A Novel Lipidomic Strategy Reveals Plasma Phospholipid Signatures Associated with Respiratory Disease Severity in Cystic Fibrosis Patients

Abstract

The aim of this study was to search for lipid signatures in blood plasma from cystic fibrosis (CF) patients using a novel MALDI-TOF-ClinProTools™ strategy, initially developed for protein analysis, and thin layer chromatography coupled to MALDI-TOF (TLC-MALDI). Samples from 33 CF patients and 18 healthy children were subjected to organic extraction and column chromatography separation of lipid classes. Extracts were analyzed by MALDI-TOF, ion signatures were compared by the ClinProTools™ software and by parallel statistical analyses. Relevant peaks were identified by LC-MSn. The ensemble of analyses provided 11 and 4 peaks differentially displayed in CF vs healthy and in mild vs severe patients respectively. Ten ions were significantly decreased in all patients, corresponding to 4 lysophosphatidylcholine (18∶0, 18∶2, 20∶3, and 20∶5) and 6 phosphatidylcholine (36∶5, O-38∶0, 38∶4, 38∶5, 38∶6, and P-40∶1) species. One sphingolipid, SM(d18∶0), was significantly increased in all patients. Four PC forms (36∶3, 36∶5, 38∶5, and 38∶6) were consistently downregulated in severe vs mild patients. These observations were confirmed by TLC-MALDI. These results suggest that plasma phospholipid signatures may be able to discriminate mild and severe forms of CF, and show for the first time MALDI-TOF-ClinProTools™ as a suitable methodology for the search of lipid markers in CF.

Plasma lipidomics reveals potential prognostic signatures within a cohort of cystic fibrosis patients

“…At t = 3, neutral lipids (cholesterol, cholesterol esters, and TAG) were no longer associated with chronic infection, unlike LPC(18:0), which was signifi cantly increased in individuals noncolonized by Pseudomonas aeruginosa . In our previous study of plasma from CF patients and healthy siblings, PC and LPC species, including LPC(18:0) and PC(36:4), were suggested to be associated with the severity status of patients ( 21 ). Our fi ndings in the current work are somehow in accordance with those previous data and represent a new dimension in that prognostic value is suggested.…”

“…Second, the highest and most signifi cant correlations corresponded to n-3 fatty acids. Saturated, monounsaturated, and n-6 PUFA presented similar, but not signifi cant, trends found differentially displayed in the plasma from patients and associated with severity status in our previous study ( 21 ). We also included free fatty acids, as they represent in plasma an important component of what has been traditionally analyzed in fatty acid profi ling.…”

“…In a recent paper, we have shown altered phospholipid plasma content associated with both the onset and severity status of the disease ( 21 ). In the present work, we have addressed the same question by analyzing the plasma lipid composition of CF patients in a cohort composed exclusively of F508del homozygotes who shared the same treatment modalities and follow-up from one clinical center.…”

“…On the basis of our previous results ( 21,24 ) and reports by others ( 35-37 ), we fi rst focused our lipidomic screening on 50 lipid molecules or entities. After multiple Pearson correlation analysis of the lipid values at t = 0 with FEV1 measured at sampling time, a series of lipid signatures were found correlated with this respiratory functional parameter (n = 29, p < 0.05).…”

Lipid mapping of colonic mucosa by cluster TOF-SIMS imaging and multivariate analysis in cftr knockout mice

“…This approach presents its limitations in studies where there is not an a priori molecular target or in the absence of a known disease marker. The alternative strategy is the use of multivariate analyses, where the effects of more than one statistical variable on the parameter of interest are Another aspect that is hardly explained as a consequence of CFTR dysfunction is the presence of alterations in the metabolism and in the blood and tissue content of certain lipids ( 9 ) (polyunsaturated fatty acids ( 10,11 ), phospholipids ( 12,13 ), sphingolipids ( 14,15 ), and cholesterol ( 16 )). Nevertheless, these fi ndings have been addressed by biochemical methods on total tissue homogenates or by chemical imaging of lipid analogs in cell models.…”