Inhibition of AP-1 by the glucocorticoid-inducible protein GILZ

Unravelling immunomodulatory effects of bisphenol A substitutes on human macrophages, T and B lymphocytes using in vitro models

This study investigates the immunomodulatory effects of BPA substitutes using in silico and in vitro approaches. A comprehensive in silico screening with Endocrine Disruptome of BPA and its 25 substitutes revealed that BPG, BPS-MAE, BPS-MPE, BPPH and PF201 have the highest potential to bind nuclear receptors. Based on the in silico ranking, 12 compounds were selected and tested in vitro to investigate their effects on THP-1 derived macrophages, Jurkat T cells and LCLs. The metabolic activity tests showed that BPA has IC50 values of 99-182 µM, while the values for BPG, BPPH and BPP are 5-10 times lower. Comparison of the IC50 values with the logP of the tested compounds showed that the BPA analogues affect cell viability in proportion to their lipophilicity (R2 = 0.9185). The results of the cytokine release assays showed that the BPA substitutes generally stimulated the proinflammatory response in THP-1 macrophages in a statistically significant manner when exposed to the environmentally relevant concentrations and suppressed it in the micromolar range in all cell lines tested. Further analysis using RamosBlue reporter cells indicated that BPAP, BPG, BPP and BPPH alter the NF-κB/AP-1 signalling pathway. Moreover, BPAP, BPG, BPP, BPPH, BPS-MAE, BPS-MPE, BTUM and PF201 were predicted in silico to be TLR4-MyD88 inhibitors. The overall results of this study identify BPG, BPP, BPPH, BPZ and TCBPA as BPA analogues with the highest immunomodulatory potential. In addition, the immunomodulatory potential of the BPA alternatives Pergafast201 and BTUM was confirmed in vitro for the first time. This study emphasises the need for cautious evaluation of BPA substitutes due to their potential immunomodulatory effect, which could significantly affect public health.

Deacetylation by SIRT6 increases the stability of GILZ to suppress NSCLC cell migration and invasion

Glucocorticoid-induced leucine zipper (GILZ) plays a role in cancer cell proliferation in several tumor types. However, in our present study, GILZ was demonstrated to be a metastasis regulator but not a proliferation regulator in non-small cell lung cancer (NSCLC). The overexpression of GILZ had no significant effect on the proliferation of NSCLC cells but inhibited their metastasis by targeting the epithelial-mesenchymal transition pathway. The deacetylase SIRT6, a key regulator of protein stability, can enhance the stability of the GILZ protein by mediating its deacetylation, which prevents ubiquitination and degradation. This process ultimately enhances the inhibitory effect of GILZ on the migration and invasion of NSCLC cells. Thus, GILZ may be a promising new therapeutic target for tumor metastasis.

Oxidative Stress and Antioxidants in Pediatric Asthma's Evolution and Management

Within the pediatric population, bronchial asthma is one of the most prevalent chronic respiratory system diseases. The number of exacerbations, severity, and duration of symptoms all have a significant impact on children's life quality. In the last decades, the prevention and management strategies of this pathology have focused on maintaining or even increasing the pulmonary function to maximum levels in early childhood, as it has been demonstrated that functional deficits at this level occurring before school age cause pathological manifestations later, in adulthood. The epithelium of the airways and implicitly that of the lung is the first barrier against the lesions caused by pro-oxidative factors. Both oxidative and antioxidative factors can be of endogenous origin (produced by the body) or exogenous (from the environment or diet). Good functioning of antioxidant defense mechanisms from the molecular level to the tissue level, and a balance between pro-oxidative factors and anti- oxidative factors, influence the occurrence of compensatory mechanisms at the level of the respiratory epithelium, causing the delay of local responses to the stress induced by chronic inflammation (bronchial remodeling, thickening of airway smooth muscles, bronchoconstriction, bronchial hyper-reactivity). These mechanisms underlie the pathophysiological changes in asthma. Numerous studies carried out among the pediatric population inclusively have demonstrated the effectiveness of antioxidants in the prophylaxis, slowing down and preventing the progression of this pathology. This review complements the scientific articles, aiming at emphasizing the complexity of oxidative physio-pathological pathways and their importance in the occurrence, development, and therapeutic response in asthma, providing a good understanding of the relationship between oxidative and antioxidative factors, and being a source of future therapeutic strategies.

Multiple functions of the herpesvirus UL14 gene product in viral infection

Herpesviruses are a family of double-stranded DNA viruses with a tegument structure and a genome composed of a single sequence and terminal repeat (TR) sequences. The herpesvirus UL14 gene encodes the protein UL14 (pUL14), which has various subcellular localizations and plays a vital role in regulating immediate-early (IE) gene transcription and expression, influences the intracellular localization patterns of several proteins belonging to the capsid and the DNA packaging machinery, participates in secondary envelopment, and influences viral particle release. Additionally, pUL14 has roles in maintaining cellular homeostasis and preventing apoptosis. This review discusses how pUL14 engages in the life cycle of herpesviruses and provides new ideas for further research on pUL14's function in viral infection.

Targeting osteoblastic 11β-HSD1 to combat high-fat diet-induced bone loss and obesity

Excessive glucocorticoid (GC) action is linked to various metabolic disorders. Recent findings suggest that disrupting skeletal GC signaling prevents bone loss and alleviates metabolic disorders in high-fat diet (HFD)-fed obese mice, underpinning the neglected contribution of skeletal GC action to obesity and related bone loss. Here, we show that the elevated expression of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), the enzyme driving local GC activation, and GC signaling in osteoblasts, are associated with bone loss and obesity in HFD-fed male mice. Osteoblast-specific 11β-HSD1 knockout male mice exhibit resistance to HFD-induced bone loss and metabolic disorders. Mechanistically, elevated 11β-HSD1 restrains glucose uptake and osteogenic activity in osteoblast. Pharmacologically inhibiting osteoblastic 11β-HSD1 by using bone-targeted 11β-HSD1 inhibitor markedly promotes bone formation, ameliorates glucose handling and mitigated obesity in HFD-fed male mice. Taken together, our study demonstrates that osteoblastic 11β-HSD1 directly contributes to HFD-induced bone loss, glucose handling impairment and obesity.

High expression of L-GILZ transcript variant 1 (GILZ TV 1) is associated with increased 30-day sepsis mortality, and a high expression ratio possibly contraindicates hydrocortisone administration

BACKGROUND

Sepsis presents a challenge due to its complex immune responses, where balance between inflammation and anti-inflammation is critical for survival. Glucocorticoid-induced leucine zipper (GILZ) is key protein in achieving this balance, suppressing inflammation and mediating glucocorticoid response. This study aims to investigate GILZ transcript variants in sepsis patients and explore their potential for patient stratification and optimizing glucocorticoid therapy.

METHODS

Sepsis patients meeting the criteria outlined in Sepsis-3 were enrolled, and RNA was isolated from whole blood samples. Quantitative mRNA expression of GILZ transcript variants in both sepsis patient samples (n = 121) and the monocytic U937 cell line (n = 3), treated with hydrocortisone and lipopolysaccharides, was assessed using quantitative PCR (qPCR).

RESULTS

Elevated expression of GILZ transcript variant 1 (GILZ TV 1) serves as a marker for heightened 30-day mortality in septic patients. Increased levels of GILZ TV 1 within the initial day of sepsis onset are associated with a 2.2-[95% CI 1.2-4.3] fold rise in mortality, escalating to an 8.5-[95% CI 2.0-36.4] fold increase by day eight. GILZ TV1 expression is enhanced by glucocorticoids in cell culture but remains unaffected by inflammatory stimuli such as LPS. In septic patients, GILZ TV 1 expression increases over the course of sepsis and in response to hydrocortisone treatment. Furthermore, a high expression ratio of transcript variant 1 relative to all GILZ mRNA TVs correlates with a 2.3-fold higher mortality rate in patients receiving hydrocortisone treatment.

CONCLUSION

High expression of GILZ TV 1 is associated with a higher 30-day sepsis mortality rate. Moreover, a high expression ratio of GILZ TV 1 relative to all GILZ transcript variants is a parameter for identifying patient subgroups in which hydrocortisone may be contraindicated.

Glucocorticoid receptor action in prostate cancer: the role of transcription factor crosstalk

Prostate cancer is one of the most prevalent malignancies and is primarily driven by aberrant androgen receptor (AR) signaling. While AR-targeted therapies form the cornerstone of prostate cancer treatment, they often inadvertently activate compensatory pathways, leading to therapy resistance. This resistance is frequently mediated through changes in transcription factor (TF) crosstalk, reshaping gene regulatory programs and ultimately weakening treatment efficacy. Consequently, investigating TF interactions has become crucial for understanding the mechanisms driving therapy-resistant cancers. Recent evidence has highlighted the crosstalk between the glucocorticoid receptor (GR) and AR, demonstrating that GR can induce prostate cancer therapy resistance by replacing the inactivated AR, thereby becoming a driver of the disease. In addition to this oncogenic role, GR has also been shown to act as a tumor suppressor in prostate cancer. Owing to this dual role and the widespread use of glucocorticoids as adjuvant therapy, it is essential to understand GR's actions across different stages of prostate cancer development. In this review, we explore the current knowledge of GR in prostate cancer, with a specific focus on its crosstalk with other TFs. GR can directly and indirectly interact with a variety of TFs, and these interactions vary significantly depending on the type of prostate cancer cells. By highlighting these crosstalk interactions, we aim to provide insights that can guide the research and development of new GR-targeted therapies to mitigate its harmful effects in prostate cancer.

A TH17-intrinsic IL-1β-STAT5 axis drives steroid resistance in autoimmune neuroinflammation

Steroid resistance poses a major challenge for the management of autoimmune neuroinflammation. T helper 17 (TH17) cells are widely implicated in the pathology of steroid resistance; however, the underlying mechanisms are unknown. In this study, we identified that interleukin-1 receptor (IL-1R) blockade rendered experimental autoimmune encephalomyelitis (EAE) mice sensitive to dexamethasone (Dex) treatment. Interleukin-1β (IL-1β) induced a signal transducer and activator of transcription 5 (STAT5)-mediated steroid-resistant transcriptional program in TH17 cells, which promoted inflammatory cytokine production and suppressed Dex-induced anti-inflammatory genes. TH17-specific deletion of STAT5 ablated the IL-1β-induced steroid-resistant transcriptional program and rendered EAE mice sensitive to Dex treatment. IL-1β synergized with Dex to promote the STAT5-dependent expression of CD69 and the development of central nervous system (CNS)-resident CD69+ TH17 cells. Combined IL-1R blockade and Dex treatment ablated CNS-resident TH17 cells, reduced EAE severity, and prevented relapse. CD69+ tissue-resident TH17 cells were also detected in brain lesions of patients with multiple sclerosis. These findings (i) demonstrate that IL-1β-STAT5 signaling in TH17 cells mediates steroid resistance and (ii) identify a therapeutic strategy for reversing steroid resistance in TH17-mediated CNS autoimmunity.

Transcriptomics analysis of the bovine endometrium during the perioestrus period

During the oestrous cycle, the bovine endometrium undergoes morphological and functional changes, which are regulated by alterations in the levels of oestrogen and progesterone and consequent changes in gene expression. To clarify these changes before and after oestrus, RNA-seq was used to profile the transcriptome of oestrus-synchronized beef heifers. Endometrial samples were collected from 29 animals, which were slaughtered in six groups beginning 12 h after the withdrawal of intravaginal progesterone releasing devices until seven days post-oestrus onset (luteal phase). The groups represented proestrus, early oestrus, metoestrus and early dioestrus (luteal phase). Changes in gene expression were estimated relative to gene expression at oestrus. Ingenuity Pathway Analysis (IPA) was used to identify canonical pathways and functional processes of biological importance. A total of 5,845 differentially expressed genes (DEGs) were identified. The lowest number of DEGs was observed at the 12 h post-oestrus time point, whereas the greatest number was observed at Day 7 post-oestrus onset (luteal phase). A total of 2,748 DEGs at this time point did not overlap with any other time points. Prior to oestrus, Neurological disease and Organismal injury and abnormalities appeared among the top IPA diseases and functions categories, with upregulation of genes involved in neurogenesis. Lipid metabolism was upregulated before oestrus and downregulated at 48h post-oestrus, at which point an upregulation of immune-related pathways was observed. In contrast, in the luteal phase the Lipid metabolism and Small molecule biochemistry pathways were upregulated.

TSC22D3 as an immune-related prognostic biomarker for acute myeloid leukemia

Acute myeloid leukemia (AML) is the type of hematologic neoplasm most common in adults. Glucocorticoid-induced gene TSC22D3 regulates cell proliferation through its function as a transcription factor. However, there is no consensus on the prognostic and immunoregulatory significance of TSC22D3 in AML. In the present study, we evaluated the correlation between TSC22D3 expression, immunoinfiltration, and prognostic significance in AML. Knockdown of TSC22D3 significantly attenuated the proliferation of Hel cells and increased sensitivity to cytarabine (Ara-c) drugs. Furthermore, TSC22D3 reduced the release of interleukin-1β (IL-1β) by inhibiting the NF-κB/NLRP3 signaling pathway, thereby inhibiting macrophage polarization to M1 subtype, and attenuating the pro-inflammatory tumor microenvironment. In conclusion, this study identified TSC22D3 as an immune-related prognostic biomarker for AML patients and suggested that therapeutic targeting of TSC22D3 may be a potential treatment option for AML through tumor immune escape.

Systems Genomics Reveals microRNA Regulation of ICS Response in Childhood Asthma

BACKGROUND

Asthmatic patients' responses to inhaled corticosteroids (ICS) are variable and difficult to quantify. We have previously defined a Cross-sectional Asthma STEroid Response (CASTER) measure of ICS response. MicroRNAs (miRNAs) have shown strong effects on asthma and inflammatory processes.

OBJECTIVE

The purpose of this study was to identify key associations between circulating miRNAs and ICS response in childhood asthma.

METHODS

Small RNA sequencing in peripheral blood serum from 580 children with asthma on ICS treatment from The Genetics of Asthma in Costa Rica Study (GACRS) was used to identify miRNAs associated with ICS response using generalized linear models. Replication was conducted in children on ICS from the Childhood Asthma Management Program (CAMP) cohort. The association between replicated miRNAs and the transcriptome of lymphoblastoid cell lines in response to a glucocorticoid was assessed.

RESULTS

The association study on the GACRS cohort identified 36 miRNAs associated with ICS response at 10% false discovery rate (FDR), three of which (miR-28-5p, miR-339-3p, and miR-432-5p) were in the same direction of effect and significant in the CAMP replication cohort. In addition, in vitro steroid response lymphoblastoid gene expression analysis revealed 22 dexamethasone responsive genes were significantly associated with three replicated miRNAs. Furthermore, Weighted Gene Co-expression Network Analysis (WGCNA) revealed a significant association between miR-339-3p and two modules (black and magenta) of genes associated with immune response and inflammation pathways.

CONCLUSION

This study highlighted significant association between circulating miRNAs miR-28-5p, miR-339-3p, and miR-432-5p and ICS response. miR-339-3p may be involved in immune dysregulation, which leads to a poor response to ICS treatment.

Identification of actionable targets for breast cancer intervention using a diversity outbred mouse model

HER2-targeted therapy has improved breast cancer survival, but treatment resistance and disease prevention remain major challenges. Genes that enable HER2/Neu oncogenesis are the next intervention targets. A bioinformatics discovery platform of HER2/Neu-expressing Diversity Outbred (DO) F1 Mice was established to identify cancer-enabling genes. Quantitative Trait Loci (QTL) associated with onset ages and growth rates of spontaneous mammary tumors were sought. Twenty-six genes in 3 QTL contain sequence variations unique to the genetic backgrounds that are linked to aggressive tumors and 21 genes are associated with human breast cancer survival. Concurrent identification of TSC22D3, a transcription factor, and its target gene LILRB4, a myeloid cell checkpoint receptor, suggests an immune axis for regulation, or intervention, of disease. We also investigated TIEG1 gene that impedes tumor immunity but suppresses tumor growth. Although not an actionable target, TIEG1 study revealed genetic regulation of tumor progression, forming the basis of the genetics-based discovery platform.

Early growth response 2 in the mPFC regulates mouse social and cooperative behaviors

Adolescent social neglect impairs social performance, but the underlying molecular mechanisms remain unclear. Here we report that isolation rearing of juvenile mice caused cooperation defects that were rescued by immediate social reintroduction. We also identified the transcription factor early growth response 2 (Egr2) in the medial prefrontal cortex (mPFC) as a major target of social isolation and resocialization. Isolation rearing increased corticosteroid production, which reduced the expression of Egr2 in the mPFC, including in oligodendrocytes. Overexpressing Egr2 ubiquitously in the mPFC, but not specifically in neurons nor in oligodendroglia, protected mice from the isolation rearing-induced cooperation defect. In addition to synapse integrity, Egr2 also regulated the development of oligodendroglia, specifically the transition from undifferentiated oligodendrocyte precursor cells to premyelinating oligodendrocytes. In conclusion, this study reveals the importance of mPFC Egr2 in the cooperative behavior that is modulated by social experience, and its unexpected role in oligodendrocyte development.

Type 1 interferon suppresses expression and glucocorticoid induction of glucocorticoid-induced leucine zipper (GILZ)

SLE is a systemic multi-organ autoimmune condition associated with reduced life expectancy and quality of life. Glucocorticoids (GC) are heavily relied on for SLE treatment but are associated with detrimental metabolic effects. Type 1 interferons (IFN) are central to SLE pathogenesis and may confer GC insensitivity. Glucocorticoid-induced leucine zipper (GILZ) mediates many effects of GC relevant to SLE pathogenesis, but the effect of IFN on GC regulation of GILZ is unknown. We performed in vitro experiments using human PBMC to examine the effect of IFN on GILZ expression. JAK inhibitors tofacitinib and tosylate salt were used in vivo and in vitro respectively to investigate JAK-STAT pathway dependence of our observations. ChiP was performed to examine glucocorticoid receptor (GR) binding at the GILZ locus. Several public data sets were mined for correlating clinical data. High IFN was associated with suppressed GILZ and reduced GILZ relevant to GC exposure in a large SLE population. IFN directly reduced GILZ expression and suppressed the induction of GILZ by GC in vitro in human leukocytes. IFN actions on GILZ expression were dependent on the JAK1/Tyk2 pathway, as evidenced by loss of the inhibitory effect of IFN on GILZ in the presence of JAK inhibitors. Activation of this pathway led to reduced GR binding in key regulatory regions of the GILZ locus. IFN directly suppresses GILZ expression and GILZ upregulation by GC, indicating a potential mechanism for IFN-induced GC resistance. This work has important implications for the ongoing development of targeted GC-sparing therapeutics in SLE.

The contribution of the neuroendocrine system to adaption after repeated daily ozone exposure in rats

Ozone-induced lung injury/inflammation dissipates despite continued exposure for 3 or more days; however, the mechanisms of adaptation/habituation remain unclear. Since ozone effects are mediated through adrenal-derived stress hormones, which also regulate longevity of centrally-mediated stress response, we hypothesized that ozone-adaptation is linked to diminution of neuroendocrine stress-axes activation and glucocorticoid levels. Male Wistar-Kyoto-rats (12-week-old) were injected with vehicle or a therapeutically-relevant dexamethasone dose (0.01-mg/kg/day; intraperitoneal) for 1-month to determine if suppression of glucocorticoid signaling was linked to adaptation. Vehicle- and dexamethasone-treated rats were exposed to air or 0.8-ppm ozone, 4 h/day × 2 or 4 days to assess the impacts of acute exposure and adaptation, respectively. Dexamethasone reduced thymus and spleen weights, circulating lymphocytes, corticosterone and increased insulin. Ozone increased lavage-fluid protein and neutrophils and decreased circulating lymphocytes at day-2 but not day-4. Ozone-induced hyperglycemia, glucose intolerance and inhibition of beta-cell insulin release occurred at day-1 but not day-3. Ozone depleted circulating prolactin, thyroid-stimulating hormone, and luteinizing-hormone at day-2 but not day-4, suggesting central mediation of adaptation. Adrenal epinephrine biosynthesis gene, Pnmt, was up-regulated after ozone exposure at both timepoints. However, genes involved in glucocorticoid biosynthesis were up-regulated after day-2 but not day-4, suggesting that acute 1- or 2-day ozone-mediated glucocorticoid increase elicits feedback inhibition to dampen hypothalamic stimulation of ACTH release in response to repeated subsequent ozone exposures. Although dexamethasone pretreatment affected circulating insulin, lymphocytes and adrenal genes, it had modest effect on ozone adaptation. In conclusion, ozone adaptation likely involves lack of hypothalamic response due to reduced availability of circulating glucocorticoids.

GILZ regulates type I interferon release and sequesters STAT1

Glucocorticoids remain a mainstay of modern medicine due to their ability to broadly suppress immune activation. However, they cause severe adverse effects that warrant urgent development of a safer alternative. The glucocorticoid-induced leucine zipper (GILZ) gene, TSC22D3, is one of the most highly upregulated genes in response to glucocorticoid treatment, and reduced GILZ mRNA and protein levels are associated with increased severity of inflammation in systemic lupus erythematosus (SLE), Ulcerative Colitis, Psoriasis, and other autoimmune/autoinflammatory diseases. Here, we demonstrate that low GILZ permits expression of a type I interferon (IFN) signature, which is exacerbated in response to TLR7 and TLR9 stimulation. Conversely, overexpression of GILZ prevents IFN-stimulated gene (ISG) up-regulation in response to IFNα. Moreover, GILZ directly binds STAT1 and prevents its nuclear translocation, thereby negatively regulating IFN-induced gene expression and the auto-amplification loop of the IFN response. Thus, GILZ powerfully regulates both the expression and action of type I IFN, suggesting restoration of GILZ as an attractive therapeutic strategy for reducing reliance on glucocorticoids.

Advances on Innate Immune Evasion by Avian Immunosuppressive Viruses

Innate immunity is not only the first line of host defense against pathogenic infection, but also the cornerstone of adaptive immune response. Upon pathogenic infection, pattern recognition receptors (PRRs) of host engage pathogen-associated molecular patterns (PAMPs) of pathogens, which initiates IFN production by activating interferon regulatory transcription factors (IRFs), nuclear factor-kappa B (NF-κB), and/or activating protein-1 (AP-1) signal transduction pathways in host cells. In order to replicate and survive, pathogens have evolved multiple strategies to evade host innate immune responses, including IFN-I signal transduction, autophagy, apoptosis, necrosis, inflammasome and/or metabolic pathways. Some avian viruses may not be highly pathogenic but they have evolved varied strategies to evade or suppress host immune response for survival, causing huge impacts on the poultry industry worldwide. In this review, we focus on the advances on innate immune evasion by several important avian immunosuppressive viruses (infectious bursal disease virus (IBDV), Marek’s disease virus (MDV), avian leukosis virus (ALV), etc.), especially their evasion of PRRs-mediated signal transduction pathways (IFN-I signal transduction pathway) and IFNAR-JAK-STAT signal pathways. A comprehensive understanding of the mechanism by which avian viruses evade or suppress host immune responses will be of help to the development of novel vaccines and therapeutic reagents for the prevention and control of infectious diseases in chickens.

Triple combination of BET plus PI3K and NF-κB inhibitors exhibit synergistic activity in adult T cell leukemia/lymphoma

Triple combination of I-BET762, copanlisib, and bardoxolone methyl exhibits synergistic activity against ATL in vitro and in vivo.

Triple combination synergizes to inhibit c-MYC ex vivo in PBMCs containing leukemic cells from ATL patients.

Adult T-cell leukemia/lymphoma (ATL) is an aggressive T-cell lymphoproliferative malignancy caused by human T-cell leukemia virus type 1 (HTLV-1). ATL is an orphan disease with no curative drug treatment regimens urgently needing new combination therapy. HTLV-1-infected cells rely on viral proteins, Tax and HBZ (HTLV-1-b-ZIP factor), to activate the transcription of various host genes that are critical for promoting leukemic transformation. Inhibition of bromodomain and extraterminal motif (BET) protein was previously shown to collapse the transcriptional network directed by BATF3 super-enhancer and thereby induced ATL cell apoptosis. In the current work, by using xenograft, ex vivo, and in vitro models, we demonstrated that I-BET762 (BETi) synergized with copanlisib (PI3Ki) and bardoxolone methyl (NF-κBi) to dramatically decrease the growth of ATL cells. Mechanistically, the triple combination exhibited synergistic activity by down-regulating the expression of c-MYC while upregulating the level of the glucocorticoid-induced leucine zipper (GILZ). The triple combination also enhanced apoptosis induction by elevating the expression of active caspase-3 and cleaved PARP. Importantly, the triple combination prolonged the survival of ATL-bearing xenograft mice and inhibited the proliferation of ATL cells from peripheral blood mononuclear cells (PBMCs) of both acute and smoldering/chronic ATL patients. Therefore, our data provide the rationale for a clinical trial exploring the multiagent combination of BET, PI3K/AKT, and NF-κB inhibitors for ATL patients and expands the potential treatments for this recalcitrant malignancy.

Physiological Convergence and Antagonism Between GR and PPARγ in Inflammation and Metabolism

Nuclear receptors (NRs) are transcription factors that modulate gene expression in a ligand-dependent manner. The ubiquitously expressed glucocorticoid receptor (GR) and peroxisome proliferator-activated receptor gamma (PPARγ) represent steroid (type I) and non-steroid (type II) classes of NRs, respectively. The diverse transcriptional and physiological outcomes of their activation are highly tissue-specific. For example, in subsets of immune cells, such as macrophages, the signaling of GR and PPARγ converges to elicit an anti-inflammatory phenotype; in contrast, in the adipose tissue, their signaling can lead to reciprocal metabolic outcomes. This review explores the cooperative and divergent outcomes of GR and PPARγ functions in different cell types and tissues, including immune cells, adipose tissue and the liver. Understanding the coordinated control of these NR pathways should advance studies in the field and potentially pave the way for developing new therapeutic approaches to exploit the GR:PPARγ crosstalk.

SOCS3 Attenuates Dexamethasone-Induced M2 Polarization by Down-Regulation of GILZ via ROS- and p38 MAPK-Dependent Pathways

Suppressors of cytokine signaling (SOCS) have emerged as potential regulators of macrophage function. We have investigated mechanisms of SOCS3 action on type 2 macrophage (M2) differentiation induced by glucocorticoid using human monocytic cell lines and mouse bone marrow-derived macrophages. Treatment of THP1 monocytic cells with dexamethasone (Dex) induced ROS generation and M2 polarization promoting IL-10 and TGF-β production, while suppressing IL-1β, TNF-α and IL-6 production. SOCS3 over-expression reduced, whereas SOCS3 ablation enhanced IL-10 and TGF-β induction with concomitant regulation of ROS. As a mediator of M2 differentiation, glucocorticoid-induced leucine zipper (GILZ) was down-regulated by SOCS3 and up-regulated by shSOCS3. The induction of GILZ and IL-10 by Dex was dependent on ROS and p38 MAPK activity. Importantly, GILZ ablation led to the inhibition of ROS generation and anti-inflammatory cytokine induction by Dex. Moreover, GILZ knock-down negated the up-regulation of IL-10 production induced by shSOCS3 transduction. Our data suggest that SOCS3 targets ROS- and p38-dependent GILZ expression to suppress Dex-induced M2 polarization.

Glucocorticoid-Induced Leucine Zipper (GILZ) in Cardiovascular Health and Disease

Glucocorticoids (GCs) are essential in regulating functions and homeostasis in many biological systems and are extensively used to treat a variety of conditions associated with immune/inflammatory processes. GCs are among the most powerful drugs for the treatment of autoimmune and inflammatory diseases, but their long-term usage is limited by severe adverse effects. For this reason, to envision new therapies devoid of typical GC side effects, research has focused on expanding the knowledge of cellular and molecular effects of GCs. GC-induced leucine zipper (GILZ) is a GC-target protein shown to mediate several actions of GCs, including inhibition of the NF-κB and MAPK pathways. GILZ expression is not restricted to immune cells, and it has been shown to play a regulatory role in many organs and tissues, including the cardiovascular system. Research on the role of GILZ on endothelial cells has demonstrated its ability to modulate the inflammatory cascade, resulting in a downregulation of cytokines, chemokines, and cellular adhesion molecules. GILZ also has the capacity to protect myocardial cells, as its deletion makes the heart, after a deleterious stimulus, more susceptible to apoptosis, immune cell infiltration, hypertrophy, and impaired function. Despite these advances, we have only just begun to appreciate the relevance of GILZ in cardiovascular homeostasis and dysfunction. This review summarizes the current understanding of the role of GILZ in modulating biological processes relevant to cardiovascular biology.

Challenge of Bovine Foot Skin Fibroblasts With Digital Dermatitis Treponemes Identifies Distinct Pathogenic Mechanisms

Bovine digital dermatitis (BDD) is a common infectious disease of digital skin in cattle and an important cause of lameness worldwide, with limited treatment options. It is of increasing global concern for both animal welfare and food security, imposing a large economic burden on cattle farming industries each year. A polytreponemal etiology has been consistently identified, with three key phylogroups implicated globally: Treponema medium, Treponema phagedenis, and Treponema pedis. Pathogenic mechanisms which might enable targeted treatment/therapeutic development are poorly defined. This study used RNA sequencing to determine global differential mRNA expression in primary bovine foot skin fibroblasts following challenge with three representative BDD treponemes and a commensal treponeme, Treponema ruminis. A pro-inflammatory response was elicited by the BDD treponemes, mediated through IL-8/IL-17 signaling. Unexpectedly, the three BDD treponemes elicited distinct mechanisms of pathogenesis. T. phagedenis and T. pedis increased abundance of mRNA transcripts associated with apoptosis, while T. medium and T. pedis increased transcripts involved in actin rearrangement and loss of cell adhesion, likely promoting tissue invasion. The upregulation of antimicrobial peptide precursor, DEFB123, by T. phagedenis spirochaetes may present a microbial ecological advantage to all treponemes within BDD infected tissue, explaining their dominance within lesions. A commensal, T. ruminis, significantly dysregulated over three times the number of host mRNA transcripts compared to BDD treponemes, implying BDD treponemes, akin to the syphilis pathogen (Treponema pallidum), have evolved as "stealth pathogens" which avoid triggering substantial host immune/inflammatory responses to enable persistence and tissue invasion. Immunohistochemistry demonstrated increased IL-6, IL-8, RND1, and CFB protein expression in BDD lesions, confirming in vitro fibroblast observations and highlighting the system's value in modeling BDD pathogenesis. Several unique shared gene targets were identified, particularly RGS16, GRO1, MAFF, and ZC3H12A. The three key BDD Treponema phylogroups elicited both distinct and shared pathogenic mechanisms in bovine foot skin; upregulating inflammation whilst simultaneously suppressing adaptive immunity. The novel gene targets identified here should enable future vaccine/therapeutic approaches.

Artesunate protects immunosuppression mice induced by glucocorticoids via enhancing pro-inflammatory cytokines release and bacterial clearance

Glucocorticoids are commonly used in clinic, but the immunosuppression seriously hinders their usage. Herein, immunomodulatory effect of artesunate (AS) on hydrocortisone (HC)-induced immunosuppression was investigated. HC-induced immunosuppression mice (HC mice) were established by intramuscular administration with HC (20 mg/kg) once a day for 5 consecutive days. The results showed HC mice challenged with Escherichia coli on the sixth day presented a lower ability to clear bacteria, decreased TNF-α in blood, decreased spleen index and thymus index. Significantly, AS (20 mg/kg) treatment not only enhanced the ability of HC mice to clear bacteria, but also increased spleen index, the levels of pro-inflammatory cytokines from 78.7 ± 12.1 ng/ml (TNF-α) and 48.7 ± 8.6 pg/ml (IL-6) to 174.0 ± 90.5 ng/ml and 783.3 ± 90.5 pg/ml, number of white blood cells in blood, and sIgA in colon. Subsequently, HC-induced immunosuppression peritoneal macrophages model (HC cells) was established via addition of HC (0.5 μg/ml) for 0.5 h, and then LPS (100 ng/ml) was added to clarify the functional status of the cells. The results showed HC inhibited TNF-α and IL-6 mRNA expressions and their release, but AS (2.5 μg/ml) could increase TNF-α and IL-6 mRNA expressions and their release. AS inhibited GILZ mRNA up-regulated by HC and increases TLR4/NF-κB p65 expressions down-regulated by HC. Our findings revealed that AS's effect is closely related to the improvement of the TLR4/NF-κB signal transduction pathway via inhibiting the up-regulation of GILZ mRNA, demonstrating AS does possess immunomodulatory effects and is worth further investigation in the future.

Mechanisms and Clinical Applications of Glucocorticoid Steroids in Muscular Dystrophy

Glucocorticoid steroids are widely used as immunomodulatory agents in acute and chronic conditions. Glucocorticoid steroids such as prednisone and deflazacort are recommended for treating Duchenne Muscular Dystrophy where their use prolongs ambulation and life expectancy. Despite this benefit, glucocorticoid use in Duchenne Muscular Dystrophy is also associated with significant adverse consequences including adrenal suppression, growth impairment, poor bone health and metabolic syndrome. For other forms of muscular dystrophy like the limb girdle dystrophies, glucocorticoids are not typically used. Here we review the experimental evidence supporting multiple mechanisms of glucocorticoid action in dystrophic muscle including their role in dampening inflammation and myofiber injury. We also discuss alternative dosing strategies as well as novel steroid agents that are in development and testing, with the goal to reduce adverse consequences of prolonged glucocorticoid exposure while maximizing beneficial outcomes.

Glucocorticoids in T cell development, differentiation and function

Glucocorticoids (GCs) are small lipid hormones produced by the adrenals that maintain organismal homeostasis. Circadian and stress-induced changes in systemic GC levels regulate metabolism, cardiovascular and neural function, reproduction and immune activity. Our understanding of GC effects on immunity comes largely from administration of exogenous GCs to treat immune or inflammatory disorders. However, it is increasingly clear that endogenous GCs both promote and suppress T cell immunity. Examples include selecting an appropriate repertoire of T cell receptor (TCR) self-affinities in the thymus, regulating T cell trafficking between anatomical compartments, suppressing type 1 T helper (T_H1) cell responses while permitting T_H2 cell and, especially, IL-17-producing T helper cell responses, and promoting memory T cell differentiation and maintenance. Furthermore, in addition to functioning at a distance, extra-adrenal (local) production allows GCs to act as paracrine signals, specifically targeting activated T cells in various contexts in the thymus, mucosa and tumours. These pleiotropic effects on different T cell populations during development and immune responses provide a nuanced understanding of how GCs shape immunity.

Glucocorticoid-Induced Leucine Zipper as a Druggable Target in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders with a complex pathogenesis, affecting people of all ages. They are characterized by alternating phases of clinical relapse and remission, depending on the fine balance between immune cells and the gut microbiota. The cross talk between cells of the immune system and the gut microbiota can result in either tolerance or inflammation, according to multifactorial triggers, ranging from environmental factors to genetic susceptibility. Glucocorticoid (GC) administration remains the first-line treatment for IBDs, although long-term use is limited by development of serious adverse effects. Recently, new alternative pharmacological therapies have been developed, although these are not always effective in IBD patients. There is a constant demand for effective new drug targets to guarantee total remission and improve the quality of life for IBD patients. The glucocorticoid-induced leucine zipper (GILZ) has been implicated as a promising candidate for this purpose, in view of its powerful anti-inflammatory effects that mimic those of GCs while avoiding their unwanted adverse reactions. Here we present and discuss the latest findings about the involvement of GILZ in IBDs.

Anti-chicken type I IFN countermeasures by major avian RNA viruses

Chicken type I interferons (type I IFNs) are key antiviral players of the chicken innate immune system and are considered potent antiviral agents against avian viral pathogens. Chicken type I IFNs are divided into three subtypes namely, chIFN-α, chIFN-β, and chIFN-κ. Viral pathogen-associated molecular patterns (PAMPs) recognized by their corresponding specific PRRs (pattern recognition receptors) induce the expression of chicken type I IFNs. Interaction of chicken type I IFNs with their subsequent IFN receptors results in the activation of the JAK-STAT pathway, which in turn activates hundreds of chicken interferon-stimulated genes (chISGs). These chISGs establish an antiviral state in neighboring cells and prevent the replication and dissemination of viruses within chicken cells. Chicken type I IFNs activate different pathways that constitute major antiviral innate defense mechanisms in chickens. However, evolutionary mechanisms in viruses have made them resistant to these antiviral players by manipulating host innate immune pathways. This review focuses on the underlying molecular mechanisms employed by avian RNA viruses to counteract chicken type I IFNs and chISGs through different viral proteins. This may help to understand host-pathogen interactions and the development of novel therapeutic strategies to control viral infections in poultry.

Glucocorticoid-induced leucine zipper modulates macrophage polarization and apoptotic cell clearance

Macrophages are professional phagocytes that display remarkable plasticity, with a range of phenotypes that can be broadly characterized by the M1/M2 dichotomy. Glucocorticoid (GC)-induced leucine zipper (GILZ) is a protein known to mediate anti-inflammatory and some pro-resolving actions, including as neutrophil apoptosis. However, the role of GILZ in key macrophage function is not well understood. Here, we investigated the role of GILZ on macrophage reprogramming and efferocytosis. Using murine bone-marrow-derived macrophages (BMDMs), we found that GILZ was expressed in naive BMDMs and exhibited increased expression in M2-like macrophages (IL4-differentiated). M1-like macrophages (IFN/LPS-differentiated) from GILZ^-/- mice showed higher expression of the M1 markers CD86, MHC class II, iNOS, IL-6 and TNF-α, associated with increased levels of phosphorylated STAT1 and lower IL-10 levels, compared to M1-differentiated cells from WT mice. There were no changes in the M2 markers CD206 and arginase-1 in macrophages from GILZ^-/- mice differentiated with IL-4, compared to cells from WT animals. Treatment of M1-like macrophages with TAT-GILZ, a cell-permeable GILZ fusion protein, decreased the levels of CD86 and MHC class II in M1-like macrophages without modifying CD206 levels in M2-like macrophages. In line with the in vitro data, increased numbers of M1-like macrophages were found into the pleural cavity of GILZ^-/- mice after LPS-injection, compared to WT mice. Moreover, efferocytosis was defective in the context of GILZ deficiency, both in vitro and in vivo. Conversely, treatment of LPS-injected mice with TAT-GILZ promoted inflammation resolution, associated with lower numbers of M1-like macrophages and increased efferocytosis. Collectively, these data indicate that GILZ is a regulator of important macrophage functions, contributing to macrophage reprogramming and efferocytosis, both key steps for the resolution of inflammation.

Short-Chain Alcohols Upregulate GILZ Gene Expression and Attenuate LPS-Induced Septic Immune Response

Alcohol differentially affects human health, depending on the pattern of exposure. Moderate intake provides beneficial mood modulation and an anti-inflammatory effect, while excessive consumption leads to immunosuppression and various alcohol use disorders. The mechanism underlying this bi-phasic action mode of alcohol has not been clearly defined. Our previous publication demonstrated that ethanol, in the absence of glucocorticoids (GCs), induces expression of Glucocorticoid-Induced Leucine Zipper (GILZ), a key molecule that transduces GC anti-inflammatory effect through a non-canonical activation of glucocorticoid receptor (1). Here we report that similar short-chain alcohols, such as ethanol, propanol and isopropanol, share the same property of upregulating GILZ gene expression, and blunt cell inflammatory response in vitro. When mice were exposed to these alcohols, GILZ gene expression in immune cells was augmented in a dose-dependent manner. Monocytes and neutrophils were most affected. The short-chain alcohols suppressed host inflammatory response to lipopolysaccharide (LPS) and significantly reduced LPS-induced mortality. Intriguingly, propanol and isopropanol displayed more potent protection than ethanol at the same dose. Inhibition of ethanol metabolism enhanced the ethanol protective effect, suggesting that it is ethanol, not its derivatives or metabolites, that induces immune suppression. Taken together, short-chain alcohols per se upregulate GILZ gene expression and provide immune protection against LPS toxicity, suggesting a potential measure to counter LPS septic shock in a resource limited situation.

Implicating the Role of GILZ in Glucocorticoid Modulation of T-Cell Activation

Glucocorticoid-induced leucine zipper (GILZ) is a protein with multiple biological roles that is upregulated by glucocorticoids (GCs) in both immune and non-immune cells. Importantly, GCs are immunosuppressive primarily due to their regulation of cell signaling pathways that are crucial for immune system activity. GILZ, which is transcriptionally induced by the glucocorticoid receptor (GR), mediates part of these immunosuppressive, and anti-inflammatory effects, thereby controlling immune cell proliferation, survival, and differentiation. The primary immune cells targeted by the immunosuppressive activity of GCs are T cells. Importantly, the effects of GCs on T cells are partially mediated by GILZ. In fact, GILZ regulates T-cell activation, and differentiation by binding and inhibiting factors essential for T-cell function. For example, GILZ associates with nuclear factor-κB (NF-κB), c-Fos, and c-Jun and inhibits NF-κB-, and AP-1-dependent transcription. GILZ also binds Raf and Ras, inhibits activation of Ras/Raf downstream targets, including mitogen-activated protein kinase 1 (MAPK1). In addition GILZ inhibits forkhead box O3 (FoxO3) without physical interaction. GILZ also promotes the activity of regulatory T cells (Tregs) by activating transforming growth factor-β (TGF-β) signaling. Ultimately, these actions inhibit T-cell activation and modulate the differentiation of T helper (Th)-1, Th-2, Th-17 cells, thereby mediating the immunosuppressive effects of GCs on T cells. In this mini-review, we discuss how GILZ mediates GC activity on T cells, focusing mainly on the therapeutic potential of this protein as a more targeted anti-inflammatory/immunosuppressive GC therapy.

Could GILZ Be the Answer to Glucocorticoid Toxicity in Lupus?

Glucocorticoids (GC) are used globally to treat autoimmune and inflammatory disorders. Their anti-inflammatory actions are mainly mediated via binding to the glucocorticoid receptor (GR), creating a GC/GR complex, which acts in both the cytoplasm and nucleus to regulate the transcription of a host of target genes. As a result, signaling pathways such as NF-κB and AP-1 are inhibited, and cell activation, differentiation and survival and cytokine and chemokine production are suppressed. However, the gene regulation by GC can also cause severe side effects in patients. Systemic lupus erythematosus (SLE or lupus) is a multisystem autoimmune disease, characterized by a poorly regulated immune response leading to chronic inflammation and dysfunction of multiple organs, for which GC is the major current therapy. Long-term GC use, however, can cause debilitating adverse consequences for patients including diabetes, cardiovascular disease and osteoporosis and contributes to irreversible organ damage. To date, there is no alternative treatment which can replicate the rapid effects of GC across multiple immune cell functions, effecting disease control during disease flares. Research efforts have focused on finding alternatives to GC, which display similar immunoregulatory actions, without the devastating adverse metabolic effects. One potential candidate is the glucocorticoid-induced leucine zipper (GILZ). GILZ is induced by low concentrations of GC and is shown to mimic the action of GC in several inflammatory processes, reducing immunity and inflammation in in vitro and in vivo studies. Additionally, GILZ has, similar to the GC-GR complex, the ability to bind to both NF-κB and AP-1 as well as DNA directly, to regulate immune cell function, while potentially lacking the GC-related side effects. Importantly, in SLE patients GILZ is under-expressed and correlates negatively with disease activity, suggesting an important regulatory role of GILZ in SLE. Here we provide an overview of the actions and use of GC in lupus, and discuss whether the regulatory mechanisms of GILZ could lead to the development of a novel therapeutic for lupus. Increased understanding of the mechanisms of action of GILZ, and its ability to regulate immune events leading to lupus disease activity has important clinical implications for the development of safer anti-inflammatory therapies.

Glucocorticoid-Induced Leucine Zipper: A Novel Anti-inflammatory Molecule

Glucocorticoids (GCs) are the most commonly used drugs for treatment of autoimmune and inflammatory diseases. Their efficacy is due to their ability to bind cytoplasmic receptors (glucocorticoid receptors, GR) and other cytoplasmic proteins, thus regulating gene expression. Although GCs are potent life-saving drugs, their therapeutic effects are transitory and chronic use of GCs is accompanied by serious side effects. Therefore, new drugs are needed to replace GCs. We have identified a gene, glucocorticoid-induced leucine zipper (GILZ or tsc22d3), that is rapidly and invariably induced by GCs. Human GILZ is a 135-amino acid protein that mediates many GC effects, including inhibition of the NF-κB and MAPK pathways. Similar to GCs, GILZ exerts anti-inflammatory activity in experimental disease models, including inflammatory bowel diseases and arthritis. While transgenic mice that overexpress GILZ are more resistant, GILZ knockout mice develop worse inflammatory diseases. Moreover, the anti-inflammatory effect of GCs is attenuated in GILZ-deficient mice. Importantly, in vivo delivery of recombinant GILZ protein cured colitis and facilitated resolution of lipopolysaccharide-induced inflammation without apparent toxic effects. A synthetic GILZ-derived peptide, corresponding to the GILZ region that interacts with NF-κB, was able to suppress experimental autoimmune encephalomyelitis. Collectively, these findings indicate that GILZ is an anti-inflammatory molecule that may serve as the basis for designing new therapeutic approaches to inflammatory diseases.

Context-Dependent Effect of Glucocorticoids on the Proliferation, Differentiation, and Apoptosis of Regulatory T Cells: A Review of the Empirical Evidence and Clinical Applications

Glucocorticoids (GCs) are widely used to treat several diseases because of their powerful anti-inflammatory and immunomodulatory effects on immune cells and non-lymphoid tissues. The effects of GCs on T cells are the most relevant in this regard. In this review, we analyze how GCs modulate the survival, maturation, and differentiation of regulatory T (Treg) cell subsets into both murine models and humans. In this way, GCs change the Treg cell number with an impact on the mid-term and long-term efficacy of GC treatment. In vitro studies suggest that the GC-dependent expansion of Treg cells is relevant when they are activated. In agreement with this observation, the GC treatment of patients with established autoimmune, allergic, or (auto)inflammatory diseases causes an expansion of Treg cells. An exception to this appears to be the local GC treatment of psoriatic lesions. Moreover, the effects on Treg number in patients with multiple sclerosis are uncertain. The effects of GCs on Treg cell number in healthy/diseased subjects treated with or exposed to allergens/antigens appear to be context-dependent. Considering the relevance of this effect in the maturation of the immune system (tolerogenic response to antigens), the success of vaccination (including desensitization), and the tolerance to xenografts, the findings must be considered when planning GC treatment.

Amplified Host Defense by Toll-Like Receptor-Mediated Downregulation of the Glucocorticoid-Induced Leucine Zipper (GILZ) in Macrophages

Activation of toll-like receptors (TLRs) plays a pivotal role in the host defense against bacteria and results in the activation of NF-κB-mediated transcription of proinflammatory mediators. Glucocorticoid-induced leucine zipper (GILZ) is an anti-inflammatory mediator, which inhibits NF-κB activity in macrophages. Thus, we aimed to investigate the regulation and role of GILZ expression in primary human and murine macrophages upon TLR activation. Treatment with TLR agonists, e.g., Pam₃CSK₄ (TLR1/2) or LPS (TLR4) rapidly decreased GILZ mRNA and protein levels. In consequence, GILZ downregulation led to enhanced induction of pro-inflammatory mediators, increased phagocytic activity, and a higher capacity to kill intracellular bacteria (Salmonella enterica serovar typhimurium), as shown in GILZ knockout macrophages. Treatment with the TLR3 ligand polyinosinic: polycytidylic acid [Poly(I:C)] did not affect GILZ mRNA levels, although GILZ protein expression was decreased. This effect was paralleled by sensitization toward TLR1/2- and TLR4-agonists. A bioinformatics approach implicated more than 250 miRNAs as potential GILZ regulators. Microarray analysis revealed that the expression of several potentially GILZ-targeting miRNAs was increased after Poly(I:C) treatment in primary human macrophages. We tested the ability of 11 of these miRNAs to target GILZ by luciferase reporter gene assays. Within this small set, four miRNAs (hsa-miR-34b^*,−222,−320d,−484) were confirmed as GILZ regulators, suggesting that GILZ downregulation upon TLR3 activation is a consequence of the synergistic actions of multiple miRNAs. In summary, our data show that GILZ downregulation promotes macrophage activation. GILZ downregulation occurs both via MyD88-dependent and -independent mechanisms and can involve decreased mRNA or protein stability and an attenuated translation.

MUC1 deficiency mediates corticosteroid resistance in chronic obstructive pulmonary disease

Background

Lung inflammation in COPD is poorly controlled by inhaled corticosteroids (ICS). Strategies to improve ICS efficacy or the search of biomarkers who may select those patients candidates to receive ICS in COPD are needed. Recent data indicate that MUC1 cytoplasmic tail (CT) membrane mucin can mediate corticosteroid efficacy in chronic rhinosinusitis. The objective of this work was to analyze the previously unexplored role of MUC1 on corticosteroid efficacy in COPD in vitro and in vivo models.

Methods

MUC1-CT expression was measured by real time PCR, western blot, immunohistochemistry and immunofluorescence. The inflammatory mediators IL-8, MMP9, GM-CSF and MIP3α were measured by ELISA. The effect of MUC1 on inflammation and corticosteroid anti-inflammatory effects was measured using cell siRNA in vitro and Muc1-KO in vivo animal models.

Results

MUC1-CT expression was downregulated in lung tissue, bronchial epithelial cells and lung neutrophils from smokers (n = 11) and COPD (n = 11) patients compared with healthy subjects (n = 10). MUC1 was correlated with FEV1% (ρ = 0.7479; p < 0.0001) in smokers and COPD patients. Cigarette smoke extract (CSE) decreased the expression of MUC1 and induced corticosteroid resistance in human primary bronchial epithelial cells and human neutrophils. MUC1 Gene silencing using siRNA-MUC1 impaired the anti-inflammatory effects of dexamethasone and reduced glucocorticoid response element activation. Dexamethasone promoted glucocorticoid receptor alpha (GRα) and MUC1-CT nuclear translocation and co-localization that was inhibited by CSE. Lung function decline and inflammation induced by lipopolysaccharide and cigarette smoke in Muc1 KO mice was resistant to dexamethasone.

Conclusions

These results confirm a role for MUC1-CT mediating corticosteroid efficacy in COPD.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0927-4) contains supplementary material, which is available to authorized users.

Increasing G9a automethylation sensitizes B acute lymphoblastic leukemia cells to glucocorticoid-induced death

Synthetic glucocorticoids (GCs) are used to treat lymphoid cancers, but many patients develop resistance to treatment, especially to GC. By identifying genes that influence sensitivity to GC-induced cell death, we found that histone methyltransferases G9a and G9a-like protein (GLP), two glucocorticoid receptor (GR) coactivators, are required for GC-induced cell death in acute lymphoblastic leukemia (B-ALL) cell line Nalm6. We previously established in a few selected genes that automethylated G9a and GLP recruit heterochromatin protein 1γ (HP1γ) as another required coactivator. Here, we used a genome-wide analysis to show that HP1γ is selectively required for GC-regulated expression of the great majority of GR target genes that require G9a and GLP. To further address the importance of G9a and GLP methylation in this process and in cell physiology, we found that JIB-04, a selective JmjC family lysine demethylase inhibitor, increased G9a methylation and thereby increased G9a binding to HP1γ. This led to increased expression of GR target genes regulated by G9a, GLP and HP1γ and enhanced Nalm6 cell death. Finally, the KDM4 lysine demethylase subfamily demethylates G9a in vitro, in contrast to other KDM enzymes tested. Thus, inhibiting G9a/GLP demethylation potentially represents a novel method to restore sensitivity of treatment-resistant B-ALL tumors to GC-induced cell death.

Effect of preoperative inhaled budesonide on pulmonary injury after cardiopulmonary bypass: A randomized pilot study

BACKGROUND

Cardiopulmonary bypass can result in lung injury. This prospective, double-blinded, randomized trial aimed to evaluate the protective effect of inhaled budesonide on lung injury after cardiopulmonary bypass.

METHODS

Sixty patients, aged 25 to 65 years, requiring cardiopulmonary bypass were randomized to groups treated with saline or budesonide inhalation preoperatively. The respiratory mechanics were recorded. Bronchoalveolar lavage fluid was collected before cardiopulmonary bypass and after sternal closure. Serum and bronchoalveolar lavage fluid levels of proinflammatory and anti-inflammatory factors were analyzed. The primary end point was the lowest ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen after cardiopulmonary bypass. The durations of ventilation and postoperative recovery time were noted.

RESULTS

Budesonide significantly improved respiratory mechanics after cardiopulmonary bypass. Budesonide improved the partial pressure of arterial oxygen to the fraction of inspired oxygen ratio from 8 to 48 hours after the operation. Budesonide shortened the durations of mechanical ventilation and postoperative recovery time. Budesonide decreased the levels of proinflammatory factors while increasing the levels of anti-inflammatory factors in bronchoalveolar lavage fluid and serum (all P < .05). The macrophage and neutrophil counts, and protein and elastase concentrations were decreased by budesonide treatment.

CONCLUSIONS

Budesonide treatment shortened the durations of mechanical ventilation, inhibited local and systemic inflammation, and improved respiratory function after cardiopulmonary bypass.

Air pollution and resistance to inhaled glucocorticoids: Evidence, mechanisms and gaps to fill

Substantial evidence indicates that cigarette smoke exposure induces resistance to glucocorticoids, the primary maintenance medication in asthma treatment. Modest evidence also suggests that air pollution may reduce the effectiveness of these critical medications. Cigarette smoke, which has clear parallels with air pollution, has been shown to induce glucocorticoid resistance in asthma and it has been speculated that air pollution may have similar effects. However, the literature on an association of air pollution with glucocorticoid resistance is modest to date. In this review, we detail the evidence for, and against, the effects of air pollution on glucocorticoid effectiveness, focusing on results from epidemiology and controlled human exposure studies. Epidemiological studies indicate a correlation between increased air pollution exposure and worse asthma symptoms. But these studies also show a mix of beneficial and harmful effects of glucocorticoids on spirometry and asthma symptoms, perhaps due to confounding influences, or the induction of glucocorticoid resistance. We describe mechanisms that may contribute to reductions in glucocorticoid responsiveness following air pollution exposure, including changes to phosphorylation or oxidation of the glucocorticoid receptor, repression by cytokines, or inflammatory pathways, and epigenetic effects. Possible interactions between air pollution and respiratory infections are also briefly discussed. Finally, we detail a number of therapies that may boost glucocorticoid effectiveness or reverse resistance in the presence of air pollution, and comment on the beneficial effects of engineering controls, such as air filtration and asthma action plans. We also call attention to the benefits of improved clean air policy on asthma. This review highlights numerous gaps in our knowledge of the interactions between air pollution and glucocorticoids to encourage further research in this area with a view to reducing the harm caused to those with airways disease.

Defining the role of glucocorticoids in inflammation

An established body of knowledge and clinical practice has argued in favor of the use of glucocorticoids in various chronic inflammatory and autoimmune diseases. However, the very well-known adverse effects associated with their treatment hampers continuation of therapy with glucocorticoids. Analyses of the molecular mechanisms underlying the actions of glucocorticoids have led to the discovery of several mediators that add complexity and diversity to the puzzling world of these hormones and anti-inflammatory drugs. Such mediators hold great promise as alternative pharmacologic tools to be used as anti-inflammatory drugs with the same properties as glucocorticoids, but avoiding their metabolic side effects. This review summarizes findings about the molecular targets and mediators of glucocorticoid function.

Glucocorticoid-Induced Leucine Zipper Inhibits Interferon-Gamma Production in B Cells and Suppresses Colitis in Mice

Glucocorticoid-induced leucine zipper (GILZ) is transcriptionally upregulated by glucocorticoids (GCs) and mediates many of the anti-inflammatory effects of GCs. Since B cell activity has been linked to cytokine production and modulation of inflammatory responses, we herein investigated the role of GILZ in B cells during colitis development. B cell-specific gilz knock-out (gilz B cKO) mice exhibited increased production of the pro-inflammatory cytokine IFN-γ in B cells, and consequently CD4⁺ T cell activation. Increased IFN-γ production in B cells was associated with enhanced transcriptional activity of the transcription factor activator protein-1 (AP-1) on the IFN-γ promoter. Moreover, GILZ deficiency in B cells was linked to enhanced susceptibility to experimental colitis in mice, and this was reversed by administering GILZ protein. Interestingly, we observed increased production of IFN-γ in both B and T cells infiltrating the lamina propria (LP) of gilz B cKO mice. Together, these findings indicate that GILZ controls IFN-γ production in B cells, which also affects T cell activity, and increased production of IFN-γ by B and T cells in LP is associated with predisposition to inflammatory colitis in mice.

Glucocorticoid-Induced Leucine Zipper: Fine-Tuning of Dendritic Cells Function

Dendritic cells (DCs) are key antigen-presenting cells that control the induction of both tolerance and immunity. Understanding the molecular mechanisms regulating DCs commitment toward a regulatory- or effector-inducing profile is critical for better designing prophylactic and therapeutic approaches. Initially identified in dexamethasone-treated thymocytes, the glucocorticoid-induced leucine zipper (GILZ) protein has emerged as a critical factor mediating most, but not all, glucocorticoids effects in both non-immune and immune cells. This intracellular protein exerts pleiotropic effects through interactions with transcription factors and signaling proteins, thus modulating signal transduction and gene expression. GILZ has been reported to control the proliferation, survival, and differentiation of lymphocytes, while its expression confers anti-inflammatory phenotype to monocytes and macrophages. In the past twelve years, a growing set of data has also established that GILZ expression in DCs is a molecular switch controlling their T-cell-priming capacity. Here, after a brief presentation of GILZ isoforms and functions, we summarize current knowledge regarding GILZ expression and regulation in DCs, in both health and disease. We further present the functional consequences of GILZ expression on DCs capacity to prime effector or regulatory T-cell responses and highlight recent findings pointing to a broader role of GILZ in the fine tuning of antigen capture, processing, and presentation by DCs. Finally, we discuss future prospects regarding the possible roles for GILZ in the control of DCs function in the steady state and in the context of infections and chronic pathologies.

Establishment of a Monoclonal Antibody Against chGILZ

The chicken glucocorticoid-induced leucine zipper (chGILZ) participates in the inflammation of avian immunosuppressive diseases. We aimed to establish a monoclonal antibody (MAb) against chGILZ and to investigate its distribution in clinical diagnosis. A gene cloned from chicken embryo fibroblast (CEF) cell was inserted into the expression vector pET-28a and pGEX-6p-1. The recombinant expression vectors were transformed into Escherichia coli BL21 (DE3). Then the recombinant proteins His-chGILZ and GST-chGILZ were successfully expressed and purified. The hybridomas were developed by fusing mouse myeloma cell line SP2/0 with splenocytes of immunized mice and screened with purified GST-chGILZ. Two hybridomas (1D3 and 3F4) were effective in detecting both recombinant and native chGILZ proteins and were isolated and characterized. The MAbs did not react with human GILZ protein, but could recognize chGILZ by Western blot assay. These data and reagents will be of great assistance to elucidate the molecular mechanism of avian immunosuppressive diseases, such as the infectious bursal disease.

A dual role for glucocorticoid-induced leucine zipper in glucocorticoid function: tumor growth promotion or suppression?

Glucocorticoids (GCs), important therapeutic tools to treat inflammatory and immunosuppressive diseases, can also be used as part of cancer therapy. In oncology, GCs are used as anticancer drugs for lymphohematopoietic malignancies, while in solid neoplasms primarily to control the side effects of chemo/radiotherapy treatments. The molecular mechanisms underlying the effects of GCs are numerous and often overlapping, but not all have been elucidated. In normal, cancerous, and inflammatory tissues, the response to GCs differs based on the tissue type. The effects of GCs are dependent on several factors: the tumor type, the GC therapy being used, the expression level of the glucocorticoid receptor (GR), and the presence of any other stimuli such as signals from immune cells and the tumor microenvironment. Therefore, GCs may either promote or suppress tumor growth via different molecular mechanisms. Stress exposure results in dysregulation of the hypothalamic-pituitary-adrenal axis with increased levels of endogenous GCs that promote tumorigenesis, confirming the importance of GCs in tumor growth. Most of the effects of GCs are genomic and mediated by the modulation of GR gene transcription. Moreover, among the GR-induced genes, glucocorticoid-induced leucine zipper (GILZ), which was cloned and characterized primarily in our laboratory, mediates many GC anti-inflammatory effects. In this review, we analyzed the possible role for GILZ in the effects GCs have on tumors cells. We also suggest that GILZ, by affecting the immune system, tumor microenvironment, and directly cancer cell biology, has a tumor-promoting function. However, it may also induce apoptosis or decrease the proliferation of cancer cells, thus inhibiting tumor growth. The potential therapeutic implications of GILZ activity on tumor cells are discussed here.

Xihuang pill promotes apoptosis of Treg cells in the tumor microenvironment in 4T1 mouse breast cancer by upregulating MEKK1/SEK1/JNK1/AP-1 pathway

OBJECTIVE

To determine the role of the MEKK1/SEK1/JNK1/AP-1 pathway in the action of Xihuang pill (XHP) in reducing regulatory T (Treg) cell numbers in the tumor microenvironment in a 4T1 mouse breast cancer model, and to clarify the anti-tumor mechanism of XHP in breast cancer.

METHODS

We established a mouse 4T1 breast cancer model. Model mice were administered XHP for 2 weeks, and tumor tissues were then removed, weighed, sliced, and homogenized. Treg cells in the tumor microenvironment were isolated by magnetic cell sorting and analyzed by immunohistochemistry and flow cytometry. Treg cell apoptosis was detected by TdT-mediated dUTP nick end labeling. mRNA expression levels of MEKK1, SEK1, JNK1, and AP-1 in Treg cells in the tumor microenvironment were detected by quantitative real-time PCR and their protein expression levels were detected by immunofluorescence staining and western blot.

RESULTS

Tumor weights were significantly lower in the XHP groups compared with the untreated control group. The overall number of Treg cells in the tumor microenvironment decreased while the number of apoptotic Treg cells increased with increasing doses of XHP. mRNA and protein expression levels of MEKK1, SEK1, JNK1, and AP-1 in Treg cells in the tumor microenvironment increased with increasing doses of XHP.

CONCLUSION

XHP might promote Treg cell apoptosis in the tumor microenvironment and further inhibit the tumor growth of 4T1 mouse breast cancer. The mechanism of XHP may be related to upregulation of gene and protein expression of MEKK1, SEK1, JNK1, and AP-1 in Treg cells in the tumor microenvironment.

RNA sequencing reveals widespread transcriptome changes in a renal carcinoma cell line

We used RNA sequencing (RNA-Seq) technology to investigate changes in the transcriptome profile in the Caki-1 clear cell renal cell carcinoma (ccRCC) cells, which overexpress monocyte chemoattractant protein-induced protein 1 (MCPIP1). RNA-Seq data showed changes in 11.6% and 41.8% of the global transcriptome of Caki-1 cells overexpressing wild-type MCPIP1 or its D141N mutant, respectively. Gene ontology and KEGG pathway functional analyses showed that these transcripts encoded proteins involved in cell cycle progression, protein folding in the endoplasmic reticulum, hypoxia response and cell signalling. We identified 219 downregulated transcripts in MCPIP1-expressing cells that were either unchanged or upregulated in D141N-expressing cells. We validated downregulation of 15 transcripts belonging to different functional pathways by qRT-PCR. The growth and viability of MCPIP1-expressing cells was reduced because of elevated p21Cip1 levels. MCPIP1-expressing cells also showed reduced levels of DDB1 transcript that encodes component of the E3 ubiquitin ligase that degrades p21Cip1. These results demonstrate that MCPIP1 influences the growth and viability of ccRCC cells by increasing or decreasing the transcript levels for proteins involved in cell cycle progression, protein folding, hypoxia response, and cell signaling.

Oxidative stress and cellular pathways of asthma and inflammation: Therapeutic strategies and pharmacological targets

Asthma is a complex inflammatory disease characterized by airway inflammation and hyperresponsiveness. The mechanisms associated with the development and progression of asthma have been widely studied in multiple populations and animal models, and these have revealed involvement of various cell types and activation of intracellular signaling pathways that result in activation of inflammatory genes. Significant contributions of Toll-like-receptors (TLRs) and transcription factors such as NF-кB, have been reported as major contributors to inflammatory pathways. These have also recently been associated with mechanisms of oxidative biology. This is of important clinical significance as the observed inefficacy of current available treatments for severe asthma is widely attributed to oxidative stress. Therefore, targeting oxidizing molecules in conjunction with inflammatory mediators and transcription factors may present a novel therapeutic strategy for asthma. In this review, we summarize TLRs and NF-кB pathways in the context of exacerbation of asthma pathogenesis and oxidative biology, and we discuss the potential use of polyphenolic flavonoid compounds, known to target these pathways and possess antioxidant activity, as potential therapeutic agents for asthma.

Budesonide instillation immediately after reperfusion ameliorates ischemia/reperfusion-induced injury in the transplanted lung of rat

PURPOSE

Lung ischemia-reperfusion injury (LIRI) after lung transplantation can lead to primary graft dysfunction. Budesonide can improve endothelial function to reduce lung injury. This study was aimed to examine the effects of budesonide on LIRI and potential mechanisms.

METHODS

Wistar rats were randomized and transplanted with syngeneic left lung or received the sham surgery. The recipients were instilled with saline or budesonide immediately after reperfusion. The mean arterial pressure (MAP), blood gas, and lung histology were analyzed. The ratios of wet to dry lung weights, the levels of total proteins, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10, and neutrophil elastase in bronchoalveolar lavage fluid (BALF) were measured. The levels of malondialdehyde (MDA), myeloperoxidase (MPO), and xanthine oxidase (XO) in the lung, and the levels of plasma lymphocyte function-associated antigen (LFA)-1 and P-selectin were determined.

RESULTS

Compared with the saline group, treatment with budesonide significantly increased blood PaO₂, but reduced PaCO₂, and mitigated lung damages after reperfusion, the levels of BALF proteins, and the ratios of wet to dry lung weights in rats. Furthermore, treatment with budesonide significantly decreased the levels of MDA, MPO, and XO in the lung and the levels of TNF-α, IL-1β, IL-6, and neutrophil elastase, but increased IL-10 in the BALF, accompanied by significantly reduced levels of serum P-selectin and LFA-1 in rats.

CONCLUSIONS

Budesonide effectively mitigated LIRI and ameliorated the lung function by attenuating oxidative stress and inflammation following syngeneic lung transplantation.