| 1. |
- Rauch, Uwe, et al.
(författare)
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Increased Neointimal Thickening in Dystrophin-Deficient mdx Mice.
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The dystrophin gene, which is mutated in Duchenne muscular dystrophy (DMD), encodes a large cytoskeletal protein present in muscle fibers. While dystrophin in skeletal muscle has been extensively studied, the function of dystrophin in vascular smooth muscle is less clear. Here, we have analyzed the role of dystrophin in injury-induced arterial neointima formation. METHODOLOGY/PRINCIPAL FINDINGS: We detected a down-regulation of dystrophin, dystroglycan and β-sarcoglycan mRNA expression when vascular smooth muscle cells de-differentiate in vitro. To further mimic development of intimal lesions, we performed a collar-induced injury of the carotid artery in the mdx mouse, a model for DMD. As compared with control mice, mdx mice develop larger lesions with increased numbers of proliferating cells. In vitro experiments demonstrate increased migration of vascular smooth muscle cells from mdx mice whereas the rate of proliferation was similar in cells isolated from wild-type and mdx mice. CONCLUSIONS/SIGNIFICANCE: These results show that dystrophin deficiency stimulates neointima formation and suggest that expression of dystrophin in vascular smooth muscle cells may protect the artery wall against injury-induced intimal thickening.
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| 2. |
- Shami, Annelie, et al.
(författare)
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Collagen and related extracellular matrix proteins in atherosclerotic plaque development.
- 2014
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Ingår i: Current Opinion in Lipidology. - 1473-6535. ; 25:5, s. 394-399
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Forskningsöversikt (refereegranskat)abstract
- The structure, composition and turnover of the extracellular matrix (ECM) as well as cell-matrix interactions are crucial in the developing atherosclerotic plaque. There is a need for further insight into specific proteins in the ECM and their functions in the developing plaque, and during the last few years a number of publications have highlighted this very important field of research. These novel findings will be addressed in the present review.
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| 3. |
- Shami, Annelie
(författare)
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Fibromodulin and Dystrophin in Atherosclerosis: Novel roles for extracellular matrix in plaque development
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cardiovascular disease represents nearly half the cases of noncommunicable diseases worldwide and is the leading global cause of death. The main underlying cause is atherosclerosis, and in atherosclerotic plaque progression the structure, composition and integrity of a dynamic extracellular matrix (ECM) is one very important factor. This thesis discusses the importance of the connection between the ECM and cells for atherosclerotic lesion development. It also tests the hypothesis that changes in this connection – whether through a modified collagenous ECM, or modification in a cellular protein directly linking cells to ECM components – have a significant impact on atherosclerotic plaque structure and stability. Fibromodulin is a small leucine-rich repeat proteoglycan of the ECM involved in the regulation of collagen fiber synthesis. In the fibrous murine atherosclerotic plaque, we found collagen fibrils synthesized in the absence of fibromodulin to be thicker and more heterogeneous, compared to fibrils generated in the control mouse. Murine plaques with an inflammatory phenotype, with a fibromodulin-deficient ECM, were also smaller with decreased lipid accumulation, whereas cell proliferation was increased. In addition, we show, for the first time, that high fibromodulin expression in the most stenotic region of a human carotid artery plaque is found in plaques from symptomatic patients, and in patients with diabetes. Fibromodulin expressed in human plaques co-localize with Oil Red O-staining and correlates with the area stained for lipids (quantified as percentage). Fibromodulin also correlates with the pro-inflammatory cytokines MIP-1β and sCD40L, as well as with VEGF and inversely with the anti-inflammatory cytokine IL-10. Dystrophin, and the dystrophin-glycoprotein complex (DGC), link the actin cytoskeleton to the basement membrane. This thesis provides novel data on dystrophin deficiency, as illustrated by the mdx mouse. The absence of dystrophin stimulates neointimal hyperplasia, but inhibits atherosclerotic lesion development driven by lipid-retention. In the mdx-mouse, laminin expression is decreased in the endothelium of atherosclerotic lesions with an inflammatory phenotype, suggesting that altered endothelial cell function and an abnormal basement membrane may be a possible explanation for the attenuated plaque development. In summary, this thesis shows that collagen structure and remodeling affects the growth, development and composition of atherosclerotic lesions, on the one hand promoting mechanical stability, and on the other hand affecting lipid accumulation and inflammation. In addition, growth of vascular lesions can be inhibited or promoted by a functional connection between cells and the ECM mediated by dystrophin and the DGC.
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| 4. |
- Shami, Annelie, et al.
(författare)
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Fibromodulin Deficiency Reduces Low-Density Lipoprotein Accumulation in Atherosclerotic Plaques in Apolipoprotein E-Null Mice.
- 2012
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Ingår i: Arteriosclerosis, Thrombosis and Vascular Biology. - 1524-4636.
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim of this study was to analyze how an altered collagen structure affects development of atherosclerotic plaques. METHODS AND RESULTS: Fibromodulin-null mice develop an abnormal collagen fibril structure. In apolipoprotein E (ApoE)-null and ApoE/fibromodulin-null mice, a shear stress-modifying carotid artery cast induced formation of atherosclerotic plaques of different phenotypes; inflammatory in low-shear stress regions and fibrous in oscillatory shear stress regions. Electron microscopy showed that collagen fibrils were thicker and more heterogeneous in oscillatory shear stress lesions from ApoE/fibromodulin-null mice. Low-shear stress lesions were smaller in ApoE/fibromodulin-null mice and contained less lipids. Total plaque burden in aortas stained en face with Oil Red O, as well as lipid accumulation in aortic root lesions, was also decreased in ApoE/fibromodulin-null mice. In addition, lipid accumulation in RAW264.7 macrophages cultured on fibromodulin-deficient extracellular matrix was decreased, whereas levels of interleukin-6 and -10 were increased. Our results show that an abnormal plaque collagen fibril structure can influence atherosclerotic plaque development. CONCLUSIONS: The present findings suggest a more complex role for collagen in plaque stability than previously anticipated, in that it may promote lipid-accumulation and inflammation at the same time as it provides mechanical stability.
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