2937 - Short Chain Fatty Acids for Prevention and Treatment of Radiation Lung Injury

X. Zhou, J. Xue, and Q. Zhao; 1st Affiliated Hospital of Soochow University, Suzhou, China

Purpose/Objective(s): Radiotherapy plays a very important role in the treatment of thoracic tumors, but treatment-related lung injury exists, and there is no effective prediction and treatment measures at present. CD8+T cell infiltration is an effective predictor of pneumonia, granzyme B imaging can objectively reflect the infiltration of CD8+T cells, and then predict the occurrence of radiation lung injury. Short-chain fatty acids(SCFAs) can regulate the response of CD8+T cells, and exogenous supplementation of SCFAs can prevent and treat radiation lung injury. Materials/

Methods: The whole lung of mice irradiated by linear accelerator 15Gy was used to construct the animal model of radiation lung injury, and SCFAs was supplemented in drinking water. Monthly 18F-FDG scanning was performed with Micro-pet/ct to monitor pulmonary inflammation, and correlation analysis was performed with granulozyme B imaging for pneumonia incidence. The lung tissues of mice 60 days and 180 days after irradiation were stained to analyze the lung injury. Beas-2b cells were irradiated with 10Gy to construct a radiation-induced lung injury model in vitro, supplemented with SCFAs, and detected apoptosis, senescence, intracellular ROS, and DNA damage.
Results: It was found that granzymin B imaging and CD8+Tcell infiltration levels were higher in patients with lung injury. In a radiation-induced lung injury mouse model, prophylactic combined therapeutic supplementation with SCFAs significantly reduced the incidence of lung inflammation in mice compared with direct irradiation (SUVmean: 0.51 vs 0.36, P<0.05). At the cellular level, exogenous sodium propionate supplementation can reduce DNA double-strand breaks, reduce intracellular ROS levels after ionizing radiation, and improve cell survival.
Conclusion: The infiltration of CD8+T cells is associated with radiation lung injury, and granzymin B imaging can effectively predict the occurrence of radiation lung injury. SCFAs can effectively regulate body immunity, and exogenous SCFAs supplementation is an effective way to reduce the incidence of radiation lung injury.