GDF-5体外转染BMSCs移植修复兔退变椎间盘的实验研究

目的 通过骨髓间充质干细胞(BMSCs)体外生长分化因子-5(GDF-5)基因转染修饰,然后移植入退变的椎间盘中,观察修复椎间盘退变的效果.方法 脂质体介导的pcDNA3.1(+)/GDF-5重组质粒转染兔BMSCs,G418筛选稳定表达株;实验分为转染细胞组、BMSCs组、退变组,2个月后RT-PCR观察椎间盘髓核细...     

GDF-5基因体外转染骨髓间充质干细胞移植与GAM体内转染对椎间盘退行性变作用的动物实验研究

目的通过对比体外生长分化因子5(GDF-5)转染并移植和基因活化基质(GAM)体内转染对椎间盘退行性变的修复作用,评价这两种方法的差异,以期为临床应用提供依据。方法日本大耳白兔32只,体质量约1.5~2.0kg,雌雄不限。取兔骨髓,分离骨髓间充质干细胞(BMSC),用脂质体介导的pcDNA3.1(+)/GDF-5基因重组质粒转染BMSC。将兔随机分为A组(正常组)、B组(转染细胞组)、C组(GAM组)、D组(对照组)。B、C、D组从L1-2、L2-3、L3-4、L4-5抽吸约湿质量5mg的髓核组织,制作椎间盘退行性变动物模型;B组植入已转染GDF-5的BMSC,C组植入GDF-5GAM,D组植入空白培养液。术后2个月将包括软骨终板在内的各组完整的椎间盘取出,采用间苯三酚法测量椎间盘髓核中蛋白多糖含量,采用流式细胞仪检测分析髓核细胞凋亡率。结果转染48 h后BMSC生长良好,体积略增大。经测定pcDNA3.1(+)/GDF-5基因转染成功后髓核内蛋白多糖含量,B组(0.2169±0.0264)与A组(0.2401±0.0300)间差异无统计学意义(P=0.149);其余组(C组、D组分别为0.1667±0.0278、0.1153±0.033 7)两两比较,差异都有显著的统计学意义(P0.01)。髓核细胞凋亡率,A组(24.55%±2.681%)与B组(30.980%±2.462%)间差异具有统计学意义(P=0.012),其余各组(C组、D组分别为38.220%±2.524%、57.530%±2.349%)两两相比,差异都有显著统计学意义(P0.01)。结论相对于利用GAM进行体内转染,体外转染BMSC然后再移植入体内的方法修复椎间盘退行性变的效率更高。     

兔椎间盘退变与修复模型的研究现状*

椎间盘退变模型是研究椎间盘退变疾病的基础和关键之一。兔退变椎间盘模型具有操作简单、可重复性好等特点被国内外学者广泛应用。兔椎间盘退变模型包括体内模型、体外模型等。体内模型根据损伤类别包括:机械损伤模型、化学损伤模型、异常应力模型、脊柱不稳模型、脊柱融合模型等;体外模型包括椎间盘细胞模型、椎间盘组织模型等。本文根据近年兔腰椎间盘各种退变模型与修复的研究现状与进展作一综述。     

基质金属蛋白酶与椎间盘的退变

背景：椎间盘细胞外基质的破坏是椎间盘退变的主要标志,已经证实这与主要基质金属蛋白酶的表达和活性上调有关。然而到目前为止对于基质金属蛋白酶家族的调节几乎没有系统的资料。 目的：全面了解基质金属蛋白酶在椎间盘退变中的表达及作用。 方法：由第一作者用计算机检索中国生物医学全文数据库(SinoMed：2000/2011)和Medline数据库(2000/2011),检索词分别为“基质金属蛋白酶,基质金属蛋白酶组织抑制因子,椎间盘,退行性变,脊柱”和“matrix metalloproteinases,tissue inhibitor of matrix metalloproteinases,disc,degeneration,intervertebral”。共检索到207篇文章,按纳入和排除标准对文献进行筛选,共纳入31篇文章。回顾收录的基质金属蛋白酶相关综述和论文报告,并分析生物学作用及调节的研究进展。 结果与结论：基质金属蛋白酶在椎间盘退变中起着重要作用,已有证据表明基质金属蛋白酶能加速椎间盘细胞外基质的退变进程,并已取得了大量免疫组化证据的支持。     

低温等离子消融术建立兔椎间盘退变模型的实验研究

目的　探讨低温等离子消融术建立兔椎间盘退变模型的方法与可行性。 方法　新西兰大白兔24只,随机分为实验组12只,对照组12只。两组均穿刺L3/4～L5/6椎间隙,实验组采用消融30s建模,对照组单纯以穿刺针穿刺建模。分别于术前及术后4、8、12周行CR、MRI检查及病理学检查。 结果　实验组DR及MR检查至术后12周均可见退变逐步加重的征象,如椎间隙高度的丢失及T2信号逐步降低。对照组DR及MR检查4周后无明显的退变加重迹象。两组病理学检查均未见早期的髓核缺失,实验组12周可见髓核正常结构消失,椎间盘内结构紊乱。 结论　低温等离子消融术比传统单纯穿刺更易及快速建立椎间盘退变的动物模型,采用此方法建立兔椎间盘退变模型是可靠可行的。     

转染hIGF-1基因增强兔退变椎间盘蛋白多糖的表达

目的 探讨人胰岛素样生长因子(hlGF-1)基因在退变椎间盘中的表达及对椎间盘中蛋白多糖(agglecan)的影响.方法 制备新西兰大白兔腰椎间盘退变(IDD)模型24只,随机分为Ad/CMV.hlGF-1、hlGF.1生长因子及PBS组,每组8只.IA-5、L5-6椎间盘中分别注射第2代Ad/CMV-hlGF-1(8×108PFU)、hlGF-1生长因子(100μg/L)、PBS均25μL.注射后1、2.4和8周,Western blot检测hlGF-1蛋白表达;RT-PCR检测aggrecan mRNA的表达.结果 hlGF-1蛋白带出现在7.6×103ku.Ad/CMV-hlGF-1组hIGF-I蛋白表达持续达4周以上,hIGF-1组表达持续约2周;PBS注射组无hIGF-1蛋白表达.aggrecan电泳条带出现在200～300 bp;在注射后1～4周,Ad/CMV-hlGF-I组内aggrecan mRNA相对表达量进行性增加,8周轻度下降,4个时期总的比较(F=8.51,P<0.05),注射后1～8周,hlGF-1组、PBS组aggrecan mRNA相对表达量进行性下降.结论 hlGF-1能够增强椎间盘aggrecan的表达.     

退变椎间盘细胞外基质的改变

细胞外基质(extracellular matrix，ECM)是指位于上皮或内皮细胞下层、结缔组织细胞周围，为组织、器官甚至整个机体的完整性提供力学支持和物理强度的物质。ECM是一种动态物质，不仅仅是细胞机械支持组织，而且是供给营养和免疫应答的场所，参与调节胚胎发育进程，决定细胞的粘附与迁移，在创伤修复和纤维化、细胞的生长、分化、代谢和肿瘤发生及转移中起重要作用。     

椎间盘退变模型的研究进展

椎间盘退变疾病发病率越来越高,但退变的机制尚不明确.椎间盘退变模型是现今研究椎间盘退变疾病的主要方式,退变模型主要分为体内退变模型和体外退变模型两大类.两种退变模型从不同角度研究椎间盘退变的病理生理过程,为揭示退变机制及预防、治疗椎间盘退变疾病起着重要作用.本文就目前国内外关于两种不同椎间盘退变模型研究的进展作一综述.     

兔退变椎间盘中BNIP3的免疫组织化学研究

目的探讨兔退变椎间盘中BNIP3蛋白的表达情况。方法建立兔椎间盘穿刺退变模型,分别培养2、4、8周后对目的椎间盘进行组织HE染色、番红O染色及BNIP3免疫组织化学染色,与正常椎间盘随机对照,检测椎间盘退变程度及BNIP3蛋白表达情况。结果成功建立兔椎间盘退变模型,随椎间盘退变程度加重,BNIP3蛋白在中央髓核组织中的阳性表达逐渐增强。结论兔椎间盘退变过程中,BNIP3蛋白表达增强诱导髓核细胞死亡增加。     

人生长分化因子-5完整成熟肽基因的克隆

目的：克隆人生长分化因子-5(hGDF-5)完整成熟肽基因。方法：根据Genbank中hGDF-5的序列化学合成两条引物，从人胎儿软骨组织提取总RNA，通过反转录聚合酶链式反应(RT—PCR)得到hGDF-5完整成熟肽基因。将所得基因片段插入克隆载体pMD18-T并转化大肠杆菌DH5α，提取重组质粒，酶切鉴定并测序。结果：DNA琼脂糖凝胶电泳显示：PCR产物为一长约380bp的带，阳性克隆质粒经双酶切可切出约380bp的片段。全自动DNA测序表明与Genbank中的序列完全相符。结论：通过反转录聚合酶链式反应从人胎儿软骨组织中成功克隆出人GDF-5完整成熟肽基因，基因序列完全正确。     

椎间盘退变过程中MMP/Timp基因表达变化的研究

目的:采用新西兰大白兔的纤维环损伤制作腰椎间盘退变模型,以证实和比较在人椎间盘退变中的基因变化情况.方法:损伤L4.5、L5.6纤维环,行核磁共振及计算机扫描摄影拍片证实椎间盘退变情况,同时取椎间盘行精确定量逆转录聚合酶链式反应观测MMP/Timp系列基因的变化.结果:证实了兔腰椎纤维环损伤后腰椎逐渐退变,且与人类退变结果相似,基因表达情况MMP-1、MMP-2、MMP-3、Timp-1、Timp-2早期均上调,MMP-3、Timp-1在退变的晚期出现下调.结论:人类腰椎间盘退变中明显上调的基因在此退变模型椎间盘中被发现同样上调,从而在分子水平证实了此动物退变模型与人类的相似性.     

Role of growth differentiation factor-5 and bone morphogenetic protein type II receptor in the development of lumbar intervertebral disc degeneration

The present study was designed to evaluate the role of growth differentiation factor-5 (GDF-5) and bone morphogenetic protein type II receptor (BMPR-II) in the development of lumbar intervertebral disc degeneration (IDD). A total of 24 patients with lumbar IDD (experiment group) and 6 patients with lumbar vertebral fracture (control group) were enrolled in the study. Tissue samples of IVD from the experiment group and control group were obtained during lumbar fusion operation, respectively. Fixation and decalcification of IVD tissue were performed, and then HE staining was carried out to observe the morphological changes of the lumbar IVD tissues. The expression of GDF-5 and BMPRII in human lumbar IVD was detected by immunohistochemical staining. HE staining results showed that non- and minimal degeneration was found in 11 cases (score range, 0-3), moderate degeneration in 12 cases (score range, 4-8), and severe degeneration in 7 cases (score range, 9-12). According to the immunohistochemical results, the positive expression rates of GDF-5 and BMPRII in NP were higher than those in AF of the non- and minimal degeneration group, moderate degeneration group and severe degeneration group (all P < 0.05). However, no significant difference in GDF-5 or BMPRII positive expression was observed among the normal, non- and minimal, moderate and severe degeneration groups in neither NP area nor AF area (all P > 0.05). In conclusion, our results showed that GDF-5 and BMPRII expressed both in normal and degenerated IVD tissues, and GDF-5 might have an inhibition effect on degenerated lumbar IVD, suggesting that gene therapy may be a useful approach in producing physiological effects during early- and late-phase of lumbar IDD.     

The effect of a bioactive collagen membrane releasing PDGF or GDF-5 on bone regeneration

Regenerative procedures using barrier membrane technology are presently well established in periodontal/endodontic surgery. The objective of this study was to compare the subsequent effects of the released platelet-derived growth factor (PDGF) and growth/differentiation factor 5 (GDF-5) from collagen membranes (CMs) on bone regeneration in vitro and in vivo. In vitro studies were conducted using MC3T3-E1 mouse preosteoblasts cultured with or without factors. Cell viability, cell proliferation, alkaline phosphatase (ALP) activity and bone marker gene expression were then measured. In vivo studies were conducted by placing CMs with low or high dose PDGF or GDF-5 in rat mandibular defects. At 4 weeks after surgery new bone formation was measured using μCT and histological analysis. The results of in vitro studies showed that CM/GDF-5 significantly increased ALP and cell proliferation activities without cytotoxicity in MC3T3-E1 cells when compared to CM/PDGF or CM alone. Gene expression analysis revealed that Runx2 and Osteocalcin were significantly increased in CM/GDF-5 compared to CM/PDGF or control. Quantitative and qualitative μCT and histological analysis for new bone formation revealed that although CM/PDGF significantly enhanced bone regeneration compared to CM alone or control, CM/GDF-5 significantly accelerated bone regeneration to an even greater extent than CM/PDGF. The results also showed that GDF-5 induced new bone formation in a dose-dependent manner. These results suggest that this strategy, using a CM carrying GDF-5, might lead to an improvement in the current clinical treatment of bone defects for periodontal and implant therapy.     

The interaction between aggrecan gene VNTR polymorphism and cigarette smoking in predicting incident symptomatic intervertebral disc degeneration

An association between the aggrecan variable number of tandem repeat (VNTR) polymorphism and the disc degeneration has been previously reported in Finnish men, and smoking had previously been suspected of causing disc degeneration. However, the interaction between aggrecan gene VNTR polymorphism and smoking in symptomatic intervertebral disc degeneration (IDD) has not been well studied. To examine the interaction between aggrecan gene VNTR and smoking in the susceptibility of symptomatic IDD of Chinese Han in northern China, intervertebral discs of 132 participants were evaluated on magnetic resonance imaging, using decreased signal intensity. After harvesting the blood samples, the aggrecan gene VNTR region was analyzed using polymerase chain reaction (PCR). The data indicated that between the two groups, participants carrying one or two alleles ≤25 repeats who did not smoke showed a 1.102-fold increased risk for symptomatic IDD (p= 0.855; 95% confidence interval 0.389–3.119), and participants carrying two alleles >25 repeats who smoked more than 1 pack-year showed a 1.013-fold higher risk (p = 0.982; 95% confidence interval 0.333–3.084), whereas participants carrying one or two alleles ≤25 repeats who smoked more than 1 pack-year showed a 4.5-fold increased risk for symptomatic IDD (p = 0.005; 95% confidence interval 1.589–12.743). Overall, we observed an underlying additive and multiplicative interaction between the aggrecan gene VNTR polymorphism and smoking in symptomatic IDD.     

A preliminary in vitro study into the use of IL-1Ra gene therapy for the inhibition of intervertebral disc degeneration

Conventional therapies for low back pain (LBP) are purely symptomatic and do not target the cause of LBP, which in approximately 40% of cases is caused by degeneration of the intervertebral disc (DIVD). Targeting therapies to inhibit the process of degeneration would be a potentially valuable treatment for LBP. There is increasing evidence for a role for IL-1 in DIVD. A natural inhibitor of IL-1 exists, IL-1Ra, which would be an ideal molecular target for inhibiting IL-1-mediated effects involved in DIVD and LBP. In this study, the feasibility of ex vivo gene transfer of IL-1Ra to the IVD was investigated. Monolayer and alginate cultures of normal and degenerate human intervertebral disc (IVD) cells were infected with an adenoviral vector carrying the IL-1Ra gene (Ad-IL-1Ra) and protein production measured using an enzyme-linked immunosorbent assay. The ability of these infected cells to inhibit the effects of IL-1 was also investigated. In addition, normal and degenerate IVD cells infected with Ad-IL-1Ra were injected into degenerate disc tissue explants and IL-1Ra production in these discs was assessed. This demonstrated that both nucleus pulposus and annulus fibrosus cells infected with Ad-IL-1Ra produced elevated levels of IL-1Ra for prolonged time periods, and these infected cells were resistant to IL-1. When the infected cells were injected into disc explants, IL-1Ra protein expression was increased which was maintained for 2 weeks of investigation. This in vitro study has shown that the use of ex vivo gene transfer to degenerate disc tissue is a feasible therapy for the inhibition of IL-1-mediated events during disc degeneration.     

贵州地区汉族人群GDF5基因单核苷酸多态性与成人终身高的关系

目的 探讨生长分化因子5(GDF5)基因rs143383、rs143384、rs6060369和rs224331位点单核苷酸多态性(SNPs)与贵州地区汉族人群成人终身高的相关性.方法 对贵州地区1 069例汉族健康体检者进行体格检查及问卷调查,收集抗凝血标本并提取DNA.用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)方法检测GDF5基因的SNPs,并分析其与身高的相关性.结果 成年女性中,GDF5基因rs143383、rs143384、rs6060369和rs224331基因型分布可分别解释身高变异的1.4％、0.9％、1.1％和1.0％(P＜0.05);在GDF5基因rs143383和rs143384位点,携带GG基因型的个体平均身高均为最高,分别比AG和AA基因型个体高1.7 cm (P＜0.01)、2.3 cm (P＜0.05)和1.6 cm (P＜0.05)、2.1 cm(P＜0.01);在GDF5基因rs6060369位点,携带CC基因型的个体平均身高分别比CT和TT基因型个体高1.7 cm (P＜0.05)和2.2 cm (P＜0.01).但是在成年男性中未发现GDF5基因上述SNPs位点与身高的相关性.结论 GDF5基因单核苷酸多态性与贵州地区成年汉族女性身高有关,GDF5基因可能是影响中国汉族成人女性身高个体差异的基因.     

碱性成纤维细胞生长因子对兔晶体上皮细胞的增殖作用

观察碱性纤维细胞生长因子（basic fibroblast growth factor,bFGF)对兔晶体上皮细胞（rabbit lens epithelial cells,RLECs)的促增殖作用,以及增殖细胞核抗原（proliferating cell nuclear antigen,PCNA)的表达,用第2－3代培养细胞,用MTT法测定细胞增殖,用免疫组织化学法观察PCNA的表达,流式细胞仪观察细胞周期的变化。结果显示bFGF可促进兔晶体上皮细胞的增殖,尤其是浓度为10μg/L作用最明显;正常细胞组PCNA表达呈阴性,添加bFGF组PCNA表达呈强阳性;并显示进入S期的细胞明显增加,提示bFGF是促进兔晶体上皮细胞增殖的重要因素。