Selenomethionine alleviates LPS-induced JNK/NLRP3 inflammasome-dependent necroptosis by modulating miR-15a and oxidative stress in chicken lungs.

Selenium (Se) was involved in many physiological processes in humans and animals. microRNAs (miRNAs) also played important roles in lung diseases. However, the regulatory mechanism of miRNA in chicken lungs and the mechanism of lipopolysaccharide (LPS)-induced pneumonia remained unclear. To further study these mechanisms, we established a supplement of selenomethionine (SeMet) and/or LPS-treated chicken model and a cell model of LPS and/or high and low expression of miR-15a in chicken hepatocellular carcinoma (LMH) cells. We detected the expression of some selenoproteins, p-c-Jun N-terminal kinase (JNK), nod-like receptor protein 3 (NLRP3), caspase1, receptor-interacting serine-threonine kinase 1 (RIPK1), receptor-interacting serine-threonine kinase 3 (RIPK3), mixed lineage kinase domain-like pseudokinase (MLKL), miR-15a, and oxidative stress kits. Additionally, we observed the morphology of lungs by H.E. staining in vitro. The results indicated that necroptosis occurred in LPS-treated chicken and LMH cells. Moreover, LPS stimulation inhibited miR-15a, and increased the expression of JNK, NLRP3, caspase1, RIPK1, RIPK3, and MLKL. We also found that LPS treatment not only increased the content of H2O2 and MDA in the lungs but also increased the activities of iNOS and CAT and the content of GSH decreased. Conclusion: SeMet could reduce the oxidative damage and activate NLRP3 inflammasome reaction by stimulating miR-15a/JNK, thus reduced the pulmonary necroptosis induced by LPS.

A Dual Target-Directed Single Domain-Based Fusion Protein Against Interleukin-6 Receptor Decelerate Experimental Arthritis Progression Via Modulating JNK Expression.

The currently used anti-cytokine therapeutic antibodies cannot selectively neutralize pathogenic cytokine signalling that cause collateral damage to protective signalling cascades. The single domain chain firstly discovered in Camelidae displays fully functional ability in antigen-binding against variable targets, which has been seemed as attractive candidates for the next-generation biologic drug study. In this study, we established a simple prokaryotic expression system for a dual target-directed single domain-based fusion protein against the interleukin-6 receptor and human serum, albumin, the recombinant anti-IL-6R fusion protein (VHH-0031). VHH-0031 exhibited potent anti-inflammatory effects produced by LPS on cell RAW264.7, where the major cytokines and NO production were downregulated after 24 h incubation with VHH-0031 in a dose-dependent manner. In vivo, VHH-0031 presented significant effects on the degree reduction of joint swelling in the adjuvant-induced arthritis (AIA) rat, having a healthier appearance compared with the dexamethasone. The expression level of JNK protein in the VHH-0031 group was significantly decreased, demonstrating that VHH-0031 provides a low-cost and desirable effect in the treatment of more widely patients.

Secoiridoid Glucosides and Anti-Inflammatory Constituents from the Stem Bark of Fraxinus chinensis.

Qin Pi (Fraxinus chinensis Roxb.) is commercially used in healthcare products for the improvement of intestinal function and gouty arthritis in many countries. Three new secoiridoid glucosides, (8E)-4''-O-methylligstroside (1), (8E)-4''-O-methyldemethylligstroside (2), and 3'',4''-di-O-methyl-demethyloleuropein (3), have been isolated from the stem bark of Fraxinus chinensis, together with 23 known compounds (4-26). The structures of the new compounds were established by spectroscopic analyses (1D, 2D NMR, IR, UV, and HRESIMS). Among the isolated compounds, (8E)-4''-O-methylligstroside (1), (8E)-4''-O-methyldemethylligstroside (2), 3'',4''-di-O-methyldemethyloleuropein (3), oleuropein (6), aesculetin (9), isoscopoletin (11), aesculetin dimethyl ester (12), fraxetin (14), tyrosol (21), 4-hydroxyphenethyl acetate (22), and (+)-pinoresinol (24) exhibited inhibition (IC50 ≤ 7.65 µg/mL) of superoxide anion generation by human neutrophils in response to formyl-L-methionyl-L-leuckyl-L-phenylalanine/cytochalasin B (fMLP/CB). Compounds 1, 9, 11, 14, 21, and 22 inhibited fMLP/CB-induced elastase release with IC50 ≤ 3.23 µg/mL. In addition, compounds 2, 9, 11, 14, and 21 showed potent inhibition with IC50 values ≤ 27.11 µM, against lipopolysaccharide (LPS)-induced nitric oxide (NO) generation. The well-known proinflammatory cytokines, tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6), were also inhibited by compounds 1, 9, and 14. Compounds 1, 9, and 14 displayed an anti-inflammatory effect against NO, TNF-α, and IL-6 through the inhibition of activation of MAPKs and IκBα in LPS-activated macrophages. In addition, compounds 1, 9, and 14 stimulated anti-inflammatory M2 phenotype by elevating the expression of arginase 1 and Krüppel-like factor 4 (KLF4). The above results suggested that compounds 1, 9, and 14 could be considered as potential compounds for further development of NO production-targeted anti-inflammatory agents.

Anti-cancer potential of persimmon (Diospyros kaki) leaves via the PDGFR-Rac-JNK pathway.

Persimmon leaves are known to have some beneficial effects, including ROS elimination, lipid circulation, and neuronal protection. However, their anti-cancer properties and the underlying mechanisms remain unclear. Herein, we show that treatment with the ethanol extract of persimmon, Diospyros kaki, leaves (EEDK) induces cancer cell death and inhibits cell proliferation. Using fluorescence resonance energy transfer (FRET) technology with genetically-encoded biosensors, we first found that EEDK stimulates a PDGFR-Rac signaling cascade in live cells. Moreover, we found that downstream of the PDGFR-Rac pathway, JNKs are activated by EEDK. In contrast, JNK-downstream inhibitors, such as CoCl2, T-5224, and pepstatin A, attenuated EEDK-induced cell death. Thus, we illustrate that the PDGFR-Rac-JNK signaling axis is triggered by EEDK, leading to cancer cell death, suggesting the extract of persimmon leaves may be a promising anti-cancer agent.

Hepatotoxic Effect of Oral Zinc Oxide Nanoparticles and the Ameliorating Role of Selenium in Rats: A histological, immunohistochemical and molecular study.

Despite the emerging concerns about the hepatotoxic risks associated with Zinc oxide nanoparticles (ZnO NPs), yet, the morphological and molecular alterations associated with these extensively-used nanoparticles remain to be elucidated. Thus, the current study has been designed to analyze the effect of ZnO NPs on the hepatic histopathological and immunohistochemical changes, along with the modulation of the oxidative-stress induced JNK/p38MAPK and the STAT-3 signalling. The study also explored the potential protective role of selenium against those alterations. ZnO NPs disrupted the hepatic architecture, elevated the serum liver enzyme alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) levels and caused dose-dependent decrease in the activity of the antioxidant enzymes glutathione-peroxidase, superoxide dismutase and catalase along with an increase in the lipid peroxidation product malondialdehyde. ZnO NPs also increased the area of immune-reactivity of the apoptotic protein bax and decreased the area of immune-reactivity of the anti-apoptotic protein bcl2 together with augmentation of the hepatic caspase 3 gene expression. The role of selenium in ameliorating the hepatotoxicity, oxidative stress injury, and apoptosis induced by ZnO-NPs, along with its role in modulating the JNK/p38MAPK and the STAT-3 signalling and improving the histopathological hepatic changes, offers selenium as a promising adjunctive therapy in individuals subjected to high concentrations of ZnO NPs especially in cases of extensive occupational, medicinal and industrial exposure.

Guavinoside B from Psidium guajava alleviates acetaminophen-induced liver injury via regulating the Nrf2 and JNK signaling pathways.

Benzophenone glycosides are a major type of polyphenols present in guava. To date, there is still poor understanding of the relationship between benzophenone glycosides and the hepatoprotective effects attributed to this edible fruit. Herein, the protective effects of guavinoside B (GUB), a main benzophenone glycoside present in guava fruit, against acetaminophen (APAP)-induced liver injury were investigated in vitro and in vivo. Fluorescence measurement demonstrated that GUB (at a concentration of 30 µM) significantly reduced the intracellular ROS levels in APAP-treated HepG2 cells. In addition, GUB (100 mg kg-1 d-1) pretreatment markedly alleviated APAP-induced hepatocyte infiltration and necrosis in C57BL/6 mice, and improved serum and hepatic biochemical parameters, such as ALT, AST, SOD, GSH, ROS, MDA, and TNF-α levels. RT-PCR and western blot experiments revealed that GUB up-regulated Nrf2, GCLC and NQO1, while reducing p-JNK gene expression in the liver. The fermentation experiment further revealed that the displayed beneficial effects of GUB in vivo might be related to the gut microbial metabolite gallic acid. These promising data suggested that GUB showed potent hepatoprotective effects through regulating the Nrf2 and JNK signaling pathways. Further investigation of the absorption and metabolism of benzophenones would be warranted to promote the utilization of these phenolics as functional food ingredients against oxidative stress-induced chronic diseases.

Type 2 diabetes risk gene Dusp8 regulates hypothalamic Jnk signaling and insulin sensitivity.

Recent genome-wide association studies (GWAS) identified DUSP8, encoding a dual-specificity phosphatase targeting mitogen-activated protein kinases, as a type 2 diabetes (T2D) risk gene. Here, we reveal that Dusp8 is a gatekeeper in the hypothalamic control of glucose homeostasis in mice and humans. Male, but not female, Dusp8 loss-of-function mice, either with global or corticotropin-releasing hormone neuron-specific deletion, had impaired systemic glucose tolerance and insulin sensitivity when exposed to high-fat diet (HFD). Mechanistically, we found impaired hypothalamic-pituitary-adrenal axis feedback, blunted sympathetic responsiveness, and chronically elevated corticosterone levels driven by hypothalamic hyperactivation of Jnk signaling. Accordingly, global Jnk1 ablation, AAV-mediated Dusp8 overexpression in the mediobasal hypothalamus, or metyrapone-induced chemical adrenalectomy rescued the impaired glucose homeostasis of obese male Dusp8-KO mice, respectively. The sex-specific role of murine Dusp8 in governing hypothalamic Jnk signaling, insulin sensitivity, and systemic glucose tolerance was consistent with functional MRI data in human volunteers that revealed an association of the DUSP8 rs2334499 risk variant with hypothalamic insulin resistance in men. Further, expression of DUSP8 was increased in the infundibular nucleus of T2D humans. In summary, our findings suggest the GWAS-identified gene Dusp8 as a novel hypothalamic factor that plays a functional role in the etiology of T2D.

Effect of transcutaneous electrical acupuncture point stimulation on expression of p-JNK in the dorsal root ganglion in a rat model of myofascial pain syndrome.

BACKGROUND: Acupuncture has been used to treat myofascial pain syndrome (MPS) for 2000 years in China, but its mechanisms are still not entirely clear. In the present study, we explored the effects of transcutaneous electrical acupuncture point stimulation (TEAS) at an Ashi acupuncture point on expression of phosphorylated c-Jun N-terminal kinase (p-JNK) in the dorsal root ganglion (DRG) using a rat model of MPS. METHODS: 32 rats were divided into four groups: normal, MPS, MPS+TEAS and MPS+sham- TEAS. MPS was produced by a blunt strike to the left vastus medialis combined with eccentric exercise for 8 weeks. Rats in the MPS+TEAS group received TEAS (6-9 mA, 2 Hz, 30 min) treatment at the Ashi acupuncture point for 2 weeks; rats in the MPS+sham -TEAS group had the same electrodes applied but received no stimulation. Paw withdrawal thermal latency (PWTL) was studied at baseline and on days 3, 7, 11 and 15 after treatment. Haematoxylin and eosin staining was used to examine for morphological changes in the left vastus medialis muscles; expression of p-JNK in the L3-L5 DRG was determined by immunofluorescence staining and western blotting after treatment. RESULTS: Compared with the normal group, PWTL decreased significantly (P<0.01) and the expression of p-JNK in the DRG increased in the MPS and MPS-sham-TEAS groups (P<0.01); compared with the MPS group, PWTL was increased significantly (P<0.01) and expression of p-JNK in the DRG was decreased in the MPS+TEAS group. However, when compared with the normal group, PWTL did not recover to baseline and expression of p-JNK was still higher. CONCLUSION: TEAS treatment may produce an analgesic effect, probably by inhibiting the expression of p-JNK in the DRG of rats with MPS.

Anti-Cancer Effects of Sulfasalazine and Vitamin E Succinate in MDA-MB 231 Triple-Negative Breast Cancer Cells.

Aim: Sulfasalazine (SSZ) displayed anti-cancer activities. Vitamin E succinate (VES) could inhibit cell growth in various cancer cells. However, chemical therapies were often not useful for triple-negative breast cancer cells (TNBCs) treatment. Here, this study investigated the anti-cancer effects and the mechanisms on TNBCs under combination treatment with SSZ and VES. Methods: Cell viability was analyzed by using the MTT assay. The H2O2 levels were determined by using lucigenin-amplified chemiluminescence method. In addition, caspase and MAPs signals were studied by using western blotting. Results: Low-dose VES antagonized the SSZ-induced cytotoxicity effects while high-dose VES promoted the SSZ-induced cytotoxicity effects on TNBCs. In addition, SSZ alone treatment activated both caspase-3 and ERK signals, however, VES alone treatment only activated JNK signals. On the other hand, activation of caspase-3, JNK, and ERK were found in SSZ plus VES-treated cells. Conclusion: Combined SSZ and VES has synergistic or antagonistic cytotoxic effects depending on VES concentration. In addition, different cytotoxic signals are induced on SSZ-treated, VES-treated and SSZ plus VES-treated cells.

Celastrol mediates autophagy and apoptosis via the ROS/JNK and Akt/mTOR signaling pathways in glioma cells.

BACKGROUND: Celastrol, a triterpene compound derived from the traditional Chinese medicine Tripterygium wilfordii, has been reported to possess potential antitumor activity towards various malignancies. However, the effect of celastrol on glioma cells and the underlying molecular mechanisms remain elusive. METHODS: Glioma cells, including the U251, U87-MG and C6 cell lines and an animal model were used. The effects of celastrol on cells were evaluated by flow cytometry, confocal microscopy, reactive oxygen species production assay and immunoblotting after treatment of celastrol. Fisher's exact test, a one-way ANOVA and the Mann-Whitney U-test were used to compare differences between groups. All data were analyzed using SPSS version 21.0 software. RESULTS: Here, we found that exposure to celastrol induced G2/M phase arrest and apoptosis. Celastrol increased the formation of autophagosomes, accumulation of LC3B and the expression of p62 protein. Celastrol-treated glioma cells exhibited decreased cell viability after the use of autophagy inhibitors. Additionally, autophagy and apoptosis caused by celastrol in glioma cells inhibited each other. Furthermore, celastrol induced JNK activation and ROS production and inhibited the activities of Akt and mTOR kinases. JNK and ROS inhibitors significantly attenuated celastrol-trigged apoptosis and autophagy, while Akt and mTOR inhibitors had opposite effects. CONCLUSIONS: In conclusion, our study revealed that celastrol caused G2/M phase arrest and trigged apoptosis and autophagy by activating ROS/JNK signaling and blocking the Akt/mTOR signaling pathway.

Chemopreventive Potential of Apple Pulp Callus Against Colorectal Cancer Cell Proliferation and Tumorigenesis.

This study focused on the evaluation of the chemopreventive potential of tissue in vitro culture of the "Mela Rosa Marchigiana" apple (MRM callus) that allows the amplification of secondary metabolites. The MRM pulp and MRM callus chemopreventive potential was evaluated in terms of antiproliferative activity, inhibition of tumorigenesis in soft agar cultures, cell cycle and western blotting analyses in CaCo2 and LoVo colon cancer cell lines and in JB6 promotion-sensitive (JB6 P+) cells. MRM callus induced a strong concentration-dependent inhibition of colon cancer cell proliferation and suppressed 12-o-tetra-decanoyl-phorbol-13-acetate-induced tumorigenesis of JB6 P+ cells in soft agar cultures. MRM callus inhibited the phosphorylation of JNK, p38, and eIF2alpha. Our data indicate that the MRM callus exerts a good antiproliferative and antitumorigenic potential through the MAP kinase inhibition and could provide natural compounds with chemopreventive properties.

Anti-Inflammatory Activity of Populus deltoides Leaf Extract via Modulating NF-κB and p38/JNK Pathways.

Populus deltoides, known as eastern cottonwood, has been commonly used as a medicinal plant. The aim of the present study was to investigate the mechanism underlying the anti-inflammatory activity of P. deltoides leaf extract (PLE). PLE effectively inhibited the expression of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, but not that of cyclooxygenase-2 (COX-2) and prostaglandin E2. Proinflammatory tumor necrosis factor alpha (TNF-α) levels were also reduced by the extract. PLE inhibited the phosphorylation of nuclear factor-kappa B (NF-κB) and inhibitor of Kappa Bα (IκBα), and blunted LPS-triggered enhanced nuclear translocation of NF-κB p65. In mitogen-activated protein kinase (MAPK) signaling, PLE effectively decreased the phosphorylation of p38 and c-Jun N-terminal protein kinase (JNK), but not of extracellular signal-regulated kinase 1/2 (ERK1/2). Taken together, these results suggest that anti-inflammatory activity of P. deltoides leaf extract might be driven by iNOS and NO inhibition mediated by modulation of the NF-κB and p38/JNK signaling pathways.

Long-term electroacupuncture stimulation prevents osteoporosis in ovariectomised osteopaenic rats through multiple signalling pathways.

BACKGROUND: The pathogenic mechanisms of postmenopausal osteoporosis (PMOP) development are complex and are related to multiple cellular signalling transduction pathways. The aim of this study was to compare the effects of electroacupuncture (EA) at GV4/GV6 versus BL20/BL23 on the bones in ovariectomised (OVX) rats to explore the pathways that mediate the effects of EA on bone. METHODS: Forty female Sprague-Dawley rats were allocated to one of four groups (n=10 rats each) that received sham surgery (Sham group), OVX surgery only (OVX group), OVX surgery plus EA at GV4/GV6 (GV group) and OVX surgery plus EA at BL20/BL23 (BL group). Bone turnover markers osteocalcin (OC) and tartrate-resistant acid phosphatase 5b (TRACP 5b) were measured in serum, and bone mineral density (BMD) of the lumbar vertebrae and histomorphology of the femur were evaluated. Moreover, the expression of osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) was detected by ELISA. The expression of lipoprotein receptor-related protein (LRP) 5, ß-catenin, runt-related transcription factor (Runx) 2 involving Wnt/ß-catenin signalling and p38, c-Jun N-terminal kinase (JNK) and extracellular regulated protein kinases 1/2 involving mitogen-activated protein kinase signalling were determined by Western blotting. RESULTS: The two EA-treated groups demonstrated increased levels of OC and the BMD of lumbar vertebrae, decreased levels of TRACP 5b and improved bone microstructure in the femur, compared with the untreated OVX group (P<0.05). Histomorphology analysis showed that EA treatment significantly increased the values of the trabeculae (µm), trabecular area (%) and trabecular bone number (per mm) and reduced trabecular separation (mm), compared with the OVX group. In addition, the ratio of OPG to RANKL and LRP5, ß-catenin and Runx2 expression were significantly upregulated, while the expression of phosphorylated (p)-p38 and p-JNK were downregulated in EA-treated groups compared with the OVX group. CONCLUSION: EA attenuates PMOP and it appears that the mechanism involves the regulation of multiple targets and pathways.

Anti-fibrotic activity of polyphenol-enriched sugarcane extract in rats via inhibition of p38 and JNK phosphorylation.

Sugarcane (Saccharum officinarum L.), which is one of the most important sources of sugar, is also rich in polyphenolic compounds. In this study, polyphenols from sugarcane were extracted, and the dominant component was characterized quantitatively via HPLC to be (-)-epicatechin. Fibrosis occurs in many organs and is associated with severe tissue damage. Liver fibrosis is the excessive accumulation of extracellular matrix proteins and advanced liver fibrosis, resulting in cirrhosis, liver failure and portal hypertension. Thus, the prevention and treatment of liver fibrosis is urgent. Therefore, we further investigated the protective effect of sugarcane polyphenol extract (SPE) on carbon tetrachloride-induced liver fibrosis in rats and observed that SPE (20 or 50 mg kg-1) improved the serum GOT (glutamic oxaloacetic transferase) and GPT (glutamic pyruvate transaminase) levels and decreased the expression of α-smooth muscle actin (α-SMA) in liver tissues. The mechanistic study showed that in transforming growth factor ß1(TGF-ß1)-induced hepatic stellate cells (HSCs), SPE attenuated the phosphorylation of p38 and JNK1/2 and down-regulated the expression of α-SMA. Collectively, SPE mitigated carbon tetrachloride-induced liver fibrosis in rats and its mechanism may be related to the p38 and JNK signalling pathways.

Coumestrol induces mitochondrial dysfunction by stimulating ROS production and calcium ion influx into mitochondria in human placental choriocarcinoma cells.

STUDY QUESTION: Does coumestrol inhibit proliferation of human placental choriocarcinoma cells? SUMMARY ANSWER: Coumestrol promotes cell death in the choriocarcinoma cells by regulating ERK1/2 MAPK and JNK MAPK signaling pathways and through disruption of Ca2+ and ROS homeostasis. WHAT IS KNOWN ALREADY: A number of patients who suffer from choriocarcinomas fail to survive due to delayed diagnosis or a recurrent tumor and resistance to traditional chemotherapy using platinum-based agents and methotrexate. To overcome these limitations, it is important to discover novel compounds which have no adverse effects yet can inhibit the expression of a target molecule to develop, as a novel therapeutic for prevention and/or treatment of choriocarcinomas. STUDY DESIGN, SIZE, DURATION: Effects of coumestrol on human placental choriocarcinoma cell lines, JAR and JEG3, were assessed in diverse assays in a dose- and time-dependent manner. PARTICIPCANTS/MATERIALS, SETTING, METHODS: Effects of coumestrol on cell proliferation, apoptosis (annexin V expression, propidium iodide staining, TUNEL and invasion assays), mitochondria-mediated apoptosis, production of reactive oxygen species (ROS), lipid peroxidation, glutathione levels and endoplasmic reticulum (ER) stress proteins in JAR and JEG3 cells were determined. Signal transduction pathways in JAR and JEG3 cells in response to coumestrol were determined by western blot analyses. MAIN RESULTS AND THE ROLE OF CHANCE: Results of the present study indicated that coumestrol suppressed proliferation and increased apoptosis in JAR and JEG3 cells by inducing pro-apoptotic proteins, Bax and Bak. In addition, coumestrol increased ROS production, as well as lipid peroxidation and glutathione levels in JAR and JEG3 cells. Moreover, coumestrol-induced depolarization of mitochondrial membrane potential (MMP) and increased cytosolic and mitochondrial Ca2+ levels in JAR and JEG3 cells. Consistent with those results, treatment of JAR and JEG3 cells with a Ca2+ chelator and an inhibitor of IP3 receptor decreased coumestrol-induced depolarization of MMP and increased proliferation in JAR and JEG3 cells. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: A lack of in vivo animal studies is a major limitation of this research. The effectiveness of coumestrol to induce apoptosis of human placental choriocarcinoma cells requires further investigation. WIDER IMPLICATIONS OF THE FINDINGS: Our results indicate that coumestrol induces apoptotic effects on placental choriocarcinoma cells by regulating cell signaling and mitochondrial-mediated functions, with a potential to impair progression of the cancer. STUDY FUNDING/COMPETING INTEREST(S): This research was supported by grants from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (No. HI15C0810 awarded to G.S. and HI17C0929 awarded to W.L.).

Pseudolaric acid B inhibits neuroglioma cell proliferation through DNA damage response.

Human neuroglioma is one of the most common malignant intracranial tumors in neurosurgery, and accounts for more than 50% of all brain cancer cases. Thus, a clinically effective drug with which to treat neuroglioma is urgently required. Pseudolaric acid B (PAB), a diterpene acid isolated from the root and trunk bark of Pseudolarix kaempferi Gordon (Pinaceae), was found to inhibit cell growth in a variety of cancer cell lines, but to date the effect of PAB on neuroglioma remains unclear. MTT analysis confirmed that PAB inhibited neuroglioma A172 cell growth in a time- and dose-dependent manner. In addition, PAB influenced the aggregation of tubulin in A172 cells. Meanwhile following PAB treatment, a higher percentage of cells accumulated in the G2/M phase from 12 to 48 h, while at 36 h, cell cycle slippage into the G0/G1 phase, and at 48 h, slippage into the S phase was observed using flow cytometric analysis. Corresponding protein expression was consistent with the cell cycle alteration as detected by western blotting, and it was speculated that cell cycle slippage was related to reduced effectiveness of PAB which warrants further investigation. Meanwhile PAB induced cell death by regulating p38, ERK and JNK expression and activating the DNA damage response. Therefore, PAB plays an antitumor role in A172 cells, and may be a candidate drug for neuroglioma therapy.

The expression of ERK and JNK in patients with an endemic osteochondropathy, Kashin-Beck disease.

Kashin-Beck disease (KBD) is a chronic, endemic osteochondropathy. Its etiopathogenesis is still obscure until now. Epidemiological observation has shown that low selenium play a crucial role in the pathogenesis of KBD. Extracellular signal-regulated kinases (ERKs) and C-Jun N-terminal kinase (JNK), members of the mitogen-activated protein kinase (MAPK) superfamily, play an important role in cell proliferation and differentiation. Nuclear factor-ĸB (NF-ĸB), an important signaling mediator for inflammatory and immune responses, is involved in the regulation of osteoclastogenesis. In the present study, we investigated the expression of ERK and JNK signal molecular, as well as nuclear factor-ĸB in the pathogenesis of Kashin-Beck disease, evaluated the effect of selenium on ERK signal pathway. The expression levels of ERK and JNK signal pathway, as well as nuclear factor-ĸB were investigated for 218 patients and 209 controls by immunoblot analysis in whole blood. Evaluated the effect of selenium on ERK signal pathway by Na2SeO3 treatment. The protein levels of pRaf-1, pMek1/2 and pErk1/2 decreased significantly in KBD patients, p-JNK and NF-ĸB increased in KBD patients. Furthermore, Na2SeO3 treatment improved the reduction of proteins in ERK signal pathway. These findings indicated that ERK and JNK signaling pathways, as well as the expression level of NF-κB signaling molecular are important contributor to the pathogenesis of KBD. Selenium stimulates the phosphorylation of the ERK signaling pathway.

Honokiol suppresses formyl peptide-induced human neutrophil activation by blocking formyl peptide receptor 1.

Formyl peptide receptor 1 (FPR1) mediates bacterial and mitochondrial N-formyl peptides-induced neutrophil activation. Therefore, FPR1 is an important therapeutic target for drugs to treat septic or sterile inflammatory diseases. Honokiol, a major bioactive compound of Magnoliaceae plants, possesses several anti-inflammatory activities. Here, we show that honokiol exhibits an inhibitory effect on FPR1 binding in human neutrophils. Honokiol inhibited superoxide anion generation, reactive oxygen species formation, and elastase release in bacterial or mitochondrial N-formyl peptides (FPR1 agonists)-activated human neutrophils. Adhesion of FPR1-induced human neutrophils to cerebral endothelial cells was also reduced by honokiol. The receptor-binding results revealed that honokiol repressed FPR1-specific ligand N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys-fluorescein binding to FPR1 in human neutrophils, neutrophil-like THP-1 cells, and hFPR1-transfected HEK293 cells. However, honokiol did not inhibit FPR2-specific ligand binding to FPR2 in human neutrophils. Furthermore, honokiol inhibited FPR1 agonist-induced calcium mobilization as well as phosphorylation of p38 MAPK, ERK, and JNK in human neutrophils. In conclusion, our data demonstrate that honokiol may have therapeutic potential for treating FPR1-mediated inflammatory diseases.

Sesamin prevents apoptosis and inflammation after experimental myocardial infarction by JNK and NF-κB pathways.

Myocardial infarction is a devastating event, especially when reperfusion is not performed. The inflammatory response has been associated with the pathogenesis of left ventricular remodeling after myocardial infarction. This study focused on the anti-apoptotic and anti-inflammatory effects of sesamin on ligation of the left anterior descending artery in an experimental mouse model and the potential mechanism underlying the activation of JNK and NF-κB pathways. Mice with MI induced by surgical left anterior descending coronary artery ligation were treated with sesamin by gavage for 1 week. Results showed that after treatment with sesamin, MI-induced cardiac damage was alleviated significantly, indicated by the histopathological examination. The myocardial apoptosis in the border zone was dramatically reduced by sesamin, resulting from the altered expression of apoptosis factors. Moreover, treatment with sesamin also mitigated the inflammatory response, decreased expression of cytokines and the inactivation of NF-κB (nuclear factor κB) signaling. Sesamin decreased the levels of p-JNK protein, which in turn inactivated pro-apoptotic signaling events by restoring the balance between mitochondrial pro-apoptotic Bcl-2 and Bax proteins. Thus, our study suggests that sesamin could alleviate MI-induced cardiac dysfunction through decrease of myocardial apoptosis and inflammatory response.

The preventive effects of taurine on neural tube defects through the Wnt/PCP-Jnk-dependent pathway.

The aim of this study was to clarify the protective role of taurine in neuronal apoptosis and the role of the Wnt/PCP-Jnk pathway in mediating the preventive effects of taurine on neural tube defects (NTDs). HT-22 cells (a hippocampal neuron cell line) were divided into a control group, a glutamate-induced apoptosis group, and glutamate (4.0 mmol/L) plus low-dose taurine (L; 0.5 mmol/L) and high-dose taurine (H; 2.0 mmol/L) groups. The MTT assay was used to monitor cell proliferation and cell survival. Immunofluorescence and Western blot analyses were used to determine caspase 9 expression. Retinoic acid (RA) induced embryonic NTDs in Kunming mice, thus establishing an NTD model. Pregnant mice were divided into a control group, an RA (30 mg/kg body weight) group, and an RA (30 mg/kg body weight) plus taurine (free drinking of 2 g/L solution) group. Immunohistochemistry and Western blot analyses were used to detect the expression of Dvl, RhoA and phosphorylated (p)-Jnk/Jnk in the embryonic neural tubes. In HT-22 cells, the apoptosis rate was significantly higher and caspase 9 activation was also significantly increased in the glutamate-induced apoptosis group compared to the L and H taurine groups. In the NTD model, the expression levels of Dvl, RhoA, and p-Jnk were significantly higher in the RA group than in the control group, whereas they were significantly reduced in the RA + taurine group. This study suggests that taurine has positive effects on neuronal protection and NTD prevention. Moreover, the Wnt/PCP-Jnk-dependent pathway plays an important role in taurine-mediated prevention of NTDs.