Paradoxical sleep deprivation induces differential biological response in rat masticatory muscles: Inflammation, autophagy and myogenesis

Background: The aim of this study was to evaluate whether sleep deprivation (SD) induces inflammation, autophagy and myogenesis in the following masticatory muscles: masseter and temporal.

Methods: In this study, 18 animals were randomly distributed into three groups: control group (CTL, n = 6), SD for 96 hours (SD96, n = 6), and SD for 96 hours and more 96 hours of sleep recovery (SD96 + R, n = 6).

Results: In the histopathological analysis, SD 96 was able to induce inflammation in masseter and temporal. Nevertheless, the lack of inflammatory process was evidenced to the masseter in the group SD96 + R. Upregulation of TNF-alpha production was detected in the SD96 group, while SD96 + R decreased TNF immunoexpression for both skeletal muscles evaluated. MyoD and myogenin increased in rats submitted to SD96. By contrast, the levels of MyoD decreased in the group SD96 + R. Myogenin pointed out high immunoexpression in SD96 + R groups. In temporal, pAkt decreased in animals submitted to SD96, but it increased in the group SD96 + R. The levels of LC3 protein increased in both skeletal muscles studied, and masseter decreased LC3 protein expression in the SD96 + R.

Conclusion: In summary, our results demonstrate that SD is able to induce inflammation, atrophy and myogenesis in rat masticatory muscles, being more intense in temporal when compared to masseter.