Cell swelling activates stress-activated protein kinases, p38 MAP kinase and JNK, in renal epithelial A6 cells.
Osmotic shock is well recognized as one of the factors activating stress-activated protein kinases (SAPKs), p38 MAP kinase and c-Jun N-terminal kinases (JNKs). In renal epithelial A6 cells, hypo-osmotic shock transiently activated SAPKs with maximal activation at 5 min. A6 cells showed a regulatory volume decrease (RVD) after swelling when the cells were exposed to a hypo-osmotic solution. In contrast, activation of SAPKs was maintained over 90 min after hypo-osmotic shock in the presence of 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB, a Cl(-) channel blocker), which completely blocked the RVD and kept the cells continuously swelling. Exposure of the cells to a high K(+) iso-osmotic solution containing nystatin, which induces continuous cell swelling, also continuously activated SAPKs. Furthermore, membrane deformation induced by chlorpromazine activated SAPKs. These results suggest that changes in membrane tension by cell swelling or chlorpromazine, but not osmolality, are important steps for activation of SAPKs in A6 cells.
Niisato
N
N
Hospital for Sick Children, University of Toronto, Toronto, Ontario, M5G 1X8, Canada.
Post
M
M
Van Driessche
W
W
Marunaka
Y
Y
D000818:Animals; D002460:Cell Line; D048429:Cell Size; D002746:Chlorpromazine / Q000494:pharmacology; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009579:Nitrobenzoates / Q000494:pharmacology; D009761:Nystatin / Q000494:pharmacology; D009994:Osmolar Concentration; D011188:Potassium / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism*; D013312:Stress, Physiological / Q000201:enzymology*; D014982:Xenopus laevis; D048051:p38 Mitogen-Activated Protein Kinases
D009579:Nitrobenzoates; D009761:Nystatin; C058176:5-nitro-2-(3-phenylpropylamino)benzoic acid; D011494:Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D011188:Potassium; D002746:Chlorpromazine