thermozymocidin and Pseudomonas-Infections

Our aim was to use quantitative and qualitative analyses to gain further insight into the role of ceramide in cystic fibrosis (CF). Sphingolipid ceramide is a known inflammatory mediator, and its accumulation in inflamed lung has been reported in different types of emphysema, chronic obstructive pulmonary disease and CF. CF is caused by a mutation of the chloride channel and associated with hyperinflammation of the respiratory airways and high susceptibility to ongoing infections. We have previously demonstrated that de novo ceramide synthesis is enhanced in lung inflammation and sustains Pseudomonas aeruginosa pulmonary infection in a CF murine model. We used liquid chromatography and matrix-assisted laser desorption/ionization (MALDI) imaging coupled with mass spectrometry, confocal laser scan microscopy and histology analyses to reveal otherwise undecipherable information. We demonstrated that (i) upregulated ceramide synthesis in the alveoli is strictly related to alveolar infection and inflammation, (ii) alveolar ceramide (C16) can be specifically targeted by nanocarrier delivery of the ceramide synthesis inhibitor myriocin (Myr) and (iii) Myr is able to downmodulate pro-inflammatory lyso-PC, favouring an increase in anti-inflammatory PCs. We concluded that Myr modulates alveolar lipids milieu, reducing hyperinflammation and favouring anti-microbial effective response in CF mouse model.

Topics: Animals; Ceramides; Cystic Fibrosis; Fatty Acids, Monounsaturated; Female; Inflammation; Lung; Male; Mice, Knockout; Nanoparticles; Pseudomonas aeruginosa; Pseudomonas Infections; Respiratory Tract Infections

Sphingolipids take part in immune response and can initiate and/or sustain inflammation. Various inflammatory diseases have been associated with increased ceramide content, and pharmacological reduction of ceramide diminishes inflammation damage in vivo. Inflammation and susceptibility to microbial infection are two elements in a vicious circle. Recently, sphingolipid metabolism inhibitors were used to reduce infection. Cystic fibrosis (CF) is characterized by a hyper-inflammation and an excessive innate immune response, which fails to evolve into adaptive immunity and to eradicate infection. Chronic infections result in lung damage and patient morbidity. Notably, ceramide content in mucosa airways is higher in CF mouse models and in patients than in control mice or healthy subjects.. The therapeutic potential of myriocin, an inhibitor of the sphingolipid de novo synthesis rate limiting enzyme (Serine Palmitoyl Transferase, SPT),was investigated in CF cells and mice models.. We treated CF human respiratory epithelial cells with myriocin, This treatment resulted in reduced basal, as well as TNFα-stimulated, inflammation. In turn, TNFα induced an increase in SPT in these cells, linking de novo synthesis of ceramide to inflammation. Furthermore, myriocin-loaded nanocarrier, injected intratrachea prior to P. aeruginosa challenge, enabled a significant reduction of lung infection and reduced inflammation.. The presented data suggest that de novo ceramide synthesis is constitutively enhanced in CF mucosa and that it can be envisaged as pharmacological target for modulating inflammation and restoring effective innate immunity against acute infection.. Myriocin stands as a powerful immunomodulatory agent for inflammatory and infectious diseases.

Topics: Animals; Anti-Inflammatory Agents; Antifungal Agents; Blotting, Western; Cell Proliferation; Ceramides; Chromatography, Liquid; Cystic Fibrosis; Drug Carriers; Enzyme-Linked Immunosorbent Assay; Fatty Acids, Monounsaturated; Female; Humans; Interleukin-6; Interleukin-8; Male; Mice; Mice, Inbred CFTR; Nanoparticles; Pseudomonas aeruginosa; Pseudomonas Infections; Real-Time Polymerase Chain Reaction; Respiratory Mucosa; Respiratory Tract Infections; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Sphingolipids