Plasticity of clonal populations of dedifferentiated adult human articular chondrocytes
Plasticity of clonal populations of dedifferentiated adult human articular chondrocytes
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DOI：
10.1002/art.10950
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发表时间：
2003-05-01
影响因子：
--
通讯作者：
Martin, I
中科院分区：
文献类型：
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作者：
Barbero, A;Ploegert, S;Martin, I
Objective.为了研究单层扩张去分化的成人关节软骨细胞（AHAC）是否可以向不同的间充质谱系分化，如果是这样，这种能力是否受到单层扩张过程中生长因子的调节。AHAC在不含（对照）或含促进细胞去分化的因子（转化生长因子β 1、成纤维细胞生长因子2和血小板衍生生长因子BB型[TFP]）的培养基中扩增为多克隆或克隆群体。然后在促进成软骨、成骨或成脂分化的条件下培养细胞，并通过组织学、生物化学和实时逆转录-聚合酶链反应评估获得的表型。对照和TFP扩增的AHAC的多克隆群体向软骨形成、成骨和脂肪形成谱系分化。与对照扩增的AHACs相比，TFP扩增的细胞显示出增强的软骨分化能力（糖胺聚糖/DNA含量高2.4倍，11型胶原蛋白上调高2,500倍）和成骨分化能力（碱性磷酸酶活性增加9.4倍，骨唾液蛋白上调12.4倍），但减少了脂肪细胞的形成（油红O-阳性细胞/面积低5.2倍）。AHAC的克隆群体可以有效地扩大在TFP，但不是在对照培养基。大多数的TFP扩增克隆仅能再分化成软骨细胞（7/20）或不能分化（6/20）。然而，一些克隆（20个中的2个）向所研究的所有谱系分化，从而显示间充质祖细胞的特征。去分化的AHAC表现出分化可塑性，这是由单层扩增过程中使用的生长因子调节，并且在不同的克隆中是高度异质的。在调节分子存在下的AHAC的克隆培养可以导致鉴定具有增强的软骨修复能力的AHAC亚群。
Objective. To investigate whether adult human articular chondrocytes (AHACs), dedifferentiated by monolayer expansion, can differentiate toward diverse mesenchymal lineages and, if so, whether this ability is regulated by growth factors during monolayer expansion.Methods. AHACs were expanded as multiclonal or clonal populations in medium without (control) or with factors enhancing cell dedifferentiation (transforming growth factor beta1, fibroblast growth factor 2, and platelet-derived growth factor type BB [TFP]). Cells were then cultured under conditions promoting chondrogenic, osteogenic, or adipogenic differentiation, and the acquired phenotypes were assessed histologically, biochemically, and by real-time reverse transcriptase-polymerase chain reaction.Results. Multiclonal populations of both control- and TFP-expanded AHACs differentiated toward the chondrogenic, osteogenic, and adipogenic lineages. Compared with control-expanded AHACs, TFP-expanded cells displayed enhanced chondrogenic differentiation capacity (2.4-fold higher glycosaminoglycan/DNA content and 2,500-fold higher up-regulation of type 11 collagen) and osteogenic differentiation capacity (9.4-fold higher increase in alkaline phosphatase activity and 12.4-fold higher up-regulation of bone sialoprotein), but reduced formation of adipocytes (5.2-fold lower oil red O-positive cells/area). Clonal populations of AHACs could be efficiently expanded in TFP, but not in control medium. Most TFP-expanded clones were able to redifferentiate only into chondrocytes (7 of 20) or were unable to differentiate (6 of 20). However, some clones (2 of 20) differentiated toward all of the lineages investigated, thus displaying characteristics of mesenchymal progenitor cells.Conclusion. Dedifferentiated AHACs exhibit differentiation plasticity, which is modulated by growth factors used during monolayer expansion and is highly heterogeneous across different clones. Clonal culture of AHACs in the presence of regulatory molecules could lead to the identification of AHAC subpopulations with enhanced cartilage repair capacity.