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Mitochondrial dysfunction and excessive reactive oxygen species production due to impaired mitochondrial biogenesis have been proven to exacerbate secondary brain injury after intracerebral hemorrhage (ICH). The G-protein-coupled receptor 39 (GPR39) agonist TC-G 1008 has been shown to exert anti-oxidative stress effect in acute hypoxic brain injury. Herein, our study aimed to investigate the potential effects of TC-G 1008 on neuronal mitochondrial biogenesis and antioxidative stress in a mouse model of ICH and explore the underlying mechanisms. A total of 335 male C57/BL6 mice were used to establish an autologous blood-induced ICH model. Three different dosages of TC-G 1008 were administered via oral gavage at 1 h, 25 h, and 49 h post-ICH. The GPR39 siRNA and cAMP response element-binding protein (CREB) inhibitor 666-15 were administered via intracerebroventricular injection before ICH insult to explore the underlying mechanisms. Neurobehavioral function tests, Western blot, quantitative polymerase chain reaction, immunofluorescence staining, Fluoro-Jade C staining, TUNEL staining, dihydroethidium staining, transmission electron microscopy, and enzyme-linked immunosorbent assay were performed. Expression of endogenous GPR39 gradually increased in a time-dependent manner in the peri-hematoma tissues, peaking between 24 and 72 h after ICH. Treatment with TC-G 1008 significantly attenuated brain edema, hematoma size, neuronal degeneration, and neuronal death, as well as improved neurobehavioral deficits at 72 h after ICH. Moreover, TC-G 1008 upregulated the expression of mitochondrial biogenesis-related molecules, including PGC-1α, NRF1, TFAM, and mitochondrial DNA copy number, associated with antioxidative stress markers, such as Nrf2, HO-1, NQO1, SOD, CAT, and GSH-Px. Furthermore, treatment with TC-G 1008 preserved neuronal mitochondrial function and structure post-ICH. Mechanistically, the protective effects of TC-G 1008 on neuronal mitochondrial biogenesis and antioxidative stress were partially reversed by GPR39 siRNA or 666 -15. Our findings indicated that GPR39 agonist TC-G 1008 promoted mitochondrial biogenesis and improved antioxidative capability after ICH, partly through the CREB/PGC-1α signaling pathway. TC-G 1008 may be a potential therapeutic agent for patients with ICH., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Pyroptosis has been proven to be responsible for secondary brain injury after intracerebral hemorrhage (ICH). A recent study reported that Raf kinase inhibitor protein (RKIP) inhibited assembly and activation of inflammasome in macrophages. Our present study aimed to investigate the effects of RKIP on inflammasome-mediated neuronal pyroptosis and underlying neuroprotective mechanisms in experimental ICH. Here, we showed that RKIP expression was decreased both in cerebrospinal fluid (CSF) samples from patients with ICH and in the peri-hematoma tissues after experimental ICH. In mouse ICH model, activation of RKIP remarkably improved neurological deficits, reduced brain water content and BBB disruption, and promoted hematoma absorption at 24 h after ICH, as well as alleviated neuronal degeneration, reduced membrane pore formation, and downregulated pyroptotic molecules NLRP3, caspase-1 P20, GSDMD-N, and mature IL-1β. Besides, RKIP activation decreased the number of caspase-1 P20-positive neurons after ICH. However, RKIP inhibitor reserved the neuroprotective effects of RKIP at 24 h following ICH. Moreover, RKIP could bind with ASC, then interrupt the assembly of NLRP3 inflammasome. Mechanistically, inhibiting the caspase-1 by VX-765 attenuated brain injury and suppressed neuronal pyroptosis after RKIP inhibitor-pretreated ICH. In conclusion, our findings indicated that activation of RKIP could attenuate neuronal pyroptosis and brain injury after ICH, to some extent, through ASC/Caspase-1/GSDMD pathway. Thus, RKIP may be a potential target to attenuate brain injury via its anti-pyroptosis effect after ICH., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

We previously found that hematoma worsens hydrocephalus after intraventricular hemorrhage (IVH) via increasing iron deposition and aggravating ependymal cilia injury; therefore, promoting hematoma absorption may be a promising strategy for IVH. Recently, some investigations imply that simvastatin has the ability of accelerating hematoma absorption. Thus, this study was designed to examine the efficacy of simvastatin for IVH in rats. Intracerebral hemorrhage with ventricular extension was induced in adult male Sprague-Dawley rats after autologous blood injection. Simvastatin or vehicle was administered orally at 1 day after IVH and then daily for 1 week. MRI studies were performed to measure the volumes of intracranial hematoma and lateral ventricle at days 1, 3, 7, 14, and 28 after IVH. Motor and neurocognitive functions were assessed at days 1 to 7 and 23 to 28, respectively. Iron deposition, iron-related protein expression, ependymal damage, and histology were detected at day 28. Expression of CD36 scavenger receptor (facilitating phagocytosis) was examined at day 3 after IVH using western blotting and immunofluorescence. Simvastatin significantly increased hematoma absorption ratio, reduced ventricular volume, and attenuated neurological dysfunction post-IVH. In addition, less iron accumulation and more cilia survival was observed in the simvastatin group when compared with the control. What's more, higher expression of CD36 was detected around the hematoma after simvastatin administration. Simvastatin significantly enhanced brain hematoma absorption, alleviated hydrocephalus, and improved neurological recovery after experimental IVH, which may in part by upregulating CD36 expression. Our data suggest that early simvastatin use may be a novel therapy for IVH patients.

Brain edema following intracerebral hemorrhage (ICH) causes severe secondary brain injury, and no efficient pharmacological preventions are available. The present study was designed to demonstrate the neuroprotective effects of glibenclamide on brain edema and key factors of the blood-brain barrier (BBB). The study was divided into two parts. First, we utilized an autoblood-induced rat model to investigate the expression of sulfonylurea receptor 1 (Sur1). Second, rats were randomized into sham, vehicle, and glibenclamide groups. Neurological scores, brain water content, Evans blue extravasation, Morris water maze test, western blots, and immunofluorescence were used to study the effects of glibenclamide. The expression of the Sur1-Trpm4 channel but not the Sur1-KATP channel was increased in the perihematomal tissue following ICH. Glibenclamide administration significantly decreased the brain water content, restored the BBB, and reduced the expression of MMPs. In addition, glibenclamide improved long-term cognitive deficits following ICH. Glibenclamide protected BBB integrity and improved neurological outcomes after ICH by inhibiting the Sur1-Trpm4 channel, which reduces the expression of MMPs and thereby increases BBB tight-junction protein levels. Glibenclamide may have potential to protect the BBB after ICH.

Germinal matrix hemorrhage (GMH) is defined as the rupture of immature blood vessels in the subependymal zone of premature infants with significant mortality and morbidity. Considering the notable social and ecological stress brought by GMH-induced brain injury and sequelae, safe and efficient pharmacological preventions are badly needed. Currently, several appropriate animal models are available to mimic the clinical outcomes of GMH in human patients. In the long run, hemorrhagic strokes are the research target. Previously, we found that minocycline was efficient to alleviate GMH-induced brain edema and posthemorrhagic hydrocephalus (PHH) in rats, which may be closely related to the activation of cannabinoid receptor 2 (CB2R). However, how the two molecules correlate and the underlined molecular pathway remain unknown. To extensively understand current experimental GMH treatment, this literature review critically evaluates existing therapeutic strategies, potential treatments, and potentially involved molecular mechanisms. Each strategy has its own advantages and disadvantages. Some of the mechanisms are still controversial, requiring an increasing number of animal experiments before the therapeutic strategy would be widely accepted.

Thrombin mediates the life-threatening cerebral edema and blood-brain barrier (BBB) damage that occurs after intracerebral hemorrhage (ICH). We previously found that the selective cannabinoid receptor 2 (CB2R) agonist JWH-133 reduced brain edema and neurological deficits following germinal matrix hemorrhage (GMH). We explored whether CB2R stimulation ameliorated thrombin-induced brain edema and BBB permeability as well as the possible molecular mechanism involved. A total of 144 Sprague-Dawley (S-D) rats received a thrombin (20 U) injection in the right basal ganglia. JWH-133 (1.5 mg/kg) or SR-144528 (3.0 mg/kg) and vehicle were intraperitoneally (i.p.) injected 1 h after surgery. Brain water content measurement, Evans blue (EB) extravasation, Western blot, and immunofluorescence were used to study the effects of a CB2R agonist 24 h after surgery. The results demonstrated that JWH-133 administration significantly decreased thrombin-induced brain edema and reduced the number of Iba-1-positive microglia. JWH-133 also decreased the number of P44/P42(+)/Iba-1(+) microglia, lowered Evans blue extravasation, and inhibited the elevated matrix metallopeptidase (MMP)-9 and matrix metallopeptidase (MMP)-12 activities. However, a selective CB2R antagonist (SR-144528) reversed these effects. We demonstrated that CB2R stimulation reduced thrombin-induced brain edema and alleviated BBB damage. We also found that matrix metalloproteinase suppression may be partially involved in these processes.

Primary spontaneous intracerebral hemorrhage (ICH) with secondary intraventricular hemorrhage (IVH) is an important clinical problem of which little is known. IVH and hydrocephalus are independent predictors of poor outcome in ICH. The aims of this study were, therefore, to establish a rat model of ICH with ventricular extension and investigate the occurrence of post-hemorrhagic chronic hydrocephalus and perihematomal tissue injury. Based on our previous rat model of IVH, we adjusted the injection coordinates and 200 μl autologous blood was stereotaxically infused into the right striatum (coordinates: 0.2 mm posterior, 2.2 mm lateral, and 5.0 mm depth to the bregma). At 24 h post-infusion, the rats produced reproducible hematoma and ventricle expansion, which closely mimics the ICH with ventricular extension in humans. Hematoma consequences and perihematomal tissue injury were evaluated on the acute phase. At 4 weeks, ventricular dilatation, brain tissue loss, hippocampus volume, and cortical thickness were measured with magnetic resonance imaging and neurocognitive function was assessed using the Morris water maze test. With blood infusion, the animals demonstrated brain edema, blood-brain barrier breakdown, and marked perihematomal tissue injury on the acute phase. At 4 weeks, the T2 images showed remarkable hydrocephalus and tissue loss, and the Morris water maze test revealed neurocognitive deficits. The present ICH with the ventricular extension rat model features characteristics of both ICH and IVH rat models, which could be used for extending our pathophysiological understanding of post-hemorrhagic chronic hydrocephalus and perihematomal tissue damage.