scholarly journals The role of MAPK11/12/13/14 (p38 MAPK) protein in dopamine agonist-resistant prolactinomas

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shuman Wang ◽  
Aihua Wang ◽  
Yu Zhang ◽  
Kejing Zhu ◽  
Xiong Wang ◽  
...  
Keyword(s):  
Dopamine Agonist ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Inhibitory Effect ◽  
Resistance Rate ◽  
Gh3 Cells ◽  
Sirna Transfection

Abstract Background Prolactinoma is a functional pituitary adenoma that secretes excessive prolactin. Dopamine agonists (DAs) such as bromocriptine (BRC) are the first-line treatment for prolactinomas, but the resistance rate is increasing year by year, creating a clinical challenge. Therefore, it is urgent to explore the molecular mechanism of bromocriptine resistance in prolactinomas. Activation of the P38 MAPK pathway affects multidrug resistance in tumours. Our previous studies have demonstrated that inhibiting MAPK14 can suppress the occurrence of prolactinoma, but the role of MAPK11/12/13/14 (p38 MAPK) signalling in dopamine agonist-resistant prolactinomas is still unclear. Methods A prolactinoma rat model was established to determine the effect of bromocriptine on MAPK11/12/13/14 signalling. DA-resistant GH3 cells and DA-sensitive MMQ cells were used, and the role of MAPK11/12/13/14 in bromocriptine-resistant prolactinomas was preliminarily verified by western blot, RT-qPCR, ELISA, flow cytometry and CCK-8 experiments. The effects of MAPK11 or MAPK14 on bromocriptine-resistant prolactinomas were further verified by siRNA transfection experiments. Results Bromocriptine was used to treat rat prolactinoma by upregulating DRD2 expression and downregulating the expression level of MAPK11/12/13/14 in vivo experiments. The in vitro experiments showed that GH3 cells are resistant to bromocriptine and that MMQ cells are sensitive to bromocriptine. Bromocriptine could significantly reduce the expression of MAPK12 and MAPK13 in GH3 cells and MMQ cells. Bromocriptine could significantly reduce the expression of MAPK11, MAPK14, NF-κB p65 and Bcl2 in MMQ but had no effect on MAPK11, MAPK14, NF-κB p65 and Bcl2 in GH3 cells. In addition, knockdown of MAPK11 and MAPK14 in GH3 cells by siRNA transfection reversed the resistance of GH3 cells to bromocriptine, and haloperidol (HAL) blocked the inhibitory effect of bromocriptine on MAPK14, MAPK11, and PRL in MMQ cells. Our findings show that MAPK11 and MAPK14 proteins are involved in bromocriptine resistance in prolactinomas. Conclusion Bromocriptine reduces the expression of MAPK11/12/13/14 in prolactinomas, and MAPK11 and MAPK14 are involved in bromocriptine resistance in prolactinomas by regulating apoptosis. Reducing the expression of MAPK11 or MAPK14 can reverse bromocriptine resistance in prolactinomas.

scholarly journals Activity of the Pore-Forming Virulence Factor Listeriolysin O Is Reversibly Inhibited by Naturally Occurring S-Glutathionylation

2017 ◽  
Vol 85 (4) ◽  
Author(s):  
Jonathan L. Portman ◽  
Qiongying Huang ◽  
Michelle L. Reniere ◽  
Anthony T. Iavarone ◽  
Daniel A. Portnoy
Keyword(s):  
Protein Function ◽  
Inhibitory Effect ◽  
Cysteine Residue ◽  
Infection Model ◽  
Listeriolysin O ◽  
Content Type ◽  
Pore Forming Proteins

ABSTRACT Cholesterol-dependent cytolysins (CDCs) represent a family of homologous pore-forming proteins secreted by many Gram-positive bacterial pathogens. CDCs mediate membrane binding partly through a conserved C-terminal undecapeptide, which contains a single cysteine residue. While mutational changes to other residues in the undecapeptide typically have severe effects, mutation of the cysteine residue to alanine has minor effects on overall protein function. Thus, the role of this highly conserved reactive cysteine residue remains largely unknown. We report here that the CDC listeriolysin O (LLO), secreted by the facultative intracellular pathogen Listeria monocytogenes, was posttranslationally modified by S-glutathionylation at this conserved cysteine residue and that either endogenously synthesized or exogenously added glutathione was sufficient to form this modification. When recapitulated with purified protein in vitro, this modification completely ablated the activity of LLO, and this inhibitory effect was fully reversible by treatment with reducing agents. A cysteine-to-alanine mutation in LLO rendered the protein completely resistant to inactivation by S-glutathionylation, and a mutant expressing this mutation retained full hemolytic activity. A mutant strain of L. monocytogenes expressing the cysteine-to-alanine variant of LLO was able to infect and replicate within bone marrow-derived macrophages indistinguishably from the wild type in vitro, yet it was attenuated 4- to 6-fold in a competitive murine infection model in vivo. This study suggests that S-glutathionylation may represent a mechanism by which CDC-family proteins are posttranslationally modified and regulated and help explain an evolutionary pressure to retain the highly conserved undecapeptide cysteine.

Role of endothelial cells in regulating hemoglobin-induced changes in lymphatic pumping

1992 ◽  
Vol 263 (6) ◽  
pp. H1880-H1887 ◽  
Author(s):  
R. M. Elias ◽  
J. Eisenhoffer ◽  
M. G. Johnston
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Inhibitory Effect ◽  
Direct Inhibitory Effect ◽  
Induced Changes ◽  
Lymphatic Pumping ◽  
Pumping Activity

Studies with a sheep isolated duct preparation in vivo demonstrated that the route of administration of hemoglobin was important in demonstrating its inhibitory effect on lymphatic pumping. With autologous oxyhemoglobin administered intravenously (final plasma concentration 5 x 10(-5) M), pumping was not inhibited. However, the addition of oxyhemoglobin (5 x 10(-5) M) into the reservoir (lumen of the duct) resulted in > 95% inhibition of pumping. The extraluminal administration of oxyhemoglobin (10(-5) M) to bovine mesenteric lymphatics in vitro resulted in a 40% inhibition of pumping, whereas the introduction of oxyhemoglobin (10(-5) M) into the lumen of the vessels suppressed pumping 95%. In vessels mechanically denuded of endothelium, intraluminal oxyhemoglobin inhibited pumping 50%. These results suggested that oxyhemoglobin depressed pumping through an effect on both smooth muscle and endothelium. Once pumping was inhibited with oxyhemoglobin administration, stimulation of the duct with elevations in transmural pressure restored pumping activity when endothelial cells were present. However, in the absence of endothelium, pumping decreased with increases in distending pressures. We conclude that oxyhemoglobin has a direct inhibitory effect on lymphatic smooth muscle. The ability of oxyhemoglobin to alter the pressure range over which the lymph pump operates appears to be dependent on an intact endothelium.

Tougu Xiaotong capsules may inhibit p38 MAPK pathway-mediated inflammation: In vivo and in vitro verification

2020 ◽  
Vol 249 ◽  
pp. 112390 ◽  
Author(s):  
Xihai Li ◽  
Zhenli Zhang ◽  
Wenna Liang ◽  
Jianwei Zeng ◽  
Xiang Shao ◽  
...  
Keyword(s):  
P38 Mapk ◽  
Mapk Pathway ◽  
P38 Mapk Pathway

scholarly journals LINC01006 facilitates cell proliferation, migration and invasion in prostate cancer through targeting miR-34a-5p to up-regulate DAAM1

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Enhui Ma ◽  
Qianqian Wang ◽  
Jinhua Li ◽  
Xinqi Zhang ◽  
Zhenjia Guo ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostate Gland ◽  
Inhibitory Effect ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Protein Coding ◽  
Novel Target

Abstract Background Prostate cancer (PCa) is a kind of malignancy occurring in the prostate gland. Substantial researches have proved the major role of long noncoding RNAs (lncRNAs) in PCa. However, the role of long intergenic non-protein coding RNA 1006 (LINC01006) in PCa has not been investigated yet. Methods RT-qPCR was used to examine the expression levels of LINC01006 and its downstream targets. The function of LINC01006 in PCa was tested by in vitro and in vivo assays. With application of RNA pull down, RNA immunoprecipitation (RIP) and luciferase reporter assays, the interaction among LINC01006, miR-34a-5p and disheveled associated activator of morphogenesis 1 (DAAM1) were verified. Results LINC01006 expression presented high in PCa cell lines. LINC01006 silencing suppressed cell proliferative, migratory, invasive capacities while accelerated apoptotic rate. Besides, LINC01006 knockdown also suppressed tumor growth and metastasis in vivo. Furthermore, miR-34a-5p, a tumor suppressor in PCa, was sponged by LINC01006. Moreover, DAAM1 was targeted by miR-34a-5p and promoted PCa progression. More intriguingly, rescue assays suggested that the inhibitory effect of LINC01006 knockdown on PCa development was offset by DAAM1 overexpression. Conclusions LINC01006 promoted PCa progression by sponging miR-34a-5p to up-regulate DAAM1, providing a novel target for PCa therapy.

scholarly journals The protective role of microRNA-21 against coxsackievirus B3 infection through targeting the MAP2K3/P38 MAPK signaling pathway

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Feng He ◽  
Zonghui Xiao ◽  
Hailan Yao ◽  
Sen Li ◽  
Miao Feng ◽  
...  
Keyword(s):  
P38 Mapk ◽  
Cell Apoptosis ◽  
Specific Inhibitor ◽  
Inhibitory Effect ◽  
Mapk Signaling ◽  
Apoptosis Rate ◽  
Cvb3 Infection ◽  
Interfering Rna

Abstract Background The P38 mitogen-activated protein kinase (MAPK) pathway plays an essential role in CVB3-induced diseases. We previously demonstrated microRNA-21 has potential inhibitory effect on the MAP2K3 which locates upstream of P38 MAPK and was upregulated in mouse hearts upon CVB3 infection. However, the effect and underlying mechanism of miRNA-21 on CVB3 infection remain unclear. Methods We detected continuous changes of cellular miRNA-21 and P38 MAPK proteins expression profiling post CVB3 infection in vitro within 12 h. P38 MAPK signaling was inhibited by the specific inhibitor, small interfering RNA and miRNA-21 mimic in vitro, CVB3 replication, cell apoptosis rate and proliferation were detected. Viral load in the mice heart, cardiomyocyte apoptosis rate and histological of the heart were also detected in the mice model of viral myocarditis pretreated with miRNA-21-lentivirus. Results We observed significant upregulation of miRNA-21 expression followed by suppression of the MAP2K3/P38 MAPK signaling in CVB3-infected Hela cells. The inactivation of the MAP2K3/P38 MAPK signaling by P38 MAPK specific inhibitor, small interfering RNA against MAP2K3, or miRNA-21 overexpression significantly inhibited viral progeny release from CVB3-infected cells. Mechanistically, when compared with control miRNA, miRNA-21 showed no effect on capsid protein VP1 expression and viral load within host cells, while significantly reversing CVB3-induced caspase-3 activation and cell apoptosis rate, further promoting proliferation of infected cells, which indicates the inhibitory effect of miRNA-21 on CVB3 progeny release. In the in vivo study, when compared with control miRNA, miRNA-21 pretreatment remarkably inactivated the MAP2K3/P38 MAPK signaling in mice and protected them against CVB3 infection as evidenced by significantly alleviated cell apoptosis rate, reduced viral titers, necrosis in the heart as well as by remarkably prolonged survival time. Conclusions miRNA-21 were reverse correlated with P38 MAPK activation post CVB3 infection, miRNA-21 overexpression significantly inhibited viral progeny release and decreased myocytes apoptosis rate in vitro and in vivo, suggesting that miRNA-21 may serve as a potential therapeutic agent against CVB3 infection through targeting the MAP2K3/P38 MAPK signaling.

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

2008 ◽  
Vol 413 (3) ◽  
pp. 429-436 ◽  
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.

scholarly journals In vitro inhibition of porcine cytochrome P450 by 17β-estradiol and 17α-estradiol

2011 ◽  
Vol 4 (2) ◽  
pp. 78-84 ◽  
Author(s):  
Galia Zamaratskaia ◽  
Martin Rasmussen ◽  
Isabelle Herbin ◽  
Bo Ekstrand ◽  
Vladimir Zlabek
Keyword(s):  
Cytochrome P450 ◽  
Inhibitory Effect ◽  
17Β Estradiol ◽  
Cyp2e1 Activity ◽  
High Concentrations ◽  
Testicular Steroids ◽  
Sexually Mature

In vitro inhibition of porcine cytochrome P450 by 17β-estradiol and 17α-estradiol Sexually mature pigs are known to possess high concentrations of testicular steroids, which have been shown to change the activities of cytochrome P450 in vitro. The aim of the present study was to evaluate the regulation of CYP1A and CYP2E1 activity by the steroids dihydrotestosterone (DHT), 3β-androstenol, 17β-estradiol and 17α-estradiol. Catalytic activities of 7-ethoxyresorufin O-deethylase (EROD) and 7-methoxyresorufin O-demethylase (MROD) were used as markers of CYP1A activities, while p-nitrophenol hydroxylase (PNPH) was used as a marker of CYP2E1 activities. Of the steroids tested, only 17β-estradiol and 17α-estradiol inhibited EROD and MROD activities. This inhibition was observed when a steroid concentration of 100 μM was used, while lower concentrations showed no inhibitory effect. PNPH activities were inhibited only by 100 μM of 17β-estradiol. The significance of these results in vivo is unknown because inhibition was only found when concentrations of estrogens higher than physiological levels were used. Nevertheless, the results provided further evidence on the important role of estrogens in regulation of porcine cytochrome P450 activities.

scholarly journals Inhibiting IL-6 During Cytokine Storm in COVID-19: Potential Role of Natural Products

2021 ◽  
Author(s):  
Amirreza Nasirzadeh ◽  
Mohammad hosein Jafarzadeh Maivan ◽  
Javad Bazeli ◽  
Jafar Hajavi ◽  
Negar Yavarmanesh ◽  
...  
Keyword(s):  
Natural Products ◽  
Medicinal Plants ◽  
Inflammatory Responses ◽  
Survival Rates ◽  
Inhibitory Effect ◽  
Cytokine Storm ◽  
Regulatory Effects

Plant species with anti-inflammatory properties might play an essential role in combatting COVID-19 via reducing cytokine storms. We aimed to review the extant evidence of the potential therapeutic efficacy of natural products against cytokine storms by inhibiting interleukin-6 (IL-6) as a major pathological mediator. Data were collected following an electronic search in major databases (Pubmed, Scopus, Web of Science, Google Scholar) and also preprint articles on preprint and medRxiv servers by using a combination of relevant keywords. Seventeen active compounds and medicinal plants were found and reviewed in the present review. Results of both in-vivo and in-vitro experiments conducted on these compounds showed that Phillyrin, SMFM, Qiangzhi decoction, curcumin, Shen-Fu, Forsythia, and Alpha-Mangostin inhibit the production of IL-6. Andrographolide and Liu Shen Wan have an inhibitory effect on releasing this agent, while Ilex Asprella and Deoxy-11,12-didehydroandrographolide and naringin reduce the expression of IL-6. Theaflavin and Cholorogenic acid inhibit the secretion of IL-6, Xuebijing, and Chai-Hu-Gui-Zi-Gan-Jiang-Tang and Lipanpaidu prescription can reduce the serum level of IL-6. These agents also effectively improve infected lungs, increase survival rates, and minimize tissue damage. Medicinal plants and their phytochemical ingredients with down-regulatory effects on the expression of IL-6 have a potential influence on the inhibition of cytokine storms during viral infection caused by COVID-19. Therefore, phytochemicals could be regarded as promising candidates for managing cytokine storm inflammatory responses due to COVID-19 infection.

scholarly journals Evidence for Effective Inhibitory Actions on Hyperpolarization-Activated Cation Current Caused by Ganoderma Triterpenoids, the Main Active Constitutents of Ganoderma Spores

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4256 ◽  
Author(s):  
Wei-Ting Chang ◽  
Zi-Han Gao ◽  
Yi-Ching Lo ◽  
Sheng-Nan Wu
Keyword(s):  
Ionic Currents ◽  
Inhibitory Effect ◽  
Firing Frequency ◽  
Gh3 Cells ◽  
Heart Cells ◽  
Excitable Cells ◽  
Cell Current ◽  
Spontaneous Action

The triterpenoid fraction of Ganoderma (Ganoderma triterpenoids, GTs) has been increasingly demonstrated to provide effective antioxidant, neuroprotective or cardioprotective activities. However, whether GTs is capable of perturbing the transmembrane ionic currents existing in electrically excitable cells is not thoroughly investigated. In this study, an attempt was made to study whether GTs could modify hyperpolarization-activated cation currents (Ih) in pituitary tumor (GH3) cells and in HL-1 atrial cardiomyocytes. In whole-cell current recordings, the addition of GTs produced a dose-dependent reduction in the amplitude of Ih in GH3 cells with an IC50 value of 11.7 µg/mL, in combination with a lengthening in activation time constant of the current. GTs (10 µg/mL) also caused a conceivable shift in the steady-state activation curve of Ih along the voltage axis to a more negative potential by approximately 11 mV. Subsequent addition of neither 8-cyclopentyl-1,3-dipropylxanthine nor 8-(p-sulfophenyl)theophylline, still in the presence of GTs, could attenuate GTs-mediated inhibition of Ih. In current-clamp voltage recordings, GTs diminished the firing frequency of spontaneous action potentials in GH3 cells, and it also decreased the amplitude of sag potential in response to hyperpolarizing current stimuli. In murine HL-1 cardiomyocytes, the GTs addition also suppressed the amplitude of Ih effectively. In DPCPX (1 µM)-treated HL-1 cells, the inhibitory effect of GTs on Ih remained efficacious. Collectively, the inhibition of Ih caused by GTs is independent of its possible binding to adenosine receptors and it might have profound influence in electrical behaviors of different types of electrically excitable cells (e.g., pituitary and heart cells) if similar in vitro or in vivo findings occur.

scholarly journals The Role of Signaling Pathways of Inflammation and Oxidative Stress in Development of Senescence and Aging Phenotypes in Cardiovascular Disease

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1383 ◽  
Author(s):  
John Papaconstantinou
Keyword(s):  
Oxidative Stress ◽  
Cardiovascular Diseases ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Pharmacological Intervention ◽  
Mapk Activity ◽  
Chain Complexes ◽  
Stress Signals

The ASK1-signalosome→p38 MAPK and SAPK/JNK signaling networks promote senescence (in vitro) and aging (in vivo, animal models and human cohorts) in response to oxidative stress and inflammation. These networks contribute to the promotion of age-associated cardiovascular diseases of oxidative stress and inflammation. Furthermore, their inhibition delays the onset of these cardiovascular diseases as well as senescence and aging. In this review we focus on whether the (a) ASK1-signalosome, a major center of distribution of reactive oxygen species (ROS)-mediated stress signals, plays a role in the promotion of cardiovascular diseases of oxidative stress and inflammation; (b) The ASK1-signalosome links ROS signals generated by dysfunctional mitochondrial electron transport chain complexes to the p38 MAPK stress response pathway; (c) the pathway contributes to the sensitivity and vulnerability of aged tissues to diseases of oxidative stress; and (d) the importance of inhibitors of these pathways to the development of cardioprotection and pharmaceutical interventions. We propose that the ASK1-signalosome regulates the progression of cardiovascular diseases. The resultant attenuation of the physiological characteristics of cardiomyopathies and aging by inhibition of the ASK1-signalosome network lends support to this conclusion. Importantly the ROS-mediated activation of the ASK1-signalosome p38 MAPK pathway suggests it is a major center of dissemination of the ROS signals that promote senescence, aging and cardiovascular diseases. Pharmacological intervention is, therefore, feasible through the continued identification of potent, non-toxic small molecule inhibitors of either ASK1 or p38 MAPK activity. This is a fruitful future approach to the attenuation of physiological aspects of mammalian cardiomyopathies and aging.

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