Electroacupuncture extends the time window of thrombolytic therapy in rats by reducing disruptions of blood–brain barrier and inhibiting GSDMD-mediated pyroptosis

Abstract

Objective

Thrombolytic therapy is the primary treatment for acute ischemic stroke. Extending the therapeutic time window can effectively reduce the harmful side effects associated with thrombolytic therapy. Although electroacupuncture (EA) has been shown to extend this time window, the specific mechanisms remain unclear.

Methods

We developed an embolic stroke model in rats and administered EA during thrombolytic therapy with recombinant tissue plasminogen activator (rt-PA) either 4.5 or 6 h after stroke onset. Neurological deficits were evaluated at 2 and 24 h post-stroke. Brain tissue was collected for analysis using 2,3,5-triphenyl tetrazolium chloride (TTC) staining, water content measurement, blood–brain barrier (BBB) permeability assessment, electron microscopy, and TUNEL assay. Immunofluorescence staining, western blotting, and enzyme-linked immunosorbent assays were employed to quantify the expression of proteins related to BBB integrity and pyroptosis.

Results

Neuronal damage and BBB disruption along with increased expression of pyroptosis-related proteins were observed following thrombolytic therapy at the 6-hour mark. EA treatment improved neurological outcomes, reduced infarct volume, and alleviated BBB disruption. EA also inhibited the expression of matrix metalloproteinase 9 (MMP9) and enhanced the expression of tissue inhibitor of metalloproteinases 1 (TIMP1), helping to maintain BBB integrity. Furthermore, EA reduced the expression of pyroptosis-related proteins, including gasdermin D (GSDMD), interleukin-1β (IL-1β), and interleukin-18 (IL-18). EA also reduced the co-expression of GSDMD and MMP9 in brain tissues.

Conclusions

EA may be a promising therapeutic approach for extending the thrombolytic therapy window by protecting the BBB and inhibiting GSDMD-mediated pyroptosis.