Therapeutic radiation exposure of the abdomen during childhood induces chronic adipose tissue dysfunction

Exogenous APN protects normal tissues from radiation-induced oxidative damage and fibrosis in mice and prostate cancer patients with higher levels of APN have less radiation-induced toxicities

Radiation causes damage to normal tissues that leads to increased oxidative stress, inflammation, and fibrosis, highlighting the need for the selective radioprotection of healthy tissues without hindering radiotherapy effectiveness in cancer. This study shows that adiponectin, an adipokine secreted by adipocytes, protects normal tissues from radiation damage invitro and invivo. Specifically, adiponectin (APN) reduces chronic oxidative stress and fibrosis in irradiated mice. Importantly, APN also conferred no protection from radiation to prostate cancer cells. Adipose tissue is the primary source of circulating endogenous adiponectin. However, this study shows that adipose tissue is sensitive to radiation exposure exhibiting morphological changes and persistent oxidative damage. In addition, radiation results in a significant and chronic reduction in blood APN levels from adipose tissue in mice and human prostate cancer patients exposed to pelvic irradiation. APN levels negatively correlated with bowel toxicity and overall toxicities associated with radiotherapy in prostate cancer patients. Thus, protecting, or modulating APN signaling may improve outcomes for prostate cancer patients undergoing radiotherapy.

Potential role of gut microbiota-LCA-INSR axis in high fat-diet-induced non-alcoholic fatty liver dysfunction: From perspective of radiation variation

Non-alcoholic fatty liver disease (NAFLD) is a progressive disease of the liver covering a range of conditions from hepatic steatosis to liver fibrosis. NAFLD could be induced by High-fat-diet(HFD). Ionizing radiation is widely used in medical diagnosis and therapy as well as is a common risk factor in occupational environment. Whether the exposure of various dose of radiation has effects on HFD-induced NAFLD remains unclear. Here, we reported that radiation exposure promoted HFD-induced NAFLD in a dose-response manner. Furthermore, the gut microbiota composition had significant difference among mice with or without radiation treatment. Specifically, the Bacteroidetes/Firmicutes ratio, the abundance of A. muciniphila, Butyricococcus, and Clostridiaceae decreased significantly in the mice with co-exposure of high dose of radiation and HFD treatment. A fecal transplantation trial (FMT) further verified the role of gut microbiota in the regulation of the liver response to co-exposure of high dose of radiation and HFD treatment. Notably, the gut microbiome analysis showed plasma lithocholic acid (LCA) level increased in the mice with co-exposure of high dose of radiation and HFD treatment. Following antibiotic and probiotic treatments there was a significantly decreased LCA bile acid concentration and subsequent promotion of INSR/PI3K/Akt insulin signaling in the liver tissues. Our results demonstrate that the co-exposure of radiation and HFD aggravates the HFD-induced NAFLD through gut microbiota-LCA-INSR axis. Probiotics supplementation is a potential way to protect against co-exposure of radiation and HFD-induced liver damage. Meanwhile, our study provide a new insight that population with potential HFD-induced damage should pay more attention on preventing from liver damage while exposing radiation.

•

Gut microbiota-lithocholic acid-insulin receptor (LCA-INSR) axis involves the promotion effects of radiation on HFD-induced NAFLD.

•

Probiotics improve the liver damage induced by co-exposure of radiation and HFD.