Abstract:

Objective To detect the expression of DDX3 and casein kinase 1ε (CK1ε）in the brain stem of amyotrophic lateral sclerosis (ALS) transgenic mice and study the role of DDX3 and CK1ε in the degeneration of brain stem motor neurons of amyotrophic lateral sclerosis (ALS). Methods Thirty-three ALS transgenic mice were used in this study. The brain stem was dissected and collected at the early (95 days), middle (108 days) or late (122 days) stages. The expression of DDX3 and CK1ε in the brain stem of ALS transgenic mice, the distribution and co-localization of positive cells in the hypoglossal nucleus and facial nucleus of the brain stem were detected by RT-PCR, Western blotting and immunofluorescence technology. In each group, the same number of wild type littermates were selected as controls. Results The result of RT-PCR and Western blotting showed that compared with the wild type mice, the expression of DDX3 and CK1ε mRNA in the brain stem of ALS mice remained unchanged at day 95, day 108 and day 122. DDX3 and CK1ε protein levels were up-regulated at day 95 and day 108 but down-regulated at day 122 in the ALS mice brain stem group (P<0.01, P<0.001). The result of immunofluorescence showed that DDX3 and CK1ε positive cells were detected in the sublingual nerve and facial nerve of ALS mice and wild type mice brain stem. DDX3 and CK1ε were expressed in neurons, but not in astrocytes. The immunoreactivity of both DDX3 and CK1ε of ALS mice and wild type mice was different. Conclusion The abnormal expression of DDX3 and CK1ε in the brain stem is closely related to the pathogenesis of ALS.

Key words: Amyotrophic lateral sclerosis,   Brain stem, DDX3,   Casein kinase 1ε,   Western blotting,  ＲT-PCＲ,  Mouse