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

OBJECTIVESTo investigate the effects of FAK-related non-kinase (FRNK) on the apoptosis of hepatic stellate cells (HSC) in vitro and on the extracellular signal-regulated kinase (ERK) signal transduction pathway.

METHODSHSC were stimulated by fibronectin (FN), and then they were transfected with FAK-related non-kinase (FRNK) plasmids mediated by cationic liposome. The apoptosis of FRNK-induced HSC was examined by annexin-V/propidium iodide double-labeled flow cytometry (FCM), gel electrophoresis and transmission electron microscopy. Levels of FRNK, FAK, p-FAK (Tyr397), ERK1 and p-ERK in HSC were assayed by Western blot on the protein level, and by RT-PCR on the mRNA level.

RESULTSThe expression of FRNK was enhanced after FRNK plasmids were transiently transfected into the HSC. The apoptotic rate of the HSC exposed to FRNK plasmids for 48 h was higher than that in the non-FRNK plasmid group (25.37%+/-1.92% vs 9.28%+/-1.05%, P less than 0.01), and was accompanied by a significantly higher activity of caspase-3 both in the protein and in the mRNA levels [(264.17+/-12.60 vs 185.82+/-9.69), P less than 0.01; (4.19+/-0.48 vs 1.07+/-0.27), P less than 0.01]. After exposure of HSC to FRNK plasmids, compared with the non-FRNK plasmid group, the expressions of p-FAK, ERK1 and p-ERK in protein and mRNA levels were lower; on the contrary, compared with the control group, the expressions of p-FAK, ERK1 and p-ERK in the FN group were higher.

CONCLUSIONThe expression of FRNK was enhanced and the phosphorylation of FAK was inhibited after FRNK was transiently transfected into HSC in vitro. FRNK induces apoptosis of HSC. FAK-ERK signal transduction pathway perhaps is involved in the process.

Apoptosis ; Cell Line ; Cell Proliferation ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Hepatic Stellate Cells ; metabolism ; pathology ; Humans ; Protein-Tyrosine Kinases ; genetics ; metabolism ; RNA, Messenger ; genetics ; Signal Transduction

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 explore the effects of advanced oxidation protein products (AOPP) on expressions of stromal cell-derived factor-1alpha (SDF-1alpha) in ECV304 cells and the signal pathway that mediated the effects.

METHODSAOPP-BSA was made from bovine serum albumin (BSA) and sodium hypochlorite. After treated with AOPP-BSA of different concentrations (50, 100, 200 micromol/L), the expressions of SDF-1alpha mRNA in ECV304 cells were measured by reverse transcription-polymerase chain reaction (RT-PCR) and the expressions of SDF-1alpha protein and the levels of phosphorylated extracellular signal-regulated kinase (ERK) in ECV304 cells were analyzed by Western blot. In inhibition test, U0126, the special inhibitor of ERK of different concentrations (0.1, 1, 10 rmol/L) were added into ECV304 cells culture media for 1 hour, then the cells were treated with AOPP-BSA for 24 hours, at last the protein levels in supernatant were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTSAOPP-BSA obviously promoted the expressions of SDF-1alpha mRNA and increased the levels of SDF-1beta protein of ECV304 cells in dose-dependent manner (all P < 0.01), after 15 minutes treated with 200 micromol/L AOPP-BSA, the levels of phosphorylated ERK of ECV304 cells increased significantly (P < 0.01). When the ERK pathway was blocked by U0126, the promoting effects of AOPP-BSA on expressions of SDF-la protein in ECV304 cells were significantly inhibited in dose-dependent manner (P < 0.05).

CONCLUSIONAOPP induced the expression of SDF-la of ECV304 cells, ERK signal pathway is an important pathway that mediated the effects.

Advanced Oxidation Protein Products ; pharmacology ; Cell Line ; Chemokine CXCL12 ; metabolism ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Humans ; MAP Kinase Signaling System ; Oxidative Stress ; Phosphorylation ; RNA, Messenger ; genetics

OBJECTIVETo study the expressions of Erk1/2 and PKB/Akt in the corpus cavernosum of castrated rats and investigate their action mechanism in the development of erectile dysfunction (ED) after castration.

METHODSWe randomly divided 20 eight-week-old SD rats into Groups A (sham-operation) and B (castration), and, 4 weeks after the operation, determined the level of serum testosterone (T) and the expressions of P-Erk1/2 and P-PKB/Akt proteins (integrated optical density/area, IA/area) and those of Erk1/2 and PKB/Akt mRNA (Marker: GAPDH) in the corpus cavernosum of the rats by immunohistochemical staining and RT-PCR.

RESULTSFour weeks after the operation, the serum T level was significantly decreased in Group B in comparison with A ([10.090 +/- 3. 026] nmol/L versus [1.339 +/- 0.642] nmol/L, P < 0.05). Erk1/2 and PKB/Akt expressed in the corpus cavernosum of both groups of rats. The expressions of Erk1 and Erk2 mRNA and P-Erk1/2 were significantly higher in Group B (0. 840 +/- 0.062, 0.876 +/- 0.141 and 0.142 +/- 0.020) than in A (0.479 +/- 0.090, 0.599 +/- 0.100 and 0.119 +/- 0.029) (P < 0.05). But no statistically significant differences were found in the expressions of PKB/Akt mRNA and P-PKB/Akt between Groups B (0.974 +/- 0.040 and 0.164 +/- 0.036) and A (0.942 +/- 0.054 and 0.162 +/- 0.025) (P < 0.05).

CONCLUSIONErk1/2 and PKB/Akt expressed in the penile tissues of both castrated and sham-operation rats. The increased expression of P-Erk1/2 in the corpus cavernosum may be involved in the development of ED in castrated rats.

Animals ; Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Male ; Orchiectomy ; Penis ; metabolism ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley

Extracellular Signal-Regulated MAP Kinases ; metabolism ; Glomerular Mesangium ; immunology ; Glycosylation ; Humans ; Immunoglobulin A ; metabolism ; Phosphorylation ; Receptors, Fc ; analysis ; genetics ; Receptors, Transferrin ; analysis ; genetics

OBJECTIVETo investigate the expression and activation of extracellular signal-regulated kinases (ERK) in myocardial hypertrophy of spontaneously hypertensive rats (SHR) with different ages.

METHODSSHRs and Wistar Kyoto (WKY) rats were divided into 4 groups (5-, 8-,14-, 24-week old) respectively. The ratio of left ventricle weight to body weight (LVW/BW) was measured as the indicator of myocardial hypertrophy. The basal ERK expression (b-ERK) and phosphorylated-ERK (p-ERK) in myocardial tissue were examined by Western blot.

RESULTThe blood pressure of SHR was significantly higher than that of age-matched WKY rats from 8-week-old (P<0.001). The ratio of LVW/BW in SHR was increased significantly from 14-week-old (P<0.01). There was no significant difference of b-ERK expression between SHR and age-matched WKY rats. The p-ERK level of 5-week-old SHR was similar to that of 5-week-old WKY rats. The p-ERK level of SHR was significantly higher than that of age-matched WKY rats from 8-week-old to 24-week-old (P<0.01). The ratio of LVW/BW was positively related to p-ERK level but not related to b-ERK.

CONCLUSIONThe activation of ERK may play an important role in the development of myocardial hypertrophy caused by hypertension.

Age Factors ; Animals ; Cardiomyopathy, Hypertrophic ; pathology ; Extracellular Signal-Regulated MAP Kinases ; biosynthesis ; genetics ; metabolism ; Hypertension ; enzymology ; pathology ; Male ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY

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

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

OBJECTIVETo study the expression and possible roles of proto-oncogene c-erbB2 during the initiation growth of primordial follicles.

METHODSOvaries were collected from 2-day-old SD rats and cultured in the Waymouth culture system. In-situ hybridization, RT-PCR and immunohistochemistry were performed to assess the expressions of c-erbB2 mRNA and protein during the initiation growth of primordial follicles and after the effect of EGF. Western blot was used to observe the PCNA, p-ERK1/2 contents and correlation analysis was used to study the correlation relationship between contents of p-ERK1/2 and expressions of c-erbB2 mRNA at the same time of the primordial follicles growth.

RESULTSPCNA protein levels appeared to be more intense during the initiation growth of primordial follicles, EGF could promote the proliferation and differentiation of the primordial follicles. c-erbB2 mRNA existed in the oocytes endochylema and ErbB2 existed in the oocytes membrane, the expressions of c-erbB2 mRNA and ErbB2 appeared to be more intense when primordial follicles were cultured for 8 d than cultured for 0 d in the Waymouth culture system and were further increased with 50 ng/ml EGF for 4 d and 8 d. The same results were observed by RT-PCR, too. p-ERK1/2 protein levels were consistent with the changes of c-erbB2 mRNA and protein. Furthermore, Spearman rank correlation analysis showed there was a significant positive correlation relationship between the changes of p-ERK1/2 and the changes of c-erbB2 mRNA during the primordial follicles growth and after the effect of EGF (rs = 0.900, P < 0.05).

CONCLUSIONIt was suggested that proto-oncogene c-erbB2 may be play an important role during the initiation growth of primordial follicles with EGF, and it is indirectly suggested that c-erbB2 promotes the development of the primordial follicles via ERK-MAPK signal transduction.

Animals ; Animals, Newborn ; Epidermal Growth Factor ; pharmacology ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Female ; Organ Culture Techniques ; Ovarian Follicle ; growth & development ; Ovary ; growth & development ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor, ErbB-2 ; genetics ; metabolism ; Signal Transduction