Rhinosinusal Inflammation and High Mobility Group Box 1 Protein: A New Target for Therapy

Sphk1 regulates HMGB1 via HDAC4 and mediates epithelial pyroptosis in allergic rhinitis

Background

Allergic rhinitis (AR) is a global health issue affecting millions of individuals worldwide. Pyroptosis has emerged as a major player in the development of AR, and targeting its inhibition with specific drugs holds promise for AR treatment. However, a comprehensive understanding of the precise mechanisms underlying pyroptosis in AR remains to be explored, warranting further investigation.

Objective

This study aims to elucidate the roles of HMGB1, Sphk1, and HDAC4 in regulating human nasal epithelial cell (hNEC) pyroptosis and AR.

Methods

An in vitro AR cell culture model and an in vivo AR mouse model were established. Western blot, ELISA, histological staining, and flow cytometry were utilized to confirm the gene and protein expression. The interactions among Sphk1, HDAC4, and HMGB1 were validated through ChIP, Co-IP, and Dual-luciferase assay.

Results and conclusion

We identified that the expression levels of Sphk1, HMGB1, and inflammasome components, including IL-18, and IL-1β were elevated in AR patients and mouse models. Knockdown of Sphk1 inhibited hNEC pyroptosis induced by dust mite allergen. Overexpression of HDAC4 suppressed HMGB1-mediated pyroptosis in hNECs. In addition, HDAC4 was found to mediate the transcriptional regulation of HMGB1 via MEF2C, a transcription factor. Additionally, Sphk1 was shown to interact with CaMKII-δ, promoting the phosphorylation of HDAC4 and inhibiting its cytoplasmic translocation. Knockdown of HDAC4 reversed the effect of Sphk1 knockdown on pyroptosis. These discoveries offer a glimpse into the molecular mechanisms underlying AR and suggest potential therapeutic targets for the treatment of this condition.

Glycyrrhizin and Mannitol Nasal Therapy: Cytological and Clinical Outcomes in Chronic Rhinitis

Introduction  Chronic rhinitis (CR) represents a widespread inflammation with a high incidence in the general population. Although it is generally considered a benign condition, CR has a relevant impact on quality of life and requires a specific treatment approach. Objective  The aim of the present study was to investigate the efficacy of glycyrrhizin and mannitol intranasal treatment on chronic rhinitis using cytological analysis and subjective evaluation of symptoms. Methods  A total of 55 patients suffering from chronic rhinitis were enrolled in the present study, 34 with allergic rhinitis (AR) and 21 with nonallergic rhinitis (NAR). The severity of four different nasal symptoms was determined by using a visual analogue scale (VAS). Specimens obtained by nasal scraping were collected for cytological analysis. Data were acquired before and after a 30-day treatment with glycyrrhizin and mannitol nasal spray. Statistical analyses were performed. Results  The VAS scores for all four nasal symptoms considered in the present study, as well as for neutrophil cells, reduced significantly after therapy in both allergic and nonallergic patients. The number of eosinophils was not significantly lower in nonallergic patients. Conclusion  A 30-day topical treatment with glycyrrhizin and mannitol may improve nasal symptoms and reduce inflammatory cells in the nasal mucosa in patients with chronic rhinitis without significant contraindications. Further studies could support our results and would better clarify all the aspects of this treatment.

Inflammation balance in skeletal muscle damage and repair

Responding to tissue injury, skeletal muscles undergo the tissue destruction and reconstruction accompanied with inflammation. The immune system recognizes the molecules released from or exposed on the damaged tissue. In the local minor tissue damage, tissue-resident macrophages sequester pro-inflammatory debris to prevent initiation of inflammation. In most cases of the skeletal muscle injury, however, a cascade of inflammation will be initiated through activation of local macrophages and mast cells and recruitment of immune cells from blood circulation to the injured site by recongnization of damage-associated molecular patterns (DAMPs) and activated complement system. During the inflammation, macrophages and neutrophils scavenge the tissue debris to release inflammatory cytokines and the latter stimulates myoblast fusion and vascularization to promote injured muscle repair. On the other hand, an abundance of released inflammatory cytokines and chemokines causes the profound hyper-inflammation and mobilization of immune cells to trigger a vicious cycle and lead to the cytokine storm. The cytokine storm results in the elevation of cytolytic and cytotoxic molecules and reactive oxygen species (ROS) in the damaged muscle to aggravates the tissue injury, including the healthy bystander tissue. Severe inflammation in the skeletal muscle can lead to rhabdomyolysis and cause sepsis-like systemic inflammation response syndrome (SIRS) and remote organ damage. Therefore, understanding more details on the involvement of inflammatory factors and immune cells in the skeletal muscle damage and repair can provide the new precise therapeutic strategies, including attenuation of the muscle damage and promotion of the muscle repair.

miR-1287-5p upregulation inhibits the EMT and pro-inflammatory cytokines in LPS-induced human nasal epithelial cells (HNECs)

BACKGROUND

Chronic rhinosinusitis is an intractable symptom that influences daily lives of patients. miR-1287-5p was discovered to play a suppressive role in cervical cancer and HBV-related infection.

PURPOSE

This study investigated the potential role of miR-1287-5p in the in-vitro model of chronic rhinosinusitis.

METHODS

GSE169376 dataset was analyzed and differential miRNAs in nasal mucosa tissues in the chronic rhinosinusitis group were screened out. LPS was used to treat HNECs for 12h, 24h and 48h. Cells underwent LPS treatment after SNAI1 downregulation, miR-1287-5p upregulation or pretreatment of the HMGB1 inhibitor, Glycyrrhizin. RT-PCR was used to measure the RNA expression of miR-1287-5p, SNAI1 and HMGB1. ELISA was used for the detection of IL-6, IL-8, TNF-α changes. Targetscan and starBase were used to predict the targets (SNAI1 and HMGB1) of miR-1287-5p. Dual-luciferase reporter assays were applied to validate this. Western blot was used to analyze the protein changes of Snai1, Vimentin, E-cadherin and HMGB1.

RESULTS

miR-1287-5p was downregulated in the chronic rhinosinusitis group and decreased after LPS treatment in HNECs. The upregulation of miR-1287-5p inhibited IL-6, IL-8, TNF-α and EMT. miR-1287-5p targeted and inhibited SNAI1 and HMGB1. SNAI1 downregulation led to inhibition in EMT while loss of HMGB1 contributed to the decrease in pro-inflammatory cytokines. Knockdown of SNAI1 decreased HMGB1, resulting in the reduction of pro-inflammatory cytokines while HMGB1 inhibitor reduced SNAI1 and thus suppressed the EMT process.

CONCLUSION

miR-1287-5p downregulation was associated with chronic rhinosinusitis and its upregulation inhibited the EMT and inflammation in LPS-induced HNECs through Snai1/HMGB1 pathway.

Epigallocatechin Gallate (EGCG) Improves Anti-Angiogenic State, Cell Viability, and Hypoxia-Induced Endothelial Dysfunction by Downregulating High Mobility Group Box 1 (HMGB1) in Preeclampsia

Background

Preeclampsia (PE) is a serious complication of pregnancy with no effective therapy. This study assessed whether epigallocatechin gallate (EGCG) could reduce the production of anti-angiogenic factors, improve cell viability, and suppress endothelial dysfunction in vitro via regulating high mobility group box 1 (HMGB1) in preeclampsia.

Material/Methods

Human umbilical vein endothelial cells (HUVECs) grown in conditioned medium from hypoxic JEG-3 cells were used to investigate the effects of EGCG on anti-angiogenic state, cell viability, and markers of endothelial dysfunction. To confirm that EGCG exerted its effects via HMGB1, we also examined the impact of EGCG on anti-angiogenic state, cell viability, and endothelial dysfunction following HMGB1 treatment in vitro.

Results

EGCG inhibited HMGB1 expression in hypoxic trophoblast cells in a dose-dependent manner. In addition, EGCG relieved anti-angiogenic state and endothelial dysfunction in hypoxic trophoblast cells by downregulating HMGB1. Moreover, EGCG dose-dependently promoted cell proliferation by downregulating HMGB1.

Conclusions

Taken together, our data show the protective role of EGCG in preeclampsia and revealed EGCG-mediated effects on the production of anti-angiogenic factors, cell viability, and endothelial dysfunction through downregulating HMGB1. These observations suggest that EGCG is a novel therapeutic candidate for preeclampsia.

Expression Pattern of HMGB1 Differs Between Eosinophilic Chronic Rhinosinusitis With Nasal Polyp and Non-Eosinophilic Chronic Rhinosinusitis With Nasal Polyp: A Preliminary Study

BACKGROUND

Eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) is histologically distinct from non-eosinophilic CRSwNP (NECRSwNP) and exhibits a high frequency of recurrence. The differences between the pathogenesis of ECRSwNP and NECRSwNP are not well-characterized. HMGB1 has been implicated in the pathogenesis of CRSwNPs; however, its precise contributions to ECRSwNP and NECRSwNP have not been established.

OBJECTIVE

We evaluated the role of HMGB1 in the pathogenesis of ECRSwNP.

METHODS

A total of 26 nasal polyps (NPs) from patients with ECRSwNP and NECRSwNP who underwent endoscopic sinus surgery were obtained. Western blotting and immunohistochemistry were performed to compare the HMGB1 levels between the NPs from ECRS and NECRS. A multiplex cytokine assay was performed to evaluate the levels of other cytokines and chemokines in exudates in the NPs. Nasal lavage fluids were used to evaluate extracellular HMGB1 levels using enzyme-linked immunosorbent assay.

RESULTS

HMGB1 expression in the NPs was higher in ECRSwNP than in NECRSwNP. The level of HMGB1 in the exudate within the NPs was significantly higher in ECRSwNP than in NECRSwNP. Furthermore, HMGB1 levels in nasal lavage fluids from ECRSwNP were higher than those from NECRSwNP. We found that HMGB1 levels in the exudate in NPs and in nasal lavage fluids effectively differentiate ECRSwNP from NECRSwNP.

CONCLUSION

Our results suggest that a high level of HMGB1 in NPs is an important factor for differentiating ECRSwNP from NECRSwNP. HMGB1 may play a role in the development of ECRSwNP and should be further evaluated.

HMGB1 mediates lipopolysaccharide-induced inflammation via interacting with GPX4 in colon cancer cells

Background

Inflammation is one of a main reason for colon cancer progression and poor prognosis. The high-mobility group box-1 (HMGB1) and glutathione peroxidase 4 (GPX4) are responsible for inflammation, but the relationship between HMGB1 and GPX4 remains unknown about inflammation in colon cancer.

Methods

RT-qPCR was carried out to investigate the expression of IL1β, IL6 and TNFα in colon cancer cells stimulated with LPS or siHMGB1. To observe the relationship between HMGB1, GPX4 and inflammation or ROS, Western blot assays were adopted. Pull-down, CoIP and immunohistochemistry assays were performed to further investigate the molecular mechanisms of HMGB1 and GPX4 in colon cancer.

Results

We report that HMGB1 mediates lipopolysaccharide (LPS)-induced inflammation in colon cancer cells. Mechanistically, acetylated HMGB1 interacts with GPX4, negatively regulating GPX4 activity. Furthermore, by utilizing siHMGB1 and its inhibitor, our discoveries demonstrate that HMGB1 knockdown can inhibit inflammation and reactive oxygen species (ROS) accumulation via NF-kB.

Conclusion

Collectively, our findings first demonstrate that acetylated HMGB1 can interact with GPX4, leading to inflammation, and providing therapeutic strategies targeting HMGB1 and GPX4 for colon cancer.

Correlation Between HMGB1 and TLR4 Expression in Sinonasal Mucosa in Patients With Chronic Rhinosinusitis

OBJECTIVES

Chronic rhinosinusitis (CRS) is one of the most common inflammations in the upper airway. Despite the wide prevalence of CRS, the pathogenesis of this disease is poorly understood. Several components of the innate immune system may play a significant role in CRS, including Toll-like receptor 4 (TLR4), TLR9, and high-mobility group box 1 protein (HMGB1). This study was conducted to determine the expression of TLR4, TLR9, HMGB1, and pNFκ-B p65 in paraffin-embedded blocks of patients with CRS with nasal polyps compared with those of the control group.

METHODS

Twenty-six formalin-fixed, paraffin-embedded samples from patients with confirmed CRS and 26 patients undergoing septoplasty due to anatomic variations and no other inflammatory nasal diseases as the control group were assessed. Expression patterns of HMGB1, TLR9, TLR4, and pNFκ-B p65 genes were examined using real-time quantitative reverse transcription polymerase chain reaction (Real-Time qRT-PCR). Statistical analyses were performed with SPSS and analyzed using unpaired 2-tailed t tests or 1-way analysis of variance.

RESULTS

Real-time PCR showed that the expression level of HMGB1 messenger RNA was significantly increased in the tissues of patients with CRS compared with controls (P < .05). The other 3 genes were also upregulated in the patients, but were not significant compared with control. Analysis of the Pearson correlation coefficient (r) revealed a significant positive correlation between HMGB1 and TLR4 (r = 0.79, P < .05) in patients and negative correlation between TLR4 and NfκB in the control group (r = 0.94; P < .05).

CONCLUSIONS

Both HMGB1 and TLR4 are increased in the paranasal sinus mucosa of patients with CRS. These results suggest a possible contribution of HMGB1 and its internal receptor (TLR4) in the pathophysiology of CRS.

Agonist of PPAR-γ Reduced Epithelial-Mesenchymal Transition in Eosinophilic Chronic Rhinosinusitis with Nasal Polyps via Inhibition of High Mobility Group Box1

Epithelial-mesenchymal transition (EMT) has been reported to occur in eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP). Among the cytokines that cause EMT, high mobility group box 1 (HMGB1) has been shown to give rise to EMT in airway epithelial cells. However, the mechanism of HMGB1-induced EMT in ECRSwNP is unknown. We explored the mechanism and possible inhibitor. Immunohistochemistry (IHC), immunofluorescence (IF), and western blot assay were used to detect the expression and location of HMGB1, peroxisome proliferator-activated receptor-γ (PPAR-γ), and EMT markers in eighteen ECRSwNP and twelve normal nasal mucosa tissues. Epithelial cells isolated from ECRSwNP were cultured with various doses of recombinant human HMGB1 (rhHMGB1) to study the expression of PPAR-γ, and EMT markers. Additionally, the ligand of PPAR-γ was incubated with epithelial cells to interfere with the effects of lipopolysaccharide (LPS) or rhHMGB1 to explore the effect on expression of HMGB1 and EMT markers. These results suggest that HMGB1 was highly expressed in ECRSwNP compared with its expression in control tissues, and EMT was also found highly in ECRSwNP compared with control tissues. Moreover, the cytoplasmic accumulation of HMGB1 in ECRSwNP was obvious compared with normal tissues. We also found dose-dependent induction by rhHMGB1 of up-regulation of N-cadherin and vimentin and down-regulation of ZO-1 and E-cadherin in epithelial cells isolated from ECRSwNP. The agonist of PPAR-γ not only reduced release of HMGB1 induced by LPS, but also reversed the EMT. The protective role of PPAR-γ also appeared in cells that had been incubated with rhHMGB1. In the current study, we discovered that the agonist of PPAR-γ has a potential role in inhibited HMGB1-induced EMT in ECRSwNP. The agonist of PPAR-γ may contribute to inhabit epithelial cells to become mesenchymal-like cells which play an important role in the pathogenesis of ECRSwNP.

HMBG1 as a Driver of Inflammatory and Immune Processes in the Pathogenesis of Ocular Diseases

High-mobility group box 1 (HMGB1) is a nuclear protein that can also act as an extracellular trigger of inflammation, proliferation, and migration in eye diseases. It induces signaling pathways by binding to the receptor for advanced glycation end products (RAGE) and Toll-like receptors (TLRs) 2, 4, and 9. This proinflammatory activity is considered to be important in the pathogenesis of a wide range of ocular diseases resulting from hemodynamic changes, presence of neovascular endothelial cells, secretion of intraocular immune factors or inflammation, and apoptosis of retinal cell layers. Further work is needed to elucidate in detail how HMGB1 contributes to ocular disease and how its damaging activity can be modulated. In this review, we summarize current knowledge on HMGB1 as a ligand that can evoke inflammation and immune responses in ocular diseases.

Nasal Muco-ciliary transport time alteration: efficacy of 18 B Glycyrrhetinic acid

BACKGROUND

Mucociliary clearance is the main self-clearing system of the nasal cavity and paranasal sinuses.This is a very important means of non specific defence against continuous organic and inorganic contamination conveyed by air. It works by trapping particles and microorganisms in the mucus and then by transporting the mucous film to the pharynx where it is eliminated with a cough or swallowed. Its congenital or acquired abnormalities are involved in the occurrence of widespread infectious and often severe nose and paranasal sinuses diseases; generally concerning the rhinopharyngealtubal district.Restoring mucociliary clearance of the nasal epithelium when altered thus represents a key therapeutic tool against rhinosinus chronic diseases.This study evaluates the clinical efficacy of the inhalation of a natural compound (Narivent® nasal spray) in chronic vasomotor rhinitis.

METHODS

The study involved 79 patients suffering from chronic vasomotor rhinitis presenting an increased mucociliary clearance time. Patients were randomized into 2 groups: a first group of 49 subjects and a second group of 30 subjects.The first group was treated with a nasal spray (Narivent® nasal spray) (2 sprays per nostril twice a day) for 30 days.The second group was treated with a nasal spray containing isotonic solution in the same way and for the same period of the first group.Nasal Mucociliary transport time was measured in the patients of both groups before treatment, after 15 days of treatment, and at the end of the 30 days treatment.

RESULTS

The study shows how one of the treatments carried out determines a major objective reduction of the mucociliary clearance time in the patients under examination, using the method which involves the use of an insoluble coloured tracer (vegetable carbon), bringing the values back within normal range. At the end of the study we objectivated an increase in the rate of mucociliary transport in 97.9% percentage of patients we enrolled.

CONCLUSIONS

This study shows the effectiveness of treatment with natural extracts with nasal mucosa restoring function in the treatment of chronic vasomotor rhinitis, a nasal inflammatory disease characterized by morphological and functional alteration of the normal nasal mucosa.