scholarly journals Baicalein Inhibits MMPs Expression via a MAPK-Dependent Mechanism in Chondrocytes

2015 ◽  
Vol 36 (1) ◽  
pp. 325-333 ◽  
Author(s):  
Wei-Ping Chen ◽  
Yan Xiong ◽  
Peng-Fei Hu ◽  
Jia-Peng Bao ◽  
Li-Dong Wu
Keyword(s):  
Cruciate Ligament ◽  
Interleukin 1 ◽  
Cartilage Damage ◽  
Rabbit Model ◽  
Mitogen Activated Protein Kinase ◽  
Scutellaria Baicalensis Georgi ◽  
The Matrix ◽  
Mitogen Activated Protein

Background: Baicalein is a flavonoid isolated from Scutellaria baicalensis Georgi. Here, we investigated the anti-osteoarthritic effect of baicalein in vitro and in vivo. Methods: Interleukin-1 beta (IL-1β)-induced chondrocytes were treated with different concentrations of baicalein, real-time PCR and ELISA were performed to detect the matrix metalloproteinases (MMPs) expression. Western blot was used to evaluate the mitogen-activated protein kinase (MAPK) expression. In experimental osteoarthritis (OA), rabbits were treated with baicalein, gross morphological and histological assessment was performed to evaluate the cartilage damage. Results: Baicalein significantly reduced the expression of MMPs in vitro and in vivo. Moreover, baicalein significantly reduced the phosphorylation of p38 and extracellular signal regulated kinase (ERK), but not of c-Jun N-terminal kinase (JNK). In addition, intra-articular injection of baicalein ameliorated the cartilage damage in a rabbit model of OA induced by anterior cruciate ligament transection (ACLT). Conclusions: The results indicate that baicalein may be considered as a potential agent for OA treatment.

scholarly journals A Novel Synthesized Sulfonamido-Based Gallate-JEZTC Blocks Cartilage Degradation on Rabbit Model of Osteoarthritis: An in Vitro and in Vivo Study

2018 ◽  
Vol 49 (6) ◽  
pp. 2304-2319 ◽  
Author(s):  
Zhenhui Lu ◽  
Qin Liu ◽  
Lei Liu ◽  
Huayu Wu ◽  
Li Zheng ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Cruciate Ligament ◽  
Interleukin 1 ◽  
Rabbit Model ◽  
Cartilage Degradation ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Histological Evaluation ◽  
Chondrocyte Apoptosis

Background/Aims: 3, 4, 5-trihydroxy-N-{4-[(5-methylisoxazol-3-yl) sulfamoyl] phenyl} benzamide (JEZTC), synthesized from gallic acid (GA) and sulfamethoxazole (SMZ), was reported with chondroprotective effects. However, the effects of JEZTC on osteoarthritis (OA) are still unclear. The goal of this study was to investigate the anti-osteoarthritic properties of JEZTC on interleukin-1-beta (IL-1β) stimulated chondrocytes in vitro and a rabbit anterior cruciate ligament transaction (ACLT) OA model in vivo. Methods: Changes in matrix metalloproteinases (MMPs) and apoptosis genes (bax, caspase 3 and tnf-α) and OA-specific protein (MMP-1) expression in vitro and in vivo were detected by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemistry. The production of reactive oxygen species (ROS) were investigated upon the treatment of JEZTC in chondrocytes processed with IL-1β in vitro and OA in vivo. Effect of JEZTC on OA was further studied by the macroscopic and histological evaluation and scores. The key proteins in signaling pathways inMAPK/P38, PI3KAkt and NF-κB also determined using western blot (WB) analysis. Results: JEZTC could significantly suppress the expression of MMPs and intracellular ROS, while meaningfully increase the gene expression of tissue inhibitor of metalloproteinase-1 (TIMP-1). Moreover, there was less cartilage degradation in JEZTC group compared with the phosphate-buffered saline (PBS) group in vivo. Results also indicated that JEZTC exerts effect on OA by regulating MAPKs and PI3K/Akt signaling pathways to activate NF-κB pathway, leading to the down-regulation of MMPs. The chondro-protective effect of JEZTC may be related with its ability to inhibit chondrocyte apoptosis by reduction of ROS production. Conclusion: JEZTC may be a possible therapeutic agent in the treatment of OA.

Morin exerts antiosteoarthritic properties: an in vitro and in vivo study

2012 ◽  
Vol 237 (4) ◽  
pp. 380-386 ◽  
Author(s):  
Wei-Ping Chen ◽  
Peng-Fei Hu ◽  
Jia-Peng Bao ◽  
Li-Dong Wu
Keyword(s):  
Rat Model ◽  
Cruciate Ligament ◽  
Interleukin 1 ◽  
Cartilage Degradation ◽  
In Vivo Study ◽  
In Vivo Studies ◽  
Tissue Inhibitors Of Metalloproteinase ◽  
Mitogen Activated Protein

Morin is a flavonoid isolated from members of the Moraceae family. Morin has been reported to possess antioxidative and anticarcinogenic activities. However, the antiosteoarthritic properties of morin have not been investigated. In this study, we evaluate the antiarthritic properties of morin through in vitro and in vivo studies. We examined the effects of morin on the expression levels of matrix metalloproteinase (MMP)-3, MMP-13 and tissue inhibitors of metalloproteinase (TIMP)-1 in interleukin-1 β (IL-1 β)-induced rat chondrocytes by realtime polymerase chain reaction and Western blotting. The effects of morin on the phosphorylation of mitogen-activated protein kinases were also investigated. The in vivo antiosteoarthritic effects of morin were evaluated in the rat model of anterior cruciate ligament transection (ACLT)-induced osteoarthritis (OA). We found that morin inhibited the expression of MMP-3 and MMP-13 and increased the expression of TIMP-1 in IL-1 β-induced rat chondrocytes. In addition, morin inhibited IL-1 β-induced phosphorylation of extracellular signal-regulated kinase and p38. For the in vivo study in a rat model of OA induced by ACLT, in which morin was orally administered to rat, the results show that morin suppressed cartilage degradation. Our results suggest that morin may be considered as a possible therapeutic agent for the treatment of OA.

scholarly journals Cross-talk between IRAK-4 and the NADPH oxidase1

2007 ◽  
Vol 403 (3) ◽  
pp. 451-461 ◽  
Author(s):  
Sandrine Pacquelet ◽  
Jennifer L. Johnson ◽  
Beverly A. Ellis ◽  
Agnieszka A. Brzezinska ◽  
William S. Lane ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Nadph Oxidase ◽  
P38 Mapk ◽  
Interleukin 1 ◽  
Mitogen Activated Protein Kinase ◽  
Free System ◽  
Mitogen Activated Protein ◽  
A Cell ◽  
Tlr4 Activation

Exposure of neutrophils to LPS (lipopolysaccharide) triggers their oxidative response. However, the relationship between the signalling downstream of TLR4 (Toll-like receptor 4) after LPS stimulation and the activation of the oxidase remains elusive. Phosphorylation of the cytosolic factor p47phox is essential for activation of the NADPH oxidase. In the present study, we examined the hypothesis that IRAK-4 (interleukin-1 receptor-associated kinase-4), the main regulatory kinase downstream of TLR4 activation, regulates the NADPH oxidase through phosphorylation of p47phox. We show that p47phox is a substrate for IRAK-4. Unlike PKC (protein kinase C), IRAK-4 phosphorylates p47phox not only at serine residues, but also at threonine residues. Target residues were identified by tandem MS, revealing a novel threonine-rich regulatory domain. We also show that p47phox is phosphorylated in granulocytes in response to LPS stimulation. LPS-dependent phosphorylation of p47phox was enhanced by the inhibition of p38 MAPK (mitogen-activated protein kinase), confirming that the kinase operates upstream of p38 MAPK. IRAK-4-phosphorylated p47phox activated the NADPH oxidase in a cell-free system, and IRAK-4 overexpression increased NADPH oxidase activity in response to LPS. We have shown that endogenous IRAK-4 interacts with p47phox and they co-localize at the plasma membrane after LPS stimulation, using immunoprecipitation assays and immunofluorescence microscopy respectively. IRAK-4 was activated in neutrophils in response to LPS stimulation. We found that Thr133, Ser288 and Thr356, targets for IRAK-4 phosphorylation in vitro, are also phosphorylated in endogenous p47phox after LPS stimulation. We conclude that IRAK-4 phosphorylates p47phox and regulates NADPH oxidase activation after LPS stimulation.

scholarly journals Role for the Ran Binding Protein, Mog1p, in Saccharomyces cerevisiae SLN1-SKN7 Signal Transduction

2004 ◽  
Vol 3 (6) ◽  
pp. 1544-1556 ◽  
Author(s):  
Jade Mei-Yeh Lu ◽  
Robert J. Deschenes ◽  
Jan S. Fassler
Keyword(s):  
Signal Transduction ◽  
Transcription Factor ◽  
Osmotic Stress ◽  
Kinase Activity ◽  
Mitogen Activated Protein Kinase ◽  
Osmotic Response ◽  
Mitogen Activated Protein ◽  
Kinase Pathway

ABSTRACT Yeast Sln1p is an osmotic stress sensor with histidine kinase activity. Modulation of Sln1 kinase activity in response to changes in the osmotic environment regulates the activity of the osmotic response mitogen-activated protein kinase pathway and the activity of the Skn7p transcription factor, both important for adaptation to changing osmotic stress conditions. Many aspects of Sln1 function, such as how kinase activity is regulated to allow a rapid response to the continually changing osmotic environment, are not understood. To gain insight into Sln1p function, we conducted a two-hybrid screen to identify interactors. Mog1p, a protein that interacts with the yeast Ran1 homolog, Gsp1p, was identified in this screen. The interaction with Mog1p was characterized in vitro, and its importance was assessed in vivo. mog1 mutants exhibit defects in SLN1-SKN7 signal transduction and mislocalization of the Skn7p transcription factor. The requirement for Mog1p in normal localization of Skn7p to the nucleus does not fully account for the mog1-related defects in SLN1-SKN7 signal transduction, raising the possibility that Mog1p may play a role in Skn7 binding and activation of osmotic response genes.

scholarly journals Extracellular Signal-Regulated Kinases Phosphorylate Mitogen-Activated Protein Kinase Phosphatase 3/DUSP6 at Serines 159 and 197, Two Sites Critical for Its Proteasomal Degradation

2005 ◽  
Vol 25 (2) ◽  
pp. 854-864 ◽  
Author(s):  
Sandrine Marchetti ◽  
Clotilde Gimond ◽  
Jean-Claude Chambard ◽  
Thomas Touboul ◽  
Danièle Roux ◽  
...  
Keyword(s):  
Map Kinases ◽  
Fluorescent Protein ◽  
Proteasomal Degradation ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Double Mutation ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT Mitogen-activated protein (MAP) kinase phosphatases (MKPs) are dual-specificity phosphatases that dephosphorylate phosphothreonine and phosphotyrosine residues within MAP kinases. Here, we describe a novel posttranslational mechanism for regulating MKP-3/Pyst1/DUSP6, a member of the MKP family that is highly specific for extracellular signal-regulated kinase 1 and 2 (ERK1/2) inactivation. Using a fibroblast model in which the expression of either MKP-3 or a more stable MKP-3-green fluorescent protein (GFP) chimera was induced by tetracycline, we found that serum induces the phosphorylation of MKP-3 and its subsequent degradation by the proteasome in a MEK1 and MEK2 (MEK1/2)-ERK1/2-dependent manner. In vitro phosphorylation assays using glutathione S-transferase (GST)-MKP-3 fusion proteins indicated that ERK2 could phosphorylate MKP-3 on serines 159 and 197. Tetracycline-inducible cell clones expressing either single or double serine mutants of MKP-3 or MKP-3-GFP confirmed that these two sites are targeted by the MEK1/2-ERK1/2 module in vivo. Double serine mutants of MKP-3 or MKP-3-GFP were more efficiently protected from degradation than single mutants or wild-type MKP-3, indicating that phosphorylation of either serine by ERK1/2 enhances proteasomal degradation of MKP-3. Hence, double mutation caused a threefold increase in the half-life of MKP-3. Finally, we show that the phosphorylation of MKP-3 has no effect on its catalytic activity. Thus, ERK1/2 exert a positive feedback loop on their own activity by promoting the degradation of MKP-3, one of their major inactivators in the cytosol, a situation opposite to that described for the nuclear phosphatase MKP-1.

Adrenomedullin: angiogenesis and gene therapy

2005 ◽  
Vol 288 (6) ◽  
pp. R1432-R1437 ◽  
Author(s):  
Noritoshi Nagaya ◽  
Hidezo Mori ◽  
Shinsuke Murakami ◽  
Kenji Kangawa ◽  
Soichiro Kitamura
Keyword(s):  
Gene Transfer ◽  
Cell Biology ◽  
Therapeutic Potential ◽  
Lattice Structure ◽  
Rabbit Model ◽  
Mitogen Activated Protein Kinase ◽  
Tissue Ischemia ◽  
Hypoxic Conditions

Adrenomedullin (AM) is a potent, long-lasting vasodilator peptide that was originally isolated from human pheochromocytoma. AM signaling is of particular significance in endothelial cell biology since the peptide protects cells from apoptosis, promotes angiogenesis, and affects vascular tone and permeability. The angiogenic effect of AM is mediated by activation of Akt, mitogen-activated protein kinase/extracellular signal-regulated kinase 1/2, and focal adhesion kinase in endothelial cells. Both AM and its receptor, calcitonin receptor-like receptor, are upregulated through a hypoxia-inducible factor-1-dependent pathway under hypoxic conditions. Thus AM signaling plays an important role in the regulation of angiogenesis in hypoxic conditions. Recently, we have developed a nonviral vector, gelatin. Positively charged gelatin holds negatively charged plasmid DNA in its lattice structure. DNA-gelatin complexes can delay gene degradation, leading to efficient gene transfer. Administration of AM DNA-gelatin complexes induces potent angiogenic effects in a rabbit model of hindlimb ischemia. Thus gelatin-mediated AM gene transfer may be a new therapeutic strategy for the treatment of tissue ischemia. Endothelial progenitor cells (EPCs) play an important role in endothelial regeneration. Interestingly, EPCs phagocytose ionically linked DNA-gelatin complexes in coculture, which allows nonviral gene transfer into EPCs. AM gene transfer into EPCs inhibits cell apoptosis and induces proliferation and migration, suggesting that AM gene transfer strengthens the therapeutic potential of EPCs. Intravenous administration of AM gene-modified EPCs regenerate pulmonary endothelium, resulting in improvement of pulmonary hypertension. These results suggest that in vivo and in vitro transfer of AM gene using gelatin may be applicable for intractable cardiovascular disease.

Amentoflavone Inhibits Osteoclastogenesis and Wear Debris-Induced Osteolysis via Suppressing NF-κB and MAPKs Signaling Pathways

Planta Medica ◽  
2018 ◽  
Vol 84 (11) ◽  
pp. 759-767 ◽  
Author(s):  
Zhen Zhang ◽  
Shuai Zhao ◽  
Xiaolei Li ◽  
Xiaoqi Zhuo ◽  
Wu Zhang ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Aseptic Loosening ◽  
Wear Debris ◽  
Mitogen Activated Protein Kinase ◽  
Micro Computed Tomography ◽  
Computed Tomography Scanning ◽  
Mitogen Activated Protein ◽  
And Function

AbstractWear debris-induced osteolysis is one of the major reasons for subsequent aseptic loosening after cementless hip arthroplasty. Increasing evidence suggests that receptor activator of nuclear factor kappa-B (NF-κB) ligand-mediated osteoclastogenesis and osteolysis are responsible for wear debris-induced aseptic loosening. In the present study, we explored the effect of amentoflavone (AMF) on inhibiting osteoclast generation and wear debris-induced osteolysis in vitro and in vivo. Twenty-four male C57BL/J6 mice were randomly divided into four groups: a sham group and groups with titanium wear debris treatment followed by intraperitoneal injection of various concentrations of AMF (0, 20, and 40 mg/kg/day). The micro computed tomography scanning and histological analysis were performed. Bone marrow-derived macrophages were cultured to investigate the effect of AMF on osteoclast generation and function. The results showed that AMF suppressed osteoclastogenesis, F-actin ring formation, and bone absorption without cytotoxicity. AMF prevented titanium wear debris-induced osteolysis in mice. AMF suppressed the relative proteins of NF-κB and mitogen-activated protein kinase (MAPKs) signaling pathways. Thus, the present study suggests that AMF derived from plants could inhibit osteoclastogenesis and titanium wear debris-induced osteolysis via suppressing NF-κB and MAPKs signaling pathways.

scholarly journals FGIN-1-27 Inhibits Melanogenesis by Regulating Protein Kinase A/cAMP-Responsive Element-Binding, Protein Kinase C-β, and Mitogen-Activated Protein Kinase Pathways

2020 ◽  
Vol 11 ◽  
Author(s):  
Jinpeng Lv ◽  
Songzhou Jiang ◽  
Ying Yang ◽  
Ximei Zhang ◽  
Rongyin Gao ◽  
...  
Keyword(s):  
Protein Kinase ◽  
The Body ◽  
Tyrosinase Activity ◽  
Mitogen Activated Protein Kinase ◽  
Mushroom Tyrosinase ◽  
Mitogen Activated Protein ◽  
Element Binding Protein ◽  
Responsive Element

FGIN-1-27 is a synthetic mitochondrial diazepam binding inhibitor receptor (MDR) agonist that has demonstrated pro-apoptotic, anti-anxiety, and steroidogenic activity in various studies. Here we report, for the first time, the anti-melanogenic efficacy of FGIN-1-27 in vitro and in vivo. FGIN-1-27 significantly inhibited basal and α-melanocyte-stimulating hormone (α-MSH)-, 1-Oleoyl-2-acetyl-sn-glycerol (OAG)- and Endothelin-1 (ET-1)-induced melanogenesis without cellular toxicity. Mushroom tyrosinase activity assay showed that FGIN-1-27 did not directly inhibit tyrosinase activity, which suggested that FGIN-1-27 was not a direct inhibitor of tyrosinase. Although it was not capable of modulating the catalytic activity of mushroom tyrosinase in vitro, FGIN-1-27 downregulated the expression levels of key proteins that function in melanogenesis. FGIN-1-27 played these functions mainly by suppressing the PKA/CREB, PKC-β, and MAPK pathways. Once inactivated, it decreased the expression of MITF, tyrosinase, TRP-1, TRP-2, and inhibited the tyrosinase activity, finally inhibiting melanogenesis. During in vivo experiments, FGIN-1-27 inhibited the body pigmentation of zebrafish and reduced UVB-induced hyperpigmentation in guinea pig skin, but not a reduction of numbers of melanocytes. Our findings indicated that FGIN-1-27 exhibited no cytotoxicity and inhibited melanogenesis in both in vitro and in vivo models. It may prove quite useful as a safer skin-whitening agent.

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