The Role of Extracellular Matrix Expression, ERK1/2 Signaling and Cell Cohesiveness for Cartilage Yield from iPSCs
The Role of Extracellular Matrix Expression, ERK1/2 Signaling and Cell Cohesiveness for Cartilage Yield from iPSCs
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DOI：
10.3390/ijms20174295
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发表时间：
2019-09-01
影响因子：
5.6
通讯作者：
Richter, Wiltrud
中科院分区：
文献类型：
--
作者：
Buchert, Justyna;Diederichs, Solvig;Richter, Wiltrud
目前涉及软骨细胞或间充质基质细胞（MSC）的疗法在损伤后恢复软骨特性方面仍然效率低下。诱导多能干细胞（iPSC）来源的间充质祖细胞（iMPCs）由于其高度的增殖和分化潜能而被提出作为有希望的替代细胞来源。然而，体外软骨形成过程中观察到的细胞损失目前是从iPSC建立关节软骨细胞产生的瓶颈。在寻找低iPSC衍生的软骨组织产率的潜在候选机制中，比较iMPC和MSC之间的全局转录组，并通过缩合测定分析细胞性质。iMPC具有比MSC更幼稚的间充质基因特征，具有更少的成肌纤维细胞样特征，包括显著更低的ECM和整合素配体相关以及更低的α-平滑肌肌动蛋白表达。这与更少的底物和更多的细胞-细胞粘附、受损的聚集体形成和因此较差的iMPC-颗粒的粘性组织性质相关。随着促存活ECM分子如核心蛋白聚糖、胶原VI、光蛋白聚糖和层粘连蛋白的表达沿着降低，iMPC群体与MSC相比具有显著更低的活性ERK 1/2。总的来说，这项研究提出，这种ECM和整合素配体的短缺，以及促存活ERK 1/2活性不足，解释了在沉淀形成过程中非聚集性iMPC亚组分的损失和早期沉淀中细胞存活率的降低。增强iMPC中的ECM产生和相关信号传导可能是一种有前途的新手段，以丰富具有促存活因子的指导性微环境，从而提高iPSC的最终软骨组织产量。
Current therapies involving chondrocytes or mesenchymal stromal cells (MSCs) remain inefficient in restoring cartilage properties upon injury. The induced pluripotent stem-cell (iPSC)-derived mesenchymal progenitor cells (iMPCs) have been put forward as a promising alternative cell source due to their high proliferation and differentiation potential. However, the observed cell loss during in vitro chondrogenesis is currently a bottleneck in establishing articular chondrocyte generation from iPSCs. In a search for candidate mechanisms underlying the low iPSC-derived cartilage tissue yield, global transcriptomes were compared between iMPCs and MSCs and the cell properties were analyzed via a condensation assay. The iMPCs had a more juvenile mesenchymal gene signature than MSCs with less myofibroblast-like characteristics, including significantly lower ECM- and integrin-ligand-related as well as lower alpha -smooth-muscle-actin expression. This correlated with less substrate and more cell-cell adhesion, impaired aggregate formation and consequently inferior cohesive tissue properties of the iMPC-pellets. Along lower expression of pro-survival ECM molecules, like decorin, collagen VI, lumican and laminin, the iMPC populations had significantly less active ERK1/2 compared to MSCs. Overall, this study proposes that this ECM and integrin-ligand shortage, together with insufficient pro-survival ERK1/2-activity, explains the loss of a non-aggregating iMPC sub-fraction during pellet formation and reduced survival of cells in early pellets. Enhancing ECM production and related signaling in iMPCs may be a promising new means to enrich the instructive microenvironment with pro-survival cues allowing to improve the final cartilage tissue yield from iPSCs.