EGR-1 and DUSP-1 are important negative regulators of pro-allergic responses in airway epithelium

The Circadian Rhythm Regulates the Hepato-ovarian Axis Linking Polycystic Ovary Syndrome and Non-alcoholic Fatty Liver Disease

This study aimed to identify shared gene expression related to circadian rhythm disruption in polycystic ovary syndrome (PCOS) and non-alcoholic fatty liver disease (NAFLD) to discover common diagnostic biomarkers. Visceral fat RNA samples were collected from 12 PCOS and 14 non-PCOS patients, a sample size representing the clinical situation and sufficient to capture PCOS gene expression profiles. Along with liver transcriptome profiles from NAFLD patients, these data were analyzed to identify crosstalk circadian rhythm-related genes (CRRGs) between the diseases. Single-sample and single-gene gene set enrichment analyses explored immune infiltration and pathways associated with CRRGs. Diagnostic biomarkers were identified using a random forest algorithm and validated through nomograms and a mouse model. Seven crosstalk CRRGs (FOS, ACHE, FOSB, EGR1, NR4A1, DUSP1, and EGR3) were associated with clinical features, immunoinflammatory microenvironment, and metabolic pathways in both diseases. EGR1, DUSP1, and NR4A1 were identified as diagnostic biomarkers, exhibiting robust diagnostic capacity (AUC = 0.7679 for PCOS, AUG = 0.9981 for NAFLD). Nomogram validation showed excellent calibration, and independent datasets confirmed their discriminatory ability (AUC = 0.6528 for PCOS, AUC = 0.8275 for NAFLD). Additionally, ceRNA networks and androgen receptor binding sites were identified, suggesting their regulatory roles. Mouse model validation confirmed significant downregulation of EGR1, DUSP1, and NR4A1 in liver tissues, consistent with sequencing data. This study identifies crosstalk CRRGs and diagnostic biomarkers shared between PCOS and NAFLD, highlighting their roles in immune and metabolic dysregulation. These biomarkers offer the potential for improving diagnosis and guiding targeted treatments for both diseases.

The nasal basal cell population shifts toward a diseased phenotype with impaired barrier formation capacity in allergic rhinitis

BACKGROUND

The integrity of the airway epithelium is guarded by the airway basal cells that serve as progenitor cells and restore wounds in case of injury. Basal cells are a heterogenous population, and specific changes in their behavior are associated with chronic barrier disruption-mechanisms that have not been studied in detail in allergic rhinitis (AR).

OBJECTIVE

We aimed to study basal cell subtypes in AR and healthy controls.

METHODS

Single-cell RNA sequencing (scRNA-Seq) of the nasal epithelium was performed on nonallergic and house dust mite-allergic AR patients to reveal basal cell diversity and to identify allergy-related alterations. Flow cytometry, immunofluorescence staining, and in vitro experiments using primary basal cells were performed to confirm phenotypic findings at the protein level and functionally.

RESULTS

The scRNA-Seq, flow cytometry, and immunofluorescence staining revealed that basal cells are abundantly and heterogeneously present in the nasal epithelium, suggesting specialized subtypes. The total basal cell fraction within the epithelium in AR is increased compared to controls. scRNA-Seq demonstrated that potentially beneficial basal cells are missing in AR epithelium, while an activated population of allergy-associated basal cells is more dominantly present. Furthermore, our in vitro proliferation, wound healing assay and air-liquid interface cultures show that AR-associated basal cells have altered progenitor capacity compared to nonallergic basal cells.

CONCLUSIONS

The nasal basal cell population is abundant and diverse, and it shifts toward a diseased state in AR. The absence of potentially protective subtypes and the rise of a proinflammatory population suggest that basal cells are important players in maintaining epithelial barrier defects in AR.

Induction of IL-10-producing type 2 innate lymphoid cells by allergen immunotherapy is associated with clinical response

The role of innate immune cells in allergen immunotherapy that confers immune tolerance to the sensitizing allergen is unclear. Here, we report a role of interleukin-10-producing type 2 innate lymphoid cells (IL-10⁺ ILC2s) in modulating grass-pollen allergy. We demonstrate that KLRG1⁺ but not KLRG1^- ILC2 produced IL-10 upon activation with IL-33 and retinoic acid. These cells attenuated Th responses and maintained epithelial cell integrity. IL-10⁺ KLRG1⁺ ILC2s were lower in patients with grass-pollen allergy when compared to healthy subjects. In a prospective, double-blind, placebo-controlled trial, we demonstrated that the competence of ILC2 to produce IL-10 was restored in patients who received grass-pollen sublingual immunotherapy. The underpinning mechanisms were associated with the modification of retinol metabolic pathway, cytokine-cytokine receptor interaction, and JAK-STAT signaling pathways in the ILCs. Altogether, our findings underscore the contribution of IL-10⁺ ILC2s in the disease-modifying effect by allergen immunotherapy.

Emerging Regulatory Roles of Dual-Specificity Phosphatases in Inflammatory Airway Disease

Inflammatory airway disease, such as asthma and chronic obstructive pulmonary disease (COPD), is a major health burden worldwide. These diseases cause large numbers of deaths each year due to airway obstruction, which is exacerbated by respiratory viral infection. The inflammatory response in the airway is mediated in part through the MAPK pathways: p38, JNK and ERK. These pathways also have roles in interferon production, viral replication, mucus production, and T cell responses, all of which are important processes in inflammatory airway disease. Dual-specificity phosphatases (DUSPs) are known to regulate the MAPKs, and roles for this family of proteins in the pathogenesis of airway disease are emerging. This review summarizes the function of DUSPs in regulation of cytokine expression, mucin production, and viral replication in the airway. The central role of DUSPs in T cell responses, including T cell activation, differentiation, and proliferation, will also be highlighted. In addition, the importance of this protein family in the lung, and the necessity of further investigation into their roles in airway disease, will be discussed.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

DUSP1 regulates apoptosis and cell migration, but not the JIP1-protected cytokine response, during Respiratory Syncytial Virus and Sendai Virus infection

The host antiviral response involves the induction of interferons and proinflammatory cytokines, but also the activation of cell death pathways, including apoptosis, to limit viral replication and spreading. This host defense is strictly regulated to eliminate the infection while limiting tissue damage that is associated with virus pathogenesis. Post-translational modifications, most notably phosphorylation, are key regulators of the antiviral defense implying an important role of protein phosphatases. Here, we investigated the role of the dual-specificity phosphatase 1 (DUSP1) in the host defense against human respiratory syncytial virus (RSV), a pathogenic virus of the Pneumoviridae family, and Sendai virus (SeV), a model virus being developed as a vector for anti-RSV vaccine. We found that DUSP1 is upregulated before being subjected to proteasomal degradation. DUSP1 does not inhibit the antiviral response, but negatively regulates virus-induced JNK/p38 MAPK phosphorylation. Interaction with the JNK-interacting protein 1 scaffold protein prevents dephosphorylation of JNK by DUSP1, likely explaining that AP-1 activation and downstream cytokine production are protected from DUSP1 inhibition. Importantly, DUSP1 promotes SeV-induced apoptosis and suppresses cell migration in RSV-infected cells. Collectively, our data unveils a previously unrecognized selective role of DUSP1 in the regulation of tissue damage and repair during infections by RSV and SeV.

Comparative analysis of dual specificity protein phosphatase genes 1, 2 and 5 in response to immune challenges in Japanese flounder Paralichthys olivaceus

Dual-specificity MAP kinase (MAPK) phosphatases (DUSPs) are well-established negative modulators in regulating MAPK signaling in mammalian cells and tissues. Our previous studies have shown the involvement of DUSP6 in regulating innate immunity in Japanese flounder Paralichthys olivaceus. In order to gain a better understanding of the role of DUSPs in fish innate immunity, in the present study we identified and characterized three additional DUSP genes including DUSP1, 2 and 5 in P. olivaceus. The three Japanese flounder DUSP proteins share common domain structures composed of a conserved N-terminal Rhodanase/CDC25 domain and a C-terminal catalytic phosphatase domain, while they show only less than 26% sequence identities, indicating that they may have different substrate selectivity. In addition, mRNA transcripts of all the three DUSP genes are detected in all examined Japanese flounder tissues; however, DUSP1 is dominantly expressed in spleen while DUSP2 and 5 are primarily expressed in skin. Furthermore, all the three DUSP genes are constitutively expressed in the Japanese flounder head kidney macrophages (HKMs) and peripheral blood leucocytes (PBLs) with unequal distribution patterns. Moreover, all the three DUSPs gene expression was induced differently in response to the LPS and double-stranded RNA mimic poly(I:C) stimulations both in the Japanese flounder HKMs and PBLs, suggesting an association of DUSPs with TLR signaling in fish. Taken together, the co-expression of various DUSPs members together with their different responses to the immune challenges indicate that the DUSP members may operate coordinately in regulating the MAPK-dependent immune responses in the Japanese flounder.

Effects of anticholinergic agent on miRNA profiles and transcriptomes in a murine model of allergic rhinitis

Anticholinergic agent, ipratropium bromide (IB) ameliorates symptoms of allergic rhinitis (AR) using neuroimmunologic mechanisms. However, the underlying molecular mechanism remains largely unclear. In the present study, 27 mice with AR induced by ovalbumin were randomly allocated to one of three groups: Model group, model group with IB treatment for 2 weeks, and model group with IB treatment for 4 weeks. Allergic symptoms were evaluated according to symptoms scores. Differentially expressed genes [microRNAs (miRNAs) and messenger RNAs (mRNAs)] of nasal mucosa were identified by microarray analysis. The expression levels of candidate genes were measured by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The data indicates that the symptoms scores in allergic mice were significantly reduced by IB treatment. In the nasal mucosa of allergic mice with IB treatment, 207 mRNAs and 87 miRNAs were differentially expressed, when compared with the sham group. IB treatment significantly downregulated the expression levels of interleukin-4Rα and prostaglandin D2 synthase, whereas the leukemia inhibitory factor, A20 and nuclear receptor subfamily 4, group A, member 1 expression levels were upregulated. Similarly, the expression levels of mmu-miR-124-3p/5p, −133b-5p, −133a-3p/5p, −384-3p, −181a-5p, −378a-5p and −3071-5p were significantly increased. RT-qPCR data further validated these mRNA and miRNA expression levels. Thus, IB treatment regulated expression of allergic immune-associated mRNAs and miRNAs of the nasal mucosa in allergic mice, which may be associated with ameliorated nasal allergic symptoms.

Regulation of early growth response 2 expression by secreted frizzled related protein 1

BACKGROUND

Secreted frizzled-related protein 1 (SFRP1) expression is down-regulated in a multitude of cancers, including breast cancer. Loss of Sfrp1 also exacerbates weight gain as well as inflammation. Additionally, loss of SFRP1 enhances TGF-β signaling and the downstream MAPK pathway. TGF-β has been shown to increase the expression of Early Growth Response 2 (EGR2), a transcription factor implicated in immune function in a wide variety of cell types. The work described here was initiated to determine whether SFRP1 modulation affects TGF-β mediated EGR2 expression in mammary tissues as well as macrophage polarization.

METHODS

Real-time PCR analysis was performed to examine EGR2 expression in human and murine mammary epithelial cells and tissues in response to SFRP1 modulation. Chemical inhibition was employed to investigate the roles TGF-β and MAPK signaling play in the control of EGR2 expression in response to SFRP1 loss. Primary murine macrophages were isolated from Sfrp1^-/- mice and stimulated to become either M1 or M2 macrophages, treated with recombinant SFRP1, and real-time PCR was used to measure the expression of murine specific M1/M2 markers [Egr2 (M2) and Gpr18 (M1)]. Immunohistochemical analysis was used to measure the expression of human specific M1/M2 markers [CD163 (M2) and HLA-DRA (M2)] in response to rSFRP1 treatment in human mammary explant tissue.

RESULTS

Knockdown of SFRP1 expression increases the expression of EGR2 mRNA in human mammary epithelial cells and addition of rSFRP1 decreases the expression of EGR2 when added to explant mammary gland tissues. Chemical inhibition of both TGF-β and MAPK signaling in Sfrp1^-/- or knockdown mammary epithelial cells results in decreased expression of EGR2. Stimulated murine macrophages obtained from Sfrp1^-/- mice and treated with rSFRP1 exhibit a reduction in Egr2 expression and an increase in Gpr18 mRNA expression. Human mammary explant tissue treated with rSFRP1 decreases CD163 protein expression whereas there was no effect on the expression of HLA-DRA.

CONCLUSIONS

Loss of SFRP1 likely contributes to tumor progression by altering the expression of a critical transcription factor in both the epithelium and the immune system.

Specific Induction of TSLP by the Viral RNA Analogue Poly(I:C) in Primary Epithelial Cells Derived from Nasal Polyps

Introduction

Chronic rhinosinusitis with nasal polyposis is an inflammatory disease that, although not directly linked to allergy, often displays a Th2-skewed inflammation characterized by elevated local IgE and IL-5 levels. The nasal cavity is constantly exposed to bacteria and viruses that may trigger epithelial inflammatory responses. To gain more insight into mechanisms by which such a biased inflammation might arise, we have investigated the epithelial expression of the Th2 skewing mediators (TSLP, IL-25, and IL-33) in relationship to disease and microbial triggers.

Methods

Epithelial cells were obtained from polyp tissues of nasal polyposis patients and from inferior turbinates of non-diseased controls. Cells were exposed to various TLR-specific triggers to study the effect on mRNA and protein expression level of TSLP, IL-25, and IL-33 and the potential regulatory mechanisms through the expression profile the transcription factors ATF-3, DUSP-1, EGR-1, and NFKB-1.

Results

The TLR3 agonist and viral analogue poly(I:C) induced TSLP mRNA 13.0 ± 3.1 fold (p < 0.05) and protein expression by 12.1 ± 2.3-fold (p < 0.05) higher in epithelium isolated from nasal polyposis patients than in epithelium form healthy controls. This enhanced induction of TSLP may be a consequence of a down-regulated expression of DUSP-1 in polyp epithelium.

Conclusion

The TLR3 induced expression of TSLP introduces a mechanism by which the Th2-skewed tissue environment might arise in nasal polyps and invites a further evaluation of the potential contribution of current or past viral infections to polyposis pathogenesis.