CRID3, a Blocker of Apoptosis Associated Speck Like Protein Containing a Card, Ameliorates Murine Spinal Cord Injury by Improving Local Immune Microenvironment

Abstract

demonstrated that inflammasomes may play an important role in the inflammation of SCI. Because ASC is the adaptor protein shared by inflammasomes, we speculated that ASC can be used as a target to inhibit the activation of inflammasomes, so as to improve the local immune microenvironment of SCI and reduce nerve damage. In this study, CRID3, a blocker of ASC oligomerization [18], was used to study its effect on the local microenvironment and the possible role in neuroprotection following SCI. Methods Animals A total of 120 female C57BL/6 mice (weight, 18-20 g; age, 8 weeks old) obtained from Chang Zhou Cavens Laboratory Animal Ltd. Animals were housed in ventilated cages and maintained on a 12-hour light/dark cycle with ad libitum access to food and water. Ambient room temperature was maintained at 20 ~ 22 °C with 30 ~ 70% humidity. Animal care following surgery complied with the regulations for the management of experimental animals (revised by the Ministry of Science and Technology of China in June 2004). The study was approved by the Institutional Committee on Animal Care, Use and Research of the Bengbu Medical College. Contusive SCI and drug injection. An Infinite Horizon impactor (Precision Systems & Instrumentation) was used to perform contusive SCI, as previously described [19, 20]. The mice were first anesthetized with a cocktail of ketamine (80 mg/kg)/xylazine (10 mg/kg) intraperitoneally injection and then the T9 lamina was excised. The spine was stabilized by clamping the T7 and T11 spinous processes, and then a moderate SCI model was created using a rod (1.3 mm in diameter) with a force of 50 Kdynes. Sham-operated (sham) mice only received a laminectomy without contusive injury. Post-surgically, mice were placed in a temperature-and humidity-controlled chamber. Manual bladder emptying was performed three times daily until reflex bladder emptying was established. To prevent infections, animals were daily provided with chloramphenicol (50 mg/kg) via drinking water. The spinal cord-injured mice were randomly assigned to the vehicle control or CRID3 injection groups. Mice were intraperitoneally injected with 0.01 M PBS (pH 7.4) or CRID3 (Target Molecule Corp., 50 mg/kg prepared in PBS)