The protective mechanism of Hydroxysafflor yellow A for the treatment of stroke - heart - syndrome via activating the ZBP1-NLRP3 signaling pathway

Background

Hydroxysafflor yellow A (HSYA), the primary active constituent of Safflower, a traditional Chinese medicine, has demonstrated promising therapeutic potential in the treatment of cardiovascular and cerebrovascular injuries. However, the impact of HSYA on stroke-induced cardiac syndrome and the underlying mechanisms remain to be elucidated.

Methods

Laser super-resolution microscopy and transmission electron microscopy were employed to examine cerebral ischemic injury. Echocardiography and immunofluorescence techniques were utilized to assess cardiac function and inflammatory damage. Western blot analysis was conducted to measure the expression levels of apoptosis-related proteins in heart tissue.

Results

HE revealed that SHS induced inflammatory infiltration in the myocardium. Echocardiographic findings indicated that SHS impaired cardiac function. ELISA results demonstrated that SHS led to elevated levels of norepinephrine and epinephrine. Transmission electron microscopy (TEM) observations confirmed that SHS resulted in mitochondrial damage within cardiac cells. Immunofluorescence analysis further showed that SHS facilitated the recruitment of cardiac macrophages, upregulated the expression of ZBP1 and NLRP3, and increased the production of inflammatory cytokines and inflammasomes. Co-immunoprecipitation experiments demonstrated that ZBP1 interacts with NLRP3. Inhibiting sympathetic overactivation exerts a protective effect on the heart. Furthermore, HSYA not only reversed the aforementioned conditions but also exerted protective effects on both cardiac and cerebral tissues. Immunofluorescence analysis revealed that HSYA inhibited the formation of the ZBP1 and NLRP3 complexes, as well as the inflammasome complex. Molecular docking studies indicated that HSYA and ZBP1 share the LYS-166 binding site, and protein docking results demonstrated that ZBP1 and NLRP3 also share this binding site. Mutations at this site diminished the protective efficacy of HSYA against SHS.

Conclusions

HSYA mitigates macrophage recruitment through the inhibition of the ZBP1-NLRP3 signaling pathway, thereby improving sympathetic nerve function, suppressing panoptosis, and alleviating SHS injury by competitively binding to the LYS-166 site of ZBP1 with NLRP3.