AUTHOR=Zhao Danyang , Yang Lei , Han Peng , Zhang Haihui , Wang Fanjun , Meng Zhiyun , Gan Hui , Wu Zhuona , Sun Wenzhong , Chen Chuan , Dou Guifang , Gu Ruolan 

TITLE=Blocking TRAIL-DR5 signaling pathway with soluble death receptor 5 fusion protein mitigates radiation-induced injury

JOURNAL=Frontiers in Pharmacology

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2023.1171293

DOI=10.3389/fphar.2023.1171293

ISSN=1663-9812

ABSTRACT=The increasing application of nuclear technology, the high fatality of acute radiation syndrome (ARS) and its complex mechanism make ARS a global difficulty that requires urgent attention. Here we reported that the death receptor 5(DR5), as well as its ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), were both significantly up-regulated after irradiation in mice with 6 Gyγ-ray single radiation. And by intravenously administrated with soluble DR5 fusion protein (sDR5-Fc), the competitive antagonist of DR5, the excessive apoptosis in the radiation-sensitive tissues such as spleen and thymus were significantly inhibited and the radiation-induced damage of spleen and thymus were mitigated, while the expression of apoptosis-inhibiting proteins such as Bcl-2 was also significantly up-regulated. The biochemical indicators such as serum ALP, AST, ALT, TBIL, K and Cl levels that affected by radiation, were improved by sDR5-Fc administration too. For in vitro studies, it had been found that sDR5-Fc effectively inhibited apoptosis of human small intestinal mucosal epithelial cells and IEC-6 cells in vitro using flow cytometry. Finally, survival studies showed that mice administrated with sDR5-Fc after 9 Gy γ-rays single whole body radiation effectively increased the 30-day survival and was in a significant dose-dependent manner. Overall, the findings revealed that DR5/TRAIL-medicated apoptosis pathway had played important roles in the injury of ARS mice, and DR5 probably be a potential target for ARS therapeutics. And the DR5 apoptosis antagonist, sDR5 fusion protein, probably is a promising anti-ARS drug candidate which deserves further investigation.