RESUMO
Recessively inherited loss-of-function mutations in the PTEN-induced putative kinase 1(Pink1), DJ-1 (Park7) and Parkin (Park2) genes are linked to familial cases of early-onset Parkinson's disease (PD). As part of its strategy to provide more tools for the research community, The Michael J. Fox Foundation for Parkinson's Research (MJFF) funded the generation of novel rat models with targeted disruption ofPink1, DJ-1 or Parkin genes and determined if the loss of these proteins would result in a progressive PD-like phenotype. Pathological, neurochemical and behavioral outcome measures were collected at 4, 6 and 8months of age in homozygous KO rats and compared to wild-type (WT) rats. Both Pink1 and DJ-1 KO rats showed progressive nigral neurodegeneration with about 50% dopaminergic cell loss observed at 8 months of age. ThePink1 KO and DJ-1 KO rats also showed a two to three fold increase in striatal dopamine and serotonin content at 8 months of age. Both Pink1 KO and DJ-1 KO rats exhibited significant motor deficits starting at 4months of age. However, Parkin KO rats displayed normal behaviors with no neurochemical or pathological changes. These results demonstrate that inactivation of the Pink1 or DJ-1 genes in the rat produces progressive neurodegeneration and early behavioral deficits, suggesting that these recessive genes may be essential for the survival of dopaminergic neurons in the substantia nigra (SN). These MJFF-generated novel rat models will assist the research community to elucidate the mechanisms by which these recessive genes produce PD pathology and potentially aid in therapeutic development.
Assuntos
Proteínas Associadas aos Microtúbulos/deficiência , Transtornos Parkinsonianos/fisiopatologia , Fenótipo , Proteínas Quinases/deficiência , Ubiquitina-Proteína Ligases/deficiência , Envelhecimento , Animais , Animais Geneticamente Modificados , Encéfalo/patologia , Encéfalo/fisiopatologia , Dopamina/metabolismo , Neurônios Dopaminérgicos/patologia , Neurônios Dopaminérgicos/fisiologia , Técnicas de Inativação de Genes , Genes Recessivos , Masculino , Proteínas Associadas aos Microtúbulos/genética , Atividade Motora/fisiologia , Transtornos Parkinsonianos/genética , Transtornos Parkinsonianos/patologia , Proteína Desglicase DJ-1 , Proteínas Quinases/genética , Ratos Long-Evans , Serotonina/metabolismo , Ubiquitina-Proteína Ligases/genéticaRESUMO
A method for improving separations of peptides and other positively charged species in capillary zone electrophoresis with untreated capillaries using acidic buffers containing tetraalkylammonium cations is described. Tetramethylammonium and tetrabutylammonium cations dynamically modify the capillary surface, leading to a reversal in the direction of the electroosmotic flow. As a result, the adsorption of positively charged peptides and proteins is minimized, and resolution and peak capacity are improved as the migration of cationic analytes is counterbalanced by the electroosmotic flow. The combining effect of reversing electroosmotic flow and cyclodextrin inclusion complexation on separations of closely related peptides and a protein mixture, as well as tryptic digest of hemoglobin is demonstrated.