Intracellular Signaling Pathways and Size, Shape, and Rupture History of Human Intracranial Aneurysms

Neurosurgery ◽  
2012 ◽  
Vol 70 (6) ◽  
pp. 1565-1573 ◽  
Author(s):  
Elisa Laaksamo ◽  
Manasi Ramachandran ◽  
Juhana Frösen ◽  
Riikka Tulamo ◽  
Marc Baumann ◽  
...  
Keyword(s):  
Intracellular Signaling ◽  
Mammalian Target Of Rapamycin ◽  
Morphological Features ◽  
Cellular Mechanisms ◽  
3 Dimensional ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Element Binding Protein ◽  
Angiographic Data ◽  
History Of

Abstract BACKGROUND: Size and morphological features are associated with intracranial aneurysm (IA) rupture. The cellular mechanisms of IA development and rupture are poorly known. OBJECTIVE: We studied the expression and phosphorylation of different intracellular signaling molecules in the IA wall compared with IA morphological features to understand better the cellular pathways involved in IA development and wall degeneration. METHODS: Nine ruptured and 17 unruptured human IA samples were collected intraoperatively. The expression levels and phosphorylation state of 3 mitogen-activated protein kinases (c-Jun N-terminal kinase [JNK], p38, extracellular signal-regulated kinase [ERK]), Bcl-2 antagonist of cell death (Bad), mammalian target of rapamycin (mTOR), cyclic AMP response element binding protein (CREB), and Akt were determined by Western blotting. The localization of signaling proteins was determined by immunofluorescence. From 3-dimensional segmentation of computed tomography angiographic data, size and shape indexes were calculated. RESULTS: We found a 5-fold difference in phospho-Bad levels between ruptured and unruptured IAs. Phospho-mTOR was downregulated 2.5-fold in ruptured IAs. Phospho-p54 JNK, phospho-p38, and phospho-Akt levels correlated positively with IA size. Phospho-CREB levels were significantly associated with nonsphericity and ellipticity indexes. Phospho-Akt and phospho-p38 correlated negatively with undulation index. CONCLUSION: The signaling pathway profile (apoptosis, cell proliferation, stress signaling) differs between ruptured and unruptured IAs and is associated with IA geometry. Our results increase the knowledge of IA development and wall degeneration.

scholarly journals TRAF6-Dependent Mitogen-Activated Protein Kinase Activation Differentially Regulates the Production of Interleukin-12 by Macrophages in Response to Toxoplasma gondii

2004 ◽  
Vol 72 (10) ◽  
pp. 5662-5667 ◽  
Author(s):  
Nicola J. Mason ◽  
Jim Fiore ◽  
Takashi Kobayashi ◽  
Katherine S. Masek ◽  
Yongwon Choi ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Toxoplasma Gondii ◽  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Interleukin 12 ◽  
Wild Type ◽  
Kinase Activation ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT The production of interleukin-12 (IL-12) is critical to the development of innate and adaptive immune responses required for the control of intracellular pathogens. Many microbial products signal through Toll-like receptors (TLR) and activate NF-κB family members that are required for the production of IL-12. Recent studies suggest that components of the TLR pathway are required for the production of IL-12 in response to the parasite Toxoplasma gondii; however, the production of IL-12 in response to this parasite is independent of NF-κB activation. The adaptor molecule TRAF6 is involved in TLR signaling pathways and associates with serine/threonine kinases involved in the activation of both NF-κB and mitogen-activated protein kinase (MAPK). To elucidate the intracellular signaling pathways involved in the production of IL-12 in response to soluble toxoplasma antigen (STAg), wild-type and TRAF6−/− mice were inoculated with STAg, and the production of IL-12(p40) was determined. TRAF6−/− mice failed to produce IL-12(p40) in response to STAg, and TRAF6−/− macrophages stimulated with STAg also failed to produce IL-12(p40). Studies using Western blot analysis of wild-type and TRAF6−/− macrophages revealed that stimulation with STAg resulted in the rapid TRAF6-dependent phosphorylation of p38 and extracellular signal-related kinase, which differentially regulated the production of IL-12(p40). The studies presented here demonstrate for the first time that the production of IL-12(p40) in response to toxoplasma is dependent upon TRAF6 and p38 MAPK.

Signaling through the extracellular signal-regulated kinase 1/2 cascade in cardiac myocytes

2004 ◽  
Vol 82 (6) ◽  
pp. 603-609 ◽  
Author(s):  
Angela Clerk ◽  
Peter H Sugden
Keyword(s):  
Cardiac Myocytes ◽  
Intracellular Signaling ◽  
Regulation Of Transcription ◽  
Signal Integration ◽  
Extracellular Signal Regulated Kinase ◽  
Kinase C ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Protein Kinase C Isoforms ◽  
Activate Protein Kinase

The extracellular signal-regulated kinases 1/2 (ERK1/2) are particularly implicated in the growth response of cardiac myocytes. In these cells, the ERK1/2 pathway is potently activated by Gq protein-coupled receptor agonists (such as endothelin-1 or α-adrenergic agonists), which activate protein kinase C isoforms. Here, we review the mechanisms associated with the activation of the ERK1/2 pathway by these agonists with particular emphasis on signal integration into the pathway. Signaling to the nucleus and the regulation of transcription factor activity associated with ERK1/2 activation in cardiac myocytes are also discussed.Key words: mitogen-activated protein kinases, cardiac myocytes, intracellular signaling.

scholarly journals Molecular Mechanisms of Cardiac Remodeling and Regeneration in Physical Exercise

Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1128 ◽  
Author(s):  
Dominik Schüttler ◽  
Sebastian Clauss ◽  
Ludwig T. Weckbach ◽  
Stefan Brunner
Keyword(s):  
Cardiac Function ◽  
Intracellular Signaling ◽  
Molecular Mechanisms ◽  
Cardiac Tissue ◽  
Mammalian Target Of Rapamycin ◽  
Cellular Mechanisms ◽  
Innovative Strategies ◽  
Muscle Strengthening ◽  
Positive Effects ◽  
Exercise Induced

Regular physical activity with aerobic and muscle-strengthening training protects against the occurrence and progression of cardiovascular disease and can improve cardiac function in heart failure patients. In the past decade significant advances have been made in identifying mechanisms of cardiomyocyte re-programming and renewal including an enhanced exercise-induced proliferational capacity of cardiomyocytes and its progenitor cells. Various intracellular mechanisms mediating these positive effects on cardiac function have been found in animal models of exercise and will be highlighted in this review. 1) activation of extracellular and intracellular signaling pathways including phosphatidylinositol 3 phosphate kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR), EGFR/JNK/SP-1, nitric oxide (NO)-signaling, and extracellular vesicles; 2) gene expression modulation via microRNAs (miR), in particular via miR-17-3p and miR-222; and 3) modulation of cardiac cellular metabolism and mitochondrial adaption. Understanding the cellular mechanisms, which generate an exercise-induced cardioprotective cellular phenotype with physiological hypertrophy and enhanced proliferational capacity may give rise to novel therapeutic targets. These may open up innovative strategies to preserve cardiac function after myocardial injury as well as in aged cardiac tissue.

scholarly journals Mip1, an MEKK2-Interacting Protein, Controls MEKK2 Dimerization and Activation

2005 ◽  
Vol 25 (14) ◽  
pp. 5955-5964 ◽  
Author(s):  
Jinke Cheng ◽  
Dongyu Zhang ◽  
Kihwan Kim ◽  
Yingxin Zhao ◽  
Yingming Zhao ◽  
...  
Keyword(s):  
Intracellular Signaling ◽  
Wide Spectrum ◽  
Gene Activation ◽  
Mitogen Activated Protein Kinase ◽  
Interacting Protein ◽  
Mapk Kinase ◽  
Mapk Cascades ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Molecular Aspects

ABSTRACT Mitogen-activated protein kinase (MAPK) cascades are central components of the intracellular signaling networks used by eukaryotic cells to respond to a wide spectrum of extracellular stimuli. An MAPK is activated by an MAPK kinase, which in turn is activated by an MAPK kinase kinase (MAP3K). However, little is known about the molecular aspects of the regulation and activation of large numbers of MAP3Ks that are crucial in relaying upstream receptor-mediated signals through the MAPK cascades to induce various physiological responses. In this study, we identified a novel MEKK2-interacting protein, Mip1, that regulates MEKK2 dimerization and activation by forming a complex with inactive and nonphosphorylated MEKK2. In particular, Mip1 prevented MEKK2 activation by blocking MEKK2 dimer formation, which in turn blocked JNKK2, c-Jun N-terminal kinase 1 (JNK1), extracellular signal-regulated kinase 5, and AP-1 reporter gene activation by MEKK2. Furthermore, we found that the endogenous Mip1-MEKK2 complex was dissociated transiently following epidermal growth factor stimulation. In contrast, the knockdown of Mip1 expression by siRNA augmented the MEKK2-mediated JNK and AP-1 reporter activation. Together, our data suggest a novel model for MEKK2 regulation and activation.

scholarly journals Zinc is a novel intracellular second messenger

2007 ◽  
Vol 177 (4) ◽  
pp. 637-645 ◽  
Author(s):  
Satoru Yamasaki ◽  
Kumiko Sakata-Sogawa ◽  
Aiko Hasegawa ◽  
Tomoyuki Suzuki ◽  
Koki Kabu ◽  
...  
Keyword(s):  
Intracellular Signaling ◽  
Calcium Influx ◽  
Second Messenger ◽  
Zinc Homeostasis ◽  
Mitogen Activated Protein Kinase ◽  
Kinase Activation ◽  
Extracellular Signal ◽  
Signaling Events ◽  
Mitogen Activated Protein ◽  
Extracellular Stimuli

Zinc is an essential trace element required for enzymatic activity and for maintaining the conformation of many transcription factors; thus, zinc homeostasis is tightly regulated. Although zinc affects several signaling molecules and may act as a neurotransmitter, it remains unknown whether zinc acts as an intracellular second messenger capable of transducing extracellular stimuli into intracellular signaling events. In this study, we report that the cross-linking of the high affinity immunoglobin E receptor (Fcε receptor I [FcεRI]) induced a release of free zinc from the perinuclear area, including the endoplasmic reticulum in mast cells, a phenomenon we call the zinc wave. The zinc wave was dependent on calcium influx and mitogen-activated protein kinase/extracellular signal-regulated kinase kinase activation. The results suggest that the zinc wave is involved in intracellular signaling events, at least in part by modulating the duration and strength of FcεRI-mediated signaling. Collectively, our findings indicate that zinc is a novel intracellular second messenger.

Extracellular signal–regulated protein kinase signaling pathway negatively regulates the phenotypic and functional maturation of monocyte-derived human dendritic cells

Blood ◽  
2001 ◽  
Vol 98 (7) ◽  
pp. 2175-2182 ◽  
Author(s):  
Amaya Puig-Kröger ◽  
Miguel Relloso ◽  
Oskar Fernández-Capetillo ◽  
Ana Zubiaga ◽  
Augusto Silva ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Protein Kinase ◽  
Intracellular Signaling ◽  
Mannose Receptor ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Functional Maturation ◽  
Extracellular Signal ◽  
Tnf Α ◽  
Mitogen Activated Protein

Dendritic cells (DC) are highly specialized antigen-presenting cells that on activation by inflammatory stimuli (eg, tumor necrosis factor α [TNF-α] and interleukin-1β [IL-1β]) or infectious agents (eg, lipopolysaccharide [LPS]), mature and migrate into lymphoid organs. During maturation, DC acquire the capacity to prime and polarize resting naive T lymphocytes. Maturation of monocyte-derived DC (MDDC) is inhibited by the p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580. This study found that in the presence of the mitogen-activated protein kinase kinase 1–extracellular signal-regulated kinase (ERK) inhibitors PD98059 or U0126, TNF-α– and LPS-induced phenotypic and functional maturation is enhanced. ERK pathway inhibitors increased expression of major histocompatibility complex and costimulatory molecules; loss of mannose-receptor–mediated endocytic activity; nuclear factor-κB DNA-binding activity; release of IL-12 p40; and allogeneic T-cell proliferation induced by LPS or TNF-α. Moreover, PD98059 and U0126 enhanced LPS-triggered production of IL-12 p70. In agreement with the effect of ERK inhibitors, maturation of MDDC was delayed in the presence of serum, an effect that was reversed by U0126. These results indicate that the ERK and p38 MAPK signaling pathways differentially regulate maturation of MDDC and suggest that their relative levels of activation might modulate the initial commitment of naive T-helper (Th) cells toward Th1 or Th2 subsets. The findings also suggest that maturation of MDDC might be pharmacologically modified by altering the relative levels of activation of both intracellular signaling routes.

scholarly journals Decreased Phosphorylated ERK 1/2 in Individuals with Autism

2019 ◽  
Author(s):  
Anthony Russo ◽  
Albert Mensah ◽  
Judith Bowman
Keyword(s):  
Intracellular Signaling ◽  
Mapk Pathway ◽  
Growth Factor Receptor ◽  
Autism Spectrum ◽  
Mitogen Activated Protein Kinase ◽  
Signaling Cascades ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Epidermal Growth ◽  
Spectrum Disorders

Autism spectrum disorders (ASDs) are complex, highly heritable neurodevelopmental disorders affecting ∼1 in 60-100 children. The extracellular signal-regulated kinases, ERK1 and ERK2, are central elements of one of the most prominent intracellular signaling cascades, the mitogen activated protein kinase (MAPK) pathway. They are genetically linked to ASDs and other syndromes typified by intellectual disability. In this study, we measured the concentration of phosphorylated (activated) ERK 1 and 2. We present evidence that ERK is decreased in individuals with autism, and that ERK levels are associated with decreased Epidermal Growth Factor Receptor (EGFR).

scholarly journals Molecular and cellular mechanisms underlying the antidepressant effects of ketamine enantiomers and its metabolites

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chun Yang ◽  
Jianjun Yang ◽  
Ailin Luo ◽  
Kenji Hashimoto
Keyword(s):  
Mammalian Target Of Rapamycin ◽  
Tyrosine Kinase Receptor ◽  
Treatment Resistant ◽  
Cellular Mechanisms ◽  
Extracellular Signal Regulated Kinase ◽  
Aspartate Receptor ◽  
Extracellular Signal ◽  
Animal Models Of Depression ◽  
Antidepressant Effects ◽  
Resistant Depression

Abstract Although the robust antidepressant effects of the N-methyl-d-aspartate receptor (NMDAR) antagonist ketamine in patients with treatment-resistant depression are beyond doubt, the precise molecular and cellular mechanisms underlying its antidepressant effects remain unknown. NMDAR inhibition and the subsequent α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) activation are suggested to play a role in the antidepressant effects of ketamine. Although (R)-ketamine is a less potent NMDAR antagonist than (S)-ketamine, (R)-ketamine has shown more marked and longer-lasting antidepressant-like effects than (S)-ketamine in several animal models of depression. Furthermore, non-ketamine NMDAR antagonists do not exhibit robust ketamine-like antidepressant effects in patients with depression. These findings suggest that mechanisms other than NMDAR inhibition play a key role in the antidepressant effects of ketamine. Duman’s group demonstrated that the activation of mammalian target of rapamycin complex 1 (mTORC1) in the medial prefrontal cortex is reportedly involved in the antidepressant effects of ketamine. However, we reported that mTORC1 serves a role in the antidepressant effects of (S)-ketamine, but not of (R)-ketamine, and that extracellular signal-regulated kinase possibly underlie the antidepressant effects of (R)-ketamine. Several lines of evidence have demonstrated that brain-derived neurotrophic factor (BDNF) and its receptor, tyrosine kinase receptor B (TrkB), are crucial in the antidepressant effects of ketamine and its two enantiomers, (R)-ketamine and (S)-ketamine, in rodents. In addition, (2R,6R)-hydroxynormetamine [a metabolite of (R)-ketamine] and (S)-norketamine [a metabolite of (S)-ketamine] have been shown to exhibit antidepressant-like effects on rodents through the BDNF–TrkB cascade. In this review, we discuss recent findings on the molecular and cellular mechanisms underlying the antidepressant effects of enantiomers of ketamine and its metabolites. It may be time to reconsider the hypothesis of NMDAR inhibition and the subsequent AMPAR activation in the antidepressant effects of ketamine.

scholarly journals Up-Regulation of Interleukin-8 by Novel Small Cytoplasmic Molecules of Nontypeable Haemophilus influenzae via p38 and Extracellular Signal-Regulated Kinase Pathways

2003 ◽  
Vol 71 (10) ◽  
pp. 5523-5530 ◽  
Author(s):  
Beinan Wang ◽  
P. Patrick Cleary ◽  
Haidong Xu ◽  
Jian-Dong Li
Keyword(s):  
Protein Kinase ◽  
Haemophilus Influenzae ◽  
Intracellular Signaling ◽  
Interleukin 8 ◽  
Mitogen Activated Protein Kinase ◽  
Akt Pathway ◽  
Chronic Obstructive ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT Nontypeable Haemophilus influenzae (NTHI) is an important etiological agent of otitis media (OM) and of exacerbated chronic obstructive pulmonary diseases (COPD). Inflammation is a hallmark of both diseases. Interleukin-8 (IL-8), one of the important inflammatory mediators, is induced by NTHI and may play a significant role in the pathogenesis of these diseases. Our studies demonstrated that a soluble cytoplasmic fraction (SCF) from NTHI induced much greater IL-8 expression by human epithelial cells than did NTHI lipooligosaccharides and envelope proteins. The IL-8-inducing activity was associated with molecules of ≤3 kDa from SCF and was peptidase and lipase sensitive, suggesting that small lipopeptides are responsible for the strong IL-8 induction. Moreover, multiple intracellular signaling pathways were activated in response to cytoplasmic molecules. The results indicated that the p38 mitogen-activated protein kinase (MAPK) and Src-dependent Raf-1-Mek1/2-extracellular signal-regulated kinase mitogen-activated protein kinase (ERK MAPK) pathways are required for NTHI-induced IL-8 production. In contrast, the phosphatidylinositol 3-kinase (PI3K)-Akt pathway did not affect IL-8 expression, although this pathway was concomitantly activated upon exposure to NTHI SCF. The PI3K-Akt pathway was also directly activated by IL-8 and significantly inhibited by an antagonist of IL-8 receptors during NTHI stimulation. These results indicated that the PI3K-Akt pathway is activated in response to IL-8 that is induced by NTHI and may lead to other important epithelial cell responses. This work provides insight into essential molecular and cellular events that may impact on the pathogenesis of OM and COPD and identifies rational targets for anti-inflammatory intervention.

scholarly journals Temporal Characteristics of Activation, Deactivation, and Restimulation of Signal Transduction following Depolarization in the Pheochromocytoma Cell Line PC12

2003 ◽  
Vol 23 (14) ◽  
pp. 4788-4795 ◽  
Author(s):  
Amir H. Nashat ◽  
Robert Langer
Keyword(s):  
Signal Transduction ◽  
Intracellular Signaling ◽  
Recovery Period ◽  
Transient Rise ◽  
Extracellular Signal ◽  
Element Binding Protein ◽  
Cyclic Amp Response Element ◽  
Chronic Depolarization ◽  
Second Period ◽  
Signaling Activity

ABSTRACT This study focuses on the transient and dynamic activation of intracellular signal transduction following different protocols of depolarization. During chronic depolarization, phosphorylation of extracellular signal-regulated kinases (ERKs) was observed to peak and subsequently fall to low levels within 10 min of depolarization. Short periods of depolarization, from 1 to 5 min in duration, also led to phosphorylation of ERK, and the rate of ERK dephosphorylation was not affected by the duration of depolarization. Phosphorylation of the cyclic AMP response element binding protein (CREB) also peaked as a result of chronic depolarization but decreased to intermediate levels that were maintained for more than 1 h. Pulsatile depolarization was explored as a means to circumvent the deactivation of intracellular signaling activity during chronic depolarization. Both ERK and CREB were rephosphorylated by a second period of depolarization that followed a recovery period of 10 min or more. The effects of the durations of depolarization and interpulse recovery on reactivation of ERK and CREB were characterized. Measurements of free cytoplasmic Ca2+ confirmed the transient rise in the intracellular calcium concentration ([Ca2+]i) during chronic depolarization and the pulsatile increase in [Ca2+]i that can be achieved with short periods of depolarization. This study characterizes the dynamic activities of signal transduction following depolarization. Electrical stimulation of neurons induces many cellular changes that unfold over time, and the influx of Ca2+ ions that mediate these events is transient. This study suggests that pulsatile activity may be a means of maintaining signaling activity over long periods of time.

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