Project description:Fibrillins are the major components of microfibrils in the extracellular matrix of elastic and non-elastic tissues. Fibrillin-1 contains one evolutionarily conserved Arg-Gly-Asp (RGD) sequence which mediates cell-matrix interactions through cell-surface integrins. Mutations in close vicinity to the RDG sequence lead to heritable disorders, including Marfan syndrome and stiff skin syndrome. Two recombinant fibrillin-1 fragments were produced, one wild-type RGD-containing fragment and one fragment containing a mutant RGA sequence, which has been previously shown to abolish interactions with integrins. To determine the differential regulation of signaling pathways, microarray analysis of mRNA expression was conducted using Affymetrix Human Gene 2.0 ST chips. The mRNA expression levels were compared after 24 hours of interaction between human skin fibroblasts (HSFs) and the RGD- and RGA-containing fibrillin-1 fragments.
Project description:Fibrillins are the major components of microfibrils in the extracellular matrix of elastic and non-elastic tissues. Fibrillin-1 contains one evolutionarily conserved Arg-Gly-Asp (RGD) sequence which mediates cell-matrix interactions through cell-surface integrins. Mutations in close vicinity to the RDG sequence lead to heritable disorders, including Marfan syndrome and stiff skin syndrome. Two recombinant fibrillin-1 fragments were produced, one wild-type RGD-containing fragment and one fragment containing a mutant RGA sequence, which has been previously shown to abolish interactions with integrins. To determine the differential regulation of signaling pathways, microarray analysis of microRNA expression was conducted using Affymetrix miRNA3.0 chips. The microRNA expression levels were compared after 24 hours of interaction between human skin fibroblasts (HSFs) and the RGD- and RGA-containing fibrillin-1 fragments.
Project description:The Mg-delta strain of fibrillin-1 deficient mice display an early defect in alveolar septation. This study attempts to identify expression patterns in the mutant mouse lung compared to their wild-type littermates that suggest pathways that are critical for normal septation. This experiment focuses on postnatal days 1 and 5. Other time points will be added at a later date.
Project description:Mutations in the fibrillin-1 gene result in cardiovascular, ocular, and skeletal abnormalities in Marfan syndrome. Here we show that a fibrillin-1 mutation also alters the neovessel formation. In the mouse retina vascularization model, fibrillin-1 is detected at the basement membrane underlying the angiogenic front and around arterioles. In Fbn1C1041G/+ mice, a model of Marfan disease, the microvasculature is altered at these sites. At the front, endothelial tip-cell sprouting and branching are decreased, and we show that mutant fibrillin-1 delays angiogenesis by affecting Notch signalling. Supplying the growing vasculature of Fbn1C1041G/+ mice with a C-terminal fragment of fibrillin-1 corrects all defects. In vitro, the C-terminal fragment of fibrillin-1 also displays pro-angiogenic activities on microvascular endothelial cell. Our data establish that fibrillin-1 performs essential functions in microvessel formation and integrity and that mutant fibrillin-1-induced defects can be rescued pharmacologically.
Project description:Analysis of mouse Adamts6 and Adamts10 mutant embryos, lacking these homologous secreted metalloproteases individually and in combination, along with in vitro analysis of microfibrils, measurement of ADAMTS6-fibrillin affinities and N-terminomics determination of ADAMTS6-cleaved sites, demonstrates a transcriptionally adapted system for fibrillin-2 proteolysis that contributes to postnatal fibrillin-1 dominance. The lack of ADAMTS6, alone and in combination with ADAMTS10 led to excess fibrillin-2 in perichondrium, with impaired skeletal development. Although ADAMTS6 cleaves fibrillin-1 and fibrillin-2 as well as fibronectin, which provides the initial scaffold for microfibril assembly, primacy of the protease-substrate relationship between ADAMTS6 and fibrillin-2 was unequivocally established by reversal of these defects in Adamts6-/- embryos by genetic reduction of Fbn2, but not Fbn1.
Project description:We used microarrays to characterize the global changes in gene expression within the ascending aorta of mice due to conditional disruption of TGF-M-NM-2 signaling in smooth muscle and/or due to heterozygous fibrillin-1 mutation. Myh11-CreERT2.Tgfbr2f/f (abbreviated as Cre.Tgfbr2) mice were cross-bred to Fbn1C1039G/+ (abbreviated as Fbn1C/+) mice and treated with vehicle or tamoxifen for 5 d starting at 4 wk of age to generate 4 groups of animals: 1) Cre.Tgfbr2-Veh: controls with intact TGF-M-NM-2 signaling and wild-type fibrillin-1 expression; 2) Cre.Tgfbr2-Tmx: conditional disruption of Tgfbr2 in smooth muscle with wild-type fibrillin-1 expression; 3) Fbn1C1039G.Cre.Tgfbr2-Veh: heterozygous expression of mutant fibrillin-1 with intact TGF-M-NM-2 signaling; and 4) Fbn1C1039G.Cre.Tgfbr2-Tmx: conditional disruption of Tgfbr2 in smooth muscle with heterozygous expression of mutant fibrillin-1. The animals were euthanized at 6 weeks of age and their ascending aortas (from above the coronary arteries to the first arch branch) were collected and total RNA was extracted.
Project description:Fibrillin microfibrils are large supramolecular ECM assemblies which play different functional roles in different tissues. We aim to compare the ultrastructure and biological composition of fibrillin microfibrils purified from human eye, skin and cultured dermal fibroblasts. This will allow us to understand whether these their structure and compositions have evolved to suit the functions they play in different tissues.
Project description:Molecular analysis of circadian rhythm in mice. Liver tissue of wildtype, Clock mutant and Cry deficient C57BL/6 8- to 10-week-old male mice examined. Keywords = circadian rhythm Keywords: other