Deficiency of INPP4A promotes M2 macrophage polarization in eosinophilic chronic rhinosinusitis with nasal polyps.

OBJECTIVE: The treatment of eosinophilic chronic rhinosinusitis with nasal polyps (E-CRSwNP) remains a challenge due to its complex pathogenesis. Inositol polyphosphate-4-phosphatase type IA (INPP4A), a lipid phosphatase, has been implicated in allergic asthma. However, the expression and function of INPP4A in E-CRSwNP remain unclear. This study aims to investigate the role of INPP4A in macrophages in E-CRSwNP. METHODS: We assessed the expression of INPP4A in human and mouse nasal mucosal tissues via immunofluorescence staining. THP-1 cells were cultured and exposed to various cytokines to investigate the regulation of INPP4A expression and its functional role. Additionally, we established a murine nasal polyp (NP) model and administrated an INPP4A-overexpressing lentivirus evaluate its impact on NP. RESULTS: The percentage of INPP4A + CD68 + macrophages among total macrophages decreased in the E-CRSwNP group compared to the control and the non-eosinophilic CRSwNP (NE-CRSwNP) groups, exhibiting an inverse correlation with an increased percentage of CD206 + CD68 + M2 macrophages among total macrophages. Overexpression of INPP4A led to a reduced percentage of THP-1 cells polarizing towards the M2 phenotype, accompanied by decreased levels of associated chemotactic factors including CCL18, CCL22, CCL24, and CCL26. We also validated the involvement of the PI3K-AKT pathway in the function of INPP4A in vitro. Furthermore, INPP4A overexpression in the murine NP model resulted in the attenuation of eosinophilic inflammation in the nasal mucosa. CONCLUSIONS: INPP4A deficiency promotes macrophage polarization towards the M2 phenotype, leading to the secretion of chemokines that recruit eosinophils and Th2 cells, thereby amplifying eosinophilic inflammation in E-CRSwNP. INPP4A may exert a suppressive role in eosinophilic inflammation and could potentially serve as a novel therapeutic strategy.

A Multicenter Study of Prevalence and Risk Factors for Allergic Rhinitis in Primary School Children in 5 Cities of Hubei Province, China.

BACKGROUND: Few data are available concerning the prevalence and risk factors for allergic rhinitis (AR) in school children in Hubei Province which is located in the central part of China. This study investigated the epidemiological features of AR among school children in Hubei Province. METHODS: A cross-sectional questionnaire survey on AR in school children was carried out in 5 cities in Hubei Province by cluster sampling from June to September 2018. Questionnaires were filled out by children and their parents jointly. The diagnostic criteria of AR were according to the SFAR. Questions from the questionnaire were used to examine the pattern of AR. Logistic regression analysis was used to assess the risk factors for childhood allergies. RESULTS: The total prevalence rate of AR was 16.16%, with 24.31% (Wuhan), 4.34% (Xiangyang), 4.31% (Tianmen), 10.92% (Jingmen), and 11.42% (Huangshi), respectively. The prevalence of AR was positively correlated with gross domestic product per capita (p < 0.05). Multivariate analysis revealed that male, city of Wuhan, family history of allergy, food allergy, drug allergy, air purifier, exposure to dust, living in towns or urban area before 2 years old, maternal age for 26-35 years old, and frequent application of antibiotics increased the risk of AR, while daily outdoor time for 1-2 h, daily sleeping time >8 h, siblings, and breastfeeding for >6 months reduced the risk significantly. CONCLUSION: We found the apparent geographic variation of children allergies in Hubei Province. Both genetic and environment factors had impacts on the prevalence of AR in school children. Public policies should specifically target at the local risk factors for different areas.

The hMeDIP-Seq identified INPP4A as a novel biomarker for eosinophilic chronic rhinosinusitis with nasal polyps.

Background: Eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) is an endotype of chronic rhinosinusitis with nasal polyps characterized by more severe symptoms, a stronger association with asthma and a greater recurrence risk. It is unknown whether DNA hydroxymethylation could influence ECRSwNP. Methods: Hydroxymethylated DNA immunoprecipitation sequencing was carried out in three distinct groups (control, ECRSwNP and NECRSwNP). Additional qRT-PCR, immunohistochemistry and analysis of the receiver operating characteristic curve were performed. Results: Between ECRSwNP and NECRSwNP, 26 genes exhibited differential DNA hydroxymethylation. Consistent with their hydroxymethylation level, GNAL, INPP4A and IRF4 expression levels were significantly different between ECRSwNP and the other two groups. The receiver operating characteristic curve revealed that INPP4A mRNA has a high predictive accuracy for ECRSwNP. Conclusion: DNA hydroxymethylation regulates the expression of multiple genes in ECRSwNP. INPP4A mRNA was markedly decreased in ECRSwNP polyps and can predict ECRSwNP.