465 - Protein S-Acylation in Pulmonary Disease

Abstract

Obesity is a major risk factor for asthma. Obese asthmatics exhibit poor symptom control, frequent exacerbation, and increased levels of reactive oxygen species (ROS). The consumption of a western diet, high in fat and carbohydrates, can both induce obesity and increase ROS. Oxidation of critical cysteine resides, due to high ROS, may hinder post-translational modifications required for proper protein function. Previous studies reported that increased cysteine oxidation, due to consumption of a high-fat diet (HFD), coincided with decreased protein S-acylation. Protein S-acylation is regulated by acyltransferases (zDHHCs) and thioesterases (PPT/APTs). To date, there have been no reports of the S-acylated protein profile in the lung and how it may be modified by comorbid disease. We hypothesize that identifying the pulmonary ‘palmitoylome’ will provide critical information and insight into pathogenesis of lung disease, including the pathophysiology of asthma. The lung ‘palmitoylome’ was profiled by LC-MS analysis of S-acylated proteins isolated from murine whole lung tissue. Additionally, to measure alterations of pulmonary S-acylation in obesity and asthma, we used whole lung tissue of lean and obese, or house dust mite (HDM) allergic, C57BL/6 mice. To assess whether gene expression of zDHHC or PPT/APT enzymes was altered in obesity or asthma, RT-PCR was performed from lung tissue cDNA from the aforementioned mice. Furthermore, a microarray was conducted from human nasal epithelial cells isolated from obese asthmatic and non-asthmatic patients. We identified several S-acylated proteins in murine lung tissue. Differences in protein S-acylation as a result of feeding a HFD, as well as HDM-induced asthma, were observed. Although, gene expression of zDHHC enzymes was not altered in lung tissue, PPT/APT genes were significantly altered in lean vs. obese and healthy vs. allergic lung tissue. PPT and zDHHC gene expression was differentially expressed in the nasal epithelial cells from obese control vs. obese asthmatic patients. In conclusion, both obesity and asthma exhibit an altered protein S-acylation profile in murine lung tissue and in primary nasal epithelial cells from human subjects, which may contribute to pulmonary pathophysiology.