Targeted Lipidomics of Mitochondria in a Cellular Alzheimer’s Disease Model

Abstract

Alzheimer’s disease (AD) is neuropathologically characterized by the accumulation of Amyloid-β (Aβ) in senile plaques derived from amyloidogenic processing of a precursor protein (APP). Recently, changes in mitochondrial function have become in the focus of the disease. Whereas a link between AD and lipid-homeostasis exists, little is known about potential alterations in the lipid composition of mitochondria. Here, we investigate potential changes in the main mitochondrial phospholipid classes phosphatidylcholine, phosphatidylethanolamine and the corresponding plasmalogens and lyso-phospholipids of a cellular AD-model (SH-SY5Y APPswedish transfected cells), comparing these results with changes in cell-homogenates. Targeted shotgun-lipidomics revealed lipid alterations to be specific for mitochondria and cannot be predicted from total cell analysis. In particular, lipids containing three and four times unsaturated fatty acids (FA X:4), such as arachidonic-acid, are increased, whereas FA X:6 or X:5, such as eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), are decreased. Additionally, PE plasmalogens are increased in contrast to homogenates. Results were confirmed in another cellular AD model, having a lower affinity to amyloidogenic APP processing. Besides several similarities, differences in particular in PE species exist, demonstrating that differences in APP processing might lead to specific changes in lipid homeostasis in mitochondria. Importantly, the observed lipid alterations are accompanied by changes in the carnitine carrier system, also suggesting an altered mitochondrial functionality.

Study of the potential neuroprotective effect of Dunaliella salina extract in SH-SY5Y cell model

“…Nevertheless, PG is a precursor of cardiolipin (which content and FA composition have been confirmed to be altered in AD [ 44 ]), so it is understandable that these changes could be caused by alterations in the PG profile. A recent study has also shown that some PG species (18:2/16:0, 18:2/16:1, 18:2/18:1, 18:2/18:2, 18:2/20:3, and 18:2/20:4) with FAs mainly found in cardiolipin are increased in a cellular AD model in comparison to a control cell [ 11 ]. Based on those studies, our results suggest that the decrease of some PGs together with the increase of PUFAs could be related with the neuroprotective potential of the DS extract against the different AD toxic agents.…”

“…SH-SY5Y cells present a mature neuron-like phenotype when differentiated with retinoic acid (RA) and brain-derived neurotrophic factor (BDNF), simulating the early-stage pathophysiology of cholinergic neurons affected by AD [9]. Previous works have analyzed the lipidomic composition of this cell line [10] and, more recently, the potential changes in mitochondrial phospholipid classes of SH-SY5Y transfected cells to simulate an AD model [11]. Moreover, the effect of an olive extract on these cells has also been evaluated in terms of lipid alterations [12].…”

In vitro Neuroprotective Potential and Lipidomics Study of Olive Leaves Extracts Enriched in Triterpenoids

“…Among the different in vitro models used to study AD, the SH-SY5Y cell line has been widely used as a first step for investigating and assessing the neuroprotective effects of natural compounds because of their possible differentiation into neuron-like cells ( 17 , 43 ). The in vitro toxicity results obtained in this study indicate that 20 and 40 μg/mL concentrations of OL-SS did not alter the cell viability of differentiated SH-SY5Y in comparison to control cells after 24 h, so the highest concentration (40 μg/mL) was selected to pre-treat the cells before the addition of 30 μM of the neurotoxic agent Aβ1–42 [the concentration used was based on previous studies ( 19 , 44 )]. As a result, the pre-treatment with OL-SS before the addition of Aβ1–42 for another 24 h was able to attenuate cell death caused by Aβ1–42.…”

“…This cell line is of human origin, catecholaminergic, easy to maintain, and reported to be differentiable into a more mature neuron-like phenotype ( 16 , 17 ). The global lipid analysis of this cell has been determined in a previous work ( 18 ), as well as the potential changes in the main mitochondrial phospholipid classes in a cellular AD-model ( 19 ). This cell line has been also used to evaluate the neuroprotective potential of different compounds, such as olive biophenols ( 20 ).…”

Impact of Vitamin D3 Deficiency on Phosphatidylcholine-/Ethanolamine, Plasmalogen-, Lyso-Phosphatidylcholine-/Ethanolamine, Carnitine- and Triacyl Glyceride-Homeostasis in Neuroblastoma Cells and Murine Brain

“…Prior to mass spectrometry analysis, lipids from a 100 µg sample were extracted using the solid/liquid lipid extraction method as described earlier in detail [ 43 , 44 , 45 ]. Afterward, shotgun lipidomics was performed on a 4000-quadrupole linear-ion trap (QTrap,) equipped with a Turbo Spray ion source from AB Sciex (Darmstadt, Germany) and couplet to an autosampler of the Agilent HPLC 1200 series (Santa Clara, CA, USA).…”