[PDF][PDF] Inhibition of sphingolipid synthesis as a phenotype-modifying therapy in cystic fibrosis.

A Mingione, M Dei Cas, F Bonezzi, A Caretti… - Cellular Physiology & …, 2020 - air.unimi.it
A Mingione, M Dei Cas, F Bonezzi, A Caretti, M Piccoli, L Anastasia, R Ghidoni, R Paroni
Cellular Physiology & Biochemistry (Cell Physiol Biochem Press GmbH & Co. KG), 2020air.unimi.it
Abstract Background/Aims: Cystic Fibrosis (CF) is an inherited disease associated with a
variety of mutations affecting the CFTR gene. A deletion of phenylalanine 508 (F508) affects
more than 70% of patients and results in unfolded proteins accumulation, originating a
proteinopathy responsible for inflammation, impaired trafficking, altered metabolism,
cholesterol and lipids accumulation, impaired autophagy at the cellular level. Lung
inflammation has been extensively related to the accumulation of the lipotoxin ceramide. We …
Background/Aims
Cystic Fibrosis (CF) is an inherited disease associated with a variety of mutations affecting the CFTR gene. A deletion of phenylalanine 508 (F508) affects more than 70% of patients and results in unfolded proteins accumulation, originating a proteinopathy responsible for inflammation, impaired trafficking, altered metabolism, cholesterol and lipids accumulation, impaired autophagy at the cellular level. Lung inflammation has been extensively related to the accumulation of the lipotoxin ceramide. We recently proved that inhibition of ceramide synthesis by Myriocin reduces inflammation and ameliorates the defence response against pathogens infection, which is downregulated in CF. Here, we aim at demonstrating the mechanisms of Myriocin therapeutic effects in Cystic Fibrosis broncho-epithelial cells.
Methods
The effect of Myriocin treatment, on F508-CFTR bronchial epithelial cell line IB3-1 cells, was studied by evaluating the expression of key proteins and genes involved in autophagy and lipid metabolism, by western blotting and real time PCR. Moreover, the amount of glycerolphospholipids, triglycerides, and cholesterols, sphingomyelins and ceramides were measured in treated and untreated cells by LC-MS. Finally, Sptlc1 was transiently silenced and the effect on ceramide content, autophagy and transcriptional activities was evaluated as above mentioned.
Results
We demonstrate that Myriocin tightly regulates metabolic function and cell resilience to stress. Myriocin moves a transcriptional program that activates TFEB, major lipid metabolism and autophagy regulator, and FOXOs, central lipid metabolism and antiinflammatory/anti-oxidant regulators. The activity of these transcriptional factors is associated with the induction of PPARs nuclear receptors activity, whose targets are genes involved in lipid
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