Cells, Cultured ; Chemokine CCL2 ; biosynthesis ; genetics ; Endothelial Cells ; metabolism ; Humans ; Mitogen-Activated Protein Kinases ; biosynthesis ; genetics ; RNA, Messenger ; genetics ; Umbilical Veins ; cytology ; p38 Mitogen-Activated Protein Kinases

OBJECTIVEMicroRNAs (miRNAs or miRs) play critical roles in the fibrotic process in different organs. We summarized the latest research progress on the roles and mechanisms of miRNAs in the regulation of the molecular signaling pathways involved in fibrosis.

DATA SOURCESPapers published in English from January 2010 to August 2015 were selected from the PubMed and Web of Science databases using the search terms "microRNA", "miR", "transforming growth factor β", "tgf β", "mitogen-activated protein kinase", "mapk", "integrin", "p38", "c-Jun NH2-terminal kinase", "jnk", "extracellular signal-regulated kinase", "erk", and "fibrosis".

STUDY SELECTIONArticles were obtained and reviewed to analyze the regulatory effects of miRNAs on molecular signaling pathways involved in the fibrosis.

RESULTSRecent evidence has shown that miRNAs are involved in regulating fibrosis by targeting different substrates in the molecular processes that drive fibrosis, such as immune cell sensitization, effector cell activation, and extracellular matrix remodeling. Moreover, several important molecular signaling pathways involve in fibrosis, such as the transforming growth factor-beta (TGF-β) pathway, mitogen-activated protein kinase (MAPK) pathways, and the integrin pathway are regulated by miRNAs. Third, regulation of the fibrotic pathways induced by miRNAs is found in many other tissues in addition to the heart, lung, liver, and kidney. Interestingly, the actions of many drugs on the human body are also induced by miRNAs. It is encouraging that the fibrotic process can be blocked or reversed by targeting specific miRNAs and their signaling pathways, thereby protecting the structures and functions of different organs.

CONCLUSIONSmiRNAs not only regulate molecular signaling pathways in fibrosis but also serve as potential targets of novel therapeutic interventions for fibrosing diseases.

Animals ; Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Fibrosis ; genetics ; metabolism ; Humans ; MicroRNAs ; genetics ; Mitogen-Activated Protein Kinases ; genetics ; metabolism ; Transforming Growth Factor beta ; genetics ; metabolism

OBJECTIVETo explore the functional effects of MAPK pathway in the pathogenesis of human osteosarcoma.

METHODSGene microarray (Human Genome U133A, Affymetrix) was used to screen the differential expression of genes involved in MAPK pathway between osteosarcoma cell lines and 3 osteoblastic cell lines. KEGG metabolic pathway analysis was performed among significantly increased or decreased genes using the MATLAB software. Immunohistochemical technique was used to detect the expressions of ERK1/2, JNK and p38 proteins among 48 osteosarcoma and benign 24 osteoblastic tumor samples.

RESULTSUsing an entrance limit of > or = 2.0, 18 differentially expressed MAPK pathway-related genes were selected (10 up-regulated, 8 down-regulated) to mapped to the MAPK pathway of KEGG which are all important node genes. The positive rates of ERK1/2, JNK and p38 proteins were 83.3% (40/48), 72.9% (35/48) and 85.4% (41/48) in osteosarcomas,and 12.5% (3/24), 8.3% (2/24) and 16.7% (4/24) in the control group, respectively. The positive rates and expression intensities were statistically different between the 2 groups (P<0.01).

CONCLUSIONMAPK pathway plays an important role in the pathogenesis of osteosarcoma. ERK, JNK and p38 form an intercoordinating network and regulate the cell proliferation, differentiation, apoptosis, invasion and migration in osteosarcoma.

Adolescent ; Adult ; Aged ; Bone Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Child ; Female ; Gene Expression Profiling ; Humans ; JNK Mitogen-Activated Protein Kinases ; metabolism ; Male ; Middle Aged ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Mitogen-Activated Protein Kinases ; metabolism ; Oligonucleotide Array Sequence Analysis ; Osteoblastoma ; genetics ; metabolism ; pathology ; Osteosarcoma ; genetics ; metabolism ; pathology ; Signal Transduction ; Young Adult ; p38 Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVETo investigate the effect of interleukin-6 (IL-6) on the human growth hormone (hGH) gene expression in a rat somatotropic pituitary cell line MtT/S.

METHODSThe plasmids containing various lengths of hGH gene 5'-promoter fragments were constructed. Stably transfected MtT/S cells were created by cotransfecting the above plasmids and pcDNA3. 1(+) with DMRIE-C transfection reagent After the administration of these cells with IL-6 and/or various inhibitors of signaling transduction pathways, the luciferase activities in MtT/S cells lysis were assayed to demonstrate the effects of IL-6 on hGH gene promoter activity and possibly involved mechanism.

RESULTSThe 10(3) U/mL IL-6 stimulated GH secretion and synthesis, and promoted the 5'-promoter activity of GH gene in stably transfected MtT/SGL cells with the action of 1.69 times above the control. Among inhibitors of signaling transduction pathways, mitogen-activated protein kinase kinase (MAPKK/MEK) inhibitor PD98059 (40 micromol/L) and p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 (5 micromol/L) completely blocked the stimulatory effect of IL-6. Western blot analysis further confirmed the activation of phosphorylated MEK and p38 MAPK in MtT/SGL cells. Neither over-expression of Pit-1 nor inhibition of Pit-1 expression affected IL-6 induction of hGH promoter activity. A series of deletion constructs of hGH promoter were created to identify the DNA sequence that mediated the effect of IL-6. The results showed that the stimulatory effect of IL-6 was abolished following deletion of the -196 to - 132 bp fragment.

CONCLUSIONSIL-6 promotes GH secretion and synthesis by rat MtT/S somatotroph cells. The stimulatory effect of IL-6 on hGH gene promoter appears to require the activation of MEK and p38 MAPK, and a fragment of promoter sequence that spans the - 196 to - 132 bp of the gene, but may be unlinked with Pit-1 protein.

Animals ; Cell Line ; Gene Expression Regulation ; Human Growth Hormone ; genetics ; metabolism ; Humans ; Interleukin-6 ; genetics ; metabolism ; JNK Mitogen-Activated Protein Kinases ; genetics ; metabolism ; MAP Kinase Signaling System ; physiology ; Mitogen-Activated Protein Kinase Kinases ; genetics ; metabolism ; Promoter Regions, Genetic ; Rats ; Somatotrophs ; cytology ; metabolism ; p38 Mitogen-Activated Protein Kinases ; genetics ; metabolism

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 expression of Smad4 in non-small cell lung cancer (NSCLC), its correlation with MAPK (mitogen activated protein kinase) and their clinical significance in NSCLC.

METHODSWestern blotting and RT-PCR were employed to test 42 resected lung cancers and normal lung tissues for the expression of Smad4. Imunohistochemistry was used to detect Smad4 and subtribes of MAPK in 71 paraffin samples.

RESULTSThe level of protein and mRNA expression of Smad4 in lung cancer tissues were 0.2092 +/- 0.1308 and 0.3986 +/- 0. 1982, respectively, lower than those in normal tissues (0.7852 +/- 0.4386 and 1.1206 +/- 0.6772, P < 0.05). The expression of p38, ERK1 and Smad4 was associated with TNM staging (P = 0.000, 0.000 and 0.005, respectively) and JNK1 with tumor location (P = 0.028) and staging (P = 0.000). There was a correlation between p38 and Smad4 (P = 0.000). The expression of Smad4 (P = 0.0001), p38 (P = 0.0000) and JNK1 (P = 0.0208), tumor differentiation (P = 0.0059) and staging (P = 0.0000) were significantly correlated with prognosis of NSCLC by univariate analysis. Smad4 (P = 0.019), p38 (P = 0.044), tumor differentiation (P = 0.003), and staging (P = 0.020) were correlated with prognosis tested by multivariable analysis. Taking p38 and Smad4 together, we found that the negative expression of p38 and positive expression of Smad4 were associated with a better prognosis of NSCLC (P = 0.000).

CONCLUSIONSmad4 could be of importance for the initiation and development of NSCLC. There is a significant correlation between main proteins of TGF-beta/smad4 and those of ras-MAPK signal transduction pathways. The expression of Smad4 is inhibited by p38. Smad4, as well as p38, tumor differentiation and staging can be used as prognostic factors of NSCLC.

Adult ; Aged ; Blotting, Western ; Carcinoma, Non-Small-Cell Lung ; metabolism ; pathology ; Cell Differentiation ; Female ; Humans ; Lung Neoplasms ; genetics ; metabolism ; pathology ; Male ; Middle Aged ; Mitogen-Activated Protein Kinase 3 ; genetics ; metabolism ; Mitogen-Activated Protein Kinase 8 ; genetics ; metabolism ; Mitogen-Activated Protein Kinases ; genetics ; metabolism ; Neoplasm Staging ; Prognosis ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; Smad4 Protein ; genetics ; metabolism ; physiology ; p38 Mitogen-Activated Protein Kinases ; genetics ; 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

OBJECTIVETo investigate the effect of p38 mitogen-activated protein kinase (p38MAPK) on the expression of COX-2 and caspase-3 in the substania nigra (SN) of mice with MPTP-induced Parkinson disease (PD).

METHODSC57BL/CN mice were treated with MPTP to prepare a subacute PD model, and their behavioral changes following the treatment were observed. Immunohistochemistry and Western blotting were performed to detect the expression of tyrosine hydroxylase (TH), COX-2 and phosphorylation of P38MAPK in the SN and their changes following treatment with SB203580, a specific inhibitor of P38MAPK.

RESULTSThe 7-day model group showed typical symptoms of PD with decrements of TH-positive neurons and TH protein level in the SN of the midbrain by about 65% and 75%, respectively (P<0.01). In the 3-day model group, the COX-2-, caspase-3- and phosphorylated P38MAPK-immunoreactive cells and their protein levels in the SN increased markedly with obvious loss of TH-positive neurons. Administration of SB203580 obviously lessened the above changes (P<0.01).

CONCLUSIONP38MAPK regulates the inflammation and apoptosis in the SN of the mouse model of subacute PD, and SB203580 may provide some neuroprotective effect.

Animals ; Caspase 3 ; genetics ; metabolism ; Cyclooxygenase 2 ; genetics ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Parkinson Disease ; metabolism ; Signal Transduction ; Substantia Nigra ; metabolism ; p38 Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVETo investigate the effect of cytoskeleton reorganization inhibition with RNA interference on the activation of extracellular signal-regulated kinase (ERK1/2) in primary osteoblasts induced by fluid shear stress (FSS).

METHODSBALB/c mouse primary cultured osteoblasts were isolated by enzyme digestion technique. Osteoblasts were treated with LIM domain kinase 2 (LIM-2) specific siRNA or negative control siRNA, and then were loaded or unloaded by FSS of 1.2 Pa for 0, 5, 15, 30 and 60 min, respectively. The Western blotting was performed to detect the protein expression levels of P-ERK1/2 and ERK1/2, respectively. Two-way ANOVA and one-way ANOVA were used in data analysis.

RESULTSFSS loading for different time (0, 5, 15, 30, 60 min) treated with negative RNA inteference had significant effect on the levels of P-ERK/ERK ratio (0.047 ± 0.031, 0.253 ± 0.137, 0.390 ± 0.155, 0.613 ± 0.123, 0.680 ± 0.108, respectively, P < 0.01). Statistical analysis showed that there was significant interaction between FSS and cytoskeleton reorganization inhibition treated with RNA inteference on the levels of P-ERK/ERK ratio (P < 0.01). The levels of P-ERK/ERK ratio increased when osteoblasts were loaded for 5 - 15 min (0.623 ± 0.129 and 0.623 ± 0.064, respectively, P < 0.05) and returned to baseline at 30 min (0.333 ± 0.086), and then reached the peak at 60 min (0.667 ± 0.064, P < 0.01).

CONCLUSIONSFSS could activate ERK1/2 rapidly in primary cultured osteoblasts. Cytoskeleton reorganization inhibition treated with RNA interference speeded-up the activation of ERK1/2 by FSS, which could increase the sensitivity of ERK1/2 to FSS.

Animals ; Cells, Cultured ; Cytoskeleton ; metabolism ; physiology ; Lim Kinases ; genetics ; metabolism ; Mechanotransduction, Cellular ; Mice ; Mice, Inbred BALB C ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Osteoblasts ; cytology ; enzymology ; Phosphorylation ; RNA Interference ; RNA, Small Interfering ; Stress, Mechanical

This study was aimed to investigate the activation of P38MAPK/STAT3 and expression of telomerase reverse transcriptase during sodium nitroprusside (SNP) inducing apoptosis of human leukemia cell line K562 and to explore the molecular mechanisms of SNP-inducing apoptosis in K562 cells. The K562 cell were treated with different concentrations of SNP and were cultured for different time. Cell apoptosis was analysed by cell morphology, DNA agarose gel electrophoresis, DNA content, and Annexin-V/PI labeling method. The TdT-mediated dUTP nick end labeling (TUNEL) assay was used to quantitate the in situ cell apoptosis. The expressions of phosphorylated p38MAPK or STAT3 were analysed by flow cytometry, while the expression of hTERT mRNA in transcriptional level was measured by fluorescence quantitative RT-PCR. The results showed that SNP inhibited K562 cell growth. The K562 cell apoptosis was confirmed by typical cell morphology and DNA fragment, peak of sub-G1 phase, TUNEL and Annexin-V/PI labeling. A majority of K562 cells were arrested in G0/G1 phase. After treatment with SNP at 0.5-3.0 mmol/L, the expression of phosphorylated-P38MAPK and phosphorylated-STAT3 increased first and decreased afterwards. Incubation of K562 cell with SNP (2 mmol/L) could increase the expression of phosphorylated-P38MAPK and phosphorylated-STAT3 at 12 hours and 24 hours respectively, and down-regulated at 72 hours and 48 hours. SNP could decrease the expression of hTERT-mRNA in time-and dose-dependent manner. It is concluded that SNP can significantly induce K562 cells apoptosis, its mechanism may be related to the activation of P38MAPK and suppression of phosphorylated-STAT3 and hTRET-mRNA.
Apoptosis ; drug effects ; Humans ; K562 Cells ; Nitroprusside ; pharmacology ; RNA, Messenger ; biosynthesis ; genetics ; STAT3 Transcription Factor ; genetics ; metabolism ; Telomerase ; biosynthesis ; genetics ; p38 Mitogen-Activated Protein Kinases ; genetics ; metabolism