Thapsigargin affects presenilin-2 but not presenilin-1 regulation in SK-N-BE cells
Autor: | Roberto Rivabene, Annamaria Confaloni, Francesca Svetoni, Paolo Rosa, Paola Piscopo, Sergio Visentin, Alessio Crestini, Chiara De Nuccio |
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Jazyk: | angličtina |
Rok vydání: | 2013 |
Předmět: |
medicine.medical_specialty
Thapsigargin Down-Regulation Apoptosis Endoplasmic Reticulum General Biochemistry Genetics and Molecular Biology Presenilin Cell Line chemistry.chemical_compound Cytosol Alzheimer Disease Internal medicine mental disorders Presenilin-2 Amyloid precursor protein medicine Presenilin-1 Homeostasis Humans Enzyme Inhibitors Regulation of gene expression Protein Synthesis Inhibitors Brefeldin A biology Superoxide Dismutase Endoplasmic reticulum Neurodegeneration Biological Transport medicine.disease Cell biology Oxidative Stress Endocrinology chemistry Unfolded protein response biology.protein Alzheimer’s disease apoptosis calcium neurodegeneration oxidative stress presenilins Calcium |
Popis: | Presenilin-1 (PS1) and presenilin-2 (PS2) are transmembrane proteins widely expressed in the central nervous system, which function as the catalytic subunits of γ-secretase, the enzyme that releases amyloid-β protein (Aβ) from ectodomain cleaved amyloid precursor protein (APP) by intramembrane proteolysis. Mutations in PS1, PS2, and Aβ protein precursor are involved in the etiology of familial Alzheimer’s disease (FAD), while the cause of the sporadic form of AD (SAD) is still not known. However, since similar neuropathological changes have been observed in both FAD and SAD, a common pathway in the etiology of the disease has been suggested. Given that age-related deranged Ca2+ regulation has been hypothesized to play a role in SAD pathogenesis via PS gene regulation and γ-secretase activity, we studied the in vitro regulation of PS1 and PS2 in the human neuron-like SK-N-BE cell line treated with the specific endoplasmic reticulum (ER) calcium ATPase inhibitor Thapsigargin (THG), to introduce intracellular Ca2+ perturbations and mimic the altered Ca2+ homeostasis observed in AD. Our results showed a consistent and significant down-regulation of PS2, while PS1 appeared to be unmodulated. These events were accompanied by oxidative stress and a number of morphological alterations suggestive of the induction of apoptotic machinery. The administration of the antioxidant N-acetylcysteine (NAC) did not revert the THG-induced effects reported, while treatment with the Ca2+-independent ER stressor Brefeldin A did not modulate basal PS1 and PS2 expression. Collectively, these results suggest that Ca2+ fluctuation rather than ER stress and/or oxidative imbalance seems to play an essential role in PS2 regulation and confirm that, despite their strong homology, PS1 and PS2 could play different roles in AD. |
Databáze: | OpenAIRE |
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