REM sleep deprivation increases the expression of interleukin genes in mice hypothalamus

- We investigated the change of inflammatory gene expressions by REM SD in the hypothalamus.
- Among IL subfamily genes, REM SD increased most potently IL1β gene expression.
- IL subfamily genes, and in particular IL1β, might be involved in sleep regulation.

Recently, evidence has suggested the possible involvement of inflammatory cytokines in sleep deprivation (SD). In this study, we assessed the patterns of inflammatory gene regulation in the hypothalamus of REM SD mice. C57BL/6 mice were randomly assigned to two groups, SD (n = 15) and control groups (n = 15). Mice in the SD group were sleep-deprived for 72 h using modified multiple platforms. Microarray analysis on inflammatory genes was performed in mice hypothalamus. In addition, interleukin 1 beta (IL1β) protein expression was analyzed by the immunochemistry method. Through microarray analysis, we found that expressions of IL subfamily genes, such as IL1β (2.55-fold), IL18 (1.92-fold), IL11 receptor alpha chain 1 (1.48-fold), IL5 (1.41-fold), and IL17E genes (1.31-fold), were up-regulated in the hypothalamus of SD mice compared to the control. The increase in the expression of these genes was also confirmed by RT-PCR. Among these genes, the expression of IL1β was particularly increased in the hypothalamus of SD mice. Interestingly, we found that the protein expression of endogenous IL1β was also elevated in the hypothalamus of SD mice compared to the control mice. These results implicate that IL subfamily genes, and in particular, IL1β, may play a role in sleep regulation in the hypothalamus of REM SD mice.