CSF-1对体外培养人牙囊细胞OPG表达的影响

目的研究集落刺激因子(CSF-1)对体外培养的人牙囊细胞骨保护素(OPG)表达的影响。方法原代培养人牙囊细胞,传代至第3代,制备细胞爬片,进行OPG免疫组化染色;3~6代人牙囊细胞长至80%时,用胰酶消化,离心,重悬,制成单细胞悬液,接种到细胞培养皿,细胞长满至80%时,培养基中加入25ng/ml的CSF-1,孵育0.5、1、3、6h,分别收集上清液,ELISA法检测OPG蛋白分泌量的变化,提取总RNA进行RT-PCR,检测OPG mRNA的表达变化。结果正常人牙囊细胞OPG蛋白表达阳性;25ng/ml的CSF-1可降低人牙囊细胞OPG的表达,共同孵育1h,OPG表达降至最低(P<0.05)。结论牙囊细胞表达OPG,同时在牙齿萌出的特定时期,CSF-1通过下调人牙囊细胞OPG,减弱对破骨细胞形成的抑制作用,促进破骨细胞分化成熟,调节牙齿萌出。     

慢性牙周炎患者龈沟液OPG和RANKL的变化及意义

目的:探讨慢性牙周炎患者龈沟液中核因子-κB受体活化子配体(receptor activator for NF-κB ligand.RANKL)和骨保护素(osteoprotegerin,OPG)的变化及意义.方法:采用滤纸条法收集23例正常对照者和34例慢性牙周炎患者龈沟液(gingival crevicular fluid,GCF)标本,ELISA法测定上清液RANKL和OPG含量,利用Optimas 5.0图像分析软件对检测牙的根尖片进行灰度分析.结果:对照组和慢性牙周炎组临床指标(PD、AL、PLI和SBI)之间存在显著性统计学差异(P<0.01).2组GCF中RANKL、OPG和RANKL/OPG比值之间存在显著性统计学差异(P<0.01).慢性牙周炎组GCF中OPG浓度与PD和AL之间存在负相关关系(分别为P<0.01和P<0.05),RANKL浓度及RANKL/OPG比值与根尖片灰度值之间存在负相关关系(P<0.05).GCF中RANKL和OPG浓度及RANKL/OPG比值与PLI和SBI之间无相关关系(P>0.05).结论:RANKL和OPG在慢性牙周炎患者的牙槽骨组织破坏过程中发挥作用.     

大鼠牙龈组织表达护骨因子和护骨因子配体

目的 观察成年大鼠牙龈组织是否表达护骨因子（Osteoprotegerin,OPG)和护骨因子配体（Osteoprotegerin Ligand,OPGL)，为进一步探讨二者在牙龈组织中表达的生理及病理意义奠定基础。方法 提取成年大鼠牙龈组织总RNA，应用特异引物通过逆转录-聚合酶链式反应（RT-PCR）扩增目的片段，并将其插入pGEM-T载体，测序鉴定。结果 测序表明扩增出的二个目的片段DNA序列与文献报道一致，即为护骨因子和护骨因子配体，护骨因子在大鼠虎龈组织表达水平较高，而护骨因子配体表达水平较低。结论 大鼠虎龈组织表达护骨因子和护骨因子配体，二者表达的相对水平对维持牙槽骨局部骨形成与骨吸收的平衡可能有重要意义。     

人白介素－1β水平与人牙周膜细胞OPG表达关系

目的：检测不同浓度重组人白介素－1β（recombinant human interleukin－1β,rhIL－1β）对体外培养人牙周膜细胞（human periodontal ligament cells,HPDLCs）表达骨保护因子（osteoprotegerin,OPG）的影响,研究rhIL－1β水平对牙周膜细胞骨向分化的作用。方法：正畸需要而拨除的健康前磨牙牙周膜,体外传代培养HPDLCs;ELISA法和RT－PCR法测定不同浓度rhIL－1β（0、5、10、15μg／L）下HPDLCs的OPG分泌量及mRNA表达。结果：ELISA和RT－PCR法检测结果显示,5、10、15μg／L rhIL－1β作用于HPDLCs均会下调其OPG蛋白分泌和mRNA表达。同一时间点与0μg／L对照组比较,5、10、15μg／L组OPG蛋白分泌和mRNA表达依此下调,差异有统计学意义（P＜0．05）。结论：rhIL－1β水平升高会增强对HPDLCs的OPG表达抑制,对牙槽骨健康产生不利影响。     

Molecular mechanisms for bone resorption by gingipains: Degradation of osteoprotegerin by lysine-specific gingipain is a key factor for enhanced osteoclastogenesis

BackgroundPeriodontitis is a chronic inflammatory disease accompanied by alveolar bone loss. Porphyromonas gingivalis, which plays a key role in the etiology of periodontitis, produces cysteine proteases called gingipains to promote proteolysis. Gingipains are classified into two groups based on their cleavage site specificity, specifically arginine-specific gingipains (Rgps) and lysine-specific gingipains (Kgps).HighlightWe found that osteoclast differentiation induced by active vitamin D₃, Toll-like receptor ligands including lipopolysaccharide, and inflammatory cytokines such as tumor necrosis factor-α and interleukin-1β was enhanced by a secreted Kgp in co-cultures of mouse osteoblasts and bone marrow cells, whereas RgpB had no effect on osteoclast differentiation under the same experimental conditions. The effect of Kgp on osteoclast differentiation was completely blocked by an inhibitor of Kgp. Further, osteoprotegerin (OPG), a protein that regulates osteoclast differentiation, was degraded by Kgp. Kgp-mediated osteoclast differentiation was not observed in co-cultures of OPG-deficient osteoblasts and bone marrow cells.ConclusionOur data suggests that degradation of OPG by Kgp is a crucial event in the progression of osteolysis in periodontitis.     

Osteoprotegerin in diabetic osteopathy

AimThe aim of this study is to evaluate the relationship between OPG and the degree of glycaemic control in a population of elderly subjects.Methods and resultsData presented included 172 elderly subjects, of whom 107 were hospitalized for a hip fracture and 65 were non fractured outpatients. All participants received a multidimensional geriatric evaluation and underwent blood sampling. HbA1c, OPG, CTX and OC were measured and DXA scans were performed. Carotid intima-media thickness (IMT) was measured in all outpatients. Diabetic patients had more comorbidities, higher mean values of lumbar spine and femoral neck BMD and T-score, lower circulating levels of OC and CTX, and higher circulating levels of OPG compared to non-diabetic subjects. OPG was directly correlated with HbA1c. This association was most evident in non-fractured elderly subjects. Moreover, diabetic patients with IMT>1.5 mm had greater mean values of OPG than non-diabetic subjects with high IMT and than elderly subjects with IMT < 1.5 mm, with and without T2DM.ConclusionsDiabetic patients have reduced circulating levels of OC and CTX, and elevated serum levels of OPG, suggesting a state of low bone turnover. Reduced bone turnover causes an increase of BMD and could lead to a poor bone quality. OPG and HbA1c were directly correlated and OPG mean values were higher in diabetic patients with poor glucose control. Diabetic osteopathy could be considered a late complication of T2DM, directly related with the degree of glucose control and the duration of the disease.     

血清骨代谢指标与妊娠期高血压疾病的关系

目的探讨血清钙（Ca）、护骨素（OPG）和核因子-κB受体活化子配体（RANKL）水平与妊娠期高血压疾病（HDCP）的关系。方法采用全自动生化分析仪及酶联免疫吸附试验（ELISA）检测49例HDCP患者（补Ca组29例，未补Ca组20例）、16名正常妊娠妇女和15名健康育龄妇女Ca、OPG和RANKL的水平。结果HDCP组血清Ca、OPG、RANKL水平与正常妊娠组及育龄组比较，差异有统计学意义（P〈0．05，P〈0．01）。HDCP组中未补Ca组血清Ca、OPG、RANKL水平与补Ca组及正常妊娠组比较，差异有统计学意义（P〈0．01）。结论HDCP患者Ca、OPG及RANKL水平明显异常，孕妇妊娠中晚期维持血清中Ca浓度非常重要，通过联合检测孕妇血清中Ca、OPG及RANKL可预防HDCP的发生。     

Elevated osteoprotegerin is associated with inflammation, malnutrition and new onset cardiovascular events in peritoneal dialysis patients

Backgrounds

Osteoprotegerin (OPG) is known to regulate bone mineral metabolism and to be also associated with inflammation, cardiovascular disease (CVD) and mortality. Malnutrition-inflammation-atherosclerosis (MIA) syndrome is commonly found and closely linked to mortality in dialysis patients. The aim of this study was to investigate the associations between OPG and MIA syndrome in prevalent peritoneal dialysis (PD) patients.

Methods

Prevalent PD patients for more than 6 months were prospectively followed up from March 2005 to May 2010. At baseline, OPG, hs-CRP, albumin, and %lean body mass (LBM) by creatinine kinetics were checked, and subjective global assessment (SGA) was performed. New-onset cardiovascular events were evaluated during the study period. Based on the median level of OPG, patients were classified as lower OPG (LO) group (n = 88) and higher OPG (HO) group (n = 88).

Results

A total of 176 patients (age 52.0 ± 11.8 years, male 50.6%, duration of PD 105.3 ± 67.2 months) were recruited and followed. In HO group, age, hs-CRP level and Charlson's comorbidity indices were higher, whereas serum albumin level, %LBM and SGA score were significantly lower than LO group. OPG levels were positively correlated with inflammatory markers, whereas negatively correlated with nutritional status. Cardiovascular events occurred in 51 patients during the study period. Newly developed cardiovascular events were significantly common in HO group (n = 36, 40.9%) than LO group (n = 15, 17%, p = 0.002). Cox regression analysis revealed that higher OPG level (per 1-SD increase in OPG, HR: 1.44; 95% CI: 1.03–2.00; p = 0.034) was a significant risk factor for cardiovascular events even after adjustments for demographic and biochemical parameters.

Conclusion

OPG was significantly correlated with markers of systemic inflammation and malnutrition and was a significant predictor of CVD in PD patients. These findings suggest OPG might be a prognostic indicator of MIA syndrome in prevalent PD patients.