Fig. 6

Administration of mIL-21 directly potentiates neuronal death following oxygen glucose deprivation conditions, induces Caspase 3/7-mediated apoptosis and activates JAK/STAT pathway in vitro. a Representative images of in vitro primary neurons under normoxic conditions (panel 1), oxygen glucose deprivation (OGD) conditions followed by exposure to complete media for 24 h (panel 2), OGD conditions followed by exposure to complete media with mIL-21 (1 ng/ml) for 24 h (panel 3), OGD conditions followed by exposure to complete media with mIL-21 (10 ng/ml) for 24 h (panel 4), and OGD conditions followed by exposure to complete media with mIL-21 (100 ng/ml) for 24 h (panel 5). Scale bar = 10 μm. b Quantification of primary neuron survival utilizing trypan blue cell exclusion assay following Normoxic conditions, OGD conditions followed by exposure to complete media for 24 h, as well as OGD conditions followed to exposure to complete media with mIL-21 (1 ng/ml, 10 ng/ml, and 100 ng/ml) for 24 h (n = 5). c Representative flow cytometry histograms of Caspase 3/7 activity on primary neurons treated with OGD conditions for 90 min followed by 24 h of normoxic conditions with control or mIL-21 (100 ng/ml) for 24 h. d Quantification of the percentage of neurons expressing Caspase 3/7 (n = 5). e Relative fold change of JAK/STAT pathway related phosphorylated proteins following IL-21 treatment compared to control-treated neurons in vitro. f Schematic of IL-21 activity on neurons. Data are combined from three independent experiments. Data represent mean ± s.e.m. Data represent mean ± s.e.m. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. n.s. not significant. One-way ANOVA followed by Dunn’s post hoc test (b). Student’s t test followed by Mann–Whitney U test (d)