Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.1 (ERK)
 95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

HSP70 is a member of the heat shock protein family and is induced by various types of cellular stress. We examined whether HSP70 might play a role in the healing of corneal epithelial wounds. Given that the PHSRN peptide, which corresponds to the second cell-binding domain of fibronectin, promotes corneal epithelial migration, we investigated the effect of this peptide on HSP70 expression in cultured human corneal epithelial cells. Reverse transcription-polymerase chain reaction and immunoblot analyses revealed that PHSRN increased the amounts of HSP70 mRNA and protein in these cells in a concentration- and time-dependent manner, whereas a control peptide (NRSHP) had no such effects. Furthermore, the PHSRN-induced up-regulation of HSP70 was blocked by SB203580, an inhibitor of p38 mitogen-activated protein kinase (MAPK), but it was not affected by PD98059 or SP600125, inhibitors of signaling by the MAPKs ERK and JNK, respectively. Our results suggest that induction of HSP70 expression may contribute to the promotion of corneal epithelial migration by PHSRN and hence to corneal epithelial wound healing.
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PMID:Up-regulation of HSP70 by the fibronectin-derived peptide PHSRN in human corneal epithelial cells. 1837 59

Insulin regulates metabolism and growth in cells of hepatic origin by specifically binding to and activating the tyrosine kinase insulin receptor. Insulin-induced intracellular signaling is conducted via multiple pathways, including the MAP kinase (MEK/ERK) and the phosphatidylinositol 3-kinase (PI3K) pathways, which in turn activate multiple downstream signaling molecules. Heat shock protein 60 (HSP60; chaperonin 60kD) was selected by screening to be regulated by insulin in rat hepatoma cells. Heat shock proteins are a family of molecular chaperones whose main cellular function is to mediate the proper folding of newly synthesized proteins. The cellular response to stress is characterized by an overall decrease in protein synthesis, and upregulation of the heat shock protein family, including HSP60. A role for HSP60 has been implied in many diseases and in the responses to hypoxia. The present study was designed to ask whether insulin stimulated HSP60 gene expression. The rate of HSP60 transcription and mRNA accumulation were measured in rat H4IIE hepatoma cells and insulin-induced expression of HSP60 was predominantly via the MEK/ERK pathway. Inhibition of the p38 and PI3K pathways suggest complex feedback interactions of other insulin-, cell stressor- and cytokine- regulated pathways on the primary role of the MEK/ERK signaling in the regulation of HSP60 gene expression by insulin.
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PMID:Insulin Dependant Gene Expression of Heat Shock Protein 60 in H4IIE Hepatoma Cells. 1907 90

Overexpression of the human epidermal growth factor receptor 2 (HER-2) represents a biological subclass of breast cancer with distinct molecular alterations, clinical behavior, and response to systemic therapy. Trastuzumab is a monoclonal antibody directed against HER-2 which has revolutionized the management of both early and advanced breast cancer. It may exert its anti-cancer effects through inhibition of intracellular signaling, upregulation of p27, impaired angiogenesis, induction of immune-mediated destruction, and blockade of cleavage of the extracellular domain of HER-2. In spite of its robust clinical activity, most women with metastatic HER-2 overexpressing breast cancer eventually progress on trastuzumab therapy. Possible mechanisms of resistance include: altered receptor antibody interaction, PTEN loss and enhanced Akt signaling, p27 loss, signaling through other receptors. Preclinical experiments, clinical experience with the use of trastuzumab beyond progression, and a recent phase III clinical trial with Lapatinib, a dual EGFR/HER-2 tyrosine kinase inhibitor, demonstrate that the HER-2 signaling axis remains an important therapeutic target even after progression on trastuzumab. A variety of novel strategies are currently in development to exploit this pathway following the onset of resistance, such as receptor antibodies, sheddase inhibitors, signal transduction inhibitors, heat shock protein inhibitors, proteasome inhibitors, anti-angiogenic agents, and immune-stimulatory therapies, either as single agents or in combination with trastuzumab. Rational clinical trial design, with attention to appropriate patient selection and prospective collection of biological material, is needed to ensure that the new generation of anti-HER-2 targeted therapies realizes its promise in the treatment of trastuzumab-resistant disease.
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PMID:Beyond trastuzumab: overcoming resistance to targeted HER-2 therapy in breast cancer. 1927 56

Macrolide antibiotics are known to have a variety of immunomodulatory effects in addition to antimicrobial activity, but the mechanisms of immunomodulation are still unclear. We investigated in vitro the effect of azithromycin on tumor necrosis factor alpha (TNF-alpha) production in lipopolysaccharide (LPS)-stimulated THP-1 cells, a human monocytic cell line, and compared the results with those for other macrolides, minocycline and ofloxacin. In the presence of LPS, treatment with azithromycin (AZM) resulted in a significant decrease in LPS-induced TNF-alpha production compared to that with other antimicrobial agents. the results of phosphorylation of three MAPKs, ERK, JNK and p38, indicated that the phospho-p38 level was reduced by AZM. Ikappab-alpha, an inhibitor of NFkappab, was not disrupted by the antibiotics. LPS-induced TNF-alpha release from THP-1 cells was inhibited in the presence of KNK437, a potent 70-kDa heat shock protein (HSP-70) inhibitor. Interestingly, the induction of HSP-70 by LPS was attenuated with the concurrent addition of AZM in the cells. AZM was found to restrain TNF-alpha production by monocytes at least in part by modifying the HSp-70 and p38 related signaling pathways to LPS stimulation.
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PMID:Azithromycin reduces tumor necrosis factor-alpha production in lipopolysaccharide-stimulated THP-1 monocytic cells by modification of stress response and p38 MAPK pathway. 1962 57

Human epidermal growth factor receptor (HER)2 over-expression is associated with a shortened disease-free interval and poor survival. Although the addition of trastuzumab to chemotherapy in the first-line setting has improved response rates, progression-free survival, and overall survival, response rates declined when trastuzumab was used beyond the first-line setting because of multiple mechanisms of resistance. Studies have demonstrated the clinical utility of continuing trastuzumab beyond progression, and further trials to explore this concept are ongoing. New tyrosine kinase inhibitors, monoclonal antibodies, PTEN (phosphatase and tensin homolog) pathway regulators, HER2 antibody-drug conjugates, and inhibitors of heat shock protein-90 are being evaluated to determine whether they may have a role to play in treating trastuzumab-resistant metastatic breast cancer.
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PMID:Recent advances in systemic therapy: Advances in systemic therapy for HER2-positive metastatic breast cancer. 1976 84

17-Allylamino, 17-demethoxygeldanamycin (17-AAG), an effective inhibitor of the heat shock protein hsp90, preferentially inhibiting tumor hsp90 compared to hsp90 from normal cells, has shown promising results against several cancers, including hormone-resistant prostate cancer. Levels of several oncogenic proteins critical to tumor growth and progression, such as androgen receptor and HER2/neu, were reduced 4 h post 17-allylamino, 17-demethoxygeldanamycin treatment. Posttreatment metabolic changes have also been observed in several tumor cell lines. In this study, total choline distributions in hormone sensitive CWR22 and hormone resistant CWR22r prostate cancer xenograft tumors in mice were measured before and at 4 h and 48 h after a single-bolus 17-allylamino, 17-demethoxygeldanamycin treatment at 100 mg/kg, using proton MR spectroscopy. Our results show that tumor total choline levels declined 4 h after the treatment for CWR22 (P = 0.001) and 48 h post treatment for CWR22r (P = 0.003). Metabolic changes, in particular of total choline intensity detected by proton magnetic resonance spectroscopic imaging (MRSI), are consistent with the observed immunohistochemistry changes, tumor growth inhibition for CWR22r (P = 0.01 at 14 days post treatment), and a constant prostate specific antigen level versus increasing prostate specific antigen for control CWR22 (P = 0.01). Metabolic changes in total choline by proton MRSI can be used as an early biomarker of response for advanced-stage prostate cancer in targeted therapy such as 17-allylamino, 17-demethoxygeldanamycin.
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PMID:Proton MRS detects metabolic changes in hormone sensitive and resistant human prostate cancer models CWR22 and CWR22r. 1978 Jan 65

Cadmium is one of the most toxic elements to which man can be exposed at work or in the environment. By far, the most salient toxicological property of Cd is its exceptionally long half-life in the human body. Once absorbed, Cd accumulates in the human body, particularly in the liver and other vital organs. The cellular actions of Cd are extensively documented, but the molecular mechanisms underlying these actions are still not resolved. It is known that Cd activates the activator protein-1 (AP-1), but no data about the pathway involved are reported for liver. The objective was to provide a greater insight into the effect of cadmium on mitogen-activated protein kinases (MAPK's) involved in signal transduction, its relationship with AP-1 activation, and heat shock protein (Hsp) 70 expression, in HepG2 cells. AP-1 activation as a result of 5 microM CdCl(2) exposure was increased 24.5-fold over control cells after 4 h treatment. To investigate the role of the extracellular signal-regulated protein kinases (ERK's), c-Jun N-terminal kinases (JNK's) and p38 kinases in cadmium-induced AP-1 activation, specific MAPKs inhibitors were used. AP-1 activation decreased by 74% with ERK inhibition, by 83% with p38 inhibition, while inhibition of JNK decreased by 70%. Only ERK and JNK participated in Hsp70 production, conferring cell protection against cadmium damage.
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PMID:MAPK activation is involved in cadmium-induced Hsp70 expression in HepG2 cells. 1981 60

The effects of dietary exposure to organic anions on the physiology of isolated Malpighian tubules and on tubule gene expression were examined using larvae of Drosophila melanogaster. Acute (24 h) or chronic (7 d) exposure to type I organic anions (fluorescein or salicylate) was associated with increased fluid secretion rates and increased fluxes of both salicylate and the type II organic anion methotrexate. By contrast, chronic exposure to dietary methotrexate was associated with increased fluid secretion rate and increased flux of methotrexate, but not salicylate. Exposure to methotrexate in the diet resulted in increases in the expression of a multidrug efflux transporter gene (MET; CG30344) in the Malpighian tubules. There were also increases in expression of genes for either a Drosophila multidrug resistance-associated protein (dMRP; CG6214) or an organic anion transporting polypeptide (OATP; CG3380), depending on the concentration of methotrexate in the diet. Exposure to salicylate in the diet was associated with an increase in expression of dMRP and with decreases of MET and OATP. Exposure to dietary salicylate or methotrexate was also associated with different patterns of expression of heat shock protein genes. The results suggest that exposure to specific type I or type II organic anions has multiple effects and results not only in increased organic anion transport but also in increased rates of inorganic ion transport, which drives osmotically-obliged fluid secretion. Increased fluid secretion may enhance secretion of organic anions by eliminating diffusive backflux from the tubule lumen to the hemolymph.
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PMID:Effects of acute or chronic exposure to dietary organic anions on secretion of methotrexate and salicylate by Malpighian tubules of Drosophila melanogaster larvae. 2007 73

Exercise preconditioning induces neuroprotection after stroke. We investigated the beneficial role of heat shock protein-70 (HSP-70) and phosphorylated extracellular-signal-regulated-kinase 1/2 (pERK 1/2), as they pertain to reducing apoptosis and their influence on Bcl-x(L), Bax, and apoptosis-inducing factor (AIF) in rats subjected to ischemia and reperfusion. Adult male Sprague-Dawley rats were subjected to 30 min of exercise on a treadmill for 1, 2, or 3 weeks. Stroke was induced by a 2-h middle cerebral artery (MCA) occlusion using an intraluminal filament. Protein levels of HSP-70, pERK 1/2, Bcl-x(L), Bax, and AIF were analyzed using Western blot. Neuroprotection was based on levels of apoptosis (TUNEL) and infarct volume (Nissl staining). Immunocytochemistry was used for cellular expression of HSP-70 and pERK 1/2. Significant (P<0.05) up-regulation of HSP-70 and pERK 1/2 after 3 weeks of exercise coincided with significant (P<0.05) reduction in neuronal apoptosis and brain infarct volume. Inhibition of either one of these two factors showed a significant (P<0.05) reversal in the neuroprotection. Bax and AIF were down-regulated, while levels of Bcl-x(L) were up-regulated in response to stroke after exercise. Inhibiting HSP-70 or pERK 1/2 reversed this resultant increase or decrease. Our results indicate that exercise diminishes neuronal injury in stroke by up-regulating HSP-70 and ERK 1/2.
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PMID:Exercise preconditioning reduces neuronal apoptosis in stroke by up-regulating heat shock protein-70 (heat shock protein-72) and extracellular-signal-regulated-kinase 1/2. 2008 67

The objectives of this study were to investigate the early response to mechanical stress in neonatal rat mandibular chondrocytes by proteomic analysis. To evaluate its molecular mechanism, chondrocytes were isolated and cultured in vitro, then loaded mechanical stress by four-point bending system on different patterns. Morphological observation, flow cytometric analysis, and MTT assays indicated that 4,000 microstrain loading for 60 min was an appropriate mechanical stimulus for the following proteome analysis, which produced a transient but obvious inhibitory effect on the cell cycle. Therefore, we took a proteomic approach to identify significantly differential expression proteins in chondrocytes under this mechanical stress. Using 2-DE and MALDI-TOF, we identified seven differentially expressed proteins including the MAPK pathway inhibitor RKIP, cytoskeleton proteins, actin and vimentin, and other selected proteins. Some differentially expressed proteins were validated by both Western blot analysis and fluorescent staining of cytoskeleton at different loading times. The vimentin and RKIP responsive expression were also proven in vivo in oral orthopedic treatment rats, which was in line with the result in vitro. The histological changes in cartilage also showed the inhibition effect. Furthermore, the expressional level of phosphorylated ERK was increased, which demonstrates the changes in MAPK activity. Taken together, these data indicate that mechanical stress resulted in vimentin expression changes first and then led to the subsequent changes in actin expression, MAPK pathway regulated by RKIP and heat shock protein GRP75. All those changes contributed to the cytoskeleton remolding and cell cycle inhibition, finally led to condylar remodeling.
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PMID:Proteomic analysis of early-response to mechanical stress in neonatal rat mandibular condylar chondrocytes. 2012 8


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