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To investigate the protective effects of dexmedetomidine on cerebral ischemia-reperfusion injury through the activation of the brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) signaling pathway. This study utilized hippocampal neuronal oxygen-glucose deprivation/reoxygenation (OGD/R) models and rat middle cerebral artery occlusion models, with dexmedetomidine intervention. Compared with the sham-operated group, the model group rats exhibited a significant increase in Zea-Longa scores, a marked prolongation of the escape latency, a notable reduction in the number of platform crossings, a significant increase in the percentage of cerebral infarct size, and a marked decrease in the expression of BDNF, TrkB, and Bcl-2 proteins and mRNA (P < 0.05). The dexmedetomidine group showed significantly better outcomes in all above parameters compared to the model group. Compared with the control group, the OGD/R group exhibited a reduction in hippocampal neuronal cell viability, a significant increase in apoptosis rate, elevated expression of Bax and C-caspase-3 proteins, a marked decrease in Bcl-2 protein levels, and a significant reduction in the expression of BDNF and TrkB proteins and mRNA (P < 0.05). Dexmedetomidine exerts significant neuroprotective effects by activating the BDNF/TrkB signaling pathway, thereby alleviating ischemic brain injury. Show less

To investigate the effect of pterostilbene (PTE), a natural dimethyl ether analog of resveratrol with higher bioavailability, on cognitive recovery after cerebral ischemia reperfusion (IR) injury and its potential mechanisms. Mice were subjected to middle cerebral artery occlusion and assigned to Sham, IR, PTE+IR, and PTE+Zinc Protoporphyrin (ZnPP)+IR groups. Cognitive function was assessed using the Morris water maze. Cerebral infarct volume was evaluated by 2,3,5-triphenyltetrazolium chloride (TTC) staining, and neuronal apoptosis was determined via TUNEL assay. The protein levels of postsynaptic density protein 95 (PSD-95), phosphorylated cAMP response element-binding protein (p-CREB), brain-derived neurotrophic factor (BDNF), and histone deacetylases (HDACs) in the hippocampus were measured by western blot. PTE treatment significantly reduced cerebral infarct volume, alleviated cognitive deficits, and inhibited neuronal apoptosis in the hippocampus. At the molecular level, PTE up-regulated the expression of PSD-95, p-CREB, and BDNF, while down-regulating HDAC (1, 2, 3, 4, 7) levels. The beneficial effects of PTE were partially reversed by the HO-1 inhibitor ZnPP. PTE ameliorates cognitive impairment induced by cerebral IR injury, potentially through activating the BDNF/CREB pathway and inhibiting HDAC expression. This suggests PTE as a promising neuroprotective agent for post-stroke cognitive recovery. Show less

Children who experience cardiac arrest often suffer lasting neurological deficits, including impairments to learning and memory, due to global cerebral ischemia (GCI). Using a juvenile mouse model of cardiac arrest and resuscitation, we investigated the long-term effects of GCI and potential therapeutic interventions. Following juvenile GCI, long-term potentiation (LTP) and memory were impaired for several weeks followed by endogenous recovery coinciding with changes in brain-derived neurotrophic factor (BDNF) levels, an essential regulator of synaptic plasticity specifically in juveniles but not adults. Given that BDNF is unstable in plasma and cannot cross the blood-brain barrier, we explored the use of type II ampakines, positive allosteric modulators of AMPA receptors, to increase BDNF protein levels in the brain. In vivo administration of type II ampakines 14 days after GCI increased hippocampal BDNF levels, restored LTP, and improved hippocampal-dependent memory and learning behavior. These findings highlight the potential of type II ampakines as an innovative therapeutic intervention to restore synaptic and cognitive function at delayed time points after juvenile GCI. Show less

Post-stroke neurogenic bladder dysfunction impairs patients' quality of life, yet current treatments offer limited effectiveness. This study investigated the therapeutic effects and underlying mechanisms of human amniotic fluid stem cell-derived extracellular vesicle (hAFSC-EV) on bladder dysfunction and neurovascular plasticity after cerebral ischemia. Thirty-six female rats underwent bilateral ovariectomy and were assigned to sham-operated or 90-min middle cerebral artery occlusion (MCAO) groups, with or without a single injection of hAFSC-EVs. Magnetic resonance imaging (MRI), cystometry, blood-brain barrier (BBB) permeability, and markers of neurogenesis and angiogenesis in ischemic brain were assessed. Bladder levels of brain-derived neurotrophic factor (BDNF), β3-adrenoceptor, adenylate cyclase, and M2- and M3-muscarinic receptors were evaluated at 7 and 28 days post-MCAO or sham-operation. Compared with untreated rats, hAFSC-EV treatment significantly reduced cerebral infarct volume and BBB leakage, and enhanced microvessel and vascular density, along with angiogenesis. Neural markers such as BDNF, nestin, and doublecortin were significantly upregulated at 7 and/or 28 days post-MCAO. hAFSC-EV treatment ameliorated MCAO-induced bladder dysfunction by reducing peak voided volume, intercontraction interval, and bladder capacity, along with improving residual urine volume. hAFSC-EV treatment significantly increased bladder expression of BDNF and M3-muscarinic receptors, and recovers the expressions of M2, β3-adrenoceptor, and adenylate cyclase to near control levels at 7 and 28 days post-MCAO. hAFSC-EV treatment improves neurogenic bladder dysfunction and cerebral ischemia post-MCAO, potentially through reducing infarct volume and BBB disruption, enhancing neurogenesis and angiogenesis in the ischemic brain, and modulating the expression of bladder BDNF, β3-adrenoceptor, adenylate cyclase and muscarinic receptors. Show less

This study investigated the neuroprotective effects and mechanisms of cycloastragenol (CAG) on oxidative stress and neurological function in cerebral ischemia-reperfusion injury (CIRI) and oxygen-glucose deprivation/reoxygenation (OGD/R) models. In vivo, rats were given oral CAG daily for 28 days before CIRI induction. Cerebral infarction and hippocampal injury were assessed using TTC, Nissl, and HE staining. Neurological scores, morris water maze, grip strength tests, and brain water content were used to evaluate functional outcomes. Oxidative stress was determined by biochemical assays, DHE staining, and transmission electron microscopy, while Western blotting was performed to measure neuroprotective proteins. In vitro, primary neurons were treated with CAG and subjected to OGD/R. Cell viability was tested by CCK-8 assay, apoptosis and mitochondrial membrane potential were analyzed by flow cytometry, ROS levels were quantified, and MDA, SOD, and GSH were measured biochemically. Western blot further evaluated BDNF and NeuN expression to confirm in vivo findings. In vivo, CAG reduced infarct volume and edema, improved neurological deficits, preserved the structural integrity of neurons in the hippocampal CA1 region. CAG also promoted motor function recovery, markedly reduced MDA levels, increased SOD and GSH activity, and upregulated BDNF and NeuN expression. In vitro, CAG enhanced cell viability in the OGD/R model, reduced apoptosis, restored mitochondrial membrane potential, and significantly suppressed oxidative stress induced by ischemia-reperfusion. CAG effectively alleviated injury caused by cerebral and cellular ischemia-reperfusion by maintaining redox homeostasis, inhibiting oxidative stress, and promoting the expression of neuroprotective proteins, demonstrating promising neuroprotective potential. Show less