Zoledronate regulates osteoclast differentiation and bone resorption in high glucose through p38 MAPK pathway / 南方医科大学学报

OBJECTIVE@#To investigate the effect of zoledronate (ZOL) on osteoclast differentiation and bone resorption under high glucose, and the regulation mechanism of p38 mitogen activated kinase (p38 MAPK) signaling pathway in this process.@*METHODS@#RAW264.7 cells were divided into four groups: low group, high group, low+ZOL group and high+ZOL group after induced into osteoclasts. Cell proliferation activity was determined by MTT assay. The migration of RAW264.7 cells were examined Optical microscopy. Immunofluorescence microscopy was used to observe the cytoskeleton and sealing zones of osteoclasts. After adding group 5: high + ZOL + SB203580 group, trap staining was used to identify the number of positive osteoclasts in each group. The number and area of resorption lacunae were observed by SEM. The mRNA and protein expression of osteoclast related factors were detected by real-time PCR and Western blotting.@*RESULTS@#The cells in the 5 groups showed similar proliferative activity. High glucose promoted the migration of RAW264.7 cells (@*CONCLUSIONS@#High glucose inhibits osteoclast differentiation and bone resorption. ZOL inhibits osteoclast differentiation and bone resorption in high-glucose conditions by regulating p38 MAPK pathway, which can be a new pathway for ZOL to regulate diabetic osteoporosis.

Effect of CaMKIIγ RNA interference on the expression of NFATc1,TRAP and c-Src genes in osteoclast differentiation / 实用肿瘤学杂志

Objective The aim of this study was to investigate the effect of Ca2+ /calmodulin - dependent kinase II (CaMKII)γ RNA interference on the expression of nuclear factor of activated T-cells cytoplasmic 1(NFATc1),tyrosine kinase(c-Src)and tartrate resistant acid phosphatase(TRAP)genes,and its role and molecular mechanism in osteoclast differentiation. Methods The CaMKII γ RNA interference vector was constructed by lentivirus and transfected into RAW264. 7 cells. The experiment was di-vided into three groups:A,B and C,which were the control group,negative vector group and interference vector group. After transfec-tion for 12 hours,osteoclasts induced by 50 ng/mL RANKL and the cells were harvested after induction for 5 days. Real-time quanti-tative PCR,Western blot and immunofluorescence were used to detect the expression of NFATc1,TRAP and c-Src genes in three groups. Results The mRNA levels of NFATc1,TRAP and c-Src in the group C decreased by 49. 86% ,43. 65% and 53. 57% ,re-spectively(P<0. 001),and the protein levels decreased by 54. 22% ,46. 75% and 45. 86% ,respectively(P<0. 001). There was no significant difference between the A and the B groups(P>0. 05). The fluorescence intensity of the above genes in the group C was significantly weaker than that in the A and B groups,and the formation of osteoclasts was significantly less than that in the A and B groups. Conclusion CaMKIIγ RNA interference significantly inhibited the expression of NFATc1,TRAP and c-Src genes,sugges-ting that CaMKIIγ plays a key regulatory role in osteoclast differentiation.

Construction of CaMKⅡγ RNA interference vector with lentivirus and its effect on osteoclast differentiation and bone resorption function / 实用医学杂志

Objective To investigate the effects of calmodulin-dependent kinase IIγ (GaMKIIγ) RNA interference on osteoclast differentiation and bone resorption. Methods Three CaMKIIγ recomninant RNA interference vectors were constructed using lentivirus. Negative vector was used to transfect RAW264.7 cells and the multiplicity of infection (MOI) with the optimal transfection efficiency was determined. Recombinant vectors were also used to transfect cells to determine the one with the best interference effect for following experiments.Then, the cells were divided into control group, negative vector group and interference vector group. Five days after virus transfection, osteoclastogenesis and bone resorption function were determined by TRAP staining and dentin resorption lacunae detection. Results Three CaMKIIγ recombinant interference vectors were constructed, and the optimal MOI was 30, under which transfection efficiency was about 81％. The #3 recombinant vector showed the best interference effect and the interference efficiency was up to 78.16％ at mRNA level and 67.02％ at protein level. When compared with control group, the number of multi-nucleated osteoclasts, the number and area of dentin resorption lacunaes in interference vector group decreased 59.99％、54.19％ and 57.94％ respectively (P < 0.01). No significant difference were observed between negative vector group and control group (P> 0.05).Conclusion CaMKIIγ RNA interference significantly inhibits osteoclastogenesis and bone resorption.

Expression profiles of CaMKⅡγ during osteoclast differentiation / 中南大学学报(医学版)

Objective:To study the expression profiles and the role of Ca2+/calmodulin-dependent protein kinase Ⅱγ (CaMKⅡγ) during osteoclast differentiation.Methods:Mouse RAW264.7 cells were induced for osteoclastogenesis with 50 ng/mL receptor activator of nuclear factor-κB ligand (RANKL) and the cells were harvested at 0,1,3 and 5 days after induction.Tartrate-resistant acid phosphotase staining was performed to verify osteoclasts formation.RT-PCR,Western blot and immunofluorescent cytochemistry were used to detect the CaMKⅡγ gene expression during osteoclastogenesis.Results:The osteodasts were formed at day 3 under RANKL induction and more osteoclasts were observed at day 5.At day 0,1,3 and 5,the relative level of CaMKⅡγ mRNA were (1.067±0.179),(1.840±0.070),(9.493±0.453) and (30.767±0.573),respectively,and the relative protein level were (0.454±0.065),(0.613±0.021),(0.858±0.019) and (0.980±0.023),respectively.CaMKⅡγ expression was increased in a time-dependent manner except relative protein level at day 1 (P＜0.01),which showed no significant difference at day 0 (P＞0.05).Immunofluorescence assay showed that CaMKⅡγ protein was also increased with differentiation of osteoclasts.Conclusion:The CaMKⅡγ expression was increased in a time-depended manner during osteoclast differentiation and it might play a vital role during osteoclastogenesis.

Effect of zoledronate on protein interaction between Ca2+/calmodulin-dependent protein kinaseⅡ and calmodulin and expression of downstream genes during osteoclast differentiation / 中华口腔医学杂志

Objective@#To investigate the effect of zoledronate on protein interaction between Ca2+/calmodulin-dependent protein kinaseⅡ(CaMKⅡ) and calmodulin and protein expression of nuclear factor of activation of T cells-1 (NFATc1) and tartrate resistant acid phosphatase (TRAP) during osteoclast differentiation. @*Methods@#Mouse RAW264.7 cells were divided into group A and B and were cultured. Group A was induced with 50 mg/L receptor activator of NF-κB ligand (RANKL) for osteoclastogenesis, and group B was treated with 1×10-6 zoledronate for two days from day 2. Co-immunoprcipitation (Co-IP) and reverse Co-IP were used to detect the protein-binding between CaMKⅡ and calmodulin. Western-blotting and immunofluorescent cytochemistry were also used to detect the protein level of NFATc1 and TRAP in both groups. Osteoclast formation was also analyzed. @*Results@#In group B, the number of osteoclasts, number and size of dentin resorption lacunaes were 11.3±1.5, 8.7±2.1 and (5 034.4±775.4) μm2 respevtively, which were significantly lower than those (37.7±5.7, 23.0±4.0 and [15 042.7±1 906.0] μm2) in group A (P<0.01). Co-IP and reverse Co-IP examination indicated that protein-binding between CaMKⅡ and calmodulin significantly decreased by 59.8% and 50.9% in group B compared with group A (P<0.01). The protein level of calmodulin and CaMKⅡ in total cellular proteins also significantly decreased by 52.1% and 51.5% in group B compared with group A (P<0.01). NFATc1 and TRAP protein decreased by 52.4% and 38.9% in group B than in group A (P<0.01), respectively. @*Conclusions@#Zoledronate could significantly inhibit protein-binding between CaMKⅡ and calmodulin and down-regulate protein level of NFATc1 and TRAP.

Effects of zoledronate on CaMKⅡ δ and down-stream gene expressions during osteoclast differentiation / 重庆医学

Objective To study the effect of zoledronate (ZOL) on Ca2+/calmodulin-dependent kinase Ⅱ δ (CaMK Ⅱ δ) and down-stream gene expressions during osteoclast differentiation.Methods Mouse osteoclast precursors RAW264.7 cells were divided into the control group and ZOL group.The cells in both groups were induced with 50μg/L receptor activator of nuclear factor kappa B ligand (RANKL) and were harvested on 5 d,while the cells in ZOL group were also simultaneously treated with 1 × 10-6 mol/L ZOL for 2 d.Five days later,the cells were harvested and examined osteoclastogenesis,as well as gene expressions of CaMK Ⅱ δ,nuclear factor of activated T-cells cytoplasmic 1 (NFATc1),tartrate-resistant acid phosphatase (TRAP) and cell-sarcoma receptor coactivator (c-Src).Results The number of TRAP positive multinuclear osteoclasts,number and size of dentin absorption lacunae and area in the ZOL group were (20.0±3.2),(18.0±4.2) and (6 335.3± 1 043.2)μm2 respectively,which were significantly lower than (36.0 ± 8.4),(37.2 ± 5.0) and (11 636.2 ± 3 661.1) μm2 in the control group and decreased by 44.4 ％,51.6 ％ and 45.6 ％ respectively (P＜0.01).ZOL also significantly inhibited the gene expressions of CaMK Ⅱ δ,NFATc1,TRAP and c-Src,and the mRNA levels of these genes were decreased by 44.1％,49.0％,53.8％ and 49.6％ respectively,the protein level were decreased by 43.5 ％,32.2 ％,45.5 ％ and 48.0 ％ respectively.The immunofluorescent cytochemistry detection results showed the fluorescence intensity of CaMK Ⅱ δ,NFATc1,TRAP and c-Srcin in the ZOL group was significantly weakened when compared with the control group.Conclusion ZOL could significantly inhibit the osteoclast formation and bone absorption function,and down-regulates gene expressions of CaMK Ⅱ δ,NFATc1,TRAP and c-Src in osteoclast differentiation.

Expression profiles of CaMKIIδat different stages of osteoclast differenti-ation / 中国病理生理杂志

[ ABSTRACT] AIM:To study the expression profiles and the role of Ca 2+/calmodulin-dependent kinase II delta ( CaMKIIδ) during osteoclast differentiation .METHODS:Mouse RAW264.7 cells were induced by receptor activator of nuclear factor κB ligand ( RANKL) at 50μg/L for osteoclastogenesis .Tartrate-resistant acid phosphatase ( TRAP) staining and bone resorption lacunae examination were performed to verify osteoclast formation .The expression of CaMKIIδat mR-NA and protein levels was also determined by immunofluorescent cytochemistry , RT-qPCR and Western blot at days 0, 1, 3 and 5.RESULTS:TRAP positive multinuclear cells with bone resorption function were formed after 5 d of induction. The mRNA levels of CaMKIIδdetected by RT-qPCR were 1.028 ±0.041, 2.478 ±0.087, 10.524 ±1.284 and 42.914 ± 2.667 at days 0, 1, 3 and 5, respectively, while the protein levels of CaMKIIδ detected by Western blot were 0.762, 0.963, 1.802 and 3.136, respectively.The changes of protein level were also verified by immunofluorescence cytochemis -try, in which the fluorescence intensity increased in a time-dependent manner (P<0.05).CONCLUSION:The expres-sion of CaMKIIδincreases with the differentiation of osteoclasts .CaMKIIδmay play a key role in the osteoclastogenesis .

Effect of thalidomide on development of bisphosphonate-related osteonecrosis of the jaws in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of thalidomide on the development of bisphosphonate-related osteonecrosis of the jaws (BRONJ).</p><p><b>METHODS</b>Thirty-six rats were randomly divided into groups A, B and C, and treated with saline, zoledronate and zoledronate plus thalidomide, respectively. Three weeks later, the left maxillary first molars of the rats were extracted. Four and eight weeks after tooth extraction, samples were harvested for evaluation of osteonecrosis of the jaws, microvessel density, and cell apoptosis.</p><p><b>RESULTS</b>At both of the time points, no exposed dead bone was observed at the extraction socket areas in the rats except for some small fistulas in groups B and C. Histological examination confirmed the absence of dead bone in group A, whereas small areas of dead bone were observed around the extraction socket in groups B and C. Compared with those in group A, the percentage of empty lacunae and the area of dead bone were significantly increased (P<0.01), whereas bone lacunae density was significantly decreased (P<0.01) in groups B and C at both time points. Microvessel density in groups B and C were also significantly decreased (P<0.01) by 25.87% and 55.27% at week 4, and by 45.62% and 72.84% at week 8, respectively; the apoptotic cells in groups B and C increased by 54.80% and 87.89% at week 4 (P<0.01), and by 208.08% and 250.58% at week 8 (P<0.01), respectively.</p><p><b>CONCLUSION</b>Thalidomide can aggravate zoledronate-induced early-stage BRONJ, and their osteonecrosis-inducing effect of the jaw may be attributed, at least partly, to the inhibition of angiogenesis.</p>

[Effect of zoledronate on the osteoclast adhesion and gene expression of integrin α(v) and ß3].

OBJECTIVE: To explore the effect of zoledronate (ZOL) on the osteoclast adhesion and expression of integrin α(v) and ß3 in vitro. METHODS: Mice RAW264.7 cells were used for osteoclast differentiation in vitro, and osteoclastogenesis was examined by tartrate-resistant acid phosphatase (TRAP) staining and dentin resorption lacunae examination. The cells were then divided into 2 groups, the control group and ZOL treatment group (treated with 1 x 10(-6) mol · L(-1) ZOL for 2 d). The adhesion ability of osteoclasts and mRNA and the protein expressions of integrin α(v) and ß3 were examined by crystal violet staining, real-time fluorescence quantitative polymerase chain reaction, Western blot analysis, and immunofluorescent chemistry. RESULTS: TRAP staining and dentin resorption lacunae examination revealed the formation of multi-nuclear osteoclasts. ZOL treatment significantly decreased the adhesion ability of osteoclasts (P < 0.01). In the ZOL-treated group, the mRNA levels of integrin α(v) and ß3 were 0.66 ± 0.05 and 0.59 ± 0.08, respectively. In the control group, the mRNA levels of integrin α(v) and ß3, were 1.01 ± 0.01 and 1.01 ± 0.02, respectively; these values were higher than those in the ZOL-treated group (P < 0.01). The protein level of integrin α(v) and ß3 in the ZOL-treated group (31,934.84 ± 112.91 and 18,812.79 ± 194.13) was downregulated by approximately 39.19% and 40.17%, respectively, compared with those in the control group (52,517.81 ± 211.72 and 31,441.93 ± 456.87) (P < 0.01). Immunofluorescent examination showed that the fluorescent intensities of integrin α(v) and ß3 in the ZOL-treated group (9.491 ± 0.748 and 4.744 ± 0.759) were also significantly decreased compared with those in the control group (15.159 ± 1.143 and 11.418 ± 1.095) (P < 0.01). CONCLUSION: ZOL significantly inhibits osteoclast adhesion and downregulates integrin α(v) and ß3, expression, thus contributing to the ZOL-induced inhibition of osteoclast- mediated bone resorption.

The rescue effect of RANKL on zoledronate induced acid inhibition of osteoclastogenesis and gene expression of NF-kappaB p50 and c-Jun / 生物医学工程学杂志

In this study, the rescue effect of receptor activator for nuclear factor-kappaB ligand (RANKL) on zoledronate acid (ZOL) induced inhibition of osteoclastogenesis and gene expression of NF-kappaB p50 and c-Jun was investigated. Mice calvarial osteoblasts (OBs) were harvested and co-cultured with RAW264.7 cells and the cells were divided into 4 groups and received treatment with ZOL and RANKL, either single or combined. The formation of multi-nucleated osteoclast (OC) was examined and gene expression of NF-kappaB p50 and c-Jun was detected. Group B (ZOL) showed least multi-nucleated OC and resorption lacunae among the 4 groups (P < 0.05 or P < 0.01) and it was followed by group C (ZOL+RANKL). Group D (RANKL) showed highest OC and resorption lacunae while it was similar to Group A (control) (P > 0.05). Gene expression of NF-kappaB p50 and c-Jun was the lowest in group B (P < 0.05 or P < 0.01) among the four groups and was significantly increased in group C when compared with group B (P < 0.05). Group A and D showed highest gene expression and they were similar to each other (P > 0.05). This study suggest that RANKL might partly rescue ZOL induced inhibition of osteoclastogenesis, and the effect of RANKL and ZOL on osteoclastogenesis may be mediated by NF-kappaB p50 and c-Jun.

Zoledronate inhibits TRPV5 and NFATc1 expression during differentiation of osteoclasts / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effect of zoledronate (ZOL) on osteoclast differentiation and expressions of transient receptor potential vanilloid 5 channel (TRPV5) and nuclear factor of activated T-cells cytoplasmic 1 (NFATc1).</p><p><b>METHODS</b>RAW264.7 cells were divided into two groups for treatment with RANKL for 5 days (group A) or with additional ZOL treatment in the last 2 days of RANKL treatment (group B). Osteoclastogenesis of the cells and the mRNA and protein expressions of TRPV5 and NFATc1 after the treatments were examined.</p><p><b>RESULTS</b>In group B, the number of newly generated osteoclasts (≥ 3 nuclei), number and size of dentin resorption lacunaes were 29.0 ± 2.4, 24.8 ± 1.1, and 2 030.0 ± 165.7 µm², respectively, which were significantly lower than those in group A (56.5 ± 4.5, 49.3 ± 0.9, and 3 946.7 ± 367.5 µm², respectively, P<0.01). Fluorescent intensity of TRPV5 and NFATc1 were also significantly decreased in group B (P<0.01). Compared with those in group A, TRPV5 mRNA and protein expressions in group B were down-regulated by 50.4% and 37.8%, and those of NFATc1 by 68.0% and 48.4%, respectively (P<0.01).</p><p><b>CONCLUSION</b>ZOL can significantly inhibit osteoclastogenesis and bone resorption, which may be attributed, at least partly, to ZOL-induced inhibition of TRPV5 and NFATc1 expressions.</p>

Effect of bisphosphonate on osteoclast differentiation and tartrate-resistant acid phosphatase / 中国组织工程研究

BACKGROUND:Tartrate-resistant acid phosphatase is a specific marker for osteoclast differentiation and bone resorption, which is a sign of osteoclast maturity. OBJECTIVE:To study the effect of alendronate on tartrate-resistant acid phosphatase related to osteoclast differentiation and bone resorption. METHODOsteoclasts were cultured by mouse monocyte-macrophage cellline-RAW264.7. The cells were divided into two groupcontrol group, treated with 100μg/L receptor activator of nuclear factorκB ligand factor;alendronate group, treated with 100μg/L receptor activator of nuclear factorκB ligand factor+10-7 mol/L alendronate. Osteoclastogenesis and resorption function of osteoclasts were examined at 7 days of culture. Gene expression of tartrate-resistant acid phosphatase was detected by immunofluorescence method. Western blot assay was used to detect protein expression of tartrate-resistant acid phosphatase. RESULTS AND CONCLUSION:Tartrate-resistant acid phosphatase positive multinuclear cells were observed and resorption lacunae formed in two groups. Control group showed the higher number of tartrate-resistant acid phosphatase positive multinuclear cells and larger size of resorption lacunae than the alendronate group (P<0.01). Immunofluorescence showed expression of tartrate-resistant acid phosphatase was higher in the control group than the alendronate group (P<0.01);furthermore, the protein expression of tartrate-resistant acid phosphatase was also lower in the alendronate group than the control group (P<0.01). These findings indicate that bisphosphonates could strongly inhibit osteoclastogenesis and its resorption function by inhibiting protein expression of tartrate-resistant acid phosphatase.

Bisphosphonate effects on capthesin K and bone resorption function during osteoclast differentiation / 中国组织工程研究

BACKGROUND:Studies have shown that bisphosphonates inhibit osteoclast resorption, but whether cathepsin K, a key cytokine of bone resorption, plays an effect has rarely been reported. OBJECTIVE:To study the effect of bisphosphonate on capthesin K and bone resorption function during osteoclast differentiation. METHODS:Osteoclasts were cultured by mouse monocyte-macrophage cellline-RAW264.7. The cells were divided into two groups:control group, treated with 100μg/L receptor activator of nuclear factorκB ligand factor;alendronate group, treated with 100μg/L receptor activator of nuclear factorκB ligand factor+10-7 mol/L alendronate. Osteoclastogenesis and resorption function of osteoclasts were examined at 7 days of culture and gene expression of capthesin K was detected by immunofluorescence method at 72 hours of culture. Western blot assay was used to detect capthesin K protein expression at 72 hours of culture. RESULTS AND CONCLUSION:Tartrate-resistant acid phosphatase positive multinuclear cells were observed and resorption lacunae formed in two groups. Control group showed the higher number of tartrate-resistant acid phosphatase positive multinuclear cells and larger size of resorption lacunae than the alendronate group (P<0.01). Immunofluorescence showed expression of capthesin K was higher in the control group than the alendronate group (P<0.01);furthermore, the protein expression of capthesin K was also lower in the alendronate group than the control group (P<0.01). These findings indicate that bisphosphonates could strongly inhibit osteoclastogenesis and its resorption function by inhibiting gene expression of capthesin K.

Effect of zoledronate on the osteoclast adhesion and gene expression of integrin α(v) and β3 / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore the effect of zoledronate (ZOL) on the osteoclast adhesion and expression of integrin α(v) and β3 in vitro.</p><p><b>METHODS</b>Mice RAW264.7 cells were used for osteoclast differentiation in vitro, and osteoclastogenesis was examined by tartrate-resistant acid phosphatase (TRAP) staining and dentin resorption lacunae examination. The cells were then divided into 2 groups, the control group and ZOL treatment group (treated with 1 x 10(-6) mol · L(-1) ZOL for 2 d). The adhesion ability of osteoclasts and mRNA and the protein expressions of integrin α(v) and β3 were examined by crystal violet staining, real-time fluorescence quantitative polymerase chain reaction, Western blot analysis, and immunofluorescent chemistry.</p><p><b>RESULTS</b>TRAP staining and dentin resorption lacunae examination revealed the formation of multi-nuclear osteoclasts. ZOL treatment significantly decreased the adhesion ability of osteoclasts (P < 0.01). In the ZOL-treated group, the mRNA levels of integrin α(v) and β3 were 0.66 ± 0.05 and 0.59 ± 0.08, respectively. In the control group, the mRNA levels of integrin α(v) and β3, were 1.01 ± 0.01 and 1.01 ± 0.02, respectively; these values were higher than those in the ZOL-treated group (P < 0.01). The protein level of integrin α(v) and β3 in the ZOL-treated group (31,934.84 ± 112.91 and 18,812.79 ± 194.13) was downregulated by approximately 39.19% and 40.17%, respectively, compared with those in the control group (52,517.81 ± 211.72 and 31,441.93 ± 456.87) (P < 0.01). Immunofluorescent examination showed that the fluorescent intensities of integrin α(v) and β3 in the ZOL-treated group (9.491 ± 0.748 and 4.744 ± 0.759) were also significantly decreased compared with those in the control group (15.159 ± 1.143 and 11.418 ± 1.095) (P < 0.01).</p><p><b>CONCLUSION</b>ZOL significantly inhibits osteoclast adhesion and downregulates integrin α(v) and β3, expression, thus contributing to the ZOL-induced inhibition of osteoclast- mediated bone resorption.</p>

Chronic periapical periodontitis of left maxillary first premolar with localized mineralized structure at periapical region: a case report / 华西口腔医学杂志

Chronic periapical periodontitis is characterized by destruction of periapical tissue and demonstrates translucent feature under X-ray examination. In this article, a localized mineralized structure, which showed high density under X-ray examination, was reported in a patient with chronic periapical periodontitis of left maxillary first premolar. Possible causes of the structure were analyzed and relevant literatures were reviewed.

Effect of alendronate on expressions of osteoprotegerin and receptor activator of nuclear factor κB ligand in mouse osteoblasts / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of alendronate on the expressions of osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) in mouse osteoblasts.</p><p><b>METHODS</b>Mouse calvarial osteoblasts cultured in vitro were identified by alkaline phosphatase (ALP) staining and immunofluorescence assay of OPG and RANKL expressions. The second passage of the osteoblasts were treated with different concentrations of alendronate (10(-4) to 10(-7) mol/L) for 48 h, and the changes in OPG and RANKL mRNA and protein expressions were examined using real-time PCR and Western blotting, respectively.</p><p><b>RESULTS</b>The isolated osteoblasts were positive for ALP and expressed OPG and RANKL. Real-time PCR and Western blotting showed that at the concentration of 1×10(-4) mol/L, alendronate caused an obvious down-regulation of OPG and RANKL expressions in the cells, whereas at lower concentrations, alendronate increased the expressions of both genes with the highest expressions occurring after treatment with 1×10(-5) mol/L.</p><p><b>CONCLUSION</b>High concentrations of alendronate (>1×10(-4) mol/L) decrease the expressions of OPG and RANKL, whereas low concentrations (1×10(-5) to 1×10(-7) mol/L) increase their expressions in mouse osteoblasts cultured in vitro.</p>

Construction and selection of effective mouse Smad6 recombinant lenti-virus interference vectors / 生物医学工程学杂志

This experiment was designed to construct mouse Smad6 recombinant RNA interference vectors and determine their interference effects on bone marrow mesenchymal stem cells (BMSCs). Three recombinant Smad6 RNA interference vectors were constructed by molecular clone techniques with a lenti-virus vector expressing green fluorescent protein (GFP), and the correctness of recombinant vectors was verified by DNA sequencing. Mouse BMSCs were used for transfection experiments and BMP-2 was in use for osteogenic induction of MSCs. The transfection efficiency of recombinant vectors was examined by Laser confocal scanning microscope and the interference effect of recombinant vectors on Smad6 gene expression was determined by real-time RT-PCR and Western blot, respectively. Three Smad6 recombinant RNA interference vectors were successfully constructed and their correctness was proved by DNA sequencing. After transfection, GFPs were effectively expressed in MSCs and all of three recombinant vectors gained high transfection efficiency (> 95%). Both real-time PCR and Western blot examination indicated that among three recombinant vectors, No. 2 Svector had the best interference effect and the interference effect was nearly 91% at protein level. In conclusion, Mouse recombinant Smad6 RNA interference (RNAi) vector was successfully constructed and it provided an effective tool for further studies on BMP signal pathways.

Effects of M-CSF concentration, RANKL concentration and M-CSF preinduction on osteoclastogenesis / 生物医学工程学杂志

This study was directed to the effects of macrophage-colony stimulating factors (M-CSF) concentration, recerptor activator of nuclear factor kappaB ligand (RANKL) concentration and M-CSF preinduction on osteoclastogenesis and the related resorption function. Bone marrow mononuclear cells were isolated and were divided into 4 groups. Group A underwent osteoclastogenic induction with the use of 30 ng/ml M-CSF and 50 ng/ml RANKL, while Group B received 50 ng/ml M-CSF and 100 ng/ml RANKL treatment. Both C and D Group underwent preinduction with the use of 30 ng/ml M-CSF for 3days, and then they were treated with 30 ng/ml M-CSF and 50 ng/ml RANKL, 50 ng/ml M-CSF and 100 ng/ml RANKL, respectively. Osteoclastogenesis was examined by TRAP staining 6 days after induction, and dentin resorption lacunae were detected by Scanning Electron Microscope 9 days after induction. TRAP positive multinuclear cells were observed in all groups of cells, and resorption lacunae were formed in all of them. However, more TRAP positive multinuclear cells were observed and more large resorption lacunae were detected in groups B and D than in groups A and C, respectively. The number of TRAP positive cells, number of resorption lacunae and lacuna areas in groups C and D were also greater than those in groups A and B, respectively. Higher concentration of M-CSF and RANKL and preinduction with M-CSF may benefit osteoclastogenesis and increase resorption function of osteoclast.