High-dose radiotherapy exposure is associated with normal tissue damage. Moreover, accumulating evidence from the Japanese atomic bomb survivors, Chernobyl liquidators, US astronauts, and some other exposed groups suggest that non-cancer effects also have been observed after moderate/low dose exposure in humans, in particular cardiovascular, respiratory, renal, and brain damage. The late onset of cardiovascular and kidney disease may be highly associated with ionizing radiation, but underappreciated. The exact pathogenesis and/or mediators involved in these chronic disease remain under investigation. Typically, as the senescent cell fraction following irradiation is known to increase, we examined whether ionizing radiation causes the renal injury by inducing cellular senescence. We assessed the effects of ionizing radiation on mouse inner medullary collecting duct- 3 (mIMCD-3) cells and Madin-Darby Canine Kidney (MDCK) cells, which predominantly used in vitro renal epithelial cells. We found that irradiation on mIMCD-3 and MDCK cells induced cellular senescence. Notably, the gene expression level of neuraminidase Klotho, highly expressed in renal cells/tissues with anti-senescence activity, was considerably decreased in irradiated mIMCD-3 cells and also kidney tissues of radiation-exposed mice. However, the protein level of klotho was persistent after radiation exposure. One of the negative regulators of klotho, Tumor necrosis factor-α (TNF-α) was significantly increased in both of irradiated mIMCD-3 cells and kidney tissues of mice. Critically, a Disintegrin and metalloproteinase domain-containing protein 9/10/17 (ADAM9/10/17), which functions as ectodomain shedding enzyme of klotho, was decreased in irradiated mouse renal cells/tissues. Collectively, our data suggest that TNF-α-mediated inhibition of klotho expression with blocking of soluble klotho formation following irradiation may contribute to the development of renal dysfunction through the acceleration of radiation-induced cellular senescence.
저자
Eun Ju Kim [ Division of Basic Radiation Bioscience, Korea Institute of Radiological and Medical Sciences, Seoul, 01812, Korea ]
Minyoung Lee [ 이민영 | Laboratory Animal Cencer, Korea Institute of Radiological and Medical Sciences, Seoul, 01812, Korea ]
본 학회는 화학, 생화학, 분자생물학, 미생물학, 식품공학, 의학, 약학, 유전공학 및 생물공학, 환경 및 기타 공업 등 전 분야의 탄수화물관련 이론과 기술을 연구 발전시키고 산학협동을 통해 이를 보급하여 국내 관련 산업의 발전 및 국민생활의 과학화에 기여하고자 하며, 이러한 목표와 비젼의 실현을 위해 회원들이 적극적인 참여와 활동을 전개하고자 한다.