Dose-dependency and reversibility of radiation-induced injury in cardiac explant-derived cells of mice

Lan Luo,Shinji Goto,Yoshishige Urata,Chen Yan,Tao-Sheng Li,Chang-Ying Guo,Shouhua Zhang,Al Shaimaa Hasan

doi:10.1038/srep40959

Abstract

We evaluated the dose-dependency and reversibility of radiation-induced injury in cardiac explant-derived cells (CDCs), a mixed cell population grown from heart tissues. Adult C57BL/6 mice were exposed to 0, 10, 50 and 250 mGy γ-rays for 7 days and atrial tissues were collected for experiments 24 hours after last exposure. The number of CDCs was significantly decreased by daily exposure to over 250 mGy. Interestingly, daily exposure to over 50 mGy significantly decreased the c-kit expression and telomerase activity, increased 53BP1 foci in the nuclei of CDCs. However, CD90 expression and growth factors production in CDCs were not significantly changed even after daily exposure to 250 mGy. We further evaluated the reversibility of radiation-induced injury in CDCs at 1 week and 3 weeks after a single exposure to 3 Gy γ-rays. The number and growth factors production of CDCs were soon recovered at 1 week. However, the increased expression of CD90 were retained at 1 week, but recovered at 3 weeks. Moreover, the decreased expression of c-kit, impaired telomerase activity, and increased 53BP1 foci were poorly recovered even at 3 weeks. These data may help us to find the most sensitive and reliable bio-parameter(s) for evaluating radiation-induced injury in CDCs.

Highlights

In this study, we first daily exposed mice to different doses of γ-rays (0 to 250 mGy/day) for 7 days, and detected the dose-dependency of radiation-induced injury in CDCs by various bio-parameters
This study was designed to examine the dose-dependency and reversibility of radiation-induced injury in cardiac explant-derived cells, a mixed population of cardiac stem cells and supporting cells grown from heart tissues
By daily exposure of healthy mice to 0~250 mGy γ-rays for 7 days, we demonstrated that radiation exposure declined the number and c-kit expression, and induced cell senescence and DNA damage of CDCs in a dose-dependent manner

Summary

Introduction

We first daily exposed mice to different doses of γ-rays (0 to 250 mGy/day) for 7 days, and detected the dose-dependency of radiation-induced injury in CDCs by various bio-parameters. The percentage of cells with 53BP1 foci, a marker for DNA damage, was significantly increased in the CDCs from mice daily exposed to over 50 mGy γ-rays for 7 days (P < 0.01 vs 0 mGy, Fig. 3B).

Results

Conclusion