[Therapeutic effect and mechanism of Xiaoyao Kangai Jieyu Recipe on mice with breast cancer related depression through regulating COX pathway].

This study aimed to investigate the intervention effect and mechanism of Xiaoyao Kangai Jieyu Recipe(XKJR) on hip-pocampal microglia and neuronal damage in mice with breast cancer related depression. The mouse model of breast cancer related depression was established by inoculation of 4T1 breast cancer cells in axilla and subcutaneous injection of corticosterone(30 mg·kg~(-1)). The successfully modeled mice were randomly divided into a model group, a positive drug group(capecitabine 60 mg·kg~(-1)+fluoxetine 19.5 mg·kg~(-1)), and XKJR group(19.5 mg·kg~(-1) crude drug), with 6 in each group. Another 6 normal mice were taken as a normal group. The administration groups were given corresponding drugs by gavage, while the normal and model groups were given an equal volume of distilled water, once a day for 21 consecutive days. The depressive behavior of mice was assessed by glucose consumption test, open field test and novelty-suppressed feeding test. Hematoxylin and eosin(HE) staining and tumor suppression rate were used to evaluate the changes of axillary tumors. The mRNA expressions and the relative protein expressions of interleukin-1ß(IL-1ß), interleukin-18(IL-18), cyclooxyganese-2(COX-2) and glutamyl-prolyl-tRNA synthetase(EPRs) in the hippocampus of mice were determined by quantitative real-time polymerase chain reaction(qRT-PCR) and immunohistochemistry, respectively. Immunofluorescence was performed to detect the mean fluorescence intensity of CD11b, a marker of hippocampal microglia activation. Nissler staining and transmission electron microscopy were employed to observe the morphological changes and the ultramorphological changes of hippocampal neurons, respectively. The experimental results indicated that compared with the normal group, the model group had reduced glucose consumption and lowered number of total activities in open field test(P<0.05, P<0.01), prolonged first feeding latency in no-velty-suppressed feeding test(P<0.01), and significant depression-like behavior; the contents of IL-1ß, IL-18, COX-2, and EPRs in hippocampus were increased(P<0.05, P<0.01), with hippocampal microglia activation and obvious neuronal damage. Compared with the model group, the positive drug group and the XKJR group presented an improvement in depressive behaviors, a decrease in the contents of IL-1ß, IL-18, COX-2 and EPRs in hippocampus, and an alleviation in the activation of hippocampal microglia and neuronal damage; the tumor suppression rates of positive drug and XKJR were 40.32% and 48.83%, respectively, suggesting a lower tumor growth rate than that of the model group. In summary, XKJR may improve hippocampal microglia activation and neuronal damage in mice with breast cancer related depression through activating COX signaling pathway.

Neuronal Differentiation and Outgrowth Effect of Thymol in Trachyspermum ammi Seed Extract via BDNF/TrkB Signaling Pathway in Prenatal Maternal Supplementation and Primary Hippocampal Culture.

Reviving the neuronal functions in neurodegenerative disorders requires the promotion of neurite outgrowth. Thymol, which is a principal component of Trachyspermum ammi seed extract (TASE), is reported to have neuroprotective effects. However, the effects of thymol and TASE on neuronal differentiation and outgrowth are yet to be studied. This study is the first report investigating the neuronal growth and maturation effects of TASE and thymol. Pregnant mice were orally supplemented with TASE (250 and 500 mg/kg), thymol (50 and 100 mg/kg), vehicle, and positive controls. The supplementation significantly upregulated the expression of brain-derived neurotrophic factor (BDNF) and early neuritogenesis markers in the pups' brains at post-natal day 1 (P1). Similarly, the BDNF level was significantly upregulated in the P12 pups' brains. Furthermore, TASE (75 and 100 µg/mL) and thymol (10 and 20 µM) enhanced the neuronal polarity, early neurite arborization, and maturation of hippocampal neurons in a dose-dependent manner in primary hippocampal cultures. The stimulatory activities of TASE and thymol on neurite extension involved TrkB signaling, as evidenced by attenuation via ANA-12 (5 µM), which is a specific TrkB inhibitor. Moreover, TASE and thymol rescued the nocodazole-induced blunted neurite extension in primary hippocampal cultures, suggesting their role as a potent microtubule stabilizing agent. These findings demonstrate the potent capacities of TASE and thymol in promoting neuronal development and reconstruction of neuronal circuitry, which are often compromised in neurodegenerative diseases and acute brain injuries.

A Review of Aspects of Synaptic Plasticity in Hippocampus via mT Extremely Low-Frequency Magnetic Fields.

The subthreshold magnetic modulation technique stimulates cells with mT extremely low-frequency magnetic fields (ELF-MFs), which are insufficient to induce neuronal action potentials. Although they cannot directly induce resting neurons to discharge, mT magnetic stimulation can regulate the excitability of the nervous system, which regulates learning and memory by some unknown mechanisms. Herein, we describe the regulation of mT ELF-MFs with different parameters on synaptic plasticity in hippocampal neurons. Additionally, we summarize the latest research on the possible mechanism of the effect of ELF-MFs on synaptic plasticity. Some studies have shown that ELF-MFs are able to inhibit long-term potentiation (LTP) by increasing concentration of intracellular Ca2+ concentration ([Ca2+ ]i ), as well as concentration of reactive oxygen species. The research in this paper has significance for the comprehensive understanding of relevant neurological mechanisms of learning and memory by mT ELF-MFs stimulation. However, more high-quality research is necessary to determine the regulatory mechanism of mT ELF-MFs on synaptic plasticity in order to optimize this technique as a treatment for neurological diseases. © 2023 Bioelectromagnetics Society.

[Galangin alleviates learning and memory impairments in APP/PS1 double- transgenic mice by regulating Akt/MEF2D/Beclin-1 signaling pathway].

The study aimed to investigate the effects of galangin on learning and memory impairments and Akt/MEF2 D/Beclin-1 signaling pathway in APP/PS1 double-transgenic mice. The mice in this experiment were divided into the normal group, model group, low-(25 mg·kg~(-1)), medium-(50 mg·kg~(-1)), and high-dose(100 mg·kg~(-1)) galangin groups, donepezil(3 mg·kg~(-1)) group, Akt inhibitor(25 mg·kg~(-1)) group, and autophagy inhibitor(30 mg·kg~(-1)) group, with ten in each group, and administered with the corresponding drugs for 30 successive days. On the 24 th day of medication, the water maze and dark avoidance tests were performed. The levels of p-tau, ß-amyloid peptide 1-42(Aß_(42)), acetylcholinesterase(AChE), ß-site amyloid precursor protein cleaving enzyme 1(BACE1), and amyloid precursor protein(APP) in hippocampus were detected by ELISA, the Beclin-1 mRNA expression by RT-PCR, the expression of Aß_(42) and glial fibrillary acidic protein(GFAP) by immunohistochemistry, and the expression of myocyte enhancer factor 2 D(MEF2 D) by immunofluorescence assay. The pathological changes in hippocampus were observed after HE staining, and the expression of Akt, MEF2 D, and Beclin-1 in hippocampus were assayed by Western blot. These results showed that compared with the normal group, the model group exhibited prolonged swimming time, increased number of errors and electric shocks, up-regulated p-tau, Aß_(42), APP, AChE, BACE1, GFAP, and Beclin-1, shortened incubation period, decreased p-Akt and MEF2 D, and obvious hippocampal injury. Compared with the model group, donepezil and galangin shortened the swimming time, reduced the number of errors and electric shocks, down-regulated the expression of p-tau, Aß_(42), APP, AChE, BACE1, GFAP, and Beclin-1, prolonged the incubation period, up-regulated p-Akt and MEF2 D, and improved the pathological changes in hippocampus. Compared with the autophagy inhibitor group, galangin prolonged the swimming time, elevated the number of errors and electric shocks, enhanced the expression of p-tau, Aß_(42), APP, AChE, BACE1, GFAP, and Beclin-1, shortened the incubation period, and diminished the expression of p-Akt and MEF2 D. In conclusion, galangin improves the learning and memory impairments and hippocampal neuron injury of APP/PS1 mice, which may be related to its regulation of Akt/MEF2 D/Beclin-1 signaling pathway.

Sinisan Protects Primary Hippocampal Neurons Against Corticosterone by Inhibiting Autophagy via the PI3K/Akt/mTOR Pathway.

Objective: Corticosterone causes significant neurotoxicity in primary hippocampal neurons which is associated with depression. Dysfunctional autophagy is implicated in cognitive impairment and depressive-like behavior. The traditional Chinese medicine Sinisan (SNS) is highly effective in clinical treatment of depression. However, the molecular mechanisms underlying therapeutic effects of SNS are unknown. Purpose: The aim of this study was to elucidate the protective effect of SNS and the underlying mechanisms against corticosterone-induced neuronal damage. Study Design: The effects of serum derived from rats containing SNS (or untreated controls) on the expression of autophagy-related molecules in primary rat hippocampal neurons exposed to different concentrations of corticosterone for different intervals were explored. Methods: CCK-8 assay, LDH assay were used to analyze cell viability and LDH activity. Western blot, qRT-PCR, and immunofluorescence assays were used to determine protein and mRNA expression levels of molecules such as LC3, p62, Beclin1, ULK1, PI3K, p-PI3K, Akt p-Akt, mTOR, p-mTOR, p70S6, p-p70S6, 4ebp1 and p-4ebp1. Results: Corticosterone induced a dose- and time-dependent reduction in cellular viability. Moreover, corticosterone (100-400 µM) treatment for 24 h increased LC3-II/LC3-I protein ratio, increased Beclin1 and ULK1 protein expression levels, and decreased p62, PI3K, p-PI3K, p-Akt, p-mTOR, p-p70S6, and p-4ebp1 protein expression levels. Notably, SNS-containing serum reversed corticosterone-induced reduction of neuronal viability, and increased p62, PI3K, p-Akt, p-mTOR, p-p70S6, and p-4ebp1 protein and mRNA expression levels. In addition, SNS-containing serum decreased LC3-II/LC3-I protein ratio, and downregulated Beclin1, and ULK1 protein and mRNA expression in primary hippocampal neurons. Conclusion: SNS protects primary hippocampal neurons against corticosterone-induced neurotoxicity by preventing excessive autophagy through activation of PI3K/AKT/mTOR pathway.

Naofucong Ameliorates High Glucose Induced Hippocampal Neuron Injury Through Suppressing P2X7/NLRP1/Caspase-1 Pathway.

P2X7/NLRP1/caspase-1 mediated neuronal injury plays an important role in diabetic cognitive impairment and eventually inflammatory cascade reaction. Chinese herbal compound Naofucong has been mainly used to treat cognitive disorders in Traditional Chinese Medicine The present study aimed to investigate whether its neuroprotective effects might be related to the inhibition of P2X7R/NLRP1/caspase-1 mediated neuronal injury or not. In this study, high glucose-induced HT22 hippocampal neurons were used to determine Naofucong-containing serum neuronal protective effects. Lentiviruses knock out of TXNIP and P2X7R was used to determine that protective effects of Naofucong was related to inflammatory response and P2X7/NLRP1/caspase-1 mediated neuronal injury. NAC was also used to inhibit oxidative stress, so as to determine that oxidative stress is an important starting factor for neuronal injury of HT22 cells cultured with high glucose. Naofucong decreased apoptosis, IL-1ß and IL-18 levels in high glucose-induced HT22 hippocampal neuron cells. Naofucong suppressed NLRP1/caspase-1 mediated neuronal injury, and P2X7 was involved in process. HT22 cells cultured in high glucose had an internal environment with elevated oxidative stress, which could promote neuronal injury. The current study demonstrated that Naofucong could significantly improve high glucose-induced HT22 hippocampal neuron injury, which might be related to suppress P2X7R/NLRP1/caspase-1 pathway, which provides novel evidence to support the future clinical use of Naofucong.

Bushen Huoxue Acupuncture Inhibits NLRP1 Inflammasome-Mediated Neuronal Pyroptosis in SAMP8 Mouse Model of Alzheimer's Disease.

BACKGROUND: It was indicated that nucleotide-binding oligomerisation domain­like receptor protein 1 (NLRP1) inflammasome-mediated pyroptosis is involveg in the progression of Alzheimer's disease (AD). This study was designed to explore the effect of Bushen Huoxue Acupuncture on cognitive defect and NLRP1 inflammasome-mediated pyroptosis in AD mouse. METHODS: Senescence-accelerated mouse prone 8 (SAMP8) mice were used as a model of AD. Bushen Huoxue Acupuncture was performed in four acupoints: "Baihui acupoint" (GV20), "Shenshu acupoint" (BL23), "Xuehai acupoint" (SP10), and "Geshu acupoint" (BL17). Morris water maze test was performed to evaluate the cognitive function of the mouse. The levels of Aß1-40, Aß1-42, IL-1ß, and IL-18 were examined by ELISA assay. Neuronal apoptosis and damage in hippocampal tissues were measured using TUNEL and Nissl staining, respectively. The expression of NLRP1, ASC, cleaved caspase-1, IL-1ß, and IL-18 was examined using Western blot. RESULTS: Bushen Huoxue Acupuncture improved the learning and memory deficits of AD mouse. Meanwhile, Bushen Huoxue Acupuncture decreased the production of Aß in hippocampal tissues of SAMP8 mice and attenuated the neuronal apoptosis and damage. Furthermore, Bushen Huoxue Acupuncture inhibited NLRP1 inflammasome activation in SAMP8 mice. CONCLUSION: Bushen Huoxue Acupuncture could notably attenuate the cognitive defect of mouse AD model and inhibit NLRP1 inflammasome-mediated pyroptosis.

Chaihu-Longgu-Muli Decoction exerts an antiepileptic effect in rats by improving pyroptosis in hippocampal neurons.

ETHNOPHARMACOLOGICAL RELEVANCE: Chaihu-Longgu-Muli Decoction (CLMD) is a classic prescription created by Zhong-jing Zhang, a famous ancient Chinese medical scientist, to harmonize uncontrollable body activities and calm the minds. Now Traditional Chinese Medicine (TCM) physicians often apply it to treat psychiatric diseases such as epilepsy. AIM OF THE STUDY: This study investigated the mechanism of the effect of Chaihu-Longgu-Muli Decoction (CLMD) on hippocampal neurons pyroptosis in rats with Temporal Lobe Epilepsy (TLE). MATERIALS AND METHODS: The lithium chloride-pilocarpine-induced TLE rat model was established. The behavioral testing was performed and, the expression of IL-1ß and TNF-α in serum was detected by ELISA, qRT-PCR was used to detect the mRNA expression of NLRP3, Caspase-1, IL-1ß and TNF-α in hippocampus. The expression of NLRP3 and Caspase-1 in hippocampal dentate gyrus was detected by immunofluorescence assay. RESULTS: CLMD could significantly suppress the frequency and duration time of epileptic seizures, reduce the expression of NLRP3, Caspase-1 TNF-α and IL-1ß. CONCLUSIONS: CLMD exerted an obvious antiepileptic effect by improving pyroptosis in hippocampal neurons of TLE rats.

Nao-Fu-Cong ameliorates diabetic cognitive dysfunction by inhibition of JNK/CHOP/Bcl2-mediated apoptosis in vivo and in vitro.

Chinese herbal compound Nao-Fu-Cong (NFC) has been mainly used to treat cognitive disorders in Traditional Chinese Medicine (TCM). The present study aimed to investigate whether its neuroprotective effects might be related to the inhibition of JNK/CHOP/Bcl2-mediated apoptosis pathway or not. We randomly assigned STZ (60 mg·kg-1)-induced diabetic rats into control group, diabetic model group and NFC groups (low-dose, medium-dose and high-dose). The primary culture of hippocampal neurons were transferred into different culture media on the third day. The cells were then divided into control group, high-glucose group, NFC (low-dose, medium-dose and high-dose) groups, CHOP si-RNA intervention group, JNK pathway inhibitor SP600125 group and oxidative stress inhibitor N-acetylcysteine (NAC) group. NFC significantly improved the cognitive function of diabetic rats, and had neuroprotective effect on hippocampal neurons cultured in high glucose. Further research results showed that NFC could reduce the apoptosis of hippocampal neurons in rats with diabetic cognitive dysfunction. NFC had inhibitory effects on CHOP/JNK apoptosis pathway induced by high glucose, and also decreased the levels of ROS and increased the mitochondrial membrane potential. These suggested that the neuroprotective effect of NFC might be related to the inhibition of CHOP and JNK apoptotic signaling pathways, and the cross pathway between oxidative stress and mitochondrial damage pathway.

Saikosaponin d downregulates microRNA-155 and upregulates FGF2 to improve depression-like behaviors in rats induced by unpredictable chronic mild stress by negatively regulating NF-κB.

Saikosaponin d (SSd) is a traditional Chinese medicine that has been widely used in depression treatment. Given the lack of studies demonstrating the underlying mechanism of action of SSd in depression, the presented study was conducted with aims of investigating the effect of SSd on rats with depression-like behaviors induced by unpredicted chronic mild stress (UCMS) and its underlying molecular mechanism. To investigate the effect of SSd on depression, rat models with depression-like behaviors were established through 3-week exposure to UCMS, followed by administration of 10 mg/kg fluoxetine, 0.75 mg/kg SSd, 1.50 mg/kg SSd, or 10 mg/kg caffeic acid phenethyl ester (CAPE). The depression-like behaviors of rats were evaluated by sucrose preference test, open field test, forced swimming test, and tail suspension test. Afterwards, the regulatory relationship among nuclear factor-κB (NF-κB), microRNA (miR)-155 and fibroblast growth factor 2 (FGF2) were detected by dual-luciferase reporter gene assay and ChIP. RT-qPCR and Western blot analysis was conducted to determine the expression of genes and proteins. Finally, hippocampal neurons were extracted from modeled rats and transfected with miR-155 mimic, miR-155 inhibitor, NF-κB overexpression plasmid, or siRNA against NF-κB. The results showed that the depression-like behaviors induced by UCMS in rats was successfully attenuated by SSd. In hippocampal neurons of rats treated with SSd, NF-κB was significantly downregulated while FGF2 was significantly upregulated. NF-κB targets miR-155 and negatively regulates the expression of FGF2. NF-κB knockdown resulted in reduced depression-like behaviors of rats. These findings provide evidence that SSd could ameliorate depression-like behaviors in the rats treated with UCMS by downregulating NF-κB and miR-155, and upregulating FGF2.

Antiepileptic geissoschizine methyl ether is an inhibitor of multiple neuronal channels.

Geissoschizine methyl ether (GM) is an indole alkaloid isolated from Uncaria rhynchophyll (UR) that has been used for the treatment of epilepsy in traditional Chinese medicine. An early study in a glutamate-induced mouse seizure model demonstrated that GM was one of the active ingredients of UR. In this study, electrophysiological technique was used to explore the mechanism underlying the antiepileptic activity of GM. We first showed that GM (1-30 µmol/L) dose-dependently suppressed the spontaneous firing and prolonged the action potential duration in cultured mouse and rat hippocampal neurons. Given the pivotal roles of ion channels in regulating neuronal excitability, we then examined the effects of GM on both voltage-gated and ligand-gated channels in rat hippocampal neurons. We found that GM is an inhibitor of multiple neuronal channels: GM potently inhibited the voltage-gated sodium (NaV), calcium (CaV), and delayed rectifier potassium (IK) currents, and the ligand-gated nicotinic acetylcholine (nACh) currents with IC50 values in the range of 1.3-13.3 µmol/L. In contrast, GM had little effect on the voltage-gated transient outward potassium currents (IA) and four types of ligand-gated channels (γ-amino butyric acid (GABA), N-methyl-D-aspartate (NMDA), α-amino-3-hydroxy-5-methylisoxazole-4-propionate/kainite (AMPA/KA receptors)). The in vivo antiepileptic activity of GM was validated in two electricity-induced seizure models. In the maximal electroshock (MES)-induced mouse seizure model, oral administration of GM (50-100 mg/kg) dose-dependently suppressed generalized tonic-clonic seizures. In 6-Hz-induced mouse seizure model, oral administration of GM (100 mg/kg) reduced treatment-resistant seizures. Thus, we conclude that GM is a promising antiepileptic candidate that inhibits multiple neuronal channels.

Effects and Mechanism of Buyang Huanwu Decoction and the like on Oxygen Deprivation and Reoxygenation of Hippocampal Neurons in Vitro / 中国药学杂志

OBJECTIVE: To investigate the effects and mechanism of Buyang Huanwu Decoction and the like on primary cultured neonate hippocampal neurons induced by oxygen deprivation and reoxygenation. METHODS: The primary cultured hippocampal neurons cell model was established, oxygen sugar deprivation/reoxygenation (OGD/R) model was established in vitro. CCK-8 was used to determine the concentration of Buyang Huanwu Decoction and the like drug-containing serum to protect hippocampal neurons cell. The experimental groups were divided into control group, model group, Buyang Huanwu Decoction drug-containing serum group(10%), Naoxintong Capsule drug-containing serum group(10%), Yangyin Tongnao Granules drug-containing serum group(10%), Buyang Huanwu Decoction drug-containing serum+TAK-242 group(10%,1 μmol•L-1), Naoxintong Capsule drug-containing serum+TAK-242 group(10%,1 μmol•L-1), Yangyin Tongnao Granules drug-containing serum+TAK-242 group(10%,1 μmol•L-1). The morphology of hippocampal neuron was observed under inverted microscope. The expression of tumor necrosis factor-α(TNF-α) and interleukin 1(IL-1β) in the cell supernatant was detected by ELISA kit. The neuronal cell apoptosis was observed by Hoechst 33358 staining fluorescence microscope and the expression of TLR4/NF-κB signaling pathway proteins was detected by Western blot. RESULTS: The results showed that hgher purity neuronal cells can be obtained by primary culture. Compared with model group, Buyang Huanwu Decoction and the like all can reduce the release of TNF-α and IL-1β in hippocampal neurons, significantly reduced the number of apoptosis. At the same time, the three traditional Chinese medicine compounds all can inhibit the expression of TLR4 and NF-κB protein in TLR4/NF-κB signaling pathway, and protect the inflammatory response of oxygenated sugar deprivation and reoxygenated hippocampal neurons. The addition of TLR4-specific inhibitor TAK-242 blocked the conduction of this signaling pathway and reduced the protective effect of Buyang Huanwu Decoction and the like. CONCLUSION: Buyang Huanwu Decoction and the like have protective effects on OGD/R-induced inflammatory response in hippocampal neurons, its mechanism may be related to TLR4/NF-κB signaling pathway, and the anti-inflammatory protective effect of Naoxintong Capsule is relatively obvious.

Nao-Fu-Cong ameliorates diabetic cognitive dysfunction by inhibition of JNK/CHOP/Bcl2-mediated apoptosis in vivo and in vitro / 中国天然药物

Chinese herbal compound Nao-Fu-Cong (NFC) has been mainly used to treat cognitive disorders in Traditional Chinese Medicine (TCM). The present study aimed to investigate whether its neuroprotective effects might be related to the inhibition of JNK/CHOP/Bcl2-mediated apoptosis pathway or not. We randomly assigned STZ (60 mg·kg)-induced diabetic rats into control group, diabetic model group and NFC groups (low-dose, medium-dose and high-dose). The primary culture of hippocampal neurons were transferred into different culture media on the third day. The cells were then divided into control group, high-glucose group, NFC (low-dose, medium-dose and high-dose) groups, CHOP si-RNA intervention group, JNK pathway inhibitor SP600125 group and oxidative stress inhibitor N-acetylcysteine (NAC) group. NFC significantly improved the cognitive function of diabetic rats, and had neuroprotective effect on hippocampal neurons cultured in high glucose. Further research results showed that NFC could reduce the apoptosis of hippocampal neurons in rats with diabetic cognitive dysfunction. NFC had inhibitory effects on CHOP/JNK apoptosis pathway induced by high glucose, and also decreased the levels of ROS and increased the mitochondrial membrane potential. These suggested that the neuroprotective effect of NFC might be related to the inhibition of CHOP and JNK apoptotic signaling pathways, and the cross pathway between oxidative stress and mitochondrial damage pathway.

Dendrobium alkaloids decrease Aß by regulating α- and ß-secretases in hippocampal neurons of SD rats.

BACKGROUND: Alzheimer's disease (AD) is the primary cause of dementia in the elderly. The imbalance between production and clearance of amyloid ß (Aß) is a very early, often initiating factor in AD. Dendrobium nobile Lindl. alkaloids (DNLA) extracted from a Chinese medicinal herb, which have been shown to have anti-aging effects, protected against neuronal impairment in vivo and in vitro. Moreover, we confirmed that DNLA can improve learning and memory function in elderly normal mice, indicating that DNLA has potential health benefits. However, the underlying mechanism is unclear. Therefore, we further explored the effect of DNLA on neurons, which is closely related to learning and memory, based on Aß. METHODS: We exposed cultured hippocampal neurons to DNLA to investigate the effect of DNLA on Aß in vitro. Cell viability was evaluated by MTT assays. Proteins were analyzed by Western blot analysis. RESULTS: The cell viability of hippocampal neurons was not changed significantly after treatment with DNLA. But DNLA reduced the protein expression of amyloid precursor protein (APP), disintegrin and metalloprotease 10 (ADAM10), ß-site APP cleaving enzyme 1 (BACE1) and Aß1-42 of hippocampal neurons in rats and increased the protein expression of ADAM17. CONCLUSIONS: DNLA decreases Aß by regulating α- and ß-secretase in hippocampal neurons of SD rats.

[Protective effect and mechanism of Xiaoyao San on lipopolysaccharide-induced hippocampal neurons injury].

To investigate the relationship between anti-depressant effect and hippocampal nerve growth of Xiaoyao San,the inflammatory model of hippocampal neuron was induced by lipopolysaccharide( LPS). The effect of Xiaoyao San serum( final concentration of4%,8%) on the cell proliferation activity was detected by immunofluorescence,the levels of BDNF and ß-NGF in the supernatant of hippocampal neurons were detected by ELISA,and the expressions of BDNF,NGF,Trk B,Trk A and CREB mRNA in cell lysate of hippocampal neuron were detected by PCR. Western blot was used to detect the expressions of Trk B,CREB,p-CREB and SYP protein in cell lysate of hippocampal neuron,and to reveal the neuroprotective effect and mechanism of Xiaoyao San. The results showed that8% Xiaoyao San serum could significantly increase in Brdu/Neu N ratio( P<0. 01). 4%,8% Xiaoyao San serum could significantly improve the levels of BDNF and ß-NGF in supernatant( P<0. 05 or P<0. 01),up-regulate the expression of BDNF,NGF,Trk B,Trk A,CREB mRNA and Trk B,p-CREB,SYP protein in cell lysate( P< 0. 05 or P< 0. 01). 8% Xiaoyao San serum could significantly increase CREB protein in cell lysate( P<0. 05),and elevate in p-CREB/CREB ratio( P<0. 01). All the above results indicate that Xiaoyao San has a certain protective effect on LPS induced hippocampal neuron injury,which suggests that the protective effect of Xiaoyao San is related to the promotion of hippocampal nerve growth,which is one of its antidepressant mechanisms.

Involvement of the synapse-specific zinc transporter ZnT3 in cadmium-induced hippocampal neurotoxicity.

The present study examined the involvement of zinc (Zn)-transporters (ZnT3) in cadmium (Cd)-induced alterations of Zn homeostasis in rat hippocampal neurons. We treated primary rat hippocampal neurons for 24 or 48 hr with various concentrations of CdCl2 (0, 0.5, 5, 10, 25, or 50 µM) and/or ZnCl 2 (0, 10, 30, 50, 70, or 90 µM), using normal neuronal medium as control. By The CellTiter 96 ® Aqueous One Solution Cell Proliferation Assay (MTS; Promega, Madison, WI) assay and immunohistochemistry for cell death markers, 10 and 25 µM of Cd were found to be noncytotoxic doses, and both 30 and 90 µM of Zn as the best concentrations for cell proliferation. We tested these selected doses. Cd, at concentrations of 10 or 25 µM (and depending on the absence or presence of Zn), decreased the percentage of surviving cells. Cd-induced neuronal death was either apoptotic or necrotic depending on dose, as indicated by 7-AAD and/or annexin V labeling. At the molecular level, Cd exposure induced a decrease in hippocampal brain-derived neurotrophic factor-tropomyosin receptor kinase B (BDNF-TrkB) and Erk1/2 signaling, a significant downregulation of the expression of learning- and memory-related receptors and synaptic proteins such as the NMDAR NR2A subunit and PSD-95, as well as the expression of the synapse-specific vesicular Zn transporter ZnT3 in cultured hippocampal neurons. Zn supplementation, especially at the 30 µM concentration, led to partial or total protection against Cd neurotoxicity both with respect to the number of apoptotic cells and the expression of several genes. Interestingly, after knockdown of ZnT3 by small interfering RNA transfection, we did not find the restoration of the expression of this gene following Zn supplementation at 30 µM concentration. These data indicate the involvement of ZnT3 in the mechanism of Cd-induced hippocampal neurotoxicity.

ADAM22 and ADAM23 modulate the targeting of the Kv1 channel-associated protein LGI1 to the axon initial segment.

The distribution of the voltage-gated Kv1 K+ channels at the axon initial segment (AIS) influences neuronal intrinsic excitability. The Kv1.1 and Kv1.2 (also known as KCNA1 and KCNA2, respectively) subunits are associated with cell adhesion molecules (CAMs), including Caspr2 (also known as CNTNAP2) and LGI1, which are implicated in autoimmune and genetic neurological diseases with seizures. In particular, mutations in the LGI1 gene cause autosomal dominant lateral temporal lobe epilepsy (ADLTE). Here, by using rat hippocampal neurons in culture, we showed that LGI1 is recruited to the AIS where it colocalizes with ADAM22 and Kv1 channels. Strikingly, the missense mutations S473L and R474Q of LGI1 identified in ADLTE prevent its association with ADAM22 and enrichment at the AIS. Moreover, we observed that ADAM22 and ADAM23 modulate the trafficking of LGI1, and promote its ER export and expression at the overall neuronal cell surface. Live-cell imaging indicated that LGI1 is co-transported in axonal vesicles with ADAM22 and ADAM23. Finally, we showed that ADAM22 and ADAM23 also associate with Caspr2 and TAG-1 (also known as CNTN2) to be selectively targeted to different axonal sub-regions. Hence, the combinatorial expression of Kv1-associated CAMs may be critical to tune intrinsic excitability in physiological and epileptogenic contexts.

Icariin Protects Hippocampal Neurons From Endoplasmic Reticulum Stress and NF-κB Mediated Apoptosis in Fetal Rat Hippocampal Neurons and Asthma Rats.

Icariin is a main component of the Chinese medicinal plant Epimedium brevicornu Maxim, exhibits potent activity against inflammatory diseases. Our previous data demonstrated the valid bioactivity of icariin on mitigating rodent asthma. Endoplasmic reticulum (ER) stress and nuclear factor-κB (NF-κB) pathway were involved in the pathogenesis of asthma. However, it remains poorly defined that whether icariin could inhibit ER stress and NF-κB mediated apoptosis in asthma and further influence the central neural system. Herein, we investigated the effects of icariin on primary cultured fetal rat hippocampal neurons and OVALPS-OVA induced asthma rat model. Asthma rat models were established by ovalbumin (OVA) and lipopolysaccharide (LPS) intraperitoneal injection and OVA inhalational challenge. Airway resistance was analyzed to evaluate lung function after last challenge and pathological changes were detected on lung tissues. Assessment of inflammatory cells counts in bronchoalveolar lavage fluids (BALF) were performed and ELISA was used to determine levels of interleukin (IL)-1ß, tumor necrosis factor-α, IL-6, and interferon-γ in serum. Protein expression of BiP and IRE-1α, XBP-1s and phosphorylation-IκBα (p-IκBα), IκBα, and p65 as well as cytochrome c, caspase-3 (cleaved caspase-3), and caspase-9 (cleaved caspase-9) were tested by Western blot. We found that icariin could remarkably improve pulmonary function and reduce inflammatory cells in the lung, levels of inflammatory cytokines, and ER stress related proteins as well as NF-κB were prominently suppressed by icariin. Our results suggested that icariin had an inhibitory effect on airway inflammation and neuroprotective effect on ER stress and NF-κB mediated apoptosis in asthma rats and cultured fetal rat hippocampal neurons, which may provide new mechanistic insights into the asthma prevention and treatment of icariin.

Protective effect and mechanism of Xiaoyao San on lipopolysaccharide-induced hippocampal neurons injury / 中国中药杂志

To investigate the relationship between anti-depressant effect and hippocampal nerve growth of Xiaoyao San,the inflammatory model of hippocampal neuron was induced by lipopolysaccharide( LPS). The effect of Xiaoyao San serum( final concentration of4%,8%) on the cell proliferation activity was detected by immunofluorescence,the levels of BDNF and β-NGF in the supernatant of hippocampal neurons were detected by ELISA,and the expressions of BDNF,NGF,Trk B,Trk A and CREB mRNA in cell lysate of hippocampal neuron were detected by PCR. Western blot was used to detect the expressions of Trk B,CREB,p-CREB and SYP protein in cell lysate of hippocampal neuron,and to reveal the neuroprotective effect and mechanism of Xiaoyao San. The results showed that8% Xiaoyao San serum could significantly increase in Brdu/Neu N ratio( P<0. 01). 4%,8% Xiaoyao San serum could significantly improve the levels of BDNF and β-NGF in supernatant( P<0. 05 or P<0. 01),up-regulate the expression of BDNF,NGF,Trk B,Trk A,CREB mRNA and Trk B,p-CREB,SYP protein in cell lysate( P< 0. 05 or P< 0. 01). 8% Xiaoyao San serum could significantly increase CREB protein in cell lysate( P<0. 05),and elevate in p-CREB/CREB ratio( P<0. 01). All the above results indicate that Xiaoyao San has a certain protective effect on LPS induced hippocampal neuron injury,which suggests that the protective effect of Xiaoyao San is related to the promotion of hippocampal nerve growth,which is one of its antidepressant mechanisms.

Effect of medicated thread moxibustion on apoptosis of hippocampal neurons in rat models of chronic cerebral ischemic vascular dementia.

To investigate the effect of medicated thread moxibustion onapoptosis in hippocampal neuronsin a rat model of chronic cerebral ischemic vascular dementia. A total of 40 male Wistar rats were randomly divided into normal group and sham-operated group (7 rats each), and rat model of chronic cerebral ischemic vascular dementia (14 rats). The model group rats were treated with medicated thread moxibustion two weeks after surgery, once a day, with one day break every six days, (24 times in all)and an observation period of 4 weeks. At the end of therapy, H&E staining was used to monitor changes in the neurons in CA1 area of the rat hippocampus. Changes in related indexes such as Bax, Bc1-2 and C-fos of neuron apoptosis in hippocampus CA1 area were determined by immunohistochemistry, while protein expression was semi-quantitatively assayed using imaging analysis technique. There was significant hippocampal neuronal necrosis six weeks after model establishment, but the necrosis was milder in rats in the medicated thread moxibustion group. Bax and C-fos were positively expressed and significantly higher in the hippocampus of chronic cerebral ischemic vascular dementia rats (model group) than in the medicated thread moxibustion group after treatment (p <0.01). The expression of Bcl-2 was increased in the medicated thread group after treatment, and was higher in the model group, but comparable to that in the sham-operated group (p=0.975>0.05). Medicated thread moxibustion alleviates hippocampal neuronal necrosis, inhibits neuron apoptosis in hippocampus CA1 area, protects nerves, and maintains relative equilibrium inBax/Bcl-2 through down-regulation of C-fos and Bax and up-regulation of Bcl-2. Thus, cell apoptosis-related pathway may be one of its mechanisms of action.