Fig. 7: SIVA-1 modulates AMPAR internalization in a caspase-dependent manner.

a Representative confocal images of neurons transfected with SIVA-1 or empty vector and treated with 10 μM of Q-VD (caspase inhibitor). Only GFP-positive cells (first column) were considered for quantification (left panel). Scale bar 10 µm. b The results of the quantification of internalized GluA2 vs. surface GluA2 were normalized to empty vector, untreated cells (right panel). Each point represents an independent experimental repeat in which 15–20 cells were analyzed. SIVA-1-transfected cells showed greater internalization of GluA2 receptor (F (1, 97) = 3.840), Q-VD treatment restored internalization to basal levels (F (1, 97) = 7.345). Two-way ANOVA ***p ≤ 0.001. c Representative confocal images of neurons transfected with vectors carrying shSIVA-1 or shScramble as control. The GluA2 internalization assay was performed in neurons treated with NMDA to stimulate LTD and in untreated neurons. Only GFP-positive cells (first column) were considered for quantification. Internalized GluA2 (second column, red in merge) and surface GluA2 (third column, green in merge) were measured. Scale bar 10 µm. d The results of the quantification of internalized GluA2 vs. surface GluA2 were normalized to shScrambled, untreated cells. Each point represents an independent experimental repeat in which 15–20 cells were analyzed. NMDA treatment induced GluA2 internalization in both shScrambled and shSIVA-1 cells (F (1, 84) = 167.1). However, shSIVA-1 cells treated with NMDA showed a significant decrease in receptor internalization (F (1, 84) = 33.5). Two-way ANOVA **p ≤ 0.01; ***p ≤ 0.001. shScr shScrambled.