Search Results (42)

Background: Danhong injection (DHI), a standardized traditional Chinese medicine formulation, has shown clinical benefits in treating cerebrovascular diseases. Blood–brain barrier (BBB) disruption is a key pathological feature of ischemic stroke, but its modulation by DHI under hyperlipidemic conditions remains unclear. This study aimed to investigate the protective effects and mechanisms of DHI in cerebral ischemia/reperfusion injury (CI/RI) under hyperlipidemia, focusing on BBB integrity and the Wnt/β-catenin signaling pathway. Methods: Rats were divided into control, ischemic, hyperlipidemic, and treatment subgroups to evaluate DHI’s dose-dependent effects and pathway specificity using DKK1 inhibition. Assessments included neurological scores, TTC and Nissl staining, TEM, and molecular analyses (qRT-PCR/Western blot/immunofluorescence/immunohistochemistry). Results: DHI significantly improved neurological function, reduced cerebral infarct size, and alleviated cortical damage. DHI treatment upregulated the expression of tight junction proteins (Claudin-5, Occludin, ZO-1) and downregulated MMP-9 expression. Mechanistically, DHI promoted the nuclear translocation of β-catenin and increased the expression of Wnt3α, p-GSK-3β, and Cyclin D1, thereby activating the Wnt/β-catenin pathway. Additionally, DHI treatment increased the count of NeuN-positive neurons, suppressed astrocyte activation, and markedly reduced IgG infiltration in the ischemic cerebral cortex. These effects were reversed by DKK1. Conclusions: The results indicate that DHI protects BBB integrity and alleviates CI/RI in hyperlipidemic rats independently of direct lipid-lowering activity. Specifically, DHI activates the Wnt/β-catenin pathway by enhancing β-catenin nuclear translocation, which in turn mediates the upregulation of tight junction proteins and suppression of MMP-9, ultimately preserving BBB integrity. These findings support its therapeutic potential in ischemic stroke with comorbid hyperlipidemia. Full article

Hypertension contributes to brain dysfunction through apoptosis, oxidative stress, reduced neuronal connectivity, and neurotransmitter imbalance. Exercise training is a non-pharmacological strategy known to modulate these molecular alterations. This study investigated the effects of high-intensity interval training (HIIT) on transcriptomic changes in the cerebral cortex of spontaneously hypertensive rats (SHR) fed a high-fat diet (HFD). Rats were assigned to either a HIIT intervention group (HIIT-HFD-SHR) or a sedentary control group (HFD-SHR). Cortical RNA was extracted, sequenced using the Illumina NovaSeq 6000 platform, and analyzed with DESeq2. Functional enrichment was conducted using Metascape. RNA-seq identified 1223 differentially expressed genes (DEGs) (adjusted p < 0.05), with 51 remaining significant under stringent criteria (adjusted p < 0.001, |log₂FC| > 0.5). Among these, eight key genes were closely associated with the regulation of apoptosis and autophagy, including seven downregulated (Egr1, Atf3, Tgm2, Lgals1, Nr4a1, Plekhf1, Nupr1) and one upregulated (Trim39). This transcriptomic analysis following HIIT also modulated circadian rhythm, long-term memory processes, and hypoxia response in the hypertensive brain. These findings indicate that HIIT decreases apoptosis and autophagy and improves circadian rhythm, long-term memory, and hypoxia in hypertensive rats’ brains. Full article

Background/Objectives: Cerebral ischemia and reperfusion injury, induced by bilateral common carotid artery occlusion and reperfusion (BCCAO/R), cause extensive neuronal damage and cognitive impairment. Bouvardia ternifolia (BtD), a plant known for its anti-inflammatory and neuroprotective effects, may offer therapeutic benefits against ischemic injury. This study aimed to evaluate the neuroprotective effects of BtD root extract on neuronal integrity, oxidative stress, and p53 protein expression following global cerebral ischemia in rats. Methods: Adult male Sprague Dawley rats were subjected to the BCCAO/R procedure for 60 min, followed by six days of reperfusion. Experimental groups included BCCAO/R+BtD, BCCAO/R+silymarin (reference control), BCCAO/R+vehicle, and sham controls. Neuronal morphology in the cortex, striatum, hippocampus, and cerebellum was assessed histologically. Oxidative stress markers, including reactive oxygen species (ROS), lipid peroxidation (LPO), reduced glutathione (GSH), and superoxide dismutase (SOD), were measured, along with the expression of p53 protein. Results: Treatment with BtD significantly decreased oxidative stress markers—LPO (82.2%), ROS (88.2%), GSH (66.5%), and SOD (54%)—and reduced p53 expression levels by 75%. Histological evaluation revealed that neurons in the BCCAO/R+BtD and BCCAO/R+silymarin groups maintained normal morphology, characterized by elongated cells and well-defined nuclei. In contrast, the BCCAO/R+vehicle group exhibited marked neuronal damage, including pyknosis, nuclear fragmentation, and interstitial edema, particularly in the hippocampal CA1 and cortical regions. BtD treatment significantly preserved neuronal structure and enhanced antioxidant defenses. Conclusions:Bouvardia ternifolia extract demonstrates neuroprotective potential in cerebral ischemia by maintaining neuronal architecture, reducing oxidative stress, and modulating p53 expression, supporting its therapeutic relevance in ischemia–reperfusion injury. Full article

Cerebral ischemia/reperfusion (I/R) injury remains a significant contributor to adult neurological morbidity, primarily due to exacerbated neuroinflammation and cell apoptosis. These processes amplify brain damage through the release of various pro-inflammatory cytokines and pro-apoptotic mediators. Although long non-coding RNAs (lncRNAs) are increasingly recognized for their involvement in regulating diverse biological pathways, their precise role in cerebral I/R injury has not been fully elucidated. In the current study, transcriptomic profiling was conducted using a rat model of focal cerebral I/R, leading to the identification of lncRNA-1810026B05Rik—also referred to as CHASERR—as a novel lncRNA responsive to ischemic conditions. The elevated expression of this lncRNA was observed in mouse brain tissues subjected to middle cerebral artery occlusion followed by reperfusion (MCAO/R), as well as in primary cortical neurons derived from rats exposed to oxygen-glucose deprivation and subsequent reoxygenation (OGD/R). The results suggested that lncRNA-1810026B05RiK mediates the activation of the nuclear factor-kappaB (NF-κB) signaling pathway by physically binding to NF-kappa-B inhibitor alpha (IκBα) and promoting its phosphorylation, thus leading to neuroinflammation and neuronal apoptosis during cerebral ischemia/reperfusion. In addition, lncRNA-1810026B05Rik knockdown acts as an NF-κB inhibitor in the OGD/R and MCAO/R pathological processes, suggesting that lncRNA-1810026B05Rik downregulation exerts a protective effect on cerebral I/R injury. In summary, the lncRNA-1810026B05Rik has been identified as a critical regulator of neuronal apoptosis and inflammation through the activation of the NF-κB signaling cascade. This discovery uncovers a previously unrecognized role of 1810026B05Rik in the molecular mechanisms underlying ischemic stroke, offering valuable insights into disease pathology. Moreover, its involvement highlights its potential as a novel therapeutic target, paving the way for innovative treatment strategies for stroke patients. Full article

Background/Objectives: A maternal high-fat diet (HFD) impairs brain structure in offspring. In turn, fish oil (FO) rich in n-3 polyunsaturated fatty acids (PUFAs) has neuroprotective effects. Therefore, we investigated whether maternal HFD exposure affected the neurological reflexes, neuron morphology, and n-3 PUFA levels in the cerebral cortex of the offspring and whether these effects were mitigated by maternal FO consumption. Methods: Female Sprague Dawley rats received a control diet (CD, 10% Kcal fat) or HFD (45% Kcal fat) five weeks before mating and throughout pregnancy and lactation. From mating, a subgroup of HFD was supplemented with 11.4% FO into the diet (HFD-FO). Neurological reflexes were evaluated from postnatal day (PND) 3 until PND20. Brains were removed at PND22 for neuron morphology analysis. Moreover, fatty acid composition and transcripts of genes encoding for factors associated with synapse transmission (SNAP-25), plasticity (BDNF), transport of DHA (MFSD2a), and inflammation (NF-κB and IL-1β) were quantified in prefrontal, motor, and auditory cortices. Results: FO diminished the effects of HFD on the number of thin and mushroom-shaped dendritic spines in the cerebral cortex in both sexes. It also reversed the HFD effects on the motor and auditory reflexes in female and male offspring, respectively. In males, FO up-regulated Bdnf transcript levels in the motor cortex compared with CD and HFD. In females, n-3 PUFAs were higher in HFD and HFD-FO than in CD in the auditory cortex. Conclusions: Our results highlight the protective role of maternal dietary n-3 PUFAs in counteracting the effects induced by HFD on the acquisition of neurological reflexes and neuronal morphology in the cerebral cortex of the offspring of both sexes. Full article

Background: The role of sulfur-containing drugs, disulfiram (DSF) and N-acetylcysteine (NAC), in alleviating neuroinflammation is poorly understood. The objective of this study was to examine the effect of DSF and NAC on memory and on the metabolism of L-cysteine and inflammation-related parameters in the cerebral cortex of rats in a model of neuroinflammation induced by the administration of lipopolysaccharide (LPS). Methods: All the treatments were administered intraperitoneally for 10 days (LPS at a dose of 0.5 mg/kg b.w., DSF at a dose of 100 mg/kg b.w, and NAC at a dose of 100 mg/kg b.w.). Behavior was evaluated by the novel object recognition (NOR) test and object location (OL) test, and the level of brain-derived neurotrophic factor (BDNF) was assayed to evaluate neuronal functioning. Cerebral cortex homogenates were tested for hydrogen sulfide (H₂S), sulfane sulfur, sulfates, non-protein sulfhydryl groups (NPSH), nitric oxide (NO), and reactive oxygen species (ROS) by biochemical analysis. Results: Neither DSF nor NAC alleviated LPS-induced memory disorders estimated by the NOR test and OL test. The studied compounds also did not affect significantly the levels of BDNF, ROS, NO, H₂S, and sulfane sulfur in the cerebral cortex. However, we observed an increase in sulfate concentration in brain tissues after LPS treatment, while DSF and NAC caused an additional increase in sulfate concentration. On the other hand, our study showed that the administration of DSF or NAC together with LPS significantly enhanced the cortical level of NPSH, of which glutathione is the main component. Conclusions: Our study did not confirm the suggested potential of DSF and NAC to correct memory disorders; however, it corroborated the notion that they reduced oxidative stress induced by LPS by increasing the NPSH level. Additionally, our study showed an increase in sulfate concentration in the brain tissues after LPS treatment, which means the upregulation of sulfite and sulfate production in inflammatory conditions. Full article

Background: The cerebral microvasculature forms a dense network of interconnected blood vessels where flow is modulated partly by astrocytes. Increased neuronal activity stimulates astrocytes to release vasoactive substances at the endfeet, altering the diameters of connected vessels. Methods: Our study simulated the coupling between blood flow variations and vessel diameter changes driven by astrocytic activity in the rat somatosensory cortex. We developed a framework with three key components: coupling between the vasculature and synthesized astrocytic morphologies, a fluid dynamics model to compute flow in each vascular segment, and a stochastic process replicating the effect of astrocytic endfeet on vessel radii. Results: The model was validated against experimental flow values from the literature across cortical depths. We found that local vasodilation from astrocyte activity increased blood flow, especially in capillaries, exhibiting a layer-specific response in deeper cortical layers. Additionally, the highest blood flow variability occurred in capillaries, emphasizing their role in cerebral perfusion regulation. We discovered that astrocytic activity impacted blood flow dynamics in a localized, clustered manner, with most vascular segments influenced by two to three neighboring endfeet. Conclusions: These insights enhance our understanding of neurovascular coupling and guide future research on blood flow-related diseases. Full article

Background: The regulation of divalent metal transporter-1 (DMT1) by insulin has been previously described in Langerhans cells and significant neuroprotection was found by insulin and insulin-like growth factor 1 treatment during experimental cerebral ischemia in acute ischemic stroke patients and in a rat 6-OHDA model of Parkinson’s disease, where DMT1 involvement is described. According to the regulation of DMT1, previously described as a target gene of NF-kB in the early phase of post-ischemic neurodegeneration, both in vitro and in vivo, and because insulin controls the NFkB signaling with protection from ischemic cell death in rat cardiomyocytes, we evaluated the role of insulin in relation to DMT1 expression and function during ischemic neurodegeneration. Methods: Insulin neuroprotection is evaluated in differentiated human neuroblastoma cells, SK-N-SH, and in primary mouse cortical neurons exposed to oxygen glucose deprivation (OGD) for 8 h or 3 h, respectively, with or without 300 nM insulin. The insulin neuroprotection during OGD was evaluated in both cellular models in terms of cell death, and in SK-N-SH for DMT1 protein expression and acute ferrous iron treatment, performed in acidic conditions, known to promote the maximum DMT1 uptake as a proton co-transporter; and the transactivation of 1B/DMT1 mouse promoter, already known to be responsive to NF-kB, was analyzed in primary mouse cortical neurons. Results: Insulin neuroprotection during OGD was concomitant to the down-regulation of both DMT1 protein expression and 1B/DMT1 mouse promoter transactivation. We also showed the insulin-dependent protection from cell death after acute ferrous iron treatment. In conclusion, although preliminary, this evaluation highlights the peculiar role of DMT1 as a possible pharmacological target, involved in neuroprotection by insulin during in vitro neuronal ischemia and acute ferrous iron uptake. Full article

Excitotoxicity is a common pathological process in neurological diseases caused by excess glutamate. The purpose of this study was to evaluate the effect of gypenoside XVII (GP-17), a gypenoside monomer, on the glutamatergic system. In vitro, in rat cortical nerve terminals (synaptosomes), GP-17 dose-dependently decreased glutamate release with an IC₅₀ value of 16 μM. The removal of extracellular Ca²⁺ or blockade of N-and P/Q-type Ca²⁺ channels and protein kinase A (PKA) abolished the inhibitory effect of GP-17 on glutamate release from cortical synaptosomes. GP-17 also significantly reduced the phosphorylation of PKA, SNAP-25, and synapsin I in cortical synaptosomes. In an in vivo rat model of glutamate excitotoxicity induced by kainic acid (KA), GP-17 pretreatment significantly prevented seizures and rescued neuronal cell injury and glutamate elevation in the cortex. GP-17 pretreatment decreased the expression levels of sodium-coupled neutral amino acid transporter 1, glutamate synthesis enzyme glutaminase and vesicular glutamate transporter 1 but increased the expression level of glutamate metabolism enzyme glutamate dehydrogenase in the cortex of KA-treated rats. In addition, the KA-induced alterations in the N-methyl-D-aspartate receptor subunits GluN2A and GluN2B in the cortex were prevented by GP-17 pretreatment. GP-17 also prevented the KA-induced decrease in cerebral blood flow and arginase II expression. These results suggest that (i) GP-17, through the suppression of N- and P/Q-type Ca²⁺ channels and consequent PKA-mediated SNAP-25 and synapsin I phosphorylation, reduces glutamate exocytosis from cortical synaptosomes; and (ii) GP-17 has a neuroprotective effect on KA-induced glutamate excitotoxicity in rats through regulating synaptic glutamate release and cerebral blood flow. Full article

Luteolin-7-O-β-d-glucuronide (LGU) is a major active flavonoid glycoside compound that is extracted from Ixeris sonchifolia (Bge.) Hance, and it is a Chinese medicinal herb mainly used for the treatment of coronary heart disease, angina pectoris, cerebral infarction, etc. In the present study, the neuroprotective effect of LGU was investigated in an oxygen glucose deprivation (OGD) model and a middle cerebral artery occlusion (MCAO) rat model. In vitro, LGU was found to effectively improve the OGD-induced decrease in neuronal viability and increase in neuronal death by a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and a lactate dehydrogenase (LDH) leakage rate assay, respectively. LGU was also found to inhibit OGD-induced intracellular Ca²⁺ overload, adenosine triphosphate (ATP) depletion, and mitochondrial membrane potential (MMP) decrease. By Western blotting analysis, LGU significantly inhibited the OGD-induced increase in expressions of receptor-interacting serine/threonine-protein kinase 3 (RIP3) and mixed lineage kinase domain-like protein (MLKL). Moreover, molecular docking analysis showed that LGU might bind to RIP3 more stably and firmly than the RIP3 inhibitor GSK872. Immunofluorescence combined with confocal laser analyses disclosed that LGU inhibited the aggregation of MLKL to the nucleus. Our results suggest that LGU ameliorates OGD-induced rat primary cortical neuronal injury via the regulation of the RIP3/MLKL signaling pathway in vitro. In vivo, LGU was proven, for the first time, to protect the cerebral ischemia in a rat middle cerebral artery occlusion (MCAO) model, as shown by improved neurological deficit scores, infarction volume rate, and brain water content rate. The present study provides new insights into the therapeutic potential of LGU in cerebral ischemia. Full article

A disruption of the blood–brain barrier (BBB) is a crucial pathophysiological change that can impact the outcome of a stroke. Ribosomal protein S6 (S6) and protein kinase B (Akt) play significant roles in early cerebral ischemia-reperfusion injury. Studies have suggested that branched-chain amino acids (BCAAs) may have neuroprotective properties for spinal cord or brain injuries. Therefore, we conducted research to investigate if leucine, one of the BCAAs, could offer neuroprotection and alter BBB disruption, along with its effects on the phosphorylation of S6 and Akt during the early phase of cerebral ischemia-reperfusion, specifically within the thrombolytic therapy time window. In rats, ten min after left middle cerebral artery occlusion (MCAO), 5 µL of 20 mM L-leucine or normal saline was injected into the left lateral ventricle. After two hours of reperfusion following one hour of MCAO, we determined the transfer coefficient (K_i) of ¹⁴C-α-aminoisobutyric acid to assess the BBB disruption, infarct size, and phosphorylation of S6 and Akt. Ischemia-reperfusion increased the K_i (+143%, p < 0.001) and the intra-cerebroventricular injection of leucine lowered the K_i in the ischemic-reperfused cortex (−34%, p < 0.001). Leucine reduced the percentage of cortical infarct (−42%, p < 0.0001) out of the total cortical area. Ischemia-reperfusion alone significantly increased the phosphorylation of both S6 and Akt (p < 0.05). However, the administration of leucine had no further effect on the phosphorylation of S6 or Akt in the ischemic-reperfused cortex. This study suggests that an acute increase in leucine levels in the brain during early ischemia-reperfusion within a few hours of stroke may offer neuroprotection, possibly due to reduced BBB disruption being one of the major contributing factors. Leucine did not further increase the already elevated phosphorylation of S6 or Akt by ischemia-reperfusion under the current experimental conditions. Our data warrant further studies on the effects of leucine on neuronal survival and its mechanisms in the later stages of cerebral ischemia-reperfusion. Full article

Modeling chronic cortical demyelination allows the study of long-lasting pathological changes observed in multiple sclerosis such as failure of remyelination, chronically disturbed functions of oligodendrocytes, neurons and astrocytes, brain atrophy and cognitive impairments. We aimed at generating an animal model for studying the consequences of chronic cortical demyelination and meningeal inflammation. To induce long-lasting cortical demyelination and chronic meningeal inflammation, we immunized female Lewis rats against myelin oligodendrocyte glycoprotein (MOG) and injected lentiviruses for continuing overexpression of the cytokines TNFα and IFNγ in the cortical brain parenchyma. Immunization with MOG and overexpression of TNFα and IFNγ led to widespread subpial demyelination and meningeal inflammation that were stable for at least 10 weeks. We demonstrate here that immunization with MOG is necessary for acute as well as chronic cortical demyelination. In addition, long-lasting overexpression of TNFα and IFNγ in the brain parenchyma is sufficient to induce chronic meningeal inflammation. Our model simulates key features of chronic cortical demyelination and inflammation, reminiscent of human multiple sclerosis pathology. This will allow molecular, cellular and functional investigations for a better understanding of the adaptation mechanisms of the cerebral cortex in multiple sclerosis. Full article

In the cerebral cortex, glutamate activates NMDA receptors (NMDARs), localized in noradrenergic neurons, inducing noradrenaline release that may have a permissive effect on glutamatergic transmission, and therefore, on the modulation of long-term plasticity. ATP is co-released with noradrenaline, and with its metabolites (ADP and adenosine) is involved in the purinergic modulation of electrically-evoked noradrenaline release. However, it is not known if noradrenaline release evoked by activation of NMDARs is also under purinergic modulation. The present study aimed to investigate and to characterize the purinergic modulation of noradrenaline release evoked by NMDARs. Stimulation of rat cortical slices with 30 µM NMDA increased noradrenaline release, which was inhibited by ATP upon metabolization into ADP and adenosine and by the selective agonists of A₁ and A_2A receptors, CPA and CGS2680, respectively. It was also inhibited by UTP and UDP, which are mainly released under pathophysiological situations. Characterization of the effects mediated by these compounds indicated the involvement of P2Y₁, P2Y₆, A₁ and A_2A receptors. It is concluded that, in the rat brain cortex, NMDA-evoked noradrenaline release is modulated by several purinergic receptors that may represent a relevant mechanism to regulate the permissive effect of noradrenaline on NMDA-induced neuroplasticity. Full article

Autophagic dysfunction is one of the main mechanisms of cadmium (Cd)-induced neurotoxicity. Puerarin (Pue) is a natural antioxidant extracted from the medicinal and edible homologous plant Pueraria lobata. Studies have shown that Pue has neuroprotective effects in a variety of brain injuries, including Cd-induced neuronal injury. However, the role of Pue in the regulation of autophagy to alleviate Cd-induced injury in rat cerebral cortical neurons remains unclear. This study aimed to elucidate the protective mechanism of Pue in alleviating Cd-induced injury in rat cerebral cortical neurons by targeting autophagy. Our results showed that Pue alleviated Cd-induced injury in rat cerebral cortical neurons in vitro and in vivo. Pue activates autophagy and alleviates Cd-induced autophagic blockade in rat cerebral cortical neurons. Further studies have shown that Pue alleviates the Cd-induced inhibition of autophagosome–lysosome fusion, as well as the inhibition of lysosomal degradation. The specific mechanism is related to Pue alleviating the inhibition of Cd on the expression levels of the key proteins Rab7, VPS41, and SNAP29, which regulate autophagosome–lysosome fusion, as well as the lysosome-related proteins LAMP2, CTSB, and CTSD. In summary, these results indicate that Pue alleviates Cd-induced autophagic dysfunction in rat cerebral cortical neurons by alleviating autophagosome–lysosome fusion dysfunction and lysosomal degradation dysfunction, thereby alleviating Cd-induced neuronal injury. Full article

Ischemic stroke is one of the principal causes of morbidity and mortality around the world. The pathophysiological mechanisms that lead to the formation of the stroke lesions range from the bioenergetic failure of the cells and the intense production of reactive oxygen species to neuroinflammation. The fruit of the açaí palm, Euterpe oleracea Mart. (EO), is consumed by traditional populations in the Brazilian Amazon region, and it is known to have antioxidant and anti-inflammatory properties. We evaluated whether the clarified extract of EO was capable of reducing the area of lesion and promoting neuronal survival following ischemic stroke in rats. Animals submitted to ischemic stroke and treated with EO extract presented a significant improvement in their neurological deficit from the ninth day onward. We also observed a reduction in the extent of the cerebral injury and the preservation of the neurons of the cortical layers. Taken together, our findings indicate that treatment with EO extract in the acute phase following a stroke can trigger signaling pathways that culminate in neuronal survival and promote the partial recovery of neurological scores. However, further detailed studies of the intracellular signaling pathways are needed to better understand the mechanisms involved. Full article