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.

RANK-ligand and osteoprotegerin as biomarkers in the differentiation between periprosthetic joint infection and aseptic prosthesis loosening

AIM To assess serum levels of RANK-ligand(RANKL) and osteoprotegerin(OPG) as biomarkers for periprosthetic joint infection(PJI) and compare their accuracy with standard tests.METHODS One hundred and twenty patients presenting with a painful total knee or hip arthroplasty with indication for surgical revision were included in this prospective clinical trial. Based on standard diagnostics(joint aspirate, microbiological, and histological samples) and Musculoskeletal Infection Society consensus classification,patients were categorized into PJI, aseptic loosening,and control groups. Implant loosening was assessed radiographically and intraoperatively. Preoperative serum samples were collected and analyzed for RANKL, OPG, calcium, phosphate, alkaline phosphatase(AP), and the bone-specific subform of AP(b AP). Statistical analysis was carried out, testing for significant differences between the three groups and between stable and loose implants. RESULTS All three groups were identical in regards to age, gender, and joint distribution. No statistically significant differences in the serum concentration of RANKL(P = 0.16) and OPG(P = 0.45) were found between aseptic loosening and PJI, with a trend towards lower RANKL concentrations and higher OPG concentrations in the PJI group. The RANKL/OPG ratio was significant for the comparison between PJI and non-PJI(P = 0.005). A ratio > 60 ruled out PJI in all cases(specificity: 100%, 95%CI: 89, 11% to 100.0%) but only 30% of non-PJI patients crossed this threshold. The positive predictive value remained poor at any cut-off. In the differentiation between stable and loose implants, none of the parameters measured(calcium, phosphate, AP, and b AP) showed a significant difference, and only AP and b AP measurements showed a tendency towards higher values in the loosened group(with P = 0.09 for AP and P = 0.19 for b AP). CONCLUSION Lower RANKL and higher OPG concentrations could be detected in PJI, without statistical significance.

Osteoprotegerin,interleukin and hepatocyte growth factor for prediction of diabetes and hypertension in the third trimester of pregnancy

BACKGROUND Gestational diabetes mellitus(GDM)raises the risk of high blood pressure and may cause a series of life-threatening complications in pregnant women.Screening and management of GDM and gestational hypertension(GH)in pregnancy helps to control and reduce these risks and prevent adverse effects on mothers and their fetuses.Currently,the majority criteria used for screening of diabetes mellitus is oral glucose tolerance tests,and blood pressure test is usually used for the screening and diagnosis of hypertension.However,these criteria might not anticipate or detect all GDM or GH cases.Therefore,new specific predictive and diagnostic tools should be evaluated for this population.This study selected three biomarkers of osteoprotegerin(OPG),interleukin(IL)and hepatocyte growth factor(HGF)for GDM and GH predication and diagnosis.AIM To explore the feasibility of changes in placental and serum OPG,IL and HGF as tools for prediction and diagnosis of diabetes and hypertension in pregnant women.METHODS From January 2018 to January 2019,44 pregnant women with GDM and GH were selected as an observation group,and 44 healthy pregnant women were selected as a control group in the same period.Serum OPG,IL and HGF were compared between the two groups.RESULTS The levels of OPG and HGF in the observation group were lower than in the control group,and the level of IL-1βwas higher in the observation group than in the control group(all P<0.05).Furthermore,OPG and HGF were negatively associated with gestational diabetes and gestational hypertension,while IL-1βwas positively associated with GDM complicated with GH(all P<0.05).CONCLUSION The evaluation of serum OPG,HGF and IL-1βlevels in patients with coexistent gestational diabetes complicated with hypertension can predict the degree of disease and play an important role in the follow-up treatment and prognosis prediction.

Integrative Analysis Confirmed the Association between Osteoprotegerin and Osteoporosis

Objective This study aimed to verify the association between osteoprotegerin gene (OPG) and its variants with osteoporosis (OP) by performing integrative analysis.Methods We used the KGG software to perform gene-based association analysis,which integrated all publicly available single-nucleotide polymorphism (SNP)-based P values and obtained an overall P value for the OPG.The significant SNPs were screened for expression quantitative trait loci (eQTLs).Meta-analysis was used to combine the associations between the variants of OPG and bone mineral density (BMD) reported in the literatures.Then we performed dual-luciferase reporter gene systems for the functional verification of the variants of OPG in vitro.Results In the gene-based association analysis,the over all P value of OPG was 6.24×10^-13 for BMD at femoral neck (FN) and 7.37×10^-17 for BMD at lumbar spine (LS),indicating the importance of OPG for OP.The publicly available eQTL database identified 5 eQTLs which exert cis-regulation effects on OPG at FN and LS.Literature searching found that rs2073617 (known as T950C) was the hot spot SNP.There were 13 relevant studies on rs2073617 besides the GEFOS-2 study identified from the PubMed.Significant differences among TT,TC and CC genotypes at FN (P= 0.047) and LS (P= 0.025) were shown by meta-analysis,demonstrating the associations between T950C polymorphism and BMD.Luciferase gene expression was significantly higher at the presence of allele C than allele T in the 293T cells (t=-9.47,P<0.01).Conclusion The integrative analysis further confirmed the importance of OPG in OP and the correlation of T950C polymorphism with BMD of OP.The strategy can be used as a reference for functional interpretation of other disease-related genes.

Alendronate affects osteoprotegerin/receptor of activator of nuclear factor κB-ligand expression in human marrow stroma cells in vitro

Objective To evaluate the effect of alendronate on osteoprotegerin(OPG)and receptor of activator of nuclear factor κB-ligand(RANKL)expression in human marrow stroma cells(hMSCs)in vitro.Methods hMSCs were isolated from human marrow,cultured in vitro,and randomly divided into two groups:alendronate group,hMSCs culture fluid containing 1×10-7mol/L alendronate;control group,no special treatment but culturing hMSCs in DMEM.Two weeks after treatment,the expressions of OPG and RANKL were evaluated by RT-PCR and Western blot.Results hMSCs became uniform spindle-shaped fibroblasts.As cells proliferated,they formed colonies and showed whirlpool arrangement.After one week’s treatment,hMSCs in alendronate group had reduced processes and gradually showed disc shape,which did not happen in control group but kept fibroblast shape and just increased in density.In RT-PCR,the ratio of OPG/RANKL in alendronate group and control group was 8.77±1.16 and 4.58±1.27,respectively.In Western blot,the ratio of OPG/RANKL in alendronate group and control group was 2.58±0.47 and 1.52±0.32,respectively.The ratio of OPG/RANKL was higher in alendronate group than in control group(P<0.01).Conclusion Alendronate enhances OPG expression and inhibits RANKL expression of hMSCs in vitro.

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.

Efficacy of recombinant human osteoprotegerin combined with tinidazole in the treatment of periodontitis mice and its correlation with serum RANKL and MCP-1 levels

Objective: To investigate the effect of recombinant human osteoprotegerin combined with tinidazole on mice with periodontitis and the effect on serum RANKL and MCP-1 levels. Methods: 80 SPF-cleaned mice were randomly divided into 4 groups, 20 each, model group, tinidazole group and recombinant human osteoprotegerin group were modeled by Kimura et al., and tinidazole group received tinidazole. After intragastric administration, the recombinant human osteoprotegerin group was injected with recombinant human osteoprotegerin in the periodontal pocket according to the tinidazole group. The periodontal changes of the four groups of mice were observed and recorded, and the gingival rating was performed. Epithelial tissue morphology was observed by hematoxylin-eosin (HE) staining. Serum levels of IL-4, IL-6, RANKL and MCP-1 were measured by enzyme-linked immunosorbent assay. Results:After the intervention, the model group developed severe inflammatory reactions, including redness, hemorrhage, and deep periodontal pockets. The teeth were significantly loosened. The mice in the tinidazole group and the recombinant human osteoprotegerin group recovered substantially, and the gingival rating of the recombinant human osteoprotegerin group was better than that. The tinidazole group and the model group (P<0.05). The results of HE staining showed that the model group had edema, vasodilation and a large amount of inflammatory infiltration. The epithelial structure of the mice in the tinidazole group and the recombinant human osteoprotegerin group was intact and arranged closely and orderly. After intervention, the IL-4 in the tinidazole group and the recombinant human osteoprotegerin group was significantly higher than the model group and IL-6 was significantly lower than the model group (P<0.05), and the recombinant human osteoprotegerin group IL-4 was significantly higher after the intervention. IL-6 was significantly lower in the tinidazole group than in the tinidazole group (P<0.05). After the intervention, the tinidazole group and the recombinant human osteoprotegerin group were significantly reduced, and the recombinant human osteoprotegerin group RAKNL and MCP-1 were significantly lower than the model group (P>0.05). Conclusion: Recombinant human osteoprotegerin combined with tinidazole has a better therapeutic effect on gums and teeth in mice with periodontitis, and can lower the levels of RAKNL and MCP-1 in serum, inhibit bone resorption and protect teeth.

Regulation of osteoprotegerin expression by Notch signaling in human oral squamous cell carcinoma cell line

Objective: To investigate the influence of Notch signaling on osteoprotegerin(OPG)expression in a human oral squamous cell carcinoma cell line.Methods: Activation of Notch signaling was performed by seeding cells on Jagged1 immobilized surfaces. In other experiments, a g-secretase inhibitor was added to the culture medium to inhibit intracellular Notch signaling. OPG m RNA and protein were determined by real-time PCR and ELISA, respectively. Finally, publicly available microarray database analysis was performed using connection up- or down-regulation expression analysis of microarrays software.Results: Jagged1-treatment of HSC-4 cells enhanced HES1 and HEY1 m RNA expression, confirming the intracellular activation of Notch signaling. OPG m RNA and protein levels were significantly suppressed upon Jagged1 treatment. Correspondingly, HSC-4 cells treated with a g-secretase inhibitor resulted in a significant reduction of HES1 and HEY1 m RNA levels, and a marked increase in OPG protein expression was observed.These results implied that Notch signaling regulated OPG expression in HSC-4 cells.However, Jagged1 did not alter OPG expression in another human oral squamous cell carcinoma cell line(HSC-5) or a human head and neck squamous cell carcinoma cell line(HN22).Conclusions: Notch signaling regulated OPG expression in an HSC-4 cell line and this mechanism could be cell line specific.

Increased expression of osteoprotegerin in vascular smooth muscle cells from spontaneously hypertensive rats

Background Osteoprotegerin (OPG) is a secreted protein of the tumor necrosis factor receptor family, which regulates bone mass by inhibiting osteoclast differentiation and activation. Although OPG is expressed ubiquitously and abundantly in many tissues and cell types including vascular cells, the role of OPG in other tissues is unknown.Our previous studies demonstrated that OPG was highly expressed in vascular smooth muscle cells (VSMC) and upregulated during vascular lesion formation. Methods and Results We documented, by Northern blot analysis,that the expression of OPG was more prevalent in the aorta and cultured VSMC from spontaneously hypertensive rats (SI-IR) compared to Wistar-Kyoto rats (WKY). In addition, we found that the expression of Angiotensin II (Ang II)type I receptor (AT1R) in SHR VSMC was at significantly increased levels than in WKY VSMC. Furthermore, Ang II potently induced the expression of OPG in VSMC in a time- and dose-dependent manner through the AT1R signaling pathway. Conclusions OPG expression was substantially greater in SHR VSMC, suggesting that OPG may be an important determinant of vascular remodeling in SHR.

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.

No evidence of circulating autoantibodies against osteoprotegerin in patients with celiac disease

AIM:To investigate risk factors for low bone mineral density(BMD) in celiac disease(CD) patients,focusing on circulating autoantibodies against osteoprotegerin(OPG).METHODS:Seventy asymptomatic CD adult patients on gluten-free diet(GFD) and harbouring persistent negative CD-related serology were recruited.Conventional risk factors for osteoporosis(e.g.,age,sex,menopausal status,history of fractures,smoke,and body mass index) were checked and BMD was assessed by dual energy X ray absorptiometry.Serum calcium and parathyroid hormone(PTH) levels were evaluated.Thirty-eight patients underwent repeat duodenal biopsy.Serum samples from a selected sub-group of 30 patients,who were also typed for human leukocyte antigen(HLA) DQ2 and DQ8 haplotype,were incubatedwith homodimeric recombinant human OPG and tested by western blotting with an anti-OPG antibody after immunoprecipitation.RESULTS:Despite persistent negative CD-related serology and strict adherence to GFD,49 out of the 70(74%) patients displayed low BMD.Among these patients,13(24%) showed osteoporosis and 36(76%) osteopenia.With the exception of age,conventional risk factors for osteoporosis did not differ between patients with normal and low BMD.Circulating serum calcium and PTH levels were normal in all patients.Duodenal mucosa healing was found in 31(82%) out of 38 patients who underwent repeat duodenal biopsy with 20(64%) still displaying low BMD.The remaining 7 patients had an incomplete normalization of duodenal mucosa with 6(84%) showing low BMD.No evidence of circulating antibodies against OPG was found in the serum of 30 celiac patients who were tested for,independent of BMD,duodenal histology,and HLA status.CONCLUSION:If any,the role of circulating autoantibodies against OPG in the pathogenesis of bone derangement in patients with CD is not a major one.

Effect of Osteoprotegerin and XRCC3 Genes Polymorphisms with the Occurrence of Left Ventricular Hypertrophy in Hypertensive Patients

Background: High blood pressure is associated with adverse morphological and functional changes in the cardiovascular system, including left ventricular hypertrophy (LVH). Osteoprotegerin (OPG) is a member of the tumor necrosis factor receptor superfamily of cytokines. X-ray repair cross-complementing protein 3 (XRCC3) is involved in the repair pathway for double-strand breaks (DSBs). We assessed the association of osteoprotegerin and XRCC3 gene polymorphisms with the occurrence of left ventricular hypertrophy in hypertensive patients. Patients and methods: The study included 50 hypertensive patients: 25 with LVH (group A) and 25 without LVH (group B). All cases were subjected to complete history taking and clinical examination. ECG and echocardiography were done. LV mass was calculated to detect the presence or absence of LV hypertrophy. DNA was extracted from blood samples, and then, each DNA sample was amplified in PCRs, to detect osteoprotogrin and XRCC3 gene polymorphisms. Results: Mean age in the cases in group A is 63.12 years and in group B was 58.24 years with statistically significant difference between the two groups. The duration of the disease and SBP revealed statistically significant difference between the two groups. The LV mass index and E/A ratio revealed high statistically significant difference between the two groups. OPG sequence revealed no statistically significant difference between the two groups, but XRCC3 sequence revealed statistically significant difference. The age was a risk factor for LVH. Conclusion: Osteoprotogrin and XRCC3 genes polymorphism mutations may be associated with left ventricular hypertrophy in hypertensive patients.

Osteoprotegerin Secretion by Mevastatin via p38MAPK and NF-kB

Osteoprotegerin (OPG) is a protein produced by many cell types that has the remarkable property of inhibiting bone loss. It does this by binding to the key bone resorptive cytokine, receptor activator of NF-kB ligand (RANKL). This cytokine is produced mainly by osteoblastic cells and is instrumental in osteoclast differentiation. If the ratio of RANKL:OPG increases, bone resorption increases and results in bone loss in diseases such osteoporosis, rheumatoid arthritis and hypercalcaemia of malignancy. Hence, if drugs can be found that increase OPG, this will decrease the activity of osteoclasts and therefore bone resorption. Statins are cholesterol lowering drugs that have recently been shown to increase bone formation in rodents. It was hypothesised from this finding that this could be due to an increase in OPG production. If these commonly prescribed drugs could be used to prevent bone loss or to increase bone formation then this may prove a useful means of reducing fracture risk in patients. Treating Saos-2 osteoblast-like cells in vitro with mevastatin increased OPG production and secretion through the mevalonate pathway. A failure of geranylgeranylation of Rho and/or farnesylation of Ras proteins leads to an increase in PI-3K activation then AKT activation leading to several different signaling pathways such as MAPK’s and NF-kB. NF-kB and p38MAPK inhibitors prevented the statin stimulation of OPG but not the decrease in cell number, suggesting that statins regulate OPG secretion via PI-3K, p38MAPK and NF-kB.

Osteoprotegerin and osteoprotegerin ligand expression during human marrow stromal cell differentiation and their effect on osteoclast formation

Background Osteoprotegerin （OPG） and osteoprotegerin ligand （OPGL） play an important role in human bone metabolism. The aim of this research was to detect the expression of OPG and OPGL during human marrow stromal cells （hMSC） differentiation into osteoblasts （OB）, and to observe their effect on osteoclasts （OC） formation in vitro to investigate bone metabolism mechanisms. Methods hMSCs were obtained from human bone marrow specimens using gradient centrifugation method, before being purified and incubated with differentiation medium to develop along the human osteoblasts （hOB） pathway. Morphology observation, biochemical detection and cell staining were performed during hMSC differentiation. OPG and OPGL mRNA levels were detected by reverse transcription-polymerase chain reaction. OPG and OPGL protein expression were determined by Western blotting. We further obtained OC progenitor cells from mice bone marrow and co-cultured with differentiating MSCs. We assessed the effect of OPG and OPGL on OC formation by identifying tartrate resistant acid phosphatase （TRAP） positive multinuclear cells. Results Optimal hMSC survival and purification were observed, along with stable biochemical indexes. Alkaline phosphatase secretion increased significantly and mineralization nodules appeared in the process of cell differentiation. OPG mRNA and protein level increased significantly, while OPGL mRNA and protein level decreased. Average levels of OPG mRNA and protein were about 2.5-fold higher than the control, while OPGL mRNA and protein levels were reduced by about one-half. In the group co-culturing with undifferentiated MSC or added OPGL, we found TRAP positive and multi- nuclear OC formation. However, OC formation was absent in the group co-culturing with differentiated MSC or added OPG. Conclusions During hMSC differentiation into hOB, OPG secretion increased rapidly and OPGL production decreased significantly. The OPG/OPGL ratio was also increased, while OC formation was inhibited and bone absorption decreased Thus, regulation of the OPG/OPGL ratio may be important in controlling MSC differentiation, OB and OC formation in succession involved in bone metabolism.

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。

丹参酮ⅡA调节骨关节炎小鼠骨代谢的作用机制

目的探讨丹参酮ⅡA(TanⅡA)通过介导Yes激酶相关蛋白(Yes-associated protein,YAP)、核因子-κB受体活化因子配基(receptor activator of nuclear factor-κB ligand,RANKL)/核因子κB受体活化因子(eceptor activator of nuclear factor-κB,RANK)/骨保护蛋白(osteoprotegerin,OPG)调节骨关节炎小鼠骨代谢的作用机制。方法建立骨关节炎小鼠模型,将60只小鼠随机分成假手术组、模型组、TanⅡA低剂量组和TanⅡA高剂量组,每组15只,造模成功后灌胃给药,连续4周。HE和番红O固绿染色观察软骨组织病理损伤并进行Mankin评分。酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)检测血清骨碱性磷酸酶(bone alkaline phosphatase,BALP)、骨钙素(osteocalcin,OC)、Ⅰ型胶原交联羧基末端肽(C-telopeptide of typeⅠcollagen,CTX)、白细胞介素(interleukin,IL)-1β、IL-6、IL-8和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)。蛋白质印迹法(Western blotting)检测基质金属蛋白酶(matrix metalloproteinases,MMPs)、YAP、RANK、RANKL和OPG蛋白。结果TanⅡA可改善小鼠软骨组织病理变化并降低Mankin评分。与假手术组比较,模型组BALP、OC水平下降,CTX、TNF-α、IL-6、IL-1β、IL-8、MMP1、MMP3和MMP13水平升高(P<0.05)。与模型组比较,TanⅡA低剂量组、TanⅡA高剂量组BALP、OC水平升高,CTX、TNF-α、IL-6、IL-1β、IL-8、MMP1、MMP3和MMP13水平降低(P<0.05)。与假手术组比较,模型组小鼠软骨组织中YAP、OPG和RANK蛋白水平下降,RANKL蛋白水平升高(P<0.05);与模型组比较,TanⅡA 2组小鼠软骨组织中YAP、OPG和RANK蛋白水平上升,RANKL蛋白水平下降(P<0.05)。结论TanⅡA可能通过介导YAP、RANK/RANKL/OPG信号通路调控骨关节炎。

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。

OPG/RANKL/RANK信号通路与泛髓系统关系概述

“泛髓”是对中医学“髓”概念丰富外延的概括,包括脑髓、脊髓、骨髓、精髓。在“泛髓”关系中,脑髓为之主,精髓为其重要组成部分,脑髓病变可波及精髓,精髓病变也可影响脑髓。骨保护素信号通路可在全身多个系统、器官中表达,是调节骨代谢的重要信号通路,在调控骨吸收以维持骨量方面发挥不可替代的作用。该信号通路与“泛髓”系统中脑髓及精髓的关系最为紧密,其在脑血管病、骨质疏松症、牙周炎等多种“髓”相关疾病进展过程中起到一定调控作用。多种细胞因子可以通过调节骨保护素信号系统的表达,参与脑髓与精髓病变的相关炎症反应。骨保护素信号系统对钙离子代谢的调节或许是机体精髓代谢的途径之一。参考文献48篇。

银耳多糖对人软骨细胞的增殖效应和抗炎作用

目的:骨关节炎(Osteoarthritis,OA)是一种常见的慢性关节性疾病,本研究旨在探究银耳多糖对骨关节炎细胞模型人软骨细胞T/C-28a2的增殖效应和抗炎作用。方法:通过MTT(3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide)和结晶紫染色实验检测银耳多糖对T/C-28a2细胞增殖活力和细胞毒性的影响;用脂多糖(Lipopolysaccharide,LPS)处理T/C-28a2细胞建立骨炎症模型,酶联免疫吸附测定(Enzyme-linked immunosorbent assay,ELISA)检测药物处理后细胞白介素-6(Interleukin-6,IL-6)的表达;利用蛋白免疫印迹(Western blot)检测药物处理后相关骨保护因子和炎症因子的表达;通过ROS活性氧释放实验检测药物对细胞的氧化应激水平和抗炎症反应。结果:银耳多糖能够促进人软骨细胞T/C-28a2的增殖活力,且没有明显的细胞毒性;使用LPS刺激软骨细胞模拟骨炎症的环境,药物处理后发现银耳多糖和硫酸软骨素处理能减少IL-6分泌从而抑制炎症发生;进一步Western blot检测发现银耳多糖刺激后,相关骨保护因子(Osteoprotegerin,OPG)的表达上调,而促凋亡相关蛋白Bax、细胞外信号调节激酶(Extracellular-signal-regulated kinases,ERK-MAPK)和核内转录因子κB(Nuclear factor-kappaB,NF-κB)的表达下调。活性氧(Reactive oxygen species,ROS)释放实验结果显示,银耳多糖和硫酸软骨素能够抑制细胞内ROS水平,抑制炎症反应的发生。结论:银耳多糖具有抑制骨关节炎的效用,可以在一定程度上保护软骨组织,抵抗细胞凋亡。本研究初步探讨了银耳多糖的抗炎作用及机制,为开发银耳多糖作为抗炎药物提供初步的实验依据。