电磁辐射对软骨的生物学效应研究进展

作为半刚性的、无血管和神经的结缔组织,软骨具有承重、应力缓冲和辅助运动等多种生理功能。软骨固有的修复能力差,损伤不易逆转且治疗难度大。近年来,大量研究结果显示适宜的电磁辐射对软骨细胞形态的维持及其细胞因子的分泌、软骨细胞外基质的稳态以及骨关节炎的治疗等都具有积极的意义。笔者就电磁辐射对软骨的生物学效应及其可能的作用机制作一综述。     

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。     

人骨髓基质干细胞体外诱导和鉴定

目的建立人自体骨髓基质干细胞(human menchymal stem cells,hMSCs)体外分离、鉴定体系,建立经诱导表达成骨、软骨、脂肪细胞表型的体外培养体系,探讨作为骨组织工程种子细胞的可能性,为组织工程技术应用打下基础。方法抽取患者骨髓5ml,以密度梯度法分离hMSCs,使用流式细胞仪鉴定细胞表型;应用免疫组化和分子生物学技术,对hMSCs进行成骨、软骨、脂肪细胞的诱导培养和表型鉴定。结果第2代hMSCs阳性细胞表达率CD105(78±6)%,CD166(43±7)%,CD29(69±12)%;hMSCs成骨诱导培养第3代平均扩增(163.4±13.4)倍,形成钙结节,骨细胞转录因子、骨钙素、骨桥蛋白和I型胶原免疫荧光阳性,RT-PCR证实有I型胶原、骨钙素、骨桥蛋白和骨结合素mRNA表达,对照组阴性;成软骨细胞诱导培养后II型胶原、SOX9(SRY-type HMGbox9,是在哺乳动物性别决定和软骨生成中起着关键调控作用的一个基因)。免疫荧光阳性,RT-PCR证实II型胶原、软骨聚集蛋白聚糖mRNA表达,对照组阴性;成脂肪细胞诱导培养后,油红-O染色阳性,RT-PCR证实PPAR2 mRNA...     

Reimplantation of growth plate chondrocytes into growth plate defects in sheep

Defects in growth plates due to trauma, infection, or genetic causes can result in bone formation across the defect, bridging the epiphysis and metaphysis, resulting in growth arrest and limb deformation. We have investigated the capacity of implanted chondrocyte cultures to prevent this process. Sheep growth plate chondrocytes were isolated, and after culture at high density produced easily manipulated cartilaginous discs. The tissue was implanted into growth plate defects produced in lambs and the response was assessed histologically. Following implantation, cultures continued to proliferate and maintain a cartilage-like matrix. After 8 to 12 weeks, hypertrophic maturation chondrocyte columnation, and associated endochondral calcification were observed. Culture implantation was always associated with local immune inflammatory reaction, which continued throughout the course of investigation. Cellular survival was variable and resulted in the presence of viable implants as well as residual cartilage matrix devoid of chondrocytes; however, implanted chondrocyte discs always prevented bone bridge formation. These findings encourage the expectation that cultured chondrocytes may provide a useful replacement for the inert interpositional materials currently used in the treatment of growth arrest. The potential of this technique for growth plate replacement, however, requires a more predictable rate of implant survival. The likely reasons for implant loss are discussed.     

大鼠椎间盘软骨细胞中Bax、Bcl-2及 Caspase-8的表达

目的:探讨椎间盘软骨细胞在正常与凋亡状态下,Bax、Bcl-2及Caspase-8的表达变化情况。方法:使用酶消化法获取雄性SD大鼠椎间盘软骨细胞,抗Fas抗体诱导凋亡,免疫组化法(SP)检测大鼠正常与凋亡椎间盘软骨细胞的Bax、Bcl-2及Caspase-8的表达,CMIAS-99B型医学图像系统进行表达强度的分析,进而比较分析大鼠正常与凋亡椎间盘软骨细胞的Bax、Bcl-2及Caspase-8的表达变化情况。结果:正常组的Bax和Caspase-8轻度表达,凋亡模型组的Bax和Caspase-8表达明显;而正常组的Bcl-2高度表达,凋亡模型组的Bcl-2轻度表达,正常和凋亡各组均有非常显著差异(P<0.01)。结论:凋亡的大鼠椎间盘软骨细胞内Bax、Bcl-2、Caspase-8的表达与正常状态相比有明显变化。     

转化生长因子β1和同种异体软骨细胞及高孔隙率聚乳酸复合物修复兔耳廓软骨缺损

目的　观察加入转化生长因子 β1(transforminggrowthfactor beta 1,TGF β1)的同种异体软骨细胞 /高孔隙率聚乳酸 (poly DL lactide,PDLLA)支架复合物修复兔耳廓软骨缺损的效果。 方法18只大白兔随机分为同种异体软骨细胞 /PDLLA复合物加TGF β1组 (复合物组 )、同种异体软骨细胞 /PDLLA复合物组 (复合物对照组 )和不用任何修复材料的空白对照组 ,每组 6只。分别于 4、12、18周取材 ,行HE和甲苯胺蓝染色 ,观察各组兔耳廓软骨缺损修复情况。结果　术后 18周 ,TGF β1复合物组修复软骨缺损的效果无论从大体标本观察或是病理组织学检查都比复合物对照组的修复效果好 ,空白对照组为纤维组织修复。结论　同种异体软骨细胞 /PDLLA复合物移植可形成组织工程化软骨修复兔耳廓软骨缺损 ,TGF β1可提高同种异体软骨细胞 /PDLLA复合物移植修复兔耳廓软骨缺损的质量。     

Cytosolic calcium concentration in bovine growth plate chondrocytes

The cytosolic free calcium ion concentration for mammalian cell systems is believed to be maintained within a narrow range compatible with cellular homeostasis. Growth plate chondrocytes have been shown to accumulate large quantities of calcium within their mitochondria, but the cytosolic free calcium concentration has not been determined. This study measures the cytosolic free ionic calcium concentration in growth plate chondrocytes using two variations of the Quin II fluorescence technique. The results indicate that in isolated growth plate chondrocytes, the cytosolic free ionic calcium concentration is similar to other nonmineralizing mammalian cell types (106–137 nM).     

人关节软骨细胞的永生化及其表型的诱导

目的 用基因转染技术使人关节软骨细胞（HACs)向永生化转化，通过诱导使永生化软骨细胞的表型得到维持。方法 利用编码人类乳头瘤病毒16型E7基因片段（HPV16E7）的逆转录病毒表达载体pLXSN转染HACs，挑取转化细胞克隆并扩大增殖，继用核型分析，克隆形成实验，裸鼠致瘤实验检测转化特性，Nutridoma-sp及抗坏血酸盐无血清诱导培养基诱导并维持转化软骨细胞的Ⅱ型胶原表型。结果 HACs被HPV16E7成功转化，目前传代已达50代，转化的HACs为良性转化，诱导培养基能够使转化软骨细胞的Ⅱ型胶原合成增加并维持在正常水平。结论 HPV16E7能够使HACs良性转化并长期培养经诱导后转化软骨细胞的Ⅱ型胶原表型能够得到很好维持。     

Modulation of cartilage's response to injury: Can chondrocyte apoptosis be reversed?

Osteoarthritis is characterized by a chronic, progressive and irreversible degradation of the articular cartilage associated with joint inflammation and a reparative bone response. More than 100 million people are affected by this condition worldwide with significant health and welfare costs. Our available treatment options in osteoarthritis are extremely limited. Chondral or osteochondral grafts have shown some promising results but joint replacement surgery is by far the most common therapeutic approach. The difficulty lies on the limited regeneration capacity of the articular cartilage, poor blood supply and the paucity of resident progenitor stem cells. In addition, our poor understanding of the molecular signalling pathways involved in the senescence and apoptosis of chondrocytes is a major factor restricting further progress in the area. This review focuses on molecules and approaches that can be implemented to delay or even rescue chondrocyte apoptosis. Ways of modulating the physiologic response to trauma preventing chondrocyte death are proposed. The use of several cytokines, growth factors and advances made in altering several of the degenerative genetic pathways involved in chondrocyte apoptosis and degradation are also presented. The suggested approaches can help clinicians to improve cartilage tissue regeneration.