OBJECTIVE: This study aimed to evaluate the treatment paradigm of a single dose of GSK-3 inhibitor administration at various time courses for the protection of the CNS from EAE.

MATERIALS AND METHODS: Effects of GSK-3 inhibition on intracellular cytokine levels were evaluated from in vitro naïve CD4+ T cell cultures. Immunized C57BL/6 female mice with MOG35-55 in conjunction with CFA and Ptx were used as a chronic inflammatory EAE disease model. Tideglusib (NP12), a Thiadiazolidinone class, selective, and non-ATP competitive GSK-3 inhibitor, was injected intraperitoneally at pre-EAE, same-day of immunization or disease onset. After 30 days post-immunization, brain, and spinal cord tissues were collected for inflammation and demyelination analysis by H&E and luxol fast blue staining, respectively, whereas cytokine profiles of the serum were assessed by cytokine beads array.

RESULTS: The inhibition of GSK-3 in CD4+ T cells increased IL-10 production. The administration of Tideglusib during pre-EAE and same-day, but not during disease onset, significantly reduced clinical symptoms and delayed disease onset. Histopathological analysis of spinal cord tissues showed a significant decline in the number of inflammatory cell infiltration with a concomitant reduction in demyelination through the blocking of GSK-3, especially during pre-EAE and sameday. Upregulation of IL-10 via GSK-3 inhibition coincided with the downregulation of cytokineassociated effector T cells, including IFN-γ, IL-9, IL-17A, IL-17F, IL-21, and IL-23. Increased IL-4 production, however, was only significant in the pre-EAE group.

METHODS: Six master dies were duplicated from the prepared maxillary first premolar tooth using nonprecious metal alloy (Wiron 99). Thirty copings (Procera AllCeram) of 0.6-mm thickness were manufactured. Three types of luting media were used: zinc phosphate cement (Elite), glass ionomer cement (Fuji I), and dual-cured composite resin cement (Panavia F). Ten copings were cemented with each type. Two master dies were used for each group, and each of them was used to lute five copings. All groups were cemented according to manufacturer's instructions and received a static load of 5 kg during cementation. After 24 hours of distilled water storage at 37 degrees C, the copings were vertically compressed using a universal testing machine at a crosshead speed of 1 mm/min.

RESULTS: ANOVA revealed significant differences in the load at fracture among the three groups (p < 0.001). The fracture strength results showed that the mean fracture strength of zinc phosphate cement (Elite), glass ionomer cement (Fuji I), and resin luting cement (Panavia F) were 1091.9 N, 784.8 N, and 1953.5 N, respectively.