Large-scale profiling of signalling pathways reveals an asthma specific signature in bronchial smooth muscle cells

Abstract

BackgroundBronchial smooth muscle (BSM) cells from asthmatic patients maintain in vitro a distinct hyper-reactive (“primed”) phenotype, characterized by increased release of pro-inflammatory factors and mediators, as well as hyperplasia and/or hypertrophy. This “primed” phenotype helps to understand pathogenesis of asthma, as changes in BSM function are essential for manifestation of allergic and inflammatory responses and airway wall remodelling.ObjectiveTo identify signalling pathways in cultured primary BSMs of asthma patients and non-asthmatic subjects by genome wide profiling of differentially expressed mRNAs and activated intracellular signalling pathways (ISPs).MethodsTranscriptome profiling by cap-analysis-of-gene-expression (CAGE), which permits selection of preferentially capped mRNAs most likely to be translated into proteins, was performed in human BSM cells from asthmatic (n=8) and non-asthmatic (n=6) subjects and OncoFinder tool were then exploited for identification of ISP deregulations.ResultsCAGE revealed >600 RNAs differentially expressed in asthma vs control cells (p≤0.005), with asthma samples showing a high degree of similarity among them. Comprehensive ISP activation analysis revealed that among 269 pathways analysed, 145 (p<0.05) or 103 (p<0.01) are differentially active in asthma, with profiles that clearly characterize BSM cells of asthmatic individuals. Notably, we identified 7 clusters of coherently acting pathways functionally related to the disease, with ISPs down-regulated in asthma mostly targeting cell death-promoting pathways and up-regulated ones affecting cell growth and proliferation, inflammatory response, control of smooth muscle contraction and hypoxia-related signalization.ConclusionsThese first-time results can now be exploited toward development of novel therapeutic strategies targeting ISP signatures linked to asthma pathophysiology.

Upper and lower airway remodelling mechanisms in asthma, allergic rhinitis and chronic rhinosinusitis: The one airway concept revisited

“…58 Interestingly, large-scale transcriptional profiling analyses of ASM cells from asthmatic versus nonasthmatic subjects revealed a marked activation of pathways linked to cell proliferation and growth, vascularization, inflammatory response genes and muscle-tissue-specific responses, such as contractility in asthmatics. 59 Finally, ASM contraction can alter the mechanical properties of the airway wall, promoting mechanotransduction pathways that contribute to remodelling and initiating cascades that synergize with other inflammatory mechanisms. 60 Enhanced vascularity correlates with asthma severity 61 and is a key feature in the airways of people who died from asthma.…”

Data aggregation at the level of molecular pathways improves stability of experimental transcriptomic and proteomic data

“…3 OncoFinder has previously been applied to many human and non-human systems including cell culture, leukemia and solid cancers, fibrosis, asthma, Hutchinson Gilford and Age-Related Macular Degeneration Disease. [24][25][26][27] The PAS for a given pathway (p) is calculated as follows, 18 , PAS p D P n ARR np Álog CNR n ð Þ, where the functional role of the n th gene product in the pathway is indicated by the activator/repressor role (ARR), which equals 1 for an activator, -1 for a repressor, and intermediate values -0,5; 0,5 and 0 for gene products having intermediate repressor, activator, or unknown roles, respectively. The CNR n value (case-tonormal ratio) is the ratio of the expression level of gene n in the sample under investigation to the average expression level in the control samples.…”

The Three A’s in Asthma – Airway Smooth Muscle, Airway Remodeling & Angiogenesis

“…But this may change soon. Recently, we performed large-scale profiling analyses of signalling pathway activation signatures in ASM cells of asthmatic and non-asthmatic subjects [ 126 ]. Of the 270 studied signaling pathways, we observed that a substantial fraction of them was significantly more active in asthmatic ASM cells, so that ASM cells of asthmatic patients can be clearly distinguished from those of non-asthmatics.…”

“…Importantly, the identified pathways predominantly represented pathways linked to cell proliferation and growth, vascularization, inflammatory response and muscle-tissue specific responses, such as contractility. This study was the first to provide clear-cut evidence for an overall, intrinsic “primed” status of asthmatic ASM cells and may reflect the genetically predisposition of the disease [ 126 ].…”