Jiying Wang1, Yong Cai2, Zhaoying Sheng2. 1. Department of Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, China. 2. Department of Radiation Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, China.
Abstract
BACKGROUND: Sirtuin 6 (SIRT6) can increase the radiosensitivity of non-small cell lung cancer and exert protective effects on radiation-induced lung injury. OBJECTIVES: To investigate protective effects of SIRT6 overexpression on radiation-induced lung injury in rats. MATERIAL AND METHODS: Male Wistar rats (n = 72) were randomly divided into 3 groups. Models were made by radiating both lungs with a 6MV X linear accelerator. Each group was injected through the tail vein with normal saline (the control group and radiation group) and lentivirus carrying overexpressed SIRT6 (the Lent-SIRT6 group) on the same day as the modeling. Routine blood indexes (white blood cells (WBC), red blood cells (RBC), neutrophils and lymphocytes) were recorded; the rats were sacrificed and their lung tissues taken; pathological changes in the lungs were evaluated using hematoxylin and eosin (H&E) staining; and tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and interleukin 1β (IL-1β) were detected with enzyme-linked immunosorbent assay (ELISA) 8 weeks after radiotherapy. RESULTS: The lung structure including alveolar walls and interstitium in the control group was normal, but the alveolar walls in the radiation group were obviously thickened and a large amount of hyperplastic fibrous tissue was found in the alveolar interstitium. The thickness and interstitial fibrosis of the alveolar walls were more alleviated in the Lent-SIRT6 group than in the radiation group. Compared with those in the control group, the respiratory rates, levels of TNF-α and IL-6 in serum, neutrophils and levels of TNF-α, IL-6 and IL-1β in the liver all were increased, while WBCs and lymphocytes were decreased in the radiation group. The respiratory rates, levels of TNF-α and IL-6 in serum, neutrophils and levels of TNF-α, IL-6 and IL-1β in the liver were all decreased, and WBCs and lymphocytes were increased after injection with lentivirus carrying overexpressed SIRT6. CONCLUSIONS: Sirtuin 6 inhibits inflammation and alleviates radioactive pneumonia and lung injury. Therefore, SIRT6 can exert certain protective effects on lung injury.
BACKGROUND:Sirtuin 6 (SIRT6) can increase the radiosensitivity of non-small cell lung cancer and exert protective effects on radiation-induced lung injury. OBJECTIVES: To investigate protective effects of SIRT6 overexpression on radiation-induced lung injury in rats. MATERIAL AND METHODS: Male Wistar rats (n = 72) were randomly divided into 3 groups. Models were made by radiating both lungs with a 6MV X linear accelerator. Each group was injected through the tail vein with normal saline (the control group and radiation group) and lentivirus carrying overexpressed SIRT6 (the Lent-SIRT6 group) on the same day as the modeling. Routine blood indexes (white blood cells (WBC), red blood cells (RBC), neutrophils and lymphocytes) were recorded; the rats were sacrificed and their lung tissues taken; pathological changes in the lungs were evaluated using hematoxylin and eosin (H&E) staining; and tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and interleukin 1β (IL-1β) were detected with enzyme-linked immunosorbent assay (ELISA) 8 weeks after radiotherapy. RESULTS: The lung structure including alveolar walls and interstitium in the control group was normal, but the alveolar walls in the radiation group were obviously thickened and a large amount of hyperplastic fibrous tissue was found in the alveolar interstitium. The thickness and interstitial fibrosis of the alveolar walls were more alleviated in the Lent-SIRT6 group than in the radiation group. Compared with those in the control group, the respiratory rates, levels of TNF-α and IL-6 in serum, neutrophils and levels of TNF-α, IL-6 and IL-1β in the liver all were increased, while WBCs and lymphocytes were decreased in the radiation group. The respiratory rates, levels of TNF-α and IL-6 in serum, neutrophils and levels of TNF-α, IL-6 and IL-1β in the liver were all decreased, and WBCs and lymphocytes were increased after injection with lentivirus carrying overexpressed SIRT6. CONCLUSIONS:Sirtuin 6 inhibits inflammation and alleviates radioactive pneumonia and lung injury. Therefore, SIRT6 can exert certain protective effects on lung injury.