Acetaminophen (APAP) is the most common antipyretic, analgesic and anti-inflammatory drug, but its overdose often leads to acute liver injury, even acute liver failure, and death in some severe cases. At present, there is still a lack of specific treatments. The c-Jun N-terminal kinase (JNK) signal pathway is one of the potential therapeutic targets identified in recent years in overdose APAP-induced acute liver injury. This article reviews the JNK signaling pathway of APAP in liver metabolism, the activation of JNK signaling pathway and the amplification of oxidative stress, other pathways or cellular processes related to JNK signaling pathway, and the possible challenges of drugs targeting JNK, so as to provide direction and feasibility analysis for further research and clinical application of JNK signaling pathway targets in APAP hepatotoxicity, and to provide reference for searching for other targets.
Animals ; Mice ; Acetaminophen/adverse effects* ; Chemical and Drug Induced Liver Injury ; Chemical and Drug Induced Liver Injury, Chronic/metabolism* ; JNK Mitogen-Activated Protein Kinases/metabolism* ; Liver ; Mice, Inbred C57BL ; Signal Transduction

Objective: To investigate the effect and underlying mechanism of paeoniflorin on hippocampal neuron apoptosis induced by lead acetate. Methods: In September 2020, primary hippocampal neuronal cells were isolated and cultured from fetal rats, and identified using cellular immunofluorescent. MTT assay was used to measure the cell viability to determine the concentration and time of lead acetate-induced hippocampal neuron apoptosis. MTT was also used to evaluate the effect of paeoniflorin concentration on the apoptosis of hippocampal neurons induced by lead acetate. According to the results, different concentrations of paeoniflorin were selected to intervene hippocampal neuron cells, after 24 h, lead acetate was added to the cells, meanwhile, blank and model groups were set up, the content of reactive oxygen species (ROS) , superoxide dismutase (SOD) , lactate dehydrogenase (LDH) , malondialdehyde (MDA) and Caspase-3 were measured. Extracellular signal regulated kinase (ERK) , phosphorylated ERK (p-ERK) , p38 mitogen -activated protein kinases (p38MAPK) , phosphorylated p38MAPK (p-p38MAPK) , c-Jun N-terminal kinase (JNK) and phosphorylated JNK (p-JNK) protein expression in hippocampal neuronal cells were determined by Western blotting. Results: The isolated and cultured hippocampal neurons were identified by immunofluorescence chemical staining and then treated with lead acetate, MTT results showed that lead acetate had the best toxicity effect when treated for 24 h at a concentration of 25 μmol/L. Paeoniflorin showed no cytotoxic effect on hippocampal neuronal cells when the concentrations below 80 μmol/L. Compared with the model group, the activity of hippocampal neuronal cells was significantly increased after treating with 20, 40 or 80 μmol/L paeoniflorin (P<0.05) . Compared with the blank group, the ROS activity, LDH release level, MDA content and caspase-3 content were significantly increased (P<0.01) , and the SOD activity was significantly decreased (P< 0.01) in the hippocampal neuronal cells of the model group. Compared with the model group, the ROS activity, LDH release level, MDA content and caspase-3 content were obviously decreased (P<0.05) , SOD activity was significantly increased (P <0.01) after hippocampal neuronal cells were treated with 40 or 80 μmol/L paeoniflorin. Relative to the model group, the ratio of p-ERK/ERK were significantly up-regulated (P<0.01) , while the ratios of p-p38MAPK/p38MAPK and p-JNK/JNK were significantly down-regulated after hippocampal neuronal cells were treated with 40 or 80 μmol/L paeoniflorin (P<0.05) . Conclusion: Paeoniflorin may down-regulate the expression of p-p38MAPK and p-JNK protein, up-regulate the expression of p-ERK protein, and inhibit the apoptosis of hippocampal neurons induced by lead acetate through the MAPK signaling pathway.
Acetates/pharmacology* ; Animals ; Apoptosis ; Caspase 3/metabolism* ; Extracellular Signal-Regulated MAP Kinases/metabolism* ; Glucosides ; Hippocampus/metabolism* ; JNK Mitogen-Activated Protein Kinases/pharmacology* ; Lead ; Monoterpenes ; Neurons/metabolism* ; Rats ; Reactive Oxygen Species/metabolism* ; Superoxide Dismutase/metabolism* ; p38 Mitogen-Activated Protein Kinases/metabolism*

To assess the () recombinant gingivalis gingipain R2 (rRgpB)-induced Ca mobilization in human gingival fibroblast (HGF) mediated by protease-activated receptor (PAR) and its downstream signal transduction pathways. : Flow cytometry was used to detect the expression of PAR in HGF. The proliferation of HGF was measured by CCK-8. The dynamic changes of intracellular Ca concentration in HGF induced by rRgpB and the blocking effect of PAR-1 antagonist were observed by laser confocal microscopy. Western blot was performed to determine the phosphorylation levels of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) 1/2, p38 mitogen-activated protein kinase (p38 MAPK) and p65 in HGF. : PAR-1 and PAR-3 were expressed in HGF, and the rRgpB could promote the proliferation of HGF. rRgpB caused a transient increase in [Ca], which could be completely suppressed by vorapaxar, a PAR-1 antagonist. The phosphorylation levels of JNK, ERK1/2 and p65 were significantly up-regulated after the induction of rRgpB for and (all <0.05), which was completely inhibited by vorapaxar. However, the phosphorylation level of p38 MAPK had no significant change after rRgpB stimulation. : rRgpB causes an increase in [Ca] in HGF mediated by PAR-1. JNK, ERK1/2 and nuclear factor-κB may be involved in intracellular signal transduction after PAR-1 activation.
Fibroblasts ; Humans ; JNK Mitogen-Activated Protein Kinases/metabolism* ; MAP Kinase Signaling System ; Phosphorylation ; Signal Transduction ; p38 Mitogen-Activated Protein Kinases/metabolism*

BACKGROUND: The primary aims of periodontal disease treatment is to remove dental plaque and calculus, the main causes of tooth loss, and restore periodontal tissue destroyed by inflammation. Periodontal disease treatment should also help maintain the alveolar bone, alleviate inflammation, and promote periodontal ligament cell proliferation, which is essential for tissue regeneration. Conventional antibiotics and anti-inflammatories have adverse side effects, especially during long-term use, so there is a need for adjunct treatment agents derived from natural products. The purpose of this study was to investigate whether the herbal flavone baicalein has the osteogenic activity under inflammatory conditions, and assess the involvement of osteoblast immediate early response 3 (IER3) expression.METHODS: Human osteoblastic MG-63 cells were cultured with the pro-inflammatory cytokines tumor necrosis factor α and interleukin 1β in the presence and absence of baicalein. Proliferation was assessed using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, and expression of IER3 mRNA was assessed using real-time polymerase chain reaction. The expression of IER3 protein levels and activation of associated signal transduction pathways were assessed using western blotting.RESULTS: Baicalein increased IER3 mRNA and protein expression synergistically. In addition, baicalein reversed the suppression of cell proliferation, and the downregulation of osteogenic transcription factor runt-related transcription factor 2 and osterix induced by pro-inflammatory cytokines. Baicalein also upregulated the phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK 1/2). The upregulation of IER3 by pro-inflammatory cytokines was blocked by pretreatment with inhibitors of AKT, p38, JNK, and ERK 1/2.CONCLUSION: Baicalein mitigates the deleterious responses of osteoblasts to pro-inflammatory cytokines. Further, IER3 enhanced the effect of baicalein via activation of AKT, p38, JNK, and ERK pathways.
Anti-Bacterial Agents ; Anti-Inflammatory Agents ; Biological Products ; Blotting, Western ; Calculi ; Cell Proliferation ; Cytokines ; Dental Plaque ; Down-Regulation ; Humans ; Inflammation ; Interleukins ; JNK Mitogen-Activated Protein Kinases ; MAP Kinase Signaling System ; Osteoblasts ; Osteogenesis ; Periodontal Diseases ; Periodontal Ligament ; Phosphorylation ; Phosphotransferases ; Real-Time Polymerase Chain Reaction ; Regeneration ; RNA, Messenger ; Signal Transduction ; Tooth Loss ; Transcription Factors ; Tumor Necrosis Factor-alpha ; Up-Regulation

To explore the effect of propofol on human cardiac AC16 cells under CoCl2-induced hypoxic injury and the possible mechanisms.
 Methods: Human AC16 cardiomyocytes were treated with cobalt chloride (CoCl2) to mimic hypoxic condition in cultured cardiomyocytes. The AC16 cells were divided into 3 groups: a control group, a CoCl2 hypoxia group (CoCl2 group), and a propofol+CoCl2 group (propofol+ CoCl2 group). The cell viability was assessed by cell counting kit-8 (CCK-8). Cell apoptosis ratio (AR) and the mitochondrial membrane potential (Δψm) were detected by flow cytometry. The reactive oxygen species (ROS) production in AC16 cells were determined with the ROS-sensitive fluorescent probe. Meanwhile, total intracellular levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in AC16 cells were detected with commercially available kits. Western blot was used to evaluate the activation of c-Jun N-terminal kinase (JNK) and p38 signaling pathways.
 Results: 1) Compared with the control group, AC16 cell viability was decreased significantly in the CoCl2 group following the treatment with 500 μmol/L CoCl2 (P<0.01); 2) Compared with the control group, AR value in AC16 cells was increased significantly in the CoCl2 group, while Δψm was decreased significantly (all P<0.01). Compared with the CoCl2 group, AR value in AC16 cells was decreased significantly in the propofol+CoCl2 group, while Δψm was increased significantly (both P<0.05); 3) Compared with the control group, the levels of ROS and MDA were increased significantly, and the level of SOD was significantly decreased in the CoCl2 group (all P<0.01). Compared with the CoCl2 group, the ROS and MDA levels in the propofol+CoCl2 group were increased significantly and the SOD levels were decreased significantly (all P<0.05); 4) Compared with the control group, the phosphorylation levels of JNK and p38 were increased significantly (both P<0.05) in the CoCl2 group. Compared with the CoCl2 group, the phosphorylation levels of JNK and p38 were decreased significantly in the propofol+CoCl2 group (both P<0.05).
 Conclusion: The pretreatment with propofol may protect human cardiac AC16 cells from the chemical hypoxia-induced injury through regulation of JNK and p38 signaling pathways.
Apoptosis ; Cell Hypoxia ; Cell Line ; Cell Survival ; Cobalt ; pharmacology ; Humans ; Hypoxia ; JNK Mitogen-Activated Protein Kinases ; Propofol ; Reactive Oxygen Species

Mannosylerythritol lipids (MELs) are glycolipids and have several pharmacological efficacies. MELs also show skin-moisturizing efficacy through a yet-unknown underlying mechanism. Aquaporin-3 (AQP3) is a membrane protein that contributes to the water homeostasis of the epidermis, and decreased AQP3 expression following ultraviolet (UV)-irradiation of the skin is associated with reduced skin moisture. No previous study has examined whether the skin-moisturizing effect of MELs might act through the modulation of AQP3 expression. Here, we report for the first time that MELs ameliorate the UVA-induced downregulation of AQP3 in cultured human epidermal keratinocytes (HaCaT keratinocytes). Our results revealed that UVA irradiation decreases AQP3 expression at the protein and messenger RNA (mRNA) levels, but that MEL treatment significantly ameliorated these effects. Our mitogen-activated protein kinase inhibitor analysis revealed that phosphorylation of c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase or p38, mediates UVA-induced AQP3 downregulation, and that MEL treatment significantly suppressed the UVA-induced phosphorylation of JNK. To explore a possible mechanism, we tested whether MELs could regulate the expression of peroxidase proliferator-activated receptor gamma (PPAR-γ), which acts as a potent transcription factor for AQP3 expression. Interestingly, UVA irradiation significantly inhibited the mRNA expression of PPAR-γ in HaCaT keratinocytes, whereas a JNK inhibitor and MELs significantly rescued this effect. Taken together, these findings suggest that MELs ameliorate UVA-induced AQP3 downregulation in HaCaT keratinocytes by suppressing JNK activation to block the decrease of PPAR-γ. Collectively, our findings suggest that MELs can be used as a potential ingredient that modulates AQP3 expression to improve skin moisturization following UVA irradiation-induced damage.
Down-Regulation* ; Epidermis ; Glycolipids ; Homeostasis ; Humans* ; JNK Mitogen-Activated Protein Kinases* ; Keratinocytes* ; Membrane Proteins ; Peroxidase ; Phosphorylation* ; Phosphotransferases ; PPAR gamma ; Protein Kinases ; RNA, Messenger ; Skin ; Transcription Factors ; Water

OBJECTIVE: To investigate the effects of myeloid differentiation-2 (MD2) gene silencing on high glucose-induced proliferation inhibition, apoptosis and inflammation in rat cardiomyocytes. METHODS: The immortalized rat cardiomyocyte cell line H9C2 were transfected with MD2 small interfering RNA (si-MD2) and negative control for 24 h, then stimulated with high glucose (HG) for 48 h. RT-qPCR was performed to detect the mRNA levels of MD2 and inflammatory factors TNF-α, IL-1β and IL-6. MTS and flow cytometry were used to evaluate cell proliferation, cell cycle and apoptosis rate. Western blot was used to detect protein expression levels and phosphorylation levels. RESULTS: The mRNA and protein levels of MD2 in H9C2 cells were dramatically decreased after transfected with si-MD2 (P＜0.01). After stimulation of high glucose, the mRNA levels of inflammatory factors, the cells in G0/G1 phase , the cell apoptosis rate and the protein level of cleaved Caspase-3 were significantly increased, while the cell proliferation ability was decreased (P＜0.01). MD2 gene silencing antagonized the effects of high glucose on cell proliferation, cell cycle, cell apoptosis and the mRNA levels of TNF-α, IL-1β , IL-6(P＜0.05). Western blot analysis showed that the phosphorylation levels of extracellular signal-regulated kinase(ERK1/2), P38 mitogen-activated protein kinase(P38 MAPK) and C-Jun N-terminal kinase(JNK) protein were increased significantly in H9C2 cells treated with high glucose, which could be reversed by silencing of MD2 (P＜0.01). CONCLUSION This study demonstrates that MD2 gene silencing reverses high glucose-induced myocardial inflammation, apoptosis and proliferation inhibition via the mechanisms involving suppression of ERK, P38 MAPK, JNK signaling pathway.
Animals ; Apoptosis ; Cell Proliferation ; Cells, Cultured ; Cytokines ; metabolism ; Gene Silencing ; Glucose ; Inflammation ; JNK Mitogen-Activated Protein Kinases ; metabolism ; Lymphocyte Antigen 96 ; genetics ; Myocytes, Cardiac ; cytology ; Rats ; p38 Mitogen-Activated Protein Kinases ; metabolism

BACKGROUND/AIMS: This study aimed to determine the regulatory role of N-acetyl-l-cysteine (NAC), an antioxidant, in interleukin 17 (IL-17)-induced osteoclast differentiation in rheumatoid arthritis (RA). METHODS: After RA synovial fibroblasts were stimulated by IL-17, the expression and production of receptor activator of nuclear factor κ-B ligand (RANKL) was determined by real-time polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA). Osteoclastogenesis was also determined after co-cultures of IL-17-stimulated RA synovial fibroblasts, Th17 cells and various concentrations of NAC with monocytes. After human peripheral CD4⁺ T cells were cultured with NAC under Th17 condition, IL-17, interferon γ, IL-4, Foxp3, RANKL, and IL-2 expression and production was determined by flow cytometry or ELISA. RESULTS: When RA synovial fibroblasts were stimulated by IL-17, IL-17 stimulated the production of RANKL, and NAC reduced the IL-17-induced RANKL production in a dose-dependent manner. NAC decreased IL-17-activated phosphorylation of mammalian target of rapamycin, c-Jun N-terminal kinase, and inhibitor of κB. When human peripheral blood CD14⁺ monocytes were cultured with macrophage colony-stimulating factor and IL-17 or RANKL, osteoclasts were differentiated, and NAC reduced the osteoclastogenesis. After human peripheral CD4⁺ T cells were co-cultured with IL-17-pretreated RA synovial fibroblasts or Th17 cells, NAC reduced their osteoclastogenesis. Under Th17 polarizing condition, NAC decreased Th17 cell differentiation and IL-17 and RANKL production. CONCLUSIONS: NAC inhibits the IL-17-induced RANKL production in RA synovial fibroblasts and IL-17-induced osteoclast differentiation. NAC also reduced Th17 polarization. NAC could be a supplementary therapeutic option for inflammatory and bony destructive processes in RA.
Acetylcysteine* ; Arthritis, Rheumatoid* ; Coculture Techniques ; Enzyme-Linked Immunosorbent Assay ; Fibroblasts ; Flow Cytometry ; Humans ; Interferons ; Interleukin-17 ; Interleukin-2 ; Interleukin-4 ; JNK Mitogen-Activated Protein Kinases ; Macrophage Colony-Stimulating Factor ; Monocytes ; Osteoclasts ; Osteogenesis ; Phosphorylation ; RANK Ligand ; Real-Time Polymerase Chain Reaction ; Sirolimus ; T-Lymphocytes ; Th17 Cells

Cyclosporin A (CsA) does not only exert a toxic effect on kidney parenchymal cells, but also protects them against necrotic cell death by inhibiting opening of mitochondrial permeability transition pore. However, whether CsA plays a role in hydrogen peroxide-induced kidney proximal tubular cell death is currently unclear. In the present study, treatment with CsA further increased apoptosis and necrosis in HK-2 human kidney proximal tubule epithelial cells during exposure to hydrogen peroxide. In addition, hydrogen peroxide-induced p53 activation and BH3 interacting-domain death agonist (BID) expression were higher in CsA-treated cells than those in non-treated cells, whereas hydrogen peroxide-induced activation of mitogen-activated protein kinases including p38, c-Jun N-terminal kinase, and extracellular signal-regulated kinase and activation of protein kinase B were not significantly altered by treatment with CsA. In oxidant-antioxidant system, reactive oxygen species (ROS) production induced by hydrogen peroxide was further enhanced by treatment with CsA. However, expression levels of antioxidant enzymes including manganese superoxide dismutase, copper/zinc superoxide dismutase, and catalase were not altered by treatment with hydrogen peroxide or CsA. Treatment with CsA further enhanced mitochondrial membrane potential induced by exposure to hydrogen peroxide, although it did not alter endoplasmic reticulum stress based on expression of glucose-regulated protein 78 and 94. Taken together, these data suggest that CsA can aggravate hydrogen peroxide-induced cell death through p53 activation, BID expression, and ROS production.
Apoptosis ; Catalase ; Cell Death ; Cyclosporine ; Endoplasmic Reticulum Stress ; Epithelial Cells ; Humans ; Hydrogen Peroxide ; Hydrogen ; JNK Mitogen-Activated Protein Kinases ; Kidney ; Membrane Potential, Mitochondrial ; Mitogen-Activated Protein Kinases ; Necrosis ; Permeability ; Phosphotransferases ; Proto-Oncogene Proteins c-akt ; Reactive Oxygen Species ; Superoxide Dismutase

Daidzein isolated from soybean (Glycine max) has been widely studied for its antioxidant and anti-inflammatory activities. However, the protective effects of 7,8,4′-trihydroxyisoflavone (THIF), a major metabolite of daidzein, on 6-hydroxydopamine (OHDA)-induced neurotoxicity are not well understood. In the current study, 7,8,4′-THIF significantly inhibited neuronal cell death and lactate dehydrogenase (LDH) release induced by 6-OHDA in SH-SY5Y cells, which were used as an in vitro model of Parkinson's disease (PD). Moreover, pretreatment with 7,8,4′-THIF significantly increased the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) and decreased malondialdehyde (MDA) activity in 6-OHDA-induced SH-SY5Y cells. In addition, 7,8,4′-THIF significantly recovered 6-OHDA-induced cleaved caspase-3, cleaved caspase-9, cleaved poly-ADP-ribose polymerase (PARP), increased Bax, and decreased Bcl-2 levels. Additionally, 7,8,4′-THIF significantly restored the expression levels of phosphorylated c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase 1/2 (ERK 1/2), phosphatidylinositol 3-kinases (PI3K)/Akt, and glycogen synthase kinase-3 beta (GSK-3β) in 6-OHDA-induced SH-SY5Y cells. Further, 7,8,4′-THIF significantly increased the reduced tyrosine hydroxylase (TH) level induced by 6-OHDA in SH-SY5Y cells. Collectively, these results suggest that 7,8,4′-THIF protects against 6-OHDA-induced neuronal cell death in cellular PD models. Also, these effects are mediated partly by inhibiting activation of the MAPK and PI3K/Akt/GSK-3β pathways.
Apoptosis ; Caspase 3 ; Caspase 9 ; Catalase ; Cell Death ; Glutathione ; Glycogen Synthase ; In Vitro Techniques ; JNK Mitogen-Activated Protein Kinases ; L-Lactate Dehydrogenase ; Malondialdehyde ; Neurons ; Oxidopamine ; Parkinson Disease ; Phosphatidylinositol 3-Kinases ; Phosphotransferases ; Protein Kinases ; Soybeans ; Superoxide Dismutase ; Tyrosine 3-Monooxygenase