Extracellular Regulated Protein Kinases Research Articles

Upregulating miR-130a-5p relieves astrocyte over activation-induced neuropathic pain through targeting C-X-C motif chemokine receptor 12/C-X-C motif chemokine receptor 4 axis.

This study intends to explore the role and specific mechanism of miR-130a-5p in neuropathic pain through regulating the C-X-C motif chemokine receptor 12 (CXCL12)-C-X-C motif chemokine receptor 4 (CXCR4) pathway. First, mouse neuropathic pain model was constructed by spinal nerve ligation. MiR-130a-5p mimics were used to upregulate miR-130a-5p in vivo. The behaviour and pain scores of the spinal cord injury (SCI) mice were assessed. In addition, astrocytic activation as well as inflammatory response in the spinal lesions was determined. The results manifested miR-130a-5p was notably downregulated in neuropathic pain model and reached the lowest point at 3 days after injury. Besides, tail vein injection of miR-130a-5p mimics inhibited the activation and inflammatory response of astrocytes, thus alleviating chronic constriction injury-induced neuropathic pain. Moreover, miR-130a-5p inactivated CXCR4 and its downstream Rac1, nuclear factor-κB (NF-κB) and extracellular regulated protein kinases signalling pathways by attenuating CXCL12. MiR-130a-5p inactivated astrocytes by targeting CXCL12/CXCR4, thus alleviating SCI-induced neuropathic pain.

EDTA Promotes the Mineralization of Dental Pulp In Vitro and In Vivo

IntroductionDentin regeneration is one of the main goals of vital pulp treatment in which the biological properties of dental pulp cells (DPCs) need to be considered. In our previous study, we showed that EDTA could enhance the stromal cell–derived factor 1 alpha–induced migration of DPCs. The purpose of this study was to explore the effects of EDTA on the mineralization of dental pulp in vitro and in vivo. MethodsDPCs were obtained from human premolars or third molars. Alkaline phosphatase assays and alizarin red S staining were used to examine the degree of differentiation and mineralized nodule formation of DPCs. Real-time polymerase chain reaction and Western blot analysis were performed to detect the messenger RNA and protein expressions of mineralization-related markers in DPCs. Extracellular-regulated protein kinase and Smad inhibitors were used to study the roles of these 2 signaling pathways in this process. In addition, pulp exposures were created on 18 premolars of 2 beagle dogs (>12 months) using a high-speed dental handpiece. The experimental group (n = 9) was treated with 12% EDTA for 5 minutes, and the control group (n = 9) was treated with sterile saline for the same duration. Mineral trioxide aggregate was used for direct pulp capping followed by glass ionomer cement sealing. Samples were collected 3 months later, and the regenerated dentin was assessed by micro–computed tomographic and histologic analyses. ResultsExposure to 12% EDTA promoted the activity of alkaline phosphatase, the formation of mineralized nodules, and the messenger RNA and protein expressions of mineralization-related markers in DPCs. Furthermore, the process of 12% EDTA enhancing the differentiation of DPCs was mediated by the extracellular-regulated protein kinase 1/2 signaling pathway and inhibited by the Smad2/3 signaling pathway. In vivo, compared with the control group, more regenerated dentin that had fewer tunnel defects was formed in the 12% EDTA-treated group. ConclusionsOur results showed that 12% EDTA could promote the mineralization of dental pulp in vitro and in vivo.

Gain-of-function hot spot mutant p53R248Q regulation of integrin/FAK/ERK signaling in esophageal squamous cell carcinoma

PurposeTP53, encoding the protein p53, is among the most frequently mutated genes in all cancers. A high frequency of 60 – 90% mutations is seen in esophageal squamous cell carcinoma (ESCC) patients. Certain p53 mutants show gain-of-function (GoF) oncogenic features unrelated to its wild type functions. MethodsThis study functionally characterized a panel of p53 mutants in individual ESCC cell lines and assayed for GoF oncogenic properties. ResultsThe ESCC cell line with endogenous p53R248Q expression showed suppressed tumor growth in an immunocompromised mouse model and suppressed colony growth in in vitro three-dimensional culture, when depleted of the endogenous p53 protein expression. This suppression is accompanied by suppressed cell cycle progression, along with reduced integrin expression and decreased focal adhesion kinase and extracellular-regulated protein kinase signaling and can be compensated by expression of a constitutively active mitogen-activated protein. P53R248Q enhances cell proliferation upon glutamine deprivation, as compared to other non-GoF mutants. ConclusionsIn summary, study of the functional contributions of endogenous p53 mutants identified a novel GoF mechanism through which a specific p53 mutant exerts oncogenic features and contributes to ESCC tumorigenesis.

Schisandrin B inhibits α-melanocyte-stimulating hormone-induced melanogenesis in B16F10 cells via downregulation of MAPK and CREB signaling pathways.

Schisandrin B (Sch B), a lignan compound in Schisandra, possesses antioxidant, anti-inflammatory, and antiobesity activities. The effect of Sch B on melanogenesis and molecular mechanisms are still unknown. Therefore, we aimed to investigate the antimelanogenic effects of Sch B on α-melanocyte-stimulating hormone-induced B16F10 cells and elucidate the underlying molecular mechanisms. We found that Sch B significantly suppressed melanin content and mushroom tyrosinase (TYR) activity. Sch B treatment decreased the expression of TYR, melanocyte-inducing transcription factor (MITF), tyrosinase-related protein (TRP) 1, and TRP2. Moreover, Sch B modulated the phosphorylation of p38, extracellular-regulated protein kinase, c-Jun N-terminal kinase, and cAMP-response element binding protein (CREB), implying that these pathways may be involved in suppressing melanogenesis. Furthermore, we found that Sch B decreased melanogenesis by downregulating MITF and melanogenic enzymes via MAPK and CREB pathways. Overall, these findings indicate that Sch B has the potential use in whitening.

PTPN6 promotes chemosensitivity of colorectal cancer cells via inhibiting the SP1/MAPK signalling pathway.

The abnormal expression of protein tyrosine phosphatase nonreceptor type 6 (PTPN6) has been proved to be associated with the progression of colorectal cancer. However, its role in chemosensitivity and related molecular mechanism have not been clarified. It has been reported that PTPN6 was down-regulated in colorectal cancer cells compared with the normal colorectal cells. To evaluate the effects of PTPN6 on the proliferation and survival of colorectal cancer cells, PTPN6 was overexpressed in colorectal cancer cells in the present study. We found that cell proliferation and viability were both decreased after overexpression of PTPN6. The IC50 of 5-Fu against colorectal cells was also declined in PTPN6 transfected cells. And further, we verified that PTPN6 could down-regulate the expression of P-gp and MRP-1. Moreover, SP1 was the target protein of PTPN6 predicated by ChIPBase software and confirmed through Co-immunoprecipitation assay and it was negatively regulated by PTPN6. To further verify the effect of SP1 on chemoresistance, SP1 was overexpressed. SP1 overexpression enhanced the drug-resistance to 5-Fu and abrogated the effects of PTPN6 upregulation on 5-Fu resistance. All the above changes were associated with the down-regulation of proteins related to MAPK signalling pathway, such as phosphorylation of extracellular regulated protein kinases (ERK) and p38. In summary, PTPN6 promoted chemosensitivity of colorectal cancer cells by targeting SP1 and inhibiting the activation of MAPK signalling pathway. SIGNIFICANCE OF THE STUDY: It has been demonstrated that the abnormal expression of PTPN6 was related to the progression of colorectal cancer. However, the chemosensitivity of PTPN6 and its molecular mechanisms were still unclear. Here, we identified that PTPN6 was down-regulated in colorectal cancer cells. Moreover, PTPN6 overexpression not only reduced cell proliferation and viability, but decreased the resistance of colorectal cells to 5-Fu. In our research, we found that the SP1 was the target protein of PTPN6 and it was negatively regulated by PTPN6. In addition, SP1 could increase the resistance of colorectal cells to 5-Fu. Molecular mechanism studies have shown that PTPN6 promoted the chemosensitivity of colorectal cancer cells by inhibiting the activation of MAPK signalling pathway.

Anti-Osteoarthritic Effects of Terminalia Chebula Fruit Extract (AyuFlex®) in Interleukin-1β-Induced Human Chondrocytes and in Rat Models of Monosodium Iodoacetate (MIA)-Induced Osteoarthritis

Osteoarthritis (OA) is a general joint illness caused by the destruction of joint cartilage, and is common in the population of old people. Its occurrence is related to inflammatory reactions and cartilage degradation. AyuFlex® is an aqueous extract of Terminalia chebula fruit, and T. chebula has been utilized extensively in several traditional oriental medications for the management of diverse diseases. Pre-clinical and clinical research has shown its antioxidant and anti-inflammatory effectiveness. Nevertheless, the mechanism underlying the anti-arthritic effects of AyuFlex® remains unclear. In the current research, we proposed the ameliorating effects of AyuFlex® with respect to the incidence of OA and described the latent signalization in interleukin (IL)-1β-treated chondrocytes and MIA-incurred OA in a rat model. In vitro, AyuFlex® decreased oxidative stress and induction of pro-inflammatory cytokines and mediators as well as matrix metalloproteinases (MMPs), while also increasing the levels of collagen synthesis-related proteins. Mechanistically, we identified that AyuFlex® disrupted nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) activation via the inhibition of NF-κB p65 and extracellular regulated protein kinase (ERK) phosphorylation. The ameliorating effects of AyuFlex® were also observed in vivo. AyuFlex® significantly inhibited the MIA-incurred increase in OA symptoms such as oxidative stress, cartilage damage, and changes in cytokines and MMPs revelation in arthrodial cartilage. Therefore, our results suggest that AyuFlex® attenuates OA progression in vivo, indicating that AyuFlex® can be suggested as an excellent therapeutic remedy for the care of OA.

Discovery of Novel Dual Extracellular Regulated Protein Kinases (ERK) and Phosphoinositide 3-Kinase (PI3K) Inhibitors as a Promising Strategy for Cancer Therapy.

Concomitant inhibition of MAPK and PI3K signaling pathways has been recognized as a promising strategy for cancer therapy, which effectively overcomes the drug resistance of MAPK signaling pathway-related inhibitors. Herein, we report the scaffold-hopping generation of a series of 1H-pyrazolo[3,4-d]pyrimidine dual ERK/PI3K inhibitors. Compound 32d was the most promising candidate, with potent inhibitory activities against both ERK2 and PI3Kα which displays superior anti-proliferative profiles against HCT116 and HEC1B cancer cells. Meanwhile, compound 32d possessed acceptable pharmacokinetic profiles and showed more efficacious anti-tumor activity than GDDC-0980 and the corresponding drug combination (BVD-523 + GDDC-0980) in HCT-116 xenograft model, with a tumor growth inhibitory rate of 51% without causing observable toxic effects. All the results indicated that 32d was a highly effective anticancer compound and provided a promising basis for further optimization towards dual ERK/PI3K inhibitors.

Lactobacilli and bifidobacteria derived from infant intestines may activate macrophages and lead to different IL-10 secretion.

In this study, three strains of lactobacilli and bifidobacteria originally isolated from healthy infants, were tested for their abilities to activate RAW264.7 cells. Gene expression and cytokine production of interleukin-10 (IL-10) of RAW264.7 cells were evaluated. The activation of extracellular regulated protein kinases 1/2 (ERK1/2), p38, and nuclear factor-κB (NK-κB) were also assessed. These results suggest lactobacilli and bifidobacteria in infants may promote production of IL-10 in macrophages, conferring a protective effect in hosts suffering from inflammation. Dimerization of TLR2 and MyD88 and subsequent phosphorylation of the key downstream signaling molecules, such as MAPKs and NK-κB, may be one of the key underlying mechanisms of activation of macrophages by these microbes. Bifidobacteria and lactobacilli induced macrophages to secrete IL-10 in a different manner, which may relate to their abilities to activate key signaling pathways mediated by TLR2 and MyD88.

Hemocyte extracellular traps of Manila clam Ruditapes philippinarum: Production characteristics and antibacterial effects

Extracellular traps (ETs) have been found to be an important strategy of mammals to immobilize and kill invading microorganisms. In the present study, we observed the formation of ETs in the hemocytes of marine mollusks Ruditapes philippinarum in response to challenge from bacteria Vibrio anguillarum, and examined the potential factors and signaling pathways underling this process. We detected an increase of reactive oxygen species (ROS) and myeloperoxidase (MPO) production during ETosis, accompanied by significantly up-regulated expression of ROS-related and MPO genes. The suppression of ETs structures by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor (diphenyleneiodonium chloride, DPI) and MPO inhibitor (aminobenzoic acid hydrazide, ABAH) further confirmed the essential roles ROS and MPO played in ETosis. Furthermore, ET production could be inhibited by phosphotidylinsitol-3-kinase (PI3K) inhibitor (LY294002) and extracellular regulated protein kinase (ERK) inhibitor (U0126), suggesting the idea that both the PI3K and ERK pathways were suggested to function during ETosis. In addition, the ETosis process was accompanied by enhancement of glycolysis-related enzymatic activities, e.g., pyruvate kinase (PK) and hexokinase (HK), and over-expression of the glycolysis-related genes, e.g., PK, HK and glucose transport protein (GLUT), indicating high involvement of glycolysis in the ETosis process. Furthermore, our scanning electron microscopy (SEM) observation and antibacterial activities test successfully showed the patterns how clam ETs entrapped and killed the invading V. anguillarum. Taken together, our results revealed that ETosis with bactericidal effect increased ROS, MPO and glycolysis level and carried out in a ROS-, MPO-, PI3K-ERK-dependent manner.

Quercetin exerts antidepressant and cardioprotective effects in estrogen receptor α-deficient female mice via BDNF-AKT/ERK1/2 signaling

Brain-derived neurotrophic factor (BDNF) is the potential link between depression and cardiovascular disease and estrogen receptor α (ERα), an estrogen-mediated major regulator, plays an important role in protecting against depression and cardiovascular disease. However, the relationship between BDNF and ERα remains obscure. Herein, quercetin (QUE), a kind of plant flavonoids and existed in many vegetables and fruits, was found to simultaneously reverse ERα−/−-induced depression-like and cardiac dysfunction by reducing immobility time in the tail suspension test (TST) and forced swimming test (FST), and decreasing systolic blood pressure and activating the apoptosis-related proteins, BDNF, tropomyosin-related kinase B (TrkB), protein kinase B (AKT), and extracellular regulatory protein kinase (ERK1/2) in the hippocampal and cardiac tissues of female mice. These findings suggested that ERα might be involved in the regulation of BDNF activity, thereby regulating depression-like and cardiovascular responses in female mice, and QUE exerted significant antidepressant and cardioprotective effects, at least in part, through BDNF-TrkB-AKT/ERK1/2 to effectively inhibit ERα−/−-induced hippocampal and cardiac dysfunction.

Neuroprotective potential of isothiocyanates in an in vitro model of neuroinflammation

Isothiocyanates (ITCs), present as glucosinolate precursors in cruciferous vegetables, have shown anti-inflammatory, antioxidant and anticarcinogenic activities. Here, we compared the effects of three different ITCs on ROS production and on the expression of matrix metalloproteinase (MMP)-2 and -9, which represent important pathogenetic factors of various neurological diseases. Primary cultures of rat astrocytes were activated by LPS and simultaneously treated with different doses of Allyl isothiocyanate (AITC), 2-Phenethyl isothiocyanate (PEITC) and 2-Sulforaphane (SFN). Results showed that SFN and PEITC were able to counteract ROS production induced by H2O2. The zymographic analysis of cell culture supernatants evidenced that PEITC and SFN were the most effective inhibitors of MMP-9, whereas, only SFN significantly inhibited MMP-2 activity. PCR analysis showed that all the ITCs used significantly inhibited both MMP-2 and MMP-9 expression. The investigation on the mitogen-activated protein kinase (MAPK) signaling pathway demonstrated that ITCs modulate MMP transcription by inhibition of extracellular-regulated protein kinase (ERK) activity. Results of this study suggest that ITCs could be promising nutraceutical agents for the prevention and complementary treatment of neurological diseases associated with MMP involvement.

N-type Cav channel inhibition by spider venom peptide of Argiope bruennichi

The spider venom is composed of various bioactive peptides and has well-known physiological characteristics, such as cytolytic and neurotoxic activities. However, there have been few studies on neurotoxic peptides derived from domestic indigenous spiders in Korea. The study aimed to characterize and identify the venom peptide through genomic analysis from the domestic indigenous spider, Argiope bruennichi. Toxin-like peptides were selected using homology analysis against well-known toxin peptides along with the secondary structural characterization analysis by cysteine pattern and disulfide bonds. Modulation of voltage-gated calcium (Cav) channel was measured by Ca2+ influx using fluorescence dye. We found that a novel peptide Aranetoxin-Ab1a significantly reduced intracellular Ca2+ levels in human neuroblastoma cell line SH-SY5Y via the inactivation of N-type Cav channels. Decreased intracellular Ca2+ influx by the treatment of the peptide inactivated the extracellular-regulated protein kinase 1/2 and cAMP-response factor binding protein pathway. Our results provide beneficial information for the potential development of drugs utilizing novel peptide derived from spider venom, showing the inhibition of N-type Cav by the peptide.

Norcantharidin induces G2/M arrest and apoptosis via activation of ERK and JNK, but not p38 signaling in human renal cell carcinoma ACHN cells.

Renal cell carcinoma (RCC) is generally acknowledged as the most resistant primary malignancy unresponsive to conventional radiotherapy and chemotherapy treatments. Norcantharidin (NCTD), a therapeutic compound derived from medicinal plants, has been shown to trigger apoptosis, as well as antimetastatic and antioxidant activities in several tumor cells. However, NCTD's mechanism of antitumor activity in the RCC cell line remains unclear. In this study, we report that NCTD led to a time- and dose-dependent inhibition of cell proliferation. It had also markedly induced apoptosis and G2/M phase cell cycle arrest in a dose-dependent manner by decreasing the expressions of pro-caspase-3, pro-caspase-9, cyclin B1, and pCDC25C while increasing active caspase-3, cleaved-PARP, P21, and pCDC2 levels. Interestingly, NCTD treatment provoked the phosphorylation of extracellular-regulated protein kinase (ERK) and c-Jun-N-terminal kinase (JNK), but not of p38 MAPK. Moreover, SCH772984 and SP600125, ERK and JNK inhibitors, respectively, could partially abolish NCTD-induced apoptosis and G2/M phase cell cycle arrest. Collectively, these findings suggest that NCTD might activate JNK and ERK signaling pathways, consequently inducing apoptosis and G2/M arrest through the modulation of related proteins. This study provided evidence that NCTD is a promising therapeutic drug for the treatment of RCC.

MMP-1 promotes osteogenic differentiation of human bone marrow mesenchymal stem cells via the JNK and ERK pathway.

Enhancing the functions of mesenchymal stem cells (MSCs) is considered a potential approach for promoting tissue regeneration. In this study, we investigated the effects of Matrix Metalloproteinase-1 (MMP-1) on bone marrow mesenchymal stem cells (BMSCs) and its mechanism. Our results showed that knockdown of MMP-1 impeded scratch closure, attenuated proliferation, inhibited ALP activity, ALP denser staining and mineralization in vitro, and decreased expression of RUNX2, OSX, OPN and OCN in BMSCs, while 20 ng/mL recombinant human MMP-1 protein (rhMMP-1) significantly accelerated scratch closure, enhanced proliferation, ALP activity, ALP denser staining and mineralization in vitro, and increased expression of RUNX2, OSX, OPN and OCN. In addition, knockdown of MMP-1 inhibited the expression of phosphorylated c-Jun N-terminal kinase (p-JNK) and phosphorylated extracellular regulated protein kinases (p-ERK), while 20 ng/mL rhMMP-1 increased the expression of p-JNK and p-ERK in BMSCs. Furthermore, inhibition of c-Jun N-terminal kinase (JNK) and extracellular regulated protein kinases (ERK) by their inhibitor SP600125 and PD98059 dramatically blocked MMP-1-enhanced ALP activity and mineralization in BMSCs. Our results revealed that MMP-1 could accelerate the osteogenic differentiation potentials of BMSCs via the JNK and ERK pathway, providing the mechanism underlying MSC biology and identifying a potential target for improving bone tissue regeneration.

Mangiferin Inhibits Apoptosis and Autophagy Induced by Staphylococcus aureus in RAW264.7 Cells.

PurposeStaphylococcus aureus (S. aureus) is an important bacterial pathogen, which creates infective inflammation to human being and animals. Mangiferin (MG) is one of the natural flavonoids with anti-inflammatory, anti-bacterial, and anti-oxidative properties. However, the anti-apoptosis and anti-autophagy of MG are unknown. Hence, this study was aimed to research the inhibition of MG on S. aureus-induced apoptosis and autophagy in RAW264.7 cells.MethodsThe RAW264.7 cells were pretreated with MG, or pretreated with SP600125 or anisomycin synchronously, and then infected with S. aureus (MOI=100:1). The viability and proliferation status of RAW264.7 cells were detected by MTT and EdU assay. The relative expression of TNF-α, IL-6 and IL-10 protein was tested with ELISA. The levels of Bax, Bcl-2, caspase-3, c-Jun N-terminal kinase (JNK), extracellular-regulated protein kinase (ERK), p38, LC3, Beclin-1, p62, phosphorylated JNK, phosphorylated p38 and phosphorylated ERK in cells were detected by Western blotting. The apoptosis rate of RAW264.7 cells was analyzed by flow cytometric assay.ResultsThe study showed that MG significantly attenuated RAW264.7 cells apoptosis and autophagy caused by S. aureus. MG alleviated S. aureus-induced apoptosis by down-regulating the protein level of active caspase-3 and Bax and up-regulating the level of Bcl-2. MG also inhibited S. aureus-induced autophagy via decreasing the protein level of LC3-II/LC3-I and Beclin-1 or increasing the protein expression of p62. This protective role was dependent on the up-regulation of JNK signal pathway, which was confirmed by using JNK agonist and inhibitor.ConclusionOur results demonstrated that MG might protect RAW264.7 cells from S. aureus-induced apoptosis and autophagy via inhibiting JNK/Bax-dependent signal pathway. Therefore, MG may be a potential agent against pathological cell damage induced by S. aureus infection.

Lactobacillus plantarum inhibited the inflammatory response induced by enterotoxigenic Escherichia coli K88 via modulating MAPK and NF-κB signalling in intestinal porcine epithelial cells.

To investigate the effects of Lactobacillus plantarum on inflammatory responses induced by ETEC K88 and explore the underlying molecular mechanisms. Intestinal porcine cells (IPEC-1) were incubated with 0 or 1×108 CFU per well L. plantarum for 4h, and then these cells were challenged with 0 or 1×108 CFU per well ETEC K88 for 2h. The results showed that pre-treatment of IPEC-1 cells with L. plantarum prevented the increases in the transcript abundance of interleukin-1α (IL-1α), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumour necrosis factor-α (TNF-α) (P<0·05) caused by ETEC K88. Additionally, L. plantarum inhibited the reduction in peroxisome proliferator-activated receptor-γ (PPAR-γ) expression caused by ETEC K88 (P<0·05). Moreover, L. plantarum pre-treatment downregulated the phosphorylation levels of c-Jun N-terminal kinase (JNK), extracellular regulated protein kinases 1 and 2 (ERK1/2) and p38 and the nuclear concentration of nuclear factor kappa B p65 (NF-κB p65) (P<0·05) compared with ETEC K88 group. Silencing experiment further supported that the protective effect of L. plantarum P might mediated by suppression of ETEC-provoked activation of MAPK and NF-κB signalling pathways. Lactobacillus plantarum inhibited the inflammatory response induced by ETEC K88 in IPEC-1 cells via modulating MAPK and NF-κB signalling. This study elucidated the underlying mechanism in which probiotics protect against intestinal inflammation caused by ETEC K88.

Effect of shikonin on function of rheumatoid arthritis fibroblast like synoviocytes

To observe the effect of shikonin on the proliferation, migration, adhesion and invasion of rheumatoid arthritis(RA) fibroblast like synoviocytes induced by tumor necrosis factor-α(TNF-α), and to explore its mechanism of action from aspects of protein kinase B(Akt) and mitogen activated protein kinase(MAPK) signaling pathways. TNF-α(20 ng·mL~(-1)) was used in this experiment to induce human RA fibroblast like synovial cell line(MH7 A). After addition of different concentrations of shikonin(0.025, 0.05, 0.1 pmol·L~(-1)), the proliferation, migration, adhesion and invasion ability of MH7 A cells were detected by MTT test, scratch test, adhesion test, Transwell invasion test, respectively. Protein expression of Akt and MAPK signaling pathway molecules in MH7 A cells was detected by Western blot. The results showed that as compared with the control group, TNF-α could significantly induce the proliferation, migration, adhesion and invasion of MH7 A cells, and increase the phosphorylation level of Akt, JNK, p38 and extracellular regulatory protein kinase(ERK). As compared with the TNF-α group, shikonin had no significant effect on TNF-α-induced proliferation of MH7 A cells after 24 h treatment, and it could reduce the TNF-α-induced proliferation of MH7 A cells in a concentration dependent manner after 48 h treatment. Shikonin also significantly reduced the TNF-α-induced migration, adhesion, invasion and phosphorylation levels of Akt, JNK, p38, ERK in MH7 A cells within 24 h. These results suggested that shikonin could reduce the proliferation, migration, adhesion and invasion ability of MH7 A cells induced by TNF-α, and its mechanism may be related to the down-regulation of Akt and MAPK signaling pathway activation.

Time-restricted feeding improves the reproductive function of female mice via liver fibroblast growth factor 21.

BackgroundThere has been a significant increase, to epidemic levels, of obese and overweight women of reproductive age, causing impairments to reproductive health. Time‐restricted feeding (TRF) including isocaloric intake has shown to be preventive of obesity‐related disorders. However, its therapeutic ability to improve the reproductive function of female remains largely unknown.MethodsHere, we investigated the ability of TRF to improve the reproductive function in wild‐type and liver‐specific FGF21 knockout female mice. To study fertility, a continuous and a short‐term fertility test, gonadotropin releasing‐hormone (GnRH), and Kisspeptin test were performed. Immortalized GnRH neuron was used to examine the direct role of liver fibroblast growth factor 21 (FGF21) on GnRH secretion.ResultsWe found that TRF rescues female mice from bodyweight gain and glucose intolerance, as well as ovarian follicle loss and dysfunction of estrus cyclicity induced by high‐fat diet. Furthermore, the beneficial effects of the TRF regimen on the reproductive performance were also observed in mice fed both chow and high‐fat diet. However, those beneficial effects of TRF on metabolism and reproduction were absent in liver‐specific FGF21 knockout mice. In vitro, FGF21 directly acted on GnRH neurons to modulate GnRH secretion via extracellular regulated protein kinases (ERK1/2) pathway.ConclusionsOverall, time‐restricted feeding improves the reproductive function of female mice and liver FGF21 signaling plays a key role in GnRH neuron activity in female mice.

Effect of enhancer of zeste homolog 2 inhibitor GSK126 on the proliferation and apoptosis of tongue squamous cell carcinoma

This study aims to study the effect of the enhancer of zeste homolog 2 (EZH2) inhibitor GSK126 on the proliferation and apoptosis of human tongue squamous cell carcinoma cells in vitro and explore its related mechanisms in order to obtain insights into the clinical treatment of tongue squamous cell carcinoma. Different concentrations of GSK126 were applied to CAL-27 cells of tongue squamous cell carcinoma, and the effects of drugs on cell proliferation were detected through methyl thiazolyl tetrazolium (MTT) assay, colony formation assay, and 5-ethynyl-2'-deoxyuridine (EdU) fluorescence staining. Hoechst33342 fluorescence staining and the JC-1 method were used in observing apoptosis. The expression levels of extracellular regulated protein kinases (ERK), phospho-extracellular regulated protein kinases (p-ERK), Bax, Bcl-2, and Cleaved caspase-9 in Cal-27 cells were detected through Western blot. GSK126 inhibited CAL-27 cell proliferation and promoted apoptosis. GSK126 down-regulated the expression of p-ERK and Bcl-2 and increased the expression of Bax and Cleaved caspase-9 (P<0.05). GSK126 can inhibit the proliferation of CAL-27 cells in tongue squamous cell carcinoma and promote its apoptosis, and the related mechanism may be associated with the inhibition of the MEK/ERK signaling pathway and activation of the Bax/Bcl-2 pathway.

Effect of Zhongyi paste on inflammatory pain in mice by regulation of the extracellular regulated protein kinases 1/2-cyclooxygenase-2-prostaglandin E2 pathway.

BackgroundZhongyi paste is a traditional Chinese medicine herbal paste that is externally applied to reduce inflammation and relieve pain.MethodsAn acute foot swelling inflammation model in C57BL/6J mice was established by carrageenan-induced pathogenesis. Zhongyi paste raised the pain threshold and also reduced the degree of swelling in mice with carrageenan-induced foot swelling.ResultsAnalysis indicated that serum tumor necrosis factor-alpha, interleukin-1 beta, and prostaglandin E2 (PGE2) cytokine levels and PGE2 levels in the paw tissue of the mice were decreased by Zhongyi paste treatment. The quantitative polymerase chain reaction and western blot results showed that Zhongyi paste downregulated the mRNA and protein expression of extracellular signal-regulated kinase 1/2 (ERK1/2), and cyclooxygenase-2 (COX-2), and also downregulated the mRNA expression of PGE2. At the same time, the Zhongyi paste exerted a stronger effect as an external drug than that of indomethacin, which is an oral drug, and voltaren, which is an externally applied drug.ConclusionsOur results indicated that Zhongyi paste is a very effective drug to reduce inflammatory swelling of the foot, and its mechanism of action is related to regulation of the ERK1/2–COX-2–PGE2 pathway.