The IFN-γ-p38, ERK kinase axis exacerbates neutrophilic chronic rhinosinusitis by inducing the epithelial-to-mesenchymal transition

Intermittent hypoxia-reoxygenation-induced miRNAs inhibit expression of IRF and interferon genes but activate NF-κB and expression of pulmonary fibrosis markers in human small airway epithelial cells

AIM

Intermittent hypoxia-reoxygenation (H/R) has been demonstrated to be associated with aviation and various respiratory diseases, and hence it is of interest to unravel the regulatory mechanisms underlying the H/R-induced innate immune and inflammatory responses in both healthy and COPD-diseased human small airway epithelial cells (SAECs).

MAIN METHODS

The normal healthy and COPD-diseased SAECs (i.e., N-SAECs and D-SAECs) were purchased from PromoCell biotechnology company and respectively cultured under normoxia (21 % O2) or 12/12-h cycles of H/R (i.e., 1 % O2 and 21 % O2 alternately) for 6 days in total for 2D cultures and 21 days in total for the air-liquid interface 3D cultures, followed by qPCR analyses, miRNA fluorescence in situ hybridization, luciferase reporter assays, and immunofluorescence staining.

KEY FINDINGS

Human SAECs cultured under 12/12-h cycles of H/R showed dramatically increased expression of HIF1A and the H/R-inducible miRNAs miR-129-1-3p, miR-1290 and miR-193b-5p, with miR-129-1-3p and miR-193b-5p targeting and inhibiting IRF5 and IRF7 mRNAs, hence downregulating both the type I and II interferon genes in SAECs cultured under H/R. In addition, miR-129-1-3p, miR-1290 and miR-193b-5p all targeted and inhibited SOCS3 mRNA, hence upregulating transactivation of NF-κB and in turn inducing expression of the inflammatory chemokine genes and pulmonary fibrosis-associated marker genes.

SIGNIFICANCE

We show for the first time that intermittent H/R upregulates the NF-κB-induced proinflammatory and fibrosis marker genes whereas downregulates the IRF5/7-induced type I/II interferon expression in human SAECs through distinct HIF1A-inducible miRNAs miR-129-1-3p, miR-193b-5p and miR-1290, which may serve as promising therapeutic targets for airway inflammation and pulmonary fibrosis.

Targeting neutrophil dysfunction in acute lung injury: Insights from active components of Chinese medicine

BACKGROUNDS

Acute lung injury (ALI) is a lethal condition characterized by uncontrolled pulmonary inflammatory responses, with high morbidity and mortality rates that pose a significant threat to patient health. The persistent retention of neutrophils in lung tissue and subsequent inflammatory damage represents a primary mechanism underlying the early onset of ALI disorders. In recent years, pharmaceutical research targeting these pathological processes has garnered considerable attention. Traditional Chinese medicines (TCM) and their active ingredients, known for their safety and stability, show promising potential in treating ALI through their ability to modulate neutrophil function via multiple pathways.

PURPOSE

This review examines the mechanisms of neutrophil involvement in the pathogenesis of ALI, investigates potential therapeutic targets and pathways through which Chinese medicines and their active ingredients regulate neutrophil function, and provides a theoretical foundation for developing novel clinical treatment strategies.

METHODS

A comprehensive literature search was conducted using multiple databases, including Science Direct, PubMed, Google Scholar, and Web of Science. Search terms included 'lung injury,' 'acute lung injury,' 'inflammatory lung injury,' 'inflammation,' 'active ingredient,' 'herbal,' 'traditional Chinese medicine,' 'mechanism,' 'drug,' and 'neutrophils.' The selected literature was systematically categorized and analyzed.

RESULTS

Our review reveals that TCM and active ingredients influence neutrophil function through four primary mechanisms to impede ALI progression: 1) reduction of neutrophil-mediated uncontrolled inflammatory responses by suppressing neutrophil hyperactivation and inhibiting neutrophil migration and infiltration; 2) attenuation of lung tissue inflammatory damage by inhibiting neutrophil-produced cytotoxic substances, including elastase granules, neutrophil extracellular traps (NETs), and reactive oxygen species (ROS); 3) suppression of inflammatory responses by decreasing the secretion of neutrophil-derived cytokines, such as interleukin (IL) -1β, IL-6 and tumor necrosis factor-alpha (TNF-α); and 4) enhancement of neutrophil phagocytosis and accelerate the removal of apoptotic neutrophils to eliminate harmful pathogens and promote late-stage tissue repair. These findings demonstrate that Chinese medicines and their active ingredients exhibit significant therapeutic potential in ALI disorders through the modulation of neutrophil function, providing a robust theoretical framework for their clinical applications.

CONCLUSION

Traditional Chinese medicines and their active ingredients demonstrate significant anti-inflammatory efficacy through multiple mechanisms of neutrophil function regulation, showing considerable promise for the treatment of ALI with broad clinical applications.

IL-8 promotes pyroptosis through ERK pathway and mediates glucocorticoid resistance in chronic rhinosinusitis with nasal polyps

OBJECTIVE

This study seeks to elucidate the role and molecular mechanisms of IL-8 in nasal epithelial cell pyroptosis and its impact on glucocorticoid (GC) resistance.

METHODS

We assessed the expression of pyroptosis-related biomarkers and IL-8 in tissues and human nasal epithelial cells (hNECs) from both control and nasal polyp patients using western blot. Their localization was determined through immunohistochemistry and immunofluorescence. Cell death and cytotoxicity assay, electron microscopy, ELISA, and immunofluorescence were utilized to investigate IL-8-induced pyroptosis and GC resistance in hNECs, alongside the examination of the involved signaling pathways via western blot and immunofluorescence. In a murine model, hematoxylin-eosin staining and immunohistochemistry clarified relationship between pyroptosis and GC resistance.

RESULTS

IL-8 and pyroptotic biomarker expression were significantly higher in nasal polyp-derived tissues and hNECs compared to controls. IL-8 showed a positive correlation and co-localized with the pyroptotic biomarkers. IL-8 triggered pyroptosis in hNECs by activating the ERK signaling pathway, leading to increased IL-1β and IL-18 secretion. Moreover, IL-8-induced pyroptosis was found to contribute to GC resistance by affecting phosphorylation of GC receptor Ser211. Inhibition of pyroptotic proteins mitigated IL-8-induced GC resistance both in vitro and in vivo.

CONCLUSION

Elevated IL-8 facilitates pyroptosis via the ERK signaling pathway and plays a significant role in GC resistance in nasal polyps.

The Expression Levels of Transforming Growth Factor β1 and Tumor Necrosis Factor Receptor Associated Factor 6 in Allergic Rhinitis Patients and Their Potential Relationship with Epithelial - Mesenchymal Transition: A Pilot Prospective Observational Study

Objective

To study the role of transforming growth factor beta 1 (TGF-β1) and tumor necrosis factor receptor related factor 6 (TRAF6) in the progression of epithelial mesenchymal transformation (EMT) in allergic rhinitis (AR).

Methods

A total of 30 patients underwent nasal endoscopic surgery at our Hospital were selected for 15 patients in each group based on their allergy status. Inferior turbinate mucosa tissue was obtained and analyzed using immunohistochemical (IHC) tests, real-time quantitative PCR (qRT-PCR) detection, and Western blotting (WB) tests to measure TGF-β1, TRAF6, E-cadherin, Vimentin, and α-Smooth Muscle Actin (α-SMA) expression levels.

Results

The expression levels of TGF-β1, TRAF6, Vimentin, and α-SMA were significantly higher in the AR group compared to the control group as shown by IHC, qRT-PCR, and WB (P < 0.05). E-cadherin expression was significantly lower group than in the control group (P < 0.05). Protein expression of TGF-β1 showed significantly positive correlations with TRAF6 (r = 0.8188, P = 0.0002), α-SMA (r = 0.8076, P = 0.0003), and Vimentin (r = 0.6917, P = 0.0043). There was a significantly negative correlation between protein expression of TGF-β1 and E-cadherin (r = -0.8032, P = 0.0003). Protein expression of TRAF6 showed a significantly negative correlation with E-cadherin (r = -0.6405, P = 0.0101) but positive correlations with α-SMA (r = 0.5809, P = 0.0231) and Vimentin (r = 0.555, P = 0.0318).

Conclusion

TGF-β1, TRAF6, and EMT-related markers (Vimentin, α-SMA) were highly expressed in the nasal mucosa of AR patients. TGF-β1 and TRAF6 may be involved in the epithelial-mesenchymal transition in allergic rhinitis.

NRP1 antagonism as a novel therapeutic target in nasal polyps of patients with chronic rhinosinusitis

BACKGROUND

Neuropilin-1 (NRP1) is expressed on the surface epithelium of respiratory tract and immune cells, demonstrating its possible function in regulating the immune response in airway disease. However, its role in patient with chronic rhinosinusitis (CRS) remains unknown. This study aimed to elucidate the role of NRP1 in CRS with nasal polyps (CRSwNP).

METHODS

Sinonasal biopsy specimens were immunohistochemically stained to investigate NRP1 expression. Double immunofluorescence, immunoblotting, and real-time polymerase chain reaction were performed to evaluate NRP1 in primary human nasal epithelial cells (hNECs). An NRP1 inhibitor was administered to a murine nasal polyp (NP) model.

RESULTS

NRP1 was highly expressed in the epithelium in patients with CRSwNP compared to nasal tissue from controls and CRS without NP patients. NRP1 and vascular endothelial growth factor were upregulated in hNECs under hypoxia. Treatment with NRP1 inhibitor (EG00229) reduced the secretion of interleukin (IL)-1β, IL-6, IL-8, and IL-33 cytokines, as well as inducible nitric oxide synthase, cyclooxygenase-2, and prostaglandin E2 in hNECs. We found that NRP1 was highly expressed in the airway epithelium in the murine NP model. The group treated with the NRP1 inhibitor had significantly fewer nasal polypoid lesions and reduced accumulations of immune cells.

CONCLUSIONS

These findings reveal that NRP1 is upregulated in CRS and NP epithelium, and the inhibition of NRP1 may lead to a reduction in NP growth and immune cell infiltration. Our results suggest that NRP1 inhibition could be a novel possibility for treating nasal polyposis.

Investigation and Characterization of the RAS/RAF/MEK/ERK Pathway and Other Signaling Pathways in Chronic Sinusitis with Nasal Polyps

BACKGROUND

The clinical outcomes of drug treatments and surgical interventions for chronic sinusitis with nasal polyps (CRSwNPs) are suboptimal, and the high recurrence rate remains a significant challenge in clinical practice. Targeted therapies such as biologics provide new perspectives and directions for treating CRSwNP.

SUMMARY

With the continuous investigation of signaling pathways, RAS/RAF/MEK/ERK signaling pathway and other signaling pathways including Hippo, JAK-STAT, Wnt, TGF-β, PI3K, Notch, and NF-κB were confirmed to play an important role in the progression of CRSwNP. Among them, the abnormality of RAS/RAF/MEK/ERK signaling pathway is accompanied by the abnormality of this apoptotic component, which may provide new research directions for targeting the components of signaling pathways to mediate apoptosis.

KEY MESSAGES

Abnormalities in signaling pathways are particularly important in studying the pathogenesis and treatment of CRSwNP. Therefore, this review summarizes the ongoing investigation and characterization of RAS/RAF/MEK/ERK signaling pathway and other signaling pathways in CRSwNP, which provides constructive ideas and directions for improving the treatment of CRSwNP.

SIRT5 exacerbates eosinophilic chronic rhinosinusitis by promoting polarization of M2 macrophage

BACKGROUND

Previous studies implied that local M2 polarization of macrophage promoted mucosal edema and exacerbated TH2 type inflammation in chronic rhinosinusitis with nasal polyps (CRSwNP). However, the specific pathogenic role of M2 macrophages and the intrinsic regulators in the development of CRS remains elusive.

OBJECTIVE

We sought to investigate the regulatory role of SIRT5 in the polarization of M2 macrophages and its potential contribution to the development of CRSwNP.

METHODS

Real-time reverse transcription-quantitative PCR and Western blot analyses were performed to examine the expression levels of SIRT5 and markers of M2 macrophages in sinonasal mucosa samples obtained from both CRS and control groups. Wild-type and Sirt5-knockout mice were used to establish a nasal polyp model with TH2 inflammation and to investigate the effects of SIRT5 in macrophage on disease development. Furthermore, in vitro experiments were conducted to elucidate the regulatory role of SIRT5 in polarization of M2 macrophages.

RESULTS

Clinical investigations showed that SIRT5 was highly expressed and positively correlated with M2 macrophage markers in eosinophilic polyps. The expression of SIRT5 in M2 macrophages was found to contribute to the development of the disease, which was impaired in Sirt5-deficient mice. Mechanistically, SIRT5 was shown to enhance the alternative polarization of macrophages by promoting glutaminolysis.

CONCLUSIONS

SIRT5 plays a crucial role in promoting the development of CRSwNP by supporting alternative polarization of macrophages, thus providing a potential target for CRSwNP interventions.

E3 ubiquitin ligase NEDD4L inhibits epithelial-mesenchymal transition by suppressing the β-catenin/HIF-1α positive feedback loop in chronic rhinosinusitis with nasal polyps

Chronic rhinosinusitis with nasal polyp (CRSwNP) is a refractory inflammatory disease with epithelial-mesenchymal transition (EMT) as one of the key features. Since ubiquitin modification has been shown to regulate the EMT process in other diseases, targeting ubiquitin ligases may be a potential strategy for the treatment of CRSwNP. In this study we investigated whether certain E3 ubiquitin ligases could regulate the EMT process in CRSwNP, and whether these regulations could be the potential drug targets as well as the underlying mechanisms. After screening the potential drug target by bioinformatic analyses, the expression levels of three potential E3 ubiquitin ligases were compared among the control, eosinophilic nasal polyp (ENP) and non-eosinophilic nasal polyp (NENP) group in clinical samples, and the significant decrement of the expression level of NEDD4L was found. Then, IP-MS, bioinformatics and immunohistochemistry studies suggested that low NEDD4L expression may be associated with the EMT process. In human nasal epithelial cells (hNECs) and human nasal epithelial cell line RPMI 2650, knockdown of NEDD4L promoted EMT, while upregulating NEDD4L reversed this effect, suggesting that NEDD4L inhibited EMT in nasal epithelial cells. IP-MS and Co-IP studies revealed that NEDD4L mediated the degradation of DDR1. We demonstrated that NEDD4L inhibited the β-catenin/HIF-1α positive feedback loop either directly (degrading β-catenin and HIF-1α) or indirectly (mediating DDR1 degradation). These results were confirmed in a murine NP model in vivo. This study for the first time reveals the regulatory role of ubiquitin in the EMT process of nasal epithelial cells, and identifies a novel drug target NEDD4L, which has promising efficacy against both ENP and NENP by suppressing β-catenin/HIF-1α positive feedback loop.

Involvement of Glucosamine 6 Phosphate Isomerase 2 (GNPDA2) Overproduction in β-Amyloid- and Tau P301L-Driven Pathomechanisms

Alzheimer's disease (AD) is a neurodegenerative olfactory disorder affecting millions of people worldwide. Alterations in the hexosamine- or glucose-related pathways have been described through AD progression. Specifically, an alteration in glucosamine 6 phosphate isomerase 2 (GNPDA2) protein levels has been observed in olfactory areas of AD subjects. However, the biological role of GNPDA2 in neurodegeneration remains unknown. Using mass spectrometry, multiple GNPDA2 interactors were identified in human nasal epithelial cells (NECs) mainly involved in intraciliary transport. Moreover, GNPDA2 overexpression induced an increment in NEC proliferation rates, accompanied by transcriptomic alterations in Type II interferon signaling or cellular stress responses. In contrast, the presence of beta-amyloid or mutated Tau-P301L in GNPDA2-overexpressing NECs induced a slowdown in the proliferative capacity in parallel with a disruption in protein processing. The proteomic characterization of Tau-P301L transgenic zebrafish embryos demonstrated that GNPDA2 overexpression interfered with collagen biosynthesis and RNA/protein processing, without inducing additional changes in axonal outgrowth defects or neuronal cell death. In humans, a significant increase in serum GNPDA2 levels was observed across multiple neurological proteinopathies (AD, Lewy body dementia, progressive supranuclear palsy, mixed dementia and amyotrophic lateral sclerosis) (n = 215). These data shed new light on GNPDA2-dependent mechanisms associated with the neurodegenerative process beyond the hexosamine route.

Neutrophil extracellular traps promote ΔNp63+ basal cell hyperplasia in chronic rhinosinusitis

BACKGROUND

Neutrophil extracellular traps (NETs) are observed in chronic rhinosinusitis (CRS), although their role remains unclear.

OBJECTIVES

This study aimed to investigate the influence of NETs on the CRS epithelium.

METHODS

Forty-five sinonasal biopsy specimens were immunofluorescence-stained to identify NETs and p63+ basal stem cells. Investigators treated human nasal epithelial cells with NETs and studied them with immunofluorescence staining, Western blotting, and quantitative real-time PCR. NET inhibitors were administered to a murine neutrophilic nasal polyp model.

RESULTS

NETs existed in tissues in patients with CRS with nasal polyps, especially in noneosinophilic nasal polyp tissues. p63+ basal cell expression had a positive correlation with the release of NETs. NETs induced the expansion of Ki-67+p63+ cells. We found that ΔNp63, an isoform of p63, was mainly expressed in the nasal epithelium and controlled by NETs. Treatment with deoxyribonuclease (DNase) I or Sivelestat (NET inhibitors) prevented the overexpression of ΔNp63+ epithelial stem cells and reduced polyp formation.

CONCLUSIONS

These results reveal that NETs are implicated in CRS pathogenesis via basal cell hyperplasia. This study suggests a novel possibility of treating CRS by targeting NETs.

miR-200a-3p regulates epithelial-mesenchymal transition and inflammation in chronic rhinosinusitis with nasal polyps by targeting ZEB1 via ERK/p38 pathway

BACKGROUND

Several biological processes are regulated by miR-200a-3p, including cell proliferation, migration, and epithelial-mesenchymal transition (EMT). In this study we aimed to uncover the diagnostic value and molecular mechanisms of miR-200a-3p in chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODS

The expressions of miR-200a-3p were detected by quantitative real-time polymerase chain reaction (qRT-PCR), Zinc finger E-box binding homeobox 1 (ZEB1) levels were examined by qRT-PCR and immunofluorescence staining. The interaction between miR-200a-3p and ZEB1 was predicted by TargetScan Human 8.0 and confirmed by dual-luciferase reporter assays. In addition, the effect of miR-200a-3p and ZEB1 on EMT-related makers and inflammation cytokines was assessed by qRT-PCR and Western blotting in human nasal epithelial cells (hNEpCs) and primary human nasal mucosal epithelial cells (hNECs).

RESULTS

We found that miR-200a-3p was downregulated in non-eosinophilic and eosinophilic CRSwNP patients when compared with controls. The diagnostic value of miR-200a-3p in serum is reflected by the receiver operating characteristic curve and the 22-item Sino-Nasal Outcome Test. Bioinformatic analysis and luciferase reporter assay identified ZEB1 as a target of miR-200a-3p. ZEB1 was more highly expressed in CRSwNP than in controls. Furthermore, miR-200a-3p inhibitor or ZEB1 overexpression significantly suppressed the epithelial marker E-cadherin; promoted the activation of vimentin, α-spinal muscle atrophy, and N-cadherin; and aggravated inflammation in hNEpCs. Knockdown of ZEB1 significantly alleviated the cellular remodeling caused by miR-200a-3p inhibitor via the extracellular signal-regulated kinase (ERK)/p38 pathway in hNECs.

CONCLUSIONS

miR-200a-3p suppresses EMT and inflammation by regulating the expression of ZEB1 via the ERK/p38 pathway. Our study presents new ideas for protecting nasal epithelial cells from tissue remodeling and finding a possible target for disease.

Which are the best murine models to study Eosinophilic Chronic Rhinosinusitis? A contemporary review

OBJECTIVE

Mechanisms that lead to Eosinophilic Chronic Rhinosinusitis (ECRS) are not fully established in the literature. It is desirable to assess ECRS in a model that embraces most of the related events. This article reviewed the murine models for ECRS and compared them regarding eosinophilic polypoid formation.

METHODS

The authors reviewed the articles that included the terms "chronic rhinosinusitis" OR "chronic sinusitis" AND "animal model". We analyzed articles in English that evaluated both the number of polyps and the number of eosinophils in the sinus mucosa of mouse models.

RESULTS

We identified a total of 15 articles describing different models of ECRS that used BALB/c or C57BL/6 mice, and different triggers/stimulants such as Staphylococcus aureus Enterotoxin B (SEB) + Ovalbumin (OVA); House Dust Mite (HDM) ± Ovalbumin (OVA); and Aspergillus oryzae Protease (AP) + Ovalbumin (OVA). OVA associated with SEB was the commonest protocol to induce ECRS in both BALB/c and C57BL/6 mice, and it produced a robust response of eosinophilic nasal polyps in both. AP + OVA protocol also led to a good ECRS response. The other models were not considered adequate to produce eosinophilic polyps in mice.

CONCLUSION

In conclusion, OVA associated with SEB seems to produce the most robust eosinophilic sinonasal inflammation.

Down Regulation of EGF and AZGP1 Were Associated with Clinical Characteristics in Chronic Rhinosinusitis with Nasal Polyps: An Observation Study

Objective

The mechanisms underlying the chronic rhinosinusitis with nasal polyps (CRSwNP) remained unclear. This study aimed to identify differentially expressed genes (DEGs) in nasal polyps from CRSwNP patients compared to healthy controls and explore key genes and pathways associated with CRSwNP pathophysiology and prognosis.

Methods

Three datasets were obtained from the Gene Expression Omnibus database and the intersecting DEGs were identified in CRSwNP patients. Gene Ontology (GO) and protein-protein interaction (PPI) network analysis were applied to investigate the function of DEGs. Nasal specimens from 90 CRSwNP and 45 controls were further collected and qRT-PCR was applied to verify the mRNA expression of hub genes, and moreover, their association with tissue eosinophilia and clinical characteristics in CRSwNP were analyzed.

Results

Sixty-eight co-DEGs including 8 upregulated and 60 downregulated genes were identified and GO analyses identified the terms including positive regulation of ERK1 and ERK2 cascade, transforming growth factor beta receptor signaling pathway. PPI networks identified hub genes including EGF, ERBB4, AZGP1, CRISP3 and PIP which were validated to be significantly down-regulated in CRSwNP and showed well diagnostic prediction quality. In addition, lower mRNA expressions level of EGF and AZGP1 in eosinophilic CRSwNP compared with non-eosinophilic CRSwNP were found. Aberrant low expressions of EGF and AZGP1 protein in CRSwNP were identified, and there was good consistency between their mRNA expression level and protein relative expression level. Furthermore, the expressions of EGF and AZGP1 mRNA were significantly correlated with clinical severity parameters.

Conclusion

Integrated analysis revealed 68 co-DEGs between nasal polyps and controls and identified hub genes, of which EGF and AZGP1 expression was significantly downregulated in eosinophilic CRSwNP and correlated with disease severity. Downregulation of EGF and AZGP1 may contribute to epithelial barrier dysfunction and type 2 inflammation in CRSwNP, suggesting them as potential diagnostic biomarkers and therapeutic targets.

A multi-omics integrative approach unravels novel genes and pathways associated with senescence escape after targeted therapy in NRAS mutant melanoma

Therapy Induced Senescence (TIS) leads to sustained growth arrest of cancer cells. The associated cytostasis has been shown to be reversible and cells escaping senescence further enhance the aggressiveness of cancers. Chemicals specifically targeting senescent cells, so-called senolytics, constitute a promising avenue for improved cancer treatment in combination with targeted therapies. Understanding how cancer cells evade senescence is needed to optimise the clinical benefits of this therapeutic approach. Here we characterised the response of three different NRAS mutant melanoma cell lines to a combination of CDK4/6 and MEK inhibitors over 33 days. Transcriptomic data show that all cell lines trigger a senescence programme coupled with strong induction of interferons. Kinome profiling revealed the activation of Receptor Tyrosine Kinases (RTKs) and enriched downstream signaling of neurotrophin, ErbB and insulin pathways. Characterisation of the miRNA interactome associates miR-211-5p with resistant phenotypes. Finally, iCell-based integration of bulk and single-cell RNA-seq data identifies biological processes perturbed during senescence and predicts 90 new genes involved in its escape. Overall, our data associate insulin signaling with persistence of a senescent phenotype and suggest a new role for interferon gamma in senescence escape through the induction of EMT and the activation of ERK5 signaling.

A Decade of Pathogenesis Advances in Non-Type 2 Inflammatory Endotypes in Chronic Rhinosinusitis: 2012-2022

Chronic rhinosinusitis (CRS) is a heterogeneous disease characterized by localized inflammation of the upper airways. CRS includes two main phenotypes, namely, CRS with nasal polyps and CRS without nasal polyps. The phenotype-based classification method cannot reflect the pathological mechanism. The endotype-based classification method has been paid more and more attention by researchers. It is mainly divided into type 2 and non-type 2 endotypes. The mechanism driving the pathogenesis of non-type 2 inflammation is currently unknown. In this review, the PubMed and Web of Science databases were searched to conduct a critical analysis of representative literature works on the pathogenesis of non-type 2 inflammation in CRS published in the past decade. This review summarizes the latest evidence that may lead to the pathogenesis of non-type 2 inflammation. It is the main method that analyzing the pathogenesis from the perspective of immunology. Genomics and proteomics technique provide new approaches to the study of the pathogenesis. Due to differences in race, environment, geography, and living habits, there are differences in the occurrence of non-type 2 inflammation, which increase the difficulty of understanding the pathogenesis of non-type 2 inflammation in CRS. Studies have confirmed that non-type 2 endotype is more common in Asian patients. The emergence of overlap and unclassified endotypes has promoted the study of heterogeneity in CRS. In addition, as the source of inflammatory cells and the initiation site of the inflammatory response, microvessels and microlymphatic vessels in the nasal mucosal subepithelial tissue participate in the inflammatory response and tissue remodeling. It is uncertain whether CRS patients affect the risk of infection with SARS-CoV-2. In addition, the pathophysiological mechanism of non-type 2 CRS combined with COVID-19 remains to be further studied, and it is worth considering how to select the befitting biologics for CRS patients with non-type 2 inflammation.

The interplay of inflammation and remodeling in the pathogenesis of chronic rhinosinusitis: current understanding and future directions

Chronic rhinosinusitis (CRS), a common clinical condition characterized by persistent mucosal inflammation and tissue remodeling, has a complex pathogenesis that is intricately linked to innate and adaptive immunity. A number of studies have demonstrated that a variety of immune cells and cytokines that play a vital role in mediating inflammation in CRS are also involved in remodeling of the nasal mucosa and the cells as well as different cytokines involved in remodeling in CRS are also able to exert some influence on inflammation, even though the exact relationship between inflammation and remodeling in CRS has not yet been fully elucidated. In this review, the potential role of immune cells and cytokines in regulating inflammation and remodeling of CRS mucosa has been described, starting with the immune cells and cytokines that act together in inflammation and remodeling. The goal is to aid researchers in understanding intimate connection between inflammation and remodeling of CRS and to offer novel ideas for future research.

Pathogenesis of chronic rhinosinusitis with nasal polyp and a prominent T2 endotype

Chronic rhinosinusitis is a heterogenous and multifactorial disease, characterized by persistent inflammation of the nose and paranasal sinuses, which causes nasal obstruction, nasal discharge, facial pain, and smell disturbance. Chronic rhinosinusitis is divided into two phenotypes: chronic rhinosinusitis with nasal polyp and chronic rhinosinusitis without nasal polyp. Nasal polyps can be associated with many inflammatory cells including eosinophil cells, neutrophil cells, plasma cells, and lymphocytes. T2 endotype is characterized by the type-2 immune response and nasal polyps are associated with eosinophilic dominant infiltration. In contrast, in the T1 and T3 endotypes, chronic rhinosinusitis can be associated with neutrophilic dominant infiltration. In addition, there are mixed types of inflammation with different proportions of eosinophils-neutrophils in chronic rhinosinusitis. In the T2 endotype, there is an increase in the production of Th2 cytokines, including interleukin-4, interleukin-5, and interleukin-13, high levels of immunoglobulin-E in polyp tissue, and eosinophilia. Stimulation of Th2 cells, type-2 innate lymphoid cells, epithelial cell damage, Staphylococcus aureus enterotoxins, and autoimmune antibodies have important roles in the enhancement of Th2 cytokines and pathogenesis of chronic rhinosinusitis with nasal polyp. Monoclonal antibodies target type-2 inflammation, decrease nasal polyp size, and improve the clinical symptoms of CRSwNP patients. The present review will focus on factors involved in the pathogenesis of chronic rhinosinusitis and its treatment.

Epithelial cell dysfunction in chronic rhinosinusitis: the epithelial-mesenchymal transition

INTRODUCTION

Epithelial-mesenchymal transition (EMT) is a type of epithelial cell dysfunction, which is widely present in the nasal mucosa of patients with chronic rhinosinusitis (CRS), especially CRS with nasal polyps, and contributes to pathogenesis of the disease. EMT is mediated via complex mechanisms associated with multiple signaling pathways.

AREAS COVERED

We have summarized the underlying mechanisms and signaling pathways promoting EMT in CRS. Strategies or drugs/agents targeting the genes and pathways related to the regulation of EMT are also discussed for their potential use in the treatment of CRS and asthma. A literature search of studies published in English from 2000 to 2023 was conducted using the PubMed database, employing CRS, EMT, signaling, mechanisms, targeting agents/drugs, as individual or combinations of search terms.

EXPERT OPINION

EMT in nasal epithelium not only leads to epithelial cell dysfunction but also plays an important role in nasal tissue remodeling in CRS. A comprehensive understanding of the mechanisms underlying EMT and the development of drugs/agents targeting these mechanisms may provide new treatment strategies for CRS.

Inhibition of IL-4/STAT6/IRF4 signaling reduces the epithelial-mesenchymal transition in eosinophilic chronic rhinosinusitis with nasal polyps

BACKGROUND

Previous studies have shown that epithelial-to-mesenchymal transition (EMT) in nasal epithelial cells is critical for tissue remodeling of chronic rhinosinusitis with nasal polyps (CRSwNP). However, the precise mechanism underlying the EMT remains poorly understood. This study aimed to investigate the role of interleukin-4 (IL-4)/signal transducer and activator of transcription 6 (STAT6)/interferon regulatory factor 4 (IRF4) signaling pathway on EMT in eosinophilic CRSwNP.

METHODS

We performed quantitative real-time polymerase chain reaction, immunohistochemistry, immunofluorescent staining, and Western blotting to evaluate the expression of STAT6, IRF4, and EMT markers in sinonasal mucosal samples. Effects of IL-4-induced EMT were determined using primary human nasal epithelial cells (hNECs) from patients with eosinophilic CRSwNP. Wound scratch assay, cell morphology, Western blotting, and immunofluorescence cytochemistry were performed to evaluate EMT, and EMT-related markers. Next, human THP-1 monocytic cells were stimulated by phorbolate-12-myristate-13-acetate to differentiate into M0 and were subsequently polarized into M1 with lipopolysaccharide and interferon-γ, M2 with IL-4. The markers of the macrophage phenotype were assessed by Western blotting. The co-culture system was built to explore the interaction between macrophages (THP-1 cells) and hNECs. After co-culture with M2 macrophages, EMT-related markers of primary hNECs were evaluated by immunofluorescence cytochemistry and Western blotting. Enzymelinked immunosorbent assays were used to detect transforming growth factor beta 1 (TGF-β1) in THP-1-derived supernatants.

RESULTS

STAT6 and IRF4 mRNA and protein expression were significantly upregulated in both eosinophilic and noneosinophilic nasal polyps compared with control tissues. The expression of STAT6 and IRF4 in eosinophilic nasal polyps was higher than those in noneosinophilic nasal polyps. STAT6 and IRF4 were not only expressed in epithelial cells but also in macrophages. The number of STAT6⁺CD68⁺ cells and IRF4⁺CD68⁺ cells in eosinophilic nasal polyps was higher than those in noneosinophilic nasal polyps and control tissues. EMT was enhanced in eosinophilic CRSwNP compared to the healthy controls and noneosinophilic CRSwNP. IL-4-stimulated human nasal epithelial cells exhibited EMT characteristics. The hNECs co-cultured with M2 macrophages demonstrated high levels of EMT-related markers. The TGF-β1 level was significantly induced by IL-4 and elevated (M2) rather than control macrophages. The inhibition of STAT6 by AS1517499 reduced the expression of IRF4 in epithelial cells and macrophages and counteracted IL-4-induced EMT in epithelial cells.

CONCLUSION

In eosinophilic nasal polyps, IL-4 induces STAT6 signaling to upregulate IRF4 expression in epithelial cells and macrophages. IL-4 promotes EMT of hNECs through the STAT6/IRF4 signaling pathway. IL-4-induced M2 macrophages enhanced EMT of hNECs. Inhibition of STAT6 can downregulate the expression of IRF4 and suppress the EMT process, thus providing a new strategy for the treatment of nasal polyps.

Protein stabilization of ITF2 by NF-κB prevents colitis-associated cancer development

Chronic colonic inflammation is a feature of cancer and is strongly associated with tumorigenesis, but its underlying molecular mechanisms remain poorly understood. Inflammatory conditions increased ITF2 and p65 expression both ex vivo and in vivo, and ITF2 and p65 showed positive correlations. p65 overexpression stabilized ITF2 protein levels by interfering with the binding of Parkin to ITF2. More specifically, the C-terminus of p65 binds to the N-terminus of ITF2 and inhibits ubiquitination, thereby promoting ITF2 stabilization. Parkin acts as a E3 ubiquitin ligase for ITF2 ubiquitination. Intestinal epithelial-specific deletion of ITF2 facilitated nuclear translocation of p65 and thus increased colitis-associated cancer tumorigenesis, which was mediated by Azoxymethane/Dextran sulfate sodium or dextran sulfate sodium. Upregulated ITF2 expression was lost in carcinoma tissues of colitis-associated cancer patients, whereas p65 expression much more increased in both dysplastic and carcinoma regions. Therefore, these findings indicate a critical role for ITF2 in the repression of colitis-associated cancer progression and ITF2 would be an attractive target against inflammatory diseases including colitis-associated cancer.

The role of interleukin 36γ in the epithelial-mesenchymal transition process of chronic rhinosinusitis: A pilot study

PURPOSE

Epithelial-mesenchymal transition (EMT) is an important characteristic in the remodelling of chronic rhinosinusitis with nasal polyps (CRSwNP). IL-36γ and fibroblast activation protein (FAP) may exacerbate remodelling in CRS. Here, we aimed to determine whether IL-36γ and FAP expression are associated with EMT and may be a predictor for CRSwNP prognosis.

METHODS

Fifty-two non-Eos CRSwNP patients and 12 control patients were obtained and were followed up for more than 1 year after surgery. IL-36γ, FAP and EMT markers expression were evaluated by real-time polymerase chain reaction and western blot. Masson trichrome staining was adopted to assess tissue fibrotic changes. Furthermore, the soluble form of IL-36γ and FAP in nasal secretions was detected by ELISA.

RESULTS

While basal expression of E-cadherin decreased, the expression of IL-36γ, vimentin and FAP increased in nasal polyps. In well-prognosis patients, the expression of IL-36γ, vimentin and FAP were significantly decreased than in poor-prognosis patients, while the protein expression of E-cadherin was increased. The protein expression of IL-36γ was notably increased in recurrent nasal polyps than in preoperation specimens. A positive relationship between IL-36γ and FAP expression, a negative relationship between IL-36γ and E-cad expression was noted. The soluble form of IL-36γ and FAP increased during the development of non-Eos CRSwNP, with the highest level in poor-prognosis patients after surgery.

CONCLUSION

Non-Eos CRSwNP have partially undergone EMT under baseline conditions. IL-36γ and FAP expression were related with EMT, the soluble form of IL-36γ and FAP in nasal secretions may predict the prognosis of patients.

Harnessing epithelial-mesenchymal plasticity to boost cancer immunotherapy

Immune checkpoint blockade (ICB) therapy is a powerful option for cancer treatment. Despite demonstrable progress, most patients fail to respond or achieve durable responses due to primary or acquired ICB resistance. Recently, tumor epithelial-to-mesenchymal plasticity (EMP) was identified as a critical determinant in regulating immune escape and immunotherapy resistance in cancer. In this review, we summarize the emerging role of tumor EMP in ICB resistance and the tumor-intrinsic or extrinsic mechanisms by which tumors exploit EMP to achieve immunosuppression and immune escape. We discuss strategies to modulate tumor EMP to alleviate immune resistance and to enhance the efficiency of ICB therapy. Our discussion provides new prospects to enhance the ICB response for therapeutic gain in cancer patients.

Role of Nasal Fibroblasts in Airway Remodeling of Chronic Rhinosinusitis: The Modulating Functions Reexamined

Chronic rhinosinusitis (CRS) is a multifactorial inflammatory disease of the nose and sinuses that affects more than 10% of the adult population worldwide. Currently, CRS is classified into endotypes according to the inflammatory response (Th1, Th2, and Th17) or the distribution of immune cells in the mucosa (eosinophilic and non-eosinophilic). CRS induces mucosal tissue remodeling. Extracellular matrix (ECM) accumulation, fibrin deposition, edema, immune cell infiltration, and angiogenesis are observed in the stromal region. Conversely, epithelial-to-mesenchymal transition (EMT), goblet cell hyperplasia, and increased epithelial permeability, hyperplasia, and metaplasia are found in the epithelium. Fibroblasts synthesize collagen and ECM, which create a structural skeleton of tissue and play an important role in the wound-healing process. This review discusses recent knowledge regarding the modulation of tissue remodeling by nasal fibroblasts in CRS.

TNF-α Regulates the Glucocorticoid Receptor Alpha Expression in Human Nasal Epithelial Cells Via p65-NF-κb and p38-MAPK Signaling Pathways

Background

Tumor necrosis factor (TNF)-α induces changes in the glucocorticoid receptor (GR) isoforms' expression in human nasal epithelial cells (HNECs) in chronic rhinosinusitis (CRS).

Objective

However, the underlying mechanism of TNF-α induced GR isoforms' expression in HNECs remains unclear. Here, we explored changes in inflammatory cytokines and glucocorticoid receptor alpha isoform (GRα) expression in HNECs.

Materials and Methods

To explore the expression of TNF-α in nasal polyps and nasal mucosa of CRS, fluorescence immunohistochemical analysis was employed. To investigate changes in inflammatory cytokines and GRα expression in HNECs, RT-PCR and western blotting were performed following the cells' incubation with TNF-α. Cells were pretreated with the nuclear factor-κB gene binding (NF-κB) inhibitor QNZ, the p38 inhibitor SB203580, and dexamethasone for one hour, then a TNF-α. Western blotting, RT-PCR, and immunofluorescence had been utilized for the cells' analysis and the ANOVA for the data analysis.

Results

The TNF-α fluorescence intensity was mainly distributed in nasal epithelial cells of nasal tissues. TNF-α prominently inhibited the expression of GRα mRNA from 6 to 24 h in HNECs. GRα protein was decreased from 12 to 24 h. Treatment with QNZ, SB203580, or dexamethasone inhibited the TNF-α and interleukin (IL)-6 mRNA expression and increased the GRα levels.

Conclusion

TNF-α induced changes in the GR isoforms' expression in HNECs, and it was mediated through p65-NF-κB and p38-MAPK signal transduction pathways, which could be considered a promising neutrophilic CRS treatment.

MiR-302a Regenerates Human Corneal Endothelial Cells against IFN-γ-Induced Cell Death

Damage to human corneal endothelial cells (hCECs) leads to bullous keratopathy because these cells cannot be regenerated in vivo. In this study, we investigated the protective role of microRNA (miR)-302a against interferon-γ (IFN-γ)-induced senescence and cell death of hCECs. Cultured hCECs were transfected with miR-302a and treated with IFN-γ (20 ng/mL) to evaluate the protective effect of miR-302a on IFN-γ-induced cell death. Senescence was evaluated by the senescence-associated β-galactosidase (SA-β-gal) assay, and the secretion of senescence-associated secretory phenotype (SASP) factors was analyzed. Mitochondrial function and endoplasmic reticulum (ER) stress were assessed. We revealed that miR-302a enhanced the cell viability and proliferation of hCECs and that IFN-γ increased the cell size, the number of SA-β-gal-positive cells, and SASP factors, and arrested the cell cycle, which was eliminated by miR-302a. miR-302a ameliorated mitochondrial oxidative stress and ER stress levels which were induced by IFN-γ. IFN-γ decreased the mitochondrial membrane potential and promoted autophagy, which was eliminated by miR-302a. The in vivo study showed that regeneration of rat CECs was promoted in the miR-302a group by inhibiting IFN-γ and enhancing mitochondrial function. In conclusion, miR-302a eliminated IFN-γ-induced senescence and cellular damage by regulating the oxidative and ER stress, and promoting the proliferation of CECs. Therefore, miR-302a may be a therapeutic option to protect hCECs against IFN-γ-induced stress.

Epidermal growth factor activates a hypoxia-inducible factor 1α-microRNA-21 axis to inhibit aquaporin 4 in chronic rhinosinusitis

The pathogenesis of chronic rhinosinusitis (CRS) is largely unknown, but accumulating evidence supports the role of the airway epithelium in its pathophysiology. In our study here, we evaluated whether epidermal growth factor (EGF) regulates a hypoxia-inducible factor 1α (HIF-1α)-microRNA-21 (miR-21)-aquaporin 4 (AQP4) axis in nasal epithelial cells from CRS patients. We found that, compared with normal sinus mucosa, EGF, HIF-1α, and miR-21 were upregulated and AQP4 was downregulated in sinus mucosa from patients with CRS and in a CRS mouse model. It was established that EGF upregulated HIF-1α and miR-21 expression, that HIF-1α regulated miR-21 transcription, and that the AQP4 gene was a target of miR-21. Knockdown of EGF and HIF-1α mRNAs and of miR-21, or overexpression of AQP4 mRNA, inhibited proliferation and promoted apoptosis of hypoxia-exposed human nasal epithelial cells, effects that were associated with reduced levels of α-SMA, fibronectin, and vimentin, as well as promoted caspase-3 activity and E-cadherin levels. In the mouse CRS model, EGF elevation increased in vivo production of inflammatory IL-4 and IFN-γ to promote CRS, which was reversed by AQP4 elevation. Collectively, EGF upregulates HIF-1α and miR-21 expression to inhibit AQP4 expression, thereby promoting the proliferation of nasal epithelial cells and the development of CRS.

Carnosine Synthase 1 Contributes to Interferon Gamma-Induced Arginine Depletion via Mitogen-activated Protein Kinase 11 Signaling in Bovine Mammary Epithelial Cells

Arginine is one of the host semiessential amino acids with diverse biological activities, and arginine depletion is associated with the incidence of many diseases. Arginine depletion induced by diet-derived interferon gamma (IFN-γ) leads to malignant transformation and impaired milk quality in healthy lactating bovine mammary epithelial cells (BMECs). However, the molecular mechanism of IFN-γ-induced arginine depletion is unclear. In this study, the BMEC cell line, mammary alveolar cells-large T antigen cells (MAC-T), was stimulated with IFN-γ (10 ng/mL) for 24 h, and cellular arginine and ornithine quantified by liquid chromatography-tandem mass spectrometry. Carnosine synthase 1 (CARNS1) was identified from RNA-seq data, CARNS1 knockdown was achieved using an shRNA interfering plasmid. The expression levels of CARNS1, argininosuccinate synthetase 1 (ASS1), mitogen-activated protein kinase 11 (p38 MAPK), and phosphorylated (p)-p38, and their cognate genes, were analyzed by Western blotting and real-time quantitative polymerase chain reaction. The results showed that IFN-γ inhibited the biosynthesis of arginine, but enhanced its catalysis via disruption of key enzymes involved in arginine metabolism. IFN-γ also inhibited the expression of CARNS1, ASS1, and cationic amino acid transporter 1, while activating the expression and phosphorylation of p38. However, knockdown of CARNS1 reduced arginine level and ASS1 expression and block of either the IFN-γ receptor IFN-γ receptor 2 or p38 relieved both the expression of Carnosine synthase 1 (CARNS1) and ASS1. In summary, these results indicate that IFN-γ induced arginine depletion through inhibition of CARNS1 signaling via activation of p38 in BMECs. These findings provide a novel insight for IFN-γ-related disease control strategies in dairy cows.

TIM-4 in macrophages contributes to nasal polyp formation through the TGF-β1–mediated epithelial to mesenchymal transition in nasal epithelial cells

Chronic rhinosinusitis with nasal polyps (CRSwNP) is caused by prolonged inflammation of the paranasal sinus mucosa. The epithelial to mesenchymal transition (EMT) is involved in the occurrence and development of CRSwNP. The T-cell immunoglobulin domain and the mucin domain 4 (TIM-4) is closely related to chronic inflammation, but its mechanism in CRSwNP is poorly understood. In our study, we found that TIM-4 was increased in the sinonasal mucosa of CRSwNP patients and, especially, in macrophages. TIM-4 was positively correlated with α-SMA but negatively correlated with E-cadherin in CRS. Moreover, we confirmed that TIM-4 was positively correlated with the clinical parameters of the Lund-Mackay and Lund-Kennedy scores. In the NP mouse model, administration of TIM-4 neutralizing antibody significantly reduced the polypoid lesions and inhibited the EMT process. TIM-4 activation by stimulating with tissue extracts of CRSwNP led to a significant increase of TGF-β1 expression in macrophages in vitro. Furthermore, coculture of macrophages and human nasal epithelial cells (hNECs) results suggested that the overexpression of TIM-4 in macrophages made a contribution to the EMT process in hNECs. Mechanistically, TIM-4 upregulated TGF-β1 expression in macrophages via the ROS/p38 MAPK/Egr-1 pathway. In conclusion, TIM-4 contributes to the EMT process and aggravates the development of CRSwNP by facilitating the production of TGF-β1 in macrophages. Inhibition of TIM-4 expression suppresses nasal polyp formation, which might provide a new therapeutic approach for CRSwNP.

Therapeutic Strategies of Biologics in Chronic Rhinosinusitis: Current Options and Future Targets

Chronic rhinosinusitis is a chronic inflammatory disease of the upper airways, for which treatment options include medical or surgical therapy. However, there are limitations to conservative treatment strategies, such as the relapse of nasal polyps. In this review, we discuss the rising role of biomolecular mechanisms associated with various biologics that have been approved or are undergoing clinical trials to treat chronic rhinosinusitis. We also highlight the potential molecular therapeutic targets for managing and treating chronic rhinosinusitis.

DEP-induced ZEB2 promotes nasal polyp formation via epithelial-to-mesenchymal transition

BACKGROUND

Diesel exhaust particles (DEPs) are associated with the prevalence and exacerbation of allergic respiratory diseases, including allergic rhinitis and allergic asthma. However, DEP-induced mechanistic pathways promoting upper airway disease and their clinical implications remain unclear.

OBJECTIVE

We sought to investigate the mechanisms by which DEP exposure contributes to nasal polyposis using human-derived epithelial cells and a murine nasal polyp (NP) model.

METHODS

Gene set enrichment and weighted gene coexpression network analyses were performed. Cytotoxicity, epithelial-to-mesenchymal transition (EMT) markers, and nasal polyposis were assessed. Effects of DEP exposure on EMT were determined using epithelial cells from normal people or patients with chronic rhinosinusitis with or without NPs. BALB/c mice were exposed to DEP through either a nose-only exposure system or nasal instillation, with or without house dust mite, followed by zinc finger E-box-binding homeobox (ZEB)2 small hairpin RNA delivery.

RESULTS

Bioinformatics analyses revealed that DEP exposure triggered EMT features in airway epithelial cells. Similarly, DEP-exposed human nasal epithelial cells exhibited EMT characteristics, which were dependent on ZEB2 expression. Human nasal epithelial cells derived from patients with chronic rhinosinusitis presented more prominent EMT features after DEP treatment, when compared with those from control subjects and patients with NPs. Coexposure to DEP and house dust mite synergistically increased the number of NPs, epithelial disruptions, and ZEB2 expression. Most importantly, ZEB2 inhibition prevented DEP-induced EMT, thereby alleviating NP formation in mice.

CONCLUSIONS

Our data show that DEP facilitated NP formation, possibly via the promotion of ZEB2-induced EMT. ZEB2 may be a therapeutic target for DEP-induced epithelial damage and related airway diseases, including NPs.

Tumor Secretome to Adoptive Cellular Immunotherapy: Reduce Me Before I Make You My Partner

Adoptive cellular immunotherapy using chimeric antigen receptor (CAR)-modified T cells and Natural Killer (NK) cells are common immune cell sources administered to treat cancer patients. In detail, whereas CAR-T cells induce outstanding responses in a subset of hematological malignancies, responses are much more deficient in solid tumors. Moreover, NK cells have not shown remarkable results up to date. In general, immune cells present high plasticity to change their activity and phenotype depending on the stimuli they receive from molecules secreted in the tumor microenvironment (TME). Consequently, immune cells will also secrete molecules that will shape the activities of other neighboring immune and tumor cells. Specifically, NK cells can polarize to activities as diverse as angiogenic ones instead of their killer activity. In addition, tumor cell phagocytosis by macrophages, which is required to remove dying tumor cells after the attack of NK cells or CAR-T cells, can be avoided in the TME. In addition, chemotherapy or radiotherapy treatments can induce senescence in tumor cells modifying their secretome to a known as “senescence-associated secretory phenotype” (SASP) that will also impact the immune response. Whereas the SASP initially attracts immune cells to eliminate senescent tumor cells, at high numbers of senescent cells, the SASP becomes detrimental, impacting negatively in the immune response. Last, CAR-T cells are an attractive option to overcome these events. Here, we review how molecules secreted in the TME by either tumor cells or even by immune cells impact the anti-tumor activity of surrounding immune cells.

Eosinophils Correlate with Epithelial-Mesenchymal Transition in Chronic Rhinosinusitis with Nasal Polyps

INTRODUCTION

Chronic inflammation and tissue remodeling always occur together in chronic rhinosinusitis (CRS). Epithelial-mesenchymal transition (EMT) plays a critical role in airway remodeling.

OBJECTIVE

Changes of epithelial cells in sinus mucosa in different subtypes of CRS, especially in eosinophilic chronic rhinosinusitis with nasal polyps, and the role of EMT and eosinophils (EOS) in airway remodeling are still unknown.

METHODS

We included 85 patients in this study. They were divided into 4 groups: a normal control (NC) group, a chronic rhinosinusitis without nasal polyps (CRSsNP) group, an eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) group, and a noneosinophilic chronic rhinosinusitis with nasal polyps (non-ECRSwNP) group. Clinical data were all collected and analyzed. Standard hematoxylin and eosin staining, immunohistochemical staining, and 2-color immunofluorescence staining were performed. Biomarkers of EMT, epithelial cadherin, and vimentin were labeled. The immunohistochemistry results of each group were counted and statistically analyzed.

RESULTS AND CONCLUSION

E-cadherin was downregulated, and vimentin was upregulated in epithelial tissue from the ECRSwNP group, compared with that from the control group and the other groups. The number of vimentin-expressing epithelial cells correlated with sinus CT imaging Lund-Mackay scores (r = 0.560, p < 0.001). Moreover, expression levels of vimentin in the epithelium were associated with numbers of infiltrating EOS in tissues (r = 0.710, p < 0.001) and the peripheral blood EOS ratio (r = 0.594, p < 0.001). EMT occurred in patients with CRSwNP, especially in those with ECRSwNP. Epithelial reprogramming correlates with eosinophil infiltration and disease severity. Eosinophils contributed to impairment of epithelial function and promoted EMT in CRSwNP.

Bone morphogenetic protein-2 as a novel biomarker for refractory chronic rhinosinusitis with nasal polyps

BACKGROUND

Bone morphogenetic proteins (BMPs), which are members of the TGF-β superfamily, regulate bone remodeling by stimulating osteoblasts and osteoclasts. Although the association between osteitis and poor surgical outcomes is well known in patients with chronic rhinosinusitis (CRS), BMPs have not been fully investigated as potential biomarkers for the prognosis of CRS.

OBJECTIVE

Our aim was to investigate the role of BMPs in osteitis in patients with CRS with nasal polyps (NPs) (CRSwNPs), as well as associations between BMPs and inflammatory markers in sinonasal tissues from patients with CRSwNP.

METHODS

We investigated the expression of 6 BMPs (BMP-2, BMP-4, BMP-6, BMP-7, BMP-9, and BMP-10) and their cellular origins in NPs of human subjects by using immunohistochemistry and ELISA of NP tissues. Exploratory factor analysis was performed to identify associations between BMPs and inflammatory markers. Air-liquid interface cell culture of human nasal epithelial cells was performed to evaluate the induction of the epithelial-mesenchymal transition by BMPs.

RESULTS

Of the 6 BMPs studied, BMP-2 and BMP-7 were associated with refractoriness. Only BMP-2 concentrations were higher in patients with severe osteitis and advanced disease extent according to the computed tomography findings. Eosinophils and some macrophages were identified as cellular sources of BMP-2 in immunofluorescence analysis. An in vitro experiment revealed that BMP-2 induced epithelial-mesenchymal transition in air-liquid interface-cultured human nasal epithelial cells, particularly in a T_H2 milieu.

CONCLUSION

BMP-2 could reflect the pathophysiology of mucosa and bone remodeling and may be a novel biomarker for refractory CRSwNP.

In Nasal Mucosal Secretions, Distinct IFN and IgA Responses Are Found in Severe and Mild SARS-CoV-2 Infection

Likely as in other viral respiratory diseases, SARS-CoV-2 elicit a local immune response, which includes production and releasing of both cytokines and secretory immunoglobulin (SIgA). Therefore, in this study, we investigated the levels of specific-SIgA for SARS-CoV-2 and cytokines in the airways mucosa 37 patients who were suspected of COVID-19. According to the RT-PCR results, the patients were separated into three groups: negative for COVID-19 and other viruses (NEGS, n = 5); negative for COVID-19 but positive for the presence of other viruses (OTHERS, n = 5); and the positive for COVID-19 (COVID-19, n = 27). Higher specific-SIgA for SARS-CoV-2, IFN-β, and IFN-γ were found in the COVID-19 group than in the other groups. Increased IL-12p70 levels were observed in OTHERS group as compared to COVID-19 group. When the COVID-19 group was sub stratified according to the illness severity, significant differences and correlations were found for the same parameters described above comparing severe COVID-19 to the mild COVID-19 group and other non-COVID-19 groups. For the first time, significant differences are shown in the airway's mucosa immune responses in different groups of patients with or without respiratory SARS-CoV-2 infection.

Advances in the Knowledge of the Underlying Airway Remodeling Mechanisms in Chronic Rhinosinusitis Based on the Endotypes: A Review

Chronic rhinosinusitis (CRS) is a chronic inflammatory condition of the nasal and paranasal sinus mucosa that affects up to 10% of the population worldwide. CRS is the most representative disease of the upper respiratory tract where airway remodeling occurs, including epithelial damage, thickening of the basement membrane, fibrosis, goblet cell hyperplasia, subepithelial edema, and osteitis. CRS is divided into two phenotypes according to the presence or absence of nasal polyps: CRS with nasal polyp (CRSwNP) and CRS without nasal polyps (CRSsNP). Based on the underlying pathophysiologic mechanism, CRS is also classified as eosinophilic CRS and non-eosinophilic CRS, owing to Type 2 T helper (Th2)-based inflammation and Type 1 T helper (Th1)/Type 17 T helper (Th17) skewed immune response, respectively. Differences in tissue remodeling in CRS are suggested to be based on the clinical phenotype and endotypes; this is because fibrosis is prominent in CRSsNP, whereas edematous changes occur in CRSwNP, especially in the eosinophilic type. This review aims to summarize the latest information on the different mechanisms of airway remodeling in CRS according to distinct endotypes.

Transient Receptor Potential Channel 6 Knockout Ameliorates Kidney Fibrosis by Inhibition of Epithelial-Mesenchymal Transition

Kidney fibrosis is generally confirmed to have a significant role in chronic kidney disease, resulting in end-stage kidney failure. Epithelial–mesenchymal transition (EMT) is an important molecular mechanism contributing to fibrosis. Tubular epithelial cells (TEC), the major component of kidney parenchyma, are vulnerable to different types of injuries and are a significant source of myofibroblast by EMT. Furthermore, TRPC6 knockout plays an anti-fibrotic role in ameliorating kidney damage. However, the relationship between TRPC6 and EMT is unknown. In this study, TRPC6^−/− and wild-type (WT) mice were subjected to a unilateral ureteric obstruction (UUO) operation. Primary TEC were treated with TGF-β1. Western blot and immunofluorescence data showed that fibrotic injuries alleviated with the inhibition of EMT in TRPC6^−/− mice compared to WT mice. The activation of AKT-mTOR and ERK1/2 pathways was down-regulated in the TRPC6^−/− mice, while the loss of Na⁺/K⁺-ATPase and APQ1 was partially recovered. We conclude that TRPC6 knockout may ameliorate kidney fibrosis by inhibition of EMT through down-regulating the AKT-mTOR and ERK1/2 pathways. This could contribute to the development of effective therapeutic strategies on chronic kidney diseases.

Epithelial-Mesenchymal Transition in Atopy: A Mini-Review

Atopic diseases, particularly atopic dermatitis (AD), asthma, and allergic rhinitis (AR) share a common pathogenesis of inflammation and barrier dysfunction. Epithelial to mesenchymal transition (EMT) is a process where epithelial cells take on a migratory mesenchymal phenotype and is essential for normal tissue repair and signal through multiple inflammatory pathways. However, while links between EMT and both asthma and AR have been demonstrated, as we outline in this mini-review, the literature investigating AD and EMT is far less well-elucidated. Furthermore, current studies on EMT and atopy are mostly animal models or ex vivo studies on cell cultures or tissue biopsies. The literature covered in this mini-review on EMT-related barrier dysfunction as a contributor to AD as well as the related (perhaps resultant) atopic diseases indicates a potential for therapeutic targeting and carry treatment implications for topical steroid use and environmental exposure assessments. Further research, particularly in vivo studies, may greatly advance the field and translate into benefit for patients and families.

Epithelial-to-mesenchymal transition in neutrophilic chronic rhinosinusitis

PURPOSE OF REVIEW

Barrier dysfunction, tissue fibrosis, and remodeling are essential processes of the pathophysiology of chronic rhinosinusitis (CRS). The role of epithelial-to-mesenchymal transition (EMT) has been assessed in various studies in CRS. In this review, we summarized the pathophysiologic mechanisms of EMT related to CRS, particularly neutrophilic CRS.

RECENT FINDINGS

Loss of epithelial characteristics due to EMT makes leaky epithelium, and transformed mesenchymal cells cause fibrosis and remodeling. Hypoxia, allergens (house dust mites), infections, and air pollutants were related to the pathogenesis of neutrophilic CRS, and these factors are known to induce barrier dysfunction and EMT in sinonasal epithelia. Some molecular pathways related to EMT have been recognized in CRS, including interferon-γ/p38/extracellular signal-regulated kinase, high-mobility group box 1/receptor of advanced glycosylation end-products, TGF-β1/SMAD, and Wnt/β-catenin-signaling pathways. Apart from, several microRNAs (miR-21, miR-761, and miR-30a-5p) have been identified to regulate EMT in CRS.

SUMMARY

EMT is considered to be an important pathogenesis mechanism for CRS. The factors cause EMT in CRS, and the associated molecular mechanisms are related to neutrophilic inflammation. Further studies on CRS endotype and/or phenotype are needed to clarify the implication of EMT on CRS pathogenesis.

Nasal Polyposis: Insights in Epithelial-Mesenchymal Transition and Differentiation of Polyp Mesenchymal Stem Cells

Chronic rhinosinusitis is a common inflammatory disease of paranasal sinuses, which causes rhinorrhea, nasal congestion, and hyposmia. The genetic predisposition or the exposure to irritants can sustain the inflammatory response and the development of nasal polyposis. Nasal polyps are benign and teardrop-shaped growths that project in the nasal cavities, and originate from the ethmoid sinuses. This inflammatory process is associated with high expression of IL-4, IL-5 and IL-13 and IgE. Antibodies targeting these cytokines or receptors represent a therapeutic strategy in the treatment of nasal polyposis in combination with corticosteroids. The molecular pathogenesis of nasal polyps in chronic rhinosinusitis (CRS) patients is associated with remodeling transition, a process in which epithelial cells lose their typical phenotype, acquiring a mesenchymal-like aspect. TGFβ/SMAD, ERK, and Wnt/β-catenin pathways are altered during the nasal tissue remodeling. miRNA and inhibitor molecules targeting these signaling pathways are able to interfere with the process; which could lead to alternative therapies. Nasal polyps are an alternative source of mesenchymal stem cells, which can be isolated from surgical biopsies. A molecular understanding of the biology of PO-MSCs will contribute to the delineating inflammatory process underlying the development of nasal polyps.

Evaluation of Neo-Osteogenesis in Eosinophilic Chronic Rhinosinusitis Using a Nasal Polyp Murine Model

Purpose

Osteitis refers to the development of new bone formation and remodeling of bone in chronic rhinosinusitis (CRS) patients; it is typically associated with eosinophilia, nasal polyps (NPs), and recalcitrant CRS. However, the roles of ossification in CRS with or without NPs remain unclear due to the lack of appropriate animal models. Thus, it is necessary to have a suitable animal model for greater advances in the understanding of CRS pathogenesis.

Methods

BALB/c mice were administered ovalbumin (OVA) and staphylococcal enterotoxin B (SEB). The numbers of osteoclasts and osteoblasts and bony changes were assessed. Micro computed tomography (micro-CT) scans were conducted to measure bone thickness. Immunofluorescence, immunohistochemistry, and quantitative polymerase chain reaction were performed to evaluate runt-related transcription factor 2 (RUNX2), osteonectin, interleukin (IL)-13, and RUNX2 downstream gene expression. Gene set enrichment analysis was performed in mucosal tissues from control and CRS patients. The effect of resveratrol was evaluated in terms of osteogenesis in a murine eosinophilic CRS NP model.

Results

The histopathologic changes showed markedly thickened bones with significant increase in osteoblast numbers in OVA/SEB-treated mice compared to the phosphate-buffered saline-treated mice. The structural changes in bone on micro-CT were consistent with the histopathological features. The expression of RUNX2 and IL-13 was increased by the administration of OVA/SEB and showed a positive correlation. RUNX2 expression mainly co-localized with osteoblasts. Bioinformatic analysis using human CRS transcriptome revealed that IL-13-induced bony changes via RUNX2. Treatment with resveratrol, a candidate drug against osteitis, diminished the expression of IL-13 and RUNX2, and the number of osteoblasts in OVA/SEB-treated mice.

Conclusions

In the present study, we found the histopathological and radiographic evidence of osteogenesis using a previously established murine eosinophilic CRS NP model. This animal model could provide new insights into the pathophysiology of neo-osteogenesis and provide a basis for developing new therapeutics.

Neutrophils as a Protagonist and Target in Chronic Rhinosinusitis

Neutrophils have traditionally been acknowledged as the first immune cells that are recruited to inflamed tissues during acute inflammation. By contrast, their importance in the context of chronic inflammation has been studied in less depth. Neutrophils can be recruited and are largely present in the nasal mucosa of patients with chronic rhinosinusitis (CRS) both in Asians and in Caucasians. Increased infiltration of neutrophils in patients with CRS has been linked to poor corticosteroid response and disease prognosis. Meanwhile, tissue neutrophils may possess specific phenotypic features distinguishing them from resting blood counterparts and are endowed with particular functions, such as cytokines and chemokines production, thus may contribute to the pathogenesis of CRS. This review aims to summarize our current understanding of the pathophysiologic mechanisms of CRS, with a focus on the roles of neutrophils. We discuss recruitment, function, and regulation of neutrophils in CRS and outline the potential therapeutic strategies targeting neutrophils.

Interleukin (IL)-13 and IL-17A contribute to neo-osteogenesis in chronic rhinosinusitis by inducing RUNX2

Background

There is increasing evidence supporting the impact of neoosteogenesis in the pathophysiology of chronic rhinosinusitis (CRS), especially in the recalcitrant group of patients. Runt-related transcription factor 2 (RUNX2), a member of the RUNX family, controls osteoblast differentiation and bone formation. However, the role and regulation of RUNX2 in CRS patients with neoosteogenesis remain unclear. The aim of the study is to determine the role of RUNX2 in neoosteogenesis of CRS patients.

Methods

Sinonasal bone and overlying mucosa samples were obtained from CRS patients with or without neoosteogenesis (n = 67) and healthy controls (n = 11). Double immunofluorescence, immunohistochemistry, and immunoblotting were used to evaluate RUNX2 expression in CRS patients with and without neoosteogenesis. In addition, the osteogenic activity of pro-inflammatory cytokines was examined by measuring alkaline phosphatase (ALP) activity and bone mineralisation in vitro.

Findings

RUNX2 was highly expressed in osteoblasts of CRS patients with neoosteogenesis compared with tissues from control subjects and those with CRS without neoosteogenesis. Mucosal extracts from CRS patients with neoosteogenesis showed increased RUNX2 expression and ALP activity in C2C12 cells, whereas those from patients without neoosteogenesis did not. Expression of interleukin (IL)-13 and IL-17A was upregulated in CRS patients with neoosteogenesis. ALP activity and Alizarin Red staining showed IL-13 and IL-17A dose-dependent osteoblast differentiation and mineralisation in vitro.

Interpretation

These findings suggested that IL-13- or IL-17A-induced RUNX2 contributed to new bone formation in CRS patients through its effect on the activity of osteoblasts. RUNX2 may be a novel target for preventing neoosteogenesis in CRS patients.