Methylprednisolone pulse treatment improves ProSP-C trafficking in twins with SFTPC mutation: An isoform story?
| Autor: | Ralph Epaud, Pascale Fanen, Abdel Aissat, Agathe Tarze, Elodie Nattes, Stéphanie Finet, Céline Delestrain, Valérie Delattre, Stéphanie Simon, Bruno Costes, Elodie Duprat |
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| Rok vydání: | 2020 |
| Předmět: |
Gene isoform
Protein isoform Mutant Twins ABCA3 medicine.disease_cause 030226 pharmacology & pharmacy Methylprednisolone 03 medical and health sciences 0302 clinical medicine medicine Humans Protein Isoforms Pharmacology (medical) 030212 general & internal medicine Pharmacology Messenger RNA Mutation biology Wild type Surfactant protein C respiratory system Molecular biology Pulmonary Surfactant-Associated Protein C A549 Cells biology.protein Lung Diseases Interstitial |
| Zdroj: | British journal of clinical pharmacologyREFERENCES. 87(5) |
| ISSN: | 1365-2125 |
| Popis: | Mutations in the gene encoding surfactant protein C (SP-C) cause interstitial lung disease (ILD), and glucocorticosteroid (GC) treatment is the most recognized therapy in children. We aimed to decipher the mechanisms behind successful GC treatment in twins carrying a BRICHOS c.566G > A (p.Cys189Tyr) mutation in the SP-C gene (SFTPC). METHODS: The twins underwent bronchoscopy before and after GC treatment and immunoblotting analysis of SP-C proprotein (proSP-C) and SP-C mature in bronchoalveolar fluid (BALF). Total RNA was extracted and analysed using quantitative real-time PCR assays. In A549 cells, the processing of mutated protein C189Y was studied by immunofluorescence and immunoblotting after heterologous expression of eukaryotic vectors containing wild type or C189Y mutant cDNA. RESULTS: Before treatment, BALF analysis identified an alteration of the proSP-C maturation process. Functional study of C189Y mutation in alveolar A549 cells showed that pro-SP-CC189Y was retained within the endoplasmic reticulum together with ABCA3. After 5 months of GC treatment with clinical benefit, the BALF analysis showed an improvement of proSP-C processing. SFTPC mRNA analysis in twins revealed a decrease in the expression of total SFTPC mRNA and a change in its splicing, leading to the expression of a second shorter proSP-C isoform. In A549 cells, the processing and the stability of this shorter wild-type proSP-C isoform was similar to that of the longer isoform, but the half-life of the mutated shorter isoform was decreased. These results suggest a direct effect of GC on proSP-C metabolism through reducing the SFTPC mRNA level and favouring the expression of a less stable protein isoform. |
| Databáze: | OpenAIRE |
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