HSP70 upregulation in nasal mucosa of symptomatic children with allergic rhinitis and potential risk of asthma development

Dissecting the pathogenic effects of smoking in blood DNA methylation on allergic diseases

Background

Allergic diseases, such as asthma and allergic rhinitis, present significant health challenges globally. Elucidating the genetic and epigenetic foundations is crucial for developing effective interventions.

Methods

We performed two-sample Mendelian Randomization (MR) analyses to investigate the associations between smoking behaviors and various allergic diseases, leveraging data from the FinnGen database. Additionally, we examined the relationships of DNA methylation (CpG sites) with allergic diseases, employing mQTLs as epigenetic proxies. Furthermore, we conducted reverse MR analyses on CpG sites that exhibited cross-allergic disease effects.

Results

In our genomic MR analysis, smoking behaviors such as smoking initiation and the number of cigarettes smoked per day were identified to be causally associated with an increased risk of asthma. Additionally, there was suggestive evidence linking smoking initiation to atopic contact dermatitis. Our epigenetic MR analysis found that methylation changes at 46 CpG sites, assessed via mQTLs, were significantly associated with asthma risk. Notably, cg17272563 (PRRT1), cg03689048 (BAT3), cg20069688 (STK19), and cg20513976 (LIME1) were identified with cross-allergic effects. Crucially, reverse MR analysis substantiated these associations.

Conclusions

Our study has highlighted the associations between smoking behaviors and allergic diseases in the genetic and epigenetic landscape, notably asthma. We identified several DNA methylation-related CpG sites, such as cg03689048 (BAT3), cg17272563 (PRRT1), and cg20069688 (STK19), which demonstrate cross-allergic potential and reverse causal relationships.

Production and Release of Proinflammatory Mediators by the Cockroach Allergen Bla g 1 via a Shared Membrane-Destabilization Mechanism

The cockroach allergen Bla g 1 encloses an exceptionally large hydrophobic cavity, which allows it to bind and deliver unsaturated fatty acid ligands. Bla g 1-mediated delivery of naturally occurring (nMix) ligands has been shown to destabilize lipid membranes, contributing to its digestive/antiviral functions within the source organism. However, the consequences of this activity on Bla g 1 allergenicity following human exposure remain unknown. In this work, we show that Bla g 1-mediated membrane disruption can induce a proinflammatory immune response in mammalian cells via two complementary pathways. At high concentrations, the cytotoxic activity of Bla g 1 induces the release of proinflammatory cytosolic contents including damage-associated molecular patterns (DAMPs) such as heat-shock Protein-70 (HSP70) and the cytokine interleukin-1 (IL-1β). Sublytic concentrations of Bla g 1 enhanced the ability of phospholipase A2 (PLA2) to extract and hydrolyze phospholipid substrates from cellular membranes, stimulating the production of free polyunsaturated fatty acids (PUFAs) and various downstream inflammatory lipid mediators. Both of these effects are dependent on the presence of Bla g 1's natural fatty-acid (nMix) ligands with CC50 values corresponding to the concentrations required for membrane destabilization reported in previous studies. Taken together, these results suggest that mechanisms through which Bla g 1-mediated lipid delivery and membrane destabilization could directly contribute to cockroach allergic sensitization.

Albumin Proteins as Delivery Vehicles for PFAS Contaminants into Respiratory Membranes

Poly- and perfluoroalkyl substances (PFAS) are a family of chemicals that have been used in a wide range of commercial products. While their use is declining, the prevalence of PFAS, combined with their chemical longevity, ensures that detectable levels will remain in the environment for years to come. As such, there is a pressing need to understand how PFAS contaminants interact with other elements of the human exposome and the consequences of these interactions for human health. Using serum albumin as a model system, we show that proteins can bind PFAS contaminants and facilitate their incorporation into model pulmonary surfactant systems and lipid bilayers. Protein-mediated PFAS delivery significantly altered the structure and function of both model membrane systems, potentially contributing to respiratory dysfunction and airway diseases in vivo. These results provide valuable insights into the synergistic interaction between PFAS contaminants and other elements of the human exposome and their potential consequences for human health.