TY  - JOUR
AB  - Pancreatic ductal adenocarcinoma (PDAC) is characterized by an acidic and fibrotic stroma. The extracellular matrix (ECM) causing the fibrosis is primarily formed by pancreatic stellate cells (PSCs). The effects of the altered biomechanics and pH landscape in the pathogenesis of PDAC, however, are poorly understood. Mechanotransduction in cells has been linked to the function of mechanosensitive ion channels such as Piezo1. Here, we tested whether this channel plays crucial roles in transducing mechanical signals in the acidic PDAC microenvironment. We performed immunofluorescence, Ca2+ influx and intracellular pH measurements in PSCs and complemented them by live-cell imaging migration experiments in order to assess the function of Piezo1 channels in PSCs. We evaluated whether Piezo1 responds to changes of extracellular and/or intracellular pH in the pathophysiological range (pH 6.6 and pH 6.9, respectively). We validated our results using Piezo1-transfected HEK293 cells as a model system. Indeed, acidification of the intracellular space severely inhibits Piezo1-mediated Ca2+ influx into PSCs. In addition, stimulation of Piezo1 channels with its activator Yoda1 accelerates migration of PSCs on a two-dimensional ECM as well as in a 3D setting. Furthermore, Yoda1-activated PSCs transmit more force to the surrounding ECM under physiological pH, as revealed by measuring the dislocation of microbeads embedded in the surrounding matrix. This is paralleled by an enhanced phosphorylation of myosin light chain isoform 9 after Piezo1 stimulation. Intriguingly, upon acidification, Piezo1 activation leads to the initiation of cell death and disruption of PSC spheroids. In summary, stimulating Piezo1 activates PSCs by inducing Ca2+ influx which in turn alters the cytoskeletal architecture. This results in increased cellular motility and ECM traction, which can be useful for the cells to invade the surroundings and to detach from the tissue. However, in the presence of an acidic extracellular pH, although net Ca2+ influx is reduced, Piezo1 activation leads to severe cell stress also limiting cellular viability. In conclusion, our results indicate a strong interdependence between environmental pH, the mechanical output of PSCs and stromal mechanics, which promotes early local invasion of PDAC cells.
AU  - Kuntze, Anna
AU  - Goetsch, Ole
AU  - Fels, Benedikt
AU  - Najder, Karolina
AU  - Unger, Andreas
AU  - Wilhelmi, Marianne
AU  - Sargin, Sarah
AU  - Schimmelpfennig, Sandra
AU  - Neumann, Ilka
AU  - Schwab, Albrecht
AU  - Pethő, Zoltán
DA  - 2020-02-14
DO  - https://doi.org/10.3389/fphys.2020.00089
KW  - piezo1
KW  - pancreatic stellate cells
KW  - pancreatic cancer
KW  - fibrosis
KW  - pH homeostasis
KW  - cell migration
LA  - eng
N1  - Frontiers in Physiology 11 (2020) 89, 1-15
N1  - This work was supported by IZKF Münster (Schw2/020/18), Marie Skłodowska-Curie Innovative Training Network (ITN) Grant Agreement number: 813834-pHioniC-H2020-MSCA-ITN-2018, DFG Chembion GRK2515.
N1  - Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).
N1  - The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fphys.2020.00089/full#supplementary-material.
PY  - 2020-02-14
TI  - Protonation of Piezo1 Impairs Cell-Matrix Interactions of Pancreatic Stellate Cells
UR  - https://nbn-resolving.org/urn:nbn:de:hbz:6-67029467384
Y2  - 2024-11-22T05:27:59
ER  -