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- Reynolds, Regina Hertfelder, et al.
(författare)
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Perturbations in the p53/miR-34a/SIRT1 pathway in the R6/2 Huntington's disease model
- 2018
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Ingår i: Molecular and Cellular Neuroscience. - : Elsevier BV. - 1044-7431. ; 88, s. 118-129
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Tidskriftsartikel (refereegranskat)abstract
- The three factors, p53, the microRNA-34 family and Sirtuin 1 (SIRT1), interact in a positive feedback loop involved in cell cycle progression, cellular senescence and apoptosis. Each factor in this triad has roles in metabolic regulation, maintenance of mitochondrial function, and regulation of brain-derived neurotrophic factor (BDNF). Thus, this regulatory network holds potential importance for the pathophysiology of Huntington's disease (HD), an inherited neurodegenerative disorder in which both mitochondrial dysfunction and impaired neurotrophic signalling are observed. We investigated expression of the three members of this regulatory triad in the R6/2 HD mouse model. Compared to wild-type littermates, we found decreased levels of miR-34a-5p, increased SIRT1 mRNA and protein levels, and increased levels of p53 protein in brain tissue from R6/2 mice. The upregulation of SIRT1 did not appear to lead to an increased activity of the enzyme, as based on measures of p53 acetylation. In other words, the observed changes did not reflect the known interactions between these factors, indicating a general perturbation of the p53, miR-34a and SIRT1 pathway in HD. This is the first study investigating the entire triad during disease progression in an HD model. Given the importance of these three factors alone and within the triad, our results indicate that outside factors are regulating – or dysregulating – this pathway in HD.
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| 2. |
- Tolstrup Nielsen, Troels, et al.
(författare)
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Neuron-specific RNA interference using lentiviral vectors
- 2009
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Ingår i: Journal of Gene Medicine. - : Wiley. - 1521-2254 .- 1099-498X. ; 11:7, s. 559-569
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Tidskriftsartikel (refereegranskat)abstract
- Background Viral vectors have been used in several different settings for the delivery of small hairpin (sh) RNAs. However, most vectors have utilized ubiquitously-expressing polymerase (pol) III promoters to drive expression of the hairpin as a result Of the Strict requirement for precise transcriptional initiation and termination. Recently, pol 11 promoters have been used to construct vectors for RNA interference (RNAi). By embedding the shRNA into a micro RNA-context (miRNA) the endogenous miRNA processing machinery is exploited to achieve the mature synthetic miRNA (smiRNA), thereby expanding the possible promoter choices and eventually allowing cell type specific down-regulation of target genes. Methods In the present study, we constructed lentiviral vectors expressing smiRNAs under the control of pol II promoters to knockdown gene expression in cell Culture and in the brain. Results We demonstrate robust kockdown of green fluorescent protein using lentiviral vectors driving RNAi from the ubiquitously-expressing promoter of the cytomegalovirus (CMV) and, in addition, we show for the first time neuron-specific knockdown in the brain using a neuron-specific promoter. Furthermore, we show that the expression pattern of the presumed ubiquitously-expressing CMV promoter changes over time from being expressed initially in neurons and glial cells to being expressed almost exclusively in neurons in later stages. Conclusions In the present study, we developed vectors for cell-specific RNAi for use in the brain. This offers the possibility of specifically targeting RNAi to a subset of cells in a complex tissue and may prove to be of great importance in the design of future gene therapeutic paradigms. Copyright (C) 2009 John Wiley & Sons, Ltd.
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