Small Proline-Rich Protein 3 Regulates IL-33/ILC2 Axis to Promote Allergic Airway Inflammation

Assessment of pulmonary fibrosis using weighted gene co-expression network analysis

For many industrial chemicals toxicological data is sparse regarding several regulatory endpoints, so there is a high and often unmet demand for NAMs that allow for screening and prioritization of these chemicals. In this proof of concept case study we propose multi-gene biomarkers of compounds' ability to induce lung fibrosis and demonstrate their application in vitro. For deriving these biomarkers we used weighted gene co-expression network analysis to reanalyze a study where the time-dependent pulmonary gene-expression in mice treated with bleomycin had been documented. We identified eight modules of 58 to 273 genes each which were particularly activated during the different phases (inflammatory; acute and late fibrotic) of the developing fibrosis. The modules' relation to lung fibrosis was substantiated by comparison to known markers of lung fibrosis from DisGenet. Finally, we show the modules' application as biomarkers of chemical inducers of lung fibrosis based on an in vitro study of four diketones. Clear differences could be found between the lung fibrosis inducing diketones and other compounds with regard to their tendency to induce dose-dependent increases of module activation as determined using a previously proposed differential activation score and the fraction of differentially expressed genes in the modules. Accordingly, this study highlights the potential use of composite biomarkers mechanistic screening for compound-induced lung fibrosis.

The production, function, and clinical applications of IL-33 in type 2 inflammation-related respiratory diseases

Epithelial-derived IL-33 (Interleukin-33), as a member of alarm signals, is a chemical substance produced under harmful stimuli that can promote innate immunity and activate adaptive immune responses. Type 2 inflammation refers to inflammation primarily mediated by Type 2 helper T cells (Th2), Type 2 innate lymphoid cells (ILC2), and related cytokines. Type 2 inflammation manifests in various forms in the lungs, with diseases such as asthma and chronic obstructive pulmonary disease chronic obstructive pulmonary disease (COPD) closely associated with Type 2 inflammation. Recent research suggests that IL-33 has a promoting effect on Type 2 inflammation in the lungs and can be regarded as an alarm signal for Type 2 inflammation. This article provides an overview of the mechanisms and related targets of IL-33 in the development of lung diseases caused by Type 2 inflammation, and summarizes the associated treatment methods. Analyzing lung diseases from a new perspective through the alarm of Type 2 inflammation helps to gain a deeper understanding of the pathogenesis of these related lung diseases. This, in turn, facilitates a better understanding of the latest treatment methods and potential therapeutic targets for diseases, with the expectation that targeting lL-33 can propose new strategies for disease prevention.

Demethylzeylasteral (T-96) Alleviates Allergic Asthma via Inhibiting MAPK/ERK and NF-κB Pathway

INTRODUCTION

Demethylzeylasteral (T-96), a new extract of Tripterygium wilfordii Hook F, exerted immunomodulatory properties in autoimmune diseases, but its effect on airway inflammatory diseases remains unclear. Our study aims to explore the protective effect and underlying mechanism of T-96 in allergic asthma.

METHODS

The OVA-induced asthmatic mice were administered by gavage with T-96 (0.1 mg/10 g, 0.3 mg/10 g, or 0.6 mg/10 g) 1 h before each challenge. The airway hyperresponsiveness was assessed, pathological changes were evaluated by HE and PAS staining, and expressions of Th2 cytokines were determined by PCR and ELISA. The activation of MAPK/ERK and NF-κB pathway was assessed by western blot.

RESULTS

T-96 significantly relieved airway hyperresponsiveness in asthmatic mice, evidenced by reduced airway resistance (Raw) and increased lung compliance dynamic compliance (Cdyn). Also, enhanced inflammatory infiltration and mucus hypersecretion were ameliorated in lungs of asthmatic mice following increasing doses of T-96 treatment, accompanied by decreased eosinophils in bronchoalveolar lavage fluid (BALF), IgE and OVA-specific IgE levels in serum, and downregulated IL-5 and IL-13 expressions in BALF and lung tissues as well. Notably, phosphorylation levels of p38 MAPK, ERK, and p65 NF-κB were obviously increased in asthmatic mice compared with the control group, which were then abrogated upon T-96 treatment.

CONCLUSION

This study first revealed that T-96 alleviated allergic airway inflammation and airway hyperresponsiveness via inhibiting MAPK/ERK and NF-κB pathway. Thus, T-96 could potentially act as a new anti-inflammatory agent in allergic asthma.

Crocin Inhibits the Type 2 Inflammatory Response Produced by ILC2s in Eosinophilic Nasal Polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is subdivided into type 1 and type 2 inflammatory responses according to the mucosal inflammatory patterns. Crocin can reduce the level of T-helper type 2 cell (Th2) cytokines, such as interleukin-4 (IL-4), and inhibit the nuclear factor kappa-B (NF-κB) signaling pathway.

OBJECTIVE

This study aimed to investigate the role of group 2 innate lymphoid cells (ILC2s) in type 2 inflammation in eosinophilic nasal polyps and the inhibitory effect of crocin on this inflammation.

METHODS

Immunohistochemistry and immunofluorescence were used to detect the expression of transcription factors and the infiltration of ILC2s in tissues. An ILC2 stimulation model in vitro was constructed based on IL-33 stimulation and treated with crocin. The explant models were constructed and treated with crocin to detect the expression of type 2 inflammation-related factors.

RESULTS

Significantly more GATA-binding protein-3 (GATA3)-positive cells and chemoattractant receptor-homologous molecule expressed on T-helper type 2 cell (CRTH2)-positive cells, but fewer T-box expressed in T cell (T-bet)-positive cells, were found in eosinophilic nasal polyps (NPwEos). The expression levels of GATA3 and CRTH2 were significantly higher in NPwEos. Recombinant IL-33 stimulation increased the expression of GATA3, CRTH2, and type 2 cytokines (IL-4, IL-5, and IL-13) in ILC2s. In an IL-33-stimulated in vitro ILC2 culture model, crocin inhibited the type 2 inflammatory response, especially at lower concentrations (10 µM). The explant organoids of NPwEos were constructed in vitro, and Staphylococcus aureus enterotoxin B (SEB) was used to construct the type 2 inflammation model. Crocin at 10 µM concentration inhibited type 2 inflammation induced by SEB-stimulated explants.

CONCLUSION

Crocin inhibited type 2 inflammation induced by ILC2 activation at low concentrations via inhibiting the activation of NF-κB.

Type 2 innate lymphoid cell-derived amphiregulin regulates type II alveolar epithelial cell transdifferentiation in a mouse model of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a common complication in preterm infants characterized by alveolar growth arrest. Interleukin (IL)-33 and type 2 innate lymphoid cell (ILC2) affect type II alveolar epithelial cell (AECII) differentiation in BPD mice and may cause increased lung epithelial-mesenchymal transition (EMT). Amphiregulin (AREG) can be produced by ILC2 and is associated with tissue repair. However, the action mechanism of AREG produced by ILC2 to alveolar development in BPD is unclear. In this study, we aimed to demonstrate the role and mechanism of AREG in influencing AECII transdifferentiation in the lung tissue of BPD mice. The effects of ILC2-derived AREG on AECII transdifferentiation were verified in vivo and in vitro, and the role of IL-33 on ILC2-derived AREG in AECII transdifferentiation in BPD mice and a preliminary investigation of the role of AREG's receptor-epidermal growth factor receptor (EGFR) on AECII transdifferentiation. The results showed that neonatal mice developed severe lung injury after hyperoxia, and IL-33 induced AREG production via ILC2 affected normal AECII differentiation and promoted EMT. In addition, the blockade of EGFR was found to alleviate the impaired AECII differentiation under hyperoxia in an in vitro study. In summary, our study demonstrates that AREG secreted by ILC2 affects AECII transdifferentiation in BPD mice, which provides a new idea for the clinical treatment of BPD.

A Deep View of the Biological Property of Interleukin-33 and Its Dysfunction in the Gut

Intestinal diseases have always posed a serious threat to human health, with inflammatory bowel disease (IBD) being one of them. IBD is an autoimmune disease characterized by chronic inflammation, including ulcerative colitis (UC) and Crohn's disease (CD). The "alarm" cytokine IL-33, which is intimately associated with Th2 immunity, is a highly potent inflammatory factor that is considered to have dual functions-operating as both a pro-inflammatory cytokine and a transcriptional regulator. IL-33 has been shown to play a crucial role in both the onset and development of IBD. Therefore, this review focuses on the pathogenesis of IBD, the major receptor cell types, and the activities of IL-33 in innate and adaptive immunity, as well as its underlying mechanisms and conflicting conclusions in IBD. We have also summarized different medicines targeted to IL-33-associated diseases. Furthermore, we have emphasized the role of IL-33 in gastrointestinal cancer and parasitic infections, giving novel prospective therapeutic utility in the future application of IL-33.

Regulatory roles of Osteopontin in lung epithelial inflammation and epithelial-telocyte interaction

BACKGROUND

Lung epithelial cells play important roles in lung inflammation and injury, although mechanisms remain unclear. Osteopontin (OPN) has essential roles in epithelial damage and repair and in lung cancer biological behaviours. Telocyte (TC) is a type of interstitial cell that interacts with epithelial cells to alleviate acute inflammation and lung injury. The present studies aim at exploring potential mechanisms by which OPN regulates the epithelial origin lung inflammation and the interaction of epithelial cells with TCs in acute and chronic lung injury.

METHODS

The lung disease specificity of OPN and epithelial inflammation were defined by bioinformatics. We evaluated the regulatory roles of OPN in OPN-knockdown or over-expressed bronchial epithelia (HBEs) challenged with cigarette smoke extracts (CSE) or in animals with genome OPN knockout (gKO) or lung conditional OPN knockout (cKO). Acute lung injury and chronic obstructive pulmonary disease (COPD) were induced by smoking or lipopolysaccharide (LPS). Effects of OPN on PI3K subunits and ERK were assessed using the inhibitors. Spatialization and distribution of OPN, OPN-positive epithelial subtypes, and TCs were defined by spatial transcriptomics. The interaction between HBEs and TCs was assayed by the co-culture system.

RESULTS

Levels of OPN expression increased in smokers, smokers with COPD, and smokers with COPD and lung cancer, as compared with healthy nonsmokers. LPS and/or CSE induced over-production of cytokines from HBEs, dependent upon the dysfunction of OPN. The severity of lung inflammation and injury was significantly lower in OPN-gKO or OPN-cKO mice. HBEs transferred with OPN enhanced the expression of phosphoinositide 3-kinase (PI3K)CA/p110α, PIK3CB/p110β, PIK3CD/p110δ, PIK3CG/p110γ, PIK3R1, PIK3R2 or PIK3R3. Spatial locations of OPN and OPN-positive epithelial subtypes showed the tight contact of airway epithelia and TCs. Epithelial OPN regulated the epithelial communication with TCs, and the down-regulation of OPN induced more alterations in transcriptomic profiles than the up-regulation.

CONCLUSION

Our data evidenced that OPN regulated lung epithelial inflammation, injury, and cell communication between epithelium and TCs in acute and chronic lung injury. The conditional control of lung epithelial OPN may be an alternative for preventing and treating epithelial-origin lung inflammation and injury.

Interleukin-33 increases type 2 innate lymphoid cell count and their activation in eosinophilic asthma

BACKGROUND

Interleukin-33 (IL-33) exacerbates asthma probably through type 2 innate lymphoid cells (ILC2s). Nevertheless, the association between eosinophilic asthma (EA) and ILC2s remains obscure, and the mechanisms by which IL-33 affects ILC2s are yet to be clarified.

METHODS

ILC2s were evaluated in peripheral blood mononuclear cells, induced sputum, and bronchoalveolar lavage fluid obtained from patients with EA. Confocal microscopy was performed to locate ILC2s in lung tissue and the mRNA expression of ILC2-related genes was also evaluated in the EA model. The proliferation of ILC2s isolated from humans and mice was assessed following IL-33 or anti-IL-33 stimulation.

RESULTS

The counts, activation, and mRNA expression of relevant genes in ILC2s were higher in PBMCs and airways of patients with EA. In addition, ILC2 cell counts correlated with Asthma control test, blood eosinophil count, Fractional exhaled nitric oxide level, and predicted eosinophilic airway inflammation. IL-33 induced stronger proliferation of ILC2s and increased their density around blood vessels in the lungs of mice with EA. Moreover, IL-33 treatment increased the counts and activation of ILC2s and lung inflammatory scores, whereas anti-IL-33 antibody significantly reversed these effects in EA mice. Finally, IL-33 enhanced PI3K and AKT protein expression in ILC2s, whereas inhibition of the PI3K/AKT pathway decreased IL-5 and IL-13 production by ILC2s in EA.

CONCLUSIONS

ILC2s, especially activated ILC2s, might be critical markers of EA. IL-33 can induce and activate ILC2s in the lungs via the PI3K/AKT pathway in EA. Thus, using anti-IL-33 antibody could be a part of an effective treatment strategy for EA.

Evolutionary Conserved Short Linear Motifs Provide Insights into the Cellular Response to Stress

Short linear motifs (SLiMs) are evolutionarily conserved functional modules of proteins composed of 3 to 10 residues and involved in multiple cellular functions. Here, we performed a search for SLiMs that exert sequence similarity to two segments of alpha-fetoprotein (AFP), a major mammalian embryonic and cancer-associated protein. Biological activities of the peptides, LDSYQCT (AFP_14-20) and EMTPVNPGV (GIP-9), have been previously confirmed under in vitro and in vivo conditions. In our study, we retrieved a vast array of proteins that contain SLiMs of interest from both prokaryotic and eukaryotic species, including viruses, bacteria, archaea, invertebrates, and vertebrates. Comprehensive Gene Ontology enrichment analysis showed that proteins from multiple functional classes, including enzymes, transcription factors, as well as those involved in signaling, cell cycle, and quality control, and ribosomal proteins were implicated in cellular adaptation to environmental stress conditions. These include response to oxidative and metabolic stress, hypoxia, DNA and RNA damage, protein degradation, as well as antimicrobial, antiviral, and immune response. Thus, our data enabled insights into the common functions of SLiMs evolutionary conserved across all taxonomic categories. These SLiMs can serve as important players in cellular adaptation to stress, which is crucial for cell functioning.

Qizhi Kebitong Formula Ameliorates Streptozocin-Induced Diabetic Osteoporosis through Regulating the PI3K/Akt/NF-κB Pathway

Background

Diabetic osteoporosis (DOP) is a progressive osteoblast dysfunction induced by high glucose, which has negative impacts on bone homeostasis. Qizhi Kebitong formula (QKF) is a traditional Chinese medicine (TCM) formula for treating DOP. However, its role in the protection of DOP has not been clarified yet. Here, we aimed to explore the potential mechanisms of QKF on DOP development via in vivo experiment.

Methods

Network pharmacology was used to detect the key targets and signaling pathways of QKF on DOP. The effects of QKF on DOP were examined by the phenotypic characteristics, micro-CT, and hematoxylin-eosin (H&E) staining. The predicted targets and pathways were validated by a streptozocin- (STZ-) induced mouse model. Subsequently, the levels of the selected genes and proteins were analyzed using qRT-PCR and Western blot. Finally, AutoDock and PyMOL were used for molecular docking.

Results

In this study, 90 active compounds and 2970 related disease targets have been found through network pharmacology. And QKF could improve the microstructures of femur bone mass, reduce inflammatory cell infiltration, and downregulate the levels of TNF-α, IKBKB, IL-6, and IL-1β. Moreover, the underlying effect of PI3K/Akt/NF-κB pathways was also recommended in the treatment.

Conclusion

Altogether, our findings suggested that QKF could markedly alleviate osteoblast dysfunction by modulating the key targets and PI3K/Akt/NF-κB signaling pathway.

ILC2s expanded by exogenous IL-33 regulate CD45+CD11b+F4/80high macrophage polarization to alleviate hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury (IRI) is an adverse consequence of hepatectomy or liver transplantation. Recently, immune mechanisms involved in hepatic IRI have attracted increased attention of investigators working in this area. In specific, group 2 innate lymphoid cells (ILC2s), have been strongly implicated in mediating type 2 inflammation. However, their immune mechanisms as involved with hepatic IRI remain unclear. Here, we reported that the population of ILC2s is increased with the development of hepatic IRI as shown in a mouse model in initial stage. Moreover, M2 type CD45+CD11b+F4/80high macrophages increased and reached maximal levels at 24 h followed by a significant elevation in IL-4 levels. We injected exogenous IL-33 into the tail vein of mice as a mean to stimulate ILC2s production. This stimulation of ILC2s resulted in a protective effect upon hepatic IRI along with an increase in M2 type CD45+CD11b+F4/80high macrophages. In contrast, depletion of ILC2s as achieved with use of an anti-CD90.2 antibody substantially abolished this protective effect of exogenous IL-33 and M2 type CD45+CD11b+F4/80high macrophage polarization in hepatic IRI. Therefore, this exogenous IL-33 induced potentiation of ILC2s appears to regulate the polarization of CD45+CD11b+F4/80high macrophages to alleviate IRI. Such findings provide the foundation for the development of new targets and strategies in the treatment of hepatic IRI.