Regulatory effect of glutathione on treg/Th17 cell balance in allergic rhinitis patients through inhibiting intracellular autophagy

Microenvironment modulation by key regulators of RNA N6-methyladenosine modification in respiratory allergic diseases

BACKGROUND

RNA N6-methyladenosine (m6A) regulators are considered post-transcriptional regulators that affect several biological functions, and their role in immunity, in particular, is emerging. However, the role of m6A regulators in respiratory allergic diseases remains unclear. Therefore, we aimed to investigate the role of key m6A regulators in mediating respiratory allergic diseases and immune microenvironment infiltration characteristics.

METHODS

We downloaded gene expression profiles of respiratory allergies from the Gene Expression Omnibus (GEO) database and we performed hierarchical clustering, difference analysis, and construction of predictive models to identify hub m6A regulators that affect respiratory allergies. Next, we investigate the underlying biological mechanisms of key m6A regulators by performing PPI network analysis, functional enrichment analysis, and immune microenvironment infiltration analysis. In addition, we performed a drug sensitivity analysis on the key m6A regulator, hoping to be able to provide some implications for clinical medication.

RESULTS

In this study, we identified four hub m6A regulators that affect the respiratory allergy and investigated the underlying biological mechanisms. In addition, studies on the characteristics of immune microenvironment infiltration revealed that the expression of METTL14, METTL16, and RBM15B correlated with the infiltration of the mast and Th2 cells in respiratory allergy, and METTL16 expression was found to be significantly negatively correlated with macrophages for the first time (R = -0.53, P < 0.01). Finally, a key m6A regulator, METTL14, was screened by combining multiple algorithms. In addition, by performing a drug sensitivity analysis on METTL14, we hypothesized that it may play an important role in the improvement of allergic symptoms in the upper and lower airways with topical nasal glucocorticoids.

CONCLUSIONS

Our findings suggest that m6A regulators, particularly METTL14, play a crucial role in the development of respiratory allergic diseases and the infiltration of immune cells. These results may provide insight into the mechanism of action of methylprednisolone in treating respiratory allergic diseases.

Relationship Between the Expression of LC3 (Microtubule-Associated Protein 1A/1B-Light Chain 3) in Nasal Mucosa and Serum IL-5 and IL-4 Concentrations in Allergic Rhinitis Mice

Objective

To investigate the expression and correlation of autophagy-related microtubule-associated protein 1 light chain 3 beta LC3 and interleukin-5 IL-5 in allergic rhinitis AR.

Methods

Fifty-six 7-week-old BALC/C mice were randomly divided into experimental group (n = 56) and control group (n = 8). The experimental group used Dermatophagoides farinae (Der f) for AR modeling, and control group used PBS solution. As the experimental group sampled at 6 time points, and 8 mice were sacrificed each time, while the control group was sacrificed 24 hours after the last dose. The contents of serum IL-4, IL-5, and dust mite specific IgE HDM-sIgE in mice were detected by enzyme-linked immunosorbent assay ELISA, and the morphological changes of nasal mucosa were detected by a hematoxylin-eosin H&E staining. The expression of LC3 in mouse nasal mucosa was detected by immunohistochemical staining. Spearman correlation coefficient was used to assess the relationship between LC3 and IL-5 levels.

Results

In AR mice modelled with dust mites, the serum levels of IL-4 and HDM-sIgE increased gradually, and the serum IL-5 concentration had a peak at the early intraperitoneal administration stage similar to that at the end of modelling. The LC3 level in nasal mucosa of AR mice modelled with dust mites increased gradually in the early stages, but stabilized in the later stages. The expression of LC3 level in nasal mucosa was a positively correlated ration between serum IL-5 level in AR mice.

Conclusion

In the early stage of AR mice, the level of nasal mucosal autophagy and serum IL-5 levels were significantly increased and correlated, suggesting that nasal mucosal autophagy played a promoting role in the early stage of AR.

Luteolin restored Treg/Th17 balance to ameliorate allergic rhinitis in a mouse model

OBJECTIVE

Luteolin (LO) has been reported to be a potential drug for allergic rhinitis (AR). This paper explored the mechanism of LO in AR.

MATERIALS AND METHODS

Mice were treated with ovalbumin (OVA) to construct an AR model in vivo before LO or 3-methyladenine (3-MA) treatment. The frequency of nasal sneezing was counted. The nasal mucosa thickness was assessed by hematoxylin-eosin staining assay. The levels of anti-OVA-immunoglobulin E (IgE)/IgG2a, autophagy-related factors (Beclin1, LC3II/LC3I), and T helper cell 17 (Th17)/regulatory T cell (Treg) markers (interleukin (IL)-17A, retinoic acid receptor-related orphan nuclear receptor γt (RORγt)/IL-10, forkhead box P3 (Foxp3)) were detected through enzyme-linked immunosorbent assay, western blot, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Flow cytometry assay was performed to test the percentage of Th17 and Treg cells.

RESULTS

The nasal sneezing frequency, nasal mucosa thickness, and levels of anti-OVA-IgE, Beclin1, LC3II/LC3I, IL-17A as well as RORγt were enhanced whereas anti-OVA-IgG2a, IL-10, and Foxp3 levels were inhibited in a mouse model of OVA-induced AR, which were reversed by LO or 3-MA treatment.

CONCLUSIONS

LO restored Treg/Th17 balance to ameliorate AR in a mouse model.

Integration of transcriptomics and metabolomics to reveal the effect of ginsenoside Rg3 on allergic rhinitis in mice

Increasing studies have demonstrated that ginsenoside Rg3 (Rg3) plays an important role in the prevention and treatment of various diseases, including allergic lower airway inflammation such as asthma. To investigate the role of Rg3 in allergic upper airway disease, the effect and therapeutic mechanism of Rg3 in allergic rhinitis (AR) were studied. Ovalbumin-induced AR model mice were intragastrically administered with Rg3. Nasal symptoms, levels of IgE, IL-4, IL-5, IL-13, SOD and MDA in serum, and histopathological analysis of nasal mucosa were used to evaluate the effect of Rg3 on ameliorating AR in mice. Moreover, nasal mucosa samples from the normal control group, AR model group and high dosage of Rg3 were collected to perform omics analysis. The differentially expressed genes and significantly changed metabolites were screened based on transcriptomics and metabolomics analyses, respectively. Integrative analysis was further performed to confirm the hub genes, metabolites and pathways. After Rg3 intervention, the nasal symptoms and inflammatory infiltration were effectively improved, the levels of IgE, IL-4, IL-5, IL-13 and MDA were significantly reduced, and the level of SOD was obviously increased. The results of the qRT-PCR assay complemented the transcriptomic findings. Integrated analysis showed that Rg3 played an anti-AR role mainly by regulating the interaction network, which was constructed by 12 genes, 8 metabolites and 4 pathways. Our findings suggested that Rg3 had a therapeutic effect on ovalbumin-induced AR in mice by inhibiting inflammation development and reducing oxidative stress. The present study could provide a potential natural agent for the treatment of AR.

Angiotensin converting enzyme 2 activation improves allergic rhinitis and suppresses Th2 cytokine release

OBJECTIVE

Allergic rhinitis (AR) is primarily regulated by type I hypersensitivity, with Th2 and immunoglobulin E (IgE) playing essential roles. This study aimed to determine whether angiotensin converting enzyme (ACE)2 could participate in the regulation of AR.

METHODS

Nasal mucosal tissues of AR patients were collected to determine ACE2 levels. Following AR mouse models were established, ACE2 levels in nasal mucosa were determined. Then the influences of diminazene aceturate (ACE2 agonist) on AR symptoms, pathology, specific antibodies, histamine, and interleukins (ILs) release in vivo were evaluated. Afterward, human nasal mucosa epithelial cells were exposed to IL-13, and the impacts of ACE2 overexpression on the secretion of pro-inflammatory factors in vitro were assessed.

RESULTS

ACE2 levels significantly declined in nasal mucosa both in patients and mouse models (p < .001). Diminazene aceturate treatment elevated the ACE2 level in mice (p < .01), accompanied by reduced frequency of nasal spray and nasal friction, decreased eosinophils and goblet cells (p < .001) according to histopathological staining. Furthermore, lgE, lgG1, histamine, and IL levels in mice were also decreased (p < .05). In vitro experiments revealed that ACE2 overexpression suppressed the secretion of pro-inflammatory factors (p < .001).

CONCLUSION

Together, ACE2 activation can alleviate the symptoms of AR in mice and inhibit the release of Th2 cytokines. Activating ACE2 is a promising therapeutic approach for AR.

Programmed cell death in the epithelial cells of the nasal mucosa in allergic rhinitis

In AR, the epithelial barrier composed of Nasal epithelial cells is the first line of defense, which is crucial to protect the host immune system from harmful stimuli. Moreover, irreversible structural changes in Nasal epithelial cells can occur in response to different allergens, but the mechanism leading to such abnormal changes has not been determined. Programmed cell death is regulated by genes and interacts with multiple cell signaling pathways. To explore the regulatory mechanism and signal pathway of programmed cell death in epithelial cells of allergic rhinitis, is helpful to clarify the pathogenesis of AR and put forward treatment strategies. In this paper, the regulation mechanisms of programmed cell death such as apoptosis, pyroptosis, and autophagy occurring in epithelial cells in AR, are retrospectively summarized to better understand the pathogenesis of AR.

LncRNA ANRIL Promotes Autophagy Activation Through miR-16-5p/TLR4 Axis in Allergic Rhinitis

BACKGROUND

Allergic rhinitis (AR) is an allergic disease of nasal mucosa. LncRNAs are key modulators affecting AR development. Neverthelss, the impact of lncRNA ANRIL in AR is not clear.

OBJECTIVE

This work decided to study the mechanism underlying the impact of ANRIL on TLR4 expression through targeting miR-16-5p during autophagy and epithelial barrier dysfunction in the progression of AR.

METHODS

Human nasal epithelial cells were exposed to TNF-α to establish AR cell model, AR mice model was constructed by ovalbumin (OVA) treatment. QRT-PCR or western blot assays were applied to measure the levels of mRNA and proteins. Dual-luciferase reporter gene detection and RIP assay were conducted to verify the association between ANRIL and miR-16-5p. Autophagy flux assessment by mRFP-GFP-LC3 method was performed to detect autophagy level.

RESULTS

AR progression could induce the autophagy, and the expressions of tight junction proteins were downregulated in AR cell model. Moreover, knockdown of ANRIL reversed the effect of AR on autophagy-related protein and tight junction proteins MiR-16-5p was found to be bound with ANRIL and miR-16-5p inhibitor could reverse ANRIL knockdown-induced downregulation of autophagy-related proteins and epithelial barrier dysfunction. In addition, miR-16-5p directly targeted TLR4. Furthermore, knockdown of ANRIL reversed miR-16-5p and TLR4 expression, autophagy level, and tight junction protein levels in nasal mucosa of AR mice.

CONCLUSION

This study illustrated that ANRIL acted as a promotion factor in AR induced autophagy and epithelial barrier dysfunction by enhancing the expression of TLR4 via interacting with miR-16-5p.

USP7-SOX9-miR-96-5p-NLRP3 network regulates myocardial injury and cardiomyocyte pyroptosis in sepsis

Sepsis is a common life-threatening pathology. This study investigated the role of transcription factor sex-determining region Y (SRY)-box 9 (SOX9) in sepsis-induced cardiomyocyte pyroptosis. A murine model of sepsis was established, followed by detection of cardiac functions and myocardial injury. HL-1 cells were induced by lipopolysaccharides (LPS). The levels of IL-18, IL-1β, TNF-α, IL-6, MDA, and SOD in myocardial tissues and HL-1 cells were determined. SOX9 ubiquitination level was measured. The binding relationships between SOX9-miR-96-5p and miR-96-5p-NLRP3 were analyzed, and the interaction between ubiquitin-specific peptidase 7 (USP7) and SOX9 was measured. SOX9 was highly expressed in septic mice and LPS-induced HL-1 cells. SOX9 silencing improved cardiac function, alleviated myocardial injury, reduced the levels of IL-1β, IL-18, cleaved caspase-1, GSDMD-N, TNF-α, IL-6, and MDA in myocardial tissues and HL-1 cells, increased the level of SOD, and alleviated cardiomyocyte pyroptosis. USP7 upregulated SOX9 expression through deubiquitination. SOX9 inhibited miR-96-5p expression and miR-96-5p targeted NLRP3. miR-96-5p silencing or USP7 overexpression reversed the inhibitory effect of SOX9 silencing on cardiomyocyte pyroptosis. Collectively, USP7 upregulated SOX9 expression through deubiquitination, and SOX9 suppressed miR-96-5p expression by binding to the miR-96-5p promoter region, thereby promoting NLRP3 expression and then exacerbating sepsis-induced myocardial injury and cardiomyocyte pyroptosis.

Astragalus Polysaccharide Relieves Inflammatory Responses in Guinea Pigs with Allergic Rhinitis via Ameliorating NF-kB-Mediated Treg/Th17 Imbalance

BACKGROUND

Allergic rhinitis (AR) is regarded as a prevalent and non-infectious inflammation in nasal mucosa, and astragalus polysaccharide (APS) could mitigate inflammation.

OBJECTIVES

Herein, this study probed the specific mechanism of APS in inflammatory responses in AR.

METHODS

Firstly, AR guinea pig models were established through the stimulation and sensitization of ovalbumin (OVA) and received APS treatment. Changes in nasal symptoms were assessed through counting the sneezing and rubbing times of guinea pigs. The change patterns of OVA-specific immunoglobulin-E (OVA-sIgE), OVA-specific immunoglobulin-G1 (OVA-sIgG1), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 in guinea pig serum were identified. Meanwhile, the levels of IL-17, transforming growth factor (TGF)-β, IL-10, and forkhead box protein P3 (Foxp3) in the guinea pig tissues or serum were examined, and CD25⁺Foxp3⁺Treg or CD4⁺IL17⁺Th17 cell proportion was detected. Afterwards, nuclear factor-kappa B (NF-kB) expression in guinea pig nasal mucosa tissues were examined. Rescue experiments were designed to probe the role of NF-kB overexpression in inflammatory responses and Treg/Th17 imbalance in AR guinea pigs.

RESULTS

APS treatment reduced sneezing and rubbing times of AR guinea pigs and suppressed OVA-sIgE, OVA-sIgG1, TNF-α, and IL-6 levels in guinea pig serum, and meanwhile, increased CD25⁺Foxp3⁺Treg cell proportion while reduced CD4⁺IL17⁺Th17 cell proportion in AR guinea pig serum or tissues, in a dose-dependent manner. NF-kB was highly-expressed in AR guinea pigs and down-regulated after APS treatment. NF-kB overexpression facilitated inflammatory responses and Treg/Th17 imbalance in AR.

CONCLUSION

APS reduced Treg/Th17 imbalance via suppressing NF-kB expression, thereby ameliorating inflammatory responses in AR.