Animals

α7nAChR knockout mice (α7nAChR^−/−, background, C57BL/6J, B6.129S7-Chrna7tm1Bay/J, stock no. 003232) were purchased from Jackson Laboratory (Bar Harbor, ME, USA) [13]. Littermate wild-type mice (α7nAChR^+/+, background, C57BL/6J, 6–8 weeks old) were used as controls. The mice were housed with free access to food and water in 12-h dark/light cycles. Anesthetization was induced by intraperitoneal injection of pentobarbital sodium (80 mg/kg). Subsequently, FGF10 (5 mg/kg) dissolved in phosphate-buffered saline (PBS) or PBS with equal volume was intratracheally delivered. Three days later, mice were intratracheally injected with 2.5 mg/kg of LPS dissolved in PBS. Mice were humanely sacrificed by lethal overdose of pentobarbital sodium on the 7th day. Animal experiments were approved by the Committees on Animal Research of the Institut Pasteur of Shanghai, Chinese Academy of Sciences, China. The protocols were performed in accordance with the United States National Institutes of Health Guide for the Care and Use of Laboratory Animals (8th Edition, 2011).