Selective Non-Steroidal Glucocorticoid Receptor Agonists Attenuate Inflammation but Do Not Impair Intestinal Epithelial Cell Restitution In Vitro
ABSTRACT Despite the excellent anti-inflammatory and immunosuppressive action of glucocorticoids (GCs), their use for the treatment of inflammatory bowel disease (IBD) still carries significant risks in terms of frequently occurring severe side effects, such as the impairment of intestinal tissue repair. The recently-introduced selective glucocorticoid receptor (GR) agonists (SEGRAs) offer anti-inflammatory action comparable to that of common GCs, but with a reduced side effect profile.
The in vitro effects of the non-steroidal SEGRAs Compound A (CpdA) and ZK216348, were investigated in intestinal epithelial cells and compared to those of Dexamethasone (Dex). GR translocation was shown by immunfluorescence and Western blot analysis. Trans-repressive effects were studied by means of NF-κB/p65 activity and IL-8 levels, trans-activation potency by reporter gene assay. Flow cytometry was used to assess apoptosis of cells exposed to SEGRAs. The effects on IEC-6 and HaCaT cell restitution were determined using an in vitro wound healing model, cell proliferation by BrdU assay. In addition, influences on the TGF-β- or EGF/ERK1/2/MAPK-pathway were evaluated by reporter gene assay, Western blot and qPCR analysis.
Dex, CpdA and ZK216348 were found to be functional GR agonists. In terms of trans-repression, CpdA and ZK216348 effectively inhibited NF-κB activity and IL-8 secretion, but showed less trans-activation potency. Furthermore, unlike SEGRAs, Dex caused a dose-dependent inhibition of cell restitution with no effect on cell proliferation. These differences in epithelial restitution were TGF-β-independent but Dex inhibited the EGF/ERK1/2/MAPK-pathway important for intestinal epithelial wound healing by induction of MKP-1 and Annexin-1 which was not affected by CpdA or ZK216348.
Collectively, our results indicate that, while their anti-inflammatory activity is comparable to Dex, SEGRAs show fewer side effects with respect to wound healing. The fact that SEGRAs did not have a similar effect on cell restitution might be due to a different modulation of EGF/ERK1/2 MAPK signalling.
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- "In that respect, 2-(4-acetoxyphenyl)-2-chloro-N-methylethy- lammonium chloride, named compound A (CpdA), a plant-derived precursor of phenyl aziridine, is a non-steroidal SEGRM that is under intensive investigation      . CpdA differs from classic GCs in size and structure. "
ABSTRACT: The glucocorticoid receptor functions as a ligand-dependent transcription factor that positively or negatively regulates the transcription of various specific target genes. Not only steroidal glucocorticoids can bind and activate the glucocorticoid receptor, but also the intensively examined non-steroidal selective glucocorticoid receptor modulators can do so, albeit with a select effector profile skewed to glucocorticoid receptor transrepression. Glucocorticoids are widely used to treat inflammatory afflictions, but also as anti-cancer therapies or adjuvants thereof. As the impact of glucocorticoids and selective glucocorticoid receptor modulators has scarcely been researched in this setting, we focused on colon cancer and its stromal environment, in particular the stromal myofibroblasts, which are known to influence cancer cells via paracrine signaling.The Journal of Steroid Biochemistry and Molecular Biology 02/2015; 149. DOI:10.1016/j.jsbmb.2015.02.002 · 4.05 Impact Factor
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ABSTRACT: Glucocorticoids (GCs) are essential steroid hormones for homeostasis, development, metabolism, and cognition and possess anti-inflammatory and immunosuppressive actions. Since glucocorticoid receptor II (GR) is nearly ubiquitous, chronic activation or depletion of GCs leads to dysfunction of diverse organs, including the heart and blood vessels, resulting predominantly from changes in gene expression. Most studies, therefore, have focused on the genomic effects of GC to understand its related pathophysiological manifestations. The nongenomic effects of GCs clearly differ from well-known genomic effects, with the former responding within several minutes without the need for protein synthesis. There is increasing evidence that the nongenomic actions of GCs influence various physiological functions. To develop a GC-mediated therapeutic target for the treatment of cardiovascular disease, understanding the genomic and nongenomic effects of GC on the cardiovascular system is needed. This article reviews our current understanding of the underlying mechanisms of GCs on cardiovascular diseases and stress, as well as how nongenomic GC signaling contributes to these conditions. We suggest that manipulation of GC action based on both GC and GR metabolism, mitochondrial impact, and the action of serum- and glucocorticoid-dependent kinase 1 may provide new information with which to treat cardiovascular diseases.Pflügers Archiv - European Journal of Physiology 09/2012; 464(6). DOI:10.1007/s00424-012-1155-2 · 3.07 Impact Factor
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ABSTRACT: Idiopathic pulmonary fibrosis (IPF) is an aging-related lung disorder characterized by expansion of the myofibroblast population and aberrant lung remodeling. Dehydroepiandrosterone (DHEA), a steroid pro-hormone, decreases with age but an exaggerated decline has been associated with chronic-degenerative diseases.We quantified the plasma levels of DHEA and its sulfated form (DHEA-S) in 137 IPF patients and 58 controls and examined the effects of DHEA on human lung fibroblasts.Plasmatic DHEA/DHEA-S were significantly decreased in male IPF patients, (DHEA, median (max-min): 4.4 (0.2-29.2) versus 6.7 (2.1-15.2) ng·mL(-1); p<0.01; DHEA-S, median: 47 (15.0-211) versus 85.2 (37.6-247.0) μg·dl(-1); p<0.001), while in females only DHEA-S was significantly decreased (median: 32.6 (15.0-303.0) versus 68.3 (16.4-171); p<0.001). DHEA caused a decrease of fibroblast proliferation and a ∼2-fold increase of fibroblast apoptosis, likely through the intrinsic pathway with activation of caspase-9. This effect was accompanied by upregulation of several pro-apoptotic proteins (Bax and cyclin-dependent kinase-inhibitor CDNK1A) and downregulation of anti-apoptotic proteins such as c-IAP1/c-IAP2. DHEA also caused a significant decrease of TGF-β1-induced collagen production and fibroblast to myofibroblast differentiation, and inhibited PDGF-induced fibroblast migration.These findings demonstrate a disproportionate decrease of DHEA/DHEA-S in IPF patients and indicate that this molecule has multiple antifibrotic properties.European Respiratory Journal 11/2012; 42(5). DOI:10.1183/09031936.00027412 · 7.13 Impact Factor