caa a22 4500 475833686 CHVBK 20180406123848.0 cr unu---uuuuu 170329e20000601xx s 000 0 eng 10.1023/A:1007824502285 doi (NATIONALLICENCE)springer-10.1023/A:1007824502285 Effect of Okadaic Acid, a Protein Phosphatase Inhibitor, on Heat Stress-Induced HSP72 Synthesis and Thermotolerance [Elektronische Daten] [Marie Joyeux, Claire Arnaud, Marie-Jeanne Richard, Derek Yellon, Pierre Demenge, Christophe Ribuot] Heat stress proteins (HSPs), in particular HSP72, seem to play a major role in cell protection against lethal stresses such as hyperthermia or ischemia. HSP synthesis is negatively regulated by protein phosphatases, which are implicated in dephosphorylation processes. In the present study, we have investigated the effect of okadaic acid (OA, a protein phosphatase inhibitor) on heat stress-induced HSP72 synthesis and thermotolerance in smooth muscle cells (SMC). SMC were heat stressed (42°C for 20 minutes) in the presence of 250 nM OA (HS+OA cells) or its vehicle (HS+V cells). Control (OA or V) cells were not heat stressed. HSP72 mRNA expression was determined 1, 1.5, 3, and 6 hours after heat stress by RT-PCR, and HSP72 synthesis was determined 6, 12, 24, 48, and 72 hours after heat stress by Western blotting. SMC survival of lethal hyperthermia (47°C for 90 minutes) was assessed 6, 24, and 48 hours after heat stress by a tetrazolium assay. The maximal expression of HSP72 mRNA was markedly prolonged in HS+OA cells (until 6 hours after heat stress) compared to HS+V cells (1 hour after heat stress). The kinetics of HSP72 synthesis and thermotolerance of SMC were not different between HS+OA and HS+V cells. Baseline HSP72 mRNA and protein expression were similar in control V and OA cells. In conclusion, okadaic acid treatment of SMC potentiated HSP72 mRNA expression without affecting heat stress-induced HSP72 synthesis and thermotolerance. Kluwer Academic Publishers, 2000 heat stress nationallicence heat stress protein nationallicence okadaic acid nationallicence protein phosphatases nationallicence smooth muscle cells nationallicence Joyeux Marie Laboratoire de Pharmacologie Cardiovasculaire Expérimentale-Biomolécules, France aut Arnaud Claire Laboratoire de Pharmacologie Cardiovasculaire Expérimentale-Biomolécules, France aut Richard Marie-Jeanne Laboratoire de Biologie du stress oxydant, Université Joseph Fourier, U.F.R. de Pharmacie, Grenoble, France aut Yellon Derek The Hatter Institute for Cardiovascular Studies, University College London Hospitals & Medical School, London, UK aut Demenge Pierre Laboratoire de Pharmacologie Cardiovasculaire Expérimentale-Biomolécules, France aut Ribuot Christophe Laboratoire de Pharmacologie Cardiovasculaire Expérimentale-Biomolécules, France aut Cardiovascular Drugs and Therapy Kluwer Academic Publishers 14/4(2000-06-01), 441-446 0920-3206 14:4<441 2000 14 10557 https://doi.org/10.1023/A:1007824502285 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1007824502285 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Joyeux Marie Laboratoire de Pharmacologie Cardiovasculaire Expérimentale-Biomolécules, France aut NATIONALLICENCE 700 1- Arnaud Claire Laboratoire de Pharmacologie Cardiovasculaire Expérimentale-Biomolécules, France aut NATIONALLICENCE 700 1- Richard Marie-Jeanne Laboratoire de Biologie du stress oxydant, Université Joseph Fourier, U.F.R. de Pharmacie, Grenoble, France aut NATIONALLICENCE 700 1- Yellon Derek The Hatter Institute for Cardiovascular Studies, University College London Hospitals & Medical School, London, UK aut NATIONALLICENCE 700 1- Demenge Pierre Laboratoire de Pharmacologie Cardiovasculaire Expérimentale-Biomolécules, France aut NATIONALLICENCE 700 1- Ribuot Christophe Laboratoire de Pharmacologie Cardiovasculaire Expérimentale-Biomolécules, France aut NATIONALLICENCE 773 0- Cardiovascular Drugs and Therapy Kluwer Academic Publishers 14/4(2000-06-01), 441-446 0920-3206 14:4<441 2000 14 10557 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer