Figure 4: Lithium inhibits pyroptosis in the spinal cord of rats with SCI. Sham group: no spinal cord injury or treatment; SCI group: spinal cord injury only; LiCl group: lithium treatment after spinal cord injury. (A) Representative images of immunohistochemistry staining for Caspase-1 7 days after surgery. The number of Caspase-1–positive cells was higher in the LiCl group than in the sham group, but lower than in the SCI group. Black arrows indicate Caspase-1–positive neurons. Scale bars: 50 μm. (B) Quantitation of Caspase-1–positive cells per 1 mm2 7 days after injury. (C) NLRP3, ASC, pro-Caspase-1, Caspase-1, GSDMD, and IL-18 expression in the spinal cord. (D) Quantification of NLRP3, ASC, pro-Caspase-1, Caspase-1, GSDMD, and IL-18 expression in the spinal cord. Data are shown as mean ± SD (n = 6). *P < 0.05, vs. sham group; #P < 0.05, vs. SCI group (one-way analysis of variance followed by the least significant difference test). ASC: Apoptosi-associated speck-like protein; GSDMD: gasdermin-d; IL-18: interleukin-18; LiCl: lithium chloride; NLRP3: NOD-like receptors 3; SCI: spinal cord injury.