雌二醇对成骨细胞OPG和RANKL的影响

目的探讨不同浓度17β-雌二醇(E2)作用下体外培养大鼠成骨细胞护骨素(OPG)、细胞核因子-κB受体活化因子配体(RANKL)的表达及雌激素治疗骨质疏松的机制。方法采用不同浓度(10-10、10-9、10-8、10-7mol/L)17β-E2刺激培养的大鼠成骨细胞(OB),RT-PCR方法检测OPG、RANKL mRNA的表达。结果原代OB呈多角形、梭形,传代OB胞核较大,细胞质内见黑色颗粒,细胞形态为多角形或梭形,见突起,三代细胞碱性磷酸酶染色阳性,胞质见大量灰黑色颗粒,细胞鉴定符合成骨细胞特征。不同浓度(10-9、10-8、10-7mol/L)17β-E2对OB OPG mRNA表达具有显著的增强作用(P<0.05),其中10-8mol/L 17β-E2对OB OPG mRNA表达最高,与对照组比较差异有统计学意义(P<0.01),而10-10mol/L 17β-E2对成骨细胞OPG mRNA表达几乎无影响,与对照组比较无显著差异(P>0.05),10-10、10-9、10-7mol/L 17β-E2对成OB RANKL mRNA表达几乎无影响,与对照组比较无明显差异(P>0.05),其中10-8mol/L17β-E2对OB RANKL mRNA的表达具有明显的抑制作用,其与对照组比较差异明显(P<0.05)。结论雌激素治疗骨质疏松的作用可能与其促进成骨细胞OPG表达、抑制RANKL表达相关。     

淫羊藿甙对大鼠成骨细胞护骨素、RANKL表达的影响

目的观察淫羊藿甙对体外培养大鼠成骨细胞护骨素(OPG)、核因子-kB受体活化因子配体(RANKL)mRNA表达的影响。方法用酶消化法分离24h内新生SD大鼠颅盖骨成骨细胞,进行原代培养。在培养液中加入不同浓度的淫羊藿甙(10~(10)～10~(14)mol/L),培养48h后,抽提总RNA,采用半定量RT-PCR法检测成骨细胞中OPG和RANKL mRNA表达的变化。结果淫羊藿甙可明显促进成骨细胞OPG mRNA的表达,抑制RANKL mRNA的表达,且呈浓度依赖性,均以10~(-7)mol/L时作用最显著(P＜0.05)。预先用淫羊藿甙干预成骨细胞,可逆转地塞米松的降低OPG mRNA(0.570±0.093vs 1.083±0.081)、升高RANKL mRNA(1.079±0.050vs 0.718±0.082)的作用(均P＜0.05)。结论淫羊藿甙可以上调OPG基因表达,下调RANKL基因表达,从而调节骨吸收,这可能是淫羊藿甙防治骨质疏松症的重要机制之一。     

氟化物对成骨细胞OPGL mRNA和M-CSF mRNA表达的影响

目的探讨氟对成骨细胞的骨保护蛋白配体(OPGL)mRNA和巨噬细胞集落刺激因子(M-CSF)mRNA表达的影响.方法应用酶消化法分离小鼠乳鼠成骨细胞,取第3代成骨细胞,加入不同浓度的氟6 h,提取细胞总RNA,通过逆转录-聚合酶链式反应(RT-PCR)方法,观察成骨细胞分泌的OPGL和M-CSF表达的变化.结果在氟的作用下,成骨细胞的OPGL mRNA和M-CSF mRNA的表达呈上升趋势,但未达到统计学差异水平.结论氟有可能通过上调OPGL和M-CSF的表达,提高破骨细胞的骨吸收活性.     

氟对小鼠成骨细胞RANKL mRNA表达的影响

目的探讨氟对成骨细胞细胞核因子κB受体活化因子配体（RANKL）mRNA表达的影响。方法分离小鼠乳鼠成骨细胞，取第3代成骨细胞，分别培养于含有矿化液（维生素C50mg／L、β-甘油磷酸钠10mmol／L、地塞米松10^-7md／L）和不含矿化液的L-DMEM培养基中，按染氟剂量[F-终剂量为0（对照组）、1、10、100、1000、10000、20000μg／L]分组，染氟72h后，提取细胞总RNA，通过反转录一聚合酶链反应（RT-PCR）方法，观察含矿化液和不含矿化液情况下培养的成骨细胞在不同染氟剂量下RANKLmRNA表达的变化。结果与对照组比较，非矿化染氟（不含矿化液）1000μg/L组RANKLmRNA表达升高（P〈0．01），10000μg／L组RANKLmRNA表达降低（P〈0．01）；与对照组比较，矿化染氟100、1000μg／L组RANKLmRNA表达升高（P〈0.01）；相同染氟剂量，矿化染氟0、1、10、100、1000、10000μg／L组与非矿化染氟组比较，RANKLmRNA表达降低（P〈0．01）。结论染氟可以影响成骨细胞表达RANKLmRNA；同等染氟剂量下，矿化处理可降低成骨细胞RANKLmRNA表达。     

糖尿病对大鼠种植体周围OPG和RANKL表达的影响

建立糖尿病大鼠实验动物模型成功后,将大鼠分为糖尿病种植组（T组）,糖尿病对照组（T0组）,正常种植组（C组）,正常对照组（C0组）。T组及C组的胫骨近骺端种植纯钛种植体,分别于植入后1、2周处死动物,采用免疫组化和实时定量PCR方法检测种植体周围骨组织中骨保护因子（OPG）和破骨细胞核因子kB受体活化因子配体（RANKL）的表达。结果OPG和RANKL表达在骨基质、成骨细胞及骨髓基质细胞中,T、C组阳性信号增强,髓腔内更加明显;T、T0组大鼠皮质骨孔隙明显多于C、C0组。T、C组第1、2周OPG均较C0组增加,T组第2周比T0组增加;T组第1、2周RANKL均比C0、T0组增加（p均〈0．05）。提示糖尿病可能通过OPG和RANKL通路使种植体植入周围骨组织中破骨细胞的形成增加,削弱了糖尿病种植体与周围骨组织的骨整合。     

铁离子对人成骨细胞RANKL/OPG基因及蛋白表达的影响

目的研究人成骨细胞(hFOB1.19)在不同铁离子状态下RANKL/OPG基因及蛋白的表达。方法成骨细胞株(hFOB1.19)在DMEM/F-12培养基培养传代至第3代后,用不同终浓度枸橼酸铁铵(50、100、200μmol/L)加入细胞培养基中干预24h,用RT-PCR方法和免疫印迹法(WesternBlot)检测干预后成骨细胞的RANKL、OPGmRNA和蛋白表达并计算RANKL/OPG比率。结果RT-PCR检测结果显示,对照组、50、100、200μmol/L组RANKL/OPGmRNA表达比分别为0.56±0.13、0.58±0.01、0.69±0.01、1.84±0.92;Westernblot结果显示,对照组、50、100、200μmol/L组RANKL/OPG蛋白表达比分别为0.82±0.66、0.82±0.64、1.09±0.11、1.25±0.14。统计学分析显示,在mRNA和蛋白水平,100和200μmol/L浓度的枸橼酸铁铵干预后RANKL/OPG比值明显高于对照组(P0.05),50μmol/L枸橼酸铁干预后与对照组差异无统计学意义。结论不同浓度枸橼酸铁铵可以影响人成骨细胞RANKL/OPG基因及蛋白的表达,进而可能影响骨形成和骨吸收。     

OPG/RANK/RANKL通路在骨质疏松与动脉粥样硬化相关性中的作用机制研究进展

骨质疏松和动脉粥样硬化是伴随老年患者的常见疾病,发病率高,并发症多,是死亡率增加的主要危险因素。随着患者年龄的增加,二者的临床联系也越来越紧密。OPG/RANK/RANKL通路是近年来研究的热点,是骨质疏松研究史上里程碑式的发现。近年来逐渐认识到这种信号传导途径在动脉粥样硬化中同样起着不可估量的作用,研究者对该通路与动脉粥样硬化之间进行了潜在而广泛的研究。本文就OPG/RANK/RANKL通路作为它们之间联系的桥梁,初步探讨共同的发病机制及临床联系,为临床工作中以这些分子作为靶点设计和药物制备提供进一步的综合理念。     

氟对小鼠成骨细胞增殖与分化及骨保护蛋白和核因子κβ受体活化因子配体mRNA 表达的影响

目的 观察氟对体外培养的小鼠成骨细胞增殖、分化、骨保护蛋白(OPG)mRNA及核因子κβ受体活化因子配体(RANKL)mRNA表达的影响.方法 取出生1～2 d昆明小鼠颅盖骨,分离成骨细胞后进行传代培养.按培养液中加入不同浓度氟化钠(NaF)将成骨细胞分为0(对照)、10-8、10-7、10-6、10-5、10-4、10-3 mol/L组,分别在培养72 h或120 h后检测氟对成骨细胞增殖、分化(碱性磷酸酶,ALP)的影响;提取成骨细胞总mRNA,采用RT-PCR方法分析成骨细胞OPG mRNA、RANKL mRNA表达,并进行半定量分析.组间比较采用单因素方差分析,两两比较采用LSD-t检验.结果 培养72 h后,成骨细胞增殖组间比较差异有统计学意义(F=13.806,P<0.05);与对照组(0.434±0.010)比较,10-7～10-4mol/L组成骨细胞增殖明显增加(0.448±0.010、0.453±0.013、0.454±0.016、0.449±0.018,P均<0.05),10-3 mol/L组成骨细胞增殖降低(0.401±0.009,P<0.05).成骨细胞ALP活性组问比较差异有统计学意义(F=9.021,P<0.05);其中10-7～10-5 mol/L组[(2.447±0.756)×106、(2.603±0.183)×106、(2.687±0.886)×106 U/L]ALP活性明显高于对照组[(1.677±0.682)×106U/L,P<0.05或<0.01];10-4mol/L组[(1.479±0.366)×106 U/L]ALP活性明显低于对照组(P<0.05).OPG mRNA表达组间比较差异有统计学意义(F=11.299,P<0.05);与对照组(11000±0.000)比较,10-7～10-4 mol/L组表达增强(1.058±0.027、1.053 ±0.026、1.088±0.055、1.069±0.008,P<0.05或<0.01),10-3mol/L组表达降低(0.941±0.029,P<0.05).成骨细胞RANKL mRNA表达组间比较差异无统计学意义(F=1.311,P>0.05).RANKL mRNA/OPG mRNA比值,在104～10-5mol/L组逐渐降低,10-4、10-3mol/L组升高,但组间比较差异无统计学意义(F=1.376,P>0.05).结论 氟对小鼠成骨细胞增殖、分化呈双向调节作用,表现为低剂量刺激而高剂量抑制.低剂量染氟可能通过增加成骨细胞OPG的表达来抑制破骨细胞的分化和成熟,抑制骨吸收;而高剂量可能通过降低OPG的表达来促进破骨细胞的分化、成熟,促进骨吸收.

Abstract：

Objective To investigate the effect of sodium fluoride(NaF) on proliferation, differentiation and the mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor κβ ligand (RAN KL) of mouse osteoblasts. Methods Osteoblasts were isolated from calvarias of Kunming mice born in 1 - 2 d and cultured. Various concentrations of NaF(0, 10-8, 10-7, 10-6, 10-5, 10-4, 10-3mol/L) were added to the culture medium, the proliferation and activity of alkaline phosphatase(ALP) was determined after 72 h or 120 h. The expression of OPG mRNA and RANKL mRNA was analyzed by semi-quantification RT-PCR. Difference among groups was analyzed by One-Way AN0VA. Difference between two groups was analyzed by LSD-t test. Results There was significant difference in cell proliferation among groups after 72 h(F = 13.806, P < 0.05). Compared with control group(0.434 ± 0.010) , the proliferation was significantly induced in 10-7 - 10-4 mol/L groups treated osteoblasts (0.448 ± 0.010, 0.453 ± 0.013, 0.454 ± 0.016, 0.449 ± 0.018, all P< 0.05), and was significantly suppressed in 10-3 mol/L group(0.401 ± 0.009, P < 0.05). There was statistic difference in the activity of ALP among groups(F = 9.021, P < 0.05). Compared with control group (1.677 ± 0.682), the activity of ALP significantly increased in 10-7 - 10-5 mol/L groups[ (2.447 ± 0.756) × 106, (2603 ± 0.183) × 106, (2.687 ± 0.886) × 106 U/L, P < 0.05 or P < 0.01 ] and significantly decreased in 10-4 mol/L group[ (1.479 ± 0.366) × 106 U/L, P < 0.05 ]. There was significant difference in the expression of OPG mRNA among groups(F = 11.299, P< 0.05). Compared with control group (1.000 ± 0.000), the expression of OPG mRNA was significantly increased in 10-7 - 10-4 mol/L groups( 1.058 ± 0.027, 1.053 ± 0.026, 1.088 ± 0.055, 1.069 ± 0.008, P < 0.05 or P < 0.01) , while significantly decreased in 10-3 mol/L group (0.941 ± 0.029, P< 0.05). There was no difference in RANKL mRNA expression among groups (F= 1.311, P> 0.05). The ratio of RANKL/OPG decreased with increasing doses of fluoride and increased in 10-4, 10-3 mol/L groups, but there was no difference between groups(F = 1.376, P> 0.05). Conclusions A biphasic pattern of proliferation and differentiation has been induced in mouse osteoblasts, which manifests stimulation effect in low doses and suppression in higher doses. Low doses of sodium fluoride suppress differentiation and maturation of osteoblasts by increasing expression of OPG mRNA, while high doses of sodium fluoride enhance differentiation and maturation of osteoblasts by decreasing expression of OPG mRNA.     

降钙素基因相关肽对维甲酸致老年骨质疏松大鼠OPG/RANKL信号通路的影响及疗效

目的探讨降钙素基因相关肽(CGRP)对维甲酸致老年骨质疏松大鼠骨保护素(OPG)/核因子κB受体活化因子配体(RANKL)信号通路的影响及疗效。方法 72只15月龄雄性SD大鼠随机分为对照组、维甲酸组、CGRP组和CGRP8-37(CGRP拮抗剂)组,每组18只;后3组用维甲酸80 mg·kg-1·d-1灌胃,1次/d,连续灌胃2 w。维甲酸组腹腔注射生理盐水1 ml,1次/d,6次/w;CGRP组腹腔注射1 ml CGRP(30μg/kg),1次/d,6次/w;CGRP8-37组先腹腔内注射1 ml CGRP8-37(30μg/kg),再向腹腔内注射1 ml CGRP(30μg/kg),1次,6次/w;以上各组均干预2 w。采用双能X射线骨密度仪检测大鼠股骨骨密度(BMD);比较各组血清白细胞介素(IL)-6、IL-1、肿瘤坏死因子(TNF)-α、OPG和RANKL水平;RTPCR法检测各组大鼠骨组织OPG mRNA和RANKL mRNA表达。结果与对照组比较,维甲酸组大鼠左、右股骨BMD明显降低(P0.05);与维甲酸组比较,CGRP组大鼠左、右股骨BMD均显著升高(P0.05);而CGRP8-37组大鼠左、右股骨BMD均明显低于CGRP组(P0.05)。与对照组比较,维甲酸组大鼠血清OPG水平和骨组织OPG mRNA表达明显下降,而血清RANKL、IL-1、IL-6、TNF-α水平和骨组织RANKL mRNA表达明显升高(P0.01);与维甲酸组比较,CGRP组大鼠血清OPG和骨组织OPG mRNA明显升高,而血清RANKL、IL-1、IL-6、TNF-α水平和骨组织RANKL mRNA表达显著降低(P0.01);CGRP8-37组大鼠血清OPG水平和骨组织OPG mRNA明显低于CGRP组,而血清RANKL、IL1、IL-6、TNF-α水平和骨组织RANKL mRNA显著高于CGRP组(P0.01)。结论降钙素基因相关肽可明显提高维甲酸老年骨质疏松大鼠股骨BMD,其作用可能与抑制机体IL-1、IL-6、TNF-α水平从而调节OPG/RANKL平衡有关。     

慢性阻塞性肺疾病并骨质疏松患者血清IL-6、TNF-α水平的变化及其对OPG、RANKL表达的影响

目的 探讨慢性阻塞性肺疾病(COPD)并骨质疏松患者血清白细胞介素-6(IL-6)及肿瘤坏死因子α(TNF-α)水平的变化及其与OPG/RANK/RANKL系统的相关性。方法 选取2020年1月～2021年11月于我院就诊的男性稳定期COPD患者80例及同期健康体检者40例为研究对象。根据骨密度检测结果将COPD患者分为骨质疏松组(n=33)和非骨质疏松组(n=47),检测所有研究对象入组当天血清IL-6、TNF-α、核因子κB受体活化因子配体(RANKL)及骨保护素(OPG)水平并进行统计学分析。结果 (1) 80例COPD患者中33例合并骨质疏松,占比41%。与对照组相比,COPD组患者RANKL/OPG比值及IL-6、TNF-α、RANKL水平明显升高(均P<0.05);(2)与COPD非骨质疏松组患者相比,骨质疏松组患者RANKL/OPG比值及IL-6、TNF-α、RANKL水平明显升高,而FEV₁(%)、FEV₁/FVC(%)明显降低(均P<0.05);(3) COPD患者骨密度与血清IL-6、TNF-α、RANKL水平...     

冠心病患者血清OPG、sRANKL变化与冠脉病变程度的关系

目的探讨冠心病（CHD）患者血清骨保护素（OPG）、可溶性核因子κB受体活化因子配基（sRANKL）水平与冠脉病变程度的关系。方法选择心内科就诊患者80例,冠脉造影显示CHD 53例,其中单支病变组9例、双支病变组17例、多支病变组27例,正常对照组27例;采用ELLSA法检测各组血清OPG、sRANKL,并分析血清OPG、sRANKL水平与冠脉病变程度的相关性。结果与对照组比较,CHD患者血清OPG明显升高,且随冠脉病变程度增加而逐渐升高（P〈0.05）;血清sRANKL明显降低,且随冠脉病变程度增加而逐渐降低（P〈0.05）。结论CHD患者血清OPG升高、sRANKL降低,二者可作为CHD的预测因子,血清OPG水平与冠脉病变程度有关。     

血液透析患者骨保护素细胞核因子кB受体活化因子配体与动脉僵硬度的关系

目的探讨血液透析患者颈-股脉搏波速度(CFPWV)和颈-桡脉搏波速度(CRPWV)的变化及与骨保护素(OPG)、细胞核因子кB受体活化因子配体(sRANKL)系统的关系。方法对北京大学人民医院血液净化中心2006年6—10月40例血液透析患者采用酶联免疫吸附法测定血清OPG、sRANKL,PWV测定仪测定外周动脉僵硬度,X线平片检测腹主动脉、股动脉及桡动脉部位血管钙化,计算血管钙化积分。结果 25例(64.1%)患者存在不同程度的血管钙化,中重度钙化者较轻度钙化者血清OPG高[(342.50±171.53)ng/L对(206.21±137.88)ng/L,P=0.025]、OPG/sRANKL比值高(454.65±455.63比135.31±136.81,P=0.035),sRANKL比较差异无统计学意义[(0.10±0.08)pmol/L对(0.12±0.08)pmol/L]。血液透析患者CRPWV及CFPWV均较对照组增高,差异有统计学意义[(9.48±1.80)m/s对(8.58±1.29)m/s,P=0.043]和[(13.42±3.26)m/s对(10.07±1.76)m/s,P<0.01]。血OPG较对照组高[(235.12±154.33)ng/L对(93.00±44.10)ng/L,P=0.01],sRANKL两组比较,差异无统计学意义[(0.12±0.08)pmol/L对(0.16±0.08)pmol/L]。相关分析发现CRPWV与舒张压、sRANKL呈正相关(r=0.389、0.349,P=0.025、0.040),控制年龄、血压因素后CRPWV仍然与sRANKL呈正相关(r=0.381,P=0.029)。多元线性回归分析显示血磷、sRANKL及钙磷乘积是CRPWV的独立影响因素,年龄是CFPWV的独立影响因素。结论血液透析患者外周动脉僵硬度增加,sRANKL独立于年龄和血压影响血液透析患者动脉僵硬度。     

Adipocyte-secreted factors increase osteoblast proliferation and the OPG/RANKL ratio to influence osteoclast formation

Several studies have reported a positive relationship of the body fat mass and bone density. However, it is not clear whether adipocyte-derived signaling molecules directly act on osteoblasts or osteoclasts. Therefore, we investigated the effect of fat cell-secreted factors on the proliferation and differentiation of preosteoblasts and the molecular mechanisms involved.This stimulation led to an increased proliferation of MC3T3-E1 and primary preosteoblastic cells (2.8-fold and 1.5-fold, respectively; p < 0.0001), which could be reduced with inhibitors of protein tyrosine kinases, FGFR1 and PI3K. Concordantly, we found human adipocytes to secrete bFGF and bFGF to mimic the effect of adipocyte-secreted factors. The ratio of OPG/RANKL secretion in primary human preosteoblasts increased 9-fold (mRNA and protein) when stimulated with adipocyte-secreted factors. Moreover, osteoblasts which were prestimulated with adipocyte-secreted factors inhibited the formation of osteoclasts.In conclusion, human adipocytes secrete factors that directly act on preosteoblasts and alter their crosstalk with osteoclasts. These in vitro findings reflect the higher bone mass in obese people and attribute it to effects of adipocyte-secreted factors on bone formation.     

Effects of resistance and aerobic exercise on physical function, bone mineral density, OPG and RANKL in older women

This study compared the effects of a resistance training protocol and a moderate-impact aerobic training protocol on bone mineral density (BMD), physical ability, serum osteoprotegerin (OPG), and receptor activator of nuclear factor kappa B ligand (RANKL) levels. Seventy-one older women were randomly assigned to resistance exercise (RE), aerobic exercise (AE) or a control group (CON). Both interventions were conducted 3 times per week for 8 months. Outcome measures included proximal femur BMD, muscle strength, balance, body composition, serum OPG, and RANKL levels. Potential confounding variables included dietary intake, accelerometer-based physical activity (PA), and molecularly defined lactase nonpersistence. After 8 months, only RE group exhibited increases in BMD at the trochanter (2.9%) and total hip (1.5%), and improved body composition. Both RE and AE groups improved balance. No significant changes were observed in OPG and RANKL levels, and OPG/RANKL ratio. Lactase nonpersistence was not associated with BMD changes. No group differences were observed in baseline values or change in dietary intakes and daily PA. Data suggest that 8 months of RE may be more effective than AE for inducing favourable changes in BMD and muscle strength, whilst both interventions demonstrate to protect against the functional balance control that is strongly related to fall risk.     

阿托伐他汀钙对慢性心力衰竭患者血浆内皮素及心功能的影响

目的 观察阿托伐他汀钙对慢性心力衰竭患者血清内皮素（ET）及心功能的影响。方法选择98例慢性心力衰竭（NYHA分级Ⅱ～Ⅳ级）患者随机分成2组,治疗组（49例）和对照组（49例）,对照组给予强心、利尿、扩血管等常规治疗,治疗组在此基础上加用阿托伐他汀钙20mg,晚饭后顿服,治疗12月,治疗前后检测血清内皮素-1（ET-1）、总胆固醇（TC）、三酰甘油（TG）、低密度脂蛋白胆固醇（LDL—C）、高密度脂蛋白胆固醇（HDL-C）和左室射血分数（LVEF）情况并进行比较。结果 治疗组与对照组比较,治疗后血清ET-1、TC、TG、LDL．C均有不同程度的降低,左室射血分数（LVEF）则有明显提高。2组比较,差异有统计学意义（P〈0．05或P〈0．01）。结论阿托伐他汀钙能降低血浆ET-1水平,改善心脏功能,有益于慢性充血性心力衰竭的冶疗。     

Effects of titanium particle size on osteoblast functions in vitro and in vivo

The formation of titanium (Ti)-wear particles during the lifetime of an implant is believed to be a major component of loosening due to debris-induced changes in bone cell function. Radiographic evidence indicates a loss of fixation at the implant-bone interface, and we believe that the accumulation of Ti particles may act on the bone-remodeling process and impact both long- and short-term implant-fixation strengths. To determine the effects of various sizes of the Ti particles on osteoblast function in vivo, we measured the loss of integration strength around Ti-pin implants inserted into a rat tibia in conjunction with Ti particles from one of four size-groups. Implant integration is mediated primarily by osteoblast adhesion/focal contact pattern, viability, proliferation and differentiation, and osteoclast recruitment at the implant site in vivo. This study demonstrates the significant attenuation of osteoblast function concurrent with increased expression of receptor activator of nuclear factor kappaB ligand (RANKL), a dominant signal for osteoclast recruitment, which is regulated differentially, depending on the size of the Ti particle. Zymography studies have also demonstrated increased activities of matrix metalloproteinases (MMP) 2 and 9 in cells exposed to larger Ti particles. In summary, all particles have adverse effects on osteoblast function, resulting in decreased bone formation and integration, but different mechanisms are elicited by particles of different sizes.     

Role of receptor activator of nuclear factor-kappa B ligand (RANKL), osteoprotegerin and macrophage protein 1-alpha (MIP-1a) in monoclonal gammopathy of undetermined significance (MGUS)

The aim of this study was to evaluate the role of markers of bone remodelling, and osteoclast activation/function in patients with monoclonal gammopathy of undetermined significance (MGUS). We have measured serum levels of soluble RANKL (sRANKL), osteoprotegerin (OPG), macrophage inflammatory protein-1alpha (MIP-1alpha), markers of bone resorption [N-telopeptide of collagen type-I (NTX), and tartrate-resistant acid phosphatase isoform-5b (TRACP-5b)] and bone formation [bone-alkaline phosphatase (bALP)] in 40 MGUS patients. These parameters were compared with those of 42 newly diagnosed myeloma patients, and 45 healthy, gender- and age-matched controls. MGUS patients had elevated levels of NTX, sRANKL, and sRANKL/OPG ratio compared with controls (P < 0.0001). Furthermore, TRACP-5b, MIP-1alpha and NTX were decreased in patients with MGUS compared with myeloma patients (P < 0.001), while OPG and bALP were increased (P < 0.001). Serum levels of MIP-1alpha, as well as TRACP-5b, and sRANKL/OPG ratio were reduced, while bALP was increased in MGUS patients, even when compared with myeloma patients who had stage I/II disease. These results demonstrate that increased osteoclastogenesis leading to increased bone resorption is present in MGUS but seems to be compensated for by normal bone formation, which is absent in MM. Furthermore MIP-1alpha, bALP, and sRANKL/OPG may be useful tools for distinguishing between cases of MGUS and early myeloma.