The epithelial-mesenchymal transition (EMT) is a complex process in which cell phenotype switches from the epithelial to mesenchymal one. The deregulations of this process have been related with the occurrence of different diseases such as lung cancer and fibrosis. In the last decade, several efforts have been devoted in understanding the mechanisms that trigger and sustain this transition process. Adenosine is a purinergic signaling molecule that has been involved in the onset and progression of chronic lung diseases and cancer through the A2B adenosine receptor subtype activation, too. However, the relationship between A2BAR and EMT has not been investigated, yet. Herein, the A2BAR characterization was carried out in human epithelial lung cells. Moreover, the effects of receptor activation on EMT were investigated in the absence and presence of transforming growth factor-beta (TGF-β1), which has been known to promote the transition. The A2BAR activation alone decreased and increased the expression of epithelial markers (E-cadherin) and the mesenchymal one (Vimentin, N-cadherin), respectively, nevertheless a complete EMT was not observed. Surprisingly, the receptor activation counteracted the EMT induced by TGF-β1. Several intracellular pathways regulate the EMT: high levels of cAMP and ERK1/2 phosphorylation has been demonstrated to counteract and promote the transition, respectively. The A2BAR stimulation was able to modulated these two pathways, cAMP/PKA and MAPK/ERK, shifting the fine balance toward activation or inhibition of EMT. In fact, using a selective PKA inhibitor, which blocks the cAMP pathway, the A2BAR-mediated EMT promotion were exacerbated, and conversely the selective inhibition of MAPK/ERK counteracted the receptor-induced transition. These results highlighted the A2BAR as one of the receptors involved in the modulation of EMT process. Nevertheless, its activation is not enough to trigger a complete transition, its ability to affect different intracellular pathways could represent a mechanism at the basis of EMT maintenance/inhibition based on the extracellular microenvironment. Despite further investigations are needed, herein for the first time the A2BAR has been related to the EMT process, and therefore to the different EMT-related pathologies.
@ERSpublications Although MRI resolution does not yet match that of CT, MRI can play an important role for functional imaging in patients with ILD. MRI can differentiate between inflammatory and fibrotic changes for monitoring targeted therapy in patients with ILD.ABSTRACT Thin-slices multi-detector computed tomography (MDCT) plays a key role in the differential diagnosis of interstitial lung disease (ILD). However, thin-slices MDCT has a limited ability to detect active inflammation, which is an important target of newly developed ILD drug therapy. Magnetic resonance imaging (MRI), thanks to its multi-parameter capability, provides better tissue characterisation than thin-slices MDCT.Our aim was to summarise the current status of MRI applications in ILD and to propose an ILD-MRI protocol. A systematic literature search was conducted for relevant studies on chest MRI in patients with ILD.We retrieved 1246 papers of which 55 original papers were selected for the review. We identified 24 studies comparing image quality of thin-slices MDCT and MRI using several MRI sequences. These studies described new MRI sequences to assess ILD parenchymal abnormalities, such as honeycombing, reticulation and ground-glass opacity. Thin-slices MDCT remains superior to MRI for morphological imaging. However, recent studies with ultra-short echo-time MRI showed image quality comparable to thin-slices MDCT. Several studies demonstrated the added value of chest MRI by using functional imaging, especially to detect and quantify inflammatory changes.We concluded that chest MRI could play a role in ILD patients to differentiate inflammatory and fibrotic changes and to assess efficacy of new ILD drugs.
Objectives
Lung ultrasound (LUS), through assessment of B-lines and pleural line alterations, is able to evaluate interstitial lung disease (ILD), a frequent complication of systemic sclerosis (SSc). Different scanning schemes and counting methods have been proposed, but no clear cut-off values have been indicated for screening. We aimed to evaluate the accuracy of different LUS methodological approaches to detect ILD, compared with high resolution computed tomography (HRCT) as gold standard.
Methods
Sixty-nine SSc patients underwent LUS and chest HRCT on the same day. Both exams were scored by expert readers. The accuracy of different scanning schemes and counting methods was assessed, and clinical and functional data were compared with imaging findings.
Results
B-lines were more numerous in patients with the diffuse skin subset and Scl70 autoantibody positivity. The number of B-lines correlated with the Scleroderma Lung Study (SLS) I HRCT score (R = 0.754, p< 0.0001). A total number >10 B-lines on the whole chest or > 1 B-line on the postero-basal chest showed 97% sensitivity for detecting even very early ILD signs (corresponding to SLS I score =1). Sensitivity increased to 100% when pleural line alterations were included in the analysis.
Conclusions
LUS has a very high sensitivity in detecting SSc-related ILD. A cut-off value of > 10 B-lines on the whole chest or > 1 B-line on the postero-basal chest can be used for the screening of SSc-ILD. Assessing only the postero-basal chest seems mostly effective to combine high sensitivity with a less time-consuming approach.
HRCT classification based on 2011 guidelines showed high accuracy in stratifying fibrotic changes because in our study UIP, possible UIP and inconsistent with UIP pattern seem to be correlated with different disease progression and mortality rate.
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