Overexpression of hypoxia-inducible factor 1α is associated with neutrophilic inflammation in chronic rhinosinusitis with nasal polyps

Enhanced oxidative stress is associated with tissue neutrophilia and poor steroid response in chronic rhinosinusitis with nasal polyps

Objective

To analyze the oxidative stress status and its association with tissue neutrophilia and oral steroid response in chronic rhinosinusitis with nasal polyps (CRSwNP) patients.

Methods

The levels of total oxidant status (TOS) were detected in the sinonasal tissues by using specific assay kits. Tissue neutrophil was examined by immunohistochemical staining, and oxidant status index (OSI) was evaluated in polyps tissues, and the messenger RNA (mRNA) levels of superoxide dismutase 2 (SOD2), aldehyde dehydrogenase 1 (ALDH1A1), and microsomal glutathione S-transferase 1 (MGST1) were examined using quantitative real-time polymerase chain reaction in the sinonasal tissues. The receiver operating characteristics (ROCs) curve of ALDH1A1, MGST1, and SOD2 mRNA levels were evaluated to determine the steroid response of CRSwNP patients.

Results

The levels of TOS and OSI were significantly higher in CRSwNP and CRSsNP than in normal controls, and OSI in polyps tissues was positively associated with tissue neutrophilia and poor steroid response. The ALDH1A1, MGST1, and SOD2 mRNA levels showed comparable accuracy as predictors of poor steroid response indicated by the area under the curve.

Conclusion

These findings provided evidence that the increased level of oxidative stress contributes to enhanced tissue neutrophilia and poor steroid response in CRSwNP patients.

Increased IL-1α expression in chronic rhinosinusitis with nasal polyps

PURPOSE

To examine whether and how interleukin (IL)-1α is involved in chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODS

Nasal polyp (NP) and control tissues were collected from CRSwNP patients and control subjects. The expression of IL-1α and other proinflammatory cytokines (IL-1β, IL-8 and IL-13, etc.), as well as neutrophil and eosinophil accumulation, were examined in sinonasal tissues using immunohistochemical (IHC), immunofluorescent (IF) staining, qPCR, and Luminex, respectively. Moreover, the regulation of IL-1α expression and its effects on other proinflammatory cytokines were evaluated in cultured nasal epithelial cells (NECs).

RESULTS

The mRNA and protein levels of IL-1α were significantly higher in NP tissues compared to that in control tissues. IL-1α in polyp tissues was mainly located in epithelial cells and neutrophils. Polyps IL-1α level was significantly associated with IL-8, IL-1β, IL-6, IL-4 and IL-13 production, as well as tissue neutrophil infiltration. Moreover, poly (I:C), lipopolysaccharides, Flagellin, R848 and cytokines (IL-4, IL-5, and IL-13) significantly increased the expression of IL-1α in cultured NECs in vitro, and recombinant IL-1α significantly promoted production of IL-8 and CXCL1 in cultured NECs.

CONCLUSIONS

These findings provided the evidence that IL-1α were significantly increased in NP tissues, which may contribute to tissue neutrophilia in CRSwNP patients in China.

Neutrophilic inflammation in chronic rhinosinusitis

PURPOSE OF REVIEW

Over the last years, extensive research has been done on neutrophils and their contribution in chronic rhinosinusitis (CRS), and made it clear that they are more than just a bystander in this disease. In this article, we will review all recent publications on this topic and look to what the future hold regarding therapeutics targeting the neutrophilic inflammation in CRS.

RECENT FINDINGS

Evidence is growing that the presence of neutrophils are associated with a worse disease outcome in certain CRS patient groups. They are highly activated in type 2 inflammations and exhibit damaging properties through their proteases, contributing to the chronicity of the disease. Several recent studies identified useful biomarkers and targets for future therapeutics.

SUMMARY

The findings we review in this manuscript are of utmost importance in unraveling the complexity of CRS and provide us with the necessary knowledge for future clinical practices.

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.

The role of hypoxia in the pathophysiology of chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease of the nasal cavity characterized by excessive nasal mucus secretion and nasal congestion. The development of CRS is related to pathological mechanisms induced by hypoxia. Under hypoxic conditions, the stable expression of both Hypoxia inducible factor-1 (HIF-1) α and HIF-2α are involved in the immune response and inflammatory pathways of CRS. The imbalance in the composition of nasal microbiota may affect the hypoxic state of CRS and perpetuate existing inflammation. Hypoxia affects the differentiation of nasal epithelial cells such as ciliated cells and goblet cells, induces fibroblast proliferation, and leads to epithelial-mesenchymal transition (EMT) and tissue remodeling. Hypoxia also affects the proliferation and differentiation of macrophages, eosinophils, basophils, and mast cells in sinonasal mucosa, and thus influences the inflammatory state of CRS by regulating T cells and B cells. Given the multifactorial nature in which HIF is linked to CRS, this study aims to elucidate the effect of hypoxia on the pathogenic mechanisms of CRS.

Immunological Aspects of Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is related to persistent inflammation with a dysfunctional relationship between environmental agents and the host immune system. Disturbances in the functioning of the sinus mucosa lead to common clinical symptoms. The major processes involved in the pathogenesis of CRS include airway epithelial dysfunctions that are influenced by external and host-derived factors which activate multiple immunological mechanisms. The molecular bases for CRS remain unclear, although some factors commonly correspond to the disease: bacterial, fungal and viral infections, comorbidity diseases, genetic dysfunctions, and immunodeficiency. Additionally, air pollution leads increased severity of symptoms. CRS is a heterogeneous group of sinus diseases with different clinical courses and response to treatment. Immunological pathways vary depending on the endotype or genotype of the patient. The recent knowledge expansion into mechanisms underlying the pathogenesis of CRS is leading to a steadily increasing significance of precision medicine in the treatment of CRS. The purpose of this review is to summarize the current state of knowledge regarding the immunological aspects of CRS, which are essential for ensuring more effective treatment strategies.

Role of curcumin in selected head and neck lesions. Limitations on the use of the Hep-2 cell line: A critical review

Neoplastic diseases of the upper respiratory airways, as well as head and neck cancers, are a frequent cause of death and significantly affect the quality of life of both patients and survivors. As the frequency increases, new and improved treatment techniques are sought. Promising properties in this respect are expressed by a natural compound - curcumin. Along with its derivatives, it was found useful in the treatment of a series of cancers. Curcumin was found to be effective in clinical trials and in vitro, in vivo anticancer experiments. Nanoformulations (e.g., poly(lactide-co-glycolic acid)-based nanoparticles, nanoemulsions), and modifications of curcumin, as well as its combinations with other substances (e.g., catechins, cisplatin) or treatments (e.g., radiotherapy or local use in inhalation), were found to enhance the antitumor effect. This review aims to summarize the recent findings for the treatment of head and neck diseases, especially squamous cell carcinomas (HNSCCs), including drawing attention to the constant use of the misidentified Hep-2 cell line and proposing databases purposed at eliminating this problem. Moreover, this manuscript focuses on pointing out the molecular mechanisms of therapy that have been reached and emphasizing the shortcomings that still need to be addressed.

XBP1 Regulates the Transcription of HIF-1a in BALB/c Mice with Chronic Rhinosinusitis without Polyps

X-box binding protein 1 (XBP1) is a transcription factor that recognizes the CRE-like element in enhancers of human T-cell leukemia virus and MHC class II gene and induces their transcription. This study was performed to characterize the function of XBP1, which was identified to be a differentially expressed gene via GEO database, in chronic rhinosinusitis (CRS) without nasal polyps (CRSsNP). XBP1 expression was significantly elevated in both CRSsNP patients and mice who were accompanied with mucosal thickening, goblet cell hyperplasia and chemosis, glandular hyperplasia, and dense infiltration of inflammatory cells. Silencing of XBP1 suppressed the development of CRSsNP in mice. Mechanistically, knockdown of XBP1 downregulated the expression of hypoxia-inducible factor 1-alpha (HIF-1a), and overexpression of XBP1 led to the opposite result. Silencing of HIF-1a inhibited β-catenin expression and impaired the Wnt/β-catenin pathway. Further overexpression of HIF-1a in XBP1-silenced CRSsNP mice exacerbated pathological changes in mouse nasal mucosal tissues, promoted inflammation, and activated the Wnt/β-catenin pathway. Taken together, overexpression of XBP1 may be associated with increased expression of HIF-1a and possibly contribute to the Wnt/β-catenin pathway activation and the development of CRSsNP.

Hypoxia-inducible transcription factor-1α inhibition by topotecan protects against lipopolysaccharide-induced inflammation and apoptosis of cardiomyocytes

Background

Myocarditis, an inflammatory disease of the myocardium, is a serious hazard to human life due to the expansion of inflammatory lesions in the myocardium. The aim of this study was to investigate the role of hypoxia-inducible transcription factor (HIF)-1α and its inhibitor topotecan in the pathogenesis of myocarditis.

Methods

H9c2 cardiomyoblasts was stimulated with lipopolysaccharide (LPS) to simulate myocarditis model in vitro. The levels of myocardial damage markers were determined using commercially available kits. Western blotting was used to evaluate HIF-1α expression after LPS challenge. Then, after HIF-1α silencing, the contents of inflammatory factors were determined with enzyme-linked immunosorbent assay (ELISA). Cell viability was tested by means of a cell counting kit-8 (CCK-8) assay. Cell apoptosis was assessed by flow cytometry, and the expression of apoptotic proteins was examined using western blot analysis. Subsequently, HIF-1α was overexpressed and topotecan was employed to treat H9c2 cells under LPS exposure condition. The biological functions were detected again.

Results

LPS significantly elevated the levels of lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB) and cardiac troponin-I (cTn-I) in supernatant of H9c2 cell lysates. Additionally, LPS led to the notably upregulated expression of HIF-1α. HIF-1α-knockdown markedly decreased the concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-8 compared with the LPS-induced group. Moreover, the cell viability was conspicuously enhanced and cell apoptotic ratio was remarkably reduced, accompanied by downregulated expression of Bax, Bim, caspase 3 and caspase 9 after HIF-1α silencing. Consistently, HIF-1α gain-of-function significantly promoted the production of inflammatory cytokines and cell apoptosis, which was partially counteracted by topotecan administration.

Conclusion

To conclude, these findings demonstrated that HIF-1α inhibition by topotecan ameliorates LPS-induced myocarditis in vitro, providing a new approach in the treatment of myocarditis.

The Development of Glaucoma after Surgery-Indicated Chronic Rhinosinusitis: A Population-Based Cohort Study

This study investigates the development of glaucoma in subjects with surgery-indicated chronic rhinosinusitis (CRS) by the use of the National Health Insurance Research Database in Taiwan. Individuals that received the functional endoscopic sinus surgery (FESS) with a diagnostic code of CRS were regarded as surgery-indicated CRS and enrolled in the study group. Four non-CRS patients were age- and gender-matched to each patient in the study group. The exclusion criteria included legal blindness, ocular tumor, history of eyeball removal, and previous glaucoma. The outcome was regarded as the development of glaucoma, and conditional logistic regression was used for the statistical analysis, which involved multiple potential risk factors in the multivariate model. A total of 6506 patients with surgery-indicated CRS that received FESS and another 26,024 non-CRS individuals were enrolled after exclusion. The age and gender distributions were identical between the two groups due to matching. There were 108 and 294 glaucoma events in the study group and control group, respectively, during the follow-up period, and the study group had a significantly higher adjusted hazard ratio (1.291, 95% confidential interval: 1.031–1.615). The cumulative probability analysis also revealed a correlation between the occurrence of glaucoma and the CRS disease interval. In the subgroup analysis, the chance of developing open-angle glaucoma and normal-tension glaucoma was significantly higher in the study group than in the control group. In conclusion, the existence of surgery-indicated CRS is a significant risk factor for the development of glaucoma, which correlated with the disease interval.