PURPOSE: Myeloid differentiation-2 (MD-2) has been associated with endotoxin and inflammatory disorders because it can recognize lipopolysaccharide (LPS) binding and attenuate Toll-like receptor 4 (TLR4)-mediated signaling. However, its role in allergic inflammation has yet to be clarified. We examined whether single nucleotide polymorphisms (SNPs) in MD-2 promoter can affect MD-2 expression and aimed to clarify the relationship between Der p 2 allergy and SNPs of MD-2 promoter. METHODS: The function of SNPs of MD-2 promoter and the effects of cytokines and immunoglobulin on the secretion and mRNA expression were investigated in 73 allergic subjects with different MD-2 gene promoter variants. Peripheral blood mononuclear cells were cultured with or without LPS in the presence of Dermatophagoides pteronyssinus group 2 allergen (Der p 2), followed by mRNA extraction and cytokine expression analysis. The culture supernatants were collected for cytokine measurement. RESULTS: Patients with the MD-2 promoter SNPs (rs1809441/rs1809442) had increased mRNA expressions of MD-2, epsilon heavy chain of IgE (Cepsilon), and interleukin (IL)-8; however, only MD-2 and IL-8 were further up-regulated after Der p 2 stimulation. Patients with SNPs of MD-2 promoter tended to have high levels of IL-1beta, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-alpha after Der p 2 and LPS stimulation. Increased secretions of IL-6, IL-8, and IL-10 were found to be up-regulated by Der p 2 stimulation, and an increased secretion of IFN-gamma and decreased secretion of IL-4 were noted after LPS stimulation. CONCLUSIONS: The high levels of proinflammatory cytokines secreted by Der p 2 were predetermined by MD-2 promoter SNPs (rs1809441/rs1809442). Through cytokine secretion by Der p 2 and LPS, these SNPs may serve as an indicator of the pathological phenotype of Der p 2-induced allergic inflammation.
Cytokines ; Dermatophagoides pteronyssinus ; Humans ; Hypersensitivity ; Immunoglobulin E ; Immunoglobulins ; Inflammation* ; Interleukin-10 ; Interleukin-4 ; Interleukin-6 ; Interleukin-8 ; Interleukins ; Phenotype ; Polymorphism, Single Nucleotide ; RNA, Messenger ; Toll-Like Receptor 4 ; Tumor Necrosis Factor-alpha

Objective: Emerging evidence suggests that air pollution exposure may increase the risk of Parkinson’s disease (PD). We aimed to investigate the association between exposure to fine particulate matter (PM2.5) and the risk of incident PD nationwide. Methods: We utilized data from the Taiwan National Health Insurance Research Database, which is spatiotemporally linked with air quality data from the Taiwan Environmental Protection Administration website. The study population consisted of participants who were followed from the index date (January 1, 2005) until the occurrence of PD or the end of the study period (December 31, 2017). Participants who were diagnosed with PD before the index date were excluded. To evaluate the association between exposure to PM2.5 and incident PD risk, we employed Cox regression to estimate the hazard ratio and 95% confidence interval (CI). Results: A total of 454,583 participants were included, with a mean (standard deviation) age of 63.1 (9.9) years and a male proportion of 50%. Over a mean follow-up period of 11.1 (3.6) years, 4% of the participants (n = 18,862) developed PD. We observed a significant positive association between PM2.5 exposure and the risk of PD, with a hazard ratio of 1.22 (95% CI, 1.20–1.23) per interquartile range increase in exposure (10.17 μg/m3) when adjusting for both SO2 and NO2. Conclusion We provide further evidence of an association between PM2.5 exposure and the risk of PD. These findings underscore the urgent need for public health policies aimed at reducing ambient air pollution and its potential impact on PD.