人髂骨生长板软骨细胞的体外培养及鉴定

[目的]探讨人髂骨生长板软骨细胞体外培养的可行性并观察其生物学特征。[方法]对手术中获得的10例青少年特发性脊柱侧凸患者髂骨生长板软骨行体外分离、培养，观察细胞形态，MTT法测定细胞增殖，Ⅱ型胶原免疫组化染色，采用逆转录聚合酶链反应检测各代细胞Ⅱ型胶原mRNA的表达水平。[结果]（1）体外培养的软骨细胞随着传代次数的增加，细胞形态由原代的多角形逐渐变为长梭形；（2）MTT比色法检测显示，第2代髂软骨细胞的生长曲线近似倒“S”形，在第4～8d细胞呈对数生长，在9～10d达平台期，至第11d开始出现生长抑制。（3）第2代细胞Ⅱ型胶原免疫组化呈强阳性。（4）Ⅱ型胶原mRNA表达水平从第2代后随着传代次数的增加逐渐下降。[结论]采用联合酶序贯消化法将软骨细胞悬液和软骨块共同体外培养髂软骨细胞简单、有效，P2代细胞很好的保持了软骨细胞的特性，可以作为种子细胞来源。     

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。     

Cathepsin K基因抑制后对软骨细胞功能的影响研究

目的研究应用RNA干扰技术早期抑制人CathepsinK（CTSK）基因的表达对延缓软骨细胞的去分化过程及维持软骨细胞表型的影响。方法pGCsilencer TMH1／Nco／GFP／CTsKRNAi质粒体外转染人软骨细胞,并用G418筛选3周．再通过RT—PCR检测CTSK、Ⅱ型胶原和AggrecancDNA转录的表达,Western-Blot、免疫荧光检测转染后软骨细胞的CTSK、Ⅱ型胶原和Aggrecan在蛋白水平的表达。结果装入质粒载体转染第1代的软骨细胞,在体外通过细胞形态观察可发现,抑制CTSK基因后3周软骨细胞仍大多数保持多角形,而对照组则向成纤维样细胞形态变化。RT—PCR结果显示,在mRNA水平抑制了CTSK的表达,而不影响对软骨细胞Ⅱ型胶原和Aggrecan的mRNA表达。免疫荧光和Wesfem—blot的结果证实了在早期抑制了软骨细胞CTSK基因表达并维持3周左右。软骨细胞的特异性基质Ⅱ型胶原和Aggrecan在蛋白水平明显增加。结论早期抑制了软骨细胞CTSK基因的表达,可使软骨细胞去分化过程中其软骨特异性基质Ⅱ型胶原和Aggrecan增加,说明可以维持软骨细胞的表型。     

软骨细胞老化过程中胞外基质表达水平的改变

目的研究猪耳软骨细胞在体外培养传代过程中,细胞老化相关基因和胞外基质相关基因表达水平的改变。方法取体外培养猪耳软骨细胞,通过光镜,对各代细胞的形态学变化进行观测。RT-PCR检测各代细胞中bcl-2、端粒酶、Ⅰ型胶原和Ⅱ型胶原在mRNA表达水平上的改变。结果体外培养软骨细胞随着老化的进程,逐渐显现衰老和凋亡的特征。凋亡抑制基因bcl-2和控制细胞分裂的端粒酶的表达显著下降(P<0.01)。软骨细胞的特征性基质分子Ⅱ型胶原在第3代时表达水平有显著下降(P<0.01),降至原代细胞的5.47%±1.04%,在第4代几乎不再表达。而Ⅰ型胶原在第5代时,有显著上升(P<0.01);在第9代时又显著下降(P<0.01)。结论猪软骨细胞经体外培养,由第4代起逐渐发生去分化,丧失软骨细胞的表型。同时,细胞的增殖分裂能力亦逐步减退,细胞凋亡现象明显增加。     

先天性小耳畸形残耳软骨细胞的体外生物学行为的实验研究

目的 探讨先天性小耳畸形残耳软骨细胞体外生长的生物学特性.方法 取先天性小耳畸形患者外耳再造手术中废弃的残耳软骨组织,采用胶原酶消化法获得残耳软骨细胞;体外传代培养及生物学特性研究:细胞形态学观察,细胞生长曲线测定,Ⅱ型胶原免疫组化鉴定残耳软骨细胞.RT-PCR检测第1～5代残耳软骨细胞的Ⅱ型胶原及蛋白多糖的mRNA表达.结果 原代和第1～3代残耳软骨细胞生长旺盛,呈多角形,第3代以后细胞体积变大,呈长梭形转化,细胞增殖逐渐减弱;免疫组化检测第2代残耳软骨细胞Ⅱ型胶原表达呈阳性;RT-PCR显示mRNA水平第1～3代软骨细胞Ⅱ型胶原高表达,随传代次数增加表达逐渐减弱,第5代基本消失;第1～3代细胞蛋白多糖呈高表达,第4代以后随传代表达逐渐减弱.结论 体外成功分离培养出残耳软骨细胞,第1～3代细胞形态保持稳定,Ⅱ型胶原和蛋白聚糖稳定呈高表达.     

大鼠肋软骨细胞体外培养及老化对基质代谢的影响

目的建立大鼠肋软骨细胞(RCC)分离、培养的方法,探讨其老化过程中细胞外基质及其相关基因的变化,为软骨细胞增殖分化的调控和软骨组织工程修复的研究建立实验基础。方法显微解剖出大鼠软骨,酶消化法获得分散的单个RCC。观察单层培养的不同代数RCC的细胞形态变化;采用免疫细胞化学方法检测不同代数RCC蛋白多糖和Ⅱ型胶原的表达;RT-PCR从mRNA水平分析Ⅱ型胶原、蛋白聚糖及蛋白聚糖酶-1、2(Aggrecanse-1,2)基因表达量。结果本实验分离的RCC呈多角形或圆形,第4代细胞形态发生变化;第1代到第3代细胞蛋白聚糖逐渐减少,第4代明显下降;Ⅱ型胶原(Collagen)含量随着细胞的老化逐渐减少;Aggrecanse-1前3代无明显变化,第4代明显上升,而Aggrecanse-2则无明显改变。结论本研究所建立的分离培养方法可以获得高纯度、高活性的软骨细胞,前3代RCC保持了在体软骨细胞的表型,是研究软骨细胞生物活性的良好材料。     

人脂肪来源的成体干细胞体外向软骨细胞诱导分化的研究

目的研究人脂肪来源的成体干细胞（ADSC）体外能否向软骨细胞成功分化，探讨其作为组织工程软骨种子细胞的可行性。方法自成人皮下取少量脂肪组织，经机械剪切及Ⅰ型胶原酶消化后获取成体干细胞，体外培养扩增；流式细胞仪鉴定细胞表型；第5代细胞采取离心管中微块法培养，培养液中加入转化生长因子（hTGF-β2）等诱导剂诱导其向软骨细胞分化；诱导14d的细胞团经消化后获得单细胞悬液，接种于玻片上行形态学观察，甲苯胺兰、免疫组织化学染色及逆转录-聚合酶链式反应（RT—PCR）用以鉴定软骨细胞表型。结果从人体皮下脂肪组织中可成功分离到ADSC，细胞可于体外大量扩增；第5代细胞大多数表达CD29、CD90，而CD14、CD45抗原表达阴性；RT—PCR结果提示诱导后的细胞可表达黏多糖（GAG）及Ⅱ型胶原，诱导后的细胞块分离成单个细胞后可见其形态较诱导前发生明显变化，甲苯胺兰染色和Ⅱ型胶原免疫组织化学染色为阳性。对照组未加诱导因子的细胞则未能观察到上述变化。结论成人皮下脂肪组织中可分离到大量ADSC；ADSC可在体外成功诱导向软骨细胞分化；ADSC有望作为组织工程软骨构建中的种子细胞。     

残耳软骨细胞诱导脂肪来源干细胞体外软骨形成实验研究

目的探讨残耳软骨细胞能否在体外模拟软骨诱导微环境,促进脂肪来源干细胞(adipose derived stemcells,ADSCs)向软骨分化并形成软骨样组织。方法取外耳再造术中废弃的先天性小耳畸形患者残耳软骨组织与皮下脂肪组织分离培养,分别收集第2代残耳软骨细胞与第3代ADSCs,以3∶7比例混合培养作为实验组(A组),单纯残耳软骨细胞和单纯ADSCs作为对照(分别为B组和C组)。取各组细胞1.0×106个离心培养获得细胞球后,体外培养28 d,大体观察各组细胞球取材时的外观变化,测量湿重;阿利辛蓝比色法检测糖胺多糖(glycosaminoglycan,GAG)含量;RT-PCR检测各组标本的Ⅱ型胶原、蛋白聚糖(Aggrecan)mRNA表达;并行HE、甲苯胺蓝、番红O组织学观察及Ⅱ型胶原免疫组织化学检测。结果体外培养28 d后,A、B组标本形成白色半透明圆盘状组织块,表面光滑,弹性可;C组标本组织块有明显收缩,呈黄色球状,无弹性。A、B组标本湿重及GAG含量显著高于C组(P<0.05);A、B组间差异无统计学意义(t=1.820 3,P=0.068 7;t=1.861 4,P=0.062 7)。RT-PCR检测示A、B组标本均可见Ⅱ型胶原与Aggrecan mRNA条带清晰表达,C组未见明显表达;A、B组Ⅱ型胶原与Aggrecan mRNA表达均显著高于C组(P<0.05),A、B组间差异无统计学意义(t=1.457 6,P=0.144 9;t=1.519 5,P=0.128 6)。组织学观察示:A组与B组细胞球标本形成了大量软骨陷窝样结构,细胞外基质均有不同程度染色;C组细胞球标本组织内主要为纤维性成分,未见软骨陷窝,细胞外基质染色阴性。A、B组可见在软骨陷窝周围有不同程度棕黄色沉淀即Ⅱ型胶原表达,C组未见明显表达;A、B组灰度值显著低于C组(P<0.01),A、B组间差异无统计学意义(t=1.661 5,P=0.097 0)。结论残耳软骨细胞可在体外独立模拟软骨诱导微环境,促进ADSCs软骨定向分化并形成软骨组织。     

Characterisation of human knee meniscus cell phenotype

OBJECTIVE: Studies on the biology of the human meniscus cell are scarce. The objective of our studies was to assess survival/proliferation of human meniscus cells in different culture conditions and to characterize the extracellular matrix (ECM) produced by these cells in these artificial environments. The composition of this ECM offers a variable to define the distinct meniscus cell phenotype. MATERIALS AND METHODS: Human meniscus cells were isolated enzymatically from visually intact lateral and medial knee menisci. Cells were cultured in monolayer conditions or in alginate gel. The composition of the cell-associated matrix (CAM) accumulated by the isolated cells during culture was investigated and compared to the CAM of articular chondrocytes cultured in alginate using flow cytometry with fluorescein isothiocyanate-conjugated monoclonal antibodies against type I collagen, type II collagen and aggrecan. Additional cell membrane markers analysis was performed to further identify the different meniscus cell populations in the alginate culture conditions and meniscus tissue sections. Proliferation was analyzed using the Hoechst 33258 dye method. In some experiments, the effect of TGFbeta1 on some of these variables was investigated. RESULTS: The CAM of monolayer cultured meniscus cells is composed of high amounts of type I and II collagen and low amounts of aggrecan. A major population of alginate cultured meniscus cells on the other hand synthesized a CAM containing high amounts of type I collagen, low amounts of type II collagen and high amounts of aggrecan. This population is CD44+CD105+CD34-CD31-. In contrast, a minor cell population in the alginate culture did not accumulate ECM and was mainly CD34+. The CAM of alginate cultured articular chondrocytes is composed of low amounts of type I collagen, high amounts of type II collagen and aggrecan. The expression of aggrecan and of type II collagen was increased by the addition of TGFbeta1 to the culture medium. The proliferation of meniscus cells is increased in the monolayer culture conditions. Cell numbers decrease slightly in the alginate culture, but can be increased after the addition of TGFbeta1. CONCLUSION: These results demonstrate that the human meniscus is populated by different cell types which can be identified by a distinct CAM composition and membrane marker expression. Unlike the monolayer culture conditions, the alginate culture conditions appear to favor a more fibrochondrocyte-like cell accumulating a CAM resembling the native tissue composition. This CAM composition is distinctly different from the CAM composition of phenotypically stable articular cartilage chondrocytes cultured in the same alginate matrix.     

三步酶消化法高效分离兔原代关节软骨细胞及体外培养观察

目的　观察设计的三步酶消化法分离原代关节软骨细胞的效果,并对体外培养不同代次细胞的生物学活性进行评价。方法　三步酶消化法设计为以培养液配制的1g/L胰蛋白酶及1g/LEDTA混合液、1g/L透明质酸酶和2g/LⅠ型胶原酶顺序消化关节软骨分离细胞,检测细胞收获效率和存活率;体外传代培养观察细胞形态、生长及胞外基质中Ⅰ型和Ⅱ型胶原、蛋白多糖聚集体等的变化。结果　(1)关节软骨经三步酶消化基质逐步解离和降解,细胞得以完全释放和分离,每克软骨的细胞收获量平均为50 3×106 个细胞,细胞存活率平均为98. 8%。(2)原代和第一代细胞附壁生长呈三角形或多角形,生长融合时呈卵圆形,Ⅱ型胶原免疫组化和甲苯胺蓝异染反应均呈阳性,原代细胞外基质有高的硫酸糖胺多糖含量为(92±10)μg/cm2;第三代后细胞逐渐变为梭形,Ⅱ型胶原免疫组化为阴性,甲苯胺蓝异染反应明显减弱,第四代细胞外基质的硫酸糖胺多糖含量为(48±12)μg/cm2。结论　(1)三步酶消化法可使关节软骨基质完全消化降解,具有高细胞收获率、高细胞存活率和操作简便等特点。(2)原代和第一代软骨细胞具有良好的生物学活性,而第三代以后的细胞生物学活性低下。     

Flow cytometric analysis of the human articular chondrocyte phenotype in vitro

OBJECTIVE: To develop flow cytometry for the study of human articular cartilage cell phenotype and to validate the method on chondrocytes cultured in different in-vitro systems. METHODS: Chondrocyte phenotype was modulated by culturing the cells under different in-vitro conditions: i.e. in monolayer and in suspension culture in gelled agarose. Monolayer cultured chondrocyte phenotype was assayed by immunohistochemical staining with monoclonal antibodies against chondrocyte-specific aggrecan, type II and I collagen. Flow cytometry was used to quantify the proportions of chondrocytes expressing these extracellular matrix molecules in both culture conditions. To exclude the effects of cell-harvesting methods on the presence of cell-bound ECM molecules, non-proteolytic isolation procedures were used to obtain the chondrocytes for flow cytometry. Subconfluent cells from monolayer cultures were detached with EDTA. Chondrocytes cultured in gelled agarose were obtained after the agarose was enzymatically digested with agarase. RESULTS: Immunohistochemical staining showed that monolayer-cultured chondrocytes, in the presence of serum, gradually lost the expression of chondrocyte-specific aggrecan and type II collagen, while type I collagen was increasingly expressed. Flow cytometry allowed monolayer cultured chondrocyte phenotype to be assessed reproducibly. Chondrocyte phenotype was characterized through the cell membrane-associated extracellular matrix antigens. EDTA, used to obtain single cells from monolayer cultures, did not affect the cell-associated matrix. Where the chondrocytes had been cultured in gelled agarose, flow cytometry allowed quantification of the percentages of chondrocytes maintaining or reexpressing their original phenotype. The agarase digestion procedure used to isolate the cells from the agarose gel did not affect the plasma membrane-associated extracellular matrix antigens. CONCLUSION: Flow cytometry allows quantification of cells expressing aggrecan, type II and I collagen in their cell-associated extracellular matrix. A continuously increasing number of specific monoclonal antibodies will broaden the range of applications offered by this method.     

重组腺病毒介导外源性SOX9在正常关节软骨细胞中诱导软骨基质合成的体外表达

背景：关节软骨损害是临床一种常见的损伤,软骨形成转录因子SOX9是一种调控Ⅱ型胶原合成的关键因子。 目的：观察以表达外源性SOX9的腺病毒体外成功感染关节软骨细胞后对Ⅱ型胶原和蛋白聚糖（Aggrecan）合成的影响,探讨软骨损伤后修复软骨缺损的基因治疗方法。 方法：体外构建腺病毒载体AdSOX9和AdGFP,成功感染培养的人关节软骨细胞,分别以逆转录聚合酶链式反应（RT-PCR）技术检测了病毒感染前后SOX9、II型胶原和蛋白聚糖基因mRNA的表达,同时以免疫组化技术检测了病毒感染前后关节软骨细胞中Ⅱ型胶原的表达。 结果：应用AdEasy腺病毒构建专利技术体外成功构建了能高效表达外源性SOX9的腺病毒AdSOX9和只表达绿色荧光蛋白GFP的腺病毒AdGFP;以腺病毒AdSOX9和AdGFP体外成功感染人关节软骨细胞后48h,未感染对照组和AdGFP感染组,均检测到了Ⅱ型胶原和蛋白聚糖的表达;而AdSOX9感染组的细胞中,检测到了SOX9基因mRNA的表达明显增高,与未感染对照组和AdGFP感染组相比有显著性差异（P〈0．05）,同时,Ⅱ型胶原和蛋白聚糖的表达也较未感染对照组和AdGFP感染组明显增高,差异显著（P〈0．05）。 结论：以外源性SOX9为目的基因的腺病毒介导基因治疗方法,在促进关节软骨细胞Ⅱ型胶原和蛋白聚糖合成方面得出了初步满意的结果,SOX9可能是关节软骨缺损基因治疗研究领域一个新的理想靶点,值得继续深入研究。     

Connective tissue growth factor mRNA expression pattern in cartilages is associated with their type I collagen expression

Connective tissue growth factor (CTGF) has been identified as a secretory protein encoded by an immediate early gene and is a member of the CCN family. In vitro CTGF directly regulates the proliferation and differentiation of chondrocytes; however, a previous study showed that it was localized only in the hypertrophic chondrocytes in the costal cartilages of E 18 mouse embryos. We described the expression of CTGF mRNA and protein in chondrocytes of different types of cartilages, including femoral growth plate cartilage, costal cartilage, femoral articular cartilage, mandibular condylar cartilage, and cartilage formed during the healing of mandibular ramus fractures revealed by in situ hybridization and immunohistochemistry. To characterize the CTGF-expressing cells, we also analyzed the distribution of the type I, type II, and type X collagen mRNA expression. Among these different types of cartilages we found distinct patterns of CTGF mRNA and protein expression. Growth plate cartilage and the costal cartilage showed localization of CTGF mRNA and protein in the hypertrophic chondrocytes that expressed type X collagen mRNA with less expression in proliferating chondrocytes that expressed type II collagen mRNA, whereas it was also expressed in the proliferating chondrocytes that expressed type I collagen mRNA in the condylar cartilage, the articular cartilage, and the cartilage appearing during fracture healing. In contrast, the growth plate cartilages or the costal cartilages were negative for type I collagen and showed sparse expression of CTGF mRNA in the proliferating chondrocytes. We found for the first time that CTGF mRNA could be differentially expressed in five different types of cartilage associated with those expressing type I collagen. Moreover, the spatial distribution of CTGF mRNA in the cartilages with type I collagen mRNA suggested its roles in the early differentiation, as well as in the proliferation and the terminal differentiation, of those cartilages.     

Rapid phenotypic changes in passaged articular chondrocyte subpopulations.

Articular chondrocytes are often expanded in vitro and then used to assist in healing articular cartilage defects. We investigated the extent of dedifferentiation in monolayer-passaged, zonal articular chondrocytes by using quantitative, real-time PCR. The relative gene expressions for collagen type I and II, aggrecan, and superficial zone protein were analyzed for relevant passage numbers (P0-P4) to determine how the expansion of chondrocytes affects the expression of cartilage extracellular matrix proteins. Results reveal that dramatic changes occur as early as first passage. Furthermore, these changes are shown to persist even when the expanded cells are encapsulated in 3D, alginate beads. Successful tissue engineering and autologous cell transplantation procedures rely heavily on having a cell source that expresses the chondrocytic phenotype. The results of this study suggest that major problems exist at the front-end of cartilage regeneration efforts.