AZD1080

AZD1080 is a selective, orally active, brain permeable GSK3 inhibitor, inhibits human GSK3α and GSK3β with a K_i of 6.9 nM and 31 nM, respectively, shows >14-fold selectivity against cdk2, cdk5, cdk1 and Erk2. AZD1080 inhibits tau phosphorylation in cells expressing human tau, with IC50 of 324 nM. ^[1]

3T3 fibroblasts are engineered to stably express four-repeat tau protein. These cells have high endogenous levels of GSK3 that is able to phosphorylate tau protein constitutively. This phosphorylation is inhibited by LiCl. After treatment with different compounds, cultures are washed twice with 5 mM MgCl₂-PBS.  The samples are homogenized at 4 °C, and protein content is determined by Bradford method. Total protein (25 μg) is electrophoresed on 10% SDS-PAGE gel and transferred to a nitrocellulose membrane. The experiments are performed using the following primary antibodies: tau Ser(P)-396, 1:1000; Tau5, 1:1000; and anti-GSK3β, 1:1000. The filters are incubated with the antibody at 4 °C overnight in 5% nonfat dried milk. A secondary antibody (1:5000), followed by ECL detection reagents are used for immunodetection. Quantitation of immunoreactivity is performed by densitometric scanning.

AZD1080 inhibits tau phosphorylation in rat brain after oral dministration, with brain/plasma exposure ratio of 0.5 – 0.8 at peak concentrations. AZD1080 reverses cognitive deficits and rescues dysfunctional synapses in mice. Acute oral treatment with AZD1080 inhibits peripheral GSK3 activity, produces a dose-dependent reduction of the phosphorylated to total glycogen synthase (GS) ratio, with a mean maximal inhibitory effect of 49% at the highest dose (10 μmol/kg) at 2 h after dosing. ^[1]