IL—2,TNF—α和PGE2对破骨细胞性骨吸收的作用

从新生兔的四肢长骨中分离出破骨细胞，将其与大小约６ｍｍ×６ｍｍ、厚约１０μｍ的牛骨片共同培养。２４小时后，培养液中分别加入ＩＬ－２（５０Ｕ／ｍｌ，１００Ｕ／ｍｌ）；ＴＮＦ－α（１０￣（－１０）Ｍ，５×１０￣（－１０）Ｍ，１０￣（－９）Ｍ）；ＰＧＥ＿２（１００ｎｇ／ｍｌ）；并做空白对照。培养４０小时、６４小６寸及１周，利用相差显微镜计数吸收陷窝数，通过图像分析系统计算吸收陷窝表面积。结果表明：ＩＬ－２能促进破骨细胞性骨吸收：ＴＮＦ－α对分离破骨细胞性骨吸收无明显影响；ＰＧＥ＿２则对体外分离的破骨细胞具有抑制作用。     

破骨细胞骨吸收机制的研究进展

人体骨骼依赖于骨吸收和骨形成之间的动态平衡 ,当破骨细胞的骨吸收功能超过成骨细胞的骨形成作用后 ,这一平衡的失调将导致骨质疏松或骨质破坏。因妇女绝经、过量服用糖皮质激素等多种因素引起的骨质疏松 ,Ｐａｇｅｔ’ｓ病 ,以及癌症骨转移造成的骨破坏 ,都与破骨细胞异常活跃的分化增殖和骨吸收功能有关。因此 ,破骨细胞 (ｏｓｔｅｏｃｌａｓｔ,ＯＣ)是治疗上述疾病的靶细胞[1,2 ] 。1　破骨细胞分化形成的微环境ＯＣ是一种特殊类型的多核巨细胞 ,来源于ＣＤ3 4+ 的骨髓造血干细胞 ,其分化主要受骨髓基质细胞和成骨细胞所分泌的集落细胞…     

破骨细胞骨吸收机制研究进展

以绝经后骨量迅速下降为主要特征的绝经后骨质疏松症是生殖健康领域中的重要问题。破骨细胞 (osteoclast)作为骨吸收的主要细胞 ,对于骨量的变化具重要作用。因此 ,研究破骨细胞的生物学特性及骨吸收的机理对于预防和治疗骨质疏松症等代谢性骨病具有十分重要的意义。本综述着重论述破骨细胞的生物学特性及骨吸收的分子生物学机制和机理 ,抑制破骨细胞骨吸收的相关因素 ,以期进一步推动破骨细胞骨吸收功能的研究 ,加强骨质疏松等骨代谢疾病的治疗。一、破骨细胞的生物学特性破骨细胞来源于希腊文“Osteon”(骨 )和“klio”(破坏 )两词的组合…     

破骨细胞及其骨吸收调控研究进展

一、概述破骨细胞是一个高度分化的多核巨细胞,直接参与骨吸收,是骨组织吸收的主要功能细胞。破骨细胞的来源:由于长期以来对于破骨细胞(Osteoclast,OC)的来源问题一直不清楚,给研究工作带来许多困难,因而对临床各种骨疾患的诊断及其防治水平,也不可能进一步深入和提高。对于破骨细胞来源的认识,在本世纪40～70年代,普遍应用的经典理论为多潜能的骨源细胞学说,认为破骨细胞是由骨源细胞融合而成。直至70年代中期还认为OC与成骨细胞(OB)为共同的祖代来源。这种观点多年来一直是疑问,不能被证实,现已被否定。自80年代初开始,提出了OC来源…     

破骨细胞相关受体研究进展

人破骨细胞相关受体是一种细胞表面分子,属白细胞受体复合物编码的家族成员,广泛表达于破骨细胞、单核细胞、巨噬细胞、单核源树突状细胞等髓系来源细胞,与破骨细胞分化过程中的重要调控因子相互作用,参与破骨细胞分化,在骨代谢中发挥重要作用,受多种因素调节。同时,破骨细胞相关受体与Fc受体γ链特异性结合,调节免疫反应。     

应用颅骨-破骨细胞联合培养体系研究先天性成骨不全破骨细胞骨吸收活性

目的 先天性成骨不全(OI)的主要临床表现为骨矿化过程不良,骨量丢失,骨骼畸形和骨折.但是其发病机理,尤其在其骨再建过程中成骨细胞(OB)及破骨细胞(OC)的功能改变尚不清楚.本实验以先天性成骨不全小鼠模型,oim/oim为基础,应用破骨细胞-颅骨联合培养体系研究OB和OC两种细胞在骨再建过程中的功能改变和相互作用.方法 本实验采用小鼠颅骨(CAL)组织培养模型.本模型采用颅骨组织培养,利用颅骨中成骨细胞可以从颅骨片游离出到培养皿及颅骨表面,从而支持培养皿及颅骨表面前体破骨细胞分化成为成熟破骨细胞,并吸收颅骨产生吸收陷窝.本实验中,共2组颅骨-破骨细胞联合培养体系:(1) 对照组(WT)颅骨与对照破骨细胞(WTCAL-WTOC);(2) OI颅骨与OI破骨细胞(OICAL-OIOC).联合培养颅骨及骨髓组织14日后,以TRAP免疫组化染色方法识别破骨细胞,ALP免疫组化染色方法识别成骨细胞,计算OC/OB.破骨细胞骨吸收活性以颅骨表面骨吸收陷窝占颅骨表面百分比并除以培养系统中的破骨细胞数表达.结果 第14日,OICAL-OIOC组的破骨细胞数低于WTCAL-WTOC组(92.50+23.18/mm2 对比 379.00+ 136.53/mm2,P<0.01); OICAL-OIOC组的OC/OB明显低于WTCAL-WTOC组(0.68+0.57对比1.65+0.67,P<0.01);OICAL-OIOC组OI破骨细胞的吸收能力高于WTCAL-WTOC组(27.76+22.81对比7.32+5.09,P<0.001).结论 oim/oim小鼠破骨细胞-颅骨培养体系中破骨细胞的数目明显减少,成骨细胞支持破骨细胞分化能力减低;但其破骨细胞骨吸收活性明显增强,以代偿成骨细胞功能,维持骨再建过程中成骨过程及骨吸收过程的平衡.     

破骨细胞与骨吸收

骨吸收可发生于骨骼系统的各个部位．可见于全身性疾患与局部病变，骨骼肿瘤与骨囊肿，还可见于正常的生理性骨吸收，维持骨的生长、代谢平衡。骨吸收与破骨细胞相伴随，对破骨细胞的形态、结构、功能及来源的研究探讨，对各种骨疾病防治，具有重要的意义。     

TNF家族对假体周围组织中破骨细胞活性的调节

假体周围骨溶解是导致人工关节晚期松动的最重要原因.肿瘤坏死因子(TNF)家族成员RNAKL、TNF-α、FasL、TRAIL在破骨细胞分化、激活和凋亡调节中发挥重要作用.它们不仅参与调节生理性骨重建,也与病理状态下许多骨病的发生密切相关.该文就TNF家族成员对假体周围组织中破骨细胞分化、激活和凋亡的调节作用作一综述.     

TNF-α及TNF-α抗体对破骨细胞V-ATP酶的影响

目的研究不同浓度的TNF-α及TNF-α抗体对破骨细胞上V-ATP酶表达量的影响。方法体外诱导小鼠RAW264.7细胞分化为破骨细胞,通过抗酒石酸酸性磷酸酶染色检测破骨细胞生成情况。然后将破骨细胞分为对照组、TNF-α干预组及TNF-α抗体干预组,TNF-α干预组、TNF-α抗体干预组分别用低、中、高三种浓度的TNF-α、TNF-α抗体干预48 h。用实时荧光定量聚合酶链反应(real-time PCR)、Western blot检测破骨细胞V-ATP酶的mRNA和蛋白表达水平。结果 TRAP染色检测提示有多核破骨细胞生成。TNF-α处理组V-ATP酶mRNA表达水平显著高于对照组(P0.001);TNF-α抗体处理组V-ATP酶mRNA表达水平显著低于对照组(P0.001)。同时,TNF-α处理组V-ATP酶蛋白表达水平显著高于对照组(P0.05);TNF-α抗体处理组V-ATP酶蛋白表达水平显著低于对照组(P0.05)。结论 TNF-α可提高破骨细胞V-ATP酶的表达;TNF-α抗体可抑制破骨细胞V-ATP酶的表达。上述提示TNF-α可能通过提高破骨细胞V-ATP酶的表达从而增加破骨细胞的骨吸收作用。     

骨水泥颗粒促进肿瘤坏死因子α诱导的破骨细胞形成及其骨吸收作用

目的:验证骨水泥颗粒对肿瘤坏死因子α(TNFα)诱导的破骨细胞形成及其生物学活性的影响。方法:体外培养外周血单核细胞,对照组加入TNFα和白细胞介素-1α(IL-1α)及巨噬细胞克隆集落刺激因子(M-CSF),实验组并分别加入含有或不含有硫酸钙的骨水泥(PMMA±BaSO4)颗粒。对培养终末细胞作组织化学染色检测破骨细胞标志物抗酒石酸酸性磷酸酶(TRAP)的表达,并以象牙磨片上虫蚀样骨吸收陷窝的形成为指标检测破骨细胞的生物学活性;并比较各实验组中TRAP阳性多核细胞(multinucleatedcells,MNCs)及虫蚀样骨吸收陷窝形成时间的早晚。结果:各组TRAP阳性MNCs的数量无明显差异;PMMA±BaSO4组象牙磨片上骨吸收陷窝的面积均较对照组大,差异具有显著性(P<0.01);并且PMMA±BaSO4组TRAP阳性的MNCs及虫蚀样骨吸收陷窝的形成均较对照组早。结论:PMMA±BaSO4颗粒能够促进TNFα诱导的破骨细胞分化提早发生并促进其骨吸收活性。     

Dendritic cells at the osteo-immune interface: implications for inflammation-induced bone loss.

Within the past decade, the critical roles of T cells and T cell-mediated immunity in inflammation-induced osteoclastogenesis and subsequent bone loss have been extensively studied, thereby establishing the new paradigm of osteoimmunology. Therefore, dendritic cells (DCs), the most potent antigen-presenting cells, responsible for activation of na?ve T cells and orchestration of the immune response, became critically situated at the osteo-immune interface. Today, emerging new evidence suggests that DC may be directly involved in inflammation-induced osteoclastogenesis and bone loss, by acting as osteoclast (OC) precursors that can further develop into DC-derived OCs (DDOC) under inflammatory conditions. These findings have tremendous implications, because in addition to DC's important roles in regulating innate and adaptive immunity, a direct contribution by these cells to inflammation-induced bone loss may provide a promising therapeutic target not only for controlling inflammation but also for modulating bone destruction.     

Synergistic effects of green tea polyphenols and alphacalcidol on chronic inflammation-induced bone loss in female rats

Summary  

Studies suggest that green tea polyphenols (GTP) or alphacalcidol is promising agent for preventing bone loss. Findings that GTP supplementation plus alphacalcidol administration increased bone mass via a decrease of oxidative stress and inflammation suggest a significant role of GTP plus alphacalcidol in bone health of patients with chronic inflammation.     

Everolimus suppresses cancellous bone loss, bone resorption, and cathepsin K expression by osteoclasts

The proliferation inhibitor of the macrolide class, everolimus, is a drug shown to be effective in the prevention of organ transplant rejection and to have a potential in the treatment of rheumatoid arthritis and certain cancers. As these diseases or their current treatments are associated with bone loss, we examined the effect of everolimus on mouse and human bone cells in vitro and on bone in an ovariectomized (OVX) rat model. Everolimus potently inhibited primary mouse and human osteoclast activity in the pit assay (IC50 values of 0.6-4.0 nM), as well as osteoclast formation, measured as the number of tartrate-resistant acid phosphatase (TRAP) multinucleated cells (IC50 values of 7.7-10.5 nM). Inhibition of osteoblastic differentiation was also observed (IC50 value of 13.5 nM). As expected, everolimus inhibited proliferation of osteoclast precursors and stimulated apoptosis, albeit with insufficient potency and efficacy to explain inhibition of osteoclast activity. Thus, everolimus appeared to directly inhibit bone resorption, which is in accord with the detected inhibition of mRNA and protein expression of cathepsin K; the main collagen-degrading protease in osteoclasts. Despite the in vitro antiproliferative activity of everolimus and the observed inhibition of osteoblast differentiation, no detrimental effects were detected at different skeletal sites in mature OVX rats at doses up to 3 mg/kg/day. This everolimus dose also prevented the OVX-induced loss of cancellous bone by 60%, an effect predominantly associated with decreased osteoclast-mediated bone resorption, resulting in a partial preservation of the cancellous bone network. Everolimus inhibited S6 kinase 1 activity in rat blood cells, skin, and bone, at doses equivalent to those used for efficacy experiments in the OVX rat model, which demonstrated in vivo targeting of the expected molecular pathway. In conclusion, everolimus directly inhibits bone resorption by osteoclasts and thus could at least be neutral or protective for bone in vivo, which would favor its use in disease indications associated with bone loss.     

The origin of osteoclasts: An immunohistochemical study on macrophages and osteoclasts in embryonic rat bone

Summary The origin of osteoclasts was studied in embryonic rat bone primordia using a set of monoclonal antibodies (ED1, ED2, and ED3) that exclusively recognize monocytes and macrophages. ED1 recognizes monocytes and macrophages. Mononuclear phagocytes which were ED1 positive were found in the perichondrium/periosteum of developing bone. These cells started to infiltrate the primordia when the cartilage became hypertrophic. During bone formation, multinucleated ED1-positive cells with the morphological characteristics of osteoclasts were found in the developing bone marrow cavity and against the bone collar. The present findings support the notion that osteoclasts arise by fusion of mononuclear phagocytes derived from blood monocytes.     

The role of the macrophage in periprosthetic bone loss.

Aseptic loosening after total joint replacement remains the most common reason for long-term implant failure. Macrophages activated by submicron wear particles of the polyethylene liner used in joint replacement have been shown to be the source of periprosthetic bone loss. Understanding the role of material chemistry in macrophage activation and the subsequent effects that macrophage-derived enzymes play in the degradation of implanted biomaterials is key to developing methods for prolonging the lifespan of implantable materials.     

Longitudinal study of bone loss in the second metacarpal

Summary This longitudinal study was undertaken to ascertain the rate of bone loss and to identify aging, cohort and/or time effects on bone loss in male participants of the Baltimore Longitudinal Study of Aging. Hand-wrist radiographs were obtained from 1958–1981 and were evaluated for total width, medullary width, and length of the second metacarpal. Data were analyzed using an age-time matrix with 8-year intervals for three epochs and nine age groups. The bone measurements were analyzed in three perspectives (cross-sectional, longitudinal and time-series). The results demonstrate that there is both a cross-sectional and longitudinal loss of cortical bone with age in the second metacarpal. Furthermore, the results show that males lose approximately 14% of their cortical bone, at a rate of about 2% per decade, over the adult lifespan. The majority of this loss occurs between the ages of 45 and 69 and is due primarily to aging and is not an artifact of cohort differences or secular change.     

Multi-functional osteoclasts in matrix-based tissue engineering bone

The repair of bone defects, especially for the large segment of bone defects, has always been an urgent problem in orthopedic clinic and attracted researchers’ attention. Nowadays, the application of tissue engineering bone in the repair of bone defects has become the research hotspot. With the rapid development of tissue engineering, the novel and functional scaffold materials for bone repair have emerged. In this review, we have summarized the multi-functional roles of osteoclasts in bone remodeling. The development of matrix-based tissue engineering bone has laid a theoretical foundation for further investigation about the novel bone regeneration materials which could perform high bioactivity. From the point of view on preserving pre-osteoclasts and targeting mature osteoclasts, this review introduced the novel matrix-based tissue engineering bone based on osteoclasts in the field of bone tissue engineering, which provides a potential direction for the development of novel scaffold materials for the treatment of bone defects.     

Degradation of the organic phase of bone by osteoclasts: a secondary role for lysosomal acidification.

Osteoclasts degrade bone matrix by secretion of hydrochloric acid and proteases. We studied the processes involved in the degradation of the organic matrix of bone in detail and found that lysosomal acidification is involved in this process and that MMPs are capable of degrading the organic matrix in the absence of cathepsin K. INTRODUCTION: Osteoclasts resorb bone by secretion of acid by the vacuolar H+-adenosine triphosphatase (V-ATPase) and the chloride channel ClC-7, followed by degradation of the matrix, mainly collagen type I, by cathepsin K and possibly by matrix metalloproteinases (MMPs). However, the switch from acidification to proteolysis and the exact roles of both the ion transporters and the proteinases still remain to be studied. MATERIALS AND METHODS: We isolated CD14+ monocytes from human peripheral blood from either controls or patients with autosomal dominant osteopetrosis type II (ADOII) caused by defective ClC-7 function and cultured them in the presence of RANKL and macrophage-colony stimulating factor (M-CSF) to generate osteoclasts. We decalcified cortical bovine bone slices and studied the osteoclasts with respect to morphology, markers, and degradation of the decalcified matrix in the presence of various inhibitors of osteoclast acidification and proteolysis, using normal calcified bone as a reference. RESULTS: We found that ADOII osteoclasts not only have reduced resorption of the calcified matrix, but also 40% reduced degradation of the organic phase of bone. We found that both acidification inhibitors and cathepsin K inhibitors reduced degradation of the organic matrix by 40% in normal osteoclasts, but had no effect in the ADOII osteoclasts. Furthermore, we showed that inhibition of MMPs leads to a 70% reduction in the degradation of the organic bone matrix and that MMPs and cathepsin K have additive effects. Finally, we show that osteoclastic MMPs mediate release of the carboxyterminal telopeptide of type I collagen (ICTP) fragment in the absence of cathepsin K activity, and therefore, to some extent, are able to compensate for the loss of cathepsin K activity. CONCLUSIONS: These data clearly show that osteoclastic acidification of the lysosomes plays a hitherto nonrecognized role in degradation of the organic matrix. Furthermore, these data shed light on the complicated interplay between acidification dependent and independent proteolytic processes, mediated by cathepsin K and the MMPs, respectively.     

成骨细胞与破骨细胞间接共培养研究进展

在骨代谢过程中,成骨细胞形成新骨,破骨细胞吸收旧骨,一旦成骨细胞介导的骨基质形成和破骨细胞介导的骨吸收失衡,则会导致骨质疏松症等危害人类健康的疾病产生。因此,不同研究者致力于开发模拟体内环境的成骨细胞与破骨细胞体外共培养模型,以进行骨代谢相关疾病的研究。间接式共培养是通过物理方式将成骨细胞与破骨细胞分隔,使二者可以进行细胞间的交流而不接触,可以针对单一的细胞进行分析,在药物筛选及研究方面,具有高通量和经济便捷等独特的优势,本文对成骨细胞和破骨细胞的间接共培养技术进行归纳和总结。