Periodic Reporting for period 4 - SILENCE (Mechanisms of Gene Silencing by the Glucocorticoid Receptor)
Periodo di rendicontazione: 2020-02-01 al 2021-07-31
With SILENCE, we proposed to decipher the unresolved molecular paradox of positive versus negative gene regulation by the Glucocorticoid Receptor. Inflammation is known to contribute to the pathogenesis of numerous human illnesses, including cancer, autoimmune disorders, diabetes and cardiovascular disease. Understanding the specific mechanisms involved in the silencing of inflammatory gene expression carries transformative potential for novel therapies and safer drugs. In addition the clinical relevance of this project is underscored by the fact that currently, the gold standard of care for Covid-19 patients hospitalized with respiratory support, mainly consists of these anti-inflammatory steroids.
The ERC Starting Grant ‘SILENCE’ was focused on the identification of DNA-encoded factors (proteins, noncoding RNAs or cis-regulatory sequences) mediating transcriptional silencing of inflammatory genes by the Glucocorticoid Receptor (GR).The molecular mechanisms of how GR turns off inflammatory gene expression are far from understood, which is what this project was addressing.
Furthermore we have successfully identified additional modulators of GR target locus binding proteins belonging to the STAT family (Quagliarini et al 2019).
By using state-of-the-art techniques such as siRNA, Crispr/Cas9 and proteomics, we were also able to identify and characterize important co-regulators of the anti-inflammatory GR transcriptional complex that belong to the chromatin landscape, such as the COMPASS-H3K4 methyltransferase complex and components of the SWI/SNF complex. Finally, we found several noncoding RNAs, such as miRNAs, eRNAs, uORFs, lncRNAs, which are differentially regulated in activated macrophages in response to GR ligand (Greulich et al 2021). In summary, we have performed the experiments described in the grant proposal, with minor technical modifications, as methods were evolving and improving.
Overall, our discovery has important implications for the development of novel glucocorticoid receptor agonists or modulators with lower side-effect profiles and for our understanding of transcriptional regulation by GR.