Centre for Healthcare Science and Technology, Indian Institute of Engineering Science and Technology, Shibpur, India.
Department of Aerospace and Applied Mechanics, Indian Institute of Engineering Science and Technology, Shibpur, India.
Stem Cell Rev Rep. 2024 Apr;20(3):755-768. doi: 10.1007/s12015-023-10656-5. Epub 2023 Nov 16.
Mesenchymal to epithelial transition (MET) is instrumental in embryogenesis, tissue repair, and wound healing while the epithelial to mesenchymal transition (EMT) plays role in carcinogenesis. Alteration in microenvironment can modulate cellular signaling and induce EMT and MET. However, modulation of microenvironment to induce MET has been relatively less explored. In this work, effect of matrix stiffness in mediating MET in umbilical cord-derived mesenchymal stem cells (UCMSC) is investigated. Differential segregation of cell fate determinant proteins is one of the key factors in mediating altered stem cell fates through MET even though the genesis of apicobasal polarity remains ambiguous. Herein, it is also attempted to decipher if microenvironment-induced asymmetric cell division has a role to play in driving the cells toward MET. UCMSC cultured on stiffer PDMS matrices resulted in significantly (p < 0.05) higher expression of mechanotransduction proteins. It was also observed that stiffer matrices mediated significant (p < 0.05) upregulation of the polarity proteins and cell fate determinant protein, and epithelial marker proteins over lesser stiff substrates. On the contrary, expression of inflammatory and mesenchymal markers was reduced significantly (p < 0.05) on the stiffer matrices. Cell cycle analysis showed a significant increase in the G1 phase among the cells seeded on stiffer matrices. Transcriptomic studies validated higher expression of epithelial markers genes and lower expression of EMT markers. The transition from mesenchymal to epithelial phenotype depending on the gradation in matrix stiffness is successfully demonstrated. A computational machine learning model was developed to validate stiffness-MET correlation with 94% accuracy. The cross-boundary trans-lineage differentiation capability of MSC on bioengineered substrates can be used as a potential tool in tissue regeneration, organogenesis, and wound healing applications. In our present study, we deciphered the correlation between YAP/TAZ mechanotransduction pathway, EMT signaling pathway, and asymmetric cell division in mediating MET in MSC in a substrate stiffness-dependent manner. It is inferred that the stiffer PDMS matrices facilitate the transition from mesenchymal to epithelial state of MSC. Further, our study also proposed a scoring system to sort MSC from an intermediate hybrid E/M population while undergoing graded MET on matrices of different stiffnesses using a machine learning technique. This proposed scoring system can provide information regarding the E/M state of MSC on different bioengineered constructs based on their biophysical properties which may help in the proper choice of biomaterials in complex tissue-engineering applications.
间质上皮转化（MET）在胚胎发生、组织修复和伤口愈合中起着重要作用，而上皮间质转化（EMT）在癌发生中起着作用。微环境的改变可以调节细胞信号转导，并诱导 EMT 和 MET。然而，诱导 MET 的微环境调节相对较少被探索。在这项工作中，研究了基质硬度在调节脐带间充质干细胞（UCMSC）中的 MET 中的作用。细胞命运决定蛋白的差异分离是通过 MET 介导改变干细胞命运的关键因素之一，尽管顶端基底极性的起源仍然不清楚。在此，还试图确定微环境诱导的不对称细胞分裂是否在推动细胞向 MET 方向发展中发挥作用。在较硬的 PDMS 基质上培养的 UCMSC 导致机械转导蛋白的表达显著增加（p<0.05）。还观察到，较硬的基质介导了极性蛋白和细胞命运决定蛋白的显著上调（p<0.05），以及上皮标记蛋白在较软基质上的表达。相反，在较硬的基质上，炎症和间充质标记物的表达显著降低（p<0.05）。细胞周期分析显示，在较硬的基质上接种的细胞中 G1 期显著增加。转录组学研究验证了上皮标记基因的高表达和 EMT 标记基因的低表达。根据基质硬度的梯度，成功地证明了从间充质到上皮表型的转变。开发了一个计算机器学习模型来验证刚度-MET 相关性，准确率为 94%。MSC 在生物工程基底上的跨边界跨谱系分化能力可以用作组织再生、器官发生和伤口愈合应用的潜在工具。在我们目前的研究中，我们在基质硬度依赖性方式下，解析了 YAP/TAZ 机械转导途径、EMT 信号通路和不对称细胞分裂在 MSC 中的 MET 中的相关性。可以推断，较硬的 PDMS 基质有利于 MSC 从间充质状态向上皮状态的转变。此外，我们的研究还提出了一种评分系统，通过机器学习技术，对不同硬度基质上进行梯度 MET 的 MSC 从中间混合 E/M 群体中进行分类。该评分系统可以根据生物工程结构的生物物理特性，为不同生物工程构建体上的 MSC 的 E/M 状态提供信息，这可能有助于在复杂的组织工程应用中选择合适的生物材料。
