Use of recombinant human bone morphogenetic protein-2 in spine surgery

Bone morphogenetic proteins are osteoinductive factors which have gained popularity in orthopaedicsurgery and especially in spine surgery. The use of recombinant human bone morphogenetic protein-2 has been officially approved by the United States Food and Drug Administration only for single level anterior lumbar interbody fusion, nevertheless it is widely used by many surgeons with off-label indications. Despite advantages in bone formation, its use still remains a controversial issue and several complications have been described by authors who oppose their wide use.

Implantation of xenogeneic bone combined with recombinant human bone morphogenetic protein-2 into bone defect—An scanning electron microscopic study

To determine the ability of a new type of composite xenogeneic bone grafting to repair bone defect. Methods: The new type of composite xenogeneic bone was obtained by combining the chemically treated cance1lous bone with recombinant human bone morphogenetic protein-2 (rhBMP-2). It was implanted on the bone defect of rabbit. Results: There was a large amount of new bone formation within the combined material and the amount was increasing as the time elapsed. In contrast, there was a lot of fibrous tissue with a little new bone formed on the area of the bone defect when the treated cancellous bone was implanted alone. Conclusion: The results imply that the rhBMP-2 plays a very important role in new bone formation and the composite xenogeneic bone appear to be an ideal material for repair of bone defect.

CORAL AS A CARRIER FOR RECOMBINANT HUMAN BONE MORPHOGENETIC PROTEIN-2

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EFFECTS OF TRANSFORMING GROWTH FACTOR β AND RECOMBINANT HUMAN BONE MORPHOGENETIC PROTEIN 2 ON HUMAN PERIODONTAL LIGAMENT FIBROBLASTS

Objective To evaluate the effects of transforming growth factor β(TGF-β) and recombinant human bone morphogenetic protein 2 (rhBMP2) on human periodontal ligament fibroblasts (HPDLFs). Methods HPDLFs were done primary culture to detect the distinct concentrations of TGF-P and rhBMF2 on its proliferation, alkaline phosphatase (ALP) activity, osteocalcin (OC) synthesis and formation of the minerali-zed nodules, respectively. Results TGF-β (5～100ng/ml) significantly stimulated the proliferation of HPDLFs. The ALP activity of HPDLFs was evaluated evidently by 5ng/ml TGF-β. TGF-β( 0. 5 ～ 100ng/ml) had no effects on OC synthesis and formation of the mineralized nodules of HPDLFs. rhBMP2 (0. 25～2mg/ ml) had no remarkable effect on the proliferation of HPDLFs. The ALP activity, OC synthesis and forma-tion of the mineralized nodules of HPDLFs were significantly stimulated by 0. 5～ 2mg /ml rhBMP2. Conclusion The effects of TGF-β and rhBMP2 on HPDLFs are dose-dependent. TGF-P can stimulate HPDLFs to express the early marker of osteoblastic phenotype, and it lacks the ability to promote maturation of the osteogenic phenotype. rhBMP2 can not only stimulate the expression but also promote the maturation of osteoblas-tic phenotype of HPDLFs.

Heterotopic ossification after the use of recombinant human bone morphogenetic protein-7

AIM To present the incidence of heterotopic ossification after the use of recombinant human bone morphogenetic protein-7(rhB MP-7) for the treatment of nonunions.METHODS Bone morphogenetic proteins(BMPs) promote bone formation by auto-induction. Recombinant human BMP-7 in combination with bone grafts was used in 84 patients for the treatment of long bone nonunions. All patients were evaluated radiographicaly for the development of heterotopic ossification during the standard assessment for the nonunion healing. In all patients(80.9%) with radiographic signs of heterotopic ossification, a CT scan was performed. Nonunion site palpation and ROM evaluation of the adjacent jointswere also carried out. Factors related to the patient(age, gender), the nonunion(location, size, chronicity, number of previous procedures, infection, surrounding tissues condition) and the surgical procedure(graft and fixation type, amount of rhB MP-7) were correlated with the development of heterotopic ossification and statistical analysis with Pearsons χ~2 test was performed.RESULTS Eighty point nine percent of the nonunions treated with rh BMP-7, healed with no need for further procedures. Heterotopic bone formation occurred in 15 of 84 patients(17.8%) and it was apparent in the routine radiologi-cal evaluation of the nonunion site, in a mean time of 5.5 mo after the rh BMP-7 application(range 3-12). The heterotopic ossification was located at the femur in 8 cases, at the tibia in 6, and at the humerus in οne patient. In 4 patients a palpable mass was present and only in one patient, with a para-articular knee nonunion treated with rhB MP-7, the size of heterotopic ossification affected the knee range of motion. All the patients with heterotopic ossification were male. Statistical analysis proved that patient's gender was the only important factor for the development of heterotopic ossification(P = 0.007). CONCLUSION Heterotopic ossification after the use of rh BMP-7 in nonunions was common but it did not compromise the final clinical outcome in most cases, and affected only male patients.

Expression of mature peptide of human bone morphogenetic protein-2 in Escherichia coli

To express die mature peptide of human bone morphogenetic protein-2 in Escherichia coil. Methods: TheDNA fragment encoding the mature peptide of human bone morphogenetic protein-2 (hBMP-2m) was inserted into expression vectorpDH in which foreign gene was controlled by PRPL promoters. E. coli DH5a transformed with recombinant plasmid pDHB2m wasinduced at 42℃to express the target protein. The expressed product was partially purified and refolded, and then implanted intorat thigh muscles to assay its bone inductive activity. Results: After induction, a protein band on SDS-PAGE gel with an apparentmol. wt. of 13kD was observed to anticipate in the strain carrying pDHB2m, but not in the control. The expressed hBMP-2m accounted for 45%-60% of the total bacterial protein. The expressed product existed in a form of inclusion body. After partially purified and refolded, rhBMP-2m could induce the formation of cartilage and bone tissue heterotopically. Conclusion: The maturepeptide of human bone morphogenetic protein-2 has ben successfully expressed in E. coli and the product has ectopic bone inductive activity.

Construction of bicistronic green fluorescent protein labeled pSELECT GFPzeo human bone morphogenetic protein 2 eukaryotic expression vector

Objective To construct green fluorescent protein (GFP)-labeled pSELECT-GFP zeohBMP2 eukaryotic expression vector.Methods The encoding fragment of hBMP2 gene was obtained from a recombinant plasmid pcDNA3.1/CT-hBMP2 by using polymerase

含重组人碱性成纤维细胞生长因子和重组人骨形态发生蛋白-2骨水泥在骨质疏松性腰椎压缩性骨折治疗的应用价值

目的:探讨含重组人碱性成纤维细胞生长因子(recombinant human basic fibroblast growth factor,rhbFGF)和重组人骨形态发生蛋白-2(recombinant human bone morphogenetic protein-2,rhBMP-2)骨水泥在骨质疏松性腰椎压缩性骨折(osteoporotic vertebral compression fracture,OVCF)患者经皮椎体后凸成形术(percutaneous kyphoplasty,PKP)治疗的应用价值。方法:回顾性分析2018年1月至2021年1月收治的103例行PKP手术治疗的OVCF患者,男40例,女63例;年龄61~78(65.72±3.29)岁。受伤原因:滑倒33例,跌倒42例,提重物受伤28例。根据填充骨水泥不同分为3组:磷酸钙组34例,男14例,女20例,年龄(65.1±3.3)岁,填充磷酸钙骨水泥;rhBMP-2组34例,男12例,女22例,年龄(64.8±3.2)岁,填充含rhBMP-2的骨水泥;rhbFGF+rhBMP-2组35例,男14例,女21例,年龄(65.1±3.6)岁,填充含rhbFGF和rhBMP-2的骨水泥。比较3组Oswestry功能障碍指数(Oswestry dysfunction index,ODI)、骨密度、椎体前缘丢失高度、伤椎前缘压缩率、疼痛视觉模拟评分(visual simulation score,VAS)及再骨折发生率。结果:所有患者获得12个月随访。3组术后ODI、VAS呈下降(P<0.001),骨密度增高(P<0.001),椎体前缘丢失高度、伤椎前缘压缩率呈先下降后缓慢上升趋势(P<0.001),rhbFGF+rhBMP-2组术后第1、6、12个月ODI、VAS均低于rhBMP-2组和磷酸钙组(P<0.05),术后第6、12个月骨密度大于rhBMP-2组和磷酸钙组(P<0.05)。rhbFGF+rhBMP-2组术后第6、12个月椎体前缘丢失高度、伤椎前缘压缩率均低于rhBMP-2组和磷酸钙组(P<0.05)。3组再骨折发生率比较差异无统计学意义(P>0.05)。结论:含rhbFGF和rhBMP-2骨水泥可更有效地增加OVCF患者骨密度,获得术后满意的临床和放射学效果,显著改善临床症状。

负载骨形态发生蛋白2水凝胶诱导牙髓干细胞的成骨分化

背景:前期研究证明,甲基丙烯酸酐改性明胶/经处理牙本质基质复合水凝胶支架可促进人牙髓干细胞的增殖及分化。水凝胶负载骨形态发生蛋白2被认为是骨修复中有前景的材料。目的:观察负载不同质量浓度骨形态发生蛋白2的甲基丙烯酸酐改性明胶/经处理牙本质基质复合水凝胶对人牙髓干细胞成骨向分化的诱导作用。方法:制备含0,50,100,200μg/mL骨形态发生蛋白2的甲基丙烯酸酐改性明胶/经处理牙本质基质复合水凝胶,分别记为GelMA/TDM、BMP-2(50 ng/mL)GelMA/TDM、BMP-2(100 ng/mL)GelMA/TDM、BMP-2(200 ng/mL)GelMA/TDM,检测复合水凝胶对骨形态发生蛋白2的体外缓释性能。采用改良组织块酶消化法提取人牙髓干细胞,分别接种于4种水凝胶表面,采用CCK-8法检测细胞增殖,DAPI染色检测细胞黏附;对各组水凝胶表面的人牙髓干细胞进行成骨诱导,进行碱性磷酸酶染色、碱性磷酸酶活性检测与茜素红染色,采用RT-PCR法检测相关成骨基因(Runx2、骨形态发生蛋白2、骨桥蛋白、骨钙素、Ⅰ型胶原)表达。结果与结论:①甲基丙烯酸酐改性明胶/经处理牙本质基质复合水凝胶可持续释放骨形态发生蛋白2长达21 d,在第3-6天释放较快,第6天之后释放趋于平稳;②4种水凝胶均可促进人牙髓干细胞的增殖,其中以BMP-2(100 ng/mL)-GelMA/TDM复合水凝胶的作用最明显;相较于GelMA/TDM复合水凝胶,BMP-2-GelMA/TDM复合水凝胶可促进人牙髓干细胞的黏附,其中以BMP-2(200 ng/mL)-GelMA/TDM复合水凝胶的作用最明显;③相较于GelMA/TDM复合水凝胶,BMP-2-GelMA/TDM复合水凝胶可提升碱性磷酸酶活性、钙结节含量与相关成骨基因表达,综合分析显示BMP-2(100 ng/mL)-GelMA/TDM复合水凝胶的作用更明显;④结果表明,BMP-2(100 ng/mL)-GelMA/TDM复合水凝胶促进牙髓干细胞成骨向分化的能力更明显。

重组人骨形态发生蛋白-2用于骨壁缺损拔牙位点保存的效果

目的:评价重组人骨形态发生蛋白-2(recombinant bone morphogenetic proteinrh-2,rhBMP-2)用于骨壁缺损拔牙位点保存的临床效果。方法:2019年2月~2023年1月将符合条件的142例患者随机分组,A组使用rhBMP-2+胶原蛋白海绵填充拔牙窝,B组使用胶原蛋白海绵,C组不使用移植物。于拔牙后18周、24周开展种植手术,并编为A1、A2;B1、B2;C1、C2组,种植术中发现有牙槽嵴顶骨缺损的病例测量牙槽嵴缺损的最大近远中径(L)、颊舌径(W)及深度(H),计算体积(V)值(V=L×W×H);无牙槽骨顶骨缺损的病例取种植窝骨块进行组织学分析。结果:A1、A2组牙槽嵴顶骨缺损的发生频率分别为:0.32、0.14;B1、B2组分别为:0.75、0.43;C1、C2组分别为:0.72、0.37。A1B1组间、A2B2组间、A1C1组间及A2C2组间V值差异有统计学意义(P<0.05)。A1B1组间及A1C1组间新生骨占比差异有统计学意义(P<0.05)。结论:rhBMP-2用于骨壁缺损的拔牙位点保存可缩短成骨时间(18周),减少不良愈合的发生,为后期种植手术的开展创造更有利的骨条件。

Human bone marrow mesenchymal stem cell transplantation attenuates axonal injury in stroke rats

Previous studies have shown that transplantation of human bone marrow mesenchymal stem cells promotes neural functional recovery after stroke, but the neurorestorative mechanisms remain largely unknown. We hypothesized that functional recovery of myelinated axons may be one of underlying mechanisms. In this study, an ischemia/reperfusion rat model was established using the middle cerebral artery occlusion method. Rats were used to test the hypothesis that intravenous transplantation of human bone marrow mesenchyrnal stem cells through the femoral vein could exert neuroprotective effects against cerebral ischemia via a mechanism associated with the ability to attenuate axonal injury. The results of behavioral tests, infarction volume analysis and immunohistochemistry showed that cerebral ischemia caused severe damage to the myelin sheath and axons. After rats were intravenously transplanted with human bone marrow mesenchymal stem cells, the levels of axon and myelin sheath-related proteins, including microtubule-associated protein 2, myelin basic protein, and growth-associated protein 43, were elevated, infarct volume was decreased and neural function was improved in cerebral ischemic rats. These findings suggest that intravenously transplanted human bone marrow mesenchymal stem cells promote neural function. Possible mechanisms underlying these beneficial effects include resistance to demyelination after cerebral ischemia, prevention of axonal degeneration, and promotion of axonal regeneration.

Bone Regeneration Enhanced by Antigen-Extracted Xenogeneic Cancellous Bone Graft with rhBMP-2 in Rabbits Mandibular Defect Repair

The effects of large piece xenogeneic bone which was separated from healthy pigs as a scaffold on repair of mandibular defect was investigated and the applicability of antigen-extracted xenogeneic cancellous bone (AXCB) soaked with rhBMP-2 in bone defect repair was assessed. Mandibular defects were created in 48 New Zealand Rabbits, and then randomly divided into 4 groups, which was grafted in the mandibular defects with AXCB, AXCB soaked with rhBMP-2, autograft bone, or blank. Equal number of animals from each group was classified into three time points (4, 8, and 12 weeks) after operation for gross pathological observation, hematoxylin and eosin (H & E) staining, radiographic examination, and bone density measurement. H & E staining revealed that the area percentage of bone regeneration in the group of AXCB/rhBMP-2 graft was 27.72 ± 4.68, 53.90 ± 21.92, and 77.35 ± 9.83 when at 4, 8, and 12 weeks, which was better than that of auto bone graft, prompting that the group of AXCB/rhBMP-2 graft had commendable osteogenic effect. And comparing with the AXCB without rhBMP-2, of which the area percentage of bone regeneration was only 14.03 ± 5.02, 28.49 ± 11.35, and 53.90 ± 21.92, the osteogenic effect of AXCB/rhBMP-2 graft was demonstrated to be much better. In the group of AXCB/rhBMP-2 graft, the area percentage of bone regeneration increased, and the implanted materials were gradually degraded and replaced by autogenous bone regeneration over time. We concluded that antigen-extracted xenogeneic cancellous bone (AXCB) graft soaked with rhBMP-2 had shown excellent osteogenic effect in repair of bone defects, with good biocompability.

Bcl-2 over-expression and activation of protein kinase C suppress the Trail-induced apoptosis in Jurkat T cells

Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role, like FasL in activation-induced cell death (AICD), has been demonstrated in immune system. However the mechanism of Trail induced apoptosis remains nuclear. In this report, the recombinant Trail protein was expressed and purified. The apoptosis-inducing activity and the regulation mechanism of recombinant Trail on Jurkat T cells were explored in vitro. Trypan blue exclusion assay demonstrated that the recombinant Trail protein actively killed Jurkat T cells in a dose-dependent manner. Trail-induced apoptosis in Jurkat T cells were remarkably reduced by Bcl-2 over expression in BcL-2 gene transfected cells. Treatment with PMA (phorbol 12-myristate 13-acetate), a PKC activator, suppressed nail-induced apoptosis in Jurkat T cells. The inhibition of apoptosis by PMA was abolished by pretreatment with Bis, a PKC inhibitor. Taken together, it was suggested that Bcl-2 over-expression and PMA activated PKC actively down-regulated the Trail-mediated apoptosis in Jurkat T cell.

Capacity of bone induction of compound material of decalcified bone matrix combined with rhBMP-2 and impregnated with bone cement

AIM:To analyze bone inductive capacity of the compound material of decalcified bone matrix combined with rhBMP 2 and impregnated with bone cement.METHODS:To assess the experimental study, histological and Masson’s methods were used.RESULTS:The effects of compound material on the induction of bone formation were investigated in NIH mouse models.It was observed that in the with rhBMP 2 group, mesenchymal cells gathered in the implanted material at the 7th day postoperation,chondrogenesis were found at 14 to 21 days after implantation,new bone formation were observed at about 21 to 28 days after surgery and the DBM particles were absorbed by the new generated tissues gradually.CONCLUSIONS:The compound material of DBM combined with rhBMP 2 and impregnated with bone cement could induce the proliferation and migration of mesenchymal tissues that could be differentiated into cartilage and formed new bone finally.The new bone could absorb DBM particles gradually.The compound material had fair capacity of bone induction.

Transepithelial transport of putrescine across monolayers of the human intestinal epithelial cell line, Caco-2

AIM To study the transepithelial transport characteristics of the polyamine putrescine in human intestinal Caco-2 cell monolayers to elucidate the mechanisms of the putrescine intestinal absorption.METHODS The transepithelial transport and the cellular accumulation of putrescine was measured using Caco 2 cell monolayers grown on permeable filters.RESULTS Transepithelial transport of putrescine in physiological concentrations (>0.5 mM)from the apical to basolateral side was linear. Intracellular accumulation of putrescine was higher in confluent than in fully differentiated Caco-2 cells, but still negligible (less than 0.5%) of the overall transport across the monolayers in apical-to-basolateral direction. EGF enhanced putrescine accumulation in Caco-2 cells by four-fold, as well as putrescine conversion to spermidine and spermine by enhancing the activity of Sadenosylmethionine decarboxylase. However,EGF did not have any significant influence on putrescine flux across the Caco-2 cell monolayers. Excretion of putrescine from Caco-2cells into the basolateral medium did not exceed 50 picomoles, while putrescine passive flux from the apical to the basolateral chamber,contributed hundreds of micromoles polyamines to the basolateral chamber.CONCLUSION Transepithelial transport of putrescine across Caco-2 cell monolayers occurs in passive diffusion, and is not influenced when epithelial cells are stimulated to proliferate by a potent mitogen such as EGF.

负载rh-BMP2的羟基磷灰石人工骨治疗胫骨平台骨折骨缺损的临床疗效研究

目的通过与羟基磷灰石生物陶瓷人工骨对比,评估负载rh-BMP2的羟基磷灰石人工骨对胫骨平台骨折骨缺损修复的临床疗效。方法回顾性分析2014年10月至2019年9月中国人民解放军联勤保障部队第九二〇医院骨科收治的53例SchatzkerⅤ、Ⅵ型胫骨平台骨折骨缺损患者,所有患者均进行骨折切开复位内固定术并予术中植骨,其中27例患者术中予负载rh-BMP2的羟基磷灰石人工骨植骨(研究组),另26例患者予羟基磷灰石生物陶瓷人工骨植骨(对照组)。对比两组患者骨折愈合时间、膝关节HSS功能评分、Rasmussen影像学评分及术后并发症发生情况。结果所有患者获得随访,平均随访时间为(10.45±2.31)个月,所有患者最终均骨性愈合。研究组的骨折愈合时间[(13.46±3.38)周]明显短于对照组[(16.67±6.51)周](P<0.05);术后6个月时研究组HSS评分[(85.53±5.30)分]优于对照组[(80.58±6.40)分](P<0.05)。术后6个月时两组的Rasmussen影像学评分比较,差异无统计学意义(P>0.05),同时两组患者随访期间出现并发症情况比较,差异无统计学意义(P>0.05)。结论相较于羟基磷灰石人工骨治疗胫骨平台骨折骨缺损,负载rh-BMP2的羟基磷灰石人工骨植入后骨折愈合时间更短,膝关节功能恢复更佳,同时未增加并发症发生风险。其可视为一种良好的人工骨修复材料。

Therapeutic effects of human umbilical cord-derived mesenchymal stem cells against acute tubular necrosis quantified through measures of iNOS, BMP-7 and Bcl-2

Introduction: Acute tubular necrosis (ATN) is the most prevalent cause of acute renal failure (ARF). Mesenchymal stem cell transplantation has been studied as a potential treatment for renal dysfunction due to ATN. Inducible nitric oxide synthase (iNOS), bone morphogenetic protein-7 (BMP-7) and B-cell lymphoma 2 (Bcl-2) are surrogate markers of renal tubular epithelial regeneration and subsequent recovery of renal function following ATN. Methods: Serum creatinine (Scr) and blood urea nitrogen (BUN), as well as expression of iNOS, BMP-7 and Bcl-2 in gentamycin-induced ATN rat kidneys was investigated after human umbilical cord-derived mesenchymal stem cell (HUC-MSC) transplantation. Immunohistochemical staining was performed in 3 groups of rats: gentamycin-induced ATN treated with HUC-MSC, gentamycin-induced ATN without HUC-MSC, and untreated rats not receiving any treatments. Results: HUC-MSC transplantation led to a reduction in Scr and BUN in the kidneys of rats with gentamycin-induced ATN. Expression of iNOS in the HUC-MSC treated group occurred later and the expression levels were much lower during gentamycin-induced ATN compared to rats with ATN that were not treated with HUC-MSC. The expression of BMP-7 and Bcl-2 in the MSC-transplanted group was significantly increased compared to both control groups of rats with injured and healthy renal tubules. Conclusions: HUC-MSCs induce renal protection in a rat model of gentamycin-induced ATN, which is associated with reduced iNOS expression and up-regulation of Bcl-2 and BMP-7.

重组人骨形态发生蛋白-2联合股骨近端髓内钉内固定术治疗老年骨质疏松股骨粗隆间骨折的效果

目的:观察骨质疏松性粗隆间骨折术中于骨折局部植入重组人骨形态发生蛋白-2(rhBMP-2)治疗的效果。方法:选择2020年至2022年包头医学院第一附属医院创伤二科接收的144例患者,均为骨质疏松性粗隆间骨折,采用随机数字表法分为两组,每组72例。对照组给予单纯骨折复位[股骨近端髓内钉系统(PFNa)内固定术],观察组在对照组采用相同手术方式基础上联合术中局部植入rhBMP-2,通过分析两组患者随访期6个月内骨折愈合时间、骨折愈合率、疼痛数字评分(NRS评分)、髋关节功能评分(Harris评分)、死亡率、住院时间等变量数据对比观察患者术前后并发症、不良反应及治疗效果。结果:观察组骨折愈合率,髋关节功能评分均较对照组有所提升(P<0.05);观察组骨折愈合时间与对照组相比显著缩短(P<0.05);观察组并发症发生比率及死亡比率均较对照组降低(P<0.05);疼痛数字评分(NRS评分),住院时间两组之间对比无统计学意义(P>0.05)。结论:PFNa内固定术治疗骨质疏松性粗隆间骨折联合rhBMP-2经加压铰刀钉道植入术治疗效果显著,对促进患者髋关节功能恢复及减少并发症的发生具有较大意义。

周期性牵张力通过调控BMP2对人牙周膜成纤维细胞成骨分化的初步研究

目的探究周期性牵张力对人牙周膜成纤维细胞(human periodontal ligament fibroblasts,hPDLFs)中骨形态发生蛋白-2(bone morphogenetic protein-2,BMP-2)表达的影响及对人牙周膜成纤维细胞(human periodontal ligament fibroblasts,hPDLFs)成骨分化的作用。方法体外培养hPDLFs,分为3组(空白对照组、6 h组、12 h组),分别不加力、加力6 h和12 h。使用免疫荧光实验检测3组细胞骨架蛋白表达情况;使用Western Blot实验检测3组BMP-2表达情况;碱性磷酸酶染色试剂盒及茜素红染色实验分别用于检测3组碱性磷酸酶(alkaline phosphatase,ALP)活性及骨钙结节形成情况。结果免疫荧光实验结果显示6 h组、12 h组hPDLFs骨架蛋白表达明显高于空白对照组;Western Blot实验结果显示6 h组、12 h组BMP-2蛋白表达明显高于空白对照组且具有统计学意义(P<0.05);ALP染色实验结果显示6 h组、12 h组中ALP活性明显高于空白对照组;茜素红染色实验结果显示6 h组、12 h组骨钙结节形成明显高于空白对照组。结论周期性牵张力的施加会促进hPDLFs中BMP-2的表达并促进hPDLFs成骨分化,可为临床口腔正畸进一步提供理论依据。

骨形态发生蛋白2对人尿源性干细胞骨向分化的影响

目的探讨骨形态发生蛋白2(BMP2)对人尿源性干细胞(hUSCs)骨向分化的影响,并研究其相关机制。方法体外提取hUSCs,利用流式细胞仪检测表型CD29、CD90、CD73、CD44、CD34及CD45;利用10-7~10-5mol/L浓度的BMP2干预hUSCs,Western blot检测骨性标志物碱性磷酸酶(ALP)和Runt相关转录因子2(Runx2);利用基因沉默干扰腺苷酸活化蛋白激酶(si-AMPK),并检测骨性标志物表达。建立大鼠颅骨缺损模型,通过将细胞附着在骨织工程修复支架β-磷酸三钙(β-TCP)植入颅骨缺损模型,1个月后micro CT检测新骨体积和新骨厚度并利用病理学观察新骨结构。结果流式细胞仪检测结果显示,hUSCs高表达CD29、CD90、CD73、CD44,低表达CD34、CD45;并且BMP2在10-6mol/L对hUSCs具有最佳促进成骨效果。Western blot显示,si-AMPK能有效抑制BMP2诱导的骨性标志物ALP和Runx2表达。体内实验结果显示,BMP2能有效促进新骨形成,而si-AMPK能有效抑制新骨形成。结论BMP2在体内外均能有效促进hUSCs骨向分化,可能是通过激活AMPK途径发挥作用。