Search results for "Mitogen-Activated Protein Kinases"
showing 10 items of 246 documents
The nucleotide excision repair protein XPC is essential for bulky DNA adducts to promote interleukin-6 expression via the activation of p38-SAPK
2016
Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants, and many are potent carcinogens. Benzo[a]pyrene (B[a]P), one of the best-studied PAHs, is metabolized ultimately to the genotoxin anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE). BPDE triggers stress responses linked to gene expression, cell death and survival. So far, the underlying mechanisms that initiate these signal transduction cascades are unknown. Here we show that BPDE-induced DNA damage is recognized by DNA damage sensor proteins to induce activation of the stress-activated protein kinase (SAPK) p38. Surprisingly, the classical DNA damage response, which involves the kinases ATM and ATR, is not involved in p38-SA…
Muscle follistatin gene delivery increases muscle protein synthesis independent of periodical physical inactivity and fasting
2020
Blocking of myostatin and activins effectively counteracts muscle atrophy. However, the potential interaction with physical inactivity and fasting in the regulation of muscle protein synthesis is poorly understood. We used blockade of myostatin and activins by recombinant adeno-associated virus (rAAV)-mediated follistatin (FS288) overexpression in mouse tibialis anterior muscle. To investigate the effects on muscle protein synthesis, muscles were collected 7 days after rAAV-injection in the nighttime or in the daytime representing high and low levels of activity and feeding, respectively, or after overnight fasting, refeeding, or ad libitum feeding. Muscle protein synthesis was increased by…
p38 MAPK Controls Prothrombin Expression by Regulated RNA 3′ End Processing
2011
Thrombin is a key protease involved in blood coagulation, complement activation, inflammation, angiogenesis, and tumor invasion. Although induced in many (patho-)physiological conditions, the underlying mechanisms controlling prothrombin expression remained enigmatic. We have now discovered that prothrombin expression is regulated by a posttranscriptional regulatory mechanism responding to stress and inflammation. This mechanism is triggered by external stimuli that activate p38 MAPK. In turn, p38 MAPK upmodulates canonical 3' end processing components and phosphorylates the RNA-binding proteins FBP2 and FBP3, which inhibit 3' end processing of mRNAs, such as prothrombin mRNA, that bear a d…
Activation of p38, p21, and NRF-2 Mediates Decreased Proliferation of Human Dental Pulp Stem Cells Cultured under 21% O2
2014
Summary High rates of stem cell proliferation are important in regenerative medicine and in stem cell banking for clinical use. Ambient oxygen tensions (21% O2) are normally used for in vitro culture, but physiological levels in vivo range between 3% and 6% O2. We compared proliferation of human dental pulp stem cells (hDPSCs) cultured under 21% versus 3% O2. The rate of hDPSC proliferation is significantly lower at 21% O2 compared to physiological oxygen levels due to enhanced oxidative stress. Under 21% O2, increased p38 phosphorylation led to activation of p21. Increased generation of reactive oxygen species and p21 led to activation of the NRF-2 signaling pathway. The upregulation of NR…
Inhibition of Xanthine Oxidase by Allopurinol Prevents Skeletal Muscle Atrophy: Role of p38 MAPKinase and E3 Ubiquitin Ligases
2012
International audience; Abstract Top Alterations in muscle play an important role in common diseases and conditions. Reactive oxygen species (ROS) are generated during hindlimb unloading due, at least in part, to the activation of xanthine oxidase (XO). The major aim of this study was to determine the mechanism by which XO activation causes unloading-induced muscle atrophy in ratsand its possible prevention by allopurinol, a well-known inhibitor of this enzyme. For this purpose we studied one of the main redox sensitive signalling cascades involved in skeletal muscle atrophy i.e. p38 MAPKinaseand the expression of two well known muscle specific E3 ubiquitin ligases involved in proteolysis, …
Differential expression of PGC-1α and metabolic sensors suggest age-dependent induction of mitochondrial biogenesis in Friedreich ataxia fibroblasts.
2011
11 pages, 6 figures. PMID:21687738[PubMed] PMCID: PMC3110204
Effect of gender on mitochondrial toxicity of Alzheimer's Abeta peptide.
2007
The aim of this article is to review the role of mitochondria in the pathogenesis of Alzheimer's disease. Additionally, the effect of gender on the incidence of Alzheimer's disease and the pathophysiological mechanisms involved will be discussed. Mitochondria, in the presence of Alzheimer's amyloid-beta peptide, increase the formation of reactive oxygen species which act both as damaging agents and also as signaling molecules. These radicals, in fact, unleash a mechanism involving the liberation of cytochrome c that leads to neuronal apoptosis. Notably, young females appear protected against the mitochondrial toxicity of amyloid-beta, likely due to the upregulation of antioxidant enzymes wh…
CB1 Cannabinoid Receptors and On-Demand Defense Against Excitotoxicity
2003
Abnormally high spiking activity can damage neurons. Signaling systems to protect neurons from the consequences of abnormal discharge activity have been postulated. We generated conditional mutant mice that lack expression of the cannabinoid receptor type 1 in principal forebrain neurons but not in adjacent inhibitory interneurons. In mutant mice,the excitotoxin kainic acid (KA) induced excessive seizures in vivo. The threshold to KA-induced neuronal excitation in vitro was severely reduced in hippocampal pyramidal neurons of mutants. KA administration rapidly raised hippocampal levels of anandamide and induced protective mechanisms in wild-type principal hippocampal neurons. These protecti…
p38 MAP kinase drives the expression of mast cell-derived IL-9 via activation of the transcription factor GATA-1.
2007
Mast cells are able to produce a huge panel of mediators including the Th2-type cytokine IL-9, which is considered to be a key mediator for the pathogenesis of allergic asthma, but detailed information on the regulation of IL-9 transcription in mast cells has been scarce. Herein we provide evidence that the erythroid/myeloid transcription factor GATA-1, which is not expressed in Th2 cells, is a potent activator of IL-9 expression in murine bone marrow-derived mast cells (BMMC). Furthermore, in mast cells, but not in Th2 cells, production of IL-9 is sensitive to inhibition of p38 MAP kinase. As transactivation mediated by GATA-1 is also sensitive to inhibition of p38 MAP kinase, and GATA-1 i…
Control of Cell Migration and Inflammatory Mediators Production by CORM-2 in Osteoarthritic Synoviocytes
2011
Background Osteoarthritis (OA) is the most widespread degenerative joint disease. Inflamed synovial cells contribute to the release of inflammatory and catabolic mediators during OA leading to destruction of articular tissues. We have shown previously that CO-releasing molecules exert anti-inflammatory effects in animal models and OA chondrocytes. We have studied the ability of CORM-2 to modify the migration of human OA synoviocytes and the production of chemokines and other mediators sustaining inflammatory and catabolic processes in the OA joint. Methodology/Principal Findings OA synoviocytes were stimulated with interleukin(IL)-1β in the absence or presence of CORM-2. Migration assay was…