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.
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:Recent studies show that hyperactivation of mTOR signaling plays a causal role in the development of thoracic aortic aneurysm (TAA) and dissection (AAD). Modulation of Protein phosphatase 2A (PP2A) activity has been shown to be of significant therapeutic value. In light of the effects that PP2A can exert on mTOR pathway, we hypothesized that PP2A activation by small molecule activators of PP2A (SMAPs) could mitigate AA progression in Marfan Syndrome (MFS).
Project description:Thoracic aortic aneurysm (TAA) is a perilous disease that can lead to aortic dissection (AD), the pathophysiological mechanisms of which remain largely elusive. To improve our understanding of the molecular mechanism underlying TAA, we conducted a tandem mass tag (TMT)-based proteomics analysis and identified two down-regulated proteins, integrin αV, and integrin αL, in serum samples from patients with type A aortic dissection. We confirmed that integrin αV is extensively expressed in the aortic media, and its expression decreases after dissection, whereas the expression of integrin αL showed no significant alteration. Subsequently, by employing a mouse model of TAA induced by β-Aminopropionitrile (BAPN), we discovered that the mice treated with integrin αV inhibitors Cilengitide or SB273005 developed dramatically expansive ascending TAA, accompanied by exacerbated disorganization or loss of elastic fibers. Bulk RNA sequencing results further indicated that the treatment with integrin αV inhibitors exacerbates the pro-inflammatory response in mouse TAA development. These data suggest that integrin αV may be a novel target for TAA intervention. However, it also raises concerns about exposure to integrin αV inhibitors, which are conducted in serious cancer clinical trials, may pose a potential risk of developing aortic aneurysm (AA)/AD.
Project description:Although abnormal TGFbeta signaling is observed in several heritable forms of thoracic aortic aneurysms and dissections including Marfan syndrome, the precise role of TGFbeta signaling in aortic disease progression is still disputed. Using a mouse genetic approach and quantitative isobaric labeling proteomics, we sought to investigate the role of TGFbeta signaling in molecular pathways of pathogenesis associated with development of aortic aneurysm and aortic rupture. This study reports an isoform-specific effect of TGFbeta in MFS aortic disease and the effects of deleting the first hybrid domain of fibrillin-1 on TGFbeta signaling. Distinct molecular differences in mouse models of aneurysm (Fbn_GT-8_plus), of aneurysm and rupture (Fbn1_GT-8_H1delta), and of microdissection (Fbn1_H1delta_plus) were identified, which associated with TGFbeta signaling and extracellular matrix composition, possibly contributing to the development of dissection and rupture. These findings offer new insights into the pathophysiological mechanisms that potentially drive initiation of aortic dissection and could pave the way for development of new treatment targets of aortic disease.
Project description:Thoracic aortic aneurysm (TAA) is a perilous disease that can lead to aortic dissection (AD), the pathophysiological mechanisms of which remain largely elusive. To improve our understanding of the molecular mechanism underlying TAA, we conducted a tandem mass tag (TMT)-based proteomics analysis and identified two down-regulated proteins, integrin αV, and integrin αL, in serum samples from patients with type A aortic dissection. We confirmed that integrin αV is extensively expressed in the aortic media, and its expression decreases after dissection, whereas the expression of integrin αL showed no significant alteration. Subsequently, by employing a mouse model of TAA induced by β-Aminopropionitrile (BAPN), we discovered that the mice treated with integrin αV inhibitors Cilengitide or SB273005 developed dramatically expansive ascending TAA, accompanied by exacerbated disorganization or loss of elastic fibers. Bulk RNA sequencing results further indicated that the treatment with integrin αV inhibitors exacerbates the pro-inflammatory response in mouse TAA development. These data suggest that integrin αV may be a novel target for TAA intervention. However, it also raises concerns about exposure to integrin αV inhibitors, which are conducted in serious cancer clinical trials, may pose a potential risk of developing aortic aneurysm (AA)/AD.
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:Thoracic aortic aneurysms have a higher prevalence in male patients compared to female patients. Marfan syndrome causes a hereditary form of TAA with dilation of the aortic root. Male patients with Marfan syndrome are more likely than women to have aortic dilation and dissection and mouse models of Marfan syndrome demonstrate larger aortic roots in males compared to females even after adjustment for body size. Similar sex disparities are present in patients and models of abdominal aortic aneurysms where estrogen has been demonstrated to attenuate aneurysm formation perhaps through anti-inflammatory mechanisms. In this study we demonstrate the effects of estrogen on aortic dilation and rupture in a Marfan mouse model and we investigate if these effects operate through suppression of complement components of the immune system.