Figure 6. Trx80 is not pro-inflammatory in glia but inhibits Aβ(1–42) aggregation and toxicity.

1. Nitric oxide production was measured in mixed glial primary cultures from rat in response to Trx80 stimulation (10 nM) in combination with different inflammatory modulators. LPS = lipopolysaccharide (100 ng/ml); C = untreated cells; Aβ(1–42) (10 µM); Aβ(1–40) (10 µM); E3 = apoE3 (10 nM); E4 = apoE4 (10 nM). Data are expressed as ng of nitrites produced per µg of total protein. Bars represent mean values of three experiments ± SEM.
2. Trx80 (1 and 5 µM) inhibited the fibrillar aggregation of Aβ(1–42) (20 µM) detected by fluorescence Thioflavin-T assay. Lower Trx80 concentrations were without effect.
3. Aβ(1–42) (10 µM, 24 h) reduced cell viability in non-transfected (NT) and in Trx80 (100 nM)-treated SH-SY5Y cells. Aβ(1–42) was harmless when pre-incubated with Trx80 (100 nM) or added to Trx80-transfected (Trx80-T) cells. Data are expressed as percentage of the respective control and bars represent mean values of four experiments ± SEM (ANOVA followed by Bonferroni's PLSD post hoc test; ***p = 0.001, *p = 0.04).
4. Aβ-rich fractions (1 µl) extracted from one AD brain (Aβ-AD) reduced cell viability of SH-SY5Y cells. The Aβ-AD effect was partially inhibited by addition of Trx80 (100pM) or by overexpression of Trx80 (Trx80T). Treatment with extracts from a plaque-free control brain (C) did not harm the cells. Data are expressed as percentage of values in buffer treated cells, and bars represent mean values of 9 experiments ± SEM (ANOVA followed by Bonferroni's PLSD post hoc test; ***p = 0.001 against controls; #p = 0.01 against Aβ-AD).
5. Overexpression of Trx1 (Trx1-T) was partially protective against Aβ(1–42) (10 µM, 24 h) even under ADAM10/17 inhibition (GW280264X, 10 µM). Data from four experiments are shown as percents of MTT values from controls (untreated cells, NT) ± SEM (ANOVA followed by Bonferroni's PLSD post hoc test; ***p = 0.001).