Role of osteoprotegerin/receptor activator of nuclear factor kappa B/receptor activator of nuclear factor kappa B ligand axis in nonalcoholic fatty liver disease

Concomitantly with the increase in the prevalences of overweight/obesity, nonalcoholic fatty liver disease(NAFLD) has worldwide become the main cause of chronic liver disease in both adults and children. Patients with fatty liver display features of metabolic syndrome(Met S), like insulin resistance(IR), glucose intolerance, hypertension and dyslipidemia. Recently, epidemiological studies have linked obesity, Met S, and NAFLD to decreased bone mineral density and osteoporosis, highlighting an intricate interplay among bone, adipose tissue, and liver. Osteoprotegerin(OPG), an important symbol of the receptor activator of nuclear factor-B ligand/receptor activator of nuclear factor kappa B/OPG system activation, typically considered for its role in bone metabolism, may also play critical roles in the initiation and perpetuation of obesityrelated comorbidities. Clinical data have indicated that OPG concentrations are associated with hypertension, left ventricular hypertrophy, vascular calcification, endothelial dysfunction, and severity of liver damage in chronic hepatitis C. Nonetheless, the relationship between circulating OPG and IR as a key feature of Met S as well as between OPG and NAFLD remains uncertain. Thus, the aims of the present review are to provide the existent knowledge on these associations and to discuss briefly the underlying mechanisms linking OPG and NAFLD.

Dietary saturated fatty acid and polyunsaturated fatty acid oppositely affect hepatic NOD-like receptor protein 3 inflammasome through regulating nuclear factor-kappa B activation

AIM: To investigate the effect of different dietary fatty acids on hepatic inflammasome activation.METHODS: Wild-type C57BL/6 mice were fed either a high-fat diet or polyunsaturated fatty acid (PUFA)-enriched diet. Primary hepatocytes were treated with either saturated fatty acids (SFAs) or PUFAs as well as combined with lipopolysaccharide (LPS). The expression of NOD-like receptor protein 3 (NLRP3) inflammasome, peroxisome proliferator-activated receptor-γ and nuclear factor-kappa B (NF-κB) was determined by real-time PCR and Western blot. The activity of Caspase-1 and interleukine-1β production were measured.RESULTS: High-fat diet-induced hepatic steatosis was sufficient to induce and activate hepatic NLRP3 inflammasome. SFA palmitic acid (PA) directly activated NLRP3 inflammasome and increased sensitization to LPS-induced inflammasome activation in hepatocytes. In contrast, PUFA docosahexaenoic acid (DHA) had the potential to inhibit NLRP3 inflammasome expression in hepatocytes and partly abolished LPS-induced NLRP3 inflammasome activation. Furthermore, a high-fat diet increased but PUFA-enriched diet decreased sensitization to LPS-induced hepatic NLRP3 inflammasome activation in vivo. Moreover, PA increased but DHA decreased phosphorylated NF-κB p65 protein expression in hepatocytes.CONCLUSION: Hepatic NLRP3 inflammasome activation played an important role in the development of non-alcoholic fatty liver disease. Dietary SFAs and PUFAs oppositely regulated the activity of NLRP3 inflammasome through direct activation or inhibition of NF-κB.

Receptor activator of nuclear factorκB ligand/osteoprotegerin axis and vascular calcifications in patients with chronic kidney disease

Vascular calcifications are commonly observed in patients with chronic kidney disease （CKD） and contri-bute to the excessive cardiovascular morbidity and mortality rates observed in these patients populations. Although the pathogenetic mechanisms are not yet fully elucidated, recent evidence suggests a link between bone metabolism and the development and progression of vascular calcifications. Moreover, accumulating data indicate that receptor activator of nuclear factor κB ligand/osteoprotegerin axis which plays essential roles in the regulation of bone metabolism is also involved in extra-osseous bone formation. Further studies are required to establish the prognostic significance of the above biomarkers as predictors of the presence and severity of vascular calcifications in CKD patients and of cardiovascular morbidity and mortality. Moreover, randomized clinical trials are needed to clarify whether inhibition of osteoclast activity will protect from vascular calcifcations.

Effect of Triptolide on Expression of Receptor Activator of Nuclear Factor-κB Ligand in Rat Adjuvant Induced Arthritis

The effect of triptolide （TP） on the expression of receptor activator of nuclear factor-κB ligand （RANKL） and osteoprotegerin （OPG） was explored in rat adjuvant induced arthritis （AA）. AA was induced in Wistar rats. Arthritis rats were treated with TP and methotrexate （MTX） at the onset （day 9） of arthritis. On the peak of arthritis （day 24）, the expression of RANKL and OPG protein in the joints and RANKL mRNA in peripheral blood mononuclear cells （PBMC） was detected. TNF-α and IL-1β levels in peripheral blood were determined. Bone erosion scores were also evaluated. The results showed that bone erosion scores in TP and MTX groups were lower than in AA group （.P〈0.01） ; The expression levels of RANKL in the synovium （P〈0.01） and bone （P〈0.05）, and OPG level in synovium （P〈0.05） were lower in TP group than in AA group （P〈0.05）. In TP group, the expression levels of RANKL mRNA and TNF-α, IL-1β in PBMC were lower than in AA group （all P〈0.01）. It was concluded that TP could inhibit rat adjuvant arthritis bone erosion by suppressing the expression of RANKL.

Influence of baicalin on the expression of receptor activator of nuclear factor-κB ligand and osteoprotegerin in human periodontal ligament cells

Objective To study the effect of baicalin on the expression of receptor activator of nuclear factor-κB ligand(RANKL)and osteoprotegerin(OPG)in cultured human periodontal ligament(HPDL)cells.Methods Small interfering RNA(siRNA)eukaryotic expression vector targeted transforming growth factor βⅡ receptor(TGF-β RⅡ)was constructed and transfected into T cells.HPDL cells with T cells transfected with siRNA or not were placed in the culture medium that had been added with lipopolysaccharide(LPS)and baicalin.The obtained solution was divided into six groups according to the components(group Ⅰ:HPDL cells+LPS+T cells transfected with siRNA1+baicalin;group Ⅱ:HPDL cells+LPS+T cells transfected with siRNA1;group Ⅲ:HPDL cells+LPS+T cells+baicalin;group Ⅳ:HPDL cells+LPS+T cells;group Ⅴ:HPDL cells+baicalin;group Ⅵ:HPDL cells)and was cultured for 48 hours.RT-PCR was used to observe the effect of baicalin on the expression of OPG-RANKL in HPDL cells.Results The ratio of RANKL/OPG in group Ⅰ was lower than that in group Ⅱ(P<0.01)and higher than that in group Ⅲ(P<0.01);The ratio of RANKL/OPG in group Ⅲ was lower than that in group Ⅳ(P<0.01);the ratio of RANKL/OPG in group Ⅳ was higher than that in group Ⅵ(P<0.01);the ratio of RANKL/OPG in group Ⅴ was lower than that in group Ⅵ(P<0.05).Conclusion ① Baicalin could decrease the ratio of RANKL/OPG in HPDL cells.② The TGF-β signaling transduction plays an important role in the effect of baicalin on the RANKL/OPG ratio in HPDL cells.③ Baicalin acts not only through TGF-β to regulate RANKL/OPG in HPDL cells,but also through other pathways.

基于核因子κB受体活化因子配体信号通路激活破骨细胞治疗骨结核的研究进展

骨结核是一种严重危害人体健康的骨科感染性疾病,其病灶组织破坏的最大特点是骨质的吸收及破坏,其中破骨细胞是骨吸收的主要细胞。破骨细胞是由造血干细胞分化而来的多核细胞,通常是由核因子κB受体活化因子配体(receptor activator of nuclear factor-κB ligand,RANKL)与核因子κB受体活化因子(receptor activator for nuclear factor-κB,RANK)调控产生。结核分枝杆菌可以通过RANKL信号通路激活破骨细胞生成转录因子,以增强破骨细胞对骨质的吸收。笔者通过综述RANKL信号通路的结构及破骨细胞的研究进展,以及它们在骨结核临床治疗中可能发挥的潜在作用,为该领域的研究提供新的思路。

Jianpi Gushen Huayu decoction ameliorated diabetic nephropathy through modulating metabolites in kidney,and inhibiting TLR4/NF-κB/NLRP3 and JNK/P38 pathways

BACKGROUND Jianpi Gushen Huayu Decoction(JPGS)has been used to clinically treat diabetic nephropathy(DN)for many years.However,the protective mechanism of JPGS in treating DN remains unclear.AIM To evaluate the therapeutic effects and the possible mechanism of JPGS on DN.METHODS We first evaluated the therapeutic potential of JPGS on a DN mouse model.We then investigated the effect of JPGS on the renal metabolite levels of DN mice using non-targeted metabolomics.Furthermore,we examined the effects of JPGS on c-Jun N-terminal kinase(JNK)/P38-mediated apoptosis and the inflammatory responses mediated by toll-like receptor 4(TLR4)/nuclear factor-kappa B(NF-κB)/NOD-like receptor family pyrin domain containing 3(NLRP3).RESULTS The ameliorative effects of JPGS on DN mice included the alleviation of renal injury and the control of inflammation and oxidative stress.Untargeted metabolomic analysis revealed that JPGS altered the metabolites of the kidneys in DN mice.A total of 51 differential metabolites were screened.Pathway analysis results indicated that nine pathways significantly changed between the control and model groups,while six pathways significantly altered between the model and JPGS groups.Pathways related to cysteine and methionine metabolism;alanine,tryptophan metabolism;aspartate and glutamate metabolism;and riboflavin metabolism were identified as the key pathways through which JPGS affects DN.Further experimental validation showed that JPGS treatment reduced the expression of TLR4/NF-κB/NLRP3 pathways and JNK/P38 pathway-mediated apoptosis related factors.CONCLUSION JPGS could markedly treat mice with streptozotocin(STZ)-induced DN,which is possibly related to the regulation of several metabolic pathways found in kidneys.Furthermore,JPGS could improve kidney inflammatory responses and ameliorate kidney injuries in DN mice via the TLR4/NF-κB/NLRP3 pathway and inhibit JNK/P38 pathwaymediated apoptosis in DN mice.

核因子κB受体活化因子信号转导机制与破骨细胞的活化

背景:破骨细胞是目前已知的唯一一种骨吸收细胞,其生命活动对骨骼的正常发育和骨骼损伤修复至关重要。在绝大多数骨病中,破骨细胞均显示出异常增殖分化和骨吸收活性增加,而核因子κB受体活化因子信号是调控破骨细胞生命过程的关键信号通路。目的:总结对破骨细胞核因子κB受体活化因子信号下游靶点及DNA转录因子的最新研究进展,为相关疾病的研究和治疗提供依据。方法:文献检索数据库包括中国知网、万方、维普数据库、PubMed、Embase及Web of Science数据库,中文检索词为“破骨细胞,破骨前体细胞,骨质疏松症,骨代谢,发病机制,表观遗传学,信号通路,信号传导,转录因子,组织工程”,英文检索词为“osteoclasts,osteoclast precursor cells,osteoporosis,bone metabolism,pathogenesis,epigenetics,signaling pathway,signal transduction,transcription factors,tissue engineering”,时间设置为2017-2021年,根据纳入和排除标准共筛选52篇文献。结果与结论:核因子κB受体活化因子的特殊结构决定了其信号传导需要与肿瘤坏死因子受体激活因子6结合来募集多种蛋白、活性酶以及细胞因子,形成具有内在酶活性的核因子κB受体活化因子复合物;该复合物通过激活核因子κB、丝裂原活化蛋白激酶等信号通路的传导,最终调控破骨细胞分化、增殖、骨吸收等生命过程。

Puerarin partly counteracts the inflammatory response after cerebral ischemia/reperfusion via activating the cholinergic anti-inflammatory pathway

Puerarin, a major isoflavonoid derived from the Chinese medical herb radix puerariae （Gegen）, has been reported to inhibit neuronal apoptosis and play an anti-inflammatory role in focal cerebral ischemia model rats. Recent findings regarding stroke pathophysiology have recognized that anti-inflammation is an important target for the treatment of ischemic stroke. The cholinergic anti-inflammatory pathway is a highly robust neural-immune mechanism for inflammation control. This study was to investigate whether activating the cholinergic anti-inflammatory pathway can be involved in the mechanism of inhibiting the inflammatory response during puerarin-induced cerebral ischemia/reperfusion in rats. Results showed that puerarin pretreatment （intravenous injection） re- duced the ischemic infarct volume, improved neurological deficit after cerebral ischemia/reperfusion and decreased the levels of interleukin-1β, interleukin-6 and tumor necrosis factor-a in brain tissue. Pretreatment with puerarin （intravenous injection） attenuated the inflammatory response in rats, which was accompanied by janus-activated kinase 2 （JAK2） and signal transducers and activators of transcription 3 （STAT3） activation and nuclear factor kappa B （NF-KB） inhibition. These observa- tions were inhibited by the alpha7 nicotinic acetylcholine receptor （a7nAchR） antagonist a-bungarotoxin （a-BGT）. In addition, puerarin pretreatment increased the expression of a7nAchR mRNA in ischemic cerebral tissue. These data demonstrate that puerarin pretreatment strongly protects the brain against cerebral ischemia/reperfusion injury and inhibits the inflammatory re- sponse. Our results also indicated that the anti-inflammatory effect of puerarin may partly be medi- ated through the activation of the cholinergic anti-inflammatory pathway.

TLR4 upregulates CBS expression through NF-κB activation in a rat model of irritable bowel syndrome with chronic visceral hypersensitivity

AIM:To investigate the roles of toll-like receptor 4(TLR4) and nuclear factor(NF)-κB on cystathionine βsynthetase(CBS) expression and visceral hypersensitivity in rats.METHODS:This study used 1-7-wk-old male SpragueDawley rats.Western blot analysis was employed to measure the expression of TLR4,NF-kB and the endogenous hydrogen sulfide-producing enzyme CBS in colon dorsal root ganglia(DRG) from control and "irritable bowel syndrome" rats induced by neonatal colonic inflammation(NCI).Colon-specific DRG neurons were labeled with Dil and acutely dissociated to measure excitability with patch-clamp techniques.Immunofluorescence was employed to determine the co-expression of TLR4,NF-kB and CBS in Dil-labeled DRG neurons.RESULTS:NCI significantly upregulated the expression of TLR4 in colon-related DRGs(0.34 ± 0.12 vs 0.72 ±0.02 for the control and NCI groups,respectively,P <0.05).Intrathecal administration of the TLR4-selective inhibitor CLI-095 significantly enhanced the colorectal distention threshold of NCI rats.CLI-095 treatment also markedly reversed the hyperexcitability of colonspecific DRG neurons and reduced the expression of CBS(1.7 ± 0.1 vs 1.1 ± 0.04,p < 0.05) and of the NF-kB subunit p65(0.8 ± 0.1 vs 0.5 ± 0.1,P< 0.05).Furthermore,the NF-KB-selective inhibitor pyrrolidine dithiocarbamate(PDTC) significantly reduced the upregulation of CBS(1.0 ± 0.1 vs 0.6 ± 0.1,P< 0.05)and attenuated visceral hypersensitivity in the NCI rats.In vitro,incubation of cultured DRG neurons with the TLR4 agonist lipopolysaccharide significantly enhanced the expression of p65(control vs 8 h:0.9 ± 0.1 vs1.3 ± 0.1;control vs 12 h:0.9 ± 0.1 vs 1.3 ± 0.1,P< 0.05;control vs 24 h:0.9 ± 0.1 vs 1.6 ± 0.1,P <0.01) and CBS(control vs 12 h:1.0 ± 0.1 vs 2.2 ±0.4;control vs 24 h:1.0 ± 0.1 vs 2.6 ± 0.1,P< 0.05),whereas the inhibition of p65 via pre-incubation with PDTC significantly reversed the upregulation of CBS expression(1.2 ± 0.1 vs 0.6 ± 0.0,P< 0.01).CONCLUSION:Our results suggest that the activation of TLR4 by NCI upregulates CBS expression,which is mediated by the NF-kB signaling pathway,thus contributing to visceral hypersensitivity.

Medicinal plant activity on Helicobacter pylori related diseases

More than 50% of the world population is infected with Helicobacter pylori (H. pylori). The bacterium highly links to peptic ulcer diseases and duodenal ulcer, which was classified as a group&#x02005;I&#x02005;carcinogen in 1994 by the WHO. The pathogenesis of H. pylori is contributed by its virulence factors including urease, flagella, vacuolating cytotoxin A (VacA), cytotoxin-associated gene antigen (Cag A), and others. Of those virulence factors, VacA and CagA play the key roles. Infection with H. pylori vacA-positive strains can lead to vacuolation and apoptosis, whereas infection with cagA-positive strains might result in severe gastric inflammation and gastric cancer. Numerous medicinal plants have been reported for their anti-H. pylori activity, and the relevant active compounds including polyphenols, flavonoids, quinones, coumarins, terpenoids, and alkaloids have been studied. The anti-H. pylori action mechanisms, including inhibition of enzymatic (urease, DNA gyrase, dihydrofolate reductase, N-acetyltransferase, and myeloperoxidase) and adhesive activities, high redox potential, and hydrophilic/hydrophobic natures of compounds, have also been discussed in detail. H. pylori-induced gastric inflammation may progress to superficial gastritis, atrophic gastritis, and finally gastric cancer. Many natural products have anti-H. pylori-induced inflammation activity and the relevant mechanisms include suppression of nuclear factor-&#x003ba;B and mitogen-activated protein kinase pathway activation and inhibition of oxidative stress. Anti-H. pylori induced gastric inflammatory effects of plant products, including quercetin, apigenin, carotenoids-rich algae, tea product, garlic extract, apple peel polyphenol, and finger-root extract, have been documented. In conclusion, many medicinal plant products possess anti-H. pylori activity as well as an anti-H. pylori-induced gastric inflammatory effect. Those plant products have showed great potential as pharmaceutical candidates for H. pylori eradication and H. pylori induced related gastric disease prevention.

Magnolol protects against acute gastrointestinal injury in sepsis by down-regulating regulated on activation,normal T-cell expressed and secreted

BACKGROUND Sepsis is a major medical challenge.Magnolol is an active constituent of Houpu that improves tissue function and exerts strong anti-endotoxin and anti-inflammatory effects,but the mechanism by which it reduces intestinal inflammation in sepsis is yet unclear.AIM To assess the protective effect of magnolol on intestinal mucosal epithelial cells in sepsis and elucidate the underlying mechanisms.METHODS Enzyme-linked immunosorbent assay was used to measure tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),IL-6,and regulated on activation,normal T-cell expressed and secreted(RANTES)levels in serum and ileal tissue in animal studies.The histopathological changes of the ileal mucosa in different groups were observed under a microscope.Cell Counting Kit-8 and cell permeability assays were used to determine the concentration of drug-containing serum that did not affect the activity of Caco2 cells but inhibited lipopolysaccharide(LPS)-induced decrease in permeability.Immunofluorescence and Western blot assays were used to detect the levels of RANTES,inhibitor of nuclear factor kappa-B kinaseβ(IKKβ),phosphorylated IKKβ(p-IKKβ),inhibitor of nuclear factor kappa-B kinaseα(IκBα),p65,and p-p65 proteins in different groups in vitro.RESULTS In rats treated with LPS by intravenous tail injection in the presence or absence of magnolol,magnolol inhibited the expression of proinflammatory cytokines,IL-1β,IL-6,and TNF-αin a dose-dependent manner.In addition,magnolol suppressed the production of RANTES in LPS-stimulated sepsis rats.Moreover,in vitro studies suggested that magnolol inhibited the increase of p65 nucleation,thereby markedly downregulating the production of the phosphorylated form of IKKβin LPS-treated Caco2 cells.Specifically,magnolol inhibited the translocation of the transcription factor nuclear factor-kappa B(NF-κB)from the cytosol into the nucleus and down-regulated the expression level of the chemokine RANTES in LPS-stimulated Caco2 cells.CONCLUSION Magnolol down-regulates RANTES levels by inhibiting the LPS/NF-κB signaling pathways,thereby suppressing IL-1β,IL-6,and TNF-αexpression to alleviate the mucosal barrier dysfunction in sepsis.

核因子κB受体活化因子配体抑制剂地舒单抗在肺癌骨转移中的应用

目前,随着基因靶向治疗和免疫治疗在肺癌领域中取得巨大突破,晚期肺癌患者总生存期(OS)显著延长,但发生远处骨转移及骨相关事件(SRE),如骨痛、病理性骨折、脊髓压迫、高钙血症等风险也随之增大,严重影响了患者的生活质量。因此,在全身治疗基础上应积极预防和治疗骨转移及SRE治疗。临床研究表明,核因子κB受体活化因子(RANK)配体(RANKL)/RANK/骨保护素信号通路在肿瘤骨转移中发挥着重要作用,阻断该通路能有效预防和治疗SRE。RANKL抑制剂地舒单抗(商品名:安加维)是一种人免疫球蛋白G2单克隆抗体,可特异性结合RANKL而阻断破骨细胞参与的RANKL/RANK/骨保护素信号通路激活,最终发挥预防骨转移及SRE的作用。与双磷酸盐类药物比较,地舒单抗疗效显著,能明显延长患者OS和SRE的发生时间。同时,地舒单抗还具有抗肿瘤作用。该文就地舒单抗的作用机制、临床研究及安全性等方面的最新研究进行了阐述,以期为临床医生提供参考。

Different effects of antisense IRAK-2 oligonucleotide on IL-1 and TNF-stimulated NF-kappa B activation

Objective: To investigate the role of interleukin-1 (IL-1) receptor associated kinase-2 (IRAK-2) in IL1 and TNF-stimulated nuclear factor-kappa B (NF-kappa B ) activation. Metbods: The 293 cell was trans fectedwith antisense IRAK-2 oligonucleotide (IRAK-2 ODN) followed by stimulating the cell with IL-1 or tumor necrosis factor (TNF), and then the levels of NF-kappa B activation was analyzed by sandwich enzyme-linked immunosorbent assay (ELISA ). Result: Pre-transfecting with antisense IRAK-2 ODN could remarkably decreasethe levels of NF-kappa B activation stimulated by IL-1 in time- and concentration-dependent manner, it can not attenuate the one stimulated by TNF. Conclusion: The responses of IL-1 and TNF-stimulated NF-kappa B activation to antisense IRAK-2 oligonucleotids were different. IRAK-2 plays a key role in the IL-1 signaling events leading to NF kappa B activation.

基于骨免疫学论中医药抑制类风湿关节炎骨破坏的研究进展

类风湿关节炎(RA)是一种以滑膜炎、软骨与骨破坏为主要病理表现的自身免疫性疾病,致残率较高。RA免疫及炎症反应与骨细胞代谢互为影响,其核心环节为破坏机体核因子κB受体活化因子配体/核因子κB受体活化因子/骨保护素(RANKL/RANK/OPG)信号通路的平衡,导致成骨细胞减少,以及破骨细胞凋亡减退及异常活化。西药目前以抑制炎症反应及相关细胞因子分泌,减缓疾病进展,但长期使用其不良反应难以忽视。中医药在防治骨破坏中研究逐步深入,但在基础及临床研究方面仍存在一定局限性。

龈沟液RANKL、音猬因子水平对牙缺失Nobel种植体早期稳定性评估价值

目的探讨龈沟液核因子-κB受体活化因子配体(RANKL)、音猬因子水平对牙缺失Nobel种植体早期稳定性评估价值。方法选取2020年6月至2021年12月邯郸市第一医院牙缺失患者128例作为观察组,均为Nobel种植体修复,选取同期体检健康者64例作为对照组。对比两组及观察组术后即刻、术后3个月龈沟液RANKL、音猬因子水平、种植体稳定系数(ISQ)值,多重线性回归模型分析Nobel种植体早期稳定性影响因素,并分析龈沟液RANKL、音猬因子水平对早期稳定性评估价值。结果观察组术后3个月龈沟液RANKL、音猬因子水平低于术后即刻,差异有统计学意义(P<0.05);观察组术后3个月ISQ值高于术后即刻,差异有统计学意义(P<0.05)。术后即刻龈沟液RANKL、音猬因子水平与术后3个月ISQ值呈负相关(P<0.05)。术后即刻及术后3个月龈沟液RANKL、音猬因子水平对应的线性系数差异有统计学意义(P<0.05);建立多重线性回归模型:术后3个月ISQ值=100.968-4.607×术后咬(牙合)痛-2.886×常食坚果-0.254×术后即刻龈沟液RANKL-0.280×术后即刻龈沟液音猬因子,回归模型具有统计学意义(P<0.05),自变量可解释术后3个月ISQ值74.59%的变异量。结论牙缺失患者进行Nobel种植后龈沟液RANKL、音猬因子呈低表达,术后通过检测二者水平可有效判断种植体早期稳定性。

PTHrP促进RANKL诱导巨噬细胞分化为破骨细胞参与中耳胆脂瘤骨破坏

目的:骨质进行性吸收破坏是中耳胆脂瘤最重要的临床特征之一,可导致一系列颅内外并发症,而目前中耳胆脂瘤骨破坏的机制尚未明确。本研究旨在探究甲状旁腺激素相关蛋白(parathyroid hormone-related protein,PTHrP)参与中耳胆脂瘤骨破坏的机制。方法:收集后天性中耳胆脂瘤患者的25例胆脂瘤标本和13例外耳道正常皮肤组织标本。采用免疫组织化学染色方法检测PTHrP、核因子κB受体活化因子配体(receptor activator for nuclear factor-kappa B ligand,RANKL)和骨保护素(osteoprotegerin,OPG)在中耳胆脂瘤和外耳道正常皮肤组织中的表达,抗酒石酸酸性磷酸酶(tartrate-resistant acid phosphatase,TRAP)染色法检测中耳胆脂瘤和外耳道正常皮肤组织中是否存在TRAP阳性多核巨噬细胞。选取小鼠单核巨噬细胞RAW264.7细胞进行干预,分为RANKL干预组和PTHrP+RANKL共同干预组,采用TRAP染色法检测2组破骨细胞的生成情况,实时聚合酶链反应(real-time polymerase chain reaction,real-time PCR)检测干预后2组破骨细胞相关基因TRAP、组织蛋白酶K(cathepsin K,CTSK)和活化T细胞核因子1(nuclear factor of activated T cell cytoplasmic 1,NFATc1)的mRNA表达水平,骨吸收陷窝实验检测2组破骨细胞的骨吸收功能。结果:免疫组织化学染色结果显示,PTHrP和RANKL在中耳胆脂瘤组织中的表达均显著增高,OPG表达降低(均P<0.05),且PTHrP的表达与RANKL、RANKL/OPG比值均呈显著正相关,与OPG表达呈显著负相关(分别r=0.385、r=0.417、r=-0.316,均P<0.05)。同时,PTHrP、RANKL的表达水平与中耳胆脂瘤的骨破坏程度均呈显著正相关(分别r=0.413、r=0.505,均P<0.05)。TRAP染色结果显示中耳胆脂瘤上皮周围基质中有大量TRAP阳性细胞,并存在细胞核数量为3个或3个以上的TRAP阳性破骨细胞。RANKL或PTHrP+RANKL联合干预5 d后,与RANKL干预组相比,PTHrP+RANKL联合干预组的破骨细胞数量显著增加(P<0.05),且破骨细胞相关基因TRAP、CTSK和NFATc1的mRNA表达水平均升高(均P<0.05)。骨吸收陷窝扫描电镜结果显示RANKL干预组、PTHrP+RANKL联合干预组的骨片表面均形成骨吸收陷窝;与RANKL干预组相比,PTHrP+RANKL联合干预组的骨片表面骨吸收陷窝数量显著增加(P<0.05),面积也更大。结论:PTHrP可能通过促进RANKL诱导胆脂瘤组织周围基质中的巨噬细胞分化为破骨细胞,参与中耳胆脂瘤骨破坏。

Imbalance of osteoprotegerin/receptor activator of nuclear factor-κB ligand and oxidative stress in patients with obstructive sleep apnea-hypopnea syndrome

Background:Obstructive sleep apnea-hypopnea syndrome (OSAHS) is associated with a higher prevalence of osteoporosis.However,the underlying mechanisms linking OSAHS with bone loss are still unclear.The aim of this study was to investigate the changes of receptor activator of nuclear factor-κB ligand (RANKL,an osteoclastogenesis-promoting factor) and osteoprotegerin (OPG,the decoy receptor for RANKL),oxidative stress and bone metabolism markers in OSAHS,in order to understand the potential mechanisms underlying bone loss in OSAHS patients.Methods:Forty-eight male patients with OSAHS,confirmed by polysomnography (PSG) study,were enrolled.Twenty male subjects who were confirmed as not having OSAHS served as the controls.The subjects’bone mineral density (BMD) was assessed in lumbar spine and femoral neck using dual-energy X-ray absorptiometry (DXA).Blood samples were collected from all subjects for measurement of RANKL,OPG,the bone formation marker bone-specific alkaline phosphatase (BAP),the bone resorption marker tartrate-resistant acid phosphatase 5b (TRAP-5b),and total antioxidant capacity (TAOC).Results:The BMD and the T-score of the femoral neck and the lumbar spine were significantly lower in OSAHS patients as compared to the control group (P< 0.05).The serum level of BAP was significantly decreased in the OSAHS group (15.62 ± 5.20 μg/L) as compared to the control group (18.83 ± 5.50 μg/L,t= -2.235,P< 0.05),while the levels of TRAP-5b did not differ between the two groups (t= -1.447,P> 0.05).The serum level of OPG and the OPG/RANKL ratio were lower in the OSAHS group compared to the control group (bothP< 0.05).TAOC level was also decreased significantly in the OSAHS group (P< 0.05).Correlation analysis showed that the TAOC level was positively correlated with BAP in the OSAHS group (r= 0.248,P= 0.04),but there were no correlations between TAOC and the BMD or the T-scores.The correlations between the level of OPG (or the OPG/RANKL ratio) and BMD or TAOC did not reach significance.Conclusion:In OSAHS patients,lower levels of TAOC were associated with decreased bone formation,suggesting a role of oxidative stress in bone loss,while the role of OPG/RANKL imbalance in bone metabolism in OSAHS needs further evaluation .

Cannabinoid receptor-2 selective antagonist negatively regulates receptor activator of nuclear factor kappa B ligand mediated osteoclastogenesis

Background The cannabinoid receptor-2 （CB2） is important for bone remodeling. In this study, we investigated the effects of CB2 selective antagonist （AM630） on receptor activator of nuclear factor kappa B （RANK） ligand （RANKL）induced osteoclast differentiation and the underlying signaling pathway using a monocyte-macrophage cell line-RAW264.7.Methods RAW264.7 was cultured with RANKL for 6 days and then treated with AM630 for 24 hours. Mature osteoclasts were measured by tartrate-resistant acid phosphatase （TRAP） staining using a commercial kit. Total ribonucleic acid （RNA）was isolated and real-time reverse transcriptase-polymerase chain reaction （RT-PCR） was done to examine the expression of RANK, cathepsin K （CPK） and nuclear factor kappa B （NF-κB）. The extracellular signal-regulated kinase （ERK）,phosphorylation of ERK （P-ERK） and NF-κB production were tested by Western blotting. The effect of AM630 on RAW264.7 viability was determined using the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazoliumbromide （MTT） assay.Results AM630 did not affect the viability of RAW264.7. However, this CB2 selective antagonist markedly inhibited osteoclast formation and the inhibition rate was dose-dependent. The dose of 〉100 nmol/L could reduce TRAP positive cells to the levels that were significantly lower than the control. AM630 suppressed the expression of genes associated with osteoclast differentiation and activation, such as RANK and CPK. An analysis of a signaling pathway showed that AM630 inhibited the RANKL-induced activation of ERK, but not NF-κB.Conclusion AM630 could inhibit the osteoclastogenesis from RAW264.7 induced with RANKL.

Receptor activator of nuclear factor kappa B ligand and osteoprotegerin expression in chronic apical periodontitis：possible association with inflammatory cells

Background Receptor activator of nuclear factor kappa B （NF-κB） ligand （RANKL） and osteoprotegerin （OPG） have been recently shown to play important roles in bone resorption. The aim of this study was to investigate the possible association between the expression of bone resorption regulators （RANKL and OPG） and inflammatory cell infiltration in chronic apical periodontitis.Methods The samples of chronic periapical lesions （n=40） and healthy periapical tissues （n=10） were examined for immunohistochemical analysis of RANKL and OPG. Lesion samples were further analyzed for the inflammatory infiltration condition. The inflammatory cell infiltration was scored in relation to immunohistochemical reactivity for CD3, CD20 and CD68.Results The number of RANKL-positive cells and the ratio of RANKL/OPG in chronic apical periodontitis were significantly higher than those in healthy periapical tissues （P＜0.001）. The number of RANKL-positive cells was higher in lesions with severe inflammatory infiltration than in those with light inflammatory infiltration （P＜0.05）. Significantly increased RANKL expression was found with T lymphocytes （CD3＋）, macrophages （CD68＋） and B lymphocytes （CD20＋）infiltration （P＜0.05）. No association was found between the ratio of RANKL/OPG and inflammatory cell infiltration.Conclusions RANKL expression was increased with T, B lymphocytes and macrophages infiltration, respectively in chronic periapical lesions. RANKL appears to be closely related to periapical inflammatory infiltrates. The relative ratio of RANKL/OPG may be a key determinant of RANKL-mediated bone resorption.