Evaluation of a-beta scavengers expression in rat choroid plexus: effects of circadian rhythm and a-beta levels

• Autor(a) principal: Hrynchak, Mariya
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.6/6062
• topic: Apolipoproteína J; Enzima Conversora de Angiotensina; Enzima de Degradação de Insulina; Gelsolina; Metalotioneína 2; Plexo Coróide; Ritmo Circadiano; ß Amiloide; Transtirretina; Domínio/Área Científica::Ciências Médicas::Ciências Biomédicas

The choroid plexus, a highly specialized tissue, is involved in a variety of functions such as production and secretion of the cerebrospinal fluid, synthesis and secretion of several bioactive substances and constituting the blood-cerebrospinal fluid barrier. Among others, the choroid plexus has the ability to produce molecules involved in the metabolism/clearance of amyloid ß peptide such as transthyretin, gelsolin, apolipoprotein J, metallothionein 2, angiotensin-converting enzyme and insulin-degrading enzyme. Some of these amyloid ß scavengers prevent the formation and deposition of amyloid fibrils. The circadian clock, present in all mammal tissues, is synchronized by zeitgebers (e.g., light/dark) over a period of approximately 24 h. In mammals, the brain is involved in the control and coordination of the circadian rhythm, which in turn, is generated by the suprachiasmatic nucleus. Peripheral and extra-suprachiasmatic nucleus clocks exist in other brain areas which are under the control of the suprachiasmatic nucleus. Among these, stands out the choroid plexus by expressing the core clock genes that show a rhythmic expression in both females and males. The aim of this project is to analyse whether the amyloid ß scavengers are influenced by circadian rhythmicity in both sexes in rat choroid plexus explants by Real-time PCR. Moreover, it was also investigated if the expression of these genes/proteins undergoes changes using different concentrations of amyloid ß (1 µg/ml and 3 µg/ml) in rats of different ages. Also, amyloid ß scavengers expression was evaluated at different ages. For that, Real-time PCR and Western blot techniques were used. The results herein presented indicate differential expression of amyloid ß scavengers with age, sex and amyloid ß concentration. However, more studies are needed to investigate, for instance, the circadian oscillation of these genes in vitro with different amyloid ß concentrations and in vivo in Alzheimer´s Disease patients.