Animals ; Cell Nucleus ; enzymology ; Drosophila Proteins ; genetics ; metabolism ; Drosophila melanogaster ; Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Long-Term Potentiation ; physiology ; MAP Kinase Signaling System ; physiology ; Memory Consolidation ; physiology ; Neurons ; cytology ; enzymology

BACKGROUNDPreviously, we reported that dual-specificity phosphatase 1 (DUSP1) was differentially expressed in endometrioid adenocarcinoma (EEA). However, the role of DUSP1 in EEA progression and the relationship between DUSP1 and medroxyprogesterone (MPA) are still unclear.

METHODSThe expression of DUSP1 in EEA specimens was detected by immunohistochemical analysis. The effect of DUSP1 on cell proliferation was analyzed by Cell Counting Kit 8 and colony formation assay, and cell migration was analyzed by transwell assay. MPA-induced DUSP1 expression in EEA cells was measured by Western blot.

RESULTSDUSP1 expression was deficient in advanced International Federation of Gynecology and Obstetrics stage, high-grade and myometrial invasive EEA. In EEA cell lines (Hec1A, Hec1B, RL952, and Ishikawa), the DUSP1 expression was substantially higher in Ishikawa cells than in other cell lines (P < 0.05). Knockdown of DUSP1 promoted Ishikawa cells proliferation, migration, and activation of mitogen-activated protein kinases/extracellular signal-regulated kinase (MAPK/Erk) pathway. MPA-induced DUSP1 expression and inhibited MAPK/Erk pathway in Ishikawa cells.

CONCLUSIONSOur data suggest that DUSP1 deficiency promotes EEA progression via MAPK/Erk pathway, which may be reversed by MPA, suggesting that DUSP1 may serve as a potential therapeutic target for the treatment of EEA.

Carcinoma, Endometrioid ; metabolism ; Cell Culture Techniques ; Cell Proliferation ; genetics ; physiology ; Dual-Specificity Phosphatases ; genetics ; metabolism ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Female ; Humans ; Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVETo investigate the effect of extracellular signal-regulated kinase (ERK) signaling pathway on the endothelial differentiation of periodontal ligament stem cells (PDLSC).

METHODSHuman PDLSC was cultured in the medium with vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF) to induce endothelial differentiation. Endothelial inducing cells was incubated with U0126, a specific p-ERK1/2 inhibitor. PDLSC from one person were randomly divided into four groups: control group, endothelial induced group, endothelial induced+DMSO group and endothelial induced+U0126 group. The protein expression of the p-EKR1/2 was analyzed by Western blotting at 0, 1, 3, 6 and 12 hours during endonthelial induction. The mRNA expressions of CD31, VE-cadherin, and VEGF were detected by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) after a 7-day induction. The proportion of CD31(+) to VE-cadherin(+) cells was identified by flow cytometry, and the ability of capillary-like tubes formation was detected by Matrigel assay after a 14-day induction. The measurement data were statistically analyzed.

RESULTSPhosphorylated ERK1/2 protein level in PDLSC was increased to 1.24±0.12 and 1.03±0.24 at 1 h and 3 h respectively, during the endothelial induction (P<0.01). The mRNA expressions of CD31 and VEGF in induced+U0126 group were decreased to 0.09±0.18 and 0.49±0.17, which were both significantly different with those in induced group (P<0.05). The proportion of CD31(+) to VE-cadherin(+) cells of induced+U0126 group were decreased to 5.22±0.85 and 3.56±0.87, which were both significantly different with those in induced group (P<0.05). In Matrigel assay, the branching points, tube number and tube length were decreased to 7.0±2.7, 33.5±6.4, and (15 951.0±758.1) pixels, which were all significantly different with those in induced group (P<0.05).

CONCLUSIONSThe endothelial differentiation of PDLSC is positively regulated by ERK signaling pathway. Inhibition of ERK1/2 phosphorylation could suppress endothelial differentiation of PDLSC.

Antigens, CD ; genetics ; metabolism ; Butadienes ; pharmacology ; Cadherins ; genetics ; metabolism ; Cell Differentiation ; Endothelial Cells ; cytology ; physiology ; Enzyme Inhibitors ; pharmacology ; Extracellular Signal-Regulated MAP Kinases ; physiology ; Fibroblast Growth Factor 2 ; pharmacology ; Humans ; Mitogen-Activated Protein Kinase 3 ; antagonists & inhibitors ; metabolism ; Nitriles ; pharmacology ; Periodontal Ligament ; cytology ; metabolism ; Phosphorylation ; Platelet Endothelial Cell Adhesion Molecule-1 ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Random Allocation ; Signal Transduction ; Stem Cells ; cytology ; physiology ; Time Factors ; Vascular Endothelial Growth Factor A ; genetics ; metabolism ; pharmacology

OBJECTIVETo investigate the potential involvement of DMT1 (IRE) protein in the brain vascular system in vivo during Pb exposure.

METHODSThree groups of male Sprague-Dawley rats were exposed to Pb in drinking water, among which two groups were concurrently administered by oral gavage once every other day as the low and high Fe treatment group, respectively, for 6 weeks. At the same time, the group only supplied with high Fe was also set as a reference. The animals were decapitated, then brain capillary-rich fraction was isolate from cerebral cortex. Western blot method was used to identify protein expression, and RT-PCR to detect the change of the mRNA.

RESULTSPb exposure significantly increased Pb concentrations in cerebral cortex. Low Fe dose significantly reduced the cortex Pb levels, However, high Fe dose increased the cortex Pb levels. Interestingly, changes of DMT1 (IRE) protein in brain capillary-rich fraction were highly related to the Pb level, but those of DMT1 (IRE) mRNA were not significantly different. Moreover, the consistent changes in the levels of p-ERK1/2 or IRP1 with the changes in the levels of DMT1 (IRE).

CONCLUSIONThese results suggest that Pb is transported into the brain through DMT1 (IRE), and the ERK MAPK pathway is involved in DMT1 (IRE)-mediated transport regulation in brain vascular system in vivo.

Animals ; Blood-Brain Barrier ; drug effects ; metabolism ; Cation Transport Proteins ; drug effects ; genetics ; physiology ; Cerebral Cortex ; drug effects ; metabolism ; Dietary Supplements ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Gene Expression Regulation ; drug effects ; Iron ; administration & dosage ; metabolism ; Lead ; administration & dosage ; pharmacokinetics ; MAP Kinase Signaling System ; physiology ; Male ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the role of extracellular signal-regulated kinase (ERK) in apoptosis of human colon cancer (HCT116) cells.

METHODSAfter the HCT116 cells were pretreated with specific ERK inhibitor (U0126) or specific siRNA and exposed to 10 mmol/L sodium butyrate (NaBT) for 24 h, their apoptosis was detected by flow cytometry, levels of SphK2 and ERK protein were measured by Western blot, and translocation of SphK2 was assayed by immunofluorescence microscopy.

RESULTSThe U0126 and siRNAs specific for SphK2 blocked the export of SphK2 from nuclei to cytoplasm and increased the apoptosis of HCT116 cells following NaBT exposure. Over-expression of PKD decreased NaBT-induced apoptosis of HCT116 cells, which was reversed by U0126. Furthermore, transfection of HCT116 cells with constitutively activated PKD plasmids recovered the U0126-blocked export of SphK2.

CONCLUSIONERK regulates the export of SphK2 and apoptosis of HCT116 cells by modulating PKD. Modulation of these molecules may help increase the sensitivity of colon cancer cells to the physiologic anti-colon cancer agent, NaBT.

Apoptosis ; drug effects ; physiology ; Butyric Acid ; pharmacology ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; HCT116 Cells ; drug effects ; Humans ; Phosphotransferases (Alcohol Group Acceptor) ; genetics ; metabolism ; Protein Kinase C ; genetics ; metabolism ; RNA, Small Interfering ; Signal Transduction ; drug effects

The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) and phoshoinositide-3-kinase/protein kinase B (PI3K/Akt) signaling pathways play a major role in regulating cell growth, proliferation and apoptosis, via transmission of cell signals to cell nucleus. The genes, coding the MAPK/ERK and PI3K/Akt signaling cascade proteins, are significantly mutated in thyroid cancer. Genetic alternations contribute to aberrant activations and interaction of MAPK/ERK and PI3K/Akt signaling pathways in consequence of malignant follicular cell transformation and progression. This review focuses mainly on the role of genetic alterations in coding MAPK/ERK and PI3K/Akt signaling pathway proteins in generation, progression and diagnosis of thyroid cancer. Moreover, it additionally points out a therapeutic potential in restoring iodine avidity of thyroid cancer cells for radionuclide targeted treatment, by synergistically inhibiting activity of signaling pathways.
Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Humans ; MAP Kinase Signaling System ; genetics ; Mitogen-Activated Protein Kinases ; genetics ; metabolism ; Mutation ; Phosphatidylinositol 3-Kinases ; genetics ; metabolism ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Signal Transduction ; genetics ; physiology ; Thyroid Neoplasms ; genetics ; physiopathology ; therapy

OBJECTIVETo explore the signal transduction pathway mediated by thrombopoietin (TPO) in the inflammation model of microglia induced by lipopolysaccharide (LPS).

METHODSThe inflammation model of microglia BV2 cells was prepared by LPS of 0.5 and 1.0 μg/mL stimulation. The expression of TPO and ERK mRNA in BV2 cells was detected by real time quantitative PCR. Western blot was used to evaluate the expression of TPO and ERK protein in BV2 cells. TPO and IL-6 contents in the culture supernatant fluid were measured using ELISA.

RESULTSLPS stimulation increased significantly the mRNA and protein expression of TPO and ERK in BV2 cells, especially at the concentration of 1.0 μg/mL for 12 hrs stimulation. There was a significant positive correlation between the mRNA and protein expression of TPO and ERK.

CONCLUSIONSSignal transduction pathway of ERK1/2 participates in the activation of TPO in inflammatory injury of BV2 cells.

Animals ; Enzyme-Linked Immunosorbent Assay ; Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Inflammation ; etiology ; Mice ; Microglia ; pathology ; RNA, Messenger ; analysis ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; physiology ; Thrombopoietin ; analysis ; genetics ; physiology

OBJECTIVETo study the effect of chronic multiple stress on learning and memory, and the expression and activation of cerebral extracellular signal-regulated protein kinase (ERK) 1/2 of rats in vivo.

METHODSNinety male SD rats were divided randomly into control group and stress group. Rats in stress group were stressed everyday by one of the seven stressors including cold exposure, foot shock, white noise, restraint, tail hung up, sleep deprivation, and level shake, and then the ability of learning and memory was determined by Morris water maze test. Serum corticosterone (CORT) level was determined by radioimmunoassay kit. Western blot was performed to determine the expression and phosphorylation of ERK in hippocampus and prefrontal cortex of the brain.

RESULTSThe escape latencies of stressed rats were substantially longer than those of the controls in the water maze test (P < 0.01) except a transient recovery at the end of the third week after the stress. The stress also resulted in significantly higher serum CORT level and decreased P-ERK level in hippocampus and prefrontal cortex (PFC) (P < 0.01). Similarly, transient elevation of both CORT and P-ERK levels were observed at the end of the third week.

CONCLUSIONChronic multiple stress can lead to impaired learning and memory by decreasing the phosphorylation of ERK in the hippocampus and PFC. The partial recovery of learning and memory, CORT and P-ERK levels at the end of the third week may due to the adaptation of the rats to stressors.

Animals ; Cerebral Cortex ; enzymology ; physiopathology ; Corticosterone ; blood ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Hippocampus ; enzymology ; physiopathology ; Male ; Maze Learning ; physiology ; Memory Disorders ; enzymology ; etiology ; physiopathology ; Phosphorylation ; Rats ; Rats, Sprague-Dawley ; Stress, Physiological

OBJECTIVE: To investigate the role of focal adhesion kinase (FAK) in extracellular signal-regulated kinase (ERK) signaling pathway mediated invadsion of trophoblasts. METHODS: We established a human extravillous cytotrophoblasts in vitro invasion model. Different concentrations of herbimycin A(FAK inhibitor)and PD98059 (ERK inhibitor) were given to observe the influence on the growth of trophoblast cells, FAK, ERK phosphorylation, and trophoblast invasion abilities. RESULTS: The expression of phosphorylated FAK in the extravillous cytotrophoblasts (EVCT) was inhibited by herbimycin A in a concentration-dependent manner and expression of phosphorylated ERK1/2 was also partially reduced. PD98059 had no effect on the expression of phosphorylated FAK. Herbimycin A and PD98059 suppressed the in vitro invasion of EVCT to various degrees. CONCLUSION ERK signaling pathway may be the common pathway for many invasive signals,and play a key role in the regulation of trophoblast invasion.
Benzoquinones ; pharmacology ; Cell Division ; physiology ; Cell Movement ; physiology ; Extracellular Signal-Regulated MAP Kinases ; antagonists & inhibitors ; metabolism ; Flavonoids ; pharmacology ; Focal Adhesion Protein-Tyrosine Kinases ; antagonists & inhibitors ; metabolism ; Humans ; Lactams, Macrocyclic ; pharmacology ; Phosphorylation ; Rifabutin ; analogs & derivatives ; Signal Transduction ; physiology ; Trophoblasts ; cytology ; physiology

Cholesterol is one of major components of cell membrane and plays a role in vesicular trafficking and cellular signaling. We investigated the effects of cholesterol on matrix metalloproteinase-2 (MMP-2) activation in human dermal fibroblasts. We found that tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) expression and active form MMP-2 (64 kD) were dose-dependently increased by methyl-beta-cyclodextrin (MbetaCD), a cholesterol depletion agent. In contrast, cholesterol depletion-induced TIMP-2 expression and MMP-2 activation were suppressed by cholesterol repletion. Then we investigated the regulatory mechanism of TIMP-2 expression by cholesterol depletion. We found that the phosphorylation of JNK as well as ERK was significantly increased by cholesterol depletion. Moreover, cholesterol depletion-induced TIMP-2 expression and MMP-2 activation was significantly decreased by MEK inhibitor U0126, and JNK inhibitor SP600125, respectively. While a low dose of recombinant TIMP-2 (100 ng/ml) increased the level of active MMP-2 (64 kD), the high dose of TIMP-2 (> or = 200 ng/ml) decreased the level of active MMP-2 (64 kD). Taken together, we suggest that the induction of TIMP-2 by cholesterol depletion leads to the conversion of proMMP-2 (72 kD) into active MMP-2 (64 kD) in human dermal fibroblasts.
Anthracenes/pharmacology ; Butadienes/pharmacology ; Cells, Cultured ; Child ; Child, Preschool ; Cholesterol/metabolism/*physiology ; Cyclodextrins/pharmacology ; Enzyme Inhibitors/pharmacology ; Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors/physiology ; Fibroblasts/*drug effects/*metabolism/ultrastructure ; Humans ; Immunoblotting ; Immunoprecipitation ; JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors/physiology ; Matrix Metalloproteinase 2/*metabolism ; Microscopy, Electron, Transmission ; Nitriles/pharmacology ; Tissue Inhibitor of Metalloproteinase-2/*metabolism