Occhetta Paola, Isu Giuseppe, Lemme Marta, Conficconi Chiara, Oertle Philipp, Räz Christian, Visone Roberta, Cerino Giulia, Plodinec Marija, Rasponi Marco, Marsano Anna
Department of Biomedicine, University of Basel, Hebelstrasse 20, CH-4031 Basel, Switzerland.
Biozentrum and the Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland.
Integr Biol (Camb). 2018 Mar 1;10(3):174-183. doi: 10.1039/c7ib00199a. Epub 2018 Mar 13.
In vitro cardiac models able to mimic the fibrotic process are paramount to develop an effective anti-fibrosis therapy that can regulate fibroblast behaviour upon myocardial injury. In previously developed in vitro models, typical fibrosis features were induced by using scar-like stiffness substrates and/or potent morphogen supplementation in monolayer cultures. In our model, we aimed to mimic in vitro a fibrosis-like environment by applying cyclic stretching of cardiac fibroblasts embedded in three-dimensional fibrin-hydrogels alone. Using a microfluidic device capable of delivering controlled cyclic mechanical stretching (10% strain at 1 Hz), some of the main fibrosis hallmarks were successfully reproduced in 7 days. Cyclic strain indeed increased cell proliferation, extracellular matrix (ECM) deposition (e.g. type-I-collagen, fibronectin) and its stiffness, forming a scar-like tissue with superior quality compared to the supplementation of TGFβ1 alone. Taken together, the observed findings resemble some of the key steps in the formation of a scar: (i) early fibroblast proliferation, (ii) later phenotype switch into myofibroblasts, (iii) ECM deposition and (iv) stiffening. This in vitro scar-on-a-chip model represents a big step forward to investigate the early mechanisms possibly leading later to fibrosis without any possible confounding supplementation of exogenous potent morphogens.
能够模拟纤维化过程的体外心脏模型对于开发一种有效的抗纤维化疗法至关重要，该疗法可以在心肌损伤时调节成纤维细胞的行为。在先前开发的体外模型中，典型的纤维化特征是通过在单层培养中使用瘢痕样硬度的底物和/或添加强效形态发生素来诱导的。在我们的模型中，我们旨在通过单独对嵌入三维纤维蛋白水凝胶中的心脏成纤维细胞施加循环拉伸，在体外模拟类似纤维化的环境。使用能够提供可控循环机械拉伸（1Hz频率下10%应变）的微流控装置，在7天内成功再现了一些主要的纤维化特征。循环应变确实增加了细胞增殖、细胞外基质（ECM）沉积（如I型胶原蛋白、纤连蛋白）及其硬度，形成了一种质量优于单独添加TGFβ1的瘢痕样组织。综上所述，观察到的结果类似于瘢痕形成中的一些关键步骤：（i）早期成纤维细胞增殖，（ii）后期表型转变为肌成纤维细胞，（iii）ECM沉积，以及（iv）硬化。这种体外芯片瘢痕模型代表了向前迈出的一大步，可用于研究可能导致后期纤维化的早期机制，而无需任何可能产生混淆的外源性强效形态发生素补充。
