Dexamethasone reduces IL-17 and Tim-3 expression in BALF of asthmatic mice

Soluble TIM-3 as a biomarker of progression and therapeutic response in cancers and other of human diseases

Immune checkpoints inhibition is a privileged approach to combat cancers and other human diseases. The TIM-3 (T cell immunoglobulin and mucin-domain containing-3) inhibitory checkpoint expressed on different types of immune cells is actively investigated as an anticancer target, with a dozen of monoclonal antibodies in (pre)clinical development. A soluble form sTIM-3 can be found in the plasma of patients with cancer and other diseases. This active circulating protein originates from the proteolytic cleavage by two ADAM metalloproteases of the membrane receptor shared by tumor and non-tumor cells, and extracellular vesicles. In most cancers but not all, overexpression of mTIM-3 at the cell surface leads to high level of sTIM-3. Similarly, elevated levels of sTIM-3 have been reported in chronic autoimmune diseases, inflammatory gastro-intestinal diseases, certain viral and parasitic diseases, but also in cases of organ transplantation and in pregnancy-related pathologies. We have analyzed the origin of sTIM-3, its methods of dosage in blood or plasma, its presence in multiple diseases and its potential role as a biomarker to follow disease progression and/or the treatment response. In contrast to sPD-L1 generated by different classes of proteases and by alternative splicing, sTIM-3 is uniquely produced upon ADAM-dependent shedding, providing a more homogenous molecular entity and a possibly more reliable molecular marker. However, the biological functionality of sTIM-3 remains insufficiently characterized. The review shed light on pathologies associated with an altered expression of sTIM-3 in human plasma and the possibility to use sTIM-3 as a diagnostic or therapeutic marker.

GLCCI1 Deficiency Induces Glucocorticoid Resistance via the Competitive Binding of IRF1:GRIP1 and IRF3:GRIP1 in Asthma

GLCCI1 plays a significant role in modulating glucocorticoid (GC) sensitivity in asthma. This project determines the underlying mechanism that GLCCI1 deficiency attenuates GC sensitivity in dexamethasone (Dex)-treated Ovalbumin (OVA)-induced asthma mice and epithelial cells through upregulating binding of IRF1:GRIP1 and IRF3:GRIP1. Dexamethasone treatment led to less reduced inflammation, airway hyperresponsiveness, and activation of the components responsible for GC activity, as determined by decreased GR and glucocorticoid receptor interacting protein 1 (GRIP1) expression but augmented IRF1 and IRF3 expression in GLCCI1^−/− asthmatic mice compared with wild type asthmatic mice. Moreover, the recruitment of GRIP1 to GR was downregulated, while the individual recruitment of GRIP1 to IRF1 and IRF3 was upregulated in GLCCI1^−/− Dex-treated asthmatic mice compared to wild type Dex-treated asthmatic mice. We also found that GLCCI1 knockdown reduced GR and GRIP1 expression but increased IRF1 and IRF3 expression in Beas2B and A549 cells. Additionally, GLCCI1 silencing increased the interactions between GRIP1 with IRF1 and GRIP1 with IRF3, but decreased the recruitment of GRIP1 to GR. These studies support a critical but previously unrecognized effect of GLCCI1 expression on epithelial cells in asthma GC responses by which GLCCI1 deficiency reduces the GR and GRIP1 interaction but competitively enhances the recruitment of GRIP1 to IRF1 and IRF3.

Preventive and therapeutic effect of anti-IL-17 in an experimental model of elastase-induced lung injury in C57Bl6 mice

Chronic obstructive pulmonary disease (COPD) is an important health care issue, and IL-17 can modulate inflammatory responses. We evaluated preventive and therapeutic effect of anti-interleukin (IL)-17 in a model of lung injury induced by elastase, using 32 male C57Bl6 mice, divided into 4 groups: SAL, ELASTASE CONTROL (EC), ELASTASE + PREVENTIVE ANTI-IL-17 (EP), and ELASTASE + THERAPEUTIC ANTI-IL-17 (ET). On the 29th day, animals were anesthetized with thiopental, tracheotomized, and placed on a ventilator to evaluate lung mechanical, exhaled nitric oxide (eNO), and total cells of bronchoalveolar lavage fluid was collected. We performed histological techniques, and linear mean intercept (Lm) was analyzed. Both treatments with anti-IL-17 decreased respiratory resistance and elastance, airway resistance, elastance of pulmonary parenchyma, eNO, and Lm compared with EC. There was reduction in total cells and macrophages in ET compared with EC. Both treatments decreased nuclear factor-кB, inducible nitric oxide synthase, matrix metalloproteinase (MMP)-9, MMP-12, transforming growth factor-β, tumor necrosis factor-α, neutrophils, IL-1β, isoprostane, and IL-17 in airways and alveolar septa; collagen fibers, decorin and lumican in airways; and elastic fibers and fibronectin in alveolar septa compared with EC. There was reduction of collagen fibers in alveolar septa and biglycan in airways in EP and a reduction of eNO synthase in airways in ET. In conclusion, both treatments with anti-IL-17 contributed to improve most of parameters evaluated in inflammation and extracellular matrix remodeling in this model of lung injury.

Network Pharmacology-Based Study on the Mechanism of Pinellia ternata in Asthma Treatment

Background

Pinellia ternata (PT), a medicinal plant, has had an extensive application in the treatment of asthma in China, whereas its underlying pharmacological mechanisms remain unclear.

Methods

Firstly, a network pharmacology method was adopted to collect activated components of PT from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Targets of PT were assessed by exploiting the PharmMapper website; asthma-related targets were collected from the OMIM website, and target-target interaction networks were built. Secondly, critical nodes exhibiting high possibility were identified as the hub nodes in the network, which were employed to conduct Gene Ontology (GO) comment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway enrichment analysis. Finally, the tissue expression profiles of key candidate genes were identified by the Gene Expression Omnibus (GEO) database, and the therapeutic effect of PT was verified by an animal experiment.

Results

57 achievable targets of PT on asthma were confirmed as hub nodes through using the network pharmacology method. As revealed from the KEGG enrichment analysis, the signaling pathways were notably enriched in pathways of the T-cell receptor signaling pathway, JAK-STAT signaling pathway, and cytokine-cytokine receptor interaction. The expression profiles of candidate genes including Mmp2, Nr3c1, il-10, il-4, il-13, il-17a, il-2, tlr4, tlr9, ccl2, csf2, and vefgα were identified. Moreover, according to transcriptome RNA sequencing data from lung tissues of allergic mice compared to normal mice, the mRNA level of Mmp2 and il-4 was upregulated (P < 0.001). In animal experiments, PT could alleviate the allergic response of mice by inhibiting the activation of T-helper type 2 (TH2) cells and the expression of Mmp2 and il-4.

Conclusions

Our study provides candidate genes that may be either used for future studies related to diagnosis/prognosis or as targets for asthma management. Besides, animal experiments showed that PT could treat asthma by regulating the expression of Mmp2 and il-4.

Effects of Glucocorticoid-Induced Transcript 1 Gene Deficiency on Glucocorticoid Activation in Asthmatic Mice

Background:

Glucocorticoid (GC) is the first-line therapy for asthma, but some asthmatics are insensitive to it. Glucocorticoid-induced transcript 1 gene (GLCCI1) is reported to be associated with GCs efficiency in asthmatics, while its exact mechanism remains unknown.

Methods:

A total of 30 asthmatic patients received fluticasone propionate for 12 weeks. Forced expiratory volume in 1 s (FEV₁) and GLCCI1 expression were detected. Asthma model was constructed in wild-type and GLCCI1 knockout (GLCCI1^-/-) mice. Glucocorticoid receptor (GR) and mitogen-activated protein kinase phosphatase 1 (MKP-1) expression were detected by polymerase chain reaction and Western blotting (WB). The phosphorylation of p38 mitogen-activated protein kinase (MAPK) was also detected by WB.

Results:

In asthmatic patients, the change of FEV₁ was well positively correlated with change of GLCCI1 expression (r = 0.430, P = 0.022). In animal experiment, GR and MKP-1 mRNA levels were significantly decreased in asthmatic mice than in control mice (wild-type: GR: 0.769 vs. 1.000, P = 0.022; MKP-1: 0.493 vs. 1.000, P < 0.001. GLCCI1^-/-: GR: 0.629 vs. 1.645, P < 0.001; MKP-1: 0.377 vs. 2.146, P < 0.001). Hydroprednisone treatment significantly increased GR and MKP-1 mRNA expression levels than in asthmatic groups; however, GLCCI1^-/- asthmatic mice had less improvement (wild-type: GR: 1.517 vs. 0.769, P = 0.023; MKP-1: 1.036 vs. 0.493, P = 0.003. GLCCI1^-/-: GR: 0.846 vs. 0.629, P = 0.116; MKP-1: 0.475 vs. 0.377, P = 0.388). GLCCI1^-/- asthmatic mice had more obvious phosphorylation of p38 MAPK than wild-type asthmatic mice (9.060 vs. 3.484, P < 0.001). It was still higher even though after hydroprednisone treatment (6.440 vs. 2.630, P < 0.001).

Conclusions:

GLCCI1 deficiency in asthmatic mice inhibits the activation of GR and MKP-1 and leads to more obvious phosphorylation of p38 MAPK, leading to a decremental sensitivity to GCs.

Trial Registration:

ChiCTR.org.cn, ChiCTR-RCC-13003634; http://www.chictr.org.cn/showproj.aspx?proj=5926.

BCL-2 protects human and mouse Th17 cells from glucocorticoid-induced apoptosis

BACKGROUND

Glucocorticoid resistance has been associated with Th17-driven inflammation, the mechanisms of which are not clear. We determined whether human and mouse Th17 cells are resistant to glucocorticoid-induced apoptosis.

METHODS

Freshly isolated human blood Th17 cells and in vitro differentiated Th17 cells from IL-17F red fluorescent protein reporter mice were treated with dexamethasone, a potent glucocorticoid. Apoptosis was measured using annexin V and DAPI staining. Screening of apoptosis genes was performed using the apoptosis PCR array. Levels of molecules involved in apoptosis were measured using quantitative RT-PCR, flow cytometry, and Western blotting. Knockdown of BCL-2 in murine Th17 cells was performed via retroviral transduction. Cytokines were measured using ELISA. A murine Th17-driven severe asthma model was examined for Th17 glucocorticoid sensitivity in vivo.

RESULTS

Human and mouse Th17 cells and mouse Th2 cells were resistant to glucocorticoid-induced apoptosis. Th17 cells had glucocorticoid receptors levels comparable to those in other T effectors cells. Th17 cells had high levels of BCL-2, knockdown of which sensitized Th17 cells to dexamethasone-induced apoptosis. Production of IL-22, but not IL-17A and IL-17F, was suppressed by glucocorticoids. STAT3 phosphorylation in Th17 cells was insensitive to glucocorticoid inhibition. Lung Th17 cells in the murine severe asthma model were enhanced, rather than suppressed, by glucocorticoids.

CONCLUSION

Th17 cells are resistant to glucocorticoid-induced apoptosis and cytokine suppression, at least in part due to high levels of BCL-2. These findings support a role of Th17 cells in glucocorticoid-resistant inflammatory conditions such as certain endotypes of asthma.

Interleukin-17A in lipid metabolism and atherosclerosis

Interleukin-17 (IL-17) A, the most important cytokine of the IL-17 family predominantly secreted by T helper 17 (Th17) cells, plays a critical role in the development of inflammatory diseases. Its receptor is an obligate heterodimer composed of IL-17 receptor (IL-17R) A and C, the main members of the IL-17R family. Binding of IL-17A to the IL-17RA/C complex can activate a variety of downstream signaling pathways such as nuclear factor kappa-B (NF-κB), activator protein 1 (AP1) and CCAAT/enhancer-binding protein (C/EBP) to induce the expression of proinflammatory cytokines and chemokines. IL-17A also promotes mRNA stability. Growing evidence shows that IL-17A is involved in lipid metabolism and the pathogenesis of atherosclerosis, a chronic inflammatory arterial disease driven by both innate and adaptive immune responses to modified lipoproteins. In the current review, we describe recent progress on regulation and signaling of IL-17A, and highlight its impacts on lipid metabolism and atherosclerosis.