Ginkgolide B alleviates cerebral ischemia-reperfusion injury by antagonizing TRIM45 to reduce microglia-mediated neuronal damage

Aim of study: This study investigates the protective effect of GB against cerebral I/R injury and explores its underlying mechanism involving the TRIM45- TAB2-TAK1-TAB1 axis.

Materials and methods: In vivo, a tMCAO rat model was used. Relevant groups were treated with GB, and indicators including neurological function, cerebral infarct volume, and blood-brain barrier (BBB) integrity were detected, with Edaravone as a positive control. In vitro, oxygen-glucose deprivation/reperfusion (OGD/R)-induced BV2 cells were employed. Cell viability, inflammatory response, and protein expression were tested in the cells treated with or without GB. For mechanistic validation, TRIM45 overexpression and TRIM45 knockdown experiments were performed in BV2 cells. Additionally, molecular docking was conducted to predict the binding mode between GB and TRIM45.

Results: GB dose-dependently improved rat neurological function, reduced infarct volume/edema, inhibited Apoptosis, and lowered IL-1β/IL-6/TNF-α levels. Mechanistically, GB downregulated TRIM45 expression, reduced K63-linked ubiquitination of TAB2, disrupted TAB2-TAK1-TAB1 complex formation, and blocked NF-κB pathway activation. Molecular docking revealed that GB directly binds to pocket 279 of TRIM45. Functional studies further confirmed the necessity of TRIM45 in GB's action: TRIM45 overexpression reversed the regulatory effects of GB on TAB2 ubiquitination, inflammatory cytokine production, and NF-κB activation, whereas TRIM45 knockdown mimicked and enhanced GB's anti-inflammatory effects. These gain-of-function and loss-of-function experiments mutually validate that GB exerts its neuroprotective effects against cerebral ischemia-reperfusion injury by targeting the TRIM45-related pathway.

Conclusion: Our findings show that GB protects against cerebral ischemia-reperfusion injury by targeting TRIM45 to disrupt the TRIM45-TAB2-TAK1-TAB1 complex and inhibit NF-κB-mediated neuroinflammation. GB holds potential for treating this injury, warranting further mechanistic studies and clinical trials to support its clinical translation.