The Inhibition of Spinal Astrocytic JAK2-STAT3 Pathway Activation Correlates with the Analgesic Effects of Triptolide in the Rat Neuropathic Pain Model

Figure 3

The effects of intrathecal triptolide (10 μg/kg) on SNL-induced GFAP and pSTAT3 in the SDH of the rat by double-immunofluorescence microphotographs on POD 6. The Sham surgery induced weak p-STAT3 and GFAP-immunoreactivity (-IR) in the ipsilateral dorsal spinal cord (A, A′, and A′′). Changes in GFAP-IR and p-STAT3-IR were not observed in the Sham group after intrathecal triptolide application (B, B′, and B′′). After SNL surgery, increased GFAP-IR and p-STAT3-IR were detected ipsilateral to the lesion of the SDH, and many of the p-STAT3-IRs were colabelled with GFAP-IR, indicating that p-STAT3 accumulated in spinal cord astrocytes on POD 6 (C, C′, and C′′). The intrathecal administration of triptolide inhibited the expression of GFAP- and p-STAT3-IR in the ipsilateral SDH after SNL (D, D′, and D′′). SNL, spinal nerve ligation; POD, postoperative day, SDH, spinal dorsal horn. Scale bar, 100 μm.