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O4–06–01: Docosahexaenoic acid stabilizes soluble amyloid–β protofibrils and sustains amyloid–β induced neurotoxicity In vitro
Author(s) -
Johansson Ann-Sofi,
Garlind Anita,
Berglind-Dehlin Fredrik,
Gellerfors Pär,
Ekholm-Pettersson Frida,
Palmblad Jan,
Lannfelt Lars
Publication year - 2006
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2006.05.336
Subject(s) - arachidic acid , docosahexaenoic acid , polyunsaturated fatty acid , chemistry , arachidonic acid , neurotoxicity , biochemistry , fatty acid , fibril , in vitro , amyloid (mycology) , toxicity , palmitic acid , organic chemistry , inorganic chemistry , enzyme
ronal development. Methods: We used the powerful method of in utero electroporation of DNA constructs into the developing rodent cortex to either knock down or over-express APP, its proteolytic derivatives, and certain binding partners. In our studies, DNA constructs are injected into one of the lateral ventricles of the embryonic rodent brain, and electroporated into a subset of cells in the cortical ventricular zone. DNA constructs encoding GFP are co-electroporated to follow transfected cells. Postsurgery, embryos develop normally in utero. We examine the effects of APP knock down at 3612and 30-days post electroporation. Results: In utero electroporation of APP shRNA constructs led to the generation of mosaic regions of developing cortex in which APP expressing and nonexpressing cells neighbor one another. Qualitative and quantitative analyses revealed that neuronal precursors in the cortex require APP to migrate correctly into the cortical plate. Cells that received GFP and an inactive APP shRNA migrated properly through the intermediate zone and into the cortical plate, whereas the majority of cells that received active APP shRNA were retarded in the intermediate zone, where they prematurely differentiated into neurons. The minority of cells expressing active shRNA that migrated into the cortical plate did not migrate to the correct layer and displayed abnormal neurite outgrowth. Co-electroporation of holoAPP cDNA substantially rescued the shRNA-mediated migration defect. Various proteolytic derivatives of APP as well as APLP-1 and -2 are being tested for their rescue abilities, to address the mechanism by which APP performs this function. We conclude that acute knock-down of APP in utero reveals a required function for the precursor in cortical cell migration during development.