Cell Viability Of Hippocampal Neurons Research Articles

JZL184 protects hippocampal neurons from oxygen-glucose deprivation-induced injury via activating Nrf2/ARE signaling pathway.

JZL184 is a selective inhibitor of monoacylglycerol lipase (MAGL) that has neuroprotective effect. However, the role of JZL184 in cerebral ischemia/reperfusion (I/R) injury and the exact mechanism have not been fully understood. This study was designed to elucidate the role of JZL184 in cerebral I/R injury induced by oxygen-glucose deprivation/reoxygenation (OGD/R) in hippocampal neurons. Hippocampal neurons were pretreated with various concentrations of JZL184 for 2 h, followed by OGD for 3 h and reoxygen for 24 h. Our results showed that JZL184 improved cell viability in hippocampal neurons in response to OGD/R. JZL184 treatment significantly inhibited the production of reactive oxygen species (ROS) and malondialdehyde (MDA), as well as increased superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in OGD/R-induced hippocampal neurons. The increased TNF-α, IL-1β, and IL-6 productions in OGD/R-induced hippocampal neurons were decreased after treatment with JZL184. Moreover, the OGD/R-caused intense TUNEL staining in hippocampal neurons was attenuated by JZL184. JZL184 treatment prevented OGD/R-caused increases in bax and cleaved caspase-3 expression and a decrease in bcl-2 expression. Furthermore, JZL184 treatment significantly promoted the activation of Nrf2/ARE signaling pathway in OGD/R-induced hippocampal neurons. Additionally, silencing of Nrf2 reversed the protective effect of JZL184 on hippocampal neurons under OGD/R condition. Taken together, these findings suggested that JZL184 exerted protective effect against OGD/R-induced injury in hippocampal neurons via activating Nrf2/ARE signaling pathway, which provided in vitro experimental support for the therapeutic benefit of JZL184 in cerebral ischemia.

Effects of propofol on hippocampal neuron viability.

In this study, we investigated the effects of different concentration of propofol on cell viability of hippocampal neurons and explored the possible mechanism. Primary hippocampal neurons were cultured in vitro and treated with different concentration of propofol. MTT was used to examine the survival of neurons. Flow cytometry was used to detect the neuronal apoptosis. Western-blot analysis was used to examine the expression level of p-p38MAPK and p38MAPK. We found that low concentration propofol (0.5μM and 1μM) promoted the cell survival rate; however, high concentration of propofol (10μM,50μM,100μM,150μM, and 200μM) decreased the cell survival rate (P < 0.05). Flow cytometry showed that the neuronal apoptosis rate was decreased in 1μM propofol group (P < 0.05), but was significantly higher in10μM, 100μM and 200μM groups in a concentration-dependent manner (P < 0.05 or P < 0.01). Western blot revealed that the propofol induced the phosphorylation of p38MAPK concentration-dependently and time-dependently. SB203580, one inhibitor of p38MAPK, increased the cell survival rate and decreased the cell apoptosis induced by high concentration of propofol. Low concentration of propofol improved the survival rate of neurons, while high concentration of propofol promoted the cell apoptosis and decreased the cell viability. p38MAPK pathway is involved the effect of high concentration of propofol promoted on primary hippocampal neurons viability and apoptosis.

Taraxasterol protects hippocampal neurons from oxygen-glucose deprivation-induced injury through activation of Nrf2 signalling pathway

Cerebral ischemia/reperfusion (I/R) injury is a brain injury following ischaemic stroke that is associated with oxidative stress. Taraxasterol, a natural product, has been shown to have anti-oxidative and neuro-protective effects. However, the role of taraxasterol in cerebral I/R injury remains unknown. Primary hippocampal neurons were subjected to oxygen-glucose deprivation/reperfusion (OGD/R) to induce cerebral I/R injury in vitro. Cell viability of hippocampal neurons was measured CCK-8 assay. Reactive oxygen species (ROS) production and MDA generation were measured to reflect oxidative stress. Western blotting was performed to evaluate the expressions of bax, bcl-2, NF-E2-related factor 2 (Nrf2), haem oxygenase (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO-1) and GPx-3. Caspase-3 activity was measured to assess cell apoptosis. Hippocampal neurons were treated with ML385 to inhibit Nrf2 signalling pathway. Our results showed that taraxasterol improved OGD/R-caused decrease in cell viability of hippocampal neurons. In addition, taraxasterol significantly suppressed ROS production and MDA generation in OGD/R-induced hippocampal neurons. Taraxasterol resulted in a significant decrease in caspase-3 activity and bcl-2 expression, as well as increase in bax expression. Furthermore, taraxasterol induced the Nrf2 nuclear accumulation and expressions of HO-1, NQO-1 and GPx-3 in OGD/R-induced hippocampal neurons. Notably, inhibition of Nrf2 signalling reversed the protective effects of taraxasterol on OGD/R-induced hippocampal neurons injury. In conclusion, these findings indicated that taraxasterol protected hippocampal neurons from OGD/R-induced oxidative stress and cell apoptosis via regulating the Nrf2 signalling pathway.

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

BackgroundAlzheimer’s disease (AD) is the primary cause of dementia in the elderly. The imbalance between production and clearance of amyloid β (Aβ) 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 Aβ.MethodsWe exposed cultured hippocampal neurons to DNLA to investigate the effect of DNLA on Aβ in vitro. Cell viability was evaluated by MTT assays. Proteins were analyzed by Western blot analysis.ResultsThe 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), β-site APP cleaving enzyme 1 (BACE1) and Aβ1–42 of hippocampal neurons in rats and increased the protein expression of ADAM17.ConclusionsDNLA decreases Aβ by regulating α- and β-secretase in hippocampal neurons of SD rats.

Emodin attenuates Alzheimer's disease by activating the protein kinase C signaling pathway

To investigate the effects of emodin on learning and memory and protein kinase C (PKC) signaling pathway in Alzheimer's disease (AD) model mice. 60 APP/PS1 double transgenic AD mice were selected as model mice at the age of 7-8 months, 36 healthy male C57BL/6 mice served as the control group. Morris water maze method and passive avoidance experiment were used to evaluate the memory ability of mice. The thiazole blue (MTT) method and the lactate dehydrogenase (LDH) cytotoxicity test kit were used to evaluate the effect of emodin on the cell viability of hippocampal neurons in HT22 mice treated with β-amyloid peptide 1-42 (Aβ1-42). The effect of emodin on PKC levels was explored using the modified Takai method and Western blotting. Behavioral test results showed that the escape latency of the mice in the model group was longer than that in the control group (P&lt;0.05), and the escape latency was significantly shortened given a emodin prognosis. The MTT and LDH test results showed that emodin to Aβ- overexpression induced the protective effect of hippocampus cells in HT22 mice. Western blot analysis showed that the phosphorylation level of PKC in mice increased significantly after emodin administration. Emodin can attenuate oxidative stress and inflammatory response in Alzheimer's model mice by activating PKC pathway, thereby improving cognitive function.

Scoparone protects neuronal cells from oxygen glucose deprivation/reoxygenation injury.

Ischemic stroke is one of the leading causes of death and disability in the world. The cerebral ischemia/reperfusion (I/R) injury is considered as the major molecular mechanism in the pathogenesis of ischemic stroke. Scoparone, a major constituent of Artemisia capillaries, has been found to exhibit protective effects against I/R-induced myocardial injury. However, the role of scoparone in cerebral I/R injury has not been elucidated. In the current study, the hippocampal neurons were subjected to oxygen-glucose deprivation/reperfusion (OGD/R) to simulate I/R injury in vitro. The results showed that scoparone improved OGD/R-induced inhibitory effect on cell viability of hippocampal neurons. Scoparone displayed anti-oxidative activity as proved by the decreased levels of reactive oxygen species (ROS) and malondialdehyde (MDA), and increased activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in OGD/R-induced hippocampal neurons. In addition, cell apoptosis was markedly decreased after scoparone treatment in OGD/R-induced hippocampal neurons. The expression of bax was significantly decreased, while bcl-2 expression was increased in the scoparone pretreated hippocampal neurons. Furthermore, the expressions of nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were obviously induced by scoparone. Knockdown of Nrf2 by siRNA transfection dramatically attenuated the protective effects of scoparone on OGD/R-induced hippocampal neurons. Collectively, scoparone protected hippocampal neurons from OGD/R-induced injury via activating Nrf2/HO-1 signaling pathway, suggesting that scoparone might be a potential agent for the ischemic stroke therapy.

Effect of different concentration of propofol on cell viability and apoptosis in hippocampal neurons of fetal rats

Objective To investigate the effect of different concentration of propofol on cell viability in hippocampal neurons of fetal rats in vitro.Methods Primary cultured hippocampal neurons were prepared from the fetuses of Sprague-Dawley rats after 17 d-18 d of gestation,and cultured for 7 d,immunocytochemical method was used to identify the cultured neurons.① The neurons were randomly divided into 12 groups (n=5):control group (group C) received no treatment,in group D 0.1％ dimethyl sulfoxide (DMSO) was added,in group P1-10 propofol was added at the final concentration of 0.01,0.1,0.5,1,5,10,50,100,150 μmol/L and 200 μmol/L respectively.The cells were selected after 24 h incubation for detection of the cell survival rate by cell viability[3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay].② The neurons were randomly divided into 7 groups(n=5):control group (group C) received no treatment,in group D 0.1％ DMSO was added,in group PⅠ,Ⅱ,Ⅲ,v,v propofol was added at the final concentration of 0.1,1,10,100 μmol/L and 200 μmol/L respectively.The cells were selected after 24 h incubation for detection of the neuronal apoptosis by immunofluorescence staining and flow cytometry.Results ① There was no significantly difference in the cell survival rate between group C and D (P＞0.05).Compared with group D,the cell survival rate was no significantly difference in group P1,2,5(P＞0.05),the cell survival rate was significantly increased in group P3(102.2±2.7)％,P4(102.9±2.7)％(P＜0.05) and that was significantly lower in group P6-10 in a concentration-dependent manner by (97.0±3.5)％,(90.1 ± 1.7)％,(79.8±0.9)％,(67.9± 1.1)％,(42.3±2.2)％ respectively (P＜0.05 or P＜0.01).② There was no significantly difference in the neuronal apoptosis rate between group C and D (P＞0.05).Compared with group D,the neuronal apoptosis rate was no significantly difference in group PⅠ (P＞0.05),the neuronal apoptosis rate was significantly decreased in group PⅡ (P＜0.05) and that was significantly higher in group PⅢ,Ⅳ,Ⅴ in a concentration-dependent manner by (8.2±0.8)％,(18.1±1.1)％,(29.1±2.1)％ respectively(P＜0.05 or P＜0.01).Conclusions The effect of propofol on cell viability and apoptosis in hippocampal neurons was bidirectional,propofol at the concentration of 1 μmol/L can inhibit the apoptosis and improve the survival rate of neurons,while decrease the cell viability through promoting the cell apoptosis in a concentration-dependent manner at the concentration of 10,100 μmol/L and 200 μmol/L. Key words: Propofol; Hippocampal neuron; Cell viability; Apoptosis

In vitro biocompatibility of chitosan-based materials to primary culture of hippocampal neurons

The natural biomaterial chitosan has been widely used as a promising nerve guidance conduit material for peripheral nerve repair. This study aimed to investigate in vitro biocompatibility of chitosan to primarily cultured hippocampal neurons, one type of central nervous system (CNS) cells. The substrate made up of chitosan fibers or membranes was found to support the survival and growth of the attached hippocampal neurons by using light and electron microscopy as well as immunocytochemistry for neurofilament 200, growth-associated protein-43, microtubule-associated protein 2, beta-tubulin III and synaptophysin. MTT assay indicated that the cell viability of hippocampal neurons in chitosan fiber or membrane extract was not significantly different from that in hydroxyapatite extract or plain neuronal medium, but significantly higher than that in organotin extract after culture for different times. Western analysis revealed that no significant difference in the protein level of growth-associated protein-43 and beta-tubulin III was detected between hippocampal neurons cultured in chitosan extract and in plain neuronal culture medium. The results collectively demonstrate that chitosan is biocompatible to primary culture of hippocampal neurons without cytotoxic effects on cell phenotype and functions, raising a potential possibility of using chitosan for CNS therapy.