Gene expression in asthmatic airway smooth muscle: a mixed bag

CD Pascoe, NE Swyngedouw… - Canadian journal of …, 2015 - cdnsciencepub.com
Canadian journal of physiology and pharmacology, 2015cdnsciencepub.com
It has long been known that airway smooth muscle (ASM) contraction contributes
significantly to the reversible airflow obstruction that defines asthma. It has also been
postulated that phenotypic changes in ASM contribute to the airway hyper-responsiveness
(AHR) that is a characteristic feature of asthma. Although there is agreement that the mass of
ASM surrounding the airways is significantly increased in asthmatic compared with non-
asthmatic airways, it is still uncertain whether there are quantitative or qualitative changes in …
It has long been known that airway smooth muscle (ASM) contraction contributes significantly to the reversible airflow obstruction that defines asthma. It has also been postulated that phenotypic changes in ASM contribute to the airway hyper-responsiveness (AHR) that is a characteristic feature of asthma. Although there is agreement that the mass of ASM surrounding the airways is significantly increased in asthmatic compared with non-asthmatic airways, it is still uncertain whether there are quantitative or qualitative changes in the level of expression of the genes and proteins involved in the canonical contractile pathway in ASM that could account for AHR. This review will summarize past attempts at quantifying gene expression changes in the ASM of asthmatic lungs as well as non-asthmatic ASM cells stimulated with various inflammatory cytokines. The lack of consistent findings in asthmatic samples coupled with the relative concordance of results from stimulated ASM cells suggests that changes to the contractility of ASM tissues in asthma may be dependent on the presence of an inflammatory environment surrounding the ASM layer. Removal of the ASM from this environment could explain why hypercontractility is rarely seen ex vivo.
Canadian Science Publishing