Mechanistic Biomarker Responses in Human Bronchial Epithelial Air-Liquid Interface Cultures Following Exposure to Spray Cleaning Products

There are strong links between routine exposure to aerosolized cleaning products and epidemiologically observed adverse respiratory health outcomes, such as occupational asthma. However, because safety assessment relies largely on constituent-level information and mixture-classification rules, mechanistic data on the effects of complete cleaning formulations remain limited. In this study three commercially available all-purpose spray cleaners were investigated for early, localized cellular effects using an in vitro primary bronchial epithelial cells (PBEC) Air-Liquid Interface (ALI) model across three concentrations (10, 100, and 1000 ppm (v/v)). Transcriptional markers for oxidative stress, barrier integrity, and innate immunity were evaluated after 6hours of exposure, followed by protein quantification for IL-6, IL-8, MMP-9, and TIMP-1 at 18hours post-exposure period. Exposure to these three cleaning product formulations showed a persistent downregulation in GPX1 transcription across all products, indicating alterations in redox balance. Furthermore, one of the investigated formulations induced marked transcriptional changes in genes associated with epithelial barrier integrity (CDH1, CLDN1, CLDN4, and OCLN). Additionally, IL-8 secretion levels were significantly increased for all formulations. These findings demonstrated that these spray cleaners induce cellular responses in bronchial epithelial models in a formulation-dependent manner. By investigating distinct cellular pathways critical to integrity and their responses following chemical assault, these findings provide insights into the pathogenic processes of respiratory effects associated to cleaning-product-exposures.