Université PSL, Physico-Chimie Curie, CNRS UMR168, F-75005 Paris, France.
Institut Pasteur, Université Paris Cité, INRAE, USC2019, Unité Biologie et Pathogénicité Fongiques, F-75015 Paris, France.
Lab Chip. 2022 Oct 11;22(20):3898-3909. doi: 10.1039/d2lc00219a.
The cell wall is a key component of fungi. It constitutes a highly regulated viscoelastic shell which counteracts internal cell turgor pressure. Its mechanical properties thus contribute to define cell morphology. Measurements of the elastic moduli of the fungal cell wall have been carried out in many species including , a major human opportunistic pathogen. They mainly relied on atomic force microscopy, and mostly considered the yeast form. We developed a parallelized pressure-actuated microfluidic device to measure the bending stiffness of hyphae. We found that the cell wall stiffness lies in the MPa range. We then used three different ways to disrupt cell wall physiology: inhibition of beta-glucan synthesis, a key component of the inner cell wall; application of a hyperosmotic shock triggering a sudden decrease of the hyphal diameter; deletion of two genes encoding GPI-modified cell wall proteins resulting in reduced cell wall thickness. The bending stiffness values were affected to different extents by these environmental stresses or genetic modifications. Overall, our results support the elastic nature of the cell wall and its ability to remodel at the scale of the entire hypha over minutes.
细胞壁是真菌的一个关键组成部分。它构成了一个高度调控的黏弹性外壳，对抗内部细胞膨压。其机械性能有助于定义细胞形态。真菌细胞壁弹性模量的测量已在许多物种中进行，包括一种主要的人类机会致病菌。这些研究主要依赖原子力显微镜，并且大多考虑酵母形式。我们开发了一种并行压力驱动的微流控装置来测量菌丝的弯曲刚度。我们发现细胞壁的刚度在 MPa 范围内。然后，我们使用三种不同的方法来破坏细胞壁生理学：抑制β-葡聚糖合成，这是细胞壁内层的主要成分；施加高渗冲击，导致菌丝直径突然减小；删除两个编码 GPI 修饰细胞壁蛋白的基因，导致细胞壁厚度减少。这些环境压力或遗传修饰以不同程度影响了弯曲刚度值。总的来说，我们的结果支持细胞壁的弹性性质及其在数分钟内重塑整个菌丝的能力。
