Cystic fibrosis Airway primary epithelial cells in air-liquid interrface culture show abnormal inflammation and lipid metabolism related RNA expresssion compared to non-CF

A deficiency in cystic fibrosis transmembrane conductance regulator (CFTR) function in cystic fibrosis (CF) leads to chronic lung disease. However, the molecular mechanisms are not well understood and therapies that can help all patients remain elusive. CF is associated with abnormalities in fatty acids, ceramides and cholesterol, therefore we examined the impact of CFTR deficiency on lipid metabolism and pro-inflammatory signaling in airway epithelium using mass spectrometric, protein array and RNAseq analyses. We observed a striking imbalance in fatty acid and ceramide metabolism, associated with chronic oxidative stress under basal conditions in CF mouse lung and well differentiated bronchial epithelial cell cultures of CFTR knock out pig and CF patients. Cell autonomous features of all three CF models included high ratios of ω-6- to ω-3-polyunsaturated fatty acids and long- to very long- chain ceramide species (LCC/VLCC). The anti-oxidants glutathione (GSH) and deferoxamine partially corrected the lipid profile indicating that oxidative stress may promote the lipid abnormalities. CFTR-targeted modulators reduced the lipid imbalance and apparent oxidative stress, confirming the CFTR dependence of lipid ratios. RNA sequencing and protein array analysis revealed higher expression and shedding of cytokines and growth factors from CF epithelial cells compared to non-CF cells, consistent with sterile inflammation and tissue remodeling under basal conditions. Treatment with antioxidants or CFTR modulators that mimic the approved combination therapies, Orkambi and Trikafta, did not suppress the inflammatory phenotype. These results suggest that anti-inflammatory therapies may provide additional benefit for CF patients taking CFTR modulator drugs. Overall design: Here we report analysis of nine samples, three of Cf patient (BCF000174), homozygous for F508del CFTR, compared to two non-CF in triplicate each (P21, P11, ErasmusMC, Rotterdam, compared pairwise)

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Veltman M, De Sanctis JB, Stolarczyk M, Klymiuk N, Bähr A, Brouwer RW, Oole E, Shah J, Ozdian T, Liao J, Martini C, Radzioch D, Hanrahan JW, Scholte BJ