Rapamycin mitigates gas explosion-induced spleen injury in rats via mechanistic target of rapamycin (mTOR) signaling pathway

Gas explosion is a recurrent event in coal mining that cause severe spleen damage due to shockwaves, which has no effective treatment. This study aimed to explore the regulatory role of autophagy in gas explosion-induced blast spleen injuries in rats. 120 Sprague-Dawley male rats were randomly divided into 4 groups, including normal control (NC), gas explosion-induced spleen injury (Model, M), autophagy inhibitor 3-methyladenine group (M+3-MA), and induction Rapamycin (RAPA) group (M+RAPA) groups. After explosion, the inhibitor group and induction group rats were immediately given intraperitoneal injection of 3-MA (15 mg/kg)/ RAPA (1 mg/kg). The rats were anesthetized and the spleen were obtained at 24 h, 72 h, and 7 days. The results showed that gas explosion reduced the spleen index, induced spleen blooding, infiltration of inflammatory cells, and increased autophagosomes. The expression of Lc3-Ⅱ was increased, whereas p62 and p-mTOR was decreased significantly (P<0.05) in model group. Compared with the model group, RAPA improved the spleen index, spleen bleeding, inflammation, and autophagosomes significantly. The expression of Lc3-Ⅱ was increased, p62 and p-mTOR was decreased significantly, but the opposite results were observed in the inhibitor group. Taken together, we firstly found that RAPA can mitigate gas explosion-induced spleen injury via mTOR signaling, which provides a new idea for the treatment of spleen injury including but not limited to coal mine accidents.