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.

Increased Expression of Receptor Activator of Nuclear Factor-κB Ligand in Osteoblasts from Adolescent Idiopathic Scoliosis Patients with Low Bone Mineral Density

Persistent generalized low bone mineral density (BMD) has been reported in patients with adolescent idiopathic scoliosis (AIS).However,the exact mechanisms and causes of the low BMD in AIS patients are largely unknown.The purpose of this study was to examine the relationship between the receptor activator of NF-κB ligand (RANKL)/osteoprotegerin (OPG) levels in osteoblasts (OBs) from AIS patients with low BMD and with comparison made between the patients and controls.Twenty AIS patients and eight age-matched controls were included in the present study.The BMD of lumbar spine and proximal femur was measured in all subjects.OBs from the cancellous bone of each subject was harvested and primarily cultured.The mRNA and protein expression of RANKL and OPG in OBs was detected by RT-PCR and Western blotting.The results showed BMD was lower in AIS patients than in controls.A significantly higher mRNA and protein expression of RANKL was observed in OBs from AIS patients,while no significant difference was found in the expression of OPG between AIS patients and controls.As a result,RANKL/OPG ratio in patients with AIS was remarkably higher than controls.Our study preliminarily demonstrated expression of RANKL was higher in OBs from AIS patients with low BMD as compared with controls,suggesting the unbalanced RANKL/OPG ratio caused by an over-expression of RANKL in OBs may be responsible for the low BMD in AIS patients.

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.

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 contribute 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 calcifications.

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.

骨保护素/核因子κB受体活化因子/核因子κB受体活化因子配体调节骨代谢及其靶向治疗在口腔领域的应用

背景:骨保护素/核因子κB受体活化因子/核因子κB受体活化因子配体是偶联破骨细胞、成骨细胞分化和活化的重要细胞因子,是调节骨代谢的关键因子,影响着免疫系统、骨的再生和重塑,与牙槽骨的生理性及病理性改建密切相关。目的:分析总结骨保护素/核因子κB受体活化因子/核因子κB受体活化因子配体信号通路对牙槽骨改建的影响及其靶向治疗在口腔领域应用研究中的进展。方法:检索中国知网及PubMed数据库收录的相关文献。中文检索词为“骨保护素,抗RANKL抗体,核因子κB受体活化因子配体,牙周炎,正畸牙移动,种植,牙齿萌出,根尖周病变,牙槽骨吸收”,英文检索词为“OPG,anti-RANKL antibody,RANKL,periodontitis,orthodontic tooth movement,implant,tooth eruption,periapical lesion,alveolar bone resorption”,最终纳入63篇文献进行归纳总结。结果与结论:①抗核因子κB受体活化因子配体通过靶向抑制破骨细胞形成和牙槽骨吸收来治疗口腔疾病;②局部和全身抗核因子κB受体活化因子配体治疗可以抑制牙周炎、种植体周围炎、根尖周病变的进展,且其在预防正畸后复发、增强正畸支抗和种植体骨结合方面也发挥重要作用;③核因子κB受体活化因子配体通过靶向促进破骨细胞分化来治疗口腔疾病;④核因子κB受体活化因子配体治疗可以加速正畸牙移动、缩短治疗周期、减少正畸并发症的发生;⑤虽然抗核因子κB受体活化因子配体治疗存在局限性,但是可以通过合理应用如应用前排除危险因素,应用期间定期口腔维护、避免创伤性牙槽手术等措施来规避。

Potential PET Ligands for Imaging of Cerebral VPAC and PAC Receptors: Are Non-Peptide Small Molecules Superior to Peptide Compounds?

Pituitary adenylate cyclase activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) have been known for decades to mediate neuroendocrine and vasodilative actions via G-protein-coupled receptors of Class B. These are targets of imaging probes for positron emission tomography (PET) or single photon emission tomography (SPECT) in tumor diagnostics and tumor grading. However, they play only a subordinate role in the development of tracers for brain imaging. Difficulties in development of non-peptide ligands typical for cerebral receptors of PACAP and VIP are shared by all members of Class B receptor family. Essential landmarks have been confirmed for understanding of structural details of Class B receptor molecular signalling during the last five years. High relevance in the explanation of problems in ligand development for these receptors is admitted to the large N-terminal?ectodomain markedly different from Class A receptor binding sites and poorly suitable as orthosteric binding sites for the most small-molecule compounds. The present study is focused on the recently available receptor ligands for PAC1, VPAC1 and VPAC2 receptors as well as potential small-molecule lead structures suitable for use in PET or SPECT. Recently, biaryl, cyanothiophene and pentanamide structures with affinities in nM-range have been proposed as non-peptide ligands at VPAC1 and VPAC2 receptors. However, most of these ligands have been classified as non-competitive related to the orthosteric binding site of endogenous peptide ligands of VPAC receptors. For PAC1 receptors have been identified hydrazide compounds for which an inhibitory and potentially competitive mechanism of receptor binding has been postulated based on molecular docking studies.

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。

基于TLR4/NF-κB信号通路及血清CXCL16、ACA评价依达拉奉右莰醇对ACI神经功能的保护作用

目的基于Toll样受体(TLR)4/核因子κB(NF-κB)信号通路及血清CXC型趋化因子配体16(CXCL16)、抗心磷脂抗体(ACA)评价依达拉奉右莰醇治疗急性脑梗死(ACI)的疗效及神经功能保护作用。方法将102例ACI患者根据是否使用依达拉奉右莰醇分为两组:观察组(n=54)均在常规治疗基础上接受依达拉奉右莰醇治疗,对照组(n=48)未用依达拉奉治疗。对比两组治疗前及治疗7d、14d、30d后神经功能缺损量表(NIHSS),治疗前及治疗14d检测血清TLR4、NF-κB、白介素1β(IL-1β)、白介素6(IL-6)、肿瘤坏死因子α(TNF-α)、CXCL16、ACA,随访3个月采用改良Rankin量表(mRS)评价预后。结果治疗后7d、14d、30d,两组NIHSS评分均下降,而观察组明显低于对照组(P<0.05)。治疗14d后,两组血清TLR4、NF-κB、IL-1β、IL-6、TNF-α、CXCL16、ACA水平均下降,且观察组明显低于对照组(P<0.05)。随访3个月,观察组mRS均分低于对照组(P<0.05),但两组预后差异无统计学意义(79.63%vs 68.75%,P>0.05)。结论依达拉奉右莰醇用于ACI的治疗可保护神经功能,其机制可能与调节TLR4/NF-κB信号通路及血清CXCL16、ACA表达有关。

2型糖尿病患者骨保护素和NF-κB受体活化因子配体与左室舒张功能障碍的相关研究

【目的】探讨2型糖尿病(T2DM)患者血清骨保护素(OPG)和可溶性NF-κB受体活化因子配体(sRANKL)水平与可能左室舒张功能障碍(LADD)的相关性。【方法】本研究纳入68例T2DM患者和37例健康对照者,利用ELISA方法测定血清OPG和sRANKL水平,同时利用心脏彩超测定T2DM患者左室舒张功能,E/A<1定义为LADD。进一步将T2DM患者分为E/A≥1和E/A<1两个亚组。采用Spearman相关性分析、logistics回归分析和ROC曲线评估血清OPG和sRANKL与T2DM患者可能LADD的相关性。【结果】与健康对照者相比,T2DM患者血清OPG水平明显升高,差异有统计意义(P<0.01),而sRANKL水平降低,但无统计学意义(P=0.032)。亚组分析则显示E/A<1组的OPG水平较E/A≥1组升高(P<0.01),而sRANKL降低(P<0.01)。Spearman相关性分析显示,血清OPG水平与E/A比值呈负相关,而sRANKL则与E/A比值呈正相关。单因素logistics回归分析显示,血清OPG水平[OR(95%CI)=1.068(1.031,1.106),P<0.001]和sRANKL水平[OR(95%CI)=0.976(0.959,0.992),P=0.003]与T2DM患者可能LVDD显著相关。ROC曲线分析显示,联合OPG与sRANKL诊断糖尿病患者可能LADD的敏感性为78.13%,特异性为88.3%(曲线下面积:0.857;95%CI=(0.768,0.946);P<0.001)。【结论】T2DM患者血清中升高的OPG和降低的sRANKL水平提示其可能与LADD相关。

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 .

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.

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.

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.

低能量激光对人牙周膜细胞白细胞介素-6、肿瘤坏死因子-α、骨保护素、核因子-κB受体活化因子配体表达的影响

目的通过观察高糖环境下低能量激光(LLL)对受静压力刺激的人牙周膜细胞(HPDLC)白细胞介素-6(IL-6)、肿瘤坏死因子(TNF)-α、骨保护素(OPG)、核因子-κB受体活化因子配体(RANKL)表达的影响,以期探究LLL对糖尿病患者牙周组织炎症及正畸治疗过程中骨改建调控的分子生物学机制。方法体外培养HPDLC,模拟正畸加力,结合LLL照射,将所培养细胞随机分为4组:低糖型杜氏改良Eagle培养基(DMEM)+压力刺激(A组),高糖型DMEM+压力刺激(B组),低糖型DMEM+LLL照射+压力刺激(C组),高糖型DMEM+LLL照射+压力刺激(D组),其中C、D组根据给予的激光能量密度值不同又分C1、D1组(能量密度值:3.75 J/cm2)和C2、D2组(能量密度值:5.625 J/cm2)。根据已有分组,对A、B、C、D组细胞进行加力,对C、D组细胞在细胞加力前进行LLL照射。分别观察0、12、24、48、72 h,定时提取各组细胞培养上清液,采用酶联免疫吸附(ELISA)法检测各组不同时段IL-6、TNF-α、OPG、RANKL的蛋白表达。结果1)在持续静压力刺激下,HPDLC分泌的IL-6、TNF-α浓度随时间逐渐上升;12 h后IL-6、TNF-α的浓度在A组与B、C1、C2组组间两两比较的差异均有统计学意义(P<0.05),B组与D1、D2组组间两两比较的差异也均有统计学意义(P<0.01)。2)OPG蛋白浓度在24h之前呈现出上升趋势,24h后随时间出现下降趋势;RANKL蛋白浓度随时间呈上升趋势;OPG/RANKL比值随时间呈下降趋势;持续静压力刺激12h后,A组与B、C1、C2组,B组与D1、D2组组间两两比较的OPG、RANKL及OPG/RANKL的比值的差异均具有统计学意义(P<0.05)。结论1)在高糖环境持续静压力刺激下,HPDLC分泌的IL-6、TNF-α浓度随时间呈现上升趋势;OPG的表达水平降低,RANKL的表达水平增加,OPG/RANKL的比值减小,提示高糖环境会促进骨吸收反应的发生;给予LLL照射干预后发现,IL-6、TNF-α的浓度出现下降,表明其可拮抗高糖环境所致的炎症因子水平的升高,并且能上调人HPDLC中OPG的表达,下调HPDLC中RANKL的表达,从而上调OPG/RANKL的比值,逆转高糖所致的骨代谢失衡。2)在3.75~5.625J/cm2这一能量密度范围内,随着给予的激光能量密度值的增大,其表现出的降低炎症因子及对HPDLC骨代谢的调控作用增强,提示在一定范围内,LLL调节骨改建的能力随剂量增加而增强。

Effect of Wenhua Juanbi Recipe(温化蠲痹方) on Expression of Receptor Activator of Nuclear Factor Kappa B Ligand,Osteoprotegerin,and Tumor Necrosis Factor Receptor Superfamily Member 14 in Rats with Collagen-Induced Arthritis

Objective： To study the effect of Wenhua Juanbi Recipe（温化蠲痹方, WJR） on expression of receptor activator of nuclear factor kappa B ligand（RANKL）, osteoprotegerin（OPG）, and tumor necrosis factor receptor superfamily member 14（TNFRSF14, also known as LIGHT） in rats with collagen-induced arthritis（CIA）. Methods： CIA rats were generated by subcutaneous injection of bovine collagen type-Ⅱ at the tail base. Sixty CIA rats were randomly assigned（10 animals/group） to： model, methotrexate（MTX）-treated（0.78 mg/kg body weight）, and WJR-treated（22.9 g/kg） groups. Healthy normal rats（n=10） were used as the normal control. Treatments or saline were administered once daily by oral gavage. Rats were sacrificed at day 28 post-treatment and knee synovium and peripheral blood serum were collected. Toe swelling degree and expression of RANKL, OPG, and LIGHT were determined by Western blot and immunohistochemistry. Results： Compared with the normal group, toe swelling degree was significantly increased in the model group（P〈0.01）. After treatment, toe swelling degree decreased significantly in the WJR and MTX groups compared with the model group（P〈0.01）. Compared with the normal group, expression of RANKL and LIGHT were significantly increased and OPG significantly decreased in peripheral blood and synovium of the model group（P〈0.01）. Conversely, RANKL and LIGHT expression were significantly reduced and OPG increased in the WJR and MTX groups compared with the model group（P〈0.01）. No statistically significant difference existed between WJR and MTX groups. Conclusion： WJR likely acts by reducing RANKL expression and increasing OPG expression, thus inhibiting RANKL/RANK interaction and reducing LIGHT expression, thereby inhibiting osteoclast formation/activation to block bone erosion.

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.