CLEC5A Promotes Neuronal Pyroptosis in Rat Spinal Cord Injury Models by Interacting with TREM1 and Elevating NLRC4 Expression.

Pyroptosis, an inflammatory Programmed cell death, has recently been found to play an important role in spinal cord injury (SCI). C-type lectin domain family 5 member A (CLEC5A), triggering receptor expressed on myeloid cells 1 (TREM1), and NLR-family CARD-containing protein 4 (NLRC4) have been reported to be associated with neuronal pyroptosis, but few studies have clarified their functions and regulatory mechanisms in SCI. In this study, CLEC5A, TREM1, and NLRC4 were highly expressed in lidocaine-induced SCI rat models, and their knockdown alleviated lidocaine-induced SCI. The elevation of proptosis related indicators LDH, ASC, GSDMD-N, IL-18, caspase-1, and IL-1β levels in SCI rats was attenuated after silencing of CLEC5A, TREM1, or NLRC4. Lidocaine-induced the decrease in cell viability and the elevation in cell death were partly reversed after CLEC5A, TREM1, or NLRC4 silencing. Lidocaine-mediated effects on the levels of LDH, ASC, GSDMD-N, IL-18, caspase-1, and IL-1β in lidocaine-induced PC-12 cells were weakened by downregulating CLEC5A, TREM1, or NLRC4. CLEC5A could interact with TREM1 to mediate NLRC4 expression, thus accelerating neuronal pyroptosis, ultimately leading to SCI exacerbation. In conclusions, CLEC5A interacted with TREM1 to increase NLRC4 expression, thus promoting neuronal pyroptosis in rat SCI models, providing new insights into the role of neuronal pyroptosis in SCI.Significance statement Pyroptosis has been reported to be involved in SCI. Higher levels of CLEC5A, TREM1, and NLRC4 associated with neuronal pyroptosis. However, the role and regulatory mechanism of CLEC5A, TREM1, and NLRC4 in SCI were not clear. Here, high expression of CLEC5A, TREM1, and NLRC4 was observed in lidocaine-induced SCI rat models. CLEC5A could interact with TREM1 to enhance the expression of NLRC4, thus accelerating neuronal pyroptosis in rat SCI models. These findings identify CLEC5A, TREM1, and NLRC4 as potential therapeutic targets for SCI.