| 1. |
- Hansson, Oskar, et al.
(författare)
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Overexpression of heat shock protein 70 in R6/2 Huntington's disease mice has only modest effects on disease progression.
- 2003
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Ingår i: Brain Research. - 1872-6240. ; 970:1-2, s. 47-57
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Tidskriftsartikel (refereegranskat)abstract
- Huntington’s disease (HD) is a neurodegenerative disorder caused by expansion of a polyglutamine tract in a protein called huntingtin. The inducible form of heat shock protein 70 (Hsp70) has been shown to reduce polyglutamine-induced toxicity. To investigate if overexpression of Hsp70 can affect disease progression in a mouse model of HD, we crossed R6/2 mice, expressing exon 1 of the HD gene with an expanded CAG repeat, with mice overexpressing Hsp70 (both types of transgenic mice were of the CBAxC57BL/6 strain). The resulting R6/2-Hsp70 transgenics exhibited 5- to 15-fold increases in Hsp70 expression in neocortical, hippocampal and basal ganglia regions. This correlated with a delayed loss of body weight compared to R6/2 mice. However, the number or size of nuclear inclusions, the loss of brain weight, reduction of striatal volume, reduction in size of striatal projection neurons, downregulation of DARPP-32, development of paw clasping phenotype and early death of the mice were not affected by Hsp70 overexpression. Interestingly, the polyglutamine protein affected the potential rescuing agent, because in older R6/2-Hsp70 mice a large proportion of the Hsp70 protein was sequestrated in nuclear inclusions.
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| 2. |
- Moreno-Pescador, Guillermo, et al.
(författare)
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Curvature- and Phase-Induced Protein Sorting Quantified in Transfected Cell-Derived Giant Vesicles
- 2019
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 13:6, s. 6689-6701
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Tidskriftsartikel (refereegranskat)abstract
- Eukaryotic cells possess a dynamic network of membranes that vary in lipid composition. To perform numerous biological functions, cells modulate their shape and the lateral organization of proteins associated with membranes. The modulation is generally facilitated by physical cues that recruit proteins to specific regions of the membrane. Analyzing these cues is difficult due to the complexity of the membrane conformations that exist in cells. Here, we examine how different types of membrane proteins respond to changes in curvature and to lipid phases found in the plasma membrane. By using giant plasma membrane vesicles derived from transfected cells, the proteins were positioned in the correct orientation and the analysis was performed in plasma membranes with a biological composition. Nanoscale membrane curvatures were generated by extracting nanotubes from these vesicles with an optical trap. The viral membrane protein neuraminidase was not sensitive to curvature, but it did exhibit strong partitioning (coefficient of K = 0.16) disordered membrane regions. In contrast, the membrane repair protein annexin 5 showed a preference for nanotubes with a density up to 10-15 times higher than that on the more flat vesicle membrane. The investigation of nanoscale effects in isolated plasma membranes provides a quantitative platform for studying peripheral and integral membrane proteins in their natural environment.
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| 3. |
- Olsson, Tomas, et al.
(författare)
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Lack of neuroprotection by heat shock protein 70 overexpression in a mouse model of global cerebral ischemia.
- 2004
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Ingår i: Experimental Brain Research. - : Springer Science and Business Media LLC. - 0014-4819 .- 1432-1106. ; 154:4, s. 442-449
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Tidskriftsartikel (refereegranskat)abstract
- Heat shock protein 70 (Hsp70) is induced in cells by a variety of stress conditions, is known to be cytoprotective, and has been proposed to be neuroprotective during brain ischemia. A recently developed mouse model of 12-min global cerebral ischemia by bilateral common carotid artery occlusion with artificial ventilation and bilateral monitoring of regional cerebral blood flow by laser Doppler was applied. We examined the expression and possible neuroprotective role of the inducible form of Hsp70 in the mouse brain following global cerebral ischemia. Ischemia induced a marked expression of Hsp70 in the ischemia vulnerable CA1-CA3 region of the hippocampus. Intraischemic hypothermia (33degreesC) prevented cell damage without noticeable expression of Hsp70. A transgenic mouse overexpressing Hsp70 was subjected to 12 min of global cerebral ischemia, and the brain damage was evaluated after 4 days. No neuroprotection of ischemia-induced brain damage in hippocampus, striatum, cortex or thalamus was found in Hsp70 transgenic animals compared with wild-type littermate mice. We suggest that overexpression of Hsp70 following cerebral ischemia is an indicator of cell stress. Also, constitutively overexpression of Hsp70 is insufficient to effectively influence cell death after global cerebral ischemia in the mouse.
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