Da Hong1, Yuanyuan Qi1, Jing Liu1, Huijun Wang2, Libo Wang1, Liling Qian1. 1. Department of Respiratory Medicine, Children's Hospital of Fudan University, Shanghai, China. 2. The Molecular Genetic Diagnosis Center, Shanghai Key Lab of Birth Defects, Institute for Pediatric Research, Children's Hospital of Fudan University, Shanghai, China.
Abstract
BACKGROUND: Mutations in the surfactant protein C gene (SFTPC) result in interstitial lung disease (ILD). Our objective was to report a novel SFTPC mutation and evaluate the effect of this mutant on protein synthesis and processing. METHODS: Genomic DNA was extracted from whole blood of a Chinese infant with ILD and candidate genes associated with ILD were sequenced by next-generation sequencing. Subclones of wild-type and mutant SFTPC were transiently transfected into A549 cells. The functional characterization of mutant surfactant protein C (SP-C) was evaluated by Western blotting, transmission electron microscopy, and immunofluorescence. RESULTS: A novel heterozygous mutation SFTPC: c.337T>T/C, p.Y113H was identified in this ILD infant. Neither of the parents carries this mutation. Using A549 cells expressing wild-type and mutant SP-C isoforms, Western blotting revealed a significant reduction of proSP-C and a band with abnormal molecular weight in the mutant SP-C compared to the wild-type. Ultrastructural analysis showed abnormal cytoplasmic organelles. Immunofluorescence demonstrated mutant SP-C was scarcely trafficked to lamellar bodies but localized well to early endosomes, which was in marked contrast to the wild type protein. CONCLUSION: We detected a novel mutation in SFTPC causing ILD in infancy. The mutation results in aberrant proSP-C processing and altered subcellular localization.
BACKGROUND: Mutations in the surfactant protein C gene (SFTPC) result in interstitial lung disease (ILD). Our objective was to report a novel SFTPC mutation and evaluate the effect of this mutant on protein synthesis and processing. METHODS: Genomic DNA was extracted from whole blood of a Chinese infant with ILD and candidate genes associated with ILD were sequenced by next-generation sequencing. Subclones of wild-type and mutant SFTPC were transiently transfected into A549 cells. The functional characterization of mutant surfactant protein C (SP-C) was evaluated by Western blotting, transmission electron microscopy, and immunofluorescence. RESULTS: A novel heterozygous mutation SFTPC: c.337T>T/C, p.Y113H was identified in this ILD infant. Neither of the parents carries this mutation. Using A549 cells expressing wild-type and mutant SP-C isoforms, Western blotting revealed a significant reduction of proSP-C and a band with abnormal molecular weight in the mutant SP-C compared to the wild-type. Ultrastructural analysis showed abnormal cytoplasmic organelles. Immunofluorescence demonstrated mutant SP-C was scarcely trafficked to lamellar bodies but localized well to early endosomes, which was in marked contrast to the wild type protein. CONCLUSION: We detected a novel mutation in SFTPC causing ILD in infancy. The mutation results in aberrant proSP-C processing and altered subcellular localization.
Authors: William E Lawson; Peter F Crossno; Vasiliy V Polosukhin; Juan Roldan; Dong-Sheng Cheng; Kirk B Lane; Thomas R Blackwell; Carol Xu; Cheryl Markin; Lorraine B Ware; Geraldine G Miller; James E Loyd; Timothy S Blackwell Journal: Am J Physiol Lung Cell Mol Physiol Date: 2008-04-04 Impact factor: 5.464
Authors: L Guillot; R Epaud; G Thouvenin; L Jonard; A Mohsni; R Couderc; F Counil; J de Blic; R A Taam; M Le Bourgeois; P Reix; F Flamein; A Clement; D Feldmann Journal: J Med Genet Date: 2009-05-13 Impact factor: 6.318
Authors: David Scheuring; Fabian Künzl; Corrado Viotti; Melody San Wan Yan; Liwen Jiang; Swen Schellmann; David G Robinson; Peter Pimpl Journal: BMC Plant Biol Date: 2012-09-12 Impact factor: 4.215