RESUMO
Alzheimer's disease (AD) is the most common proteinopathy, which is accompanied by a steady decrease in the patient's cognitive functions with a simultaneous accumulation of amyloid plaques in brain tissues. Amyloid plaques are extracellular aggregates of amyloid ß (Aß) and are associated with neuroinflammation and neurodegeneration. Unlike humans and all other mammals, rats and mice do not reproduce AD-like pathology because there are three amino acid substitutions in their Aß. Amyloid plaques form in the brains of transgenic mice with overexpression of human Aß, and such mice are therefore possible to use in biomedicine to model the key features of AD. The transgenic mouse line APPswe/PS1dE9 is widely used as an animal model to study the molecular mechanisms of AD. A study was made to characterize the APPswe/PS1dE9/Blg subline, which was obtained by crossing APPswe/PS1dE9 mice on a CH3 genetic background with C57Bl6/Chg mice. No difference in offspring's survival and fertility was observed in the subline compared to wild-type control mice. Histological analysis of the brain in the APPswe/PS1dE9/Blg line confirmed the main neuromorphological features of AD and showed that amyloid plaques progressively increase in number and size during aging. The APPswe/PS1dE9/Blg line was assumed to provide a convenient model for developing therapeutic strategies to slow down AD progression.
Assuntos
Doença de Alzheimer , Angiopatia Amiloide Cerebral , Camundongos , Humanos , Ratos , Animais , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Camundongos Transgênicos , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Placa Amiloide/genética , Angiopatia Amiloide Cerebral/genética , Angiopatia Amiloide Cerebral/complicações , Angiopatia Amiloide Cerebral/metabolismo , Encéfalo/metabolismo , Modelos Animais de Doenças , MamíferosRESUMO
Aggregated forms of α-synuclein are core components of pathohistological inclusions known as Lewy bodies in substantia nigra (SN) neurons of patients with Parkinson's disease (PD). The role of α-synuclein in selective loss of SN dopaminergic neurons (DNs) in PD is studied in mice knocked out in the α-synuclein gene. The new mouse strain delta flox KO with a constitutive knockout of the α-synuclein gene models the end point of in vivo deletion of the α-synuclein gene in mice with a conditional knockout and has no foreign sequence in the modified genomic locus, thus differing from all other α-synuclein knockout mouse strains. The effect of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which is used to model PD, was compared between delta flox KO mice and mice of the well-known α-synuclein knockout strain AbKO. Subchronic MPTP administration, which models early PD, was found to reduce the dopamine content and to change the ratio of dopamine metabolites in the striatum to the same levels in delta flox KO, ÐbKO, and wild-type mice. Overt locomotor defects were not observed after MPTP treatment, but gait testing in a CatWalk XT (Noldus) system revealed identical gait deviations in mice of the two strains and control wild-type mice. Based on the findings, a similar mechanism of neurotoxic damage to DNs was assumed for delta flox KO and AbKO mice.
Assuntos
Intoxicação por MPTP , alfa-Sinucleína , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Animais , Modelos Animais de Doenças , Neurônios Dopaminérgicos/metabolismo , Humanos , Intoxicação por MPTP/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Substância Negra/metabolismo , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismoRESUMO
Multimerin-1 (Mmrn-1) is a soluble protein, also known as elastin microfibril interfacer 4 (EMILIN-4), found in platelets and in the endothelium of blood vessels. Its function and role in pathology are still not fully understood. Genetic modifications in alpha-synuclein gene (Snca) locus that mapped 160 Kb apart from Mmrn-1 in mouse genome, could weigh with regulatory elements of Mmrn-1 gene. We have studied the Mmrn-1 expression in brain cortex of three mouse lines with Snca knock-out: B6(Cg)-Sncatm1.2Vlb/J, B6;129-Sncatm1Sud/J, and B6;129X1-Sncatm1Rosl/J. The 35-fold increase for Mmrn-1 mRNA level have been found in B6;129X1-Sncatm1Rosl/J mice that carry in their genome foreign sequences including bacterial gene neo and a strong promoter of a mouse phosphoglycerate kinase (Pgk1) oriented towards Mmrn-1 gene. This effect on regulatory elements of Mmrn-1 gene as a result of modifications in Snca locus should be taken into consideration when using B6;129X1-Sncatm1Rosl/J line, that is widely applied for study of neurodegeneration mechanisms.
Assuntos
Proteínas Sanguíneas/genética , Encéfalo/metabolismo , Moléculas de Adesão Celular/genética , alfa-Sinucleína/genética , Animais , Regulação da Expressão Gênica/genética , Camundongos , Camundongos KnockoutRESUMO
In the present study, we analyzed the uptake of radiolabeled dopamine by intact synaptosomes and purified synaptic vesicles isolated from the dorsal striatum of mice with constitutive inactivation of all three synuclein-coding genes and wild-type mice. Synuclein deficiency substantially compromised the uptake of this neurotransmitter by synaptic vesicles but had no effect on synaptosomal dopamine uptake.
