New insights into the pathogenesis of autosomal‐dominant cutis laxa with report of fiveELNmutations

作者：Bert Louis Callewaert, Marjolijn Renard, Vishwanathan Hucthagowder, Beate Albrecht, Ingrid Haußer, Edward M. Blair, Cristina Dias, Alice Albino, Hiroshi Wachi, Fumiaki Sato, Robert P. Mecham, Bart Loeys, Paul J. Coucke, Anne De Paepe, Zsolt Urbán · 发表于：Human Mutation · 年份：2011 · DOI：10.1002/humu.21462 · 被引用次数：135 · 研究领域：Connective tissue disorders research、Dermatological and Skeletal Disorders、Hypertrophic osteoarthropathy and related conditions

Autosomal dominant cutis laxa (ADCL) is characterized by a typical facial appearance and generalized loose skin folds, occasionally associated with aortic root dilatation and emphysema. We sequenced exons 28-34 of the ELN gene in five probands with ADCL features and found five de novo heterozygous mutations: c.2296_2299dupGCAG (CL-1), c.2333delC (CL-2), c.2137delG (CL-3), c.2262delA (monozygotic twin CL-4 and CL-5), and c.2124del25 (CL-6). Four probands (CL-1,-2,-3,-6) presented with progressive aortic root dilatation. CL-2 and CL-3 also had bicuspid aortic valves. CL-2 presented with severe emphysema. Electron microscopy revealed elastic fiber fragmentation and diminished dermal elastin deposition. RT-PCR studies showed stable mutant mRNA in all patients. Exon 32 skipping explains a milder phenotype in patients with exon 32 mutations. Mutant protein expression in fibroblast cultures impaired deposition of tropoelastin onto microfibril-containing fibers, and enhanced tropoelastin coacervation and globule formation leading to lower amounts of mature, insoluble elastin. Mutation-specific effects also included endoplasmic reticulum stress and increased apoptosis. Increased pSMAD2 staining in ADCL fibroblasts indicated enhanced transforming growth factor beta (TGF-β) signaling. We conclude that ADCL is a systemic disease with cardiovascular and pulmonary complications, associated with increased TGF-β signaling and mutation-specific differences in endoplasmic reticulum stress and ...