Journal: Proceedings of the National Academy of Sciences of the United States of America
Article Title: Activation of WNK1 signaling through Piezo1
doi: 10.1073/pnas.2513155122
Figure Lengend Snippet: Hypoosmotic stress activates OSR1 and SPAK through Piezo1. ( A ) Schematic of a cell responding to osmotic stress, either hyperosmotic or hypoosmotic, resulting in changes in membrane tension and Ca 2+ influx. ( B ) Immunoblot analysis of HDMECs treated with osmotic stress in the presence of DMSO or WNK463 (1 μM) for 5 min. The bar graph is presented as mean ± SD from three independent experiments. ** P < 0.01, *** P < 0.001 (unpaired two-tailed t test, nontreated vs. WNK463-treated); # P < 0.05, ## P < 0.01, ### P < 0.001, #### P < 0.0001 (one-way ANOVA with Tukey’s multiple comparison test within the DMSO group). ( C ) siCTRL- and siPiezo1-treated HDMECs were exposed to osmotic stress for 5 min and analyzed by immunoblotting using the indicated antibodies. The results are expressed as mean ± SD. ns, not significant; * P < 0.05, ** P < 0.01, *** P < 0.001 (n = 3), unpaired two-tailed t test (siCTRL vs. siPiezo1). ( D and E ) Intracellular Ca 2+ levels were measured in Fluo-8 AM (2 µM)-labeled HDMECs exposed to isotonic, hypertonic (500 mM NaCl), or hypotonic [3:2 (v/v) deionized H 2 O/culture medium mixture] solutions, as indicated by the arrows. Data are expressed as mean ± SD (8 replicates, 2 independent experiments) ( D ). The graph represents the relative Fluo-8 AM intensity measured 3 min after osmotic stress exposure ( E ). Data are shown as mean ± SD. *** P < 0.001 (unpaired two-tailed t test, 8 replicates). ( F ) Ca 2+ -starved HDMECs, maintained in Ca 2+ /Mg 2+ -free HBSS (−Ca 2+ ) containing 0.1% FBS for 1 h, were exposed to osmotic stress in the Ca 2+ -free HBSS for 5 min. Cell lysates were analyzed by SDS-PAGE and immunoblotting. Data are shown as mean ± SD. ** P < 0.01; ns, not significant (n = 3). ( G ) Immunoblot analysis of HDMECs preincubated with DMSO or BAPTA-AM (10 μM) for 10 min, followed by exposure to osmotic stress for 5 min. The results are presented as mean ± SD. ns, not significant; * P < 0.05, ** P < 0.01, *** P < 0.001 (n = 3), unpaired two-tailed t test (DMSO-treated vs. BAPTA-AM-treated).
Article Snippet: Primary human dermal microvascular endothelial cells (HDMECs) (CRL-3243, ATCC, Manassas, VA) were grown in complete MCDB 131 medium (15-100-CV, Corning, Corning, NY) supplemented with 10% FBS (F0926, MilliporeSigma, St Louis, MO), 1% L-glutamine (25-005-CI, Corning), 1% penicillin/streptomycin (SV30010, Thermo Fisher Scientific, Waltham, MA), 1 μg/mL hydrocortisone (H0888, MilliporeSigma), and 10 ng/mL epidermal growth factor (PHG0311, Thermo Fisher Scientific).
Techniques: Membrane, Western Blot, Two Tailed Test, Comparison, Labeling, SDS Page