Neurochemical Research最新文献

Memory impairment is one of the cognitive symptoms in Huntington’s disease (HD) which appears before motor dysfunction in patients. Various molecular mechanisms, including disruptions in neurotrophins levels, are involved in the occurrence of memory problems in HD. Alpha-pinene (APN), a member of the monoterpene family, exhibited beneficial effects in animal models of neurodegenerative disorders. As a result, this study assessed the impact of APN on memory in the 3-nitropropionic acid (3-NP) induced model of HD in rats. Male Wistar rats received saline, 3-NP to model HD, or APN (1, 5, or 10 mg/kg) plus 3-NP for 21 days to assess APN’s effects. Working and spatial memory were examined by the Y-maze and Morris-water-maze (MWM) tests. The mRNA levels of neurotrophins and their receptors in the brain cortex and hippocampus of the rats were quantitatively assessed through Reverse Transcription Quantitative Polymerase Chain Reaction (RT-qPCR) analysis. The results showed that APN, at all three doses, significantly prevented the disease phenotype induced by 3-NP administration. In addition, APN treatment elevated the gene expression levels of BDNF, TrkA, TrkB, and CREB, while significantly decreasing P75 NTR showing a dose-dependent effect in the brain cortex and hippocampus, compared to the 3-NP group. These findings suggest that APN alleviates 3-NP-induced memory deficits by enhancing neurotrophins and their receptor levels in an animal model of HD.

Bupivacaine (BUP) is a commonly used local anesthetic, while SH-SY5Y cells are a human neuroblastoma cell line frequently employed in research on neurotoxicity and neuroprotective mechanisms. To assess the neurotoxic effects of BUP on SH-SY5Y cells and the role of threonine-serine protein kinase B (Akt) signaling in BUP-induced nerve injury. SH-SY5Y cells were divided into three groups: the control group (Control), BUP group, and BUP + SC79 group. Cell viability was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the level of reactive oxygen species (ROS) in cells was detected using the dihydroethidium fluorescence probe method, and changes in mitochondrial membrane potential were detected by flow cytometry, while BUP-induced apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The effects of BUP on Bax, Bcl-2, Caspase-3, Caspase-9, Akt and phosphorylated Akt (p-Akt) were analyzed by Western blot (WB). Compared with the control group, the BUP group and the BUP + SC79 group showed significantly reduced cell viability, significantly increased apoptosis, significantly elevated ROS levels, significantly decreased JC-1 polymer/monomer ratio, significantly increased protein levels of Bax, caspase-3, caspase-9, Akt, and p-Akt, and significantly decreased Bcl-2 protein levels (P < 0.05). However, compared with the BUP group, the BUP + SC79 group exhibited significantly increased cell viability (P = 0.022), significantly reduced apoptosis rate (P = 0.017), significantly decreased ROS levels (P = 0.015), significantly increased JC-1 polymer/monomer ratio (P = 0.024), significantly reduced protein levels of Bax, caspase-3, caspase-9, Akt, and p-Akt (P = 0.033, 0.028, 0.030, 0.035, and 0.005, respectively), and significantly increased Bcl-2 protein levels (P = 0.024). BUP can reduce the viability of SH-SY5Y cells and promote apoptosis, which may be related to its inhibitory effect on Akt protein activity.

Bay k-8644, an activator of L-type voltage-gated calcium channels, induces self-injurious behaviors in mice. Although previous studies using animal models have suggested the possible implications of neuroinflammation in self-injurious behaviors, this has not yet been elucidated in the context of Bay k-8644-induced self-injurious behaviors. In this study, Bay k-8644 (50 µg, i.c.v.)-induced self-injurious behaviors were accompanied by increased expression of endothelin (ET)-1, platelet-activating factor (PAF) receptors, and Iba-1 in the striatum. Pretreatment with the ET receptor antagonist bosentan (10 mg/kg, i.p.), the PAF receptor antagonist ginkgolide B (10 mg/kg, i.p.), or the microglial activation inhibitor minocycline (40 mg/kg/day for 5 days, i.p.) significantly inhibited Bay k-8644-induced self-injurious behaviors and microglial activation in the striatum. Interestingly, bosentan also suppressed Bay k-8644-induced PAF receptor expression, indicating that ET-1 may act as an upstream modulator of the PAF signaling under these experimental conditions. Bay k-8644-induced ET-1 expression and consequent pro-inflammatory changes were reversed by the protein kinase C (PKC) inhibitor NPC-15,437 and the Ca²⁺/calmodulin-dependent kinase II (CaMKII) inhibitor KN-93. Moreover, Bay k-8644-induced self-injurious behaviors and microglial activation were significantly potentiated by exogenous ET-1 administration (10 pmol, i.c.v.) or by weak neuroinflammation in the striatum induced by systemic injection of low-dose lipopolysaccharide (LPS; 1 mg/kg, i.p.). Our results suggest that neuroinflammatory changes associated with ET-1/PAF signaling in the striatum contribute to Bay k-8644-induced self-injurious behaviors.

Parkinson’s Disease (PD) is a neurodegenerative disorder characterized by the pathological accumulation of alpha-synuclein (α-syn) in the neuronal cell bodies of the substantia nigra. The glymphatic system within the Central Nervous System (CNS) is responsible for clearing metabolic waste and abnormal proteins and its dysfunction may significantly contribute to the pathogenesis of PD. Our previous study showed that OAB-14, the novel small molecular compound, showed a great potential effect in APP/PS1 transgenic mice. Given the similarities in the pathogenesis of PD and Alzheimer’s disease (AD), it is pertinent to explore the therapeutic potential of OAB-14 in the context of PD. This study utilized a rotenone-induced PD mice model to evaluate the effects of oral administration of OAB-14, and its underlying mechanisms. Here we confirmed the neuroprotective effect and motor improvement of OAB-14 in rotenone-induced PD model mice. Our research has shown that OAB-14 is capable of enhancing the glymphatic system function by promoting the influx and efflux of the CSF tracers to the brain and deep cervical lymph nodes, respectively, to promote the clearance of α-syn. In addition, OAB-14 could down-regulate MyD88, NF-kB (Ser 536) phosphorylation, and TLR4 to reduce glial cell activation; and down-regulate cleaved-caspase1, NLRP3, ASC, IL-1β, IL-6, IL-18, TNF-α, and IL-10 to reduce the expression of inflammatory vesicles and pro-inflammatory factors, and to reduce neuronal oxidative stress. In summary, OAB-14 may promote the clearance of brain α-syn through the glial lymphatic system, inhibit the α-syn/TLR4/NF-κB/NLRP3 inflammatory pathway, and improve movement disorders.

Ferroptosis is an iron-dependent regulatory cell death characterized by lipid peroxidation. The molecular mechanism of calcium/calmodulin-dependent protein kinase II β (CAMK2B) affecting cerebral ischemic injury through autophagy-dependent ferroptosis is still unclear. Here, we aimed to study the regulatory effect of CAMK2B on autophagy-dependent ferroptosis and its effect on cerebral ischemic injury. We found that CAMK2B was significantly upregulated in oxygen and glucose deprivation/recovery (OGD/R)-induced PC12 cells and primary hippocampal neurons. CAMK2B knockdown inhibited OGD/R-induced autophagy-dependent ferroptosis in PC12 cells and primary hippocampal neurons. In addition, CAMK2B was co-localized with amphiregulin (AREG) in PC12 cells, and overexpression of AREG reversed the effect of CAMK2B knockdown on OGD/R-induced autophagy-dependent ferroptosis in PC12 cells and primary hippocampal neurons. Further molecular mechanism studies showed that AREG enhanced the transcriptional activation of embryonic lethal abnormal vision-like 1 (ELAVL1) through Jun Proto-Oncogene (c-Jun), thereby inducing autophagy-dependent ferroptosis in PC12 cells and primary hippocampal neurons. Moreover, CAMK2B was significantly upregulated in the ipsilateral penumbra neurons of cerebral ischemia-reperfusion (I/R) mice, and the level of autophagy-dependent ferroptosis was increased in the brain tissue of I/R mice. Knockdown of CAMK2B alleviated neuronal damage by inhibiting autophagy-dependent ferroptosis in the brain tissue of model mice. This study suggests that CAMK2B plays a key role in regulating neuronal autophagy-dependent ferroptosis, and CAMK2B may be a potential target for the treatment of cerebral I/R injury.

Electroacupuncture (EA) might exert endogenous protective effects on astrocytes in ischemic stroke. Nevertheless, the biological regulatory processes involved have not been identified. The astrocytes were randomly divided into six groups: the control, oxygen-glucose deprivation/reoxygenation (OGD/R), EA serum, METTL3, lncRNA MALAT1 (MALAT1) and AQP4 groups. OGD/R was performed to establish in vitro models of ischemic stroke. EA serum was obtained from rats that were received EA treatment 3 times at “Renzhong” (GV26) and “Baihui” (GV20) acupoints. The morphological characteristics of astrocytes were identified by microscopy and immunohistochemistry. Mitochondrial ultrastructure was observed using transmission electron microscopy. Cell viability and apoptosis rate were measured with cell counting kit-8 and flow cytometry, respectively. RNA m6A levels were detected by colorimetry, and the expression levels of METTL3, MALAT1 and AQP4 were tested with Western blot and quantitative real-time PCR. 10% EA serum was found to be more effective in improving astrocyte morphology and cell viability. EA serum improved mitochondrial ultrastructure, the viability and apoptosis of astrocytes in OGD/R condition, whereas overexpression of METTL3, MALAT1 and AQP4 inhibited the protective effect of EA serum on astrocytes. Furthermore, EA serum down-regulated the level of RNA m6A and the expression levels of METTL3, MALAT1 and AQP4 in OGD/R condition, while overexpression of METTL3, MALAT1 and AQP4 reversed the down-regulatory effects of EA serum. EA serum attenuates OGD/R-induced astrocyte damage in vitro, and this protective role might be achieved by down-regulating the AQP4 via m6A methylation of MALAT1.

Neurological dysfunction following stroke presents a significant challenge for patients. Recent studies suggest that angiogenesis can improve neurological function and enhance neuronal survival after ischemic stroke. Dexmedetomidine exhibits neuroprotective effects through various mechanisms; therefore, this study aimed to investigate whether it promotes angiogenesis and improves neurological function after stroke. A mouse model of ischemic stroke was developed by embolizing the middle cerebral arteries. Neurological function was assessed using scoring methods, the water maze test, and histological analyses, including Nissl and hematoxylin and eosin staining, to evaluate neuronal survival in the ischemic penumbra. Angiogenesis was observed through immunofluorescence staining, whereas pathway protein expression was analyzed via western blotting. Additionally, a model of oxygen-glucose deprivation/reoxygenation was established in mouse cerebral microvascular cells to conduct angiogenesis-related experiments. Dexmedetomidine reduced cerebral infarction size, alleviated neurological damage, promoted angiogenesis in the ischemic penumbra, and decreased neuronal death through the Nrf2/HO-1/VEGF pathway. However, these neuroprotective effects were reversed by the NRF2 inhibitor ML385. In vitro, dexmedetomidine enhanced the proliferation, migration, and tube-formation of cerebral microvascular cells in mice. ML385 also reversed the protective effects of dexmedetomidine against hypoxia and glucose deprivation-induced axonal damage. Dexmedetomidine enhances angiogenesis, reduces neuronal damage, and promotes cerebral microvascular cell migration and tube formation in the ischemic penumbra of an ischemic stroke mouse model through the Nrf2/HO-1/VEGF pathway.

Graphical Abstract

Ischemic stroke remains a primary cause of mortality and morbidity, with ferroptosis emerging as a critical mechanism underlying neuronal damage post-ischemic injury. This study aims to elucidate the mechanisms of ferroptosis in ischemic stroke and assess the therapeutic potential of electroacupuncture, with emphasis on the NCOA4-FTH1 signaling pathway. After establishing a mouse model of middle cerebral artery occlusion (MCAO), we employed a combination of behavioral assessments and molecular techniques, including transmission electron microscopy, immunofluorescence, and Western blotting, to investigate the impact of electroacupuncture on ferroptosis markers. In addition, we constructed in vivo models of NCOA4 gene silencing and overexpression using adeno-associated virus (AAV) to verify whether electroacupuncture modulates the mechanism of ischemic stroke ferroptosis via the NCOA4-FTH1 signaling pathway. Our findings indicated that electroacupuncture could significantly downregulate NCOA4 expression while upregulating FTH1 and GPX4 levels in affected brain regions of MCAO mice. This resulted in reduced MDA levels, decreased iron ion concentration, a smaller brain infarct area, and improved motor function (p < 0.05). After constructing in vivo models of AAV-mediated NCOA4 gene silencing and overexpression, we demonstrated that electroacupuncture could attenuate iron deposition and inhibit ferroptosis in neurons by suppressing NCOA4 and upregulating FTH1, thereby ameliorating neurological deficits in the ischemic stroke model. These results suggest that electroacupuncture modulates ferroptosis through the NCOA4-FTH1 pathway, offering a novel therapeutic approach for neuroprotection following ischemic stroke.

Despite decades of research in brain energy metabolism and to what extent different cell types utilize distinct substrates for their energy metabolism, this topic remains a vibrant area of neuroscience research. In this review, we focus on the substrates utilized by the inhibitory GABAergic neurons, which has been less explored than glutamatergic neurons. First, we discuss how GABAergic neurons may utilize both glucose, lactate, or ketone bodies under different functional conditions, and provide some preliminary data suggesting that unlike glutamatergic neurons, GABAergic neurons work well when substrate supply is restricted to lactate. We end by discussing the role of GABAergic neuron energy metabolism in pathologies where failure of inhibitory function play a central role, namely epilepsy, hepatic encephalopathy, and Alzheimer’s disease.

The accumulation of amyloid β (Aβ) protein, derived from the amyloid precursor protein (APP), plays a pivotal role in the pathogenesis of Alzheimer’s disease (AD) by inducing neuronal cell injury. This study investigated the specific functions of ubiquitin-specific protease 1-associated factor 1 (UAF1) in mediating the neurotoxic effects triggered on Aβ. To model AD-related neuronal injury in vitro and in vitro, SH-SY5Y cells exposed to Aβ_25-35 and APPswe/PS1dE9 (APP/PS1) transgenic mice were utilized. Compared with control mice, UAF1 levels were significantly elevated in the hippocampus of experimental mice. In vitro experiments showed that UAF1 knockdown reduced Aβ-induced apoptosis and enhanced cell viability. Furthermore, UAF1 knockdown markedly suppressed Aβ_25-35 -induced pyroptosis in SH-SY5Y cells and reduced the production of IL-1β and IL-18 through the nucleotide-binding domain and leucine-rich repeat containing family pyrin domain-containing 3 (NLRP3)/Gasdermin D pathway. Mechanistic analyses revealed that UAF1 directly binds to NLRP3 to mediate its effects. In vivo, UAF1 knockdown mitigated cognitive deficits, decreased APP expression, Aβ plaque deposition, and reduced hyperphosphorylated Tau levels. These findings underscore the critical role of UAF1 in regulating neuronal apoptosis and pyroptosis, thereby highlighting its potential as a promising therapeutic target for AD.