Mouse model of LPS-induced sepsis

Male C57BL/6J mice that were 10–12 weeks old and weighed 20–25 g were provided by the Animal Center of China Medical University (Shenyang, China). The mice were housed in the animal center under standard conditions (23±2°C, 65±5% humidity, 12 h light/dark cycle) with access to food and water ad libitum. The mice were randomly assigned into three groups as follows: Control, LPS and LPS + UFH, (12 mice/group). To induce sepsis, LPS derived from Escherichia coli 055:B5 (Sigma-Aldrich; Merck KGaA, Darmstadt, Germany) was administered via an intraperitoneal injection at a dose of 20 mg/kg body weight, while the control mice were administered an intraperitoneal injection of 100 µl saline. UFH with a mean molecular weight of 12,000 Da (Shanghai no. 1 Biochemical and Pharmaceutical Co., Ltd., Shanghai, China) was administered via the tail vein (5 U/20 g of body weight) 30 min prior to LPS administration, and the other two groups received an equal amount of saline.

The animal care and experimental procedures were conducted in accordance with the Guide for the Care and Use of Laboratory Animals (23), and the protocol was approved by the Institutional Animal Care and Use Committee of China Medical University.