Male C57BL/6 mice weighing approximately 20–22 g and male Kunming (KM) mice weighing approximately 35–40 g were obtained from the Experimental Center of Lanzhou University. Animals were reared in a clean house under a 12-h light/dark cycle, temperature of 22–25 °C, and humidity of 50–60%. Mice were fed with regular diet and purified water ad libtum. All experiments were conducted in accordance with the guidelines of the Policies Governing the Use of Live Vertebrate Animals of the Lanzhou University.