| 1. |
- Li, Yang, et al.
(författare)
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VEGF-B inhibits apoptosis via VEGFR-1-mediated suppression of the expression of BH3-only protein genes in mice and rats.
- 2008
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Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 118:3, s. 913-923
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Tidskriftsartikel (refereegranskat)abstract
- Despite its early discovery and high sequence homology to the other VEGF family members, the biological functions of VEGF-B remain poorly understood. We revealed here a novel function for VEGF-B as a potent inhibitor of apoptosis. Using gene expression profiling of mouse primary aortic smooth muscle cells, and confirming the results by real-time PCR using mouse and rat cell lines, we showed that VEGF-B inhibited the expression of genes encoding the proapoptotic BH3-only proteins and other apoptosis- and cell death-related proteins, including p53 and members of the caspase family, via activation of VEGFR-1. Consistent with this, VEGF-B treatment rescued neurons from apoptosis in the retina and brain in mouse models of ocular neurodegenerative disorders and stroke, respectively. Interestingly, VEGF-B treatment at the dose effective for neuronal survival did not cause retinal neovascularization, suggesting that VEGF-B is the first member of the VEGF family that has a potent antiapoptotic effect while lacking a general angiogenic activity. These findings indicate that VEGF-B may potentially offer a new therapeutic option for the treatment of neurodegenerative diseases.
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| 2. |
- Wagsaeter, Dick, et al.
(författare)
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Effects of PDGF-C and PDGF-D on monocyte migration and MMP-2 and MMP-9 expression
- 2009
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Ingår i: Atherosclerosis. - : Elsevier BV. - 0021-9150 .- 1879-1484. ; 202:2, s. 415-423
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Tidskriftsartikel (refereegranskat)abstract
- Background and nuns: Atherosclerosis is a chronic inflammatory process involving the activity of several cytokines and growth factors. Platelet-derived growth factor-A (PDGF-A) and PDGF-B are important mitogens and chemoattractants for monocytcs as well as smooth muscle cells. We sought to identify the role of PDGF-C and PDGF-D, two new members of the PDGF family, in monocyte migration and differentiation. We also assessed their effects in regulating matrix metalloproteinase-2 (MMP-2) and MMP-9. which are important for cell migration. Methods and results: PDGF-C and PDGF-D were expressed in macrophages, smooth muscle cells, and endothelial cells in human atherosclerotic plaques, as shown by immunohistochemical analysis. PDGF-C and PDGF-I) mRNA and protein expression was induced after differentiation of THP-1 monocytes to macrophages, and both PDGF-C and PDGF-D induced MMP-9 mRNA expression in a concentration-dependent manner. Treatment of cells with PDGF-C or PDGF-D enhanced the secretion of MMP-2 and MMP-9 in a cell-dependent manner. In a migration assay using a Boyden chamber with 8 mu m pore size, PDGF-C and PDGF-D attracted THP-1 monocytes in a concentration-dependent manner. Conclusions: Our data suggest that PDGF-C and PDGF-D, like PDGF-A and PDGF-B, play important roles in atherosclerosis by stimulating MMP activity and influencing monocyte migration.
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| 3. |
- Wågsäter, Dick, et al.
(författare)
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ADAMTS-4 and-8 are inflammatory regulated enzymes expressed in macrophage-rich areas of human atherosclerotic plaques
- 2008
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Ingår i: Atherosclerosis. - : Elsevier. - 0021-9150 .- 1879-1484. ; 196:2, s. 514-522
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES:Remodeling of extracellular matrix (ECM) plays an important role in inflammatory disorders such as atherosclerosis. ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) is a recently described family of proteinases that is able to degrade the ECM proteins aggrecan and versican expressed in blood vessels. The purpose of the present study was to analyze the expression and regulation of several ADAMTSs before and after macrophage differentiation and after stimulation with IFN-gamma, IL-1beta and TNF-alpha. ADAMTS expression was also examined during atherosclerosis development in mice and in human atherosclerotic plaques.METHODS AND RESULTS:Real time RTPCR showed that, of the nine different ADAMTS members examined, only ADAMTS-4 and -8 were induced during monocyte to macrophage differentiation, which was also seen at protein level. Macrophage expression of ADAMTS-4, -7, -8 and -9 mRNA were enhanced upon stimulation with IFN-gamma or TNF-alpha. Furthermore, immunohistochemical analyses revealed that ADAMTS-4 and -8 were expressed in macrophage rich areas of human atherosclerotic carotid plaques and coronary unstable plaques. In addition, ADAMTS-4 expression was upregulated during the development of atherosclerosis in LDLR(-/-)ApoB(100/100) mice. Whereas ADAMTS-4 expression was low in non-atherosclerotic aortas, it was significantly higher in aortas from 30-40-week old atherosclerotic animals.CONCLUSION:The present study suggests that ADAMTS-4 and -8 are inflammatory regulated enzymes expressed in macrophage-rich areas of atherosclerotic plaques. This is the first study associating ADAMTS-4 and -8 expression with atherosclerosis. However, further experiments are required to understand the physiological and pathological functions of ADAMTS in the vascular wall, and tools to measure ADAMTS activity need to be developed.
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| 4. |
- Wågsäter, Dick, et al.
(författare)
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MMP-2 and MMP-9 are prominent matrix metalloproteinases during atherosclerosis development in the LdlrApob100/100 mouse
- 2011
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Ingår i: International Journal of Molecular Medicine. - : Spandidos Publications. - 1107-3756 .- 1791-244X. ; 28:2, s. 247-253
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Tidskriftsartikel (refereegranskat)abstract
- Matrix-degrading proteases capable of degrading components of the extracellular matrix may play an important role in development and progression of atherosclerotic lesions. In the present study, we used the Ldlr(-/-)Apob(100/100) mouse model, which has a plasma lipoprotein profile similar to that of humans with atherosclerosis, to study the expression of matrix metalloproteinases (MMPs) during early stages of atherosclerosis development. We analyzed the expression of 11 proteases and three protease inhibitors in 5- to 40-week-old Ldlr(-/-)Apob(100/100) mice. Expression and activity of MMP-2 and MMP-9 was increased in advanced atherosclerotic lesions followed by macrophage infiltration as shown by real-time PCR, gel-based and in situ zymography and immunohistochemistry. Expression of other investigated MMPs did not increase during disease progression. However, the mRNA expression of MMP-8 and MMP-13 was down-regulated, which could explain the relatively high amount of collagen observed in the vessels in this model. In conclusion, low proteolytic expression at early stages of atherogenesis and a limited repertoire of proteolytic enzymes were associated with the progression of atherosclerosis in Ldlr(-/-)Apob(100/100) mice. The study suggests that MMP-2 and MMP-9 are the main proteases involved in atherogenesis in this mouse model.
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| 5. |
- Zhang, Fan, et al.
(författare)
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Proliferative and Survival Effects of PUMA Promote Angiogenesis
- 2012
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Ingår i: Cell Reports. - : Elsevier (Cell Press). - 2211-1247. ; 2:5, s. 1272-1285
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Tidskriftsartikel (refereegranskat)abstract
- The p53 upregulated modulator of apoptosis (PUMA) is known as an essential apoptosis inducer. Here, we report the seemingly paradoxical finding that PUMA is a proangiogenic factor critically required for the proliferation and survival of vascular and microglia cells. Strikingly, Puma deficiency by genetic deletion or small hairpin RNA knockdown inhibited developmental and pathological angiogenesis and reduced microglia numbers in vivo, whereas Puma gene delivery increased angiogenesis and cell survival. Mechanistically, we revealed that PUMA plays a critical role in regulating autophagy by modulating Erk activation and intracellular calcium level. Our findings revealed an unexpected function of PUMA in promoting angiogenesis and warrant more careful investigations into the therapeutic potential of PUMA in treating cancer and degenerative diseases.
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| 6. |
- Zhu, Chaoyong, et al.
(författare)
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Allele-specific MMP-3 transcription under in vivo conditions
- 2006
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 348:3, s. 1150-1156
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Tidskriftsartikel (refereegranskat)abstract
- A common matrix metalloproteinases-3 (MMP-3) -1612 5A/6A promoter polymorphism is associated with risk for cardiovascular disease, rheumatoid arthritis, and other diseases. Here we used the haplotype chromatin immunoprecipitation method to study allele-specific MMP-3 expression under in vivo conditions in heterozygous THP-1 cells. Pyrosequencing was used to analyse the ratio of 5A-allele to 6A-allele after chromatin immunoprecipitation using an antibody against phosphorylated active RNA polymerase II. There was no allele-specific difference in transcriptional activity during basal conditions, i.e., in unstimulated monocytic THP-1 cells. However, after stimulation of MMP-3 expression by monocyte differentiation or incubation with IL-1 beta, the haplotype containing the 5A-allete was associated with higher transcriptional activity compared with the 6A-containing haplotype. Electromobility shift assay demonstrated increased binding of nuclear proteins to the 5A-allele after monocyte differentiation. In conclusion, the common MMP-3 5A/6A promoter polymorphism appears to be functional only during specific environmental conditions involving inflammation.
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| 7. |
- Zhu, Chaoyong
(författare)
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Deoxyribonucleoside kinases in nuclear and mitochondrial DNA precursor synthesis : phosphorylation of anti-cancer nucleoside analogs in different subcellular compartments
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Nucleoside analogs have been developed as anticancer and antiviral agents. The main mechanism of action of nucleoside analogs is the incorporation of the corresponding analog triphosphate into DNA where it interferes with DNA replication. The phosphorylation to the triphosphate form by cellular or viral enzymes is therefore required for the activation of nucleoside analogs. The first step of phosphorylation, catalyzed by nucleoside kinases, is regarded as being rate-limiting for most nucleoside analogs. DNA replication occurs both in the nucleus and in the mitochondria. Thus, both nuclear and mitochondrial DNA can be targeted by nucleoside analogs. My research mainly addresses questions regarding nucleoside analog phosphorylation in the mitochondria. First, one of the mitochondrial deoxyribonucleoside kinases, deoxyguanosine kinase (dGK), was characterized with regard to its kinetic properties for natural substrates as well as for clinically important nucleoside analogs. We showed that dGK could efficiently phosphorylate the nucleoside analogs araG, CdA and dFdG. Overexpression of dGK in the mitochondria of pancreatic cancer cell lines enhanced the sensitivity to dGK phosphorylated nucleoside analogs. These data suggested that this mitochondrial dcoxyribonucleoside kinase plays a role for nucleoside analog phosphorylation. Furthermore, we created a cell model by targeting genetically engineered dCK to the different subcellular compartments of a dCK deficient cell line. The expression of dCK in the nucleus, the cytosol or the mitochondria restored the sensitivity to dCK phosphorylated nucleoside analogs. By using autoradiography, we showed that nucleoside analogs phosphorylated by dCK in the mitochondria were predominantly incorporated into mitochondrial DNA, while nucleoside analogs phosphorylated in the nucleus or cytosol were incorporated into nuclear DNA. We concluded that incorporation of nucleoside analogs into nuclear or mitochondrial DNA was determined by the intracellular phosphorylation site. We also showed that nucleoside analogs phosphorylated in the mitochondria could initiate apoptosis similar to nucleoside analogs phosphorylated in the nucleus or the cytosol. The same cell model was used to study the cytotoxicity of nucleoside analogs in combination with the ribonucleotide reductase inhibitor hydroxyurea. The results showed that the combination of nucleoside analogs and hydroxyurea resulted in synergistic effects when the nucleoside analogs were phosphorylated in the nucleus or the cytosol but not when phosphorylated in the mitochondria. We have also shown by autoradiography that araG was predominantly incorporated into mitochondrial DNA while araC was incorporated into nuclear DNA. This finding may contribute to explain the selective cytotoxicity of araG in T-lymphocytes. In summary, our results showed that mitochondrial kinases play a role for micleoside analog activation. We believe that our findings are important in the development of improved therapeutic strategies involving nucleoside analogs.
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