Ethanol-mediated stimulation of HCV replication in vitro: Role of MAP Kinase activity and generation of radical oxygen species

Serum and glucocorticoid regulated kinase 1 (SGK1) has been identified as a key regulatory protein that controls a diverse set of cellular processes including sodium (Na+) homeostasis, osmoregulation, cell survival, and cell proliferation. Two other SGK isoforms, SGK2 and SGK3, have been identified, which differ most markedly from SGK1 in their NH2-terminal domains. We found that SGK1 and SGK3 are potent stimulators of epithelial Na+ channel (ENaC)-dependent Na+ transport, while SGK2, which has a short NH2 terminus, is a weak stimulator of ENaC. Further characterization of the role of the SGK1 NH2 terminus revealed that its deletion does not affect in vitro kinase activity but profoundly limits the ability of SGK1 either to stimulate ENaC-dependent Na+ transport or inhibit Forkhead-dependent gene transcription. The NH2 terminus of SGK1, which shares sequence homology with the phosphoinositide 3-phosphate [PI( 3 )P] binding domain of SGK3, binds phosphoinositides in protein lipid overlay assays, interacting specifically with PI( 3 )P, PI( 4 )P, and PI( 5 )P, but not with PI( 3 , 4 , 5 )P3. Moreover, a point mutation that reduces phosphoinositide binding to the NH2 terminus also reduces SGK1 effects on Na+ transport and Forkhead activity. These data suggest that the NH2 terminus, although not required for PI 3-kinase-dependent modulation of SGK1 catalytic activity, is required for multiple SGK1 functions, including stimulation of ENaC and inhibition of the proapoptotic Forkhead transcription factor. Together, these observations support the idea that the NH2-terminal domain acts downstream of PI 3-kinase-dependent activation to target the kinase to specific cellular compartments and/or substrates, possibly through its interactions with a subset of phosphoinositides.

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Rapid stimulation of mitogen-activated protein kinase of rat liver by prolactin

Biochemical Journal ◽

10.1042/bj3030429 ◽

1994 ◽

Vol 303 (2) ◽

pp. 429-433 ◽

Cited By ~ 37

Author(s):

R Piccoletti ◽

P Maroni ◽

P Bendinelli ◽

A Bernelli-Zazzera

Keyword(s):

Protein Kinase ◽

Map Kinase ◽

Tyrosine Kinases ◽

Kinase Activity ◽

Mitogen Activated Protein Kinase ◽

Female Rats ◽

Protein Kinase Activity ◽

Kinase Activation ◽

Stimulation Of

Intraperitoneal prolactin administration to female rats caused a rapid and transient stimulation of hepatic mitogen-activated kinase (MAP kinase) activity measured in vitro as cytosolic phosphotransferase capacity towards two specific substrates. Myelin basic protein kinase activity of MAP kinase immunoprecipitates confirmed the specificity and magnified the prolactin effect. Immunoblot experiments with anti-(MAP kinase) and anti-phosphotyrosine antibodies showed changes in both electrophoretic mobility and phosphotyrosine content of 40 and 44 kDa isoenzymes suggesting that prolactin affects these isoforms. Concomitant with the increase in MAP kinase activity, prolactin induced tyrosine phosphorylation in a number of liver proteins, suggesting a rapid involvement of tyrosine kinases which might be correlated in some way with MAP kinase activation. Protein kinase C activity, which has been implicated in the regulation of MAP kinase and in mediating the prolactin effect, does not seem to participate in MAP kinase activation.

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Activation of bovine oocytes by protein synthesis inhibitors: new findings on the role of MPF/MAPKs†

Biology of Reproduction ◽

10.1093/biolre/ioab019 ◽

2021 ◽

Author(s):

Cecilia Valencia ◽

Felipe Alonso Pérez ◽

Carola Matus ◽

Ricardo Felmer ◽

María Elena Arias

Keyword(s):

Protein Synthesis ◽

Kinase Activity ◽

Cyclin B1 ◽

Protein Synthesis Inhibitors ◽

Vitro Fertilization ◽

New Findings ◽

Bovine Oocytes ◽

Dependent Pathway

Abstract The present study evaluated the mechanism by which protein synthesis inhibitors activate bovine oocytes. The aim was to analyze the dynamics of MPF and MAPKs. MII oocytes were activated with ionomycin (Io), ionomycin+anisomycin (ANY) and ionomycin+cycloheximide (CHX) and by in vitro fertilization (IVF). The expression of cyclin B1, p-CDK1, p-ERK1/2, p-JNK, and p-P38 were evaluated by immunodetection and the kinase activity of ERK1/2 was measured by enzyme assay. Evaluations at 1, 4, and 15 hours postactivation (hpa) showed that the expression of cyclin B1 was not modified by the treatments. ANY inactivated MPF by p-CDK1Thr14-Tyr15 at 4 hpa (P < 0.05), CHX increased pre-MPF (p-CDK1Thr161 and p-CDK1Thr14-Tyr15) at 1 hpa and IVF increased p-CDK1Thr14-Tyr15 at 17 hours postfertilization (hpf) (P < 0.05). ANY and CHX reduced the levels of p-ERK1/2 at 4 hpa (P < 0.05) and its activity at 4 and 1 hpa, respectively (P < 0.05). Meanwhile, IVF increased p-ERK1/2 at 6 hpf (P < 0.05); however, its kinase activity decreased at 6 hpf (P < 0.05). p-JNK in ANY, CHX, and IVF oocytes decreased at 4 hpa (P < 0.05). p-P38 was only observed at 1 hpa, with no differences between treatments. In conclusion, activation of bovine oocytes by ANY, CHX, and IVF inactivates MPF by CDK1-dependent specific phosphorylation without cyclin B1 degradation. ANY or CHX promoted this inactivation, which seemed to be more delayed in the physiological activation (IVF). Both inhibitors modulated MPF activity via an ERK1/2-independent pathway, whereas IVF activated the bovine oocytes via an ERK1/2-dependent pathway. Finally, ANY does not activate the JNK and P38 kinase pathways.

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Mitochondrion-Dependent Cell Death in TDP-43 Proteinopathies

Biomedicines ◽

10.3390/biomedicines9040376 ◽

2021 ◽

Vol 9 (4) ◽

pp. 376

Author(s):

Chantal B. Lucini ◽

Ralf J. Braun

Keyword(s):

Cell Death ◽

Oxygen Species ◽

In Vivo Models ◽

Dependent Cell ◽

Cell Death Mechanisms ◽

Sting Pathway ◽

Mitochondrial Membrane Permeabilization

In the last decade, pieces of evidence for TDP-43-mediated mitochondrial dysfunction in neurodegenerative diseases have accumulated. In patient samples, in vitro and in vivo models have shown mitochondrial accumulation of TDP-43, concomitantly with hallmarks of mitochondrial destabilization, such as increased production of reactive oxygen species (ROS), reduced level of oxidative phosphorylation (OXPHOS), and mitochondrial membrane permeabilization. Incidences of TDP-43-dependent cell death, which depends on mitochondrial DNA (mtDNA) content, is increased upon ageing. However, the molecular pathways behind mitochondrion-dependent cell death in TDP-43 proteinopathies remained unclear. In this review, we discuss the role of TDP-43 in mitochondria, as well as in mitochondrion-dependent cell death. This review includes the recent discovery of the TDP-43-dependent activation of the innate immunity cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS/STING) pathway. Unravelling cell death mechanisms upon TDP-43 accumulation in mitochondria may open up new opportunities in TDP-43 proteinopathy research.

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A Novel Tetrapeptide Derivative Exhibits In Vitro Inhibition of Neutrophil-Derived Reactive Oxygen Species and Lysosomal Enzymes Release

Oxidative Medicine and Cellular Longevity ◽

10.1155/2013/853210 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Sumitra Miriyala ◽

Manikandan Panchatcharam ◽

Meera Ramanujam ◽

Rengarajulu Puvanakrishnan

Keyword(s):

Reactive Oxygen Species ◽

Superoxide Anion ◽

Lysosomal Enzymes ◽

Reactive Oxygen ◽

Peptide Sequence ◽

Ros Generation ◽

Oxygen Species ◽

Complement Factors

Neutrophil infiltration plays a major role in the pathogenesis of myocardial injury. Oxidative injury is suggested to be a central mechanism of the cellular damage after acute myocardial infarction. This study is pertained to the prognostic role of a tetrapeptide derivative PEP1261 (BOC-Lys(BOC)-Arg-Asp-Ser(tBu)-OtBU), a peptide sequence (39–42) of lactoferrin, studied in the modulation of neutrophil functions in vitro by measuring the reactive oxygen species (ROS) generation, lysosomal enzymes release, and enhanced expression of C proteins. The groundwork experimentation was concerned with the isolation of neutrophils from the normal and acute myocardial infarct rats to find out the efficacy of PEP1261 in the presence of a powerful neutrophil stimulant, phorbol 12-myristate 13 acetate (PMA). Stimulation of neutrophils with PMA resulted in an oxidative burst of superoxide anion and enhanced release of lysosomal enzymes and expression of complement proteins. The present study further demonstrated that the free radicals increase the complement factors in the neutrophils confirming the role of ROS. PEP1261 treatment significantly reduced the levels of superoxide anion and inhibited the release of lysosomal enzymes in the stimulated control and infarct rat neutrophils. This study demonstrated that PEP1261 significantly inhibited the effect on the ROS generation as well as the mRNA synthesis and expression of the complement factors in neutrophils isolated from infarct heart.

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The Role of Interleukin-23 in the Early Development of Emphysema in HIV1+Smokers

Journal of Immunology Research ◽

10.1155/2016/3463104 ◽

2016 ◽

Vol 2016 ◽

pp. 1-14 ◽

Cited By ~ 3

Author(s):

Igor Z. Barjaktarevic ◽

Ronald G. Crystal ◽

Robert J. Kaner

Keyword(s):

Tissue Destruction ◽

Epithelial Lining Fluid ◽

Protein Levels ◽

Knowing That ◽

Lung Epithelial ◽

Interleukin 23 ◽

Metalloproteinase 9 ◽

Stimulation Of

Rationale.Matrix metalloproteinase-9 (MMP-9) expression is upregulated in alveolar macrophages (AM) of HIV1+smokers who develop emphysema. Knowing that lung epithelial lining fluid (ELF) of HIV1+smokers contains increased levels of inflammatory cytokines compared to HIV1−smokers, we hypothesized that upregulation of lung cytokines in HIV1+smokers may be functionally related to increased MMP-9 expression.Methods.Cytokine arrays evaluated cytokine protein levels in ELF obtained from 5 groups of individuals: HIV1−healthy nonsmokers, HIV1−healthy smokers, HIV1−smokers with low diffusing capacity (DLCO), HIV1+nonsmokers, and HIV1+smokers with lowDLCO.Results. Increased levels of the Th17 related cytokine IL-23 were found in HIV1−smokers with lowDLCOand HIV1+smokers and nonsmokers. Relative IL-23 gene expression was increased in AM of HIV1+individuals, with greater expression in AM of HIV1+smokers with lowDLCO. Infection with HIV1in vitroinduced IL-23 expression in normal AM. IL-23 stimulation of AM/lymphocyte coculturesin vitroinduced upregulation of MMP-9. Lung T lymphocytes express receptor IL-23R and interact with AM in order to upregulate MMP-9.Conclusion. This mechanism may contribute to the increased tissue destruction in the lungs of HIV1+smokers and suggests that Th17 related inflammation may play a role.

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Reactive Oxygen Species-Mediated Homologous Downregulation of Angiotensin II Type 1 Receptor Mrna by Angiotensin II

Hypertension ◽

10.1161/hyp.36.suppl_1.688-b ◽

2000 ◽

Vol 36 (suppl_1) ◽

pp. 688-688

Author(s):

Toshihiro Ichiki ◽

Kotaro Takeda ◽

Akira Takeshita

Keyword(s):

Reactive Oxygen Species ◽

Angiotensin Ii ◽

Nadph Oxidase ◽

Mrna Expression ◽

Crucial Role ◽

Oxygen Species ◽

Ang Ii ◽

Stimulation Of

58 Recent studies suggest a crucial role of reactive oxygen species (ROS) for the signaling of Angiotensin II (Ang II) through type 1 Ang II receptor (AT1-R). However, the role of ROS in the regulation of AT1-R expression has not been explored. In this study, we examined the effect of an antioxidant on the homologous downregulation of AT1-R by Ang II. Ang II (10 -6 mol/L) decreased AT1-R mRNA with a peak suppression at 6 hours of stimulation in rat aortic vascular smooth muscle cells (VSMC). Ang II dose-dependently (10 -8 -10 -6 ) suppressed AT1-R mRNA at 6 hours of stimulation. Preincubation of VSMC with N-acetylcysteine (NAC), a potent antioxidant, almost completely inhibited the Ang II-induced downregulation of AT1-R mRNA. The effect of NAC was due to stabilization of the AT1-R mRNA that was destabilized by Ang II. Ang II did not affect the promoter activity of AT1-R gene. Diphenylene iodonium (DPI), an inhibitor of NADH/NADPH oxidase failed to inhibit the Ang II-induced AT1-R mRNA downregulation. The Ang II-induced AT1-R mRNA downregulation was also blocked by PD98059, an extracellular signal-regulated protein kinase (ERK) kinase inhibitor. Ang II-induced ERK activation was inhibited by NAC as well as PD98059 whereas DPI did not inhibit it. To confirm the role of ROS in the regulation of AT1-R mRNA expression, VSMC were stimulated with H 2 O 2 . H 2 O 2 suppressed the AT1-R mRNA expression and activated ERK. These results suggest that production of ROS and activation of ERK are critical for downregulation of AT1-R mRNA. The differential effect of NAC and DPI on the downregulation of AT1-R mRNA may suggest the presence of other sources than NADH/NADPH oxidase pathway for ROS in Ang II signaling. Generation of ROS through stimulation of AT1-R not only mediates signaling of Ang II but may play a crucial role in the adaptation process of AT1-R to the sustained stimulation of Ang II.

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Protective role of epithelium in the guinea pig airway

Journal of Applied Physiology ◽

10.1152/jappl.1989.66.4.1547 ◽

1989 ◽

Vol 66 (4) ◽

pp. 1547-1552 ◽

Cited By ~ 68

Author(s):

M. Munakata ◽

I. Huang ◽

W. Mitzner ◽

H. Menkes

Keyword(s):

Guinea Pig ◽

Protective Role ◽

Airway Epithelial ◽

Serosal Side ◽

Epithelial Surface ◽

Airway Responses ◽

Airway Tone ◽

Stimulation Of

We developed an in vitro system to assess the role of the epithelium in regulating airway tone using the intact guinea pig trachea (J. Appl. Physiol. 64: 466–471, 1988). This method allows us to study the response of the airway when its inner epithelial surface or its outer serosal surface is stimulated independently. Using this system we evaluated how the presence of intact epithelium can affect pharmacological responsiveness. We first examined responses of tracheae with intact epithelium to histamine, acetylcholine, and hypertonic KCl when stimulated from the epithelial or serosal side. We then examined the effect of epithelial denudation on the responses to these agonists. With an intact epithelium, stimulation of the inner epithelial side always caused significantly smaller changes in diameter than stimulation of the outer serosal side. After mechanical denudation of the epithelium, these differences were almost completely abolished. In the absence of intact epithelium, the trachea was 35-fold more sensitive to histamine and 115-fold more sensitive to acetylcholine when these agents were applied to the inner epithelial side. In addition, the presence of an intact epithelium almost completely inhibited any response to epithelial side challenge with hypertonic KCl. These results indicate that the airway epithelial layer has a potent protective role in airway responses to luminal side stimuli, leading us to speculate that changes in airway reactivity measured in various conditions including asthma may result in part from changes in epithelial function.

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Inhibition of the MAP kinase activity suppresses estrogen-induced breast tumor growth both in vitro and in vivo

International Journal of Oncology ◽

10.3892/ijo.30.4.971 ◽

2007 ◽

Author(s):

Kaladhar Reddy ◽

Selina Glaros

Keyword(s):

Tumor Growth ◽

Map Kinase ◽

Breast Tumor ◽

Kinase Activity

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The Role of Monocytes/Macrophages In The Pathogenesis of Immune Associated Diffuse Alveolar Hemorrhage

10.21203/rs.3.rs-521383/v1 ◽

2021 ◽

Author(s):

Qing Wei ◽

Xun Chen ◽

Jing Liu ◽

Yan Li ◽

Guangmin Nong

Keyword(s):

Flow Cytometry ◽

Critical Role ◽

Lavage Fluid ◽

Peripheral Blood Monocyte ◽

Healthy Children ◽

Group 3 ◽

Group 2 ◽

Stimulation Of

Abstract Backgroud The studies in the immnue associated diffuse alveolar hemorrahge (DAH) animal models showed that monocytes/macrophages played an critical role in the pathogenesis.Whether monocytes/macrophages contribute to the pathogenesis of immune associated DAH in human is still unknow. The aim of this study was to explore the role of monocytes/macrophages in the pathogenesis of immune associated DAH in human.Methods This study was conducted in two parts. In the first part, 37 children with immune associated DAH were included (DAH group), and 18 healthy children were recruited as the controls (HC group). Peripheral blood monocyte subtype was analyzed using flow cytometry. In the second part, 24 children with immune associated DAH were included (DAH group), and 13 children with acute airway foreingn body or mild benign airway stenosis were included as the controls (HC group). Bronochoalveolar lavage fluid (BALF) was collected using bronchoscope. Cytokines in the BALF supernatant were detected using cytometric bread array. BALF supertanant was used to stimulated the macrophages in vitro. The mRNA relative expressions of IL-1β, TNFα, IL-6, TGM2, CD163 and MRC1 were detected using quantitative real-time PCR, and the expressions of CD14, CD80, CD86, CD163 and CD206 were detected using flow cytometry. Results 1. The percentage of classical monocyte was significantly increased, whereas the percentages of intermediate and non-classical monocyte were significantly decreased in the DAH group, when compared to those in the HC group. 2. The levels of MCP-1, IL-6 and IL-8 were all significantly higher in the BALF supernatant from the DAH group, when compared to those form the HC group. 3. The mRNA relative expressions of IL-1β and IL-6 as well as the expression of CD86 were significantly higher, whereas the mRNA relative expression of MRC1 as well as the expressions of CD163 and CD206 were significantly lower under the stimulation of BALF supernatant from the DAH group, when compared to that from the HC group. Conclusions Monocytes/macrophages might participate in the pathogenesis of immune associated DAH in human by enhanced M1 polarization.

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