1,25-(OH)2D3对去卵巢骨质疏松大鼠骨密度及OPG、RANKL表达的影响

目的:探讨1,25-(OH)2D3对去卵巢骨质疏松大鼠骨密度及OPG、RANKL表达的影响。方法选取6月龄雌性SD大鼠32只,随机分4组;空白组正常饲养,模型组制备去卵巢骨质疏松模型,假手术组按照模型组的流程给予开腹和缝线刺激,干预组在制备去卵巢骨质疏松模型的基础上给予1,25-(OH)2D3灌胃。分别于造模前后测定各组大鼠股骨BMD,并在造模最后一天取大鼠外周血和脊髓组织,采用Western Blotting检测OPG和RANKL的蛋白表达水平。结果:造模前,各组大鼠的体重和BMD无统计学差异(P0.05);造模后,与对照组相比,模型组大鼠体重显著升高,BMD显著降低;与模型组相比,干预组大鼠体重显著降低,BMD显著升高;各项组间差异均有统计学意义(P0.05)。与对照组相比,模型组OPG蛋白表达水平显著降低,假手术组无显著差异;与模型组相比,干预组大鼠OPG蛋白表达水平显著升高;RANKL变化趋势与OPG相反,且各项组间差异均有统计学意义(P0.05或P0.001)。结论:1,25-(OH)2D3能够改善雌激素降低引发的OPG/RANKL平衡失调,提高去卵巢骨质疏松大鼠的骨密度。     

胰岛素对2型糖尿病骨质疏松大鼠血清与骨OPG、RANKL表达的影响

目的:探讨胰岛素对2型糖尿病骨质疏松大鼠血清及骨OPG(osteoprotegerin)、RANKL(OPG receptor activator nuclear factork B)表达水平的影响。方法:以高脂高糖饲料喂养4周同时饮用3%果糖水导致胰岛素抵抗小鼠,再以小剂量链脲佐菌素(30mg/kg)腹腔注射1次,2周后诱导建立2型糖尿病小鼠模型。对照组动物则给予正常饲料及饮用水进行喂养。模型建立成功后,对模型2组大鼠进行胰岛素治疗,分别采用OPG和RANKLelisa试剂盒对正常动物模型和糖尿病动物模型血清和骨组织中OPG,RANKL含量进行比较分析,采用血糖分析仪对不同组动物的血糖进行比较分析,采用骨密度分析仪对动物的骨密度进行分析,了解高血糖对于骨密度及血清,骨组织中OPG,RANKL含量的影响以及胰岛素对高血糖骨质疏松造成的结果的影响。结果:相较于正常组大鼠,模型组大鼠血清及髂骨中OPG、血糖、糖化血红蛋白、髂骨密度表达显著下调(P0.05),而RANKL表达显著上调(P0.05),胰岛素处理的模型大鼠血清及骨中OPG含量较模型组大鼠显著升高,血清及骨组织中RANKL表达显著下调(P0.05)。结论:胰岛素能够显著降低2型糖尿病骨质疏松大鼠血清及骨组织中RANKL的表达,显著上调OPG的表达。     

基于OPG/RANK/RANKL系统比较研究前肢畸形WHBE兔骨代谢特征

目的利用OPG(osteoprotegerin)/RANK(receptor activator of NF-κB)/RANKL(receptor activator of NF-κB ligand)系统比较研究前肢畸形WHBE兔骨代谢特征。方法取WHBE兔、日本大耳白兔、前肢畸型WHBE兔各10只,分为3组,标记为HWR(healthy WHBE rabbit)、HJR(healthy Japanese rabbit)和FMWR(forelimb malformation WHBE rabbit)组。用X射线机所拍摄X-线片观察各组兔前肢尺桡部形状并测定平均灰度值;通过骨组织石蜡切片HE染色对前肢骨组织进行微观形态分析;采用荧光定量PCR法检测OPG、RANKL基因在肝脏中表达;采用酶联免疫法和免疫组化法分别测定OPG/RANK/RANKL蛋白在血清和骨组织中的表达。结果与HWR和HJR组比较,FMWR组兔前肢尺桡部呈异常弯曲状,骨皮质明显变薄,X-线片所示灰度值显著低于HWR组(P0.05)。FMWR组兔在肝脏RANKL基因表达水平和RANKL/OPG mRNA比值(P0.01),血清RANK、RANKL蛋白含量及RANKL/OPG比值(P0.05,P0.01),骨组织RANKL蛋白表达阳性指数及RANKL/OPG比值(P0.05,P0.01)等指标上均显著高于HWR组和HJR组。与HJR组比较,HWR组兔肝脏OPG和RANKL基因表达水平显著提高(P0.05,P0.01)。结论前肢畸形WHBE兔存在骨质量下降、骨组织受损现象,RANKL/OPG比值明显升高,骨代谢紊乱是其骨骼发生畸形的主要原因。与日本大耳白兔在RANKL基因表达水平上的品种差异可能是WHBE兔对前肢畸形易感的诱因。     

左归丸、右归丸对去卵巢骨质疏松模型大鼠的效用

本研究以去卵巢骨质疏松症模型大鼠为研究对象,采用比较分析与去卵巢骨质疏松症相关的多项因子的方法,试图探究左、右归丸的效应机理。将雌性SD大鼠随机分为空白组、假手术组、模型组(OVX组)、己烯雌酚组、左归丸组、右归丸组,每组12只。除空白组、假手术组外,将各组大鼠双侧卵巢切除制备绝经后骨质疏松症大鼠模型。造模一周后,分别给予各组相应的蒸馏水或药物,持续治疗12周。测定各组大鼠腰椎骨密度、血清钙、血清碱性磷酸酶(ALP)含量和大鼠胫骨骨髓中OPG、RANKL、Wnt1蛋白的表达量。与空白组、假手术组相比,模型组大鼠OPG、骨密度均显著下降(p0.01),而ALP、RANKL、Wnt1明显升高(p0.01);各给药组较OVX组,OPG、骨密度不同程度提高,ALP、RANKL、Wnt1则有不同程度降低(p0.05)。结果表明,左、右归丸能够抑制骨吸收,降低骨转化率,使骨形成和骨吸收趋于平衡,可有效防治去卵巢骨质疏松症模型大鼠的骨流失并改善骨组织形态,并且右归丸疗效优于左归丸;本研究为中医防治PMOP提供坚实的实验依据,并从分子水平揭示左、右归丸的治疗机理,推动了左、右归丸治疗PMOP作用机制的研究。     

OPG/RANKL/RANK系统与骨破坏性疾病

近年来发现的OPG/RANKL/RANK系统在破骨细胞生成中起着至关重要的作用,是骨骼生理研究领域的重大进展。成骨细胞、骨髓基质细胞、激活的T淋巴细胞表达RANKL,与破骨细胞前体细胞或成熟破骨细胞表面上的RANK结合后,促进破骨细胞的分化及骨吸收活性。成骨细胞及骨髓基质细胞分泌表达OPG可与RANKL竞争性结合,从而阻断RANKL与RANK之间的相互作用。体内多种激素或因子通过影响骨髓微环境内的OPG/RANKL比率来调节骨代谢。此外,乳腺上皮细胞表达有RANK,孕期在性激素的诱导下可表达RANKL,OPG/RANKL/RANK系统在孕期乳腺发育以及母体向胎儿的钙转运过程中发挥重要作用。阻断RANKL/RANK通路有望给骨质疏松、类风湿关节炎及癌症骨转移等骨破坏性疾病的治疗开辟新的途径。进一步研究应了解OPG/RANKL/RANK系统与其它信号传导途径的关系,重视骨骼、免疫及内分泌系统之间的相互作用。目前,开发与OPG功能相似或促进其表达的合成药物有可能成为具有良好经济效益和社会效益的产业。     

淫羊藿苷对小鼠骨溶解模型OPG/RANKL基因及其蛋白表达的影响

目的:研究不同剂量的淫羊藿苷对钛颗粒诱导小鼠骨溶解模型中OPG/RANKL基因及其蛋白表达的影响,探讨淫羊藿苷治疗关节置换术后骨溶解的作用机制.方法:取成年BALB/C小鼠40只,随机分为假手术组、阴性对照组、淫羊藿苷低剂量组及高剂量组,每组10只,除假手术组外,其余建立骨溶解模型后,各组按各自药物及剂量给予每日1次灌胃,共8周.停药次日取颅骨组织及外周血,运用real-time PCR及ELISA技术测定OPG/RANKL基因及其蛋白表达情况.结果:与阴性对照组相比,高剂量组OPG基因及蛋白表达显著上升(P＜0.01),RANKL基因及蛋白表达显著下降(P＜0.01);低剂量组无显著差异.结论:淫羊藿苷可以改变OPG/RANKL基因及蛋白表达量从而抑制骨溶解,这可能是淫羊藿苷治疗关节置换术后骨溶解的作用机制之一.     

RANKL/RANK/OPG信号通路对骨代谢和血管钙化作用机制的研究现状

核因子-κB受体活化因子配体(receptor activator of nuclear factor-kappa B ligand,RANKL)/核因子-κB受体活化因子(receptor activator of nuclear factor kappa B,RANK)/骨保护素(osteoprotegerin,OPG)信号通路是调节骨代谢过程中破骨细胞功能的重要通路。OPG能够与RANKL结合并阻止其与RANK结合,抑制破骨细胞生成从而抑制骨吸收,增加骨密度,改善骨质疏松。其中,RANKL/OPG的比值是骨吸收和骨形成平衡的关键。目前血管钙化已不再被看作是单纯的钙磷的被动沉积,而是由血管平滑肌细胞和内皮细胞主动参与的一种与骨形成相似的病理生理过程。在这个过程中,RANKL/RANK/OPG信号通路也起到重要作用。本文就RANKL/RANK/OPG信号通路在骨代谢和血管钙化中的作用机制进行了综述。     

温肾固疏方对PMOP大鼠骨密度及细胞因子表达的影响

通过观察温肾固疏方对去卵巢骨质疏松(PMOP)大鼠的骨密度及对白细胞介素-1β、肿瘤坏死因子-α、白细胞介素-6的血清含量和转化生长因子-β骨组织表达的影响,探讨其治疗骨质疏松的可能作用机制。将48只SPF级雌性SD大鼠分为6组:假手术组、模型组、雌激素组、温肾固疏方高、中、低剂量组。造模4周后开始给药,连续给药12周,酶联免疫法(ELISA)检测外周血清白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)含量;q RT-PCR法检测骨组织转化生长因子-β(TGF-β)m RNA含量。与假手术组相比较,去势模型组大鼠骨密度(BMD)、TGF-β mRNA显著降低(p0.05),而IL-1β、TNF-α、IL-6均显著升高(p0.01),符合绝经后骨质疏松症改变;干预治疗后,与模型组比较,温肾固疏方高、中剂量组椎骨BMD显著升高(p0.05),IL-1β、TNF-α、IL-6显著减少(p0.05),温肾固疏方高剂量组TGF-β mRNA显著增加(p0.05)。温肾固疏方治疗骨质疏松的作用机制可能与其下调IL-1β、TNF-α、IL-6等促炎细胞因子的表达,抑制骨吸收;同时上调TGF-β等抑炎细胞因子的表达,促进骨形成有关。     

ERα基因过表达对去卵巢骨质疏松小鼠骨密度及钙磷代谢的影响

目的: 探讨雌激素受体α(ERα)基因过表达对去卵巢骨质疏松小鼠骨代谢及钙磷代谢的影响,为靶向基因治疗骨质疏松症提供实验依据。方法: 选择SPF级雌性小鼠30只,随机分为假手术组、模型组和ERα过表达组,每组10只。采用双侧卵巢切除法制备绝经后骨质疏松小鼠模型,模型建立完成后,ERα过表达组通过椎体髓腔注射的方法转染携带小鼠ERα基因的重组腺病毒载体,模型组转染空载病毒,假手术组不作处理。实时荧光定量PCR(qRT-PCR)检测小鼠骨组织ERα基因表达;分别于造模后检测小鼠股骨骨密度(BMD);采用Micro-CT扫描测量骨小梁数量(Tb.N)、骨小梁厚度(Tb.Th)、骨小梁分离度(Tb.Sp)、骨体积分数(BV/TV),并进行股骨生物力学强度检测;采用全自动生化仪检测血清中钙(Ca)、磷(P)、骨钙素(BGP)、碱性磷酸酶(ALP)含量;采用免疫组化检测骨组织中基质金属蛋白酶的组织抑制剂1(TIMP-1)和单核细胞趋化蛋白-1(MCP-1)的蛋白表达水平。结果: 与假手术组相比,模型组小鼠骨组织ERα基因表达水平显著降低、BMD、BV/TV、Tb.Th、最大载荷、刚性系数、Ca和P降低,而Tb.Sp、BGP和ALP显著升高(P＜0.05);ERα过表达组小鼠骨组织ERα基因表达水平、BMD、BV/TV、Tb.Th、最大载荷、刚性系数、Ca和P较模型组小鼠显著上升;而Tb.Sp、BGP和ALP显著降低(P＜0.05)。与假手术组相比,模型组小鼠骨组织中TIMP-1平均光密度值显著降低而MCP-1平均光密度值升高,而ERα过表达组TIMP-1平均光密度值显著升高而MCP-1显著降低(P＜0.05)。结论: ERα基因过表达通过调节骨密度、骨参数、骨代谢、钙磷代谢指标及组织中TIMP-1和MCP-1的表达水平,改善骨质疏松。     

基于OPG/RANK/RANKL信号通路探讨铁筷子对CIA大鼠骨破坏的防护作用

目的 探讨铁筷子对胶原诱导性关节炎(collagen induced arthritis, CIA)模型大鼠的抗炎作用及对OPG/RANK/RANKL信号通路的影响。方法 雌性Wistar大鼠60只分为：正常组、模型组、阳性药物组(甲氨蝶呤,MTX)、低剂量组、中剂量组和高剂量组。采用胶原抗体诱导法于大鼠尾根部注射牛Ⅱ型胶原蛋白建立CIA大鼠模型,模型建立成功后进行灌胃给药,正常组：给予10 mL/(kg·d)生理盐水;模型组：给予10 mL/(kg·d)生理盐水;阳性药物组每次给予2.0 mL/(kg·d) MTX,每周3次;铁筷子低、中、高剂量组每次分别给予0.25 g/(kg·d)、 0.5 g/(kg·d)、1.0 g/(kg·d);连续灌胃治疗25 d。通过记录大鼠体重;观察大鼠足肿胀程度;大鼠踝关节炎指数评分;micro-CT观察踝关节骨组织病理改变;苏木素-伊红(HE)染色对大鼠踝关节骨组织和滑膜病理变化;抗酒石酸酸性磷酸酶(TRAP)染色法检测观察破骨细胞数量的改变;PCR检测骨保护素(OPG)、核因子-κB受体激活剂(RANK)、RANK配体(RANKL)、肿瘤坏死因...     

Changes in RANKL/OPG/RANK gene expression in peripheral mononuclear cells following treatment with estrogen or raloxifene

The RANKL/OPG/RANK pathway is the key mediator of osteoclastogenesis. Mononuclear cells may be implicated in post-menopausal osteoporosis. The effect of estrogen or raloxifene on bone resorption and the expression of RANKL/OPG/RANK in peripheral blood mononuclear cells (PBMCs) was examined. Twenty-nine women with post-menopausal osteoporosis were treated with estrogen (HRT) or raloxifene for 12 months. Bone mineral density (BMD) was measured at baseline and at 12 months at the spine and hip. Serum C-terminal telopeptide (CTX) and OPG were measured at baseline and at 1, 3, 6 and 12 months. PBMCs were isolated from 17 women and changes in RANKL, OPG and RANK mRNA were determined. The effects of estrogen or raloxifene in PBMCs in vitro were also assessed. BMD increased following treatment (lumbar spine % change mean [S.E.M.]: 4.3% [0.9], p<0.001). Serum CTX decreased (6 months: -43.7% [6.0], p<0.0001). Serum OPG declined gradually (12 months: -26.4% [4.4], p<0.001). RANKL, OPG and RANK gene expression decreased (6 months: RANKL 50.0% [24.8] p<0.001, OPG: 21.7% [28] p<0.001, RANK: 76.6% [10.2] p=0.015). Changes in OPG mRNA correlated with changes in BMD (r=-0.53, p=0.027) and CTX (r=0.7, p=0.0044). Down-regulation in RANKL, OPG, RANK mRNA and reduction in bone resorption was also seen in vitro. These results suggest that the expression of RANKL/OPG/RANK in PBMCs are responsive to the slowing in bone turnover/remodeling associated with treatment with estrogen or raloxifene. Further confirmatory studies are needed.     

利塞膦酸钠对去卵巢大鼠正畸牙齿移动期间破骨细胞中FAK蛋白表达的影响

目的:探讨利塞膦酸钠对去卵巢大鼠正畸牙齿移动期间破骨细胞中FAK蛋白表达的影响。方法:将30只雌性大鼠随机分为3组:假手术组、VOX组(卵巢切除+等量注射生理盐水)和利塞膦酸钠治疗组(切除卵巢+每3天腹膜内注射利塞膦酸钠),各10只。通过数字卡尺测量牙齿移动距离。通过蛋白质印迹检测FAK、I型胶原和整合素-β1蛋白表达水平。使用EXA-3000双能X射线BMD测量仪,测量左股骨BMD。通过RT-qPCR检测TRACP、RANKL和BMP-2 mRNA表达水平。结果:第1~3月时,与假手术组相比,VOX组大鼠体重和牙齿移动距离均增加(P<0.05),而与VOX组相比,利塞膦酸钠治疗组大鼠体重和牙齿移动距离均降低(P<0.05)。与假手术组相比,VOX组FAK、I型胶原和整合素-β1蛋白表达水平、tBMD、pBMD、mBMD和dBMD值以及TRACP、RANKL和BMP-2 mRNA水平均显著降低(P<0.05),而与假手术组和VOX组相比,利塞膦酸钠治疗组以上指标均显著增加(P<0.05)。结论:利塞膦酸钠通过调控整合素-β1/FAK信号通路,对去卵巢大鼠的骨吸收、骨质流失和骨强度降低有有效的抑制作用,可以预防和抑制卵巢切除引起的骨质疏松症的作用,这为骨质疏松症的临床治疗提供了新的依据。     

Imbalance of RANK,RANKL and OPG expression during tibial fracture repair in diabetic rats

To clarify the mechanisms of altered bone repair in the diabetic state, we investigated RANK, RANKL and OPG expression by immunohistochemistry and RT-PCR in the fracture sites of rats that were either healthy or made diabetic by alloxan. Histomorphometric analysis of the fracture site at 7 days after fracture revealed that diabetic rats (db) have significantly less hard tissue formation at the fracture site, compared to controls. The number of RANK, RANKL and OPG positive cells was decreased in the db group; however, the RANKL/OPG ratio was similar in controls and db at this time. At day 14, numbers of RANKL and OPG positive cells and the mRNA expression for these markers were higher in the control group than in db (P = 0.008). The RANKL/OPG ratio in the db group was greater than in controls. Our results demonstrate an imbalance of RANKL/OPG expression associated with diabetes that may contribute to the delay of fracture repair during the course of diabetes.     

巴戟天及其糖提取物对于体外培养成骨细胞OPG/RANKL基因系统表达的影响

目的:探讨巴戟天及多糖提取物对成骨细胞骨保护素(OPG)/核因子κB受体活化因子配体(RANKL)基因系统表达的影响。方法:取2~3天的SD大鼠5只分离原代成骨细胞,再取8周龄SD大鼠35只随机分为七组,对照组不进行处理,三组给予10 g/L、50 g/L、100 g/L巴戟天水灌胃,其余三组分别给予10 g/L、50 g/L、100 g/L巴戟天多糖灌胃,72 h后采用采用ELISA法测定培养液中OPG、RANKL及骨钙素的含量,采用MTT法检测不同浓度巴戟天水及多糖提取物对大鼠成骨细胞增殖的影响,采用荧光定量PCR检测OPG和RANKL mRNA表达情况;通过Westernblot检测OPG和RANKL蛋白表达水平。结果:巴戟天水及多糖提取物组A570nm、ALP活性、骨钙素含量、OPG/RANKL mRNA表达量、OPG和RANKL蛋白表达阳性密度均高于对照组(P0.05);A 570 nm、ALP活性、骨钙素含量、OPG/RANKL mRNA表达量、OPG和RANKL蛋白表达阳性密度均高于同等剂量的水提取物各组(P0.05);巴戟天多糖组中随着多糖剂量的升高A 570 nm、ALP活性、骨钙素含量、OPG/RANKL mRNA表达量、OPG和RANKL蛋白表达阳性密度,差异比较有统计学意义(P0.05)。结论:巴戟天水及多糖提取物均能促进体外培养成骨细胞的增殖,提高成骨细胞活性。     

Functions of RANKL/RANK/OPG in bone modeling and remodeling

The discovery of the RANKL/RANK/OPG system in the mid 1990s for the regulation of bone resorption has led to major advances in our understanding of how bone modeling and remodeling are regulated. It had been known for many years before this discovery that osteoblastic stromal cells regulated osteoclast formation, but it had not been anticipated that they would do this through expression of members of the TNF superfamily: receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG), or that these cytokines and signaling through receptor activator of NF-κB (RANK) would have extensive functions beyond regulation of bone remodeling. RANKL/RANK signaling regulates osteoclast formation, activation and survival in normal bone modeling and remodeling and in a variety of pathologic conditions characterized by increased bone turnover. OPG protects bone from excessive resorption by binding to RANKL and preventing it from binding to RANK. Thus, the relative concentration of RANKL and OPG in bone is a major determinant of bone mass and strength. Here, we review our current understanding of the role of the RANKL/RANK/OPG system in bone modeling and remodeling.     

OPG, RANK and RANK ligand expression in thyroid lesions

Receptor activator of NF-kappaB (RANK), RANK ligand (RANKL) and osteoprotegerin (OPG) play essential roles in bone metabolism. RANKL binds to RANK, which is expressed by osteoclasts whereas OPG acts as its decoy receptor blocking the RANK-RANKL interaction. OPG/RANK/RANKL are produced by variety of tissues including epithelial and mesenchymal cells. However, the role of RANKL/OPG in thyroid pathophysiology remains unclear. The aim of this study was to determine the expression pattern of RANK/RANKL/OPG in primary neoplastic thyroid lesions and in lymph node metastases. 27 specimens from total thyroidectomy were studied by immunohistochemistry: 9 papillary carcinomas (PC), 9 medullary carcinomas (MC), 9 macrovesicular adenomas (MA). Immunohistochemical evidence of RANKL was found in 30 % of MC, 22% of PC while RANKL has never been detected in PC. The expression of RANK is closely related to RANKL. OPG was restricted to the cytoplasm of epithelial in 1 MA and 1 MC. In contrast to pathological tissues, any expression of OPG/RANK/RANKL was detected in healthy thyroid tissue. This work reveals for the first time that OPG/RANK/RANKL are expressed in the pathological thyroid gland by follicular cells, by malignant parafollicular cells as well as in metastatic lymph node microenvironment. Thus OPG/RANK/RANKL molecular triad might play a role during pathogenesis of follicular and parafollicular tumors.     

The OPG/RANKL/RANK system in metabolic bone diseases

The OPG/RANKL/RANK cytokine system is essential for osteoclast biology. Various studies suggest that human metabolic bone diseases are related to alterations of this system. Here we summarize OPG/RANKL/RANK abnormalities in different forms of osteoporoses and hyperparathyroidism. Skeletal estrogen agonists (including 17beta-estradiol, raloxifene, and genistein) induce osteoblastic OPG production through estrogen receptor-alpha activation in vitro, while immune cells appear to over-express RANKL in estrogen deficiency in vivo. Of note, OPG administration can prevent bone loss associated with estrogen deficiency as observed in both animal models and a small clinical study. Glucocorticoids and immunosuppressants concurrently up-regulate RANKL and suppress OPG in osteoblastic cells in vitro, and glucocorticoids are among the most powerful drugs to suppress OPG serum levels in vivo. As for mechanisms of immobilization-induced bone loss, it appears that mechanical strain inhibits RANKL production through the ERK 1/2 MAP kinase pathway and up-regulates OPG production in vitro. Hence, lack of mechanical strainduring immobilization may favor an enhanced RANKL-to-OPG ratio leading to increased bone loss. As for hyperparathyroidism, chronic PTH exposure concurrently enhances RANKL production and suppresses OPG secretion through activation of osteoblastic protein kinase A in vitro which would favour increased osteoclastic activity. In sum, the capacity for OPG to antagonize the increases in bone loss seen in many rodent models of metabolic bone disease implicates RANKL/OPG imbalances as the likely etiology and supports the potential role for a RANKL antagonist as a therapeutic intervention in these settings.