Cutting-edge contributions from invited poster
presentations providing significant research works in the fifth International
Symposium for Medicinal Sciences (ISMS) in the 139th Chiba annual meeting in
2019 are assembled for the Current Topics section in this issue of the Biological
and Pharmaceutical Bulletin.
Mao et al. found that
resveratrol can significantly inhibit the expression of SUMO1. They demonstrate
that resveratrol alleviates inflammatory bowel disease (IBD) in mice by inhibiting
the expression of SUMO1 molecule, and by modulating the activation of wnt/β-catenin
signaling pathway. Clinical analysis also proves that the expression of SUMO1
and β-catenin molecules increased with the worsening of the disease, which also
provides a new method for clinical diagnosis and treatment of IBD.
Edoxaban is an oral
anticoagulant used for preventing and treating stroke or systemic embolism. Bleeding
is the most common complication associated with anticoagulants. In particular,
severe bleeding is assumed to be related to
mortality in patients treated with anticoagulation
therapy. However, few studies have examined the risk factors for bleeding in
Japanese patients receiving edoxaban. The article by Takase et al. revealed
that a low baseline hemoglobin level was a significant risk factor for major and clinically relevant bleeding in Japanese patients receiving edoxaban.
The article by Tanaka et al. proposed a novel
mechanism of radioresistance and candidate for use as radiosensitizers in
radiation therapy of melanoma. A2B receptor was involved in radioresistance via
DNA damage response in B16 cells. A2B receptor antagonist enhances tumor growth-inhibitory
effect by gamma-ray and shows radiosensitizing effect in vivo. These
findings proposed that A2B receptor contributes to radioresistance, and could be a new target for the development of
agents to increase the efficacy of radiotherapy.
CD81
is important for regulating biological processes such as B cell receptor
signaling and B cell differentiation. However, little is known about degradation
mechanism of CD81. Hosokawa et al. demonstrated that CD81 on the cell surface is
degraded by lysosome via K63- and K29-linked poly-ubiquitination. The poly-ubiquitinated
CD81 is translocated from the cell surface into endosomes and is degraded by
lysosomes. This is the first report showing that the lysosomal degradation of
CD81 requires poly-ubiquitination
and clathrin-mediated endocytosis.