Hung Wei-Chien, Yang Jessica R, Yankaskas Christopher L, Wong Bin Sheng, Wu Pei-Hsun, Pardo-Pastor Carlos, Serra Selma A, Chiang Meng-Jung, Gu Zhizhan, Wirtz Denis, Valverde Miguel A, Yang Joy T, Zhang Jin, Konstantopoulos Konstantinos
Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA; Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA.
Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Cell Rep. 2016 May 17;15(7):1430-1441. doi: 10.1016/j.celrep.2016.04.035. Epub 2016 May 5.
Cells adopt distinct signaling pathways to optimize cell locomotion in different physical microenvironments. However, the underlying mechanism that enables cells to sense and respond to physical confinement is unknown. Using microfabricated devices and substrate-printing methods along with FRET-based biosensors, we report that, as cells transition from unconfined to confined spaces, intracellular Ca(2+) level is increased, leading to phosphodiesterase 1 (PDE1)-dependent suppression of PKA activity. This Ca(2+) elevation requires Piezo1, a stretch-activated cation channel. Moreover, differential regulation of PKA and cell stiffness in unconfined versus confined cells is abrogated by dual, but not individual, inhibition of Piezo1 and myosin II, indicating that these proteins can independently mediate confinement sensing. Signals activated by Piezo1 and myosin II in response to confinement both feed into a signaling circuit that optimizes cell motility. This study provides a mechanism by which confinement-induced signaling enables cells to sense and adapt to different physical microenvironments.
细胞采用不同的信号通路来优化在不同物理微环境中的细胞运动。然而，使细胞能够感知并响应物理限制的潜在机制尚不清楚。利用微制造装置和底物打印方法以及基于荧光共振能量转移（FRET）的生物传感器，我们报告称，当细胞从无限制空间过渡到受限空间时，细胞内Ca(2+)水平升高，导致磷酸二酯酶1（PDE1）依赖的蛋白激酶A（PKA）活性抑制。这种Ca(2+)升高需要Piezo1，一种拉伸激活的阳离子通道。此外，在无限制与受限细胞中，PKA和细胞硬度的差异调节可通过对Piezo1和肌球蛋白II的双重而非单独抑制来消除，这表明这些蛋白质可独立介导限制感知。Piezo1和肌球蛋白II响应限制而激活的信号均输入到一个优化细胞运动性的信号回路中。本研究提供了一种机制，通过该机制，限制诱导的信号使细胞能够感知并适应不同的物理微环境。
