Animals
Six to seven -week old male wild-type C57BL/6 mice (18-22 g body weight) were purchased from Vital River Laboratory and Animals Co., Ltd. (Beijing, China). The animals were housed in a specific pathogen free environment, at a temperature of 22-26℃ with humidity of 60-70%, where a 12-hour day/night cycle was maintained. The mice had free access to standard laboratory food and fresh water. The laboratory animal management rules of Tongji Medical College of Huazhong University of Science and Technology were strictly abided by.