The ORMDL3 asthma gene regulates ICAM1 and has multiple effects on cellular inflammation
File(s)Zhang Polyomics of ORMDL3 and Airway Inflammation.docx (2.8 MB)
Accepted version
Author(s)
Type
Journal Article
Abstract
Rationale: Polymorphisms on chromosome 17q21 confer the major genetic susceptibility to childhood-onset asthma. Risk alleles positively correlate with ORMDL3 expression. The locus influences disease severity and the frequency of human rhinovirus (HRV) initiated exacerbations. ORMDL3 is known to regulate sphingolipid synthesis by binding serine palmitoyltransferase (SPT), but its role in inflammation is incompletely understood. Objectives: To investigate the role of ORMDL3 in cellular inflammation. Methods: We modelled time-series of IL1B-induced inflammation in A549 cells, using cytokine production as outputs and testing effects of ORMDL3 siRNA knockdown, ORMDL3 overexpression, and the SPT inhibitor myriocin. We replicated selected findings in normal human bronchial epithelial (NHBE) cells. Cytokine and metabolite levels were analysed by ANOVA. Transcript abundances were analysed by group means parameterisation, controlling the false discovery rate (FDR) below 0.05. Measurements and Main Results: Silencing ORMDL3 led to steroid-independent reduction of IL6 and IL8 release and reduced ER stress after IL1B. Overexpression and myriocin conversely augmented cytokine release. Knockdown reduced expression of genes regulating host-pathogen interactions, stress responses and ubiquitination: in particular ORMDL3 knockdown strongly reduced expression of the HRV receptor ICAM1. Silencing led to changes in levels of transcripts and metabolites integral to glycolysis. Increased levels of ceramides and the immune mediator sphingosine-1-P (S1P) were also observed. Conclusions: The results show ORMDL3 has pleiotropic effects during cellular inflammation, consistent with its substantial genetic influence on childhood asthma. Actions on ICAM1 provide a mechanism for the locus to confer susceptibility to HRV-induced asthma.
Date Issued
2019-02-15
Date Acceptance
2018-10-18
Citation
American Journal of Respiratory and Critical Care Medicine, 2019, 199 (4), pp.478-488
ISSN
1073-449X
Publisher
American Thoracic Society
Start Page
478
End Page
488
Journal / Book Title
American Journal of Respiratory and Critical Care Medicine
Volume
199
Issue
4
Copyright Statement
© 2018 by the American Thoracic Society
Sponsor
Wellcome Trust
Wellcome Trust
Identifier
https://www.atsjournals.org/doi/10.1164/rccm.201803-0438OC
Grant Number
096964/Z/11/Z
107059/Z/15/Z
Subjects
Science & Technology
Life Sciences & Biomedicine
Critical Care Medicine
Respiratory System
General & Internal Medicine
childhood asthma
ORMDL3
inflammation
ICAM1
EXPRESSION
ASSOCIATION
RECEPTOR
RISK
SUSCEPTIBILITY
METAANALYSIS
INFECTION
PROTEINS
LESSONS
OBESITY
ICAM1
ORMDL3
childhood asthma
inflammation
A549 Cells
Asthma
Cytokines
Endoplasmic Reticulum Stress
Gene Expression Profiling
Gene Knockdown Techniques
Humans
Inflammation
Interleukin-6
Interleukin-8
Membrane Proteins
Sphingolipids
Humans
Asthma
Inflammation
Sphingolipids
Membrane Proteins
Interleukin-8
Interleukin-6
Cytokines
Gene Expression Profiling
Gene Knockdown Techniques
Endoplasmic Reticulum Stress
A549 Cells
11 Medical and Health Sciences
Respiratory System
Publication Status
Published
Date Publish Online
2018-10-19