Cell cultures and Aβ treatment

SH-SY5Y cells were differentiated with all-trans-retinoic acid (Sigma) and brain-derived neurotrophic factor (BDNF, Sigma Aldrich, MO, USA), and suspensions of β-amyloid 1–42 peptide (Aβ42, final concentration of 10 μM: American Peptide Company Inc.) were added every other day over 4 consecutive days. Subsequently, the medium was removed, and the cells were suspended in 100 μL of solubilization buffer and processed as described above. Cells cultured in 96-well plates and treated as described above were assessed for viability using the tetrazolium assay (MTS: CellTiter 96^® AQueous Assay, Promega, Southampton, UK).

The primary cortical neuron cultures were performed as in Cuchillo-Ibanez et al.¹⁹. Briefly, neurons from cortical lobes of E16.5 mice embryos were plated onto 35-mm dishes (1.3 × 10⁶ cells/dish) and maintained in Neurobasal medium (Invitrogen) containing B27 supplements (GIBCO BRL), 100 IU/ml penicillin, 100 μg/ml streptomycin and 2 mM glutamine. After 7 days, cortical neurons were treated for 45 min with Neurobasal medium (mock), ~10 nM Reelin or 10 nM Reelin together with 2 μM synthetic Aβ42 (American Peptide Company Inc, Vista, CA, USA).