Human Nasal Epithelial Cells Research Articles

Interleukin-19 enhances eosinophil infiltration through upregulation of epithelium-derived RANTES expression via the ERK/NF-κB signalling pathway in patients with eosinophilic CRSwNP.

The recurrence rate of chronic rhinosinusitis with nasal polyps (CRSwNP) is positively correlated with eosinophil infiltration. Increased interleukin (IL)-19 and eosinophil chemokine RANTES levels have been reported in patients with CRSwNP. This study aimed to clarify the role of IL-19 in mediating RANTES expression and eosinophilic infiltration in eosinophilic CRSwNP (Eos CRSwNP). Nasal tissue samples were obtained from patients with CRSwNP and controls. The expression of IL-19, its receptors, ECP, and RANTES in tissues was investigated. Primary human nasal epithelial cells (HNECs) and nasal polyp tissue blocks were cultured, then stimulated by IL-19; ERK phosphorylation, NF-κB pathway activation, RANTES level, eosinophils migration and infiltration were detected using RT-qPCR, ELISA, western blotting, HE, immunohistochemistry, immunofluorescence staining, confocal microscopy, and transwell migration assay. The expression of IL-19 and its receptors (IL-20R1/IL-20R2), eosinophil cationic protein, and RANTES in nasal tissues from patients with Eos CRSwNP was significantly increased compared to that in non-Eos CRSwNP and control subjects. IL-19 co-localized with RANTES in nasal tissues and significantly elevated RANTES expression in HNECs. IL-19-blocking antibody and siRNA knockdown of IL-20R1 ameliorated the effect of IL-19 on RANTES secretion in HNECs. Moreover, IL-19-induced RANTES upregulation was associated with the activation of the ERK and NF-κB pathways. NF-κB activation was mediated by the ERK pathway in IL-19-treated HNECs, and IL-19 enhanced eosinophil infiltration in nasal polyp tissue blocks. Our findings indicate that IL-19 promotes RANTES expression via the ERK/NF-κB pathway in HNECs and is implicated in eosinophil infiltration in patients with Eos CRSwNP.

Three Artemisia pollens trigger the onset of allergic rhinitis via TLR4/MyD88 signaling pathway.

The prevalence of allergic rhinitis is high, making it a relatively common chronic condition. Countless patients suffer from seasonal Allergic rhinitis (AR). The objective of this investigation is to examine the potential involvement of common pollen allergens in seasonal allergic rhinitis, and study the proposed mechanism of Toll-like receptor 4 (TLR4)/Myeloid differentiation primary response gene 88 (MyD88) signaling pathway in the induction of AR. A mouse AR model (sensitized group) was constructed with pollen extracts and ovalbumin(OVA) of Artemisia annua (An), Artemisia argyi (Ar) and Artemisia Sieversiana (Si), and thereafter, AR symptom score was performed. After successful modeling, mouse serum and nasal mucosa tissues were extracted for subsequent experiments. The expression levels of immunoglobulin E (IgE), Interleukin (IL)-4, IL-5, IL-13 and Tumor Necrosis Factor-α (TNF-α) in serum were detected using Enzyme-linked immunosorbent assay (ELISA); Hematoxylin-eosin (H&E) staining methods were used to observe the pathological changes of the nasal mucosal tissue; Utilizing immunohistochemistry (IHC) staining, the expression levels of TLR4, MyD88 and Nuclear factor kappa B (NF-κB) p65 in mouse nasal mucosa were quantified; The mRNA and protein expression levels of TLR4, MyD88 and NF-κB p65 in nasal mucosa of sensitized mice were detected with Quantitative reverse transcription PCR (qRT-PCR) and Western Blot. Finally, the in vitro culture of Human nasal mucosal epithelial cells (HNEpC) cells was conducted, and cells were treated with 200µg/ml Artemisia annua pollen extractand OVA for 24h. Western Blot assay was used to detect the expression level of TLR4, MyD88 and NF-κB p65 proteins before and after HNEpC cells were treated with MyD88 inhibitor ST-2825. On the second day after AR stimulation, the mice showed obvious AR symptoms. H&E results showed that compared to the control group, the nasal mucosal tissue in the sensitized group was significantly more inflamed. Furthermore, ELISA assay showed increased expression levels of IgE, IL-4, IL-5, IL-13 and TNF-α in serum of mice induced by OVA and Artemisia annua pollen, Artemisia argyi pollen and Artemisia Sieversiana pollen than those of the control group. However, the expression level of IL-2 was lower than that of the control group (P < 0.05). Using Immunohistochemistry staining visually observed the expression levels of TLR4, MyD88 and NF-κB p65 in mouse nasal mucosa tissues and quantitatively analyzed. The expression levels of TLR4, MyD88 and NF-κB p65 in the sensitized group were higher than those in the control group, and the differences were statistically significant (P < 0.05). The results from qRT-PCR and Western Blot showed that the mRNA and protein expression levels of TLR4, MyD88 and NF-κB p65 in nasal mucosa of the sensitized group were significantly higher than those in the control group (P < 0.05). Finally, HNEpC cells were cultured in vitro and analyzed using Western Blot. The expression levels of TLR4, MyD88 and NF-κB p65 in OVA and An groups were significantly increased (P < 0.05). After ST-2825 treatment, TLR4 protein expression was significantly increased (P < 0.05) and MyD88 and NF-κB p65 protein expression were significantly decreased (P < 0.05). To sum up, the occurrence and development of AR induced by OVA and pollen of Artemisia annua, Artemisia argyi and Artemisia Sieversiana were related to TLR4/MyD88 signal pathway.

Luteolin Inhibits Lipopolysaccharide-Induced Inflammation and Epithelial–Mesenchymal Transition in Human Nasal Epithelial Cells

Chronic sinusitis is a persistent inflammatory condition needing better treatment options with fewer side effects to reduce recurrence. Luteolin, a flavonoid found in various plants, exhibits anti-inflammatory and anti-allergic properties. This study explores luteolin’s impact on chronic sinusitis. We isolated human nasal epithelial cells from sinusitis patients and used lipopolysaccharide-induced cells as a model. High-mobility group box 1 protein was notably elevated in these patients. Our findings suggest that luteolin can suppress the expression of inflammatory cytokines induced by lipopolysaccharide in these cells. Additionally, luteolin was able to inhibit the epithelial–mesenchymal transition in the treated cells. This inhibitory effect on high-mobility group box 1 expression led to reduced inflammation and transition processes. Overall, luteolin could potentially be an effective treatment for chronic sinusitis, minimizing inflammation and cellular transition in nasal epithelial cells.

Sphingosine Prevents Rhinoviral Infections.

Rhinoviral infections cause approximately 50% of upper respiratory tract infections and novel treatment options are urgently required. We tested the effects of 10 μM to 20 μM sphingosine on the infection of cultured and freshly isolated human cells with minor and major group rhinovirus in vitro. We also performed in vivo studies on mice that were treated with an intranasal application of 10 μL of either a 10 μM or a 100 μM sphingosine prior and after infection with rhinovirus strains 1 and 2 and determined the infection of nasal epithelial cells in the presence or absence of sphingosine. Finally, we determined and characterized a direct binding of sphingosine to rhinovirus. Our data show that treating freshly isolated human nasal epithelial cells with sphingosine prevents infections with rhinovirus strains 2 (minor group) and 14 (major group). Nasal infection of mice with rhinovirus 1b and 2 is prevented by the intranasal application of sphingosine before or as long as 8 h after infection with rhinovirus. Nasal application of the same doses of sphingosine exerts no adverse effects on epithelial cells as determined by hemalaun and TUNEL stainings. The solvent, octylglucopyranoside, was without any effect in vitro and in vivo. Mechanistically, we demonstrate that the positively charged lipid sphingosine binds to negatively charged molecules in the virus, which seems to prevent the infection of epithelial cells. These findings indicate that exogenous sphingosine prevents infections with rhinoviruses, a finding that could be therapeutically exploited. In addition, we demonstrated that sphingosine has no obvious adverse effects on the nasal mucosa. Sphingosine prevents rhinoviral infections by a biophysical mode of action, suggesting that sphingosine could serve to prevent many viral infections of airways and epithelial cells in general. Future studies need to determine the molecular mechanisms of how sphingosine prevents rhinoviral infections and whether sphingosine also prevents infections with other viruses inducing respiratory tract infections. Furthermore, our studies do not provide detailed pharmacokinetics that are definitely required before the further development of sphingosine.

Reduced Proliferative Capacity and Defense against Staphylococcus aureus in Human Nasal Mucosal Epithelium Lacking ZNF365

Introduction: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common chronic inflammatory disease of the nose characterized by barrier disruption and environmental susceptibility, and the deletion of ZNF365 may be a factor inducing these manifestations. However, there is no study on the mechanism of action between CRSwNP and ZNF365. Therefore, this study focuses on the effect of the zinc finger protein ZNF365 on the proliferation of nasal mucosal epithelial cells and their defense against Staphylococcus aureus (S. aureus). Methods: Immunohistochemistry and Western blot were applied to verify the changes of ZNF365 expression in nasal polyp tissues and control tissues, as well as in primary epithelial cells. ZNF365 was knocked down in human nasal mucosa epithelial cell line (HNEpc), and the proliferation, migration, and transdifferentiation of epithelium were observed by immunofluorescence, QPCR, CCK8, and cell scratch assay. The changes of mesenchymal markers and TLR4-MAPK-NF-κB pathway were also observed after the addition of S. aureus. Results: ZNF365 expression was reduced in NP tissues and primary nasal mucosal epithelial cells compared to controls. Knockdown of ZNF365 in HNEpc resulted in decreased proliferation and migration ability of epithelial cells and abnormal epithelial differentiation (decreased expression of tight junction proteins). S. aureus stimulation further inhibited epithelial cell proliferation and migration, while elevated markers of epithelial-mesenchymal transition and inflammatory responses occurred. Conclusion: ZNF365 is instrumental in maintaining the proliferative capacity of nasal mucosal epithelial cells and defending against the invasion of S. aureus. The findings suggest that ZNF365 may participate in the development of CRSwNP.

Redox Imbalance in Nasal Epithelial Cells of Primary Ciliary Dyskinesia Patients.

Background: Primary Ciliary Dyskinesia (PCD) represents a rare condition marked by an abnormal mobility pattern of cilia and flagella, resulting in impaired mucociliary clearance. This deficiency leads to recurrent infections and persistent inflammation of the airways. While previous studies have indicated heightened oxidative stress levels in the exhaled breath condensate of pediatric PCD patients, the assessment of oxidative stress within the affected respiratory tissue remains unexplored. Aims: To assess the oxidative status of human nasal epithelial cells (NECs) in PCD patients. Methods: Thirty-five PCD patients and thirty-five healthy control subjects were prospectively included in the study. Levels of reactive oxygen species (ROS), reactive nitrogen species (RNS), glutathione (GSH), intracellular Ca2+, plasma membrane potential, and oxidative damage in lipids and proteins were measured. In addition, apoptosis and mitochondrial function were analyzed by flow cytometry in NECs. Results: NECs from PCD patients showed reduced levels of apoptosis (p = 0.004), superoxide anion (O2-, p = 0.018), peroxynitrite (ONOO-, p = 0.007), nitric oxide (NO, p = 0.007), mitochondrial hydrogen peroxide (mtH2O2, p < 0.0001), and mitochondrial superoxide anion (mtO2-, p = 0.0004) and increased mitochondrial mass (p = 0.009) compared to those from healthy individuals. No significant differences were observed in oxidized proteins (p = 0.137) and the oxidized/reduced lipid ratio (p = 0.7973). The oxidative profile of NEC cells in PCD patients, according to their ciliary motility, recurrent otitis, recurrent pneumonia, atelectasis, bronchiectasis, and situs inversus, showed no statistically significant differences in the parameters studied. Conversely, patients with chronic rhinosinusitis exhibited lower levels of ONOO- than PCD patients without this condition, with no significant differences related to other symptoms. Conclusions: Our findings strongly suggest the presence of a redox imbalance, specifically leaning toward a reductive state, in PCD patients.

Comparison of permeable cell culture inserts for use in culture of a human invitro air-liquid interface model system.

In this study, we compared 12 mm cell culture inserts with permeable polyester membranes (0.4 μm pores) from two different manufacturers: CELLTREAT® and Corning®. Physical dimensions and masses of the inserts were found to be very similar between the two brands, with CELLTREAT® inserts having a slightly smaller diameter and growth area (11.91 mm; 1.11 cm2 ) compared to Corning® Transwells® (12 mm; 1.13 cm2 ). We compared cell differentiation outcomes of human nasal epithelial cells (HNECs) at air-liquid interface grown on inserts from the two different manufacturers, including trans-epithelial electrical resistance, ciliary beat frequency, ciliated area, and gene expression. HNECs from three male donors were used for all endpoints. No statistically significant differences were observed between paired cultures grown on different brands of insert. In conclusion, these inserts are comparable for use with airway epithelial cell model systems and likely do not impact cellular differentiation or cell culture quality.

LINC01094 promotes human nasal epithelial cell epithelial-to-mesenchymal transition and pyroptosis via upregulating HMGB1.

Excessive epithelial-to-mesenchymal transition (EMT) of nasal epithelial cells (NECs) play a prominent role in chronic rhinosinusitis with nasal polyps (CRSwNP) pathogenesis. Long intergenic non-coding RNA 01094 (LINC01094) was previously reported to be overexpressed in CRSwNP, while the regulatory mechanism by which LINC01094 regulates CRSwNP progression remains unclear. Our study aimed to investigate the role of LINC01094 in CRSwNP development. hNEC were isolated from tissues of controls and CRSwNP patients and stimulated with interleukin (IL)-13. 3-(4, 5-Dimethylthiazolyl2)-2, 5-diphenyltetrazolium bromide (MTT) assay was employed to analyze hNEC viability. Flow cytometry was employed to analyze pyroptosis. Immunofluorescence was employed to analyze Snail nuclear translocation. The interactions between LINC01094, fused in sarcoma (FUS) and high mobility group box-1 (HMGB1) were analyzed by RNA immunoprecipitation (RIP) and RNA pull-down assays. LINC01094 and EMT-related proteins were markedly upregulated in nasal polyp tissues of CRSwNP. LINC01094 knockdown inhibited IL-13-induced hNEC EMT and pyroptosis. LINC01094 promoted HMGB1 expression in CRSwNP by binding with FUS. HMGB1 promoted Snail nuclear import in GSK-B phosphorylation-dependent manner. LINC01094 facilitated hNEC EMT and pyroptosis in CRSwNP by activating the HMGB1/GSK-B Snail axis, which suggested that LINC01094 might serve as a biomarker and therapeutic target in CRSwNP.

Lactobacillus rhamnosus dampens cytokine and chemokine secretion from primary human nasal epithelial cells infected with rhinovirus.

To investigate the effect of Lactobacillus rhamnosus on viral replication and cellular response to human rhinovirus (HRV) infection, including the secretion of antiviral and inflammatory mediators from well-differentiated nasal epithelial cells (WD-NECs). The WD-NECs from healthy adult donors (N=6) were cultured in vitro, exposed to different strains of L. rhamnosus (D3189, D3160, or LB21), and infected with HRV (RV-A16) after 24 h. Survival and adherence capacity of L. rhamnosus in a NEC environment were confirmed using CFSE-labelled isolates, immunofluorescent staining, and confocal microscopy. Shed virus and viral replication were quantified using TCID50 assays and RT-qPCR, respectively. Cytotoxicity was measured by lactate dehydrogenase (LDH) activity. Pro-inflammatory mediators were measured by multiplex immunoassay, and interferon (IFN)-λ1/3 was measured using a standard ELISA kit. Lactobacillus rhamnosus was able to adhere to and colonize WD-NECs prior to the RV-A16 infection. Lactobacillus rhamnosus did not affect shed RV-A16, viral replication, RV-A16-induced IFN-λ1/3 production, or LDH release. Pre-exposure to L. rhamnosus, particularly D3189, reduced the secretion of RV-A16-induced pro-inflammatory mediators by WD-NECs. These findings demonstrate that L. rhamnosus differentially modulates RV-A16-induced innate inflammatory immune responses in primary NECs from healthy adults.

Specialized proresolving mediator resolvin E1 corrects the altered cystic fibrosis nasal epithelium cilia beating dynamics

In cystic fibrosis (CF), impaired mucociliary clearance leads to chronic infection and inflammation. However, cilia beating features in a CF altered environment, consisting of dehydrated airway surface liquid layer and abnormal mucus, have not been fully characterized. Furthermore, acute inflammation is normally followed by an active resolution phase requiring specialized proresolving lipid mediators (SPMs) and allowing return to homeostasis. However, altered SPMs biosynthesis has been reported in CF. Here, we explored cilia beating dynamics in CF airways primary cultures and its response to the SPMs, resolvin E1 (RvE1) and lipoxin B4 (LXB4). Human nasal epithelial cells (hNECs) from CF and non-CF donors were grown at air-liquid interface. The ciliary beat frequency, synchronization, orientation, and density were analyzed from high-speed video microscopy using a multiscale Differential Dynamic Microscopy algorithm and an in-house developed method. Mucins and ASL layer height were studied by qRT-PCR and confocal microscopy. Principal component analysis showed that CF and non-CF hNEC had distinct cilia beating phenotypes, which was mostly explained by differences in cilia beat organization rather than frequency. Exposure to RvE1 (10 nM) and to LXB4 (10 nM) restored a non-CF-like cilia beating phenotype. Furthermore, RvE1 increased the airway surface liquid (ASL) layer height and reduced the mucin MUC5AC thickness. The calcium-activated chloride channel, TMEM16A, was involved in the RvE1 effect on cilia beating, hydration, and mucus. Altogether, our results provide evidence for defective cilia beating in CF airway epithelium and a role of RvE1 and LXB4 to restore the main epithelial functions involved in the mucociliary clearance.

A tetravalent bispecific antibody outperforms the combination of its parental antibodies and neutralizes diverse SARS-CoV-2 variants

The devastating impact of COVID-19 on global health shows the need to increase our pandemic preparedness. Recombinant therapeutic antibodies were successfully used to treat and protect at-risk patients from COVID-19. However, the currently circulating Omicron subvariants of SARS-CoV-2 are largely resistant to therapeutic antibodies, and novel approaches to generate broadly neutralizing antibodies are urgently needed. Here, we describe a tetravalent bispecific antibody, A7A9 TVB, which actively neutralized many SARS-CoV-2 variants of concern, including early Omicron subvariants. Interestingly, A7A9 TVB neutralized more variants at lower concentration as compared to the combination of its parental monoclonal antibodies, A7K and A9L. A7A9 also reduced the viral load of authentic Omicron BA.1 virus in infected pseudostratified primary human nasal epithelial cells. Overall, A7A9 displayed the characteristics of a potent broadly neutralizing antibody, which may be suitable for prophylactic and therapeutic applications in the clinics, thus highlighting the usefulness of an effective antibody-designing approach.

Human apical-out nasal organoids reveal an essential role of matrix metalloproteinases in airway epithelial differentiation

Extracellular matrix (ECM) assembly/disassembly is a critical regulator for airway epithelial development and remodeling. Airway organoid is widely used in respiratory research, yet there is limited study to indicate the roles and mechanisms of ECM organization in epithelial growth and differentiation by using in vitro organoid system. Moreover, most of current Matrigel-based airway organoids are in basal-out orientation where accessing the apical surface is challenging. We present a human apical-out airway organoid using a biochemically defined hybrid hydrogel system. During human nasal epithelial progenitor cells (hNEPCs) differentiation, the gel gradually degrade, leading to the organoid apical surfaces facing outward. The expression and activity of ECM-degrading enzymes, matrix metalloproteinases (MMP7, MMP9, MMP10 and MMP13) increases during organoid differentiation, where inhibition of MMPs significantly suppresses the normal ciliation, resulting in increased goblet cell proportion. Moreover, a decrease of MMPs is found in goblet cell hyperplastic epithelium in inflammatory mucosa. This system reveals essential roles of epithelial-derived MMPs on epithelial cell fate determination, and provides an applicable platform enabling further study for ECM in regulating airway development in health and diseases.

Responses of primary human nasal epithelial cells to COVID-19 vaccine candidate.

Upper respiratory tract is the primary target of SARS-CoV-2. Therefore, nasal immune responses act as the first line of defense against SARS-CoV-2 infection. We aim to investigate the immune responses of human nasal epithelial cells (HNEpCs) upon stimulation with a COVID-19 vaccine candidate. This candidate named RBD-NPs is composed of SARS-CoV-2 receptor-binding domain (RBD) encapsulated within the N,N,N-trimethyl chitosan nanoparticles (TMC-NPs). HNEpCs were stimulated with RBD-NPs, empty NPs, or soluble RBD at various concentrations. After 24 and 48 h of treatment, cells viability and delivery of the immunogens were assessed using XTT assay and flow cytometry. Levels of cytokines and chemokines in the supernatant were quantified with Bio-plex Human Cytokine Assay. Communication between RBD-NPs-stimulated HNEpCs and monocyte-derived dendritic cells (MoDCs) was assessed through differentiation of MoDCs into mature phenotype. RBD-NPs as high as 100 μg exerted no toxicity to HNEpCs and could effectively be delivered to HNEpCs. Treatment of HNEpCs with RBD-NPs strongly activated production of several pro-inflammatory cytokines, chemokines, Th1-related cytokines and the monocytes/macrophages growth factors. Interestingly, soluble mediators secreted from RBD-NPs treated HNEpCs significantly upregulated the expression of maturation markers (CD80, CD83, CD86 and HLA-DR) on the MoDCs. This study demonstrated that our COVID-19 vaccine candidate drove HNEpCs into immunologically competent cells that not only exerted anti-viral innate immune responses but also potently induced MoDCs maturation.

TGF-β1 induces epithelial-to-mesenchymal transition in chronic rhinosinusitis with nasal polyps through microRNA-182.

Epithelial-to-mesenchymal transition (EMT) in nasal epithelial cells is involved in tissue remodeling of chronic rhinosinusitis with nasal polyps (CRSwNP). Our study investigated the molecular mechanisms that microRNA-182 (miR-182) regulated EMT in eosinophilic (Eos) and non-eosinophilic (non-Eos) CRSwNP. To investigate the mechanism by which miR-182 regulates EMT in human nasal epithelial cells (hNEPCs). The expression of EMT markers (E-cadherin, N-cadherin and vimentin), transforming growth factor (TGF)-β1, and miR-182 were determined by western blotting and reverse transcription-quantitative PCR (RT-qPCR). Fluorescence in situ hybridization (FISH) was used to detect the miR-182 localization. Additionally, EMT markers expression and cell morphology changes were checked upon treatment with TGF-β1, or TGF-β1 with miR-182 inhibitor, or miR-182 mimics, or miR-182 inhibitor alone in hNEPCs. In both Eos CRSwNP and non-Eos CRSwNP, the expression levels of E-cadherin were downregulated while the expression levels of N-cadherin, vimentin, TGF-β1 and miR-182 were significantly upregulated compared with control nasal tissues. Additionally, more significant changes in these EMT markers were observed in the Eos-CRSwNP when compared with the non-Eos CRSwNP. Invitro hNEPCs model, TGF-β1 upregulated miR-182 expression and promoted EMT in hNEPCs, indicated by changes in cell morphology and EMT markers expression. Furthermore, these upregulations were reversed by miR-182 inhibitor. This study showed that miR-182-induced EMT in response to TGF-β1 might promote nasal polypogenesis in both Eos CRSwNP and non-Eos CRSwNP, thus providing potential targets for the future development of novel therapeutic approaches for the management of CRSwNP.

EPS T14 from Bacillus licheniformis Prevents Infection of Human Nasal Epithelial Cells by Respiratory Viruses.

Respiratory viral infections are a leading cause of severe diseases and mortality; therefore, novel treatments effective for their prevention are highly requested. Here, we identified a broad-spectrum antiviral activity of a natural exopolysaccharide, EPS T14, purified from a marine thermotolerant strain of Bacillus licheniformis strain T14. The effects on human normal nasal epithelial cells (HNEpCs) following treatment with EPS T14 was evaluated at different time points and with increasing concentration of compound. To assess the antiviral properties, viability of HNEpCs treated with EPS T14 was analysed following infection with different respiratory viruses. Neither toxicity nor pro-inflammatory properties were observed in vitro on HNEpCs treated with EPS T14 up to high concentrations, thus ensuring its safety. Cell culture-based assays revealed that treatment of HNEpCs with EPS T14 (used at 400ug/mL) results in efficient prevention of cell infection by different respiratory viruses through physically hindering the entry of the viruses via cell surface receptors. Interestingly, in addition to this prophylactic antiviral activity, EPS T14 also shows a long-lasting efficacy by inhibiting viral spread in the cell culture. Finally, combination of EPS T14 with a hypertonic saline solution shows a synergistic antiviral activity. EPS T14 can exert both prophylactic and therapeutic antiviral activity by blocking viral attachment to cellular receptors and could therefore represent a promising antiviral agent for preventing infections by different respiratory viruses.

Downregulation of TET2 Contributes to Nasal Polypogenesis Through Hypoxia-Inducible Factor 1α-Mediated Epithelial-to-Mesenchymal Transition.

Hypoxia-inducible factor 1α (HIF1α) and Tet methylcytosine dioxygenase 2 (TET2) have been reported to mediate nasal polypogenesis through the epithelial-to-mesenchymal transition (EMT). Additionally, HIF1α can regulate the expression and function of TET2. However, the precise mechanism of how TET2 regulates the EMT through HIF1α mediation in nasal epithelial cells is still poorly understood. Nasal tissue samples were collected from patients with chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP), CRS without nasal polyps (CRSsNP), and controls. The expression of HIF1α and TET2 was detected using Western blotting and immunohistochemistry. EMT markers (E-cadherin and vimentin) were also evaluated by immunohistochemistry. Primary human nasal epithelial cells (hNECs) were stimulated with CoCl2 to mimic hypoxia. Vitamin C (VC), a TET2 non-specific activator, and small interfering RNA (siRNA) transfection of TET2 were used to further determine the role of TET2 in hypoxia-induced EMT. Finally, reactive oxygen species (ROS) and Nrf2 were measured to explore the downstream consequences of TET2 in hypoxic hNECs. TET2 levels were lower in the nasal epithelium of CRSwNP patients and were positively correlated with E-cadherin but negatively correlated with vimentin in CRS. However, HIF1α exhibited the opposite pattern and was negatively correlated with TET2 expression. CoCl2-simulated hypoxia led to EMT and increased HIF1α in hNECs in vitro, with simultaneous downregulation of TET2 expression. Addition of VC activated TET2 expression in hNECs, but inhibited EMT and HIF1α expression. Furthermore, siRNA knockdown of TET2 contributed to the EMT in CoCl2-simulated hNECs despite the addition of VC. Finally, TET2 regulated the EMT in hypoxic hNECs through Nrf2 expression and ROS generation. TET2 was negatively correlated with HIF1α and EMT in vivo. TET2 was downregulated by HIF1α, resulting in the EMT in CoCl2-hypoxic hNECs via regulation of oxidative stress in vitro. Hence, TET2 might provide a new therapeutic approach for CRSwNP.

ELV-N34 or RvD6-isomer Counteracts Damaging Astrocyte Phenotypes Protecting the Brain from Omicron BA.5 Sequelae

Neurodegenerative diseases induce astrocyte phenotypes that trigger inflammation and cell damage. This cell induction also takes place in post-acute neurological syndrome from SARS-CoV-2 infection. We found that the secretome from Omicron BA.5 infected human nasal epithelial or human lung cells induced the activation of human astrocytes to a reactive pro-inflammatory phenotype as defined by nuclear translocation of NF-kB/p65. Remarkably, the secretome from these cells incubated with Elovanoid (ELV)-N34 or Resolvin D6 (RvD6)-isomer (500nM) did not trigger the formation of reactive astrocytes. One of the factors involved is CXCL1, secreted by Omicron BA.5-infected nasal epithelial cells. So, when CXCL1 was administered intranasally to mice along with Interferon type I, the infiltration of fluorescein indicated a permeabilization of the neurovascular unit. Astrocytes are close to this barrier and contribute to restricting the access of damaging molecules to the brain parenchyma. Together, these results point to a specific way of entry of chemokines and cytokines as part of the secretome from infected cells that may play a role in long COVID brain sequelae.

The IL-31/CysLT2R axis is associated with itching in patients with allergic rhinitis.

Itching is a troublesome symptom that disturbs patients with allergic rhinitis (AR). The molecular mechanisms underlying itching in AR need to be further illuminated. The aim of this study was to investigate the role of epithelial cell-derived interleukin-31 (IL-31) in nasal itching in AR. A total of 33 patients and 20 healthy control subjects were enrolled in this prospective study. The disease severity of patients with AR was assessed by the total visual analog scale score. The levels of IL-31, cysteinyl leukotriene receptor 1 (CysLT1R), and CysLT2R in the nasal brush specimens from the enrolled subjects were measured by quantitative real-time polymerase chain reaction (RT-PCR) and immunohistochemical staining. The expression of CysLT2R in a human nasal epithelial cell line (HNEpC) was assessed by immunofluorescence staining. Compared with the control subjects, the protein and mRNA levels of IL-31 and CysLT2R were significantly increased in patients with AR. Higher levels of IL-31 and CysLT2R in nasal epithelial cells were associated with itching but not nasal congestion, rhinorrhea, or sneezing in AR. A significant relationship was found between IL-31 and CysLT2R in nasal epithelial cells, with a correlation coefficient of 0.93. Furthermore, RT-PCR and immunofluorescence staining revealed that IL-31 directly induced CysLT2R expression in HNEpCs. Nasal steroid treatment inhibited IL-31 and CysLT2R expression in 13 patients with AR in vivo. Nasal epithelial cell-derived IL-31 might be associated with itching symptoms via CysLT2R in AR.

LncRNA FGD5-AS1 Alleviates Inflammation in Allergic Rhinitis through the miR-223-3p/COX11 Axis

Introduction: Long noncoding RNAs (lncRNAs) have been implicated in the pathogenesis of allergic rhinitis (AR). The current investigation is focused on elucidating the functional impact of a specific lncRNA, FGD5 antisense RNA 1 (FGD5-AS1), on the development and progression of AR through its interaction with miR-223-3p. Methods: An experimental framework for AR was constructed in both cellular and animal models. Quantitative assessment of FGD5-AS1, miR-223-3p, and COX11 mRNA expression was conducted using real-time quantitative reverse transcription PCR. The expression of inflammatory factors, immunoglobulin E, LTC4, and ECP, was examined using ELISA. Apoptosis in human nasal epithelial cells was assessed by the flow cytometry method. The protein expression of COX11 was examined using Western blotting. Nasal mucosal function was further evaluated by hematoxylin and eosin staining. Furthermore, bioinformatics evaluations, dual-luciferase reporter assays, and a series of experimental procedures unveiled a putative competitive endogenous RNA regulatory mechanism. Results: We found the expression of lncRNA FGD5-AS1 was decreased in AR. In vitro lncRNA FGD5-AS1 attenuated the production of inflammatory cytokines in nasal epithelial cells. Furthermore, elevated FGD5-AS1 expression significantly alleviated AR symptoms by reducing nasal epithelial apoptosis and inflammation. MiR-223-3p was identified as a direct target of FGD5-AS1. Moreover, miRNA-223-3p directly downregulated the expression of COX11 mRNA. Subsequent experiments confirmed that FGD5-AS1 regulated AR through the miR-223-3p/COX11 axis, thereby inhibiting inflammation. Conclusion: The FGD5-AS1/miR-223-3p/COX11 axis plays a pivotal role in the pathogenesis of AR, suggesting that FGD5-AS1 could serve as a potential diagnostic biomarker and therapeutic target for AR.

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 NEDD4Linhibitedthe β-catenin/HIF-1α positive feedback loop either directly(degrading β-catenin and HIF-1α) or indirectly (mediatingDDR1 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.