Oncotarget

Research Papers:

BAY 11-7085 induces glucocorticoid receptor activation and autophagy that collaborate with apoptosis to induce human synovial fibroblast cell death

Biserka Relic _, Edith Charlier, Celine Deroyer, Olivier Malaise, Sophie Neuville, Aline Desoroux, Philippe Gillet, Dominique de Seny and Michel G. Malaise

PDF  |  HTML  |  How to cite  |  Order a Reprint

Oncotarget. 2016; 7:23370-23382. https://doi.org/10.18632/oncotarget.8042

Metrics: HTML 1136 views  |   ?  


Abstract

Biserka Relic1, Edith Charlier1, Celine Deroyer1, Olivier Malaise1, Sophie Neuville1, Aline Desoroux1, Philippe Gillet2, Dominique de Seny1, Michel G. Malaise1

1Department of Rheumatology, GIGA Research, University Hospital Sart-Tilman, Liege, Belgium

2Department of Orthopedic Surgery, University Hospital Sart-Tilman, Liege, Belgium

Correspondence to:

Biserka Relic, e-mail: Biserka.Relic@chu.ulg.ac.be

Keywords: BAY 11-7085, autophagy, cell death, glucocorticoid receptor, PPAR-γ

Received: July 11, 2015    Accepted: February 28, 2016    Published: March 14, 2016

ABSTRACT

Inhibition of proapoptotic pathways in synovial fibroblasts is one of the major causes of synovial proliferation and hyperplasia in rheumatic diseases. We have shown previously that NF-κB inhibitor BAY 11-7085, through inactivation of PPAR-γ, induces apoptosis in human synovial fibroblasts. In this work we showed that BAY 11-7085 induced autophagy that preceded BAY 11-7085-induced apoptosis. Of interest, BAY 11-7085 induced Serine 211 phosphorylation and degradation of glucocorticoid receptor (GR). Glucocorticoid prednisolone induced both activation and degradation of GR, as well as autophagy in synovial fibroblasts. BAY 11-7085-induced cell death was significantly decreased with glucocorticoid inhibitor mifepristone and with inhibitors of autophagy. Both BAY 11-7085-induced autophagy and GR activation were down regulated with PPAR-γ agonist, 15d-PGJ2 and MEK/ERK inhibitor UO126. Inhibition of autophagy markedly decreased endogenous and BAY 11-7085-induced ERK phosphorylation, suggesting a positive feed back loop between ERK activation and autophagy in synovial fibroblasts. Co-transfection of MEK1 with PPAR-γ1 in HEK293 cells caused known inhibitory phosphorylation of PPAR-γ1 (Serine 112) and enhanced GR degradation, in the absence or presence of prednisolone. Furthermore, GR was both phosphorylated on Serine 211 and down regulated in synovial fibroblasts during serum starvation induced autophagy. These results showed that GR activation and PPAR-γ inactivation mediated BAY 11-7085-induced autophagy.


Creative Commons License All site content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 License.
PII: 8042