Calycosin decreases cerebral ischemia/reperfusion injury by suppressing ACSL4-dependent ferroptosis.

Ischemic stroke is the second leading cause of death globally. Calycosin is a typical phytoestrogen that protects against cerebral ischemia/reperfusion (I/R) injury. However, the role of ferroptosis in this effect remains unknown. In the present study, we investigated the ferroptosis mechanism of calycosin against cerebral I/R injury using transient middle cerebral artery occlusion/reperfusion (tMCAO/R)-exposed rats and oxygen-glucose deprivation/reperfusion (OGD/R)-stimulated PC12 cells. We found that calycosin treatment significantly improved neurological deficits, brain edema, blood-brain barrier (BBB) breakdown, infarction volume, and neuronal injuries in rats that underwent tMCAO/R; similar to ferrostatin-1 (a ferroptosis inhibitor), calycosin prevented cell viability loss in PC12 cells exposed to OGD/R stimulation. In addition, calycosin intervention decreased ferroptosis, as assessed by iron accumulation, malondialdehyde (MDA), superoxide dismutase (SOD), ceramide, and reactive oxygen species (ROS) levels, as well as ferroptosis-related protein expression (ACSL4, TfR1, FTH1, and GPX4). Furthermore, overexpression of ACSL4 reversed calycosin-induced beneficial efficacy in OGD/R-stimulated PC12 cells. The molecular docking analysis demonstrated that calycosin binds to ACSL4 by forming stable hydrogen bonds at G465, K690, and D573. Collectively, these findings indicate that calycosin ameliorates cerebral I/R injury by depressing ACSL4-dependent ferroptosis.

Liu H ，Zhao Z ，Yan M ，Zhang Q ，Jiang T ，Xue J ... -  《-》

Tongqiao Huoxue Decoction inhibits ferroptosis by facilitating ACSL4 ubiquitination degradation for neuroprotection against cerebral ischemia-reperfusion injury.

Cerebral ischemia-reperfusion injury (CIRI) refers to brain tissue injury caused by the temporary interruption of cerebral blood flow ischemia followed by the restoration of reperfusion, which is the main cause of post-stroke brain injury. A traditional Chinese herbal preparation called Tongqiao Huoxue Decoction (TQHX) has shown promise in reducing CIRI in rats. However, the mechanism of this herbal preparation for CIRI remains unclear. This study aimed to evaluate the therapeutic effect of TQHX extract on rats with CIRI and to further explore the underlying mechanisms. The active ingredients of TQHX extract were quantified by the high-performance liquid chromatography (HPLC) condition. We conducted thorough investigations to assess the effects of TQHX on CIRI and ferroptosis using oxygen-glucose deprivation/reperfusion (OGD/R)-treated PC12 cells as an in vitro model and transient middle cerebral artery occlusion (tMCAO) animals as an in vivo model. The neurological score assessment was performed to evaluate the neuroprotective effects of TQHX extract on tMCAO rats. Using histologic methods to study the extent of cerebral infarction, blood-brain barrier, and rat brain tissue. We examined the impact of TQHX on ferroptosis-related markers of Fe2+, superoxide dismutase (SOD), reactive oxygen species (ROS), and malondialdehyde (MDA) in the brain tissue. In addition, the expression of key proteins and markers of ferroptosis, as well as key factors associated with Acyl-CoA synthetase long-chain family member 4 (ACSL4) were detected by Western blot and quantitative real-time PCR (RT-qPCR). TQHX extract could decrease the Longa score and extent of cerebral infarction of tMCAO rats, which exerted the function of neuroprotection. Additionally, TQHX treatment efficiently decreased levels of MDA and ROS while increasing the expression of SOD and ferroptosis-related proteins including ferritin heavy chain 1 (FTH1) and glutathione peroxidase 4 (GPX4) at the transcription and translation level. Meanwhile, TQHX provided strong protection against oxidative stress and ferritin accumulation by increasing the ubiquitination and degradation of ACSL4. The injection of OE-ACSL4 reversed the effects of TQHX on neuroprotection and ferroptosis inhibition in PC12 cells. The injection of shACSL4 reversely validate the crucial role of ACSL4 in CIRI rat treatment. This work shows that TQHX promotes the ubiquitination-mediated degradation of ACSL4, which improves oxidative stress and inhibits the beginning of ferroptosis in cells. TQHX provides a possible path for additional research in CIRI therapies, advancing translational investigations.

Ou Z ，Deng Y ，Wu Y ，Wang Y ，Zhao Y ，Liu C ，Wang Z ，Liu M ，Hu X ，Fang L ，Chen J ... -  《-》

Ginkgolide B attenuates cerebral ischemia-reperfusion injury via inhibition of ferroptosis through disrupting NCOA4-FTH1 interaction.

Cerebral ischemia/reperfusion (I/R) injury is a major cause of neuronal damage and death. Ginkgolide B (GB) has been shown to exhibit neuroprotective effects in various brain injury models. The aim of study was to investigate the potential role of GB in protecting against cerebral I/R injury and explore the underlying mechanisms. Adult male Sprague-Dawley rats were exposed to transient middle cerebral artery occlusion (tMCAO) followed by reperfusion in order to trigger cerebral I/R injury. The rats were treated with different doses of GB, vehicle control or positive drug. Neurological function, infarct volume, and levels of ferroptosis markers were evaluated. In vitro experiments were performed using OGD/R-induced PC12 cells to further investigate the effects of GB on ferroptosis and its mechanisms. In addition, molecular docking, and microscale thermophoresis (MST) assay were conducted to explore the combination of GB and NCOA4. Reduced infarct volume and enhanced neurological function were signs of dose-dependent protection from cerebral I/R injury by GB therapy. Additionally, GB treatment had an impact on the levels of oxidative stress and ferroptosis markers, including reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and Fe2+ in the cerebral environment during IR injury. Moreover, relevant ferroptosis key factors such as ACSL4, GPX4, FTH1, and NCOA4 can be regulated by GB. In OGD/R-induced PC12 cells, GB protected against ferroptosis by inhibiting autophagy and disrupting the interaction of NCOA4-FTH1. Our findings suggest that GB may protect against cerebral I/R injury by inhibiting ferroptosis through disrupting NCOA4-FTH1 interaction. GB has potential therapeutic applications for cerebral I/R injury, and further investigation of the underlying mechanisms and clinical trials are warranted.

Yang Y ，Wu Q ，Shan X ，Zhou H ，Wang J ，Hu Y ，Chen J ，Lv Z ... -  《-》

Rhein attenuates cerebral ischemia-reperfusion injury via inhibition of ferroptosis through NRF2/SLC7A11/GPX4 pathway.

Liu H ，Zhang TA ，Zhang WY ，Huang SR ，Hu Y ，Sun J ... -  《-》

Baicalein ameliorates cerebral ischemia-reperfusion injury by inhibiting ferroptosis via regulating GPX4/ACSL4/ACSL3 axis.

Accumulating evidence have indicated that ferroptosis plays a crucial role in cerebral ischemia-reperfusion (I/R) injury which is the most serious treatment complication of ischemic stroke. Baicalein (5,6,7-trihydroxyflavone) is a main bioactive ingredient isolated from a traditional Chinese medicine named Baikal Skullcap, which is the root of Scutellaria baicalensis Georgi. This study investigated the potential role of baicalein in cerebral I/R injury using oxygen-glucose deprivation and reoxygenation (OGD/R) HT22 cells, transient middle cerebral artery occlusion (tMCAO) mice and RSL3-sitmulated HT22 cells. Baicalein improved the viability of OGD/R cells and significantly ameliorated cerebral I/R injury in tMCAO mice. Baicalein decreased the iron levels, lipid peroxidation production and morphology features of ferroptosis of the brain tissues in tMCAO mice, which indicated that baicalein ameliorated cerebral I/R injury by inhibiting ferroptosis in vivo and in vitro. We further confirmed that baicalein had the activity of inhibiting ferroptosis in RSL3-stimulated HT22 cells. Western blot revealed that baicalein inhibited the ferroptosis by regulating on the expression levels of GPX4, ACSL4 and ACSL3 in OGD/R cells, tMCAO mice and RSL3-stimulated HT22 cells. Our findings demonstrated that baicalein reversed the cerebral I/R injury via anti-ferroptosis, which was regulated by GPX4/ACSL4/ACSL3 axis. The results suggested that baicalein has therapeutic potential as a drug for cerebral I/R injury.

Li M ，Meng Z ，Yu S ，Li J ，Wang Y ，Yang W ，Wu H ... -  《-》