The aim of this study is to explore the mechanism of ligustilide, the main active constituent of essential oils of traditional Chinese medicine Angelicae Sinensis Radix, on alleviating oxygen-glucose deprivation/reperfusion(OGD/R) injury in PC12 cells from the perspective of ferroptosis. OGD/R was induced in vitro, and 12 h after ligustilide addition during reperfusion, cell viability was detected by cell counting kit-8(CCK-8) assay. DCFH-DA staining was used to detect the level of intracellular reactive oxygen species(ROS). Western blot was employed to detect the expression of ferroptosis-related proteins, glutathione peroxidase 4(GPX4), transferrin receptor 1(TFR1), and solute carrier family 7 member 11(SLC7A11), and ferritinophagy-related proteins, nuclear receptor coactivator 4(NCOA4), ferritin heavy chain 1(FTH1), and microtubule-associated protein 1 light chain 3(LC3). The fluorescence intensity of LC3 protein was analyzed by immunofluorescence staining. The content of glutathione(GSH), malondialdehyde(MDA), and Fe was detected by chemiluminescent immunoassay. The effect of ligustilide on ferroptosis was observed by overexpression of NCOA4 gene. The results showed that ligustilide increased the viability of PC12 cells damaged by OGD/R, inhibited the release of ROS, reduced the content of Fe and MDA and the expression of TFR1, NCOA4, and LC3, and improved the content of GSH and the expression of GPX4, SLC7A11, and FTH1 compared with OGD/R group. After overexpression of the key protein NCOA4 in ferritinophagy, the inhibitory effect of ligustilide on ferroptosis was partially reversed, indicating that ligustilide may alleviate OGD/R injury of PC12 cells by blocking ferritinophagy and then inhibiting ferroptosis. The mechanism by which ligustilide reduced OGD/R injury in PC12 cells is that it suppressed the ferroptosis involved in ferritinophagy.
Animals ; Rats ; PC12 Cells ; Ferroptosis/genetics* ; Reactive Oxygen Species ; Transcription Factors ; Glutathione

Objective: To investigate the effect and mechanism of miR-96-5p on apoptosis of PC12 cells induced by maltol aluminum. Methods: In January 2021, PC12 cells at logarithmic growth phase were divided into blank control group and low, medium and high dose group. Cells in each group were treated with 0, 100, 200 and 400 μmol/L maltol aluminum for 24 hours respectively. Cells were collected and cell apoptosis rates were detected by flow cytometry, miR-96-5p and insulin receptor substrate 1 (IRS1) mRNA expressions were detected by qRT-PCR, and the protein expression levels of cysteine protease 3 (Caspase3) 、activated cysteine protease 3 (Cleaved-caspase3) 、IRS1、phosphorylated protein kinase B (p-AKT) and phosphorylated glucose synthesis kinase 3β (p-GSK3β) were detected by western blotting. The target binding relationship between miR-96-5p and IRS1 was detected by double luciferase reporter gene experiment. The miR-96-5p inhibitor cells and negative control cells were constructed after transfecting PC12 cells with miR-96-5p inhibitor for 24 hours. The cells were divided into blank control group, negative control group, aluminum exposure group, aluminum exposure+negative control group, aluminum exposure+miR-96-5p inhibition group, and miR-96-5p inhibition group. After transfecting PC12 cells with miR-96-5p inhibition and IRS1 siRNA for 24 h, the cells were divided into aluminum exposure+miR-96-5p inhibition+negative control group and aluminum exposure+miR-96-5p inhibition+IRS1 inhibition group. The control group was cultured in complete culture medium, and cells in the aluminum exposure group were treated with 200 μmol/L maltol aluminum for 24 hours. Cells in each group were collected and the apoptosis rate, miR-96-5p and IRS1 mRNA expression levels, as well as protein expression levels of Caspase3, Cleaved-caspase3, IRS1, p-AKT, and p-GSK3β were measured. Results: After 24 hours of exposure, compared with blank control group and low-dose group, the apoptosis rates, relative expressions of Caspase3 and Cleaved-caspase3 proteins, and relative expressions of miR-96-5p in the medium and high-dose groups of PC12 cells were significantly increased, while the relative expression levels of IRS1 mRNA, IRS1, p-AKT and p-GSK3β proteins were significantly decreased (P<0.05). Targetscan prediction and double luciferase report experiment both proved that IRS1 was a direct target gene of miR-96-5p. In the transfection experiment, compared with the aluminum exposure group, the apoptosis rate, the relative expressions of Caspase3 and Cleaved-caspase3 proteins, the relative expression of miR-96-5p in the aluminum exposure+miR-96-5p inhibition group were significantly decreased, while the relative expression levels of IRS1 mRNA and IRS1, p-AKT and p-GSK3β proteins were significantly increased (P<0.05). In the IRS1 low expression experiment, compared with the aluminum exposure+miR-96-5p inhibition+negative control group, the apoptosis rate, the relative expressions of Caspase3 and Cleaved-caspase3 proteins in the aluminum exposure+miR-96-5p inhibition+IRS1 inhibition group were significantly increased, while the relative expression levels of IRS1 mRNA and IRS1, p-AKT and p-GSK3β proteins were significantly decreased (P<0.05) . Conclusion: The increased expression of miR-96-5p and the targeted inhibition of IRS1 may be one of the mechanisms of apoptosis of PC12 cells induced by maltol aluminum exposure.
Animals ; Rats ; Aluminum/toxicity* ; Apoptosis ; Cell Proliferation ; Glycogen Synthase Kinase 3 beta/metabolism* ; Insulin Receptor Substrate Proteins/metabolism* ; MicroRNAs/metabolism* ; PC12 Cells ; Proto-Oncogene Proteins c-akt/metabolism* ; RNA, Messenger

Rats ; Animals ; Okadaic Acid/toxicity* ; PC12 Cells ; Triterpenes ; tau Proteins/metabolism* ; Phosphorylation

Animals ; Rats ; Neuroprotective Agents/pharmacology* ; Amyloid beta-Peptides ; PC12 Cells ; Polyunsaturated Alkamides/pharmacology* ; Apoptosis ; Cell Survival ; Peptide Fragments

This study explored the protective effect of astragaloside Ⅳ(AS-Ⅳ) on oxygen-glucose deprivation(OGD)-induced autophagic injury in PC12 cells and its underlying mechanism. An OGD-induced autophagic injury model in vitro was established in PC12 cells. The cells were divided into a normal group, an OGD group, low-, medium-, and high-dose AS-Ⅳ groups, and a positive drug dexmedetomidine(DEX) group. Cell viability was measured using the MTT assay. Transmission electron microscopy was used to observe autophagosomes and autolysosomes, and the MDC staining method was used to assess the fluorescence intensity of autophagosomes. Western blot was conducted to determine the relative expression levels of functional proteins LC3-Ⅱ/LC3-Ⅰ, Beclin1, p-Akt/Akt, p-mTOR/mTOR, and HIF-1α. Compared with the normal group, the OGD group exhibited a significant decrease in cell viability(P<0.01), an increase in autophagosomes(P<0.01), enhanced fluorescence intensity of autophagosomes(P<0.01), up-regulated Beclin1, LC3-Ⅱ/LC3-Ⅰ, and HIF-1α(P<0.05 or P<0.01), and down-regulated p-Akt/Akt and p-mTOR/mTOR(P<0.05 or P<0.01). Compared with the OGD group, the low-and medium-dose AS-Ⅳ groups and the DEX group showed a significant increase in cell viability(P<0.01), decreased autophagosomes(P<0.01), weakened fluorescence intensity of autophagosomes(P<0.01), down-regulated Beclin1, LC3-Ⅱ/LC3-Ⅰ, and HIF-1α(P<0.05 or P<0.01), and up-regulated p-Akt/Akt and p-mTOR/mTOR(P<0.01). AS-Ⅳ at low and medium doses exerted a protective effect against OGD-induced autophagic injury in PC12 cells by activating the Akt/mTOR pathway, subsequently influencing HIF-1α. The high-dose AS-Ⅳ group did not show a statistically significant difference compared with the OGD group. This study provides a certain target reference for the prevention and treatment of OGD-induced cellular autophagic injury by AS-Ⅳ and accumulates laboratory data for the secondary development of Astragali Radix and AS-Ⅳ.
Rats ; Animals ; PC12 Cells ; Proto-Oncogene Proteins c-akt/genetics* ; Glucose/therapeutic use* ; Oxygen/metabolism* ; Beclin-1/pharmacology* ; TOR Serine-Threonine Kinases/metabolism* ; Autophagy ; Apoptosis ; Reperfusion Injury/drug therapy*

Objective: A gradient stress model of PC12 cells induced by corticosterone was established to provide a basis for the evaluation and regulation of cell stress. Methods: The effect of corticosterone on cell viability was observed by measuring PC12 cell viability at different concentrations of corticosterone (0~1 000 μmol/L) after different intervention times (8~48 h) to screen the cell models for optimal intervention conditions. Key stress indicators (MDA, SOD, NADH, LDH) were measured spectrophotometrically and microscopically to evaluate the models. Results: When the concentration of corticosterone was below 200 μmol/L and the intervention time was 12 h, the cell viability was below half inactivation rate, which could reduce the confounding factors due to the decrease of cell viability in each group. Compared with the blank control group, corticosterone increased the levels of MDA, NADH and LDH,and decreased the levels of SOD in the model group in a concentration-dependent manner (P＜0.01), which was consistent with the construction of the gradient stress model. Conclusion: A gradient stress injury model of PC12 cells was successfully established, with intervention concentrations of 0 μmol/L, 25 μmol/L, 50 μmol/L, 100 μmol/L, 150 μmol/L and 200 μmol/L corticosterone at an intervention time of 12 h. The degree of stress injury of the cell model was increased gradually, which could be used as a basis and object for conducting cell stress injury assessment and regulation experiments.
Animals ; Cell Survival ; Corticosterone/pharmacology* ; NAD/pharmacology* ; PC12 Cells ; Rats ; Superoxide Dismutase

Five new polycyclic polyprenylated acylphloroglucinols (1-5), ascyrones A-E, and four known compounds (6-9) were isolated from the aerial parts of Hypericum ascyron. All of the isolates containing a bicyclo[3.3.1]nonane-2,4,9-trione core and a benzoyl group, belonged to type B bicyclic polyprenylated acylphloroglucinols (BPAPs). Their structures and absolute configurations were established based on spectroscopic analyses and calculated electronic circular dichroism (ECD) data. The anti-inflammatory, neuroprotective and cytotoxicity activities of compounds 1-4 and 6-9 were evaluated. Compound 6 exhibited obvious anti-inflammatory activity in lipopolysaccharide (LPS)-induced RAW264.7 cells. Compounds 1 and 9 exhibited slight cytotoxicity against Hep3B cells. Meanwhile, compound 1 showed mild neuroprotective activity against corticosterone (CORT)-induced PC12 cell damage at 10 μmol·L^-1.
Animals ; Anti-Inflammatory Agents/pharmacology* ; Hypericum/chemistry* ; Molecular Structure ; PC12 Cells ; Phloroglucinol/pharmacology* ; Rats

Amyloid β-protein(Aβ) deposition in the brain is directly responsible for neuronal mitochondrial damage of Alzheimer's disease(AD) patients. Mitophagy, which removes damaged mitochondria, is a vital mode of neuron protection. Ginsenoside Rg_1(Rg_1), with neuroprotective effect, has displayed promising potential for AD treatment. However, the mechanism underlying the neuroprotective effect of Rg_1 has not been fully elucidated. The present study investigated the effects of ginsenoside Rg_(1 )on the autophagy of PC12 cells injured by Aβ_(25-35) to gain insight into the neuroprotective mechanism of Rg_1. The autophagy inducer rapamycin and the autophagy inhi-bitor chloroquine were used to verify the correlation between the neuroprotective effect of Rg_1 and autophagy. The results showed that Rg_1 enhanced the viability and increased the mitochondrial membrane potential of Aβ-injured PC12 cells, while these changes were blocked by chloroquine. Furthermore, Rg_(1 )treatment increased the LC3Ⅱ/Ⅰ protein ratio, promoted the depletion of p62 protein, up-regulated the protein levels of PINK1 and parkin, and reduced the amount of autophagy adaptor OPTN, which indicated the enhancement of autophagy. After the silencing of PINK1, a key regulatory site of mitophagy, Rg_1 could not increase the expression of PINK1 and parkin or the amount of NDP52, whereas it can still increase the LC3Ⅱ/Ⅰ protein ratio and promote the depletion of OPTN protein which indicated the enhancement of autophagy. Collectively, the results of this study imply that Rg_1 can promote autophagy of PC12 cells injured by Aβ, and may reduce Aβ-induced mitochondrial damage by promoting PINK1-dependent mitophagy, which may be one of the key mechanisms of its neuroprotective effect.
Amyloid beta-Peptides/toxicity* ; Animals ; Ginsenosides/pharmacology* ; Humans ; Mitophagy/physiology* ; PC12 Cells ; Protein Kinases/metabolism* ; Rats ; Ubiquitin-Protein Ligases/metabolism*

In this study, the molecular mechanism of astragaloside Ⅳ(AS-Ⅳ) in the treatment of Parkinson's disease(PD) was explored based on network pharmacology, and the potential value of AS-Ⅳ in alleviating neuronal injury in PD by activating the PI3 K/AKT signaling pathway was verified through molecular docking and in vitro experiments. Such databases as SwissTargetPrediction, BTMAN-TAM, and GeneCards were used to predict the targets of AS-Ⅳ for the treatment of PD. The Search Tool for the Retrieval of Interacting Genes/Proteins(STRING) was employed to analyze protein-protein interaction(PPI) and construct a PPI network, and the Database for Annotation, Visualization and Integrated Discovery(DAVID) was used for Gene Ontology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis. Based on the results of GO enrichment analysis and KEGG pathway analysis, the PI3 K/AKT signaling pathway was selected for further molecular docking and in vitro experiments in this study. The in vitro cell model of PD was established by MPP~+. The cell viability was measured by MTT assay and effect of AS-Ⅳ on the expression of the PI3 K/AKT signaling pathway-related genes and proteins by real-time polymerase chain reaction(RT-PCR) and Western blot. Network pharmacology revealed totally 122 targets of AS-Ⅳ for the treatment of PD, and GO enrichment analysis yielded 504 GO terms, most of which were biological processes and molecular functions. Totally 20 related signaling pathways were screened out by KEGG pathway analysis, including neuroactive ligand-receptor interaction, PI3 K/AKT signaling pathway, GABAergic synapse, and calcium signaling pathway. Molecular docking demonstrated high affinity of AS-Ⅳ to serine/threonine-protein kinases(AKT1, AKT2), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit gamma(PIK3 CG), and phosphoinositide-3-kinase, catalytic, alpha polypeptide(PIK3 CA) on the PI3 K/AKT signaling pathway. In vitro experiments showed that AS-Ⅳ could effectively inhibit the decrease of the viability of PC12 induced by MPP~+ and up-regulate the mRNA expression levels of AKT1 and PI3 K as well as the phosphorylation levels of AKT and PI3 K. As an active component of Astragali Radix, AS-Ⅳ acts on PD through multiple targets and pathways. Furthermore, it inhibits neuronal apoptosis and protects neurons by activating the PI3 K/AKT signaling pathway, thereby providing reliable theoretical and experimental supports for the treatment of PD with AS-Ⅳ.
Animals ; Drugs, Chinese Herbal/pharmacology* ; Molecular Docking Simulation ; Network Pharmacology ; PC12 Cells ; Phosphatidylinositol 3-Kinases/genetics* ; Proto-Oncogene Proteins c-akt/genetics* ; Rats ; Saponins ; Signal Transduction ; Triterpenes

To construct a hypobaric hypoxia-induced cell injury model. Rat pheochromocytoma PC12 cells were randomly divided into control group, normobaric hypoxia group and hypobaric hypoxia group. The cells in control group were cultured at normal condition, while cells in other two groups were cultured in normobaric hypoxia and hypobaric hypoxia conditions, respectively. CCK-8 method was used to detect cell viability to determine the optimal modeling conditions like the oxygen concentration, atmospheric pressure and low-pressure hypoxia time. The contents of lactate dehydrogenase (LDH), superoxide dismutase (SOD) and malondialdehyde (MDA) were detected by microplate method. The apoptosis ratio and cell cycle were analyzed by flow cytometry. The hypobaric hypoxia-induced cell injury model can be established by culturing for 24 h at 1% oxygen concentration and 41 kPa atmospheric pressure. Compared with the control group and normobaric hypoxia group, the activity of LDH and the content of MDA in hypobaric hypoxia group were significantly increased, the activity of SOD was decreased, the percentage of apoptosis was increased (all <0.05), and the cell cycle was arrested in G0/G1 phase. A stable and reliable cell injury model induced by hypobaric hypoxia has been established with PC12 cells, which provides a suitable cell model for the experimental study on nerve injury induced by hypoxia at high altitude.
Animals ; Cell Hypoxia ; Hypoxia ; Malondialdehyde ; PC12 Cells ; Rats ; Superoxide Dismutase/metabolism*