兔骨髓间充质干细胞定向诱导移植修复关节软骨的实验研究

目的：通过诱导兔骨髓间充质干细胞（MSCs），观察干细胞向软骨细胞的分化效果。方法：纯化兔骨髓间充质干细胞；用含转化生长因子β1的诱导液培养骨髓间充质干细胞；以MTT测定诱导细胞的增殖活性；免疫组化检测Ⅱ型胶原蛋白的表达；诱导后的细胞移植于白兔膝关节内，X线摄片观察软骨修复形成情况。结果：诱导液可有效诱导MSCs向软骨细胞表型转化，且骨髓间充质干细胞向软骨细胞分化所需的特异性细胞外基质——Ⅱ型胶原明显升高，移植后效果明显。结论：兔骨髓间充质干细胞定向诱导后移植修复关节软骨是有效的。因此骨髓间充质干细胞有可能成为软骨组织工程较理想的种子细胞来源。     

不同类型人软骨细胞体外生物学特性比较

目的　通过研究人耳软骨和肋软骨两种不同类型软骨细胞体外分离、增殖、老化规律 ,为选择合适的组织工程种子细胞提供依据。方法　取小耳畸形残耳软骨和肋软骨 ,体外分别用0 .0 5 %和 0 .15 %Ⅱ型胶原酶消化 16h分离 ,台盼蓝染色计活细胞数 ,得原代细胞获得率。体外单层培养 6代 ,观察形态学改变 ,群体倍增时间 (PDT ) ,免疫细胞化学染色及逆转录 聚合酶链反应(RT PCR)检测Ⅱ型胶原和Aggrecan评定软骨细胞老化规律。 结果　人残耳软骨组织平均细胞获得率为 ( 1.5 4± 0 .14 )× 10 6/ g ,肋软骨平均获得率为 ( 0 .46± 0 .0 9)× 10 6/ g ,两类软骨细胞P1的PDT最短 ,前 3代增殖力较强 ,P3 以后PDT明显延长 ,P6代细胞不再增殖。免疫细胞化学及RT PCR均证实耳软骨细胞 3代内、肋软骨细胞 4代内软骨细胞表型稳定。结论　第 2代的耳软骨细胞与第 3代肋软骨细胞可作为人体内组织工程化软骨构建的种子细胞。     

Prologation of c-Jun N-terminal kinase is associated with cell death induced by tumor necrosis factor alpha in human chondrocytes

The aim of this study was to elucidate the role of JNK signaling pathway involved in tumor necrosis factor-alpha (TNF-alpha)-induced death of chondrocytes. Primary chondrocyte cultures were obtained from human knee osteoarthritis cartilages. First passage chondrocytes were treated with TNF-alpha and various potentiators, and cell death was measured with MTT assay. C-Jun N terminal kinase (JNK) activation was investigated with the solid phase kinase assay. Expression of apoptosis-related molecule was assayed with Western blot. Chondrocytes were resistant to TNF-alpha-induced cell death. In contrast, pretreatment with actinomycin D, the phosphatase inhibitor vanadate or MAP kinase phosphatase-1 (MKP-1) inhibitor Ro318220 invariably led to chondrocyte death. While TNF-alpha alone stimulated a single, brief JNK activity, a second JNK peak was observed when the cells were pretreated with actinomycin D. When the cells were pretreated with vanadate or Ro318220, TNF-alpha-induced JNK activation was greatly prolonged, which was associated with the induction of cell death. The expression of Bcl-2 and Mcl-1 decreased significantly in conditions of cell death. In conclusions, our data suggest that chondrocyte death induced by TNF-alpha is associated with sustained JNK activation. This effect may be due to downregulation of TNF-alpha induced phosphatase that inactivates JNK and of Bcl-2 family proteins.     

软骨形态发生蛋白1诱导真皮成纤维细胞表达软骨细胞表型的实验研究

目的应用软骨形态发生蛋白(CDMP)生长因子,体外诱导真皮成纤维细胞向成软骨细胞表型分化,探讨其作为组织工程化软骨种子细胞的可行性.方法取包皮环切术后丢弃真皮组织共3例,成纤维细胞体外培养扩增至第二代,以1×104/cm2密度接种,12 h后加入细胞诱导液(10%胎牛血清F-12培养液,CDMP1终浓度为100 ng/ml)单层培养,未加的成纤维细胞培养用CDMP1为对照.诱导7 d后观察细胞形态变化,Image Plus图像分析软件计算细胞长宽比例.激光共聚焦显微镜分别观察诱导前后细胞内Ⅰ、Ⅱ、Ⅲ型胶原表达及分布,Western印迹检测诱导前后细胞Ⅱ型胶原蛋白表达.反转录聚合酶链式反应(RT-PCR)检测诱导后成软骨相关的Sox9、聚集蛋白聚糖与Ⅱ、Ⅸ型胶原mRNA表达;同时检测与成骨相关的X型胶原、碱性磷酸酶(AKP)mRNA表达.培养第二代细胞以2×107个细胞/ml细胞密度进行离心管法培养,诱导14 d后行阿辛蓝与Ⅱ型胶原免疫组化染色.结果诱导后可见单层培养的成纤维细胞形态由长梭形向软骨细胞样多角形转变,Image Plus图像分析软件计算细胞诱导后的长宽比例为(1.40±0.15),较诱导前(7.40±1.30)差异有显著意义(P＜0.05);与正常软骨细胞(1.29±0.24)差异无显著意义.免疫荧光激光共聚焦观察发现诱导后细胞内出现Ⅱ型胶原表达,Ⅰ、Ⅲ型胶原表达呈阳性.RT-PCR检测成软骨相关的Sox9,聚集蛋白聚糖,Ⅱ、Ⅸ型胶原mRNA表达阳性;X型胶原、AKP未检测到mRNA阳性表达.Western印迹检测细胞诱导后Ⅱ型胶原蛋白表达阳性.离心管培养诱导7 d后阿辛蓝染色示糖胺聚糖(GAG)均匀分布于基质中,免疫组化染色示基质中Ⅱ型胶原表达阳性.结论第二代成人真皮成纤维细胞在CDMP1生长因子诱导下可向成软骨细胞表型分化,并能分泌软骨细胞特异性基质,有望成为软骨组织工程新的种子细胞来源.     

兔软骨细胞在可注射温敏型壳聚糖/聚乙烯醇凝胶中生长的研究

目的 探讨以壳聚糖(CS)和聚乙烯醇(PVA)制备的可注射温敏型凝胶作为兔软骨细胞生长支架的可行性.方法 将壳聚糖和聚乙烯醇溶液混合制成温敏型凝胶,取第三代软骨细胞接种于凝胶支架,于接种后24、48和72 h采用MTT测定细胞活性及毒力;于1、2及3周后采用扫描电镜及共聚焦激光扫描荧光显微镜观察软骨细胞在凝胶中的形态及生长状态.结果 MTT结果显示接种细胞数量随着接种细胞生长时间的推移而明显增加,各组之间差异有统计学意义(P＜0.05).扫描电镜及激光共聚焦荧光显微镜观察表明软骨细胞在CS/PVA凝胶支架中生长良好.软骨细胞在凝胶支架中保持了很高的增殖能力,材料对细胞无明显不良反应.结论 壳聚糖/聚乙烯醇混合凝胶可作为兔软骨细胞培养的生长支架,应用于软骨组织工程.     

关节软骨细胞分离和培养及其在中医药研究中的应用进展

综述关节软骨细胞的分离和培养研究进展,并阐述其在中医药研究中的意义。     

1,25(OH)2D3 receptor regulation and 1,25(OH)2D3 effects in primary cultures of growth cartilage cells of the rat

Summary Vitamin D deficiency leads to disturbed calcification of growth cartilage and enlargement of growth plate, illustrating that chondrocytes are a target for vitamin D. This observation prompted an investigation of 1,25(OH)₂D₃ receptor expression and action of vitamin D metabolites on chondrocyte proliferation. In primary cultures of tibial growth cartilage of male SD rats (80 g), specific binding of [³H]-1,25(OH)₂D₃ is noted in both the logarithmic growth phase and at confluence (N_max 12780 molecules/cell versus 4368 molecules/cell). Scatchard analysis revealed the presence of a single class of noninteracting binding sites. K_D was 10⁻¹¹ M irrespective of growth phase. The binding macromolecule had a sedimentation coefficient of 3.5 S. Interaction with DNA was demonstrated by DNA cellulose affinity chromatography. In immunohistology, growth cartilage cells (rabbit tibia) expressed nuclear 1,25(OH)₂D₃ receptors most prominently in the proliferative and hypertrophic zone. This corresponds to binding data which showed highest N_max in the proliferating cartilage. 1,25(OH)₂D₃ in the presence of delipidated fetal calf serum (FCS) had a biphasic effect on cell proliferation and density, i.e., stimulation at 10⁻¹² M and dose-dependent inhibition at 10⁻¹⁰ M and below. Inhibition was specific and not seen with 24,25(OH)₂D₃ or dexamethasone. Growth phase-dependent 1,25(OH)₂D₃ receptor expression and effects of 1,25(OH)₂D₃ on chondrocyte proliferation point to a role of vitamin D in the homeostasis of growth cartilage.     

骨关节炎中软骨细胞的CD80/CD86的表达及白细胞介素18对其影响

目的探讨软骨细胞及γ-干扰素(γ-IFN)在骨关节炎发病中的作用。方法收集10例膝关节骨关节炎患者软骨标本为病例组,同时收集8例股骨颈骨折患者软骨标本为正常对照组。经过软骨细胞培养及γ-IFN的刺激,采用流式细胞技术检测CD80/CD86的表达情况。结果病例组软骨细胞表达CD80的阳性细胞百分率(2.47%±0.59%)比正常对照组软骨细胞(0.94%±0.25%)高(P<0.01)。病例组软骨细胞表达CD86的阳性细胞百分率(1.71%±0.71%)比正常对照组软骨细胞(0.93%±0.47%)高(P<0.01)。正常对照组软骨细胞在γ-IFN刺激后CD80阳性百分率(7.39%±3.18%)比刺激前明显增高(P<0.01),CD86阳性百分率刺激后(4.96%±3.11%)明显升高(P<0.01)。OA组软骨细胞在γ-IFN刺激后CD80和CD86阳性百分率(7.54%±4.47%、6.52%±4.24%)比刺激前明显增高(P<0.01)。两组软骨细胞在γ-IFN刺激后CD80和CD86的表达差异均没有显著性。结论正常软骨细胞有抗原提呈的潜能,γ-IFN可以诱导正常软骨细胞表达CD80/CD86增加,γ-IFN在骨关节炎发病中可能发挥致炎因子的作用。