Research progress of nitrobenzoyl sesquiterpenoids as marine characteristic natural products / 药学学报

Sesquiterpenoids are widely found in nature, while nitrobenzoyl sesquiterpenoids are relatively rare. Twelve natural nitrobenzoyl sesquiterpenoids were all derived from marine Aspergillus fungi, which are typical natural products with marine characteristics. These natural products exhibit good antitumor, antiviral, and inhibition of osteoclast differentiation activity, especially in the treatment of osteoclast-related diseases, showing good medicinal development value. This article reviews the natural product sources, chemical structure, chemical synthesis, biosynthesis, bioactivity, and pharmacological mechanisms of nitrobenzoyl sesquiterpenoids and predicts and discusses their absorption, distribution, metabolism, excretion, toxicity (ADME/T), and drug-likeness, providing a comprehensive understanding of the natural products of nitrobenzoyl sesquiterpenoids from marine sources and their potential for pharmaceutical development.

Research progress on microRNA-21 in regulating osteoclast and osteogenic differentiation in orthodontic treatment / 口腔疾病防治

@#In the process of orthodontic treatment, the balance between the modeling of alveolar bone and the mechanical stress exerted by the appliance is key to the effective movement of orthodontic teeth. Alveolar bone modeling involves many regulatory factors, and microRNAs (miRNAs), as posttranscriptional regulatory factors, play an important role in the occurrence of bone modeling. As an important member of the miRNA family, miRNA-21 promotes the differentiation of periodontal ligament stem cells into osteoblasts and plays an important role in maintaining bone balance and preventing bone resorption as a regulator of osteoclast formation and a promoter of osteoclast differentiation. A literature review showed that miRNA-21 can regulate osteoclast function and promote bone resorption through programmed cell death 4 (PDCD4), phosphate and tension homology deleted on chromosome ten (PTEN), receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG). MiRNA-21 is highly sensitive to external mechanical stress in the process of orthodontic tooth movement. After orthodontic force is applied, miRNA-21 can promote osteoclast formation and accelerate orthodontic movement; through targeted regulation of periodontal ligament associated protein-1 (PLAP-1), it can regulate periodontal ligament remodeling in the late stage of tooth movement and improve the potential of tooth movement. In addition, miRNA-21 mediates orthodontic tooth movement (OTM) and alveolar bone remodeling in the periodontal inflammatory microenvironment. miRNA-21 can upregulate the expression of hypoxia-inducible factor-1α (HIF-1α) in periodontal ligament stem cells in a hypoxic environment. It can promote the expression of osteogenic markers, such as osteopontin (OPN), osteocalcin (OCN), alkaline phosphatase (ALP) and runt-related transcription factor 2 (Runx2), and promote osteogenic differentiation during orthodontic tooth movement.

Role of osteoclast differentiation in the occurrence of osteoarthritis of temporomandibular joint / 华西口腔医学杂志

OBJECTIVES@#This study aimed to explore the role of osteoclast differentiation in the occurrence of temporomandibular joint osteoarthritis (TMJOA).@*METHODS@#A mouse TMJOA model was constructed. Micro-CT was used to observe the changes in condylar bone during the development of TMJOA. Hematoxylin-eosin (HE) staining was used to observe the histological structure changes of the condyle of TMJOA mice. Tartrate resistant acid phosphatase (TRAP) staining was used to observe the presence of osteoclasts in TMJOA joint tissue. The synovial fluid of patients with TMJ-OA was collected to determine the effect on osteoclast differentiation.@*RESULTS@#Micro-CT revealed that the condyle of the TMJOA group had the most obvious damage in the second and third weeks, and the shape of the condyles also changed in a beak-like manner. HE staining showed that the condyle cartilage and subchondral bone structure of TMJOA mice were disordered in the second week. TRAP tissue staining showed that the number of osteoclasts of the TMJOA group obviously increased in the second week. Results of cell experiments showed that the number of osteoclast differentiation significantly increased after stimulation of synovial fluid from TMJOA patients, and the cell volume increased.@*CONCLUSIONS@#TMJOA animal models and TMJOA patient synovial cell experiments could induce osteoclast differentiation, indicating that osteoclast differentiation plays an important role in TMJOA occurrence.

Inhibition of Osteoclast differentiation based on precipitation time of titanium surfaces immersed in modified simulated body fluid / 대한치과보철학회지

PURPOSE: The purpose of this study is to investigate the changes of osteoclast differentiation inhibition according to the period of precipitation when titanium disks were immersed in Modified simulated body fluid (mSBF). MATERIALS AND METHODS: Titanium alloy (Ti grade III) disks with machined surfaces and anodized surfaces were immersed in distilled water and mSBF, respectively. The immersion periods were 7 days, 14 days, 21 days and 28 days, and the control group was immersed in distilled water for each period. RAW 264.7 cells capable of differentiating into osteoclasts were used to measure the number of adherent cells, the measurement of TRAP activity, and the expression pattern of NFATc1 by western blotting. RESULTS: The degree of inhibition of osteoclast differentiation was found to be statistically significant when the disks were immersed in mSBF for more than 14 days on both machined surfaces and anodized surfaces. There was no correlation between immersion time and cell attachment. When the disks were immersed for more than 14 days, TRAP activity was decreased and NFATc1 expression was inhibited. Futhermore, the decrease in TRAP activity and the inhibition of NFATc1 expression remained unchanged. CONCLUSION: Immersion of titanium disks in mSBF for more than 14 days can prevent RAW 264.7 cells from differentiating into osteoclasts. Inhibition activity does not change even if the immersion period is for more than 14 days.

Regulation of Osteoclast Differentiation by Cytokine Networks

Cytokines play a pivotal role in maintaining bone homeostasis. Osteoclasts (OCs), the sole bone resorbing cells, are regulated by numerous cytokines. Macrophage colony-stimulating factor and receptor activator of NF-κB ligand play a central role in OC differentiation, which is also termed osteoclastogenesis. Osteoclastogenic cytokines, including tumor necrosis factor-α, IL-1, IL-6, IL-7, IL-8, IL-11, IL-15, IL-17, IL-23, and IL-34, promote OC differentiation, whereas anti-osteoclastogenic cytokines, including interferon (IFN)-α, IFN-β, IFN-γ, IL-3, IL-4, IL-10, IL-12, IL-27, and IL-33, downregulate OC differentiation. Therefore, dynamic regulation of osteoclastogenic and anti-osteoclastogenic cytokines is important in maintaining the balance between bone-resorbing OCs and bone-forming osteoblasts (OBs), which eventually affects bone integrity. This review outlines the osteoclastogenic and anti-osteoclastogenic properties of cytokines with regard to osteoimmunology, and summarizes our current understanding of the roles these cytokines play in osteoclastogenesis.

Effect and molecular mechanism of isorhamnetin extracted from Ginkgo biloba on the differentiation of RAW264.7 cells into osteoclasts / 口腔疾病防治

Objective @#To investigate the effect and potential molecular mechanisms of isorhamnetin (ISO) extracted from Ginkgo biloba on the differentiation of osteoclasts.@*Methods@#Osteoclast precursor RAW264.7 cells were induced with RANKL to differentiate into mature osteoclasts. Different concentrations of ISO were added to RAW264.7 cells to determine its effect on osteoclast differentiation. CCK8 was used to evaluate the effect of ISO on cytotoxicity. The impact of ISO on the osteoclast differentiation process was investigated by analyzing tartrate resistance and bone resorption lacuna. Real-time PCR was performed to analyze the levels of differentiation marker genes, including tartrate resistant acid phosphatase (Trap), cathepsin K (Ctsk), and matrix metalloproteinase 9 (MMP-9); differentiation-related transcription factors, including the proto-oncogene protein c-Fos, nuclear factor of activated T-cells cytoplasmic 1(NFATc1); and the levels of downstream NF-κB p65 signaling pathway phosphorylation. Using the above-described method, we verified that ISO exerted an inhibitory effect on osteoclast differentiation and explored related molecular mechanisms. @*Results @#Different concentrations of ISO (1-10 μM) had no cytotoxic effects on RAW264.7 cells, inhibited TRAP activity and decreased the number of bone resorption lacuna during osteoclast differentiation. When applied at a concentration of 10 μM, its inhibitory effect was significant. In addition, ISO significantly reduced the expression levels of Trap, Ctsk, MMP-9, c-Fos, NFATc1 and NF-κB p65 mRNA. @*Conclusion@# ISO extracted from Ginkgo biloba extract exerted an inhibitory effect on osteoclast differentiation, and the mechanism underlying its activity may involve the inhibition of the classical NF-κB pathway.

Evaluation of osteogenic effects of BMP2 up-regulator E40071 in vitro / 药学学报

Bone morphogenetic protein 2 (BMP2) plays a key role in bone development and reestablishment. In the study, we screened up-regulators of BMP2 among 20 000 compounds through a cell-based high throughput screening model and a positive compound E40071[2-(4-(5-methyl-3-phenylpyrazolo[1,5-a]pyrimidin-7-yl) piperazin-1-yl)ethan-1-ol] was found as the positive hit. The EC50 value of E40071 was 2.73 μmol·L-1. In vitro, E40071 upregulated the mRNA levels of BMP2 and the downstream transcription factors, Runx2 and Osx in MC3T3-E1 (subclone 14). Protein expression of Runx2 was up-regulated by E40071 through induction of Smad1/5/8 phosphorylation. The alkaline phosphatase (ALP) activity was increased by E40071. Moreover, E40071 promoted the mineralization of MC3T3-E1 (subclone 14) by Alizarin red S staining. In addition, E40071 markedly inhibited osteoclast differentiation of mice macrophage Raw264.7 induced by RANKL and reduced the expression of osteoclast differentiation markers, including MMP9 and NFATc1. The results suggest that E40071 is able to promote bone formation activity of osteoblasts and inhibit differentiation of osteoclasts.

Molecular mechanism of osteoclast differentiation induced by staphylococcal lipoteichoic acid / 实用医学杂志

Objective To investigate the molecular mechanism of osteoclast differentiation induced by staphylococcal lipoteichoic acid (LTA-sa). Methods Raw264.7 cells were treated with LTA-sa in a concentration of 200 ng/mL for 0, 5, 10, 20, 40, 60 min and 0, 1, 2, 3 days respectively, and the proteins in signaling pathways associated with osteoclast differentiation were measured with western blot. In addition, Raw264.7 cells were treated with different concentrations of LTA-sa (100, 200 and 400 ng/mL) and PBS for 0, 1, 2, 3 days, the expression of TNF-α, IL-1α and IL-6 was detected with Enzyme linked immunosorbent assay (ELISA). Results (1)Western blot showed that, under stimulation of LTA-sa, IκB-α decreased at 5 min and 10 min, while the phosphorylation of nuclear factor κB increased at 10 min . In addition , NFATc1 increased in 2 and 3 days gradually. The above results were statistically analyzed, and the difference was significant in statistics (P < 0.001). (2)ELISA showed that the expression of IL-6 increased in 2 and 3 days along with the increasing concentration and prolonging stimulation time of LTA-sa. Data were statistically analyzed, the difference was significant in statistics (P < 0.001). Conclusion LTA-sa promotes osteoclast differentiation through the NF-κB signaling pathway and the secretion of IL-6.

Flavonoids isolated from Tridax procumbens (TPF) inhibit osteoclasts differentiation and bone resorption

BACKGROUND: The Tridax procumbens flavonoids (TPF), are well known for their medicinal properties among local natives. The TPF are traditionally used for dropsy, anaemia, arthritis, gout, asthma, ulcer, piles, and urinary problems. It also used in treating gastric problems, body pain, and rheumatic pains of joints. The TPF have been reported to increase osteogenic functioning in mesenchymal stem cells. However, their effects on osteoclastogenesis remain unclear. The TPF isolated from T. procumbens and investigated the effects of the TPF inhibit on osteoclast differentiation and bone resorption activities using primary osteoclastic cells. Osteoclast formation was assessed by counting the number of tartrate resistant acid phosphatase (TRAP) positive multinucleated cells and by measuring both TRAP activities. RESULTS: The TPF significantly suppressed the RANKL-induced differentiation of osteoclasts and the formation of pits in primary osteoclastic cells. The TPF also decreased the expression of mRNAs related to osteoclast differentiation, including Trap, Cathepsin K, Mmp-9, and Mmp-13 in primary osteoclastic cells. The treatment of primary osteoclastic cells with the TPF decreased Cathepsin K, Mmp-9, and Mmp-13 proteins expression in primary osteoclastic cells. CONCLUSION: These results indicated that TPF inhibit osteoclastogenesis and pits formation activities. Our results suggest that the TPF could be a potential anti-bone resorptic agent to treat patients with bone loss-associated diseases such as osteoporosis.

The influence of osteoclasts during the repairs of tooth root in rats model of tooth resorption by intermittent injection of parathyroid hormone (PTH) / 重庆医学

Objective To investigate the role of PT H (1-34 ) on the expression of receptor activator factor of NF-κB ligand (RANKL) in the induction of osteoclasts and its effect to osteoclasts on compression side during the repairs of tooth root in rats model of tooth resorption by intermittent injection of small dose of PTH (1-34) .Methods After the model of tooth resorption was established in rats 6-8 weeks in age ,63 male SD rats were divided in three groups .Rats in the control group were not given injec-tions for any drugs ;The negative control group were given injections for normal saline 6μg/kg subcutaneously every other day ;The experimental group were given injections for PTH (1-34) 6 μg/kg(PTH :1 μg/mL) subcutaneously every other day ;then rats in every group were killed on the day 0 ,7 ,10 ,14 ,17 ,21 ,25 .TRAP staining for counting TRAP-positive stained osteoclasts ,calculat-ing the mean ;Ligand RANKL immunohistochemistry and using image-pro-plus image analysis system to measure the average opti-cal density value of compression side .Results On the day of discontinuation ,the tooth resorption continued in each group ;the num-ber of osteoclasts between every two arrays there were no significant statistic differences (P>0 .05);RANKL immunohistochemis-try :Compared with control group and the negative control group ,the experimental group significantly increased in early stage ,and reduced in latest stage(P<0 .05) .Conclusion It indicated that intermittent injection of small dose PTH (1-34) did not cease the rats tooth resorption which occured during the period of tooth repair .

Correlation between serum ODF and OCIF levels in lung cancer patients with bone metastasis / 中国肿瘤临床

Objective:This study was aimed to investigate the value of osteoclast differentiation factor (ODF) and osteoclastogen-esis inhibitory factor (OCIF) detection for clinical diagnosis and assessment of patient condition in bone metastasis of lung cancer. Methods:Data from 186 lung cancer patients who were preliminary diagnosed between July 2009 and April 2012 were analyzed. Cas-es were divided into the bone metastasis group with 82 cases (group A) and the non-bone metastasis group with 104 cases (group B). Concentrations of serum ODF and OCIF in each group were detected by ELISA. Results: ODF and OCIF values of group A were (32.22±6.22) ng/L and (41.23±8.13) ng/L, respectively, which were significantly higher than the corresponding values in group B [(8.35 ±5.42) ng/L and (10.15±4.42) ng/L]. The differences between the two groups were statistically significant (P0.05). Conclusion:The serum ODF and OCIF concentrations significantly increase when bone metastasis oc-curs in lung cancer patients. Hence, these variables are useful as indices for monitoring bone metastases and evaluating patient condi-tion. An extensive application prospect is proposed.

Inhibition of Osteoclast Differentiation and Bone Resorption by Poria cocos Wolf Extract / 대한골다공증학회지

OBJECTIVES: Osteoclast differentiation and bone resorption are considered a potential therapeutic target to the treatment of erosive bone diseases, including osteoporosis and rheumatoid arthritis. Poria cocos Wolf (PCW), commonly used herbal medicine, has previously been reported to induce anti-inflammatory effect and anti-cancer effect, and to modulate immunologic responses. However, the effects of PCW on osteoclasts, and its detailed mechanisms are not proven. Therefore, we examined the inhibitory mechanism of PCW on osteoclast differentiation and bone resorption. MATERIALS AND METHODS: To analyze the effects of PCW on osteoclast differentiation, we examined osteoclast differentiation in bone marrow macrophages (BMMs) treated with or without of PCW by TRAP staining. The expression of c-Fos, NFATc1, TRAP and OSCAR mRNA was determined by RT-PCR and the protein levels of c-Fos, NFATc1, p38, ERK, JNK, Akt and IkappaB were assessed by western blot. Also, we evaluated the effect of PCW on bone resorption using hydroxyapatite plate. RESULTS: PCW significantly inhibited RANKL-mediated osteoclast differentiation without any evidence of cytotoxicity. We founded that PCW strongly inhibited RANKL-induced osteoclast formation when added during the early stage of cultures, suggesting that PCW acts on osteoclast precursors to inhibit RANKL/RANK signaling. Among the RANK signaling pathways, PCW inhibited the phosphorylation of p38 and JNK, also inhibited RANKL-induced expression of c-Fos, NFATc1, TRAP and OSCAR. In addition, PCW suppressed the bone resorption of mature osteoclasts. CONCLUSIONS: These findings suggest that PCW may be a potential novel drug for bone disorders by targeting the differentiation of osteoclasts as well as their functions.

Bone resorptive activity of osteoclast-like cells generated in vitro by PEG-induced macrophage fusion

Normal bone remodeling is maintained by a balance between osteoclast and osteoblast activity, whereas defects in osteoclast activity affecting such balance result in metabolic bone disease. Macrophage-macrophage fusion leading to multinucleated osteoclasts being formed is still not well understood. Here we present PEG-induced fusion of macrophages from both U937/A and J774 cell lines and the induced differentiation and activation of osteoclast-like cells according to the expression of osteoclast markers such as tartrate resistant acid phosphatase (TRAP) and bone resorptive activity. PEG-induced macrophage fusion, during the non-confuent stage, signifcantly increased the osteoclastogenic activity of macrophages from cell lines compared to that of spontaneous cell fusion in the absence of PEG (polyethylene glycol). The results shown in this work provide evidence that cell fusion per se induces osteoclast-like activity. PEG-fused macrophage differential response to pretreatment with osteoclastogenic factors was also examined in terms of its ability to form TRAP positive multinucleated cells (TPMNC) and its resorptive activity on bovine cortical bone slices. Our work has also led to a relatively simple method regarding those previously reported involving cell co-cultures. Multinucleated osteoclast-like cells obtained by PEG-induced fusion of macrophages from cell lines could represent a suitable system for conducting biochemical studies related to basic macrophage fusion mechanisms, bone-resorption activity and the experimental search for bone disease therapeutic alternatives.

Effects of mechanical tensile stress on the expression of ODF mRNA in osteoblasts differentiated from rBMSCs in vitro / 医用生物力学

Objective To investigate the correlation between mechanical tensile stress and the expression of ODF mRNA in osteoblasts differentiated from rBMSCs, and elucidate the mechanism for osteoclastogenesis regulated by osteoblasts in bone modeling and remodeling during the process of orthodontic tooth movement. Method rBMSCs derived osteoblasts were isolated and cultured in vitro, and subjected to static mechanical tensile stress of 1, 3, 5 kPa or dynamic tensile stress of 3, 5 kPa at 0.017 Hz using the cellular tensile stress system for 24 h. The control groups were subjected without any strain. Cells were collected in 0, 3, 6, 9, 12, 24, 48 h respectively after stress loading. The expression patterns of ICAM-1 mRNA were examined by semiquantitative RT PCR assay. Results ODF mRNA level significantly decreased after dynamic tensile strain, compared with the control groups；the effects of inhibition did not positively correlated with the magnitude of strain; the expression of ODF mRNA gradually decreased at 6 h, significantly decreased at 9 h, then slightly rebounded and still stayed at a considerably lower level, reached the minimum transcription at 48 h. Conclusions The mechanical tensile strain can regulate osteoclastogenesis by inhibiting the expression of ODF in osteoblasts derived from rBMSCs. It could lead to a better understanding of the molecular basis for osteoblast osteoclast communication in bone resorption induced by the application of mechanical strain during the orthodontic tooth movement.

Hexane-Soluble Fraction of the Common Fig, Ficus carica, Inhibits Osteoclast Differentiation in Murine Bone Marrow-Derived Macrophages and RAW 264.7 Cells

Osteoclasts, derived from multipotent myeloid progenitor cells, play homeostatic roles in skeletal modeling and remodeling, but may also destroy bone in pathological conditions such as osteoporosis and rheumatoid arthritis. Osteoclast development depends critically on a differentiation factor, the receptor activator of NF-kappaB ligand (RANKL). In this study, we found that the hexane soluble fraction of the common fig Ficus carica (HF6-FC) is a potent inhibitor of osteoclastogenesis in RANKL-stimulated RAW264.7 cells and in bone marrow-derived macrophages (BMMs). HF6-FC exerts its inhibitory effects by suppression of p38 and NF-kappaB but activation of ERK. In addition, HF6-FC significantly decreased the expression of NFATc1 and c-Fos, the master regulator of osteoclast differentiation. The data indicate that components of HF6-FC may have therapeutic effects on bone-destructive processes such as osteoporosis, rheumatoid arthritis, and periodontal bone resorption.

Expression of Osteoprotegerin and Osteoclast Differentiation Factor in Human Periodontal Ligament Fibroblast Cells / 대한치주과학회지

Recently, soluble TNF receptor homolog osteoprotegerin (OPG) and its membrane-bound ligand osteoclast differentiation factor (ODF) were found to regulate osteoclast formation and function, and bone metabolism. It is now well established that ODF acts via RANK expressed on hematopoietic osteoclast precursor cells to facilitate their differentiation to osteoclasts, and OPG prevents the formation of osteoclasts by interfering the binding of ODF and RANK. Expression of OPG and ODF was believed to be closely related to the pathogenesis of bone resorption and destruction from osteoporosis, periodontal diseases, malignant bone tumor, and arthritis. The periodontal ligament fibroblasts (PDLF), located between the tooth and tooth socket, has been thought to play an important role in maintaining bone homeostasis of periodontal tissues. However, the exact mechanism by which bone formation and resorption are regulated by PDLF is not well understood. In this study we have prepared primary cultures of human PDLF from periodontium of malaligned tooth extracted due to orthodontic reason, and determined steady state or inflammatory signal-induced OPG and ODF expression using RT-PCR and western blot analysis. OPG and ODF mRNA and protein were expressed constitutively in the PDLF and these expression were slightly increased by osteotropic cytokine IL-1beta. Lipopolysaccharide-treated PDLF showed decrease in OPG mRNA and protein expression, and increase in ODF mRNA and protein expression. These results indicated that PDLF influence the osteoclastogenesis by OPG and ODF expression in the inflammatory situation as well as physiological condition, and thereby pathogenesis of periodontal alveolar bone destruction.

Effects of strain force on the expression of osteoclast differentiation factor and osteoclasto-genesis inhibitory factor in human periodontal ligament cells / 实用口腔医学杂志

Objective:To investigate the effects of strain force on t he expression of osteoclast differentiation factor(ODF) and osteoclasto-genesis i nhibitory factor(OCIF) in human periodontal ligament cells (HPDLCs). Met hods: HPDLCs were subjected to cyclic strain force for 0, 6, 12 and 24 h ours, mRNA expression of ODF and OCIF were determined by RT-PCR. Result s:After treatment of the cells for 0,6,12 and 24 hours the ODF/?-actio n values were 0.7280?0.0261,0.6831?0.0411,0.5801?0.2230 and 0.4572?0.0373( P0.05) respectively.Conclusion:Strain force may decrease the expression of ODF and increase the expression of OCIF.

Effect of Sonicated Extract of Treponema Denticola on Osteoclast Differentiation / 대한치주과학회지

Alveolar bone destruction is a characteristic of periodontal disease. Treponema denticola are found in significantly increased numbers in the sites affected with periodontal disease. In order to clarify the role of T. denticola in destruction of alveolar bone in periodontal disease, this study was undertaken to determine the effect of sonicated extract of T. denticola on osteoclast differentiation in co-culture system of mouse bone marrow cells and calvaria cells. The ability of osteoclast formation was estimated by counting the number of tartrate resistant acid phosphatase(TRAP) positive cells. Sonicated extract of this bacteria stimulated osteoclast formation in a dose dependent manner(p<0.05). Indomathacin, an inhibitor of prostaglandin synthesis, decreased osteoclast formation induced by sonicated extract of this bacteria(p<0.05). Extract-induced osteoclast formation was decreased, when sonicated extract of bacteria was heated(p<0.05). These findings suggest that T. denticola induces osteoclast differentiation, and protein component of this bacteria and PGE2 may play an important role in this process.

Effect of 17beta-Estradiol and 1,25-Dihydroxyvitamin D3 on Interleukin-6 Production of Periodontal Ligament Cells / 대한치주과학회지

Interleukin-6(IL-6) stimulate osteoclast differentiation. 17beta-estradiol, 1,25-dihydroxyvitamin D3(1,25-(OH)2D3) and interleukin-1beta inhibit or stimulate osteoclast differentiation by decreasing or increasing the synthesis of interleukin-6(IL-6) from stromal/osteoblastic cells, respectively. Periodontal ligament(PDL) cells reside between the alveolar bone and the cementum and have osteoblastic characteristics. To estimate the effect of 17beta-estradiol and 1,25(OH)2D3 on IL-6 production of PDL cells, PDL cells were treated with 17beta-estradiol or 1,25-(OH)2D3 in the absence or the presence of IL-1beta. The concentration of IL-6 produced form PDL cells was determined by enzym linked immunosorbent assay(ELISA). In unstimulated PDL cells, we detected constitutive production of IL-6 at 1st and 2nd day. IL-1beta increased IL-6 synthesis at 1st day and 2nd day. 17beta-estradiol had no significant effect on the secretion of this cytokine, either constitutively or after stimulation with IL-1beta(0.05 ng/ml). 1,25-(OH)2D3(10(-8)M) decreased not only constitutive IL-6 production but also IL-1beta-induced IL-6 production at 2nd day. These results suggest that 1,25-(OH)2D3 may control IL-1beta-induced osteoclast differentiation by decreasing IL-1beta-induced IL-6 secretion of PDL cells.

Regulating effect of 17?-estradiol on osteoprotegerin and osteoclast differentiation factor expressions in osteoblasts from newborn rats / 中华内分泌代谢杂志

Osteoblasts (OB) isolated from newborn SD rats were cultured in vitro.After treatment with different concentrations of 17?-estradiol (10~(-11)-10~(-6)mol/L),the mRNA expressions of osteoprotegerin (OPG) and osteoclast differentiation factor (ODF) in OB were measured by RT-PCR.17?-estradiol increased the expression of OPG in OB with the maximal effect at the concentration of 10~(-8) mol/L.No significant difference was observed in the expression of ODF in OB with different concentrations of 17?-estradiol.The therapeutic effect of estrogen on osteoporosis appears to be related to the enhanced OPG expression in OB at physiological concentration of estrogen.