Delayed Luminescence for in vitro study of mitochondrial dysfunctions in neurodegenerative diseases

摘要

Spectroscopic studies of Delayed Luminescence emitted by an in vitro model for studying of the effects of amyloid-βeta(Aβ) have been performed. Aβ is a neurotoxic protein overexpressed in Alzheimer's Disease (AD), which is also relatedto mitochondrial dysfunction. The experiments have been carried out on primary Olfactory Ensheathing Cells (OECs)cultures. Cells have been exposed to Aβ(1-42) native full-length peptide or to Aβ(25-35), a toxic fragment of Aβ, orAβ(35-25), a non toxic Aβ fragment, both in absence and in presence of Astaxanthin, a well-known antioxidant agent.To monitor cell viability, MTT test was used. Reactive oxygen species and reduced glutathione levels were utilized totest the oxidative intracellular status. We also assessed the expression of some glial markers (Glial Acidic FibrillaryProtein, Vimentin), of Nestin, stem cell marker, and the activation of the apoptotic pathway assessing caspase-3cleavage. We found that, in OECs, Glial Acidic Fibrillary Protein, Vimentin expression and caspase-3 exhibited asignificant enhancement in Aβ(1–42) and Aβ(25–35) exposed cells. The pre-treatment with Astaxanthin restored thelevels of Vimentin and caspase-3 to control values, increasing also Nestin expression levels and reestablished theintracellular oxidative status modified by the exposure to Aβ(1–42) or Aβ(25–35) of OECs. DL intensity and kineticschanges as a function of the treatments were also measured. In particular, an increase in DL emission, with respect theuntreated cells (controls), was observed in cells exposed to Aβ(25-35) fragment. This emission appeared quenched inpresence of Astaxanthin.