Icariside II attenuates cerebral ischemia/reperfusion-induced blood-brain barrier dysfunction in rats via regulating the balance of MMP9/TIMP1.

Cerebral ischemia/reperfusion (I/R) results in harmful consequences during ischemic stroke, especially the disruption of the blood-brain barrier (BBB), which leads to severe hemorrhagic transformation through aggravation of edema and brain hemorrhage. Our previous study demonstrated that icariside II (ICS II), which is derived from Herba Epimedii, attenuates cerebral I/R injury by inhibiting the GSK-3ß-mediated activation of autophagy both in vitro and in vivo. However, the effect of ICS II on the BBB remains unclear. Thus, in this study, we investigated the regulation of BBB integrity by ICS II after cerebral I/R injury and further explored the underlying mechanism in rats. Cerebral I/R injury was induced by middle cerebral artery occlusion (MCAO), and the treatment groups were administered ICS II at a dose of 16 mg/kg by gavage twice a day for 3 days. The results showed that ICS II effectively prevented BBB disruption, as evidenced by Evans Blue staining. Moreover, ICS II not only significantly reduced the expression of MMP2/9 but also increased TIMP1 and tight junction protein (occludin, claudin 5, and ZO 1) expression. Intriguingly, ICS II may directly bind to both MMP2 and MMP9, as evidenced by molecular docking. In addition, ICS II also inhibited cerebral I/R-induced apoptosis and ameliorated the Bax/Bcl-2 ratio and cleaved-caspase 3 level. Collectively, our findings reveal that ICS II significantly ameliorates I/R-induced BBB disruption and neuronal apoptosis in MCAO rats by regulating the MMP9/TIMP1 balance and inhibiting the caspase 3-dependent apoptosis pathway.

Electroacupuncture Inhibits Ferroptosis Induced by Cerebral Ischemiareperfusion.

BACKGROUND: Electroacupuncture (EA) treatment has been recommended by World Health Organization (WHO) for years on cerebral ischemia treatment, but the specific mechanism is still elusive. Studies have shown that EA can relieve brain damage after ischemic stroke by inhibiting programmed cell death (PCD), such as apoptosis, necroptosis, and autophagy. Ferroptosis, a unique form of cell death, has been highlighted recently and found to occur in I/R injury. We, therefore, investigated whether EA plays an essential role in relieving cerebral I/R injury via ferroptosis. METHODS: The modified MCAO/R rats model was established and then divided into four groups with or without EA treatment. Neurological deficit score and TTC staining were used to evaluate the neurological deficit and infarct volume of each group. Transmission electron microscope (TEM) and immunofluorescence staining were applied for mitochondrial ultrastructure and ROS accumulation observation, respectively. The proteins and mRNA expression of ACSL4, TFR1, and GPX4 were assessed by western blot and qPCR to detect the progress of ferroptosis. RESULTS: EA treatment improved neurological deficits and reduced infarct volume. Moreover, EA significantly relieved the mitochondrial morphological changes and inhibited ROS Production in MCAO rats. In terms of its mechanism, EA obviously decreased the ACSL4 and TFR1 expressions and promoted GPX4 levels in MCAO/R model rats. CONCLUSION: These findings indicate that EA might play an essential role in relieving cerebral I/R injury via ferroptosis.

Bone Marrow Mesenchymal Stem Cell Exosomal miR-345-3p Ameliorates Cerebral Ischemia-reperfusion Injury by Targeting TRAF6.

INTRODUCTION: The purpose of this study was to investigate the effects of bone marrow mesenchymal stem cells (BMSCs) exosomal miR-345-3p and tumor necrosis factor receptorassociated factor 6 (TRAF6) on cerebral ischemia reperfusion (CIR) injury. Exosomes (Exos) derived from BMSCs were isolated and identified. PC12 (rat pheochromocytoma) cells were used to establish an oxygen and glucose deprivation/reoxygenation (OGD/R) model. METHODS: Cell counting kit-8, TUNEL staining, lactate dehydrogenase staining, RT-qPCR, and western blotting were utilized for analyzing the functions of miR-345-3p about PC12 cells. Dualluciferase reporter experiment was then to confirm the link between miR-345-3p and TRAF6. Finally, using male SD rats, the middle cerebral artery occlusion (MCAO) model was constructed. Regulation of I/R damage in MCAO rats of miR-345-3p and TRAF6 were further explored in the changes of modified neurological severity score, cerebral infarction pictures, relative infarct volume, and histopathological changes. After OGD/R treatment, neuronal apoptosis was dramatically increased. After treatment with exosomal miR-345-3p, OGD/R-induced neuroapoptosis was dramatically inhibited. Exosomal miR-345-3p inhibited OGD/R-induced neuroapoptosis by downregulating the expression of TRAF6. However, the miR-345-3p inhibitor aggravated the changes caused by OGD/R. RESULTS: The corresponding regulations of miR-345-3p were reversed with TRAF6 overexpression. The animal experiments in vivo further verified that miR-345-3p ameliorated brain I/R injury in MCAO rats by targeting TRAF6. CONCLUSION: This study found that BMSCs-exosomal miR-345-3p protected against CIR injury by decreasing TRAF6.

Electroacupunture contributes to recovery of neurological deficits in experimental stroke by activating astrocytes.

BACKGROUND: Neurological deficits is one of the most prevalent clinical manifestation after stroke. The effects of astrocytes activated by electroacupunture (EA) after stroke on the neurological recovery in middle cerebral artery occlusion (MCAO) rats was not clear and definite. OBJECTIVE: Our previous study showed that treatment with EA for 7 days contributed to the activation of astrocytes in MCAO rats. The purposes of this study were to 1) confirm the effects of EA for 14 days on activation of astrocytes in MCAO rats, and 2) test the relationships between activation of astrocytes and neurological functional recovery induced by EA in MCAO rats. METHODS: All rats were randomly divided into five groups: naïve control group, sham control control group, MCAO, MCAO/EAn, MCAO/EAd (n = 8, for each group). Rats in MCAO/EAn group received EA treatment at acupoints of Neiguan (PC06). MCAO/EAd group received EA stimulus at acupoints of Diji (SP08). The primary indicators were locomotor recovery, histopathology, immunohistochemistry, RT-PCR and Western blot. RESULTS: The neurological deficit and histopathological improvements and activation of astrocytes were observed after EA treatment at acupoints PC06. Parametric correlation analyses revealed a cubic correlation relationship between activation of astrocytes and neurological recovery of MCAO rats treated with EA. CONCLUSION: EA treatment at the acupoints of Neiguan involved in the regulation of activation of astrocytes, which our data suggested has a cubic correlation relationship with the neurological recovery of MCAO rats.