Project description:Cortisol, the central stress hormone in humans, activates the glucocorticoid receptor (GR). Anti-inflammatory effects are the most important pharmaceutical effects mediated by the GR. Inasmuch as electrophilic cyclopentenone prostaglandin 15-deoxy-M-NM-^T12,14-prostaglandin J2 (15d-PGJ2) has potent anti-inflammatory properties and activates the SUMOylation pathway, we have investigated the effect of 15d-PGJ2 on glucocorticoid signaling and receptor SUMOylation. To this end, we studied isogenic HEK293 cells expressing either wild-type GR or SUMOylation-defective GR. Interestingly, 15d-PGJ2 triggered SUMO-2/3 modification in the primary SUMOylation sites of the GR. Gene expression profiling and pathway analyses indicate that 15d-PGJ2 inhibits GR signaling in a genome-wide fashion that is significantly dependent on the GR SUMOylation sites. Chromatin immunoprecipitation assays showed that the repressive effect of 15d-PGJ2 on GR target gene expression occurs in parallel with the inhibition of receptor binding to the target gene chromatin. Furthermore, depletion of the sole SUMO E2 conjugase UBC9 from HEK293 cells confirmed the involvement of active SUMOylation in the regulatory process. Taken together, our data indicate that GR SUMOylation modulates the glucocorticoid signaling during acute cell stress. Our data also suggest that GR SUMOylation modulates crosstalk of the glucocorticoid signaling with other transcription factors that are responsive to cell stress. Total RNA isolated from isogenic HEK293 cell lines stably expressing either wild-type GR (wtGR) or SUMOylation-defective GR (GR3KR) treated with 100 nM of dexamethasone (dex) in the presence or absence of 5 M-BM-5M 15d-PGJ2 for 6h. All conditions are performed in triplicate
Project description:Cortisol, the central stress hormone in humans, activates the glucocorticoid receptor (GR). Anti-inflammatory effects are the most important pharmaceutical effects mediated by the GR. Inasmuch as electrophilic cyclopentenone prostaglandin 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) has potent anti-inflammatory properties and activates the SUMOylation pathway, we have investigated the effect of 15d-PGJ2 on glucocorticoid signaling and receptor SUMOylation. To this end, we studied isogenic HEK293 cells expressing either wild-type GR or SUMOylation-defective GR. Interestingly, 15d-PGJ2 triggered SUMO-2/3 modification in the primary SUMOylation sites of the GR. Gene expression profiling and pathway analyses indicate that 15d-PGJ2 inhibits GR signaling in a genome-wide fashion that is significantly dependent on the GR SUMOylation sites. Chromatin immunoprecipitation assays showed that the repressive effect of 15d-PGJ2 on GR target gene expression occurs in parallel with the inhibition of receptor binding to the target gene chromatin. Furthermore, depletion of the sole SUMO E2 conjugase UBC9 from HEK293 cells confirmed the involvement of active SUMOylation in the regulatory process. Taken together, our data indicate that GR SUMOylation modulates the glucocorticoid signaling during acute cell stress. Our data also suggest that GR SUMOylation modulates crosstalk of the glucocorticoid signaling with other transcription factors that are responsive to cell stress.
Project description:We examined the alternation of gene expression by MCC-555, rosiglitazone (RGZ) and 15-deoxy-Δ12, 14-prostaglandin J2 (PGJ2) in human colorectal adenocarcinoma HCT-116 cells. Keywords: effects of PPAR-gamma agonists
Project description:15-deoxy-delta12,14-prostaglandin J2 (15d-PGJ2) is an endogenous anti-inflammatory lipid derived from PGD2. One potential mechanism for its activity is the covalent modification of cellular proteins, via a reactive alpha,beta-unsaturated carbonyl group in its cyclopentenone ring, which in turn alters protein function. In order to identify the target proteins covalently modified by 15d-PGJ2 in human aortic endothelial cell (EC), EC were treated with biotinylated-15d-PGJ2, the modified proteins extracted by Neutravidin affinity-purification and the proteins were identified by LTQ Orbitrap mass spectrometer.
Project description:Cellular senescence is a stress or damage response that causes a permanent proliferative arrest and secretion of numerous factors with potent biological activities. This senescence-associated secretory phenotype (SASP) has been characterized largely for secreted proteins that participate in embryogenesis, wound healing, inflammation and many age-related pathologies. By contrast, lipid components of the SASP are understudied. We show that senescent cells activate the biosynthesis of several oxylipins that promote segments of the SASP and reinforce the proliferative arrest. Notably, senescent cells synthesize and accumulate an unstudied intracellular prostaglandin, 1a,1b-dihomo-15-deoxy-delta-12,14-prostaglandin J2. Released 15-deoxy-delta-12,14-prostaglandin J2 is a biomarker of senolysis in culture and in vivo. This and other prostaglandin D2-related lipids promote the senescence arrest and SASP by activating RAS signaling. These data identify an important aspect of cellular senescence and a method to detect senolysis
Project description:Despite the importance of lipid mediators in stress and depression and their link to inflammation, the influence of stress on these mediators and their role in inflammation is not fully understood. This study used RNA-seq, LC-MS/MS, and flow cytometry analyses in a mouse model subjected to chronic social defeat stress to explore the effects of acute and chronic stress on lipid mediators, gene expression, and cell population in the bone marrow and spleen. We observed that chronic stress in the bone marrow precipitated a persistent lymphoid-to-myeloid transition, accompanied by corresponding gene expression changes. This change was associated with decreased levels of 15-deoxy-d12,14-prostaglandin J2, a lipid mediator that inhibits inflammation. Conversely, in the spleen, chronic stress led to a transient lymphoid-to-myeloid transition, alongside gene expression patterns suggestive of extramedullary hematopoiesis. These changes were linked to lower levels of 12-HEPE and resolvins, both critical for inhibiting and resolving inflammation. Our findings highlight the significant role of anti-inflammatory and pro-resolving lipid mediators in the immune responses induced by chronic stress in the bone marrow and spleen. This study paves the way for understanding how these lipid mediators contribute to the immune mechanisms of stress and depression.
Project description:Human macrophages secrete extracellular vesicles loaded with numerous immunoregulatory proteins. Here we employed high throughput quantitative proteomics to characterize the modulation of vesicle-mediated protein secretion during non-canonical caspase-4/5-dependent inflammasome activation. We show that human macrophages activate robust caspase-4- dependent extracellular vesicle secretion upon transfection of LPS, and this process is also partially dependent on NLRP-3 and caspase-5. Similar effect occurs with delivery of the LPS with E. coli-derived outer membrane vesicles. Moreover, sensitization of the macrophages through TLR4 prior to LPS transfection dramatically augments the EV-mediated protein secretion. Our data demonstrate that this process differs significantly from ATP-induced vesiculation, and is dependent on autocrine interferon signal associated with TLR4 activation. TLR4 activation preceding the non-canonical inflammasome activation significantly enhances vesicle-mediated secretion of inflammasome components caspase-1, ASC and lytic cell death effectors GSDMD, MLKL and NINJ1, suggesting that inflammatory EV transfer may exert paracrine effects in recipient cells. Moreover, using bioinformatic methods, we identify 15-deoxy-delta-12,14-prostaglandin J2 and parthenolide as inhibitors of caspase-4-mediated inflammation and vesicle secretion, indicating potential new therapeutic potential of these anti-inflammatory drugs.
Project description:Although the COVID-19 pandemic has ended, it is important to understand the pathology of severe SARS-CoV-2 infection associated with respiratory failure and high mortality. In this study, a proteomics approach using nano-HPLC-MS/MS (QExactive HF) was used to compare the plasma proteome of COVID-19 survivors (COVID-19; n=10) and deceased individuals (CovDeath; n=10) with that of healthy individuals (Ctr; n=10). The effects of SARS-CoV-2 infection on the alteration of plasma proteins by lipid peroxidation products such as 4-hydroxynonenal (4-HNE), malondialdehyde (MDA) and 15-deoxy-12,14-prostaglandin J2 (15d-PGJ2) were also examined. The results suggest that the development of COVID-19 strongly alters the expression of proteins involved in the regulation of exocytosis and platelet degranulation. These changes were most pronounced in the CovDeath group. In addition, a significant increase in proteins modified with reactive aldehydes was observed in all patients. In the COVID-19 and CovDeath groups, the levels of 4-HNE adducts increased 2- and 3-fold, respectively, whereas MDA adducts increased 7- and 2.5-fold, respectively. Signaling kinases and proinflammatory proteins were particularly affected by these modifications, and the amount of 4-HNE modifications confirmed previous findings on the relevance of 4-HNE in disease pathogenesis and lethal outcome. Protein adducts with 15d-PGJ2 were increased 2.5-fold in COVID-19 patients, including modifications of proteins such as p53 and STAT3, whereas CovDeath showed a decrease of approximately 60% compared with Ctr. It can be assumed that the observed changes in protein expression and modification in COVID-19 are unlikely to be used as prognostic biomarkers because they are also present in the other inflammatory diseases. However, larger studies may prove that the extent and the nature of protein modifications in plasma may be a predictor of the course of SARS-CoV-2 infection.
Project description:Glucocorticoid receptor (GR) is an essential transcription factor (TF), controlling metabolism, development and immune responses. SUMOylation regulates chromatin occupancy and target gene expression of GR in a locus-selective manner, but the mechanism of regulation has remained elusive. Here, we identify the protein network around chromatin-bound GR by using selective isolation of chromatin-associated proteins and show that the network is affected by receptor SUMOylation, with several nuclear receptor coregulators and chromatin modifiers preferring interaction with SUMOylation-deficient GR and proteins implicated in transcriptional repression preferring interaction with SUMOylation-competent GR. This difference is reflected in our chromatin binding, chromatin accessibility and gene expression data, showing that the SUMOylation-deficient GR is more potent in binding and opening chromatin at glucocorticoid-regulated enhancers and inducing expression of target loci. Blockage of SUMOylation by a SUMO-activating enzyme inhibitor (ML-792) phenocopied to a large extent the consequences of GR SUMOylation deficiency on chromatin binding and target gene expression. Our results thus show that SUMOylation modulates the specificity of GR by regulating its chromatin protein network and accessibility at GR-bound enhancers. We speculate that many other SUMOylated TFs utilize a similar regulatory mechanism.
Project description:Glucocorticoid receptor (GR) is an essential transcription factor (TF), controlling metabolism, development and immune responses. SUMOylation regulates chromatin occupancy and target gene expression of GR in a locus-selective manner, but the mechanism of regulation has remained elusive. Here, we identify the protein network around chromatin-bound GR by using selective isolation of chromatin-associated proteins and show that the network is affected by receptor SUMOylation, with several nuclear receptor coregulators and chromatin modifiers preferring interaction with SUMOylation-deficient GR and proteins implicated in transcriptional repression preferring interaction with SUMOylation-competent GR. This difference is reflected in our chromatin binding, chromatin accessibility and gene expression data, showing that the SUMOylation-deficient GR is more potent in binding and opening chromatin at glucocorticoid-regulated enhancers and inducing expression of target loci. Blockage of SUMOylation by a SUMO-activating enzyme inhibitor (ML-792) phenocopied to a large extent the consequences of GR SUMOylation deficiency on chromatin binding and target gene expression. Our results thus show that SUMOylation modulates the specificity of GR by regulating its chromatin protein network and accessibility at GR-bound enhancers. We speculate that many other SUMOylated TFs utilize a similar regulatory mechanism.