A molluscan extracellular signal-regulated kinase is involved in host response to immune challenges in vivo and in vitro

2017 ◽  
Vol 62 ◽  
pp. 311-319 ◽  
Author(s):  
Fufa Qu ◽  
Zhiming Xiang ◽  
Jun Li ◽  
Shu Xiao ◽  
Fan Mao ◽  
...  
Keyword(s):  
Host Response ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Immune Challenges

scholarly journals Critical role of the extracellular signal–regulated kinase–MAPK pathway in osteoblast differentiation and skeletal development

2007 ◽  
Vol 176 (5) ◽  
pp. 709-718 ◽  
Author(s):  
Chunxi Ge ◽  
Guozhi Xiao ◽  
Di Jiang ◽  
Renny T. Franceschi
Keyword(s):  
Transcriptional Activity ◽  
Mapk Pathway ◽  
Skeletal Development ◽  
Critical Role ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal

The extracellular signal–regulated kinase (ERK)–mitogen-activated protein kinase (MAPK) pathway provides a major link between the cell surface and nucleus to control proliferation and differentiation. However, its in vivo role in skeletal development is unknown. A transgenic approach was used to establish a role for this pathway in bone. MAPK stimulation achieved by selective expression of constitutively active MAPK/ERK1 (MEK-SP) in osteoblasts accelerated in vitro differentiation of calvarial cells, as well as in vivo bone development, whereas dominant-negative MEK1 was inhibitory. The involvement of the RUNX2 transcription factor in this response was established in two ways: (a) RUNX2 phosphorylation and transcriptional activity were elevated in calvarial osteoblasts from TgMek-sp mice and reduced in cells from TgMek-dn mice, and (b) crossing TgMek-sp mice with Runx2+/− animals partially rescued the hypomorphic clavicles and undemineralized calvaria associated with Runx2 haploinsufficiency, whereas TgMek-dn; Runx2+/− mice had a more severe skeletal phenotype. This work establishes an important in vivo function for the ERK–MAPK pathway in bone that involves stimulation of RUNX2 phosphorylation and transcriptional activity.

scholarly journals Synergistic Autophagy Effect of miR-212-3p in Zoledronic Acid-Treated In Vitro and Orthotopic In Vivo Models and in Patient-Derived Osteosarcoma Cells

Cancers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1812 ◽  
Author(s):  
Ju Oh ◽  
Eun Kim ◽  
Yeon-Joo Lee ◽  
Sei Sai ◽  
Sun Lim ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Zoledronic Acid ◽  
Mammalian Target Of Rapamycin ◽  
In Vivo Models ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Kinase Pathway ◽  
Autophagy Inhibition

Osteosarcoma (OS) originates from osteoid bone tissues and is prone to metastasis, resulting in a high mortality rate. Although several treatments are available for OS, an effective cure does not exist for most patients with advanced OS. Zoledronic acid (ZOL) is a third-generation bisphosphonate that inhibits osteoclast-mediated bone resorption and has shown efficacy in treating bone metastases in patients with various types of solid tumors. Here, we sought to clarify the mechanisms through which ZOL inhibits OS cell proliferation. ZOL treatment inhibited OS cell proliferation, viability, and colony formation. Autophagy inhibition by RNA interference against Beclin-1 or ATG5 inhibited ZOL-induced OS cell death. ZOL induced autophagy by repressing the protein kinase B/mammalian target of rapamycin/p70S6 kinase pathway and extracellular signal-regulated kinase signaling-dependent autophagy in OS cell lines and patient-derived OS cells. Microarrays of miRNA showed that ZOL increased the levels of miR-212-3p, which is known to play an important role in autophagy, in OS in vitro and in vivo systems. Collectively, our data provided mechanistic insight into how increased miR-212-3p through ZOL treatment induces autophagy synergistically in OS cells, providing a preclinical rationale for conducting a broad-scale clinical evaluation of ZOL + miR-212-3p in treating OS.

scholarly journals Extracellular Signal-Regulated Kinase 1 Interacts with and Phosphorylates CdGAP at an Important Regulatory Site

2005 ◽  
Vol 25 (15) ◽  
pp. 6314-6329 ◽  
Author(s):  
Joseph Tcherkezian ◽  
Eric I. Danek ◽  
Sarah Jenna ◽  
Ibtissem Triki ◽  
Nathalie Lamarche-Vane
Keyword(s):  
Bound States ◽  
Mitogen Activated Protein Kinase ◽  
Regulatory Site ◽  
Nucleotide Exchange ◽  
Rich Region ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Proline Rich Region

ABSTRACT Rho GTPases regulate multiple cellular processes affecting both cell proliferation and cytoskeletal dynamics. Their cycling between inactive GDP- and active GTP-bound states is tightly regulated by guanine nucleotide exchange factors and GTPase-activating proteins (GAPs). We have previously identified CdGAP (for Cdc42 GTPase-activating protein) as a specific GAP for Rac1 and Cdc42. CdGAP consists of an N-terminal RhoGAP domain and a C-terminal proline-rich region. In addition, CdGAP is a member of the impressively large number of mammalian RhoGAP proteins that is well conserved among both vertebrates and invertebrates. In mice, we find two predominant isoforms of CdGAP differentially expressed in specific tissues. We report here that CdGAP is highly phosphorylated in vivo on serine and threonine residues. We find that CdGAP is phosphorylated downstream of the MEK-extracellular signal-regulated kinase (ERK) pathway in response to serum or platelet-derived growth factor stimulation. Furthermore, CdGAP interacts with and is phosphorylated by ERK-1 and RSK-1 in vitro. A putative DEF (docking for ERK FXFP) domain located in the proline-rich region of CdGAP is required for efficient binding and phosphorylation by ERK1/2. We identify Thr776 as an in vivo target site of ERK1/2 and as an important regulatory site of CdGAP activity. Together, these data suggest that CdGAP is a novel substrate of ERK1/2 and mediates cross talk between the Ras/mitogen-activated protein kinase pathway and regulation of Rac1 activity.

scholarly journals Splicing factor hnRNPA2B1 contributes to tumorigenic potential of breast cancer cells through STAT3 and ERK1/2 signaling pathway

Tumor Biology ◽  
2017 ◽  
Vol 39 (3) ◽  
pp. 101042831769431 ◽  
Author(s):  
Ying Hu ◽  
Zihan Sun ◽  
Jinmu Deng ◽  
Baoquan Hu ◽  
Wenting Yan ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Signal Transducer ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Tumorigenic Potential ◽  
Transcription 3

Increasing evidence has indicated that the splicing factor hnRNPA2B1 plays a direct role in cancer development, progression, gene expression, and signal transduction. Previous studies have shown that knocking down hnRNPA2B1 in breast cancer cells induces apoptosis, but the mechanism and other functions of hnRNPA2B1 in breast cancer are unknown. The goal of this study was to investigate the biological function, clinical significance, and mechanism of hnRNPA2B1 in breast cancer. The expression of hnRNPA2B1 in 92 breast cancer and adjacent normal tissue pairs was analyzed by immunohistochemical staining. Stable clones exhibiting knockdown of hnRNPA2B1 via small hairpin RNA expression were generated using RNA interference technology in breast cancer cell lines. The effects of hnRNPA2B1 on cell proliferation were examined by MTT and EdU assay, and cellular apoptosis and the cell cycle were examined by flow cytometry. A nude mouse xenograft model was established to elucidate the function of hnRNPA2B1 in tumorigenesis in vivo. The role of hnRNPA2B1 in signaling pathways was investigated in vitro. Our data revealed that hnRNPA2B1 was overexpressed in breast cancer tissue specimens and cell lines. Knockdown of hnRNPA2B1 reduced breast cancer cell proliferation, induced apoptosis, and prolonged the S phase of the cell cycle in vitro. In addition, hnRNPA2B1 knockdown suppressed subcutaneous tumorigenicity in vivo. On a molecular level, hnRNPA2B1 knockdown decreased signal transducer and activator of transcription 3 and extracellular-signal-regulated kinase 1/2 phosphorylation. We concluded that hnRNPA2B1 promotes the tumorigenic potential of breast cancer cells, MCF-7 and MDA-MB-231, through the extracellular-signal-regulated kinase 1/2 or signal transducer and activator of transcription 3 pathway, which may serve as a target for future therapies.

Glycyrrhizic Acid Modulates Apoptosis through Extrinsic/Intrinsic Pathways and Inhibits Protein Kinase B- and Extracellular Signal-Regulated Kinase-Mediated Metastatic Potential in Hepatocellular Carcinoma In Vitro and In Vivo

2020 ◽  
Vol 48 (01) ◽  
pp. 223-244
Author(s):  
Jai-Jen Tsai ◽  
Po-Jung Pan ◽  
Fei-Ting Hsu ◽  
Jing-Gung Chung ◽  
I-Tsang Chiang
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Invasion ◽  
Glycyrrhizic Acid ◽  
Metastatic Potential ◽  
Signaling Transduction ◽  
Apoptotic Signaling ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal

A previous study presented that glycyrrhizic acid as the hepatoprotective agent inhibits total parenteral nutrition-associated acute liver injury in rats. However, the anticancer effect and mechanism of glycyrrhizic acid in human hepatocellular carcinoma (HCC) is ambiguous. The purpose of the present study was to investigate the effect of glycyrrhizic acid on apoptosis dysregulation and metastatic potential in HCC in vitro and in vivo. Both SK-Hep1 and Hep3B cells were treated with different concentrations of glycyrrhizic acid for 24 or 48[Formula: see text]h. SK-Hep1/luc2 tumor-bearing mice were treated with vehicle or glycyrrhizic acid (50[Formula: see text]mg/kg/day by intraperitoneal injection) for 7 days. Tumor cells growth, apoptotic, and metastatic signaling transduction were evaluated by using MTT assay, digital caliper, bioluminescence imaging (BLI), flow cytometry, western blotting assay, and immunohistochemistry (IHC) staining. The results demonstrated glycyrrhizic acid significantly inhibits tumor cell growth, cell invasion, and expression of AKT (Ser473), extracellular-signal-regulated kinase (ERK), epidermal growth factor receptor (EGFR) phosphorylation, anti-apoptotic and metastatic proteins in HCC in vitro and in vivo. Glycyrrhizic acid also significantly triggered apoptosis and extrinsic/intrinsic apoptotic signaling transduction. In addition, PD98059 (ERK inhibitor) and LY294002 (AKT inhibitor) obviously reduced cell invasion and expression of metastasis-associated proteins. Taken together, these results indicated that glycyrrhizic acid induces apoptosis through extrinsic/intrinsic apoptotic signaling pathways and diminishes EGFR/AKT/ERK-modulated metastatic potential in HCC in vitro and in vivo.

scholarly journals Inhibitory Effect of Arctigenin from Fructus Arctii Extract on Melanin Synthesis via Repression of Tyrosinase Expression

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Hwayong Park ◽  
Kwang Hoon Song ◽  
Pil Mun Jung ◽  
Ji-Eun Kim ◽  
Hyunju Ro ◽  
...  
Keyword(s):  
Active Compound ◽  
Gene Promoter ◽  
Inhibitory Effect ◽  
Tyrosinase Activity ◽  
Dependent Manner ◽  
Melanin Content ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal

To identify the active compound arctigenin in Fructus Arctii (dried seed of medicinal plantArctium lappa) and to elucidate the inhibitory mechanism in melanogenesis, we analyzed melanin content and tyrosinase activity on B16BL6 murine melanoma and melan-A cell cultures. Water extracts of Fructus Arctii were shown to inhibit tyrosinase activity in vitro and melanin content inα-melanocyte stimulating hormone-stimulated cells to similar levels as the well-known kojic acid and arbutin, respectively. The active compound arctigenin of Fructus Arctii displayed little or no cytotoxicity at all concentrations examined and decreased the relative melanin content and tyrosinase activity in a dose-dependent manner. Melanogenic inhibitory activity was also identified in vivo with zebrafish embryo. To determine the mechanism of inhibition, the effects of arctigenin on tyrosinase gene expression and tyrosinase promoter activity were examined. Also in addition, in the signaling cascade, arctigenin dose dependently decreased the cAMP level and promoted the phosphorylation of extracellular signal-regulated kinase. This result suggests that arctigenin downregulates cAMP and the tyrosinase enzyme through its gene promoter and subsequently upregulates extracellular signal-regulated kinase activity by increasing phosphorylation in the melanogenesis signaling pathway, which leads to a lower melanin content.

scholarly journals Neogenin Regulates Skeletal Myofiber Size and Focal Adhesion Kinase and Extracellular Signal-regulated Kinase Activities In Vivo and In Vitro

2009 ◽  
Vol 20 (23) ◽  
pp. 4920-4931 ◽  
Author(s):  
Gyu-Un Bae ◽  
Youn-Joo Yang ◽  
Guoying Jiang ◽  
Mingi Hong ◽  
Hye-Jin Lee ◽  
...  
Keyword(s):  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Myogenic Differentiation ◽  
Dependent Manner ◽  
Extracellular Signal Regulated Kinase ◽  
Myotube Formation ◽  
Extracellular Signal ◽  
Repulsive Guidance Molecule

A variety of signaling pathways participate in the development of skeletal muscle, but the extracellular cues that regulate such pathways in myofiber formation are not well understood. Neogenin is a receptor for ligands of the netrin and repulsive guidance molecule (RGM) families involved in axon guidance. We reported previously that neogenin promoted myotube formation by C2C12 myoblasts in vitro and that the related protein Cdo (also Cdon) was a potential neogenin coreceptor in myoblasts. We report here that mice homozygous for a gene-trap mutation in the Neo1 locus (encoding neogenin) develop myotomes normally but have small myofibers at embryonic day 18.5 and at 3 wk of age. Similarly, cultured myoblasts derived from such animals form smaller myotubes with fewer nuclei than myoblasts from control animals. These in vivo and in vitro defects are associated with low levels of the activated forms of focal adhesion kinase (FAK) and extracellular signal-regulated kinase (ERK), both known to be involved in myotube formation, and inefficient expression of certain muscle-specific proteins. Recombinant netrin-2 activates FAK and ERK in cultured myoblasts in a neogenin- and Cdo-dependent manner, whereas recombinant RGMc displays lesser ability to activate these kinases. Together, netrin-neogenin signaling is an important extracellular cue in regulation of myogenic differentiation and myofiber size.

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