BACKGROUND: Several immunological functions are dependent on circadian rhythms. However, there are still relatively few studies about circadian rhythms in neuromyelitis optica spectrum disorders (NMOSD) and 2D2 transgenic mice. We explore whether 2D2 mice have abnormalities in circadian rhythms and the potential underlying molecular mechanism.

MATERIAL AND METHODS: We first observed the wheel-running motion of the control and 2D2 mice using wheel-running measurements. The cytokine levels were also analyzed using enzyme-linked immunosorbent assay (ELISA), and the results of clock gene expressions in the suprachiasmatic nucleus (SCN) were investigated using real-time polymerase chain reaction (real-time PCR).

RESULTS: The wheel-running rhythm in 2D2 mice differed from that of the controls. The TNF-α and IL-10 rhythms were disrupted in 2D2 mice. Additionally, the rhythm of the clock genes, Per1 and Per2, and expression in the SCN of 2D2 mice were also changed.

CONCLUSIONS: The results presented here indicate that alteration of circadian rhythms in 2D2 mice affects behavior and immune function, and the potential molecular mechanism might be the Per1 and Per2 expression disorders in the SCN. 2D2 mice might be a suitable model for studying circadian disruption in NMOSD.

Keywords: Behavior, Circadian clocks, Circadian Rhythm, Cytokines, Mice, Transgenic, Neuromyelitis Optica