Role Of MAPK Signaling Pathway Research Articles

Transcriptomic characteristics analysis of bone from chronic osteomyelitis

To explore the molecular mechanism of chronic osteomyelitis and to clarify the role of MAPK signal pathway in the pathogenesis of chronic osteomyelitis, by collecting and analyzing the transcriptional information of bone tissue in patients with chronic osteomyelitis. Four cases of traumatic osteomyelitis in limbs from June 2019 to June 2020 were selected, and the samples of necrotic osteonecrosis from chronic osteomyelitis (necrotic group), and normal bone tissue (control group) were collected. Transcriptome information was collected by Illumina Hiseq Xten high throughput sequencing platform, and the gene expression in bone tissue was calculated by FPKM. The differentially expressed genes were screened by comparing the transcripts of the Necrotic group and control group. Genes were enriched by GO and KEGG. MAP3K7 and NFATC1 were selected as differential targets in the verification experiments, by using rat osteomyelitis animal model and immunohistochemical analysis. A total of 5548 differentially expressed genes were obtained by high throughput sequencing by comparing the necrotic group and control group, including 2701 up-regulated and 2847 down-regulated genes. The genes enriched in MAPK pathway and osteoclast differentiation pathway were screened, the common genes expressed in both MAPK and osteoclast differentiation pathway were (inhibitor of nuclear factor κ subunit Beta, IκBKβ), (mitogen-activated protein kinase 7, MAP3K7), (nuclear factor of activated t cells 1, NFATC1) and (nuclear factor Kappa B subunit 2, NFκB2). In rat osteomyelitis model, MAP3K7 and NFATC1 were highly expressed in bone marrow and injured bone tissue. Based on the transcriptome analysis, the MAPK signaling and osteoclast differentiation pathways were closely related to chronic osteomyelitis, and the key genes IκBKβ, MAP3K7, NFATC1, NFκB2 might be new targets for clinical diagnosis and therapy of chronic osteomyelitis.

Identification of recurrent BRAF non-V600 mutations in intraductal carcinoma of the prostate in Chinese populations

While BRAF alterations have been established as a driver in various solid malignancies, the characterization of BRAF alterations in prostate cancer (PCa) has not been thoroughly interrogated. By bioinformatics analysis, we first found that BRAF alterations were associated with advanced PCa and exhibited mutually exclusive pattern with ERG alteration across multiple cohorts. Of the most interest, recurrent non-V600 BRAF mutations were found in 3 of 21 (14.3 %) PCa patients demonstrating IDC-P morphology. Furthermore, experimental overexpression of BRAFK601E and BRAFL597R exhibited emergence of oncogenic phenotypes with intensified MAPK signaling in vitro, which could be targeted by MEK inhibitors. Comparison of the incidence of BRAF alterations in IDC-P between western and Chinese ancestry revealed an increased prevalence in the Chinese population. The BRAF mutation may represent important genetic alteration in a subset of IDC-P, highlighting the role of MAPK signaling pathway in this subtype of PCa. To the best of knowledge, this is the first description of non-V600 BRAF mutation in setting of IDC-P, which may in part explain the aggressive phenotype seen in IDC-P and could also bring more treatment options for PCa patients with IDC-P harboring such mutations.

MAPK: A Key Player in the Development and Progression of Stroke.

Stroke is a complex disease caused by genetic and environmental factors, and its etiological mechanism has not been fully clarified yet, which brings great challenges to its effective prevention and treatment. MAPK signaling pathway regulates gene expression of eukaryotic cells and basic cellular processes such as cell proliferation, differentiation, migration, metabolism and apoptosis, which are considered as therapeutic targets for many diseases. Up to now, mounting evidence has shown that MAPK signaling pathway is involved in the pathogenesis and development of ischemic stroke. However, the upstream kinase and downstream kinase of MAPK signaling pathway are complex and the influencing factors are numerous, the exact role of MAPK signaling pathway in the pathogenesis of ischemic stroke has not been fully elucidated. MAPK signaling molecules in different cell types in the brain respond variously after stroke injury, therefore, the present review article is committed to summarizing the pathological process of different cell types participating in stroke, discussed the mechanism of MAPK participating in stroke. We further elucidated that MAPK signaling pathway molecules can be used as therapeutic targets for stroke, thus promoting the prevention and treatment of stroke.

The expression of MAPK signaling pathways in conjunctivochalasis.

This study investigated the potential role of MAPK signaling pathways in conjunctivochalasis (CCH). Twenty loose conjunctival biopsy samples from 20 CCH and 15 conjunctival biopsy samples from 15 normal controls (CON) were collected. The conjunctival fibroblasts were cultured in vitro. Immunofluorescence, ELISA, Western blot and reverse transcription-polymerase chain reaction (RT-PCR) were used. Our results showed that the expression of p-ERK, p-JNK, and p-p38 in CCH conjunctiva was significantly higher than that in CON group. The expression of p38 MAPK, JNK, and ERK proteins in CCH fibroblasts was significantly higher than that in CON group. The total expression of MAPK mRNA in CCH fibroblasts was significantly higher than that in CON group. The activated forms of p38 MAPK, JNK, and ERK proteins and mRNAs might up-regulate the expression of MMPs in CCH loose conjunctival tissue and fibroblasts, causing the degradation of collagen fibers and elastic fibers and promoting the occurrence of CCH. Our results deepen the understanding of CCH pathological mechanism.

The role of MAPK signaling pathway in formation of EMT in oral squamous carcinoma cells induced by TNF-α.

To study the role of MAPK signaling pathway in the development of Epithelial-mesenchymal transition in oral squamous cell carcinoma induced by inflammatory factor TNF-α. After the action of TNF-α, the expression of JNK, ERK, P38 in MAPK signaling pathway increased and the expression of E-cadherin, Claudin1 decreased significantly compared to the normal control group. After the addition of corresponding inhibitor, the expression of JNK, ERK, P38 decreased and the expression of E-cadherin, Claudin1 increased compared with TNF-α group. TNF-α regulated the role of EMT in promoting the invasion and metastasis of oral squamous carcinoma cells through MAPK signaling pathway.

The role of MAPK signaling pathway in selenium amelioration of high fat/high cholesterol diet-induced tauopathy in rats

BackgroundMAP kinases, CREB, and Tau are signaling molecules among downstream synaptic targets involved in synaptic function, memory formation and cognition. PurposeHere we investigate the neuro-protective effect of selenium in HFHCD induced tauopathy and cognitive impairment in rats. The study was focused on the effects on synaptic plasticity related molecules in hippocampus, which in turn may be the mechanism responsible for underlying behavior alterations. MethodRats were divided into 2 main groups: one fed with normal rat chow diet and the other with HFHCD for 6 weeks. Every group was subdivided into three subgroups, non-treated, low dose Se (200 μg/kg) and high dose Se (400 μg/kg). The cognitive behaviors of the rats were tested using the Morris Water Maze test, hole board and conditioned avoidance tests. ResultsDaily administration of Se decreased the observed memory impairment induced by HFHCD as measured by behavioral tests. It significantly alleviated oxidative stress and restored protein expression of cyclic AMP response element protein (CREB) and brain derived neurotrophic factor (BDNF) and reduced p-Tau in the hippocampus. ConclusionSe reversed HFHCD-induced cognitive impairments via decrease expression of p38 MAPK that phosphorylate and aggregate Tau protein. Addition, It restored neuronal plasticity through increasing the expression of BDNF, and CREB in the hippocampus; thus, it can be considered as a possible beneficial therapeutic approach for prevention and treatment of HFHCD induced tauopathy and cognitive impairment, further studies are warranted in this field.

TMEM100 mediates inflammatory cytokines secretion in hepatic stellate cells and its mechanism research

Recent studies have shown that Transmembrane protein 100 (TMEM100) is a gene at locus 17q32 encoding a 134-amino acid protein with two hypothetical transmembrane domainsa, and first identified as a transcript from the mouse genome. As a downstream target gene of bone morphogenetic protein (BMP)-activin receptor-like kinase 1 (ALK1) signaling, it was activated to participate in inducing arterial endothelium differentiation, maintaining vascular integrity, promoting cell apoptosis, inhibiting metastasis and proliferation of cancer cells. However, evidence for the function of TMEM100 in inflammation is still limited. In this study, we explore the role of TMEM100 in inflammatory cytokine secretion and the role of MAPK signaling pathways in tumor necrosis factor-alpha (TNF-α)-induced TMEM100 expression in LX-2 cells. We found that the expression of TMEM100 was decreased markedly in human liver fibrosis tissues, and its expression was also inhibited in LX-2 cells induced by TNF-α, suggesting that it might be associated with the development of inflammation. Therefore, we demonstrated that overexpression of TMEM100 by transfecting pEGFP-C2-TMEM100 could lead to the down-regulation of IL-1β and IL-6 secretion. Moreover, we found that expression changes of TMEM100 could be involved in inhibition or activation of MAPK signaling pathways accompanied with regulating phosphorylation levels of ERK and JNK protein in response to TNF-α. These results suggested that TMEM100 might play an important role in the secretion of inflammatory cytokines (IL-1β and IL-6) of LX-2 cells induced by TNF-α, and MAPK (ERK and JNK) signaling pathways might participate in its induction of expression.

Molecular mechanisms of the juvenile form of Batten disease: important role of MAPK signaling pathways (ERK1/ERK2, JNK and p38) in pathogenesis of the malady

BackgroundMutations in the CLN3 gene lead to so far an incurable juvenile-onset neuronal ceroid lipofuscinosis (JNCL) or Batten disease that starts at the age of 4–6 years with a progressive retinopathy leading to blindness. Motor disturbances, epilepsy and dementia manifest during several following years. Most JNCL patients carry the same 1.02-kb deletion in the CLN3 gene, encoding an unusual transmembrane protein, CLN3 or battenin.ResultsBased on data of genome-wide expression profiling in CLN3 patients with different rate of the disease progression [Mol. Med., 2011, 17: 1253–1261] and our bioinformatic analysis of battenin protein-protein interactions in neurons we propose that CLN3 can function as a molecular chaperone for some plasma membrane proteins, being crucially important for their correct folding in endoplasmic reticulum. Changes in spatial structure of these membrane proteins lead to transactivation of the located nearby receptors. Particularly, CLN3 interacts with a subunit of Na/K ATPase ATP1A1 which changes its conformation and activates the adjacent epidermal growth factor receptor (EGFR). As a result, a large amount of erroneously activated EGFR generates MAPK signal cascades (ERK1/ERK2, JNKs and p38) from cell surface eventually causing neurons’ death.ConclusionsMolecular mechanism of the juvenile form of Batten disease (JNCL), which is based on the excessive activation of signaling cascades in a time of the radical increase of neuronal membranes’ area in the growing brain, have been proposed and substantiated. The primary cause of this phenomenon is the defective function of the CLN3 protein that could not act properly as molecular chaperone for some plasma membrane proteins in the endoplasmic reticulum. The incorrect three-dimensional structure of at least one such protein, ATP1A1, leads to unregulated spontaneous and repetitive activation of the SRC kinase that transactivates EGFR with the subsequent uncontrolled launch of various MAPK cascades. Possible ways of treatment of patients with JNCL have been suggested.ReviewersThis article was reviewed by Konstantinos Lefkimmiatis, Eugene Koonin and Vladimir Poroikov.

Role of MAPK signaling pathway in epithelial-mesenchymal transition of type II alveolar epithelial cells induced by Paraquat

Objective: To investigate the roles of p38 mitogen-activated protein kinases (p38 MAPK) , extracellular regulated protein kinases (ERK) and c-Jun N-tenninal kinases (JNK) of MAPK signaling pathway in Paraquat-induced epithelial to mesenchymal transition (EMT) of type II alveolarepithelial cells. Methods: RLE-6NT cells were incubated with different concentrations of PQ (0, 25, 50, 100μmol/L) for 6, 12 and 24 h. Cell morphology alteration was observed under phase-contrast microscopy. Cell viability was determined using an MTT assay. Cell migration ability was detected using scratch wound assay. Protein expression of P-p38 MAP, P-Erk1/2, P-JNK, E-cad, ZO-1, Vimentin and а-SMA were detected by western blot. The level of genes related to fibrosis (COL-I, COL-III, FN and FSP-1) were analyzed via quantitative real-time RT-PCR. Results: Cell morphology started to undergo EMT changes with a phenotype characteristic of mesenchymal cells, including an elongated shape and a lack of tight cell-cell adhesions induced by 100μmol/L PQ treatment in a time-dependent manner. MTT showed that cell viability decreased with increasing PQ concentration (50、100、200、300 μmol/L PQ treatment for 24 h) and increasing treatment time (200 μmol/L PQ treatment for 6, 12, 24, 36, 48 h) . Compared to control group, the expressions of the epithelial phenotype marker E-cad and ZO-1 significantly decreased with PQ treatment (50, 100μmol/L) in a time-dependent manner (P<0.05) . Additionally, the level of the mesenchymal marker (a-SMA, vimentin) dramatically increased with PQ treatment in the same concentration-and time-dependent manner (P<0.05) . Cell migration ability was markedly increased after 24 h of 100 μmol/L PQ treatment compared to control (P<0.05) . The phosphorylated forms of p38 MAPK, Erk1/2, and JNK were increased at 24 h after stimulation with PQ (P<0.05) . This PQ induced (100 μmol/L) phosphorylation was markedly attenuated in the presence of the p38 MAPK, ERK and JNK inhibitors (SB-203580, SP-600125 and PD98059) respectively. Furthermore, RT-PCR showed that PQ significantly induced the upregulation expression of COL I and III mRNA, Fn, and FSP-1 mRNA (P<0.05) . Conclusion: PQ-induced pulmonary fibrosis occurs via EMT, which is mediated by the MAPK pathway.

Disorder of sex development 46,XY associated with mutations in the gene MAP3K1. The report of clinical cases

The disorders of sex development (DSD) 46,XY may be caused by mutations in a number of genes involved in the gonadal differentiation. The XY sex inversion can be also due to disturbances at the level of mitogen-activated protein kinase (MAPK) kinase kinase 1 gene (MAP3K1) and MAPK-signaling pathway. During the last decade, the involvement of the MAPK pathway in the SRY gene up-regulation during the formation of male gonadal sex in mammals has been demonstrated. The role of MAPK-signaling pathway in the human sex determination is not fully understood. Probably, MAP3K1 and the MAPK-signaling pathway are one of the genetic pathways controlling normal development of human testis. So far, several families and sporadic cases of 46,XY DSD due to mutations in MAP3K1 gene have been reported in the literature. Clinical presentation of DSD in these patients varies from female phenotype with normal externalia to male phenotype with hypospadias. We describe rare cases of the DSD 46,XY (a family case of DSD in uterine sisters and a sporadic case) with mutations in the MAP3K1 gene that haven’t been previously described. The article also presents brief literature review on this pathology.

Disorder of sex development 46,XY associated with mutations in the gene MAP3K1. The report of clinical cases

The disorders of sex development (DSD) 46,XY may be caused by mutations in a number of genes involved in the gonadal differentiation. The XY sex inversion can be also due to disturbances at the level of mitogen-activated protein kinase (MAPK) kinase kinase 1 gene (MAP3K1) and MAPK-signaling pathway. During the last decade, the involvement of the MAPK pathway in the SRY gene up-regulation during the formation of male gonadal sex in mammals has been demonstrated. The role of MAPK-signaling pathway in the human sex determination is not fully understood. Probably, MAP3K1 and the MAPK-signaling pathway are one of the genetic pathways controlling normal development of human testis. So far, several families and sporadic cases of 46,XY DSD due to mutations in MAP3K1 gene have been reported in the literature. Clinical presentation of DSD in these patients varies from female phenotype with normal externalia to male phenotype with hypospadias. We describe rare cases of the DSD 46,XY (a family case of DSD in uterine sisters and a sporadic case) with mutations in the MAP3K1 gene that haven’t been previously described. The article also presents brief literature review on this pathology.

The role of MAPK signaling pathway in the Her-2-positive meningiomas

Meningiomas are common types of adult nerve system tumors. Although most cases are considered benign, due to its high rate of recurrence and easy malignant progression to anaplastic meningioma they present a puzzle for the current treatment. The HER-2 oncogene has important value for meningioma cells development and progression. So far, little is known about the effect on the exact underlying signal pathway and molecular mechanisms of HER-2-positive meningioma cells. The goal of the present study was to determine the effects of HER-2 gene and possible involvement of MAPK signal pathway in human malignant meningioma. We applied q-PCR analysis, immunofluorescence (IF) staining, western blot analysis, animal model, MAPK inhibition, MTT assay and cell invasion analysis for the investigation. The results demonstrated that the downregulation of the expression of HER-2 significantly inhibited cell motility and proliferation of human meningioma cells in vivo. Accordingly, in the HER-2-overexpression meningioma cells with the inhibition of ERK1/2, ERK5, JNK, in the cells with the ERK1/2, ERK5 inhibition, protein expression was markedly suppressed as well as the cell proliferation resistance. No difference was observed in the HER-2-overexpression meningioma cells with the inhibition of JNK. These findings suggest that HER-2 gene can affect the proliferation ability of human meningioma cells in vivo and MAPK signal pathway may contribute to the carcinogenesis and development of human meningiomas combinating with HER-2.

Macrophage migration inhibitory factor regulating the expression of VEGF-C through MAPK signal pathways in breast cancer MCF-7 cell.

BackgroundAs a kind of versatility of cytokines, overexpression of macrophage migration inhibitory factor (MIF) and vascular endothelial growth factor-C (VEGF-C) have been reported in a wide variety of tumors. However, the correlation and mechanism between MIF and VEGF-C are still not clear. As an important signal transduction system, MAPK signaling pathways participate in a variety of biological behavior of cells. The purposes of this study are to study the relationship between MIF and VEGF-C and discuss the role of MAPK signal pathway in the relationship.MethodsIn this study, we first knocked down the MIF using small interfering RNA (siRNA) and built the stable low expression MIF breast cancer cells (siRNA-MIF-MCF-7) and the negative control cells (siRNA-NC-MCF-7). And then, we evaluated the expression of MIF using Western blot to confirm the effect of transfection. Using real-time fluorescent quantitative polymerase chain reaction and enzyme-linked immunosorbent experiment, we respectively examined the different expression of VEGF-C between siRNA-MIF-MCF-7 and siRNA-NC-MCF-7 and breast cancer cells MCF-7. Moreover, we investigated the expression of p38 MAPK, P-p38 MAPK, p44/42 MAPK, and P-p44/42 MAPK in the three kinds of cells by Western blot to analyze the regulatory mechanism to VEGF-C.ResultsWe found that MIF siRNA markedly reduced the expression of MIF. And the expression level of VEGF-C, p38 MAPK, P-p38-MAPK, p44/42-MAPK, and P-p44/42 MAPK in siRNA-MIF-MCF-7 cells had different degree of decrease compared with siRNA-NC-MCF-7 cells and MCF-7 cells.ConclusionsThese results suggest that MIF can regulate the expression of VEGF-C in breast cancer cells. And its regulatory mechanism may work by activating the MAPK signaling pathway.

Role of MAPK signaling pathways in inflammatory bowel disease

Role of MAPK signaling pathways in inflammatory bowel disease

Mitogen-activated protein kinase signaling pathways are involved in regulating α7 nicotinic acetylcholine receptor-mediated amyloid-β uptake in SH-SY5Y cells

Intraneuronal accumulation of beta-amyloid protein (Aβ) is an early pathological change in Alzheimer’s disease (AD). Recent studies demonstrate that α7 nicotinic acetylcholine receptor (α7nAChR) binds to soluble Aβ with a high affinity. In vitro and in vivo experiments also show that Aβ activates p38 MAPK and ERK1/2 signaling pathways via the α7nAChR. Interestingly, it has been reported that p38 MAPK and ERK1/2 signaling pathways affect the regulation of receptor-mediated endocytosis. These data suggest that MAPK signaling pathways maybe involved in the regulation of α7nAChR-mediated Aβ uptake. However, the evidence for this hypothesis is lacking. In the present study, we examined whether Aβ1–42 oligomers activate MAPK signaling pathways via α7nAChR, and assessed the role of MAPK signaling pathways in the regulation of Aβ1–42 uptake by α7nAChR. We confirm that undifferentiated SH-SY5Y cells are capable of taking up extracellular Aβ1–42. The internalization of Aβ1–42 accumulates in the endosomes/lysosomes and mitochondria. MAPK signaling pathways are activated by Aβ1–42 via α7nAChR. Aβ1–42 and α7nAChR are co-localized in SH-SY5Y cells and the expression of α7nAChR involves in Aβ1–42 uptake and accumulation in SH-SY5Y cells. Our data demonstrate that Aβ1–42 induces an α7nAChR-dependent pathway that relates to the activation of p38 MAPK and ERK1/2, resulting in internalization of Aβ1–42. Our findings suggest that α7nAChR and MAPK signaling pathways play an important role in the uptake and accumulation of Aβ1–42 in SH-SY5Y cells. Blockade of α7nAChR may have a beneficial effect by limiting intracellular accumulation of amyloid in AD brain and serves a potential therapeutic target for AD.

The inflammatory response of keratinocytes and its modulation by vitamin D: The role of MAPK signaling pathways

The hormonal form of vitamin D, calcitriol, and its analogs are known for their beneficial effect in the treatment of inflammatory skin disorders. Keratinocytes play a role in epidermal inflammatory responses invoked by breeching of the epidermal barrier, by infectious agents and by infiltrating immune cells. We studied the role of calcitriol in the initiation of keratinocyte inflammatory response by the viral and injury mimic polyinosinic-polycytidylic acid (poly(I:C)) and in its maintenance by tumor-necrosis-factor α (TNFα) and investigated the role of the mitogen-activated protein kinase cascades in these processes and their regulation by calcitriol. The inflammatory response of human HaCaT keratinocytes to poly(I:C) or TNFα was assessed by measuring mRNA levels of 13 inflammation-related molecules by real-time PCR microarray and by in-depth investigation of the regulation of interleukin 8, intercellular-adhesion-molecule 1, and TNFα expression. We found that while calcitriol had only a minor effect on the keratinocyte response to poly(I:C) and a modest effect on the early response (2 h) to TNFα, it markedly attenuated the later response (16-24 h) to TNFα. The expression of CYP27B1, the enzyme responsible for calcitriol production, was marginally increased by poly(I:C) and markedly by TNFα treatment. This pattern suggests that while allowing the initial keratinocyte inflammatory response to proceed, calcitriol contributes to its timely resolution. Using pharmacological inhibitors we found that while the p38 MAPK and the extracellular signal-regulated kinase have only a minor role, c-Jun N-terminal kinase plays a pivotal role in the induction of the pro-inflammatory genes and its modulation by calcitriol.

The regulation of BLyS expression levels through MAPK signal pathway in multiple myeloma

Objective To investigate the activation of MAPK signal pathway in multiple myeloma and the regulation of BLyS expression levels through MAPK signal pathway; preliminarily study the role of MAPK signal pathway in the up-regulation of BLyS expression levels induced by IFN-γ.Methods Activated MAPK pathway were detected by Western blot,while the expression of BLyS were detected with RT-PCR and Western blot,and Western blot investigated the effect of MAPK pathway on BLyS expression levels induced by IFN-γ.Results In addition to the expression of ERK,JNK,p38,p-JNK was also expressed in MM cell lines,the MAPK pathway inhibitor targeting JNK SP600125 can down-regulate the expression of BLyS,and its activator anisomycin can up-regulate the expression of BLyS.SP600125 restrained the proliferation and survival of MM cells.Conclusion JNK/SAPK pathway was activated in MM cells; The activated degree of JNK/SAPK pathway and the expression level of BLyS was positively correlated.JNK/SAPK pathway play an important role in the up-regulation of BLyS expression levels induced by IFN-γ. Key words: Multiple myeloma; B-lymphocyte stimulator (BLyS) ; MAPK signal pathway

NHE1 mediates MDA-MB-231 cells invasion through the regulation of MT1-MMP

Na +/H + exchanger 1 (NHE1), an important regulator of intracellular pH (pH i) and extracellular pH (pH e), has been shown to play a key role in breast cancer metastasis. However, the exact mechanism by which NHE1 mediates breast cancer metastasis is not yet well known. We showed here that inhibition of NHE1 activity, with specific inhibitor Cariporide, could suppress MDA-MB-231 cells invasion as well as the activity and expression of MT1-MMP. Overexpression of MT1-MMP resulted in a distinguished increase in MDA-MB-231 cells invasiveness, but treatment with Cariporide reversed the MT1-MMP-mediated enhanced invasiveness. To explore the role of MAPK signaling pathways in NHE1-mediated breast cancer metastasis, we compared the difference of constitutively phosphorylated ERK1/2, p38 MAPK and JNK in non-invasive MCF-7 cells and invasive MDA-MB-231cells. Interestingly, we found that the phosphorylation levels of ERK1/2 and p38 MAPK in MDA-MB-231 cells were higher than in MCF-7 cells, but both MCF-7 cells and MDA-MB-231 cells expressed similar constitutively phosphorylated JNK. Treating MDA-MB-231 cells with Cariporide led to decreased phosphorylation level of both p38 MAPK and ERK1/2 in a time-dependent manner, but JNK activity was not influenced. Supplementation with MAPK inhibitor (MEK inhibitor PD98059, p38 MAPK inhibitor SB203580 and JNK inhibitor SP600125) or Cariporide all exhibited significant depression of MDA-MB-231 cells invasion and MT1-MMP expression. Furthermore, we co-treated MDA-MB-231 cells with MAPK inhibitor and Cariporide. The result showed that Cariporide synergistically suppressed invasion and MT1-MMP expression with MEK inhibitor and p38 MAPK inhibitor, but not be synergistic with the JNK inhibitor. These findings suggest that NHE1 mediates MDA-MB-231 cells invasion partly through regulating MT1-MMP in ERK1/2 and p38 MAPK signaling pathways dependent manner.

Role of MAPK signal pathway in the regulation of IL-23p19 expression in human microglia (129.29)

Abstract Activated microglia can release a variety of proinflammatory cytokines that play a crucial role in the pathogenesis of multiple sclerosis (MS). IL-23 is a novel proinflammatory cytokine that shares the p40 subunit with IL-12 and is required for the induction of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. However, IL-23 expression and regulation in human microglia is poorly understood. Here we detected IL-23p19 mRNA expression on human microglia by northern blot and protein level by double-fluorescence immunostaining analysis. When the intracellular signaling pathway for p19 regulation was determined, we found that IL-23p19 expression in human microglia was significantly reduced by blocking the p38 MAP kinase pathway with either neutralizing antibodies or dominant-negative p38 transduction. Thus, human microglia inducibly express p19, and the p38 MAP kinase signaling pathway plays a major role in regulation of p19 expression.

Involvement of p38-mitogen-activated protein kinase in adenosine receptor-mediated relaxation of coronary artery

The purpose of this study was to explore the involvement of adenosine receptor(s) in porcine coronary artery (PCA) relaxation and to define the role of MAPK signaling pathways. Isometric tensions were recorded in denuded PCA rings. 5'-(N-ethylcarboxamido)adenosine (NECA), a nonselective adenosine receptor agonist, induced a concentration-dependent relaxation (EC(50) = 16.8 nM) of PGF(2alpha) (10 microM)-preconstricted arterial rings. NECA-induced relaxation was completely blocked by 0.1 microM SCH-58261 (A(2A) antagonist) at lower doses (1-40 nM) but not at higher doses (80-1,000 nM). MRS-1706 (1 microM, A(2B) antagonist) was able to shift the NECA concentration-response curve to the right. CGS-21680 (selective A(2A) agonist) induced responses similarly to NECA, whereas N(6)-cyclopentyladenosine (A(1) agonist) and Cl-IB-MECA (A(3) agonist) did not. Furthermore, the effect of NECA was attenuated by the addition of SB-203580 (10 microM, p38 MAPK inhibitor) but not by PD-98059 (10 microM, MEK inhibitor). Interestingly, SB-203580 had no effect on CGS-21680-induced relaxation. Western blot analysis demonstrated that PGF(2alpha) and adenosine agonists stimulated p38 MAPK at a concentration of 40 nM in PCA smooth muscle cells. MRS-1706 (1 microM) significantly reduced NECA-induced p38 MAPK phosphorylation. Addition of NECA and SB-203580 alone or in combination inhibited PGF(2alpha)-induced p38 MAPK. Western blot data were further confirmed by p38 MAPK activity measurement using activating transcription factor-2 assay. Our results suggest that the adenosine receptor subtype involved in causing relaxation of porcine coronary smooth muscle is mainly A(2A) subtype, although A(2B) also may play a role, possibly through p38 MAPK pathway.