Endoplasmic reticulum stress promotes local immunoglobulin E production in allergic rhinitis

LncRNA FOXD3-AS1 modulates ER stress and epithelial barrier dysfunction in allergic rhinitis by destabilizing CHOP mRNA

BACKGROUND

Allergic rhinitis (AR) is an allergic disease of nasal mucosa. LncRNAs are key modulators affecting AR development. Nevertheless, the impact of LncRNA FOXD3-AS1 in AR is not clear.

METHODS

Human nasal epithelial cells (hNECs) were exposed to ovalbumin (OVA) to establish AR cell model, AR mice model was also constructed by OVA treatment. RIP assay was conducted to verify the association between FOXD3-AS1 and RBM15B. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analyses were performed to detect the expression of ER stress markers: Autophagy Related Gene 4 (ATG4), phosphorylated Protein kinase R-like endoplasmic reticulum kinase (p-PERK), and phosphorylated eukaryotic initiation factor 2α (p-eIF2α) in hNECs after overexpression of FOXD3-AS1. HNECs were treated with ER stress inhibitor 4-phenylbutyric acid (4-PBA).

RESULTS

The expressions of LncRNA FOXD3-AS1 were downregulated in AR model. Moreover, overexpression FOXD3-AS1 reversed the effect of AR on ER stress markers. RBM15B was found to be bound with FOXD3-AS1. After 4-PBA treatment, the protein expression of ATG4, CHOP, p-PERK, and p-eIF2α was significantly reduced in cultured AR cell model.

CONCLUSION

This study illustrated that FOXD3-AS1 acted as an inhibitor in AR induced ER stress and epithelial barrier dysfunction by destabilizing CHOP mRNA via RBM15B.

LPCAT1 reduces inflammatory response, apoptosis and barrier damage of nasal mucosal epithelial cells caused by allergic rhinitis through endoplasmic reticulum stress

Allergic rhinitis (AR), common in children and adolescents, involves Lysophosphatidylcholine acyltransferase 1 (LPCAT1) catalyzing surfactant lipid biosynthesis and suppressing endoplasmic reticulum expression. However, the precise mechanism underlying the impact of LPCAT1 on epithelial cell damage in AR remains elusive. Hence, the present investigation elucidated the potential effect of LPCAT1 on epithelial cell damage in AR by inhibiting endoplasmic reticulum stress. To assess cell viability, CCK8 assay was employed. Additionally, western blotting was utilized to evaluate the expression of endoplasmic reticulum stress-associated proteins ATF6, CHOP, p-eIF2α, p-IRE1, and LPCAT1. Subsequently, an interference plasmid targeting LPCAT1 was constructed, and western blot analysis was conducted to determine interference level of LPCAT1. An ELISA assay was employed to quantify the concentrations of TNFα, IL-1β, IL-6, GM-CSF, and eotaxin. Additionally, flow cytometry and western blotting techniques were utilized to evaluate cellular apoptosis, whereas immunofluorescence staining was applied to detect the expression levels of ZO-1. Our findings indicated that IL-13 stimulation resulted in an elevated expression of ER stress proteins and LPCAT1 in nasal mucosal epithelial cells. Furthermore, LPCAT1 interference diminished the expression of inflammatory mediators, apoptosis markers, barrier disruption indicators, and ER stress proteins in IL-13-stimulated nasal mucosal epithelial cells. Further, by inhibiting ER stress, LPCAT1 interference diminished the expression of inflammatory factors, apoptosis, and barrier damage in nasal mucosal epithelial cells stimulated by IL-13. Concisely, LPCAT1 ameliorates AR-induced inflammation, apoptosis, and barrier impairment in nasal mucosal epithelial cells by modulating ER stress, implying its potential as a novel therapeutic target for AR.

Jingfang Granules alleviates OVA-induced allergic rhinitis through regulating endoplasmic reticulum stress signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Jingfang Granules (JF) is a modified herbal compound preparation that is empirically used in clinical practice for the treatment of allergic diseases. Nevertheless, the role of JF in allergic rhinitis (AR) has yet to be demonstrated, and its potential mechanisms of action remain to be fully evaluated.

AIM OF STUDY

The objective of this research is to examine the underlying mechanisms by which JF can be used to treat AR. This will be achieved through the use of an ovalbumin (OVA)/aluminum hydroxide AR model in mice.

MATERIALS AND METHODS

ICR mice were administered an intraperitoneal (i.p.) injection of OVA/aluminium hydroxide in order to permit the establishment of an AR model. Following the intragastric administration of JF to the mice, testing nose scratching and sneezing behavior in mice to determine modeling status, and stained transverse sections of the mouse nose using the Hematoxylin and Eosin (H&E) method were in vitro evaluated to assess the histological effects of JF on mice with AR. The regulatory network was subjected to proteomic and metabolomic investigation. The expression of serum cytokines as well as histamine (HIS) was detected using ELISA kits. Protein expression in nasal mucosal tissues was identified through the use of a Western blot.

RESULTS

JF demonstrated a notable reduction in nose-scratching and sneezing in AR mice. Concurrently, JF markedly reduced IgE, IL-4, IL-6, IL-13, TNF-α and HIS levels while elevating IFN-γ levels in the serum of AR mice. This was achieved by inhibiting the endoplasmic reticulum (ER) stress-related protein associated proteins including GADD and ATF4, p-eIF2α, p-IRE1α, XBP1s and p-PERK. Proteomics, metabolomics, Western blotting and Quantitative Real-time polymerase chain reaction (qPCR) results confirmed that JF inhibits the glycolysis/arginine biosynthesis pathway by suppressing the ER stress (ERs) signaling pathway, which in turn inhibits the inflammatory response.

CONCLUSION

Findings from the present study indicate that JF is an efficacious treatment for OVA/aluminum hydroxide-induced nasal mucosal injury and inflammation in mice. Furthermore, the study demonstrated that JF exhibited anti-AR clinic pharmacological effects by modulating the ERs signaling pathway and inhibiting glycolysis as well as arginine biosynthesis.

Endoplasmic Reticulum Stress Promotes Telomerase Reverse Transcriptase Expression Contributes to Development of Allergic Rhinitis

BACKGROUND

The Th2 cell polarization is a crucial factor in the pathogenesis of allergic diseases. The underlying mechanism requires further investigation. Telomerase has an immune-regulating ability. The aim of this study is to elucidate the association between telomerase and Th2 cell polarization in patients with allergic rhinitis (AR).

METHODS

CD4+ T cells were isolated from blood samples collected from AR patients and healthy control subjects. RNA sequencing was employed to analyze RNA samples extracted from CD4+ T cells. An AR mouse model was established using the ovalbumin-alum protocol.

RESULTS

High telomerase gene activity and high endoplasmic reticulum (ER) stress status were observed in CD4+ T-cells in patients with AR. Positive correlation between the telomerase reverse transcriptase (TERT) gene expression in CD4+ T cells and AR response in patients with AR. TERT facilitated the degradation of Foxp3 proteins in CD4+ T cells, resulting in the polarization of Th2 cells. Sensitization with the ovalbumin-alum protocol enhanced the Tert expression in CD4+ T cells by exacerbating ER stress. Conditional inhibition of the Tert or eukaryotic translation initiation factor 2-α (Eif2a) expression in CD4+ T cells effectively attenuated experimental AR in mice.

CONCLUSIONS

Elevated amounts of telomerase in CD4+ T cells were found in CD4+ T cells of subjects with AR. Telomerase promoted Th2 cell polarization by inducing Foxp3 protein degradation and promotes GATA3 activation. Inhibition of TERT or eIF2a alleviated experimental AR.

Yingxiang Acupoint Embedding Improves Mucosal Barrier Function in Rats with Local Allergic Rhinitis

INTRODUCTION

Epithelial barrier disruption is the initial cause of various diseases. We previously reported that acupoint catgut embedding (AE) improves tight junction proteins (TJs) in rats with allergic rhinitis. However, whether AE improves the epithelial barrier in local allergic rhinitis (LAR) remains unknown.

METHODS

A total of 36 Sprague Dawley (SD) male rats aged 5-7 weeks were divided into 6 groups with 6 rats each: control group, LAR model group, false acupoint embedding + LAR group, acupoint embedding + LAR group, capsaicin + LAR group, and tunicamycin + acupoint embedding + LAR group. Behavioral observation, ELISA to detect inflammatory factors in nasal lavage fluid and serum IgE, nasal mucosal permeability test, hematoxylin-eosin staining, PCR to detect Substance P (SP), Western blot, and immunofluorescence to detect endoplasmic reticulum stress (ERS) index and TJs were used to investigate the mechanism of AE in LAR.

RESULTS

AE improved the symptoms and pathological features of nasal mucosa of LAR rats, reduced the inflammatory factors (IL4, IL5, IL13) of nasal lavage fluid, and showed no significant change in serum IgE levels in all groups. In addition, AE decreased the expression of SP in nasal mucosa of LAR rats, inhibited ERS, increased the expression of tight junction protein, reduced the permeability of nasal mucosa, and improved the function of nasal mucosal barrier.

CONCLUSION

This study confirms that AE can improve the nasal mucosal barrier function of LAR by reducing the expression of SP, inhibiting ERS and increasing the expression of TJs, thus enhancing the nasal mucosal barrier function.

Chemical chaperone TUDCA selectively inhibits production of allergen-specific IgE in a low-dose model of allergy

The cellular response to endoplasmic reticulum (ER) stress accompanies plasma cell maturation and is one of triggers and cofactors of the local inflammatory response. Chemical chaperones, low-molecular substances that eliminate pathological ER stress, are proposed as means of treating pathologies associated with ER stress. The aim of this study was to evaluate the effect and mechanisms of influence of chemical chaperones on the humoral response in a low-dose model of allergy. The allergic immune response was induced in BALB/c mice by repeated administration of ovalbumin at a dose of 100 ng for 6 weeks. Some animals were injected with both the antigen and the chemical chaperones, TUDCA (tauroursodeoxycholic acid) or 4-PBA (4-phenylbutyrate). Administration of TUDCA, but not 4-PBA, suppressed production of allergen-specific IgE (a 2.5-fold decrease in titer). None of the chemical chaperones affected the production of specific IgG1. The effect of TUDCA was associated with suppression of the switch to IgE synthesis in regional lymph nodes. This phenomenon was associated with suppressed expression of genes encoding cytokines involved in type 2 immune response, especially Il4 and Il9, which in turn could be caused by suppression of IL-33 release. In addition, TUDCA significantly suppressed expression of the cytokine APRIL, and to a lesser extent, BAFF. Thus, TUDCA inhibition of the allergy-specific IgE production is due to suppression of the release of IL-33 and a decrease in the production of type 2 immune response cytokines, as well as suppression of the expression of the cytokines APRIL and BAFF.

Acute activation of SERCA with CDN1163 attenuates IgE-mediated mast cell activation through selective impairment of ROS and p38 signaling

Mast cells are granulocytic immune sentinels present in vascularized tissues that drive chronic inflammatory mechanisms characteristic of allergic pathologies. IgE-mediated mast cell activation leads to a rapid mobilization of Ca²⁺ from intracellular stores, which is essential for the release of preformed mediators via degranulation and de novo synthesized proinflammatory cytokines and chemokines. Given its potent signaling capacity, the dynamics of Ca²⁺ localization are highly regulated by various pumps and channels controlling cytosolic Ca²⁺ concentrations. Among these is sarco/endoplasmic reticulum Ca²⁺ -ATPase (SERCA), which functions to maintain low cytosolic Ca²⁺ concentrations by actively transporting cytosolic Ca²⁺ ions into the endoplasmic reticulum. In this study, we characterized the role of SERCA in allergen-activated mast cells using IgE-sensitized bone marrow-derived mast cells (BMMCs) treated with the SERCA activating compound, CDN1163, and simultaneously stimulated with allergen through FcεRI under stem cell factor (SCF) potentiation. Acute treatment with CDN1163 was found to attenuate early phase mast cell degranulation along with reactive oxygen species (ROS) production. Additionally, treatment with CDN1163 significantly reduced secretion of IL-6, IL-13, and CCL3, suggesting a role for SERCA in the late phase mast cell response. The protective effects of SERCA activation via CDN1163 treatment on the early and late phase mast cell response may be driven by the selective suppression of p38 MAPK signaling. Together, these findings implicate SERCA as an important regulator of the mast cell response to allergen and suggest SERCA activity may offer therapeutic potential targeting allergic pathologies, warranting further investigation.