Transcriptional reprogramming during human osteoclast differentiation identifies regulators of osteoclast activity

Enhanced osteoclastogenesis and osteoclast activity contribute to the development of osteoporosis,which is characterized by increased bone resorption and inadequate bone formation.As novel antiosteoporotic therapeutics are needed,understanding the genetic regulation of human osteoclastogenesis could help identify potential treatment targets.This study aimed to provide an overview of transcriptional reprogramming during human osteoclast differentiation.Osteoclasts were differentiated from CD14+monocytes from eight female donors.RNA sequencing during differentiation revealed 8980 differentially expressed genes grouped into eight temporal patterns conserved across donors.These patterns revealed distinct molecular functions associated with postmenopausal osteoporosis susceptibility genes based on RNA from iliac crest biopsies and bone mineral density SNPs.Network analyses revealed mutual dependencies between temporal expression patterns and provided insight into subtype-specific transcriptional networks.The donor-specific expression patterns revealed genes at the monocyte stage,such as filamin B(FLNB)and oxidized low-density lipoprotein receptor 1(OLR1,encoding LOX-1),that are predictive of the resorptive activity of mature osteoclasts.The expression of differentially expressed G-protein coupled receptors was strong during osteoclast differentiation,and these receptors are associated with bone mineral density SNPs,suggesting that they play a pivotal role in osteoclast differentiation and activity.The regulatory effects of three differentially expressed G-protein coupled receptors were exemplified by in vitro pharmacological modulation of complement 5 A receptor 1(C5AR1),somatostatin receptor 2(SSTR2),and free fatty acid receptor 4(FFAR4/GPR120).Activating C5AR1 enhanced osteoclast formation,while activating SSTR2 decreased the resorptive activity of mature osteoclasts,and activating FFAR4 decreased both the number and resorptive activity of mature osteoclasts.In conclusion,we report the occurrence of transcriptional reprogramming during human osteoclast differentiation and identified SSTR2 and FFAR4 as antiresorptive G-protein coupled receptors and FLNB and LOX-1 as potential molecular markers of osteoclast activity.These data can help future investigations identify molecular regulators of osteoclast differentiation and activity and provide the basis for novel antiosteoporotic targets.

CD97 inhibits osteoclast differentiation via Rap1a/ERK pathway under compression

Acceleration of tooth movement during orthodontic treatment is challenging, with osteoclast-mediated bone resorption on the compressive side being the rate-limiting step. Recent studies have demonstrated that mechanoreceptors on the surface of monocytes/macrophages, especially adhesion G protein-coupled receptors (aGPCRs), play important roles in force sensing.However, its role in the regulation of osteoclast differentiation remains unclear. Herein, through single-cell analysis, we revealed that CD97, a novel mechanosensitive aGPCR, was expressed in macrophages. Compression upregulated CD97 expression and inhibited osteoclast differentiation;while knockdown of CD97 partially rescued osteoclast differentiation. It suggests that CD97 may be an important mechanosensitive receptor during osteoclast differentiation. RNA sequencing analysis showed that the Rap1a/ERK signalling pathway mediates the effects of CD97 on osteoclast differentiation under compression. Consistently, we clarified that administration of the Rap1a inhibitor GGTI298 increased osteoclast activity, thereby accelerating tooth movement. In conclusion,our results indicate that CD97 suppresses osteoclast differentiation through the Rap1a/ERK signalling pathway under orthodontic compressive force.

New insights into inflammatory osteoclast precursors as therapeutic targets for rheumatoid arthritis and periodontitis

Rheumatoid arthritis(RA)and periodontitis are chronic inflammatory diseases leading to increased bone resorption.Preventing this inflammatory bone resorption is a major health challenge.Both diseases share immunopathogenic similarities and a common inflammatory environment.The autoimmune response or periodontal infection stimulates certain immune actors,leading in both cases to chronic inflammation that perpetuates bone resorption.Moreover,RA and periodontitis have a strong epidemiological association that could be explained by periodontal microbial dysbiosis.This dysbiosis is believed to be involved in the initiation of RA via three mechanisms.(i)The dissemination of periodontal pathogens triggers systemic inflammation.(ii)Periodontal pathogens can induce the generation of citrullinated neoepitopes,leading to the generation of anti-citrullinated peptide autoantibodies.(iii)Intracellular danger-associated molecular patterns accelerate local and systemic inflammation.Therefore,periodontal dysbiosis could promote or sustain bone resorption in distant inflamed joints.Interestingly,in inflammatory conditions,the existence of osteoclasts distinct from“classical osteoclasts”has recently been reported.They have proinflammatory origins and functions.Several populations of osteoclast precursors have been described in RA,such as classical monocytes,a dendritic cell subtype,and arthritis-associated osteoclastogenic macrophages.The aim of this review is to synthesize knowledge on osteoclasts and their precursors in inflammatory conditions,especially in RA and periodontitis.Special attention will be given to recent data related to RA that could be of potential value in periodontitis due to the immunopathogenic similarities between the two diseases.Improving our understanding of these pathogenic mechanisms should lead to the identification of new therapeutic targets involved in the pathological inflammatory bone resorption associated with these diseases.

Propionate and butyrate attenuate macrophage pyroptosis and osteoclastogenesis induced by CoCrMo alloy particles

Background:Wear particles-induced osteolysis is a major long-term complication after total joint arthroplasty.Up to now,there is no effective treatment for wear particles-induced osteolysis except for the revision surgery,which is a heavy psychological and economic burden to patients.A metabolite of gut microbiota,short chain fatty acids(SCFAs),has been reported to be beneficial for many chronic inflammatory diseases.This study aimed to investigate the therapeutic effect of SCFAs on osteolysis.Methods:A model of inflammatory osteolysis was established by applying CoCrMo alloy particles to mouse calvarium.After two weeks of intervention,the anti-inflammatory effects of SCFAs on wear particle-induced osteolysis were evaluated by micro-CT analysis and immunohistochemistry staining.In vitro study,lipopolysaccharide(LPS)primed bone marrow-derived macrophages(BMDMs)and Tohoku hospital pediatrics-1(THP-1)macrophages were stimulated with CoCrMo particles to activate inflammasome in the presence of acetate(C2),propionate(C3),and butyrate(C4).Western blotting,enzyme-linked immunosorbent assay,and immunofluorescence were used to detect the activation of NLRP3 inflammasome.The effects of SCFAs on osteoclasts were evaluate by qRT-PCR,Western blotting,immunofluorescence,and tartrate-resistant acid phosphatase(TRAP)staining.Additionally,histone deacetylase(HDAC)inhibitors,agonists of GPR41,GPR43,and GPR109A were applied to confirm the underlying mechanism of SCFAs on the inflammasome activation of macrophages and osteoclastogenesis.Results:C3 and C4 but not C2 could alleviate wear particles-induced osteolysis with fewer bone erosion pits(P<0.001),higher level of bone volume to tissue volume(BV/TV,P<0.001),bone mineral density(BMD,P<0.001),and a lower total porosity(P<0.001).C3 and C4 prevented CoCrMo alloy particles-induced ASC speck formation and nucleationinduced oligomerization,suppressing the cleavage of caspase-1(P<0.05)and IL-1β(P<0.05)stimulated by CoCrMo alloy particles.C3 and C4 also inhibited the generation of gasdermin D-N-terminal fragment(GSDMD-NT)to regulate pyroptosis.Besides,C3 and C4 have a negative impact on osteoclast differentiation(P<0.05)and its function(P<0.05),affecting the podosome arrangement and morphologically normal podosome belts formation.Conclusions:Our work showed that C3 and C4 are qualified candidates for the treatment of wear particle-induced osteolysis.

Glycobiology in osteoclast differentiation and function

Glycans,either alone or in complex with glycan-binding proteins,are essential structures that can regulate cell biology by mediating protein stability or receptor dimerization under physiological and pathological conditions.Certain glycans are ligands for lectins,which are carbohydrate-specific receptors.Bone is a complex tissue that provides mechanical support for muscles and joints,and the regulation of bone mass in mammals is governed by complex interplay between bone-forming cells,called osteoblasts,and bone-resorbing cells,called osteoclasts.Bone erosion occurs when bone resorption notably exceeds bone formation.Osteoclasts may be activated during cancer,leading to a range of symptoms,including bone pain,fracture,and spinal cord compression.Our understanding of the role of protein glycosylation in cells and tissues involved in osteoclastogenesis suggests that glycosylation-based treatments can be used in the management of diseases.The aims of this review are to clarify the process of bone resorption and investigate the signaling pathways mediated by glycosylation and their roles in osteoclast biology.Moreover,we aim to outline how the lessons learned about these approaches are paving the way for future glycobiology-focused therapeutics.

IgSF11-mediated phosphorylation of pyruvate kinase M2 regulates osteoclast differentiation and prevents pathological bone loss

Osteoclasts are primary bone-resorbing cells,and receptor-activated NF-k B ligand(RANKL)stimulation is the key driver of osteoclast differentiation.During late-stage differentiation,osteoclasts become multinucleated and enlarged(so-called“maturation”),suggesting their need to adapt to changing metabolic demands and a substantial increase in size.Here,we demonstrate that immunoglobulin superfamily 11(Ig SF11),which is required for osteoclast differentiation through an association with the postsynaptic scaffolding protein PSD-95,regulates osteoclast differentiation by controlling the activity of pyruvate kinase M isoform2(PKM2).By using a system that directly induces the activation of Ig SF11 in a controlled manner,we identified PKM2 as a major Ig SF11-induced tyrosine-phosphorylated protein.Ig SF11 activates multiple Src family tyrosine kinases(SFKs),including c-Src,Fyn,and Hc K,which phosphorylate PKM2 and thereby inhibit PKM2 activity.Consistently,Ig SF11-deficient cells show higher PKM2activity and defective osteoclast differentiation.Furthermore,inhibiting PKM2 activities with the specific inhibitor Shikonin rescues the impaired osteoclast differentiation in Ig SF11-deficient cells,and activating PKM2 with the specific activator TEPP46 suppresses osteoclast differentiation in wild-type cells.Moreover,PKM2 activation further suppresses osteoclastic bone loss without affecting bone formation in vivo.Taken together,these results show that Ig SF11 controls osteoclast differentiation through PKM2 activity,which is a metabolic switch necessary for optimal osteoclast maturation.

Invasive breast carcinoma with osteoclast-like stromal giant cells:A case report

BACKGROUND Invasive breast carcinoma with osteoclast-like stromal giant cells(OGCs) is an extremely rare morphology of breast carcinomas.To the best of our knowledge,the most recent case report describing this rare pathology was published six years ago.The mechanism controlling the development of this unique histological formation is still unknown.Further,the prognosis of patients with OGC involvement is also controversial.CASE SUMMARY We report the case of a 48-year-old woman,who presented to the outpatient department with a palpable,growing,painless mass in her left breast for about one year.Sonography and mammography revealed a 26.5 mm ×18.8 mm asymmetric,lobular mass with circumscribed margin and the Breast Imaging Reporting and Data System was category 4C.Sono-guided aspiration biopsy revealed invasive ductal carcinoma.The patient underwent breast conserving surgery and was diagnosed with invasive breast carcinoma with OGCs,grade Ⅱ,with intermediate grade of ductal carcinoma in situ(ER:80%,3+,PR:80%,3+,HER-2:negative,Ki 67:30%).Adjuvant chemotherapy and post-operation radiotherapy were initiated thereafter.CONCLUSION As a rare morphology of breast cancer,breast carcinoma with OGC occurs most often in relatively young women,has less lymph node involvement,and its occurrence is not racedependent.

Effects of acupotomy on the activity of osteoclasts and osteoblasts in the subchondral bone of rabbits with early and mid-stage knee osteoarthritis models

Objective:To investigate whether acupotomy could inhibit subchondral bone remodeling in knee osteoarthritis(KOA)rabbits by regulating the activity of osteoblasts and osteoclasts.Methods:KOA rabbits were prepared by immobilization for 6 and 9 weeks by Videman method.Nine groups of rabbits(control,6 weeks and 9 weeks model,6 weeks and 9 weeks acupotomy,6 weeks and 9 weeks electroacupuncture,and 6 weeks and 9 weeks drug groups)received acupotomy,electroacupuncture and risedronate sodium intervention,respectively,for 3 weeks.Results:Acupotomy can inhibit the activity of osteoclasts and osteoblasts in subchondral bone by reducing the proteins expression of cathepsin K(CK)and tartrate-resistant acid phosphatase(TRAP)and decreasing the proteins expression of osteocalcin(OCN)and alkaline phosphatase(ALP),to intercept the abnormal bone resorption and bone formation of subchondral bone in 6-week and 9-week immobilization-induced KOA rabbits.Conclusion:These findings indicated that acupotomy may be more advantageous than risedronate sodium intervention in modulating subchondral bone remodeling in KOA rabbits,especially in 9-week immobilization-induced KOA rabbits.

Research progress of bone sialoprotein in osteoclast differentiation and bone resorption

Bone sialoprotein(BSP)is an important non-collagen extracellular matrix protein(EMC)that promotes bone formation and induces bone resorption.BSP is secreted by odontoblasts,it plays an important role in cementum,alveolar bone formation and mineralization,and periodontal function.Bone resorption is controlled by a complex molecular network,and BSP can promote osteoclast differentiation and bone resorption.It is also associated with the metastasis of a range of malignancies.Osteoclasts(OC)are thought to be the only cells involved in bone resorption and play an important role in bone formation and late developmental remodeling.Osteoporosis and periodontal disease are caused by excessive bone resorption.This article will summarize the osteoclasts differentiation,the biological function of bone resorption,and explore the progress of the prevention and treatment of the related bone resorption diseases such as osteoporosis and periodontal disease through the regulation of osteoclasts.

miR-483-5p regulates osteoclast generation by targeting Timp2

Objective:To investigate whether miR-483-5p regulates osteoclast generation by targeting Timp2.miR-483-5p can promote osteoclast differentiation and bone destruction.Methods:Target genes of miR-483-5p were predicted by miRNAs target gene prediction software TargetScan8.0,and wild type and mutant 3'UTR plasmids were constructed.Dual luciferase reporter genes were used to verify whether target genes had a targeted regulatory relationship with miR-483-5p.Western blotting was used to detect the corresponding changes in the expression level of target protein after adjusting the level of miR-483-5p in cells.Cells were transfected or infected with target gene siRNA or target protein lentivirus,and TRAP staining and q-PCR assays were performed.In addition,for osteoclast induction experiment,RAW264.7 cells were co-transfected with ago-miR-483-5p and target protein-overexpressed lentiviruses q-PCR and TRAP staining were performed respectively.Results:Bioinformatics software was used to predict the target gene of miR-483-5p,and the Timp2 gene was found to regulate osteoclasts,and the dual luciferase reporter detection system found that miR-483-5p could be associated with the 3-UTR of the predicted target gene Timp2 gene.There are complementary loci and targeted regulatory relationship between them.Subsequently,we upregulated miR-483-5p in RAW264.7 cells to reduce the expression of Timp2.Compared with the normal group,the number of osteoclasts and the expression of osteoclast-specific genes increased significantly after the induction of Timp2 in knockdown cells.After co-transfection of target gene and miR-483-5p into cells,the number of osteoclasts and the expression of specific genes decreased significantly compared with the normal group.Conclusion:Timp2 is a downstream target gene of miR-483-5p and is involved in and inhibits osteoclast generation.

三七有效成分调控激素性股骨头坏死的相关信号通路

背景:激素性股骨头坏死是骨科领域难治和难愈性疾病,尚无确切研究观点完整解释其病理机制。随着三七有效成分干预多种疾病相关信号通路的研究增加,三七有效成分通过调控激素性股骨头坏死相关信号通路治疗该病逐渐成为时下研究热点。目的:系统总结分析近年来激素性股骨头坏死病理机制研究文献和三七有效成分调控该病相关信号通路的相关文献内容,为后续研究三七有效成分治疗该病提供参考。方法:检索中国知网及万方数据库,中文检索词为“糖皮质激素,激素性股骨头坏死,病理机制,信号通路,三七,有效成分”等;检索PubMed数据库,英文检索词为”Glucocorticoid,steroid associated necrosis of the femoral head,Pathological mechanism,signaling pathway,Panax notoginseng,active ingredient”等,筛选激素性股骨头坏死病理机制相关文献和三七有效成分调控激素性股骨头坏死相关信号通路文献,最终共纳入63篇文献。结果与结论:①三七主要成分包括三七总皂苷、人参皂苷、三七皂苷、槲皮素和山柰酚等。②在调控相关通路方面,三七总皂苷、人参皂苷Rb1和槲皮素作用于转化生长因子β/骨形态发生蛋白通路,能促进骨修复和血管新生;三七总皂苷、人参皂苷CK和山柰酚作用于Wnt/β-catenin通路,可促进成骨分化和脂质代谢;三七总皂苷及三七皂苷R1/R2作用于MAPK通路,抑制破骨和促进骨修复;三七总皂苷、人参皂苷Rb2及槲皮素作用于RANKL/RANK/骨保护蛋白通路,可抑制破骨增殖并促进成骨分化;三七总皂苷、槲皮素及山柰酚作用于缺氧诱导因子1α通路,能修复血管损伤和促进成骨。③三七皂苷R1、槲皮素联合羟基磷灰石纳米颗粒、三七总皂苷联合聚乙烯-L-乳酸等生物材料治疗激素性股骨头坏死具有良好的研究前景。④三七有效成分可通过多种机制调控激素性股骨头坏死相关信号通路,对该病起到积极的干预作用,但目前相关研究深度和广度不足,未来应基于现有的机制研究,深入探究三七调控该病不同通路的具体机制及通路间相互作用,将有利于运用三七有效成分治疗激素性股骨头坏死的多元发展。

中医药通过作用破骨细胞调控治疗绝经后骨质疏松研究进展

绝经后骨质疏松(PMOP)是绝经后女性由于破骨细胞的骨吸收和成骨细胞的骨形成失衡而引起的常见骨性疾病,其临床表现主要以活动受限,浑身疼痛甚至骨脆性增加易骨折为主。临床上我们常选用西医治疗为首选方法,但随着大家对中医的了解加深,中医在治疗绝经后骨质疏松上的优势逐渐被发现。现重点对近几年研究的中药及其复方作用破骨细胞来防治绝经后骨质疏松的机制加以归纳总结,为临床防治绝经后骨质疏松症提供新思路与方法,并为后续中医药在绝经后骨质疏松上有更好的运用提出展望。

龟板抑制破骨分化改善骨质疏松性骨折

目的基于网络药理学和实验验证探讨龟板(plastrum testudinis,PT)治疗骨质疏松性骨折(osteoporotic fracture,OF)的潜在机制。方法借助BATMAN数据库得到PT成分及其对应靶标,检索GeneCards、OMIM数据库获得OF相关靶点,在STRING数据库输入交集靶点得到蛋白互作(protein-protein interaction,PPI)信息,借助Cytoscape3.7.2软件进行PPI网络及“龟板-活性成分-靶标-骨质疏松性骨折”网络的构建,使用Cytoscape3.7.2软件、R软件进行GO功能富集分析及KEGG通路富集分析。此外,为了验证网络药理学研究结果的可靠性,还进行体内实验验证龟板改善OF的作用,并通过体外实验探究了龟板干预下的人外周血单核细胞(human peripheral blood monocytes,HPBMs)表型。结果获得龟板6个活性成分,342个作用靶标,其中与OF相关靶标34个,GO功能富集分析共有802个结果(P<0.05),KEGG富集分析有67个结果,其中相关信号通路有22条(P<0.05),主要涉及TNF、MAPK、Estrogen、NF-κB等信号通路。值得一提的是,体内实验证实龟板可有效治疗OF模型大鼠的骨缺损;体外实验发现龟板能抑制RANKL诱导的HPBMs破骨分化。结论龟板可能通过多种化合物、靶点和通路调节炎症反应、激素代谢及细胞周期来治疗OF,其中抑制破骨分化可能是龟板抗骨质疏松性骨折的重要机制。

miR-155/瘦素受体/AMPK轴在结核菌素诱导破骨细胞形成中的作用及机制

背景:破骨细胞异常活化在脊柱结核骨质破坏中起重要作用。在骨质疏松发病过程中,敲低miR-155通过增加瘦素受体的表达来激活磷酸腺苷依赖的蛋白激酶(AMP-dependent protein kinase,AMPK),进而抑制破骨细胞分化及骨吸收。但miR-155/瘦素受体/AMPK轴在脊柱结核骨质破坏中的作用尚不清楚。目的:研究miR-155/瘦素受体/AMPK轴在结核菌素诱导破骨细胞形成中的作用及机制。方法:培养单核巨噬细胞RAW264.7细胞,用不同浓度(1.0,2.5,5.0,10.0 IU/mL)结核菌素处理,转染阴性对照序列或miR-155抑制物、阴性对照siRNA序列或瘦素受体siRNA序列。采用抗酒石酸酸性磷酸酶染色检测破骨细胞数量,荧光定量PCR检测miR-155 mRNA表达,Western blot检测瘦素受体、p-AMPK蛋白表达,双荧光素酶报告基因验证miR-155靶向瘦素受体。结果与结论:①与对照组比较,2.5,5.0,10.0 IU/mL结核菌素组破骨细胞数量、miR-155 mRNA表达水平明显增加,瘦素受体、p-AMPK蛋白表达水平明显降低(P<0.05);②与阴性对照+5.0 IU/mL结核菌素组比较,miR-155抑制物+5.0 IU/mL结核菌素组破骨细胞数量、miR-155 mRNA表达水平明显降低,瘦素受体、p-AMPK蛋白表达水平明显增加(P<0.05);③与阴性对照组比较,miR-155抑制物组瘦素受体野生型双荧光素酶报告基因的荧光活力增加,miR-155模拟物组瘦素受体野生型双荧光素酶报告基因的荧光活力降低(P<0.05);④与阴性对照siRNA+miR-155抑制物+5.0 IU/mL结核菌素组比较,瘦素受体siRNA+miR-155抑制物+5.0 IU/mL结核菌素组miR-155 mRNA表达水平无明显变化(P>0.05),破骨细胞数量明显增加,瘦素受体、p-AMPK蛋白表达水平明显降低(P<0.05);⑤结果表明,结核菌素通过增加miR-155表达抑制下游瘦素受体表达及AMPK激活,进而诱导破骨细胞形成。

Toll样受体对成骨及破骨细胞功能的调节

背景:Toll样受体是一类重要的模式识别受体,通过识别特定的分子模式在病原体免疫、细胞因子合成等方面具有重要功能。既往的研究发现,不同种类的骨组织细胞同样表达Toll样受体。激活或抑制Toll样受体可通过多种途径对成骨与破骨细胞功能造成显著影响。目的:总结Toll样受体在成骨及破骨细胞中的表达及作用途径,以进一步阐明生理及病理状态下Toll样受体参与调控的生物学机制。方法:检索截至2022年12月的PubMed、中国知网等文献数据库中的相关文献,中文检索词为“Toll样受体,成骨细胞,破骨细胞,间充质干细胞,巨噬细胞,细胞因子,信号通路”,英文检索词为“toll-like receptor,osteoblast,osteoclast,mesenchymal stem cells,macrophage,cytokine,signaling pathway”,并根据研究需要确立相应的标准,对最终所得文献进行筛选。结果与结论:①Toll样受体可通过激活相关信号通路直接调节成骨、破骨细胞分化;②Toll样受体的激活诱导细胞因子的产生,发挥调节效应;③Toll样受体的激活能够对成骨、破骨细胞的生存及迁移能力产生影响;④在某些疾病及病理环境中,成骨及破骨细胞中的Toll样受体被激活,参与细胞间的相互作用。

藤黄健骨胶囊对PMOP大鼠RANKL/c-Fos/NFATc1通路的影响

目的探讨免疫调节分子IL-33对绝经后骨质疏松症(postmenopausal osteoporosis,PMOP)模型鼠RANKL/c-Fos/NFATc1信号轴的调控作用及藤黄健骨胶囊(Tenghuang Jiangu capsule,TJC)的干预机制。方法构建PMOP大鼠模型,设置假手术组、PMOP模型组、阳性对照组(0.09 mg/kg)和TJC高、中、低剂量组(0.36、0.18、0.09 g/kg),灌胃给药,每天1次,持续8周。从大鼠末次给药后体质量、骨密度(bone mineral density,BMD)及股骨组织微结构等方面评价TJC的疗效;通过ELISA分析TJC对大鼠血清免疫调节因子IL-33、IL-1、IL-31变化;运用qPCR和Western blotting分析TJC对大鼠股骨OPG、RANKL、RANK、c-Fos、NFATc1表达量的影响。结果与假手术组相比,PMOP模型组大鼠的体质量、骨髓脂肪组织相对面积(relative area of bone marrow adipose tissue,BMAT),IL-1、IL-31变化,RANKL、RANK、c-Fos、NFATc1的表达均出现了明显升高的趋势,而BMD、IL-33变化、OPG的表达则出现了明显下降的趋势(P<0.01);与PMOP模型组相比,TJC高剂量组大鼠体质量出现显著下降趋势、IL-33变化出现显著升高趋势(P<0.01),TJC中、高剂量组大鼠BMAT、RANK的表达出现显著下降趋势、OPG的表达出现显著升高趋势(P<0.05或P<0.01),TJC各剂量组大鼠IL-1、IL-31变化,RANKL、c-Fos、NFATc1出现显著降低趋势,BMD出现显著增加趋势(P<0.05或P<0.01)。结论TJC能够提高PMOP大鼠免疫调控分子IL-33含量,抑制免疫调控分子IL-1、IL-31含量和破骨细胞分化标志分子NFATc1的表达,其机制可能与RANKL/c-Fos/NFATc1抑制骨代谢通路密切相关。

主要组织相容性复合物Ⅱ类分子与绝经后骨质疏松症的相关性

绝经后骨质疏松症(postmenopausal osteoporosis,PMOP)是由绝经期雌激素缺乏引起的骨代谢紊乱相关的全身性骨骼疾病。主要组织相容性复合体Ⅱ类分子(major histocompatibility complex ClassⅡmolecules,MHC-Ⅱ)是蛋白质呈递途径的核心,其功能受雌激素调节,可通过参与由T和B淋巴细胞介导的适应性免疫反应,促进T细胞衍生各种炎症因子,最终促进破骨细胞介导的骨骼的骨形成和骨吸收。笔者就雌激素、MHC-Ⅱ、淋巴细胞及其在破骨细胞分化过程及功能活性中的潜在机制进行综述,进而更好地理解MHC-Ⅱ在绝经后骨质疏松症中的可能作用。

肿瘤坏死因子α对骨组织细胞的调节

背景:肿瘤坏死因子α是一种作用广泛的炎性细胞因子,在机体的免疫炎症反应中起重要作用。目前的研究认为,肿瘤坏死因子α对多种骨组织细胞具有显著的生物学效应。目的:总结肿瘤坏死因子α在成骨及破骨细胞中的表达及作用途径,以进一步阐明肿瘤坏死因子α对骨组织细胞的调控作用。方法:检索截至2023年3月的PubMed及中国知网数据库中的相关文献,中文检索词包括“肿瘤坏死因子α,成骨细胞,破骨细胞,骨细胞,骨祖细胞”;英文检索词包括“TNF-α,osteoblast,osteoclast,osteocyte,osteoprogenitor cell”,并根据研究需要确立相应的标准,对最终所得文献进行筛选,最终纳入77篇文献进行综述。结果与结论:①肿瘤坏死因子α参与调控了骨祖细胞的募集、增殖与分化,但在特定环境下导致骨祖细胞剥离及死亡。同时通过分泌酶类直接或间接参与骨质吸收。②肿瘤坏死因子α能够通过激活破骨系细胞中相关信号通路,提高环境中炎性因子水平,或在特定环境下直接诱导破骨细胞生成。③肿瘤坏死因子α可通过激活核转录因子κB信号通路,抑制RUNX2和Osterix等转录因子的表达从而抑制成骨分化并诱导成骨细胞的凋亡和坏死性凋亡。④肿瘤坏死因子α通过激活骨细胞中核转录因子κB信号通路,诱导RANKL、SOST及DKK1等细胞因子抑制成骨促进破骨,同时增强骨细胞的凋亡,以及凋亡骨组织周围的骨吸收。⑤综合而言,肿瘤坏死因子α在骨组织中的效应以抑制成骨、促进破骨为主,肿瘤坏死因子α在骨组织细胞中实现生物效应通常依赖于肿瘤坏死因子受体及核转录因子κB信号通路的激活。⑥未来的研究中肿瘤坏死因子α与骨组织周围其他组织细胞类型的交互以及在骨免疫调控中的作用仍值得关注。

新补骨脂异黄酮对破骨细胞形成及破骨基因表达的作用

目的:探讨新补骨脂异黄酮对破骨细胞形成及破骨相关基因表达的影响。方法:采用CCK-8法检测不同浓度新补骨脂异黄酮对RAW 264.7细胞增殖的影响,并筛选出最佳干预浓度;通过TRAP活性染色和细胞骨架F-actin染色评估新补骨脂异黄酮对破骨细胞形成的影响;通过实时定量PCR技术检测破骨细胞分化相关基因基质金属蛋白酶9、组织蛋白酶K、和原癌基因c-Fos的mRNA表达。结果:在12.5μM及以下的浓度,新补骨脂异黄酮对RAW 264.7细胞无显著毒性;TRAP染色活性染色结果表明,新补骨脂异黄酮可以抑制破骨细胞分化;细胞骨架F-actin染色结果表明,新补骨脂异黄酮减小破骨细胞肌动蛋白纤维环的产生,抑制了破骨分化;新补骨脂异黄酮抑制原癌基因c-Fos(P<0.05),显著抑制基质金属蛋白酶9和组织蛋白酶K(P<0.01)等破骨细胞分化的mRNA的表达。结论:新补骨脂异黄酮能够在体外抑制破骨相关基因的表达,进而抑制破骨细胞的生成。

Notch信号通路与骨质疏松症及中医药防治

背景:近年研究表明,Notch信号通路对骨质疏松症有不同程度的影响,深入该方向的研究对骨质疏松的防治具有重要意义。目前,中医药以其多角度、多层次和不良反应小的明显优势在缓解骨质疏松方面发挥显著作用,已成为当今社会研究的重点。目的:分析、整理国内外文献,进一步了解Notch信号通路与骨质疏松症的联系,阐明中医药调控Notch信号通路防治骨质疏松症的作用机制。方法:以“Notch、骨质疏松症、成骨细胞、破骨细胞、骨髓间充质干细胞、信号通路、中药、丸、实验”等为中文检索词,检索中国知网、万方、维普数据库;以“Notch、osteoporosis、Osteoblasts、Osteoclasts、Mesenchymal stem cells、Signal pathway、traditional Chinese medicine、pill、experiment”等为英文检索词,检索PubMed、Nature、Embase数据库,选择各数据库建库至2022年10月的相关文献。结果与结论:Notch信号通路通过参与调控间充质干细胞、成骨细胞和破骨细胞的分化、增殖,从而在不同程度上影响骨质疏松症的发生和进展;Notch信号通路通过直接或间接调控Notch1、Jagged1、Hes、Hey、巨噬细胞集落刺激因子、核因子κB受体活化因子配体等关键细胞因子调节间充质干细胞、成骨细胞和破骨细胞的增殖、分化,进而对骨形成起到促进或抑制的作用,最终对骨质疏松症起到一定的防治效果。中药活性成分大多从补肾类中药提取,如淫羊藿、杜仲、补骨脂、刺五加、女贞子等,且中药复方及制剂都具有补肾强骨的功效,这为后续研究Notch信号通路向防治骨质疏松症提供更多的中药选择和方向。目前中药的研究多为活性成分和单味药提取物,中药复方及制剂的临床实验研究相对较少;关于针灸、推拿、中西医结合等疗法调控Notch信号通路防治骨质疏松症的研究较少,未来还需继续探索中医技术类疗法及中西医结合等疗法对Notch信号通路的调控和对骨质疏松治疗的作用机制。