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*

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

The MAPK signaling pathway plays a key role in the differentiation, proliferation and apoptosis of cells, and its family members mainly include extracellular signal-regulated kinase (ERK), stress-activated protein kinase (JNK), and p38 mitogen-activated protein kinase (p38MAPK). Recent studies have shown that the ERK, JNK and p38MAPK signaling pathways are closely associated with the development and progression of erectile dysfunction (ED). This review focuses on the correlation between the MAPK signaling pathway and ED.
Apoptosis ; Cell Differentiation ; Cell Proliferation ; Erectile Dysfunction ; etiology ; metabolism ; Humans ; JNK Mitogen-Activated Protein Kinases ; metabolism ; MAP Kinase Signaling System ; Male ; Mitogen-Activated Protein Kinases ; metabolism ; Signal Transduction ; p38 Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVETo explore the mechanisms of neuroprotective effects of c-Jun N-terminal kinase (JNK)/FOXO3a transcription factor signaling pathway inhibition on hypoxic-ischemic neuronal apoptosis in neonatal rats with hypoxic-ischemic brain damage (HIBD).

METHODSSixty-four 7-day-old Sprague-Dawley rats were divided into four groups: hypoxia-ischemia (HI), sham-operated, JNK specific inhibitor AS601245-treated, and DMSO vehicle. Rats' cerebral cortexes were collected at 24 hours after HI. Western blot was used to detect the protein expression of JNK, p-JNK, FOXO3a, nuclear and cytoplasmic FOXO3a, Bim, and CC3. TUNEL staining was used to detect the apoptotic cells.

RESULTSCompared with the sham-operated group, p-JNK protein increased (P<0.01), nuclear protein of FOXO3a increased (P<0.01), cytoplasmic protein decreased (P<0.01), and pro-apoptotic proteins Bim and CC3 increased 24 hours after HI (P<0.01). Compared with the HI and DMSO vehicle groups, p-JNK protein was reduced (P<0.01), nuclear protein of FOXO3a was also reduced (P<0.01), cytoplasmic protein increased (P<0.01), and Bim and CC3 proteins decreased (P<0.01) in the AS601245-treated group 24 hours after HI. TUNEL positive cells were reduced in the AS601245-treated rats compared with the HI and DMSO vehicle groups 24 hours after HI (P<0.01).

CONCLUSIONSJNK activity increases in the neonatal rat brain with HI damage. JNK activity inhibition can inhibit FOXO3a translocation from cytoplasm to nucleus and downregulate the levels of pro-apoptotic proteins Bim and CC3, leading to the reduction of neuronal apoptosis.

Active Transport, Cell Nucleus ; Animals ; Animals, Newborn ; Apoptosis ; Cell Nucleus ; metabolism ; Female ; Forkhead Box Protein O3 ; metabolism ; Hypoxia-Ischemia, Brain ; pathology ; JNK Mitogen-Activated Protein Kinases ; physiology ; Male ; Neurons ; pathology ; Rats ; Rats, Sprague-Dawley

Objective: To investigate the expressions of JNK and p-JNK in advanced prostate cancer (PCa) and benign prostatic hyperplasia (BPH) and their implications. METHODS: Using immunohistochemistry, we detected the expressions of JNK and p-JNK proteins in 40 cases of paraffin wax-embedded PCa and 21 cases of BPH tissues and analyzed their relationships with advanced PCa and BPH as well as with the pathologic features of advanced PCa. RESULTS: Statistically significant differences were not found in the positive expression rate of the JNK protein between BPH and PCa (42.86% vs 52.50%, P>0.05), non-metastatic and metastatic PCa (53.85% vs 51.85%, P >0.05), Gleason ≤7 and Gleason >7 (58.82% vs 47.82%, P >0.05), PSA ≤20 μg/L and PSA >20 μg/L (57.14% vs 51.52%, P >0.05), or survival >5 yr and survival ≤5 yr (60.00% vs 45.00%, P >0.05), nor in the expression level of p-JNK between BPH and PCa (33.33% vs 35.00%, P >0.05), non-metastatic and metastatic PCa (30.77% vs 37.03%, P >0.05), Gleason ≤7 and Gleason >7 (35.29% vs 34.78%, P >0.05), or PSA ≤20 μg/L and PSA >20 μg/L (43.75% vs 10.93%, P >0.05). However, the expression of p-JNK was significantly higher in the survival >5 yr than in the survival ≤5 yr group of the PCa patients (50.00% vs 20.00%, P <0.05). CONCLUSIONS PCa patients with highly expressed p-JNK have a longer survival time and the high positive rate of p-JNK is associated with the prognosis of PCa.
Humans ; Immunohistochemistry ; JNK Mitogen-Activated Protein Kinases ; metabolism ; Male ; Neoplasm Grading ; Neoplasm Proteins ; metabolism ; Prognosis ; Prostate-Specific Antigen ; metabolism ; Prostatic Hyperplasia ; enzymology ; mortality ; pathology ; Prostatic Neoplasms ; enzymology ; mortality ; pathology

BACKGROUND/AIMS: We investigated whether angiotensin III (Ang III) is involved in monocyte recruitment through regulation of the chemokine monocyte chemoattractant protein-1 (MCP-1) in cultured human proximal tubular epithelial cells (HK-2 cells). METHODS: We measured MCP-1 levels in HK-2 cells that had been treated with various concentrations of Ang III and Ang II type-1 (AT1) receptor antagonists at various time points. The phosphorylation states of p38, c-Jun N-terminal kinases (JNK), and extracellular-signal-regulated kinases were measured in Ang III-treated cells to explore the mitogen-activated protein kinase (MAPK) pathway. MCP-1 levels in HK-2 cell-conditioned media were measured after pre-treatment with the transcription factor inhibitors curcumin or pyrrolidine dithiocarbamate. RESULTS: Ang III increased MCP-1 protein production in dose- and time-dependent manners in HK-2 cells, which was inhibited by the AT1 receptor blocker losartan. p38 MAPK activity increased significantly in HK-2 cells exposed to Ang III for 30 minutes, and was sustained at higher levels after 60 minutes (p < 0.05). Total phosphorylated JNK protein levels tended to increase 20 minutes after stimulation with Ang III. Pre-treatment with a p38 inhibitor, a JNK inhibitor, or curcumin significantly inhibited Ang III-induced MCP-1 production. CONCLUSIONS: Ang III increases MCP-1 synthesis via stimulation of intracellular p38 and JNK MAPK signaling activity and subsequent activated protein-1 transcriptional activity in HK-2 cells.
Angiotensin II Type 1 Receptor Blockers/pharmacology ; Angiotensin III/*pharmacology ; Cell Line ; Chemokine CCL2/*metabolism ; Dose-Response Relationship, Drug ; Epithelial Cells/*drug effects/metabolism ; Humans ; JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors/metabolism ; Kidney Tubules, Proximal/*drug effects/metabolism ; Phosphorylation ; Protein Kinase Inhibitors/pharmacology ; Signal Transduction/drug effects ; Time Factors ; Transcription Factor AP-1/metabolism ; Up-Regulation ; p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors/metabolism

The epithelial cytokine response, associated with reactive oxygen species (ROS), is important in Helicobacter pylori (H. pylori)-induced inflammation. H. pylori induces the production of ROS, which may be involved in the activation of mitogen-activated protein kinases (MAPK), janus kinase/signal transducers and activators of transcription (Jak/Stat), and oxidant-sensitive transcription factor, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB), and thus, expression of interleukin-8 (IL-8) in gastric epithelial cells. alpha-lipoic acid, a naturally occurring thiol compound, is a potential antioxidant. It shows beneficial effects in treatment of oxidant-associated diseases including diabetes. The present study is purposed to investigate whether alpha-lipoic acid inhibits expression of inflammatory cytokine IL-8 by suppressing activation of MAPK, Jak/Stat, and NF-kappaB in H. pylori-infected gastric epithelial cells. Gastric epithelial AGS cells were pretreated with or without alpha-lipoic acid for 2 h and infected with H. pylori in a Korean isolate (HP99) at a ratio of 300:1. IL-8 mRNA expression was analyzed by RT-PCR analysis. IL-8 levels in the medium were determined by enzyme-linked immunosorbent assay. NF-kappaB-DNA binding activity was determined by electrophoretic mobility shift assay. Phospho-specific and total forms of MAPK and Jak/Stat were assessed by Western blot analysis. ROS levels were determined using dichlorofluorescein fluorescence. As a result, H. pylori induced increases in ROS levels, mRNA, and protein levels of IL-8, as well as the activation of MAPK [extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase 1/2 (JNK1/2), p38], Jak/Stat (Jak1/2, Stat3), and NF-kappaB in AGS cells, which was inhibited by alpha-lipoic acid. In conclusion, alpha-lipoic acid may be beneficial for prevention and/or treatment of H. pylori infection-associated gastric inflammation.
Enzyme-Linked Immunosorbent Assay ; Epithelial Cells/metabolism ; Gastric Mucosa/*drug effects/metabolism/microbiology ; Gene Expression Regulation, Bacterial ; Helicobacter Infections/immunology/*metabolism ; Helicobacter pylori/drug effects/*pathogenicity ; Humans ; Interleukin-8/genetics/*metabolism ; JNK Mitogen-Activated Protein Kinases ; Janus Kinase 1 ; Mitogen-Activated Protein Kinases/*biosynthesis ; NF-kappa B/*metabolism ; RNA, Messenger/isolation & purification/metabolism ; Reactive Oxygen Species/metabolism ; STAT3 Transcription Factor ; Stomach/metabolism/*microbiology ; Thioctic Acid/*pharmacology

BACKGROUNDAn acute respiratory distress syndrome (ARDS) is still one of the major challenges in critically ill patients. This study aimed to investigate the effect of inhibiting c-Jun N-terminal kinase (JNK) on ARDS in a lipopolysaccharide (LPS)-induced ARDS rat model.

METHODSThirty-six rats were randomized into three groups: control, LPS, and LPS + JNK inhibitor. Rats were sacrificed 8 h after LPS treatment. The lung edema was observed by measuring the wet-to-dry weight (W/D) ratio of the lung. The severity of pulmonary inflammation was observed by measuring myeloperoxidase (MPO) activity of lung tissue. Moreover, the neutrophils in bronchoalveolar lavage fluid (BALF) were counted to observe the airway inflammation. In addition, lung collagen accumulation was quantified by Sircol Collagen Assay. At the same time, the pulmonary histologic examination was performed, and lung injury score was achieved in all three groups.

RESULTSMPO activity in lung tissue was found increased in rats treated with LPS comparing with that in control (1.26 ± 0.15 U in LPS vs. 0.77 ± 0.27 U in control, P < 0.05). Inhibiting JNK attenuated LPS-induced MPO activity upregulation (0.52 ± 0.12 U in LPS + JNK inhibitor vs. 1.26 ± 0.15 U in LPS, P < 0.05). Neutrophils in BALF were also found to be increased with LPS treatment, and inhibiting JNK attenuated LPS-induced neutrophils increase in BALF (255.0 ± 164.4 in LPS vs. 53 (44.5-103) in control vs. 127.0 ± 44.3 in LPS + JNK inhibitor, P < 0.05). At the same time, the lung injury score showed a reduction in LPS + JNK inhibitor group comparing with that in LPS group (13.42 ± 4.82 vs. 7.00 ± 1.83, P = 0.001). However, the lung W/D ratio and the collagen in BALF did not show any differences between LPS and LPS + JNK inhibitor group.

CONCLUSIONSInhibiting JNK alleviated LPS-induced acute lung inflammation and had no effects on pulmonary edema and fibrosis. JNK inhibitor might be a potential therapeutic medication in ARDS, in the context of reducing lung inflammatory.

Animals ; Anthracenes ; therapeutic use ; Collagen ; metabolism ; JNK Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; metabolism ; Lipopolysaccharides ; toxicity ; Lung ; drug effects ; metabolism ; pathology ; Male ; Rats ; Respiratory Distress Syndrome, Adult ; chemically induced ; drug therapy ; Signal Transduction ; drug effects