Project description:We report dynamic temporal and spatial smooth muscle cell phenotype modulation using aortic single cell RNA sequencing in a murine model of Marfan syndrome (Fbn1C1041G/+) and littermate controls. Aortic root/ascending aortic tissue samples from both genotypes were studied at 4 and 24 weeks of age. The non-aneurysmal descending thoracic aorta was also studied at 24 weeks. Finally human aortic tissue from a Marfan syndrome patient undergoing aneurysm repair surgery was studied.
Project description:Using Cdh5-Cre and Sm22-Cre transgenes to characterize the impact of disruption of the angiotensin II type 1a receptor (AT1ar) in vascular endothelial and smooth muscle cells, respectively, of wild type (WT) mice compared to fibrillin-1 hypomorphic mice (Fbn1mgR/mgR mice) that replicate early onset progressively severe Marfan syndrome (MFS) with dissecting thoracic aortic aneurysm (TAA).
Project description:We analyzed differentially expressed genes in smooth muscle cells derived from the thoracic aorta of Marfan Syndrome (MFS) patients and control subjects to identify cell biological mechanisms contributing to thoracic aoritc aneurysm (TAA) development and rupture. These mechanisms were used to identify a potential drug treatment to mitigate TAA progression. We analyzed differentially expressed genes in whole aorta of P16 MFS mice vs WT mice to identify cell biological mechanisms contributing to thoracic aoritc aneurysm (TAA) development and rupture. These mechanisms were used to identify baclofen as a potential drug treatment to mitigate TAA progression. The effect of baclofen on gene expression in WT and MFS was documented in P60 mice that received treatment since P16.
Project description:To improve our limited understanding of the pathogenesis of thoracic aortic aneurysm (TAA) leading to acute aortic dissection, we used single-cell RNA sequencing to profile disease-relevant transcriptomic changes of aortic cell populations in a well-characterized mouse model of the most commonly diagnosed form of Marfan syndrome (MFS). As result,MFSmod were identified only in the aorta of Fbn1mgR/mgR mice. In situ hybridizations of diagnostic transcripts located MFSmod cells to the intima of Fbn1mgR/mgR aortas. Consistent with angiotensin II type I receptor (At1r) contribution to TAA development, MFSmod cells were absent in the aorta of Fbn1mgR/mgR mice treated with the At1r antagonist losartan. Altogether, our findings indicate that a discrete dynamic alteration of aortic cell identity is associated with dissecting TAA in MFS mice and increased risk of aortic dissection in MFS patients.
Project description:The goal of this study is to define the main tissue and mechanism implicated in the long bone overgrowth phenotype in mice with Marfan syndrome
Project description:Background: Marfan syndrome (MFS) is a heritable connective tissue disorder caused by mutations in the fibrillin-1 gene. This syndrome constitutes a significant identifiable subtype of aortic aneurysmal disease, accounting for over 5% of ascending and thoracic aortic aneurysms. Results: We used spotted membrane DNA macroarrays to identify genes whose altered expression levels may contribute to the phenotype of the disease. Our analysis of 4132 genes identified a subset with significant expression differences between skin fibroblast cultures from unaffected controls versus cultures from affected individuals with known fibrillin-1 mutations. Subsequently, 10 genes were chosen for validation by quantitative RT-PCR. Conclusions: Differential expression of many of the validated genes was associated with MFS samples when an additional group of unaffected and MFS affected subjects were analyzed (p-value < 3 x 10-6 under the null hypothesis that expression levels in cultured fibroblasts are unaffected by MFS status). An unexpected observation was the range of individual gene expression. In unaffected control subjects, expression ranges exceeding 10 fold were seen in many of the genes selected for qRT-PCR validation. The variation in expression in the MFS affected subjects was even greater. Keywords: disease state comparison; Marfan syndrome; cultured skin fibroblasts
Project description:Aortic smooth muscle cell (SMC) phenotype modulation is a central feature of cell-mediated pathology in Marfan syndrome aortic aneurysm and Klf4 is proposed to contribute to this process. We generated mice with smooth muscle cell-specific Klf4 deletion using an Myh11-creERT2 transgene, induced deletion at 8 weeks and performed single cell RNA sequencing at 24 weeks on whole aortic root tissues.
