Tong-Qiao-Huo-Xue Decoction mitigates post-stroke inflammatory response via suppression of the FIB-NLRP3 signaling pathway

Abstract

The post-stroke inflammatory response denotes the inflammatory damage inflicted upon brain tissue following stroke. Plasma fibrinogen (FIB) can permeate the compromised blood-brain barrier (BBB) after ischemic stroke, leading to the activation of the NLRP3 inflammasome. Tong-Qiao-Huo-Xue-Decoction (TQHXD), a traditional formula used to promote blood circulation and resolve blood stasis, has shown potential in this context. Nevertheless, the precise therapeutic mechanisms of TQHXD in mitigating cerebral ischemia-reperfusion injury remain to be fully elucidated. Objective. To examine the reparative effects and underlying mechanisms of TQHXD-CSF on inflammatory damage in BV-2 cells subjected to oxygen and glucose deprivation/reoxygenation (OGD/R) injury. Methods. To establish an in vitro model of OGD/R injury and an inflammatory BV-2 cells model induced by FIB. The protective effects of TQHXD-CSF on OGD/R-injured cells were verified using CCK-8 and LDH assays. Immunofluorescence, SEM, Western blotting, and CHIP-PCR were employed to confirm that TQHXD reduces the inflammatory response by downregulating FIB levels. Pull-down and co-immunoprecipitation (CO-IP) assays were conducted to detect the interaction between FIB and NLRP3. Results. TQHXD-CSF can significantly inhibit the abnormal increase in LDH levels induced by OGD/R, enhance cell viability, and mitigate cell pyroptosis. Additionally, TQHXD-CSF reversed the marked upregulation of FIB, NLRP3, and GSDMD fluorescence intensity and protein expression caused by the FIB inflammation model, demonstrating an effect comparable to that of lumbrokinase, a fibrinolytic agent for FIB. Furthermore, it notably reduced the acetylation of H3 and H4 in the NLRP3 promoter. Importantly, the pull-down and CO-IP results indicated a robust binding affinity between FIB and NLRP3. Conclusion. TQHXD-CSF can inhibit inflammation by downregulating the FIB-NLRP3 pathway and exert a protective effect on BV-2 cells under OGD/R and FIB inflammatory injury.

Keywords: Fibrinogen; Inflammatory; NLRP3; Pyroptosis; Tong-Qiao-Huo-Xue-Decoction.