be used as genetic markers for predicting GIOP in children.

Effects of Humulus lupulus L. and its active ingredient xanthohumol on preventing glucocorticoid-induced osteoporosis / 药学实践杂志

Objective To explore the effects of Humulus lupulus L. extract (HLE) and xanthohumol (XN) on preventing glucocorticoid-induced osteoporosis (GIOP). Methods The GIOP model was established by intraperitoneal injection of dexamethasone (DEX). Bone microstructure, bone mineral density and serum biochemical indexes were evaluated by Micro-CT and ELISA kits. The levels of cells proliferation and ALP activity, and the expression of bone formation related proteins were assayed with primary osteoblasts injured by DEX. Results HLE and XN significantly alleviated the bone microstructure damage, enhanced the bone mineral density, and improved the trabecular parameters in GIOP mice. In vitro experiments showed that HLE and XN can prevent bone loss not only by improving cell proliferation and ALP activity, but also through increasing the expression of bone γ-glutamic acid-containing proteins (BGP), bone morphogenetic protein 2 (BMP-2) and runt-related transcription factor 2 (Runx-2). Conclusion This study confirmed that HLE and XN had anti-GIOP effects for the first time. It provides a new resource for the development of anti-osteoporosis medications.

Kelulut honey ameliorates glucocorticoid induced osteoporosis via its antioxidant activity in rats

Objective: To explore the effects of kelulut honey on bone structure and histomorphometry against glucocorticoid-induced osteoporosis. Methods: Thirty-five male rats were used (n = 7). Twenty-eight adrenalectomized rats were divided into four groups; each group was given normal saline 0.9% (negative control), calcium water (positive control), kelulut honey (200 mg/kg/day and 400 mg/kg/day, respectively) treatment, respectively. All of them were administered with intramuscular injection of dexamethasone (120 μg/kg/day) to induce osteoporosis. Seven sham operated rats were given vehicle palm olein 0.05 mL/100 g/day by intramuscular injection and 0.1 mL/kg/day orally. All the treatments were given daily for 2 month. Lipid peroxidation and oxidative stress enzymes were measured. In addition, bone structural and histomorphometry analyses were also conducted. Results: Two-month glucocorticoid treatment increased the level of malondialdehyde and decreased superoxide dismutase significantly. No significant changes were found in the activities of catalase and glutathion peroxidase. Bone volume/tissue volume and trabecular number were significantly reduced while trabecular separation of the femoral bones was increased which corresponded to the decreased number of osteoblast surface after two months of receiving glucocorticoid treatment. Kelulut honey treatment restored the level of superoxide dismutase and reduced malondialdehyde significantly (P<0.05). Moreover, kelulut honey increased bone volume/tissue volume, trabecular number and decreased trabecular separation significantly (P<0.05), which were further confirmed by increased osteoblast surface and decreased osteoclast surface number (P<0.05). Conclusions: Kelulut honey may have potential bone protective effect, and may be a prophylaxis against glucocorticoid-induced osteoporosis.

Kelulut honey ameliorates glucocorticoid induced osteoporosis via its antioxidant activity in rats

Objective: To explore the effects of kelulut honey on bone structure and histomorphometry against glucocorticoid-induced osteoporosis. Methods: Thirty-five male rats were used (n = 7). Twenty-eight adrenalectomized rats were divided into four groups; each group was given normal saline 0.9％ (negative control), calcium water (positive control), kelulut honey (200 mg/kg/day and 400 mg/kg/day, respectively) treatment, respectively. All of them were administered with intramuscular injection of dexamethasone (120 μg/kg/day) to induce osteoporosis. Seven sham operated rats were given vehicle palm olein 0.05 mL/100 g/day by intramuscular injection and 0.1 mL/kg/day orally. All the treatments were given daily for 2 month. Lipid peroxidation and oxidative stress enzymes were measured. In addition, bone structural and histomorphometry analyses were also conducted. Results: Two-month glucocorticoid treatment increased the level of malondialdehyde and decreased superoxide dismutase significantly. No significant changes were found in the activities of catalase and glutathion peroxidase. Bone volume/tissue volume and trabecular number were significantly reduced while trabecular separation of the femoral bones was increased which corresponded to the decreased number of osteoblast surface after two months of receiving glucocorticoid treatment. Kelulut honey treatment restored the level of superoxide dismutase and reduced malondialdehyde significantly (P<0.05). Moreover, kelulut honey increased bone volume/tissue volume, trabecular number and decreased trabecular separation significantly (P<0.05), which were further confirmed by increased osteoblast surface and decreased osteoclast surface number (P<0.05). Conclusions: Kelulut honey may have potential bone protective effect, and may be a prophylaxis against glucocorticoid-induced osteoporosis.

Protective effect of dietary oils containing omega-3 fatty acids against glucocorticoid-induced osteoporosis / 한국영양학회지

PURPOSE: Glucocorticoids (GCs) are implicated in secondary osteoporosis, and the resulting fractures cause significant morbidity. Polyunsaturated fatty acids (PUFAs) play a vital role in bone metabolism. However, few trials have studied the impact of omega-3 PUFA-containing oils against GC-induced osteoporosis. Therefore, the present study was undertaken to determine whether supplementation with omega-3 PUFA-containing dietary oils such as fish oil, flaxseed oil or soybean oil can impede the development of GC-induced osteoporosis. METHODS: The fatty acids (FAs) content of oils was determined using gas chromatography. Male rats were subdivided into 5 groups (8 rats each): normal control (balanced diet), prednisolone control (10 mg/kg prednisolone daily), soybean oil (prednisolone 10 mg/kg + soybean oil 7% w/w), flaxseed oil (prednisolone 10 mg/kg + flaxseed oil 7% w/w), and fish oil (from cod liver; prednisolone 10 mg/kg + fish oil 7% w/w). RESULTS: The study data exhibited a significant depletion in bone mineral density (BMD) and femur mass in the prednisolone control compared to the normal control, accompanied with a marked decrease in the levels of plasma calcium and 1,25-(OH)₂-vitamin D₃, and elevated levels of C-terminal telopeptide (CTX), tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA). Supplementation with fish oil, soybean oil or flaxseed oil helped to improve plasma calcium levels, and suppress oxidative stress and inflammatory markers. Additionally, bone resorption was suppressed as reflected by the decreased CTX levels. However, fish oil was more effective than the other two oils with a significant improvement in BMD and normal histological results compared to the normal control. CONCLUSION: This study demonstrated that supplementation with dietary oils containing omega-3 PUFAs such as fish oil, soybean oil or flaxseed oil can play a role in the prevention of bone loss and in the regulation of bone metabolism, especially fish oil which demonstrated a greater level of protection against GC-induced osteoporosis.

Ameliorating effect of the Chinese traditional medicine Fufang Zhenzhu Tiaozhi Capsules on glucocorticoid?induced osteoporosis by antagonizing β?catenin ubiquitination and its mechanism of action / 中国实验动物学报

Objective To establish a rat model of glucocorticoid-induced osteoporosis(GIOP)and to explore the interventional effect of the Chinese medicine Fufang Zhenzhu Tiaozhi(FTZ)capsules on regulation of mitogen-activated protein kinase kinase kinase 2(MEKK2)-Wnt coupling and inhibiting β-catenin ubiquitination, and to investigate the effect of FTZ on the bone mineral density and cell osteogenic ability. Methods SPF male rats were randomly divided into normal control group,methylprednisolone group(model group),methylprednisolone + saline group(blank control group) and methylprednisolone + FTZ group(experimental group). The proximal femoral cancellous bone was examined by mi-cro-CT and histopathology,and assessment of expressions of Wnt3a,MEKK2,and β-catenin proteins. Bone mesenchymal stem cells(BMSCs were isolated and treated with serum containing FTZ,stained by alkaline phosphatase and alizarin red. The expressions of osteogenic differentiation-related genes ALP,Runx2 and OCN,the expressions of MEKK2 and β-catenin proteins,and the transcription level of β-catenin/TCF were determined. Results 1)The micro-CT imaging showed that compared with the control group, the BV/TV, Tb.Th and Tb/N expressions were significntly decreased, and Tb/sp in-creased in the experimental group(P<0.05). Region of interest(ROI)three-dimensional reconstruction of trabecular bone in the experimental group showed improvement of bone trabeculae and local bone repair. 2)The pathology using he-matoxylin and eosin staining showed that in the experimental group,the bone trabecular density was higher than that of the model group,and observed a better trabecula morphology. 3)The Wnt3a,MEKK2 and β-catenin expressions in the exper-imental group were significantly increased compared with the model model(P<0.05). 4)After treated with FTZ and BMP2,the result of alkaline phosphatase and alizarin red staining indicated an enhanced osteogenic response(P<0.05) in the GIOP rat models. 5)After treatment with seum containing FTZ,The BMSCs isolated from the GIOP rats enhanced the transcriptional activity of β-catenin/TCF/LEF(P<0.05)and promoted the expression of β-catenin and MEKK2 pro-teins(P<0.05). Conclusions FTZ can ameliorate GIOP by regulating the MEKK2-Wnt coupling and inhibiting the β-catenin ubiquitination,and improve the bone microstructure.

Effects of Huangqi Powder on femur and tibia in rats with glucocorticoid-induced osteoporosis / 中成药

AIM To study the influence of Huangqi Powder (Puerariae lobatae Radix,Astragali Radix,Mori Cortex) on femur and tibia in rats with glucocorticoid-induced osteoporosis (GIOP).METHODS Thirty one-month-old male SD rats were divided into three groups by randomized block design,which were control group (normal saline),prednisone group (3.5 mg/kg prednisone acetate),Huangqi Powder group (clinical adult dosage).Experimental test was maintained for one hundred and twenty days.Double fluorochrome labeling with calcein was performed before necropsy;bone resorption and bone formation index were determined by using blood serum;the femur structural and material mechanics were analyzed by using bone biomechanics method.The cancellous bone of proximal tibial and the cortical bone of tibial shaft static parameter and dynamic parameter were analyzed by bone histomorphometry method.RESULTS Huangqi Powder had no obvious improving effects on bone biomechanics and bone static parameter,but could increas the area,width and number of the proximal tibia bone trabecular.Mark perimeter percentage and mineralization rate of deposition could be increased.CONCLUSION Huangqi Powder can significantly increase proximal tibia cancellous bone mass and enhance bone trabecula structure of glucocorticoid-induced osteoporosis rats.

Guías para el diagnóstico, la prevención y el tratamiento de la osteoporosis inducida por glucocorticoides en el adulto / Guidelines for the diagnosis, prevention and treatment of glucocorticoid-induced osteoporosis in adults

La osteoporosis inducida por glucocorticoides (OIC) es la causa más común de osteoporosis secundaria. La pérdida ósea se produce en forma temprana, en los primeros meses siguientes a la introducción de los glucocorticoides (GC), dependiendo de la dosis diaria. La patogénesis es multifactorial y el principal efecto deletéreo es la inhibición de la formación ósea. Los GC inducen fracturas por fragilidad ósea, especialmente en la columna vertebral, y esto genera incapacidad funcional. En los últimos años se han publicado algunas guías internacionales elaboradas por consenso para la prevención y el tratamiento de la OIC. La Sociedad Argentina de Osteoporosis designó a un grupo de trabajo para elaborar una guía propia y actualizada para el diagnóstico, la prevención y el tratamiento de la OIC (GE-OIC-SAO). (AU)

Glucocorticoid-induced osteoporosis (GIO) is the most common cause of secondary osteoporosis. It occurs early, with rapid bone loss in the first few weeks after the initiation of the treatment, with a rate that is dependent mainly on the daily dose. While the pathogenesis is multifactorial, the highest inhibitory effect occurs on bone formation. Glucocorticoids induce fragility fractures, especially in spine, generating functional disability. In recent years, there have been some international guidelines developed by consensus for the prevention and treatment of GIO. The Argentinean Osteoporosis Society appointed a working group to prepare a national guide updating the diagnosis, prevention and treatment of GIO. (AU)

Treating effects of nourishing-kidnev herbs on rat models with glucocorticoid-induced osteoporosis / 国际中医中药杂志

Objective To observe the effects of nourishing-kidney herbs on rat model with glucocorticoid-induced osteoporosis.Methods 60 Wistar rats male and female half and half were randomly divided into a normal group,a model group and a nourishing-kidney group.By intramuscular injection of dexamethasone (2.5 mg/kg) twice a week to replicate osteoporosis rat model.All groups were treated for 9 weeks.Detected the BMD of femur in vitro and determined the bone metabolism marker in serum by biochemical process.Results The BMD decreased obviously (0.109± 0.007)g/cm2 and the content of TRAP in serum increased evidently (9.96± 1.15) μg/ml in the model group.In the nourishing-kidney group,the BMD was up-regulated (0.116 ± 0.007)g/cm2,and TRAP down-regulated(5.76 ± 0.85)μg/ml.Conclusion Intramuscular injection of dexamethasone can induce GIO rat model,and nourishing-kidney herbs have the effect of anti-osteoporosis.

Preventive Effects of Nitroglycerine on Glucocorticoid-induced Osteoporosis in Growing Rats / 华中科技大学学报（医学）（英德文版）

The preventive effects of nitroglycerine (NG) on glucocorticoid-induced osteoporosis in growing rats were studied. Three-month-old female Wistar rats were randomly divided into control group (CON), dexamethasone group (DXM), DXM plus a low dose NG group (NG-L), DXM plus a middle dose NG group (NG-M) and DXM plus a high dose NG group (NG-H), 8 rats in each group. The rat model of osteoporosis was developed by intramuscular injection of dexamethasone twice a week. NG 0.2, 0.4 and 1.0 mg/kg was administered by oral gavages to the treatment groups every day for 12 weeks. Rats in CON group and DXM group were treated with normal saline of the same amount. After the treatment, the bone mineral density (BMD) and bone metabolism-associated bio-chemical markers were determined. Compared with CON group, BMD of lumbar spine and femur in DXM group was decreased significantly (P<0.05 and P<0.01 respectively), blood BGP levels and NO levels reduced (both P<0.01), and TRAP level increased (P<0.05). As compared with DXM group, BMD, serum BGP and NO were increased, and TRAP decreased in NG-L group and NG-M group, but had no significant difference in comparison to CON group. All the markers other than se- rum NO and TRAP levels had no significant difference between NG-H group and DXM group.It was concluded that low or middle doses of NG could prevent glucocorticoid-induced bone loss in growing rats, but high dose of NG could not. Supplement with NO donor could be considered as a preventive treatment for glucocorticoid-induced osteoporosis in a developing skeleton.

State and prevention of glucocorticoid - induced osteoporosis in patients with primary glomerulonephritis / 中国医师进修杂志

Objective To investigate the state of glucocorticoid(GC) - induced osteoporosis (GIOP) and the current prevention of GIOP in patients with primary glomerulonephritis. Methods Primary glomerulonephritis patients receiving GC therapy were observed and bone mineral density (BMD) in the lumbar spine and the femoral neck were measured. Age, sex, body - mass - index, smoking history, the time and accumulative dose of GC treatment, and the state of osteoporosis prevention were investigated, the factors that influence the BMD were analyzed. Results A total of one hundred and twenty- three patients were included in this study. Among them, osteoporosis and os-teopenia were found in 82 patients (66.7%). Lumbar spine BMD decrease gradually with the increase of the accumulative dose of GC. There were statistical differences in the BMD of lumbar spine in patients with receving GC at the period of less than 1 month compared with other groups( 1-12 months) (P

Effect of amylin on biomechanical properties of the femur in glucocorticoid-induced osteoporosis rats / 医学研究生学报

Objective:To investigate the effect of amylin on biomechanical property of the femur in glucocorticoid-induced osteoporosis rats. Methods:Four groups of female Wistar rats(3 months old) were treated for 12 weeks as follows: ⅠNormal Control;ⅡDXM;Ⅲ DXM+AMY;Ⅳ DXM+Vitamin D_3.By intramuscular injection of dexamethasone(DXM)1mg/kg twice a week during the first 8 weeks,the animal model of Glucocorticoid induced osteoporosis was established.After 12 weeks,biomechanical properties of the femur were measured. Results:After the treatment with AMY,Bone structural mechanical(diameter) and geometrical parameters(displacement,peak load) of the femur were significantly increased(vs.DXM group,P

Effects of amylin on bone minernal density and structure parameters of bone tissue in glucocorticoid-induced osteoporosis rats / 医学研究生学报

Objectives:To investigate the effects of amylin on bone minernal density and structure parameters of bone tissue in glucocorticoid induced osteoporosis rats. Methods:Four groups of female Wistar rats (3 months old) were treated for 12 weeks as follows: ⅠNormal Control, ⅡDXM, Ⅲ DXM+AMY;Ⅳ DXM+Vitamin Da 3. By intramuscular injection of dexamethasone(XM)1mg/kg twice a week during the first 8 weeks, the animal model of Glucocorticoid induced osteopoprosis was established. After 12 weeks, BMD of the lumbar vertebrae and the femural bone were measured by DEXA. The bone morphology of the lumbar vertebrae was also determined. Results:①After the treatment with AMY, bone mineral density (BMD) was significantly increased at the lumbar spine and the femural bone. ( vs. DXM group, P

Effects of Glucocorticoid on Apoptosis of Human Bone Marrow Osteogenic Stromal Cells / 대한내분비학회지

BACKGROUND: Osteoporosis is one of the most serious side effects of long-term glucocorticoid therapy, but the mechanism of glucocorticoid-induced bone loss remains poorly defined. Glucocorticoid induces decreased bone formation and death of isolated segments of bone (osteonecrosis) suggesting that glucocorticoid excess may affect the birth or death rate of bone cells and thereby reduce their numbers. It has been known that reduction in bone formation is due to reduced proliferation in osteoblast precursor cells and reduced matrix synthesis in mature osteoblast. Here, we present evidence for dexamethasone-induced apoptosis on human bone marrow stromal cells (hBMSC). To understand the mechanism of glucocorticoid-induced osteoporosis, we investigated the effects of glucocorticoid on primary cultured hBMSC. METHEODS: Treatment with dexamethasone at the concentration of 10-9 M for 3~5 days significantly decreased cleavage tetrazolium salt WST-1 level/concentration by mitochondrial dehydrogenase in viable cells. Greater decrease was observed with higher concentration of dexamethasone (10-7 M, and 10-5 M). Apoptosis was measured by annexin V binding/propidium iodide using fluorescence-activated cell sorter (FACS) analysis and nuclear morphology stained with the fluorescence dye, Hoechst 33342. RESULTS: The level/concentration of apoptotic hBMSC (annexin V positive / PI negative) was increased with 10-9 M dexamethasone (1.2% to 5.3%) and further increased with 10-7 M, and 10-5 M concentration (11.7% and 12.5%, respectively). The same result was observed with Hoechst 33342 staining. CONCLUSION: These results indicate that glucocorticoid induces apoptosis on osteoblast precursor cell, hBMSC, and may contribute to decrease bone formation