Identification of Potential Leukocyte Biomarkers Related to Drug Recovery of CFTR: Clinical Applications in Cystic Fibrosis

Abstract

The aim of this study was the identification of specific proteomic profiles, related to a restored cystic fibrosis transmembrane conductance regulator (CFTR) activity in cystic fibrosis (CF) leukocytes before and after ex vivo treatment with the potentiator VX770. We used leukocytes, isolated from CF patients carrying residual function mutations and eligible for Ivacaftor therapy, and performed CFTR activity together with proteomic analyses through micro-LC–MS. Bioinformatic analyses of the results obtained revealed the downregulation of proteins belonging to the leukocyte transendothelial migration and regulation of actin cytoskeleton pathways when CFTR activity was rescued by VX770 treatment. In particular, we focused our attention on matrix metalloproteinase 9 (MMP9), because the high expression of this protease potentially contributes to parenchyma lung destruction and dysfunction in CF. Thus, the downregulation of MMP9 could represent one of the possible positive effects of VX770 in decreasing the disease progression, and a potential biomarker for the prediction of the efficacy of therapies targeting the defect of Cl− transport in CF.

Emerging Concepts in Defective Macrophage Phagocytosis in Cystic Fibrosis

“…A limited description of specific affected proteins involved in phagocytosis was provided, however proteins such as LEMD2 (transmembrane adapter for ESCRT) and ACTG1 were altered by ivacaftor, suggesting a potential impact on degradative and actin-related processes. In a separate proteomics study, several proteins involved in the regulation of actin cytoskeleton and leukocyte trans-endothelial migration were strongly downregulated in CF monocytes carrying residual function CFTR variants after treatment with ivacaftor [ 177 ]. In a fourth study, people with CF treated with lumacaftor/ivacaftor had a lower expression of CXCR2 (receptor for IL-8) on CD14+ CD16- monocytes compared to healthy controls.…”

Immortalization and Characterization of Rat Lingual Keratinocytes in a High-Calcium and Feeder-Free Culture System Using ROCK Inhibitor Y-27632

“…The label-free quantitation was performed through MS signal intensity with total peptide normalization. The abundances of the proteins, exported by PD 2.4 software, were used for PCA and hierarchical cluster analysis using MetaboAnalyst 5.0 (www.metaboanalyst.org; Date accessed: 12 May 2021) [60]. Proteins with an adjusted p-value < 0.01 and a fold change ≥2 were considered differentially expressed.…”

Revisiting the Role of Leukocytes in Cystic Fibrosis

“…Indeed, studies on CFTR deficient pigs have shown altered responses of monocytes to pathogens tested on Pseudomonas aeruginosa infections [ 40 ], are in agreement with other modeling systems demonstrating a difference between the CFTR deficient environment and the healthy, non-CF environment [ 41 , 42 , 43 , 44 ]. These data not only underline the clinical relevance of these cells, but also suggest that probing CFTR expression/activity and associated biomarkers such as metalloproteinase 9 (MMP9) in peripheral blood leukocytes might have a possible clinical application such as the monitoring the efficacy of CFTR modulators [ 45 , 46 , 47 , 48 ].…”

“…Considering that the clinical responses to CFTR modulators vary by, and even within, genotypes [ 68 , 69 , 70 , 71 ], and also that studies examining individuals before and after initiation of CFTR modulators have shown that these molecules do not reverse all disease manifestations [ 66 , 67 , 72 ], it is of great relevance to find biomarkers for monitoring therapies, particularly those predictive of an individual patient’s response. In the last decade, many studies have indicated that leukocytes, being easily and quickly isolated from patients, can be non-epithelial cellular models useful to monitor the responses of CF patients to the treatment during clinical trials and also as potential predicting biomarkers of the efficacy of therapies [ 45 , 47 , 73 ]. To this end, several approaches have been adopted.…”

“…These findings revealed that multiple transcriptional programs, including the pathways associated with immunity and inflammation, are modified in circulating CF monocytes after ivacaftor treatment. Moreover, Pedrazzi et al combined the two approaches together identifying changes in specific proteomic profiles related to restored CFTR activity in CF leukocytes after ex vivo treatment with ivacaftor [ 47 ]. The limitation of these studies is that the changes considered in these cells following initiation of CFTR modulators were generally evaluated at only one time point.…”