Abnormal arachidonic acid metabolic network may reduce sperm motility via P38 MAPK

Asthenozoospermia is a common cause of male infertility, the aetiology of which remains unclear in 50–60% of cases. The current study aimed to characterize metabolic alterations in asthenozoospermic seminal plasma and to explore the signalling pathways involved in sperm motility regulation. At first, high-performance liquid chromatography–electrospray ionization–tandem mass spectrometry was used to detect the targeted metabolic network of arachidonic acid (AA). Metabolomic multivariate data analysis showed significant distinction of AA metabolites between asthenozoospermic and healthy seminal plasma. AA as well as its lipoxygenase (LOX) and cytochrome P450 metabolites were found to be abnormally increased, while cyclooxygenase (COX) metabolites were complicatedly disturbed in asthenozoospermic volunteers compared with those in healthy ones. In vitro experiments and western blot analysis of sperm cells revealed a decrease in sperm motility and upregulation of sperm phosphor-P38 induced by AA. P38 inhibitor could increase AA-reduced sperm motility. Also, all the inhibitors of the three metabolic pathways of AA could block AA-induced P38 mitogen-activated protein kinase (MAPK) activation and further improve sperm motility. We report here for the first time that an abnormal AA metabolic network could reduce sperm motility via P38 MAPK activation through the LOX, cytochrome P450 and COX metabolic pathways, which might be an underlying pathomechanism of asthenozoospermia.

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Neurotoxicity of Lidocaine Involves Specific Activation of the p38 Mitogen-activated Protein Kinase, but Not Extracellular Signal–regulated or c-jun N-Terminal Kinases, and Is Mediated by Arachidonic Acid Metabolites

Anesthesiology ◽

10.1097/00000542-200611000-00025 ◽

2006 ◽

Vol 105 (5) ◽

pp. 1024-1033 ◽

Cited By ~ 34

Author(s):

Ingrid Haller ◽

Barbara Hausott ◽

Bettina Tomaselli ◽

Christian Keller ◽

Lars Klimaschewski ◽

...

Keyword(s):

Arachidonic Acid ◽

P38 Mapk ◽

Ganglion Cells ◽

Time Dependent ◽

Mitogen Activated Protein Kinase ◽

Extracellular Signal ◽

Mitogen Activated Protein ◽

P38 Mapk Inhibitors ◽

Mapk Inhibitors

Background Pharmacologic inhibition of the p38 mitogen-activated protein kinase (MAPK) leads to a reduction in lidocaine neurotoxicity in vitro and in vivo. The current study investigated in vitro the hypotheses that lidocaine neurotoxicity is specific for dorsal root ganglion cells of different size or phenotype, involves time-dependent and specific activation of the p38 MAPK, that p38 MAPK inhibitors are only effective if applied with local anesthetic, and that p38 MAPK activation triggers activation of lipoxygenase pathways. Methods The authors used primary sensory neuron cultures and pheochromocytoma cell line cultures to detect time-dependent activation of the p38 MAPK or related pathways such as extracellular signal-regulated kinases and c-jun N-terminal kinases. Cells were divided by size or by immunoreactivity for calcitonin gene-related peptide or isolectin B4, indicative of nociceptive phenotype. The authors also investigated whether arachidonic acid pathways represent a downstream effector of the p38 MAPK in local anesthetic-induced neurotoxicity. Results All types of dorsal root ganglion cells were subject to neurotoxic effects of lidocaine, which were mediated by specific activation of the p38 MAPK but not extracellular signal-regulated kinases or c-jun N-terminal kinases. Neuroprotective efficacy of p38 MAPK inhibitors declined significantly when administered more than 1 h after lidocaine exposure. Activation of p38 MAPK preceded activation of arachidonic acid pathways. Neurotoxicity of lidocaine, specific activation of p38 MAPK, and neuroprotective effects of a p38 MAPK inhibitor were further confirmed in pheochromocytoma cell line cultures. Conclusions Specific and time-dependent activation of the p38 MAPK is involved in lidocaine-induced neurotoxicity, most likely followed by activation of lipoxygenase pathways.

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A novel vasculo-angiogenic effect of cilostazol mediated by cross-talk between multiple signalling pathways including the ERK/p38 MAPK signalling transduction cascade

Clinical Science ◽

10.1042/cs20110432 ◽

2012 ◽

Vol 123 (3) ◽

pp. 147-159 ◽

Cited By ~ 15

Author(s):

Ting-Hsing Chao ◽

Shih-Ya Tseng ◽

Yi-Heng Li ◽

Ping-Yen Liu ◽

Chung-Lung Cho ◽

...

Keyword(s):

Protein Kinase ◽

P38 Mapk ◽

Umbilical Vein ◽

Tube Formation ◽

Mitogen Activated Protein Kinase ◽

Signalling Pathways ◽

No Production ◽

Angiogenic Effect

Cilostazol is an anti-platelet agent with vasodilatory activity that acts by increasing intracellular concentrations of cAMP. Recent reports have suggested that cilostazol may promote angiogenesis. In the present study, we have investigated the effect of cilostazol in promoting angiogenesis and vasculogenesis in a hindlimb ischaemia model and have also examined its potential mechanism of action in vitro and in vivo. We found that cilostazol treatment significantly increased colony formation by human early EPCs (endothelial progenitor cells) through a mechanism involving the activation of cAMP/PKA (protein kinase A), PI3K (phosphoinositide 3-kinase)/Akt/eNOS (endothelial NO synthase) and ERK (extracellular-signal-regulated kinase)/p38 MAPK (mitogen-activated protein kinase) signalling pathways. Cilostazol also enhanced proliferation, chemotaxis, NO production and vascular tube formation in HUVECs (human umbilical vein endothelial cells) through activation of multiple signalling pathways downstream of PI3K/Akt/eNOS. Cilostazol up-regulated VEGF (vascular endothelial growth factor)-A165 expression and secretion of VEGF-A in HUVECs through activation of the PI3K/Akt/eNOS pathway. In a mouse hindlimb ischaemia model, recovery of blood flow ratio (ipsilateral/contralateral) 14 days after surgery was significantly improved in cilostazol-treated mice (10 mg/kg of body weight) compared with vehicle-treated controls (0.63±0.07 and 0.43±0.05 respectively, P<0.05). Circulating CD34+ cells were also increased in cilostazol-treated mice (3614±670 compared with 2151±608 cells/ml, P<0.05). Expression of VEGF and phosphorylation of PI3K/Akt/eNOS and ERK/p38 MAPK in ischaemic muscles were significantly enhanced by cilostazol. Our data suggest that cilostazol produces a vasculo-angiogenic effect by up-regulating a broad signalling network that includes the ERK/p38 MAPK, VEGF-A165, PI3K/Akt/eNOS and cAMP/PKA pathways.

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Cross-talk between IRAK-4 and the NADPH oxidase1

Biochemical Journal ◽

10.1042/bj20061184 ◽

2007 ◽

Vol 403 (3) ◽

pp. 451-461 ◽

Cited By ~ 50

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.

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APPL1 mediates adiponectin-stimulated p38 MAPK activation by scaffolding the TAK1-MKK3-p38 MAPK pathway

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00427.2010 ◽

2011 ◽

Vol 300 (1) ◽

pp. E103-E110 ◽

Cited By ~ 59

Author(s):

Xiaoban Xin ◽

Lijun Zhou ◽

Caleb M. Reyes ◽

Feng Liu ◽

Lily Q. Dong

Keyword(s):

Protein Kinase ◽

P38 Mapk ◽

Mapk Pathway ◽

Adaptor Protein ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Scaffolding Protein ◽

Mapk Activation ◽

P38 Mapk Pathway ◽

Mitogen Activated Protein

The adaptor protein APPL1 mediates the stimulatory effect of adiponectin on p38 mitogen-activated protein kinase (MAPK) signaling, yet the underlying mechanism remains unclear. Here we show that, in C2C12 cells, overexpression or suppression of APPL1 enhanced or suppressed, respectively, adiponectin-stimulated p38 MAPK upstream kinase cascade, consisting of transforming growth factor-β-activated kinase 1 (TAK1) and mitogen-activated protein kinase kinase 3 (MKK3). In vitro affinity binding and coimmunoprecipitation experiments revealed that TAK1 and MKK3 bind to different regions of APPL1, suggesting that APPL1 functions as a scaffolding protein to facilitate adiponectin-stimulated p38 MAPK activation. Interestingly, suppressing APPL1 had no effect on TNFα-stimulated p38 MAPK phosphorylation in C2C12 myotubes, indicating that the stimulatory effect of APPL1 on p38 MAPK activation is selective. Taken together, our study demonstrated that the TAK1-MKK3 cascade mediates adiponectin signaling and uncovers a scaffolding role of APPL1 in regulating the TAK1-MKK3-p38 MAPK pathway, specifically in response to adiponectin stimulation.

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Arachidonic acid (AA) inhibits basolateral K channels in the cortical collecting duct (CCD) via cytochrome P450 (CYP) epoxygenase‐dependent metabolic pathways

The FASEB Journal ◽

10.1096/fasebj.22.1_supplement.1201.3 ◽

2008 ◽

Vol 22 (S1) ◽

Author(s):

Zhijian Wang ◽

Yuan Wei ◽

Wenhui Wang

Keyword(s):

Arachidonic Acid ◽

Cytochrome P450 ◽

Metabolic Pathways ◽

Collecting Duct ◽

Cortical Collecting Duct ◽

K Channels

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Acute p38 MAPK activation decreases force development in ventricular myocytes

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00365.2003 ◽

2003 ◽

Vol 285 (6) ◽

pp. H2578-H2586 ◽

Cited By ~ 25

Author(s):

Yi Chen ◽

Ravi Rajashree ◽

Qinghang Liu ◽

Polly Hofmann

Keyword(s):

Protein Kinase ◽

P38 Mapk ◽

Ventricular Myocytes ◽

Fold Increase ◽

Isometric Tension ◽

Mitogen Activated Protein Kinase ◽

Independent Manner ◽

Mapk Activation ◽

Force Development ◽

Sb 203580

Evidence suggests that p38 mitogen-activated protein kinase (MAPK) activation influences cardiac function on an acute basis. The characterization and mechanisms by which this occurs were investigated in the present study. Adult rat ventricular myocytes treated with 1 mM arsenite for 30 min had a 16-fold increase in p38 MAPK phosphorylation that was attenuated by SB-203580 (a p38 MAPK inhibitor). Extracellular signal-regulated protein kinase (ERK) and c-Jun NH2-terminal kinase (JNK) were also minimally activated, but this activation was not sensitive to SB-203580. In addition, arsenite caused a p38 MAPK-independent translocation/activation of protein phosphatase 2a (PP2a) and decrease in phosphorylation of myosin light chain 2 (LC2). Arsenite-p38 MAPK activation led to translocation of heat shock protein 27 but not αB-crystallin to the myofilaments. Using isolated cardiomyocytes, we determined that arsenite reduces isometric tension without a change in Ca2+ sensitivity of tension via p38 MAPK and lowers myofibrillar actomyosin Mg2+-ATPase activity in a p38 MAPK-independent manner. Thus arsenite induces a p38 MAPK-independent change in PP2a and LC2 that may account for the arsenite-dependent decrease in ATPase and a p38 MAPK-dependent modification of the myofilaments that decreases myocardial force development.

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Bakuchiol Suppresses Inflammatory Responses Via the Downregulation of the p38 MAPK/ERK Signaling Pathway

International Journal of Molecular Sciences ◽

10.3390/ijms20143574 ◽

2019 ◽

Vol 20 (14) ◽

pp. 3574 ◽

Cited By ~ 4

Author(s):

Hye-Sun Lim ◽

Yu Jin Kim ◽

Bu-Yeo Kim ◽

Soo-Jin Jeong

Keyword(s):

Mrna Expression ◽

P38 Mapk ◽

Inflammatory Responses ◽

Mitogen Activated Protein Kinase ◽

Enzyme Linked Immunosorbent Assay ◽

Mice Model ◽

Tnf Α ◽

Cox 2

The purpose of the present study was to evaluate the effects of bakuchiol on the inflammatory response and to identify the molecular mechanism of the inflammatory effects in a lipopolysaccharide (LPS)-stimulated BV-2 mouse microglial cell line and mice model. The production of prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) was measured by enzyme-linked immunosorbent assay. The mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α, and IL-6 was measured using reverse transcription–polymerase chain reaction analysis. Mitogen-activated protein kinase (MAPK) phosphorylation was determined by western blot analysis. In vitro experiments, bakuchiol significantly suppressed the production of PGE2 and IL-6 in LPS-stimulated BV-2 cells, without causing cytotoxicity. In parallel, bakuchiol significantly inhibited the LPS-stimulated expression of iNOS, COX-2, and IL-6 in BV-2 cells. However, bakuchiol had no effect on the LPS-stimulated production and mRNA expression of TNF-α or on LPS-stimulated c-Jun NH2-terminal kinase phosphorylation. In contrast, p38 MAPK and extracellular signal-regulated kinase (ERK) phosphorylation were inhibited by bakuchiol. In vivo experiments, Bakuchiol reduced microglial activation in the hippocampus and cortex tissue of LPS-injected mice. Bakuchiol significantly suppressed LPS-injected production of TNF-α and IL-6 in serum. These results indicate that the anti-neuroinflammatory effects of bakuchiol in activated microglia are mainly regulated by the inhibition of the p38 MAPK and ERK pathways. We suggest that bakuchiol may be beneficial for various neuroinflammatory diseases.

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A role for PKCε and MAP kinase in bradykinin-induced arachidonic acid release in rabbit CCD cells

AJP Renal Physiology ◽

10.1152/ajprenal.1998.274.4.f728 ◽

1998 ◽

Vol 274 (4) ◽

pp. F728-F735 ◽

Cited By ~ 7

Author(s):

Mark A. Lal ◽

Pierre R. Proulx ◽

Richard L. Hébert

Keyword(s):

Arachidonic Acid ◽

Protein Kinase ◽

Intracellular Signaling ◽

Collecting Duct ◽

Mitogen Activated Protein Kinase ◽

Cortical Collecting Duct ◽

Paracrine Factors ◽

Mapk Activation ◽

Rate Limiting Step ◽

Mitogen Activated Protein

Arachidonic acid (AA) release is the rate-limiting step in the production of prostaglandins, an important class of autocrine/paracrine factors that modulate collecting duct function. Previous results from this laboratory have established cytosolic phospholipase A2(cPLA2) as the enzyme responsible for bradykinin (BK)-stimulated AA mobilization in rabbit cortical collecting duct (RCCD) cells, and the present study pursues the intracellular signaling mechanisms responsible for its activation. Pretreatment of cells with Ro-31-8220, an inhibitor of protein kinase C (PKC), or PD-98059, an inhibitor of the mitogen-activated protein kinase (MAPK) cascade, resulted in a 50–60% reduction in BK-stimulated AA release. Incubation of RCCD cells with a combination of both Ro-31-8220 and PD-98059 did not achieve a greater inhibition of either BK-stimulated AA release or cPLA2 activity, possibly indicating that MAPK activation was dependent upon prior activation of PKC. This was supported by the observation that BK-induced MAPK activation could be reversed by either inhibitor. Additional experiments dealing with immunoblots for PKC isozymes revealed that RCCD cells express PKC species α, γ, ε, and ζ. Following BK stimulation, only PKCε translocated to the particulate fraction. Based on these results, it appears that PKC is activated and involved in the sequential activation of MAPK and cPLA2 following BK treatment. The results also suggest that PKCε may be the isozyme implicated in the process.

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Phosphorylation of Argonaute 2 at serine-387 facilitates its localization to processing bodies

Biochemical Journal ◽

10.1042/bj20080599 ◽

2008 ◽

Vol 413 (3) ◽

pp. 429-436 ◽

Cited By ~ 134

Author(s):

Yan Zeng ◽

Heidi Sankala ◽

Xiaoxiao Zhang ◽

Paul R. Graves

Keyword(s):

Protein Kinase ◽

P38 Mapk ◽

Kinase Inhibitor ◽

Mapk Pathway ◽

Phosphorylation Site ◽

Mitogen Activated Protein Kinase ◽

Processing Bodies ◽

Mitogen Activated Protein

Ago (Argonaute) proteins are essential effectors of RNA-mediated gene silencing. To explore potential regulatory mechanisms for Ago proteins, we examined the phosphorylation of human Ago2. We identified serine-387 as the major Ago2 phosphorylation site in vivo. Phosphorylation of Ago2 at serine-387 was significantly induced by treatment with sodium arsenite or anisomycin, and arsenite-induced phosphorylation was inhibited by a p38 MAPK (mitogen-activated protein kinase) inhibitor, but not by inhibitors of JNK (c-Jun N-terminal kinase) or MEK [MAPK/ERK (extracellular-signal-regulated kinase) kinase]. MAPKAPK2 (MAPK-activated protein kinase-2) phosphorylated bacterially expressed full-length human Ago2 at serine-387 in vitro, but not the S387A mutant. Finally, mutation of serine-387 to an alanine residue or treatment of cells with a p38 MAPK inhibitor reduced the localization of Ago2 to processing bodies. These results suggest a potential regulatory mechanism for RNA silencing acting through Ago2 serine-387 phosphorylation mediated by the p38 MAPK pathway.

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