Gastrointestinal Disorders (Aug 2024)

Sex Differences and Bmal1/Acetylcholine- or Bmal1/Noradrenaline-Mediated Effects of Blue Light Irradiation on Dextran-Sodium-Sulfate-Induced Ulcerative Colitis Model Mice

  • Keiichi Hiramoto,
  • Sayaka Kubo,
  • Keiko Tsuji,
  • Daijiro Sugiyama,
  • Hideo Hamano

DOI
https://doi.org/10.3390/gidisord6030048
Journal volume & issue
Vol. 6, no. 3
pp. 720 – 732

Abstract

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Humans are exposed to significant amounts of blue light from computers and smartphones. However, the effects of blue light on ulcerative colitis remain unclear. In this study, we assessed blue-light-irradiation-induced alterations in colonic symptoms using a dextran sodium sulfate (DSS)-induced ulcerative colitis model mice. Both male and female institute of cancer research (ICR) mice were administered DSS (5%) ad libitum for 5 days while irradiated with 40 kJ/m2 blue light daily. Additionally, tranexamic acid (TA) was administered daily throughout the study. Male mice treated with DSS/blue light exhibited exacerbated colitis compared to those treated with DSS alone. In contrast, female mice treated with DSS/blue light exhibited enhanced symptoms compared to those treated with DSS alone. Additionally, in male mice exposed to blue light, the clock/brain and muscle Arndt-like 1 (Bma1)/noradrenaline/macrophage or beta2-adrenergic receptor (β2-AR) pathways were activated. In female mice, the Bmal1/acetylcholine/macrophage/nicotinic acetylcholine receptor alpha 7 (α7nAChR) pathway was activated. These findings highlight sex differences in the effects of blue light on DSS-induced ulcerative colitis. Moreover, the worsening of symptoms in males was ameliorated through TA administration.

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