scholarly journals The p38 MAPK Signaling Activation in Colorectal Cancer upon Therapeutic Treatments

2020 ◽  
Vol 21 (8) ◽  
pp. 2773 ◽  
Author(s):  
Angelina Pranteda ◽  
Valentina Piastra ◽  
Lorenzo Stramucci ◽  
Deborah Fratantonio ◽  
Gianluca Bossi
Keyword(s):  
Colorectal Carcinoma ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Mapk Signaling ◽  
Chemotherapeutic Agents ◽  
Mitogen Activated Protein Kinase ◽  
High Expectations ◽  
P38 Mapk Pathway ◽  
Mapk Inhibitors ◽  
Signaling Activation

Pharmacological treatment of colorectal carcinoma currently proceeds through the administration of a combination of different chemotherapeutic agents. In the case of rectal carcinoma, radiation therapy also represents a therapeutic strategy. In an attempt at translating much-needed new targeted therapy to the clinics, p38 mitogen activated protein kinase (MAPK) inhibitors have been tested in clinical trials involving colorectal carcinoma patients, especially in combination with chemotherapy; however, despite the high expectations raised by a clear involvement of the p38 MAPK pathway in the response to therapeutic treatments, poor results have been obtained so far. In this work, we review recent insights into the exact role of the p38 MAPK pathway in response to currently available therapies for colorectal carcinoma, depicting an intricate scenario in which the p38 MAPK node presents many opportunities, as well as many challenges, for its perspective exploitation for clinical purposes.

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

2011 ◽  
Vol 300 (1) ◽  
pp. E103-E110 ◽  
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.

scholarly journals BMI1 Drives Steroidogenesis Through Epigenetically Repressing the p38 MAPK Pathway

2021 ◽  
Vol 9 ◽  
Author(s):  
Jun Yu ◽  
Yibo Wu ◽  
Hong Li ◽  
Hui Zhou ◽  
Cong Shen ◽  
...  
Keyword(s):  
P38 Mapk ◽  
Leydig Cells ◽  
Mapk Pathway ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Epigenetic Mechanism ◽  
Knock Out ◽  
Functional Changes ◽  
Testosterone Production ◽  
P38 Mapk Pathway

Testosterone biosynthesis progressively decreases in aging males primarily as a result of functional changes to Leydig cells. Despite this, the mechanisms underlying steroidogenesis remain largely unclear. Using gene knock-out approaches, we and others have recently identified Bmi1 as an anti-aging gene. Herein, we investigate the role of BMI1 in steroidogenesis using mouse MLTC-1 and primary Leydig cells. We show that BMI1 can positively regulate testosterone production. Mechanistically, in addition to its known role in antioxidant activity, we also report that p38 mitogen-activated protein kinase (MAPK) signaling is activated, and testosterone levels reduced, in BMI1-deficient cells; however, the silencing of the p38 MAPK pathway restores testosterone production. Furthermore, we reveal that BMI1 directly binds to the promoter region of Map3k3, an upstream activator of p38, thereby modulating its chromatin status and repressing its expression. Consequently, this results in the inhibition of the p38 MAPK pathway and the promotion of steroidogenesis. Our study uncovered a novel epigenetic mechanism in steroidogenesis involving BMI1-mediated gene silencing and provides potential therapeutic targets for the treatment of hypogonadism.

scholarly journals Somatostatin stimulates intestinal NHE8 expression via p38 MAPK pathway

2011 ◽  
Vol 300 (2) ◽  
pp. C375-C382 ◽  
Author(s):  
Chunhui Wang ◽  
Hua Xu ◽  
Huacong Chen ◽  
Jing Li ◽  
Bo Zhang ◽  
...  
Keyword(s):  
P38 Mapk ◽  
Mapk Pathway ◽  
Somatostatin Receptor ◽  
Peptide Hormone ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Phosphorylation ◽  
P38 Mapk Pathway ◽  
Mitogen Activated Protein ◽  
D Cells ◽  
Human Intestinal Cells

Diarrhea is a common manifestation of gastrointestinal disorders. Diarrhea-induced losses of fluid and electrolyte could lead to dehydration and electrolyte imbalances, resulting in significant morbidity and mortality, especially in children living in developing countries. Somatostatin, a peptide hormone secreted by D-cells, plays an important role in regulating motility and intestinal Na+ absorption. Although octreotide, a somatostatin analog, is used to treat diarrhea, its mechanisms of action are unclear. Here we showed that octreotide increased brush-border membrane Na+/H+ exchanger 8 (NHE8) expression in the small intestine to the exclusion of other NHEs that participate in Na+ absorption. The same effect also occurred in human intestinal cells (Caco-2). We found that the increase of NHE8 expression by somatostatin required p38 mitogen-activated protein kinase (MAPK) activation. Furthermore, the somatostatin receptor SSTR2 antagonist CYN154806 could abolish somatostatin-induced NHE8 expression and p38 MAPK phosphorylation. Thus our data provided the first concrete evidence indicating that somatostatin stimulates intestinal Na+ absorption by increasing intestinal NHE8 expression through the SSTR2-p38 MAPK pathway.

scholarly journals The Expanding Role of p38 Mitogen-Activated Protein Kinase in Programmed Host Cell Death

2019 ◽  
Vol 12 ◽  
pp. 117863611986459 ◽  
Author(s):  
Jessica Gräb ◽  
Jan Rybniker
Keyword(s):  
Protein Kinase ◽  
Host Cell ◽  
P38 Mapk ◽  
Bacterial Infections ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Host Cell Apoptosis ◽  
Mitogen Activated Protein ◽  
P38 Mapk Inhibitors ◽  
Mapk Inhibitors

The p38 mitogen-activated protein kinase (MAPK) is involved in a multitude of essential cellular processes. The kinase is activated in response to environmental stresses, including bacterial infections and inflammation, to regulate the immune response of the host. However, recent studies have demonstrated that pathogens can manipulate p38 MAPK signaling for their own benefit to either prevent or induce host cell apoptosis. In addition, there is evidence demonstrating that p38 MAPK is a potent trigger of pathogen-induced necrosis driven by mitochondrial membrane disruption. Given the large number of p38 MAPK inhibitors that have been tested in clinical trials, these findings provide an opportunity to repurpose these drugs for improved control of infectious diseases.

scholarly journals Estrogen Enhances Matrix Synthesis in Nucleus Pulposus Cell through the Estrogen Receptor β-p38 MAPK Pathway

2016 ◽  
Vol 39 (6) ◽  
pp. 2216-2226 ◽  
Author(s):  
Pei Li ◽  
Yuan Xu ◽  
Yibo Gan ◽  
Liyuan Wang ◽  
Bin Ouyang ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Signaling Pathway ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
Matrix Synthesis ◽  
P38 Mapk Pathway ◽  
Collagen Ii

Background/Aims: Matrix homeostasis within the disc nucleus pulposus (NP) tissue is important for disc function. Increasing evidence indicates that sex hormone can influence the severity of disc degeneration. This study was aimed to study the role of 17β-estradiol (E2) in NP matrix synthesis and its underlying mechanism. Methods: Rat NP cells were cultured with (10-5, 10-7 and 10-9 M) or without (control) E2 for48 hours. The estrogen receptor (ER)-β antagonist PHTPP and ERβ agonist ERB 041 were used to investigate the role mediated by ERβ. The p38 MAPK inhibitor SB203580 was used to investigate the role of p38 MAPK signaling pathway. Gene and protein expression of SOX9, aggrecan and collagen II, glycosaminoglycan (GAG) content, and immunostaining assay for aggrecan and collagen II were analyzed to evaluate matrix production in rat NP cells. Results: E2 enhanced NP matrix synthesis in a concentration-dependent manner regarding gene and proetin expression of SOX9, aggrecan and collagen II, protein deposition of aggrecan and collagen II, and GAG content. Moreover, activation of p38 MAPK signaling pathway was increased with elevating E2 concentration. Further analysis indicated that ERB 041 and PHTPP could respectively enhance and suppress effects of E2 on matrix synthesis in NP cells, as well as activation of p38 MAPK pathway. Additionally, inhibition of p38 MAPK signaling pathway significantly abolished the effects of E2 on matrix synthesis. Conclusion: E2 can enhance matrix synthesis of NP cells and the ERβ/p38 MAPK pathway is involved in this regulatory process.

scholarly journals An adaptive signaling network in melanoma inflammatory niches confers tolerance to MAPK signaling inhibition

2017 ◽  
Vol 214 (6) ◽  
pp. 1691-1710 ◽  
Author(s):  
Helen L. Young ◽  
Emily J. Rowling ◽  
Mattia Bugatti ◽  
Emanuele Giurisato ◽  
Nadia Luheshi ◽  
...  
Keyword(s):  
Mapk Pathway ◽  
Acquired Resistance ◽  
Drug Tolerance ◽  
Mapk Signaling ◽  
Signaling Network ◽  
Mitogen Activated Protein Kinase ◽  
Cytokine Signaling ◽  
Adaptive Responses ◽  
Mapk Inhibitors

Mitogen-activated protein kinase (MAPK) pathway antagonists induce profound clinical responses in advanced cutaneous melanoma, but complete remissions are frustrated by the development of acquired resistance. Before resistance emerges, adaptive responses establish a mutation-independent drug tolerance. Antagonizing these adaptive responses could improve drug effects, thereby thwarting the emergence of acquired resistance. In this study, we reveal that inflammatory niches consisting of tumor-associated macrophages and fibroblasts contribute to treatment tolerance through a cytokine-signaling network that involves macrophage-derived IL-1β and fibroblast-derived CXCR2 ligands. Fibroblasts require IL-1β to produce CXCR2 ligands, and loss of host IL-1R signaling in vivo reduces melanoma growth. In tumors from patients on treatment, signaling from inflammatory niches is amplified in the presence of MAPK inhibitors. Signaling from inflammatory niches counteracts combined BRAF/MEK (MAPK/extracellular signal–regulated kinase kinase) inhibitor treatment, and consequently, inhibiting IL-1R or CXCR2 signaling in vivo enhanced the efficacy of MAPK inhibitors. We conclude that melanoma inflammatory niches adapt to and confer drug tolerance toward BRAF and MEK inhibitors early during treatment.

Rho proteins and the p38-MAPK pathway are important mediators for LPS-induced interleukin-8 expression in human endothelial cells

Blood ◽  
2000 ◽  
Vol 95 (10) ◽  
pp. 3044-3051 ◽  
Author(s):  
Stefan Hippenstiel ◽  
Saskia Soeth ◽  
Birgit Kellas ◽  
Oliver Fuhrmann ◽  
Joachim Seybold ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
P38 Mapk ◽  
Messenger Rna ◽  
Mapk Pathway ◽  
Active Form ◽  
Interleukin 8 ◽  
Mitogen Activated Protein Kinase ◽  
Protein Accumulation ◽  
Rho Proteins ◽  
P38 Mapk Pathway

Bacterial endotoxin (lipopolysaccharide, or LPS) has potent proinflammatory properties by acting on many cell types, including endothelial cells. Secretion of the CXC-chemokine interleukin-8 (IL-8) by LPS-activated endothelial cells contributes substantially to the inflammatory response. Using human umbilical vein endothelial cells (HUVECs), we analyzed the role of small GTP-binding Rho proteins and p38 mitogen-activated protein kinase (MAPK) for LPS-dependent IL-8 expression in endothelial cells. Specific inactivation of RhoA/Cdc42/Rac1 by Clostridium difficile toxin B-10463 (TcdB-10463) reduced LPS-induced tyrosine phosphorylation, nuclear factor (NF)-κB–dependent gene expression, IL-8 messenger RNA, and IL-8 protein accumulation but showed no effect on LPS-dependent p38 MAPK activation. Inhibition of p38 MAPK by SB 202190 also blocked LPS-induced NF-κB activation and IL-8 synthesis. Furthermore, selective activation of the p38 MAPK pathway by transient expression of a constitutively active form of MAPK kinase (MKK)6, the upstream activator of p38, was as effective as LPS with respect to IL-8 expression in HUVECs. In summary, our data suggest that LPS-induced NF-κB activation and IL-8 synthesis in HUVECs are regulated by both a Rho-dependent signaling pathway and the MKK6/p38 kinase cascade.

scholarly journals Posttranslational Regulation of Tristetraprolin Subcellular Localization and Protein Stability by p38 Mitogen-Activated Protein Kinase and Extracellular Signal-Regulated Kinase Pathways

2006 ◽  
Vol 26 (6) ◽  
pp. 2408-2418 ◽  
Author(s):  
Matthew Brook ◽  
Carmen R. Tchen ◽  
Tomas Santalucia ◽  
Joanne McIlrath ◽  
J. Simon C. Arthur ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Subcellular Localization ◽  
Protein Stability ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Extracellular Signal Regulated Kinase ◽  
P38 Mapk Pathway ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT The p38 mitogen-activated protein kinase (MAPK) signaling pathway, acting through the downstream kinase MK2, regulates the stability of many proinflammatory mRNAs that contain adenosine/uridine-rich elements (AREs). It is thought to do this by modulating the expression or activity of ARE-binding proteins that regulate mRNA turnover. MK2 phosphorylates the ARE-binding and mRNA-destabilizing protein tristetraprolin (TTP) at serines 52 and 178. Here we show that the p38 MAPK pathway regulates the subcellular localization and stability of TTP protein. A p38 MAPK inhibitor causes rapid dephosphorylation of TTP, relocalization from the cytoplasm to the nucleus, and degradation by the 20S/26S proteasome. Hence, continuous activity of the p38 MAPK pathway is required to maintain the phosphorylation status, cytoplasmic localization, and stability of TTP protein. The regulation of both subcellular localization and protein stability is dependent on MK2 and on the integrity of serines 52 and 178. Furthermore, the extracellular signal-regulated kinase (ERK) pathway synergizes with the p38 MAPK pathway to regulate both stability and localization of TTP. This effect is independent of kinases that are known to be synergistically activated by ERK and p38 MAPK. We present a model for the actions of TTP and the p38 MAPK pathway during distinct phases of the inflammatory response.

p38 Mitogen-Activated Protein Kinase and Hematologic Malignancies

2009 ◽  
Vol 133 (11) ◽  
pp. 1850-1856
Author(s):  
Yongdong Feng ◽  
Jianguo Wen ◽  
Chung-Che(Jeff) Chang
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Cell Types ◽  
Hematologic Malignancies ◽  
Mapk Signaling ◽  
Chemotherapeutic Agents ◽  
Mitogen Activated Protein Kinase ◽  
Cellular Functions ◽  
Downstream Effects ◽  
Mitogen Activated Protein

Abstract Context.—p38 mitogen-activated protein kinase (MAPK) signaling has been implicated in responses ranging from apoptosis to cell cycle, induction of expression of cytokine genes, and differentiation. This plethora of activators conveys the complexity of the p38 pathway. This complexity is further complicated by the observation that the downstream effects of p38 MAPK activation may be different depending on types of stimuli, cell types, and various p38 MAPK isoforms involved. Objective.—This review focuses on the recent advancement of the p38 MAPK isoforms as well as the roles of p38 MAPK in hematologic malignancies. Data Sources.—Review of pertinent published literature and work in our laboratory. Conclusions.—In some hematologic malignancies, activation of p38 plays a key role in promoting or inhibiting proliferation and also in increasing resistance to chemotherapeutic agents. The importance of different p38 isoforms in various cellular functions has been acknowledged recently. Further understanding of these isoforms will allow the design of more specific inhibitors to target particular isoforms to maximize the treatment effect and minimize the side effects for treating hematopoietic malignancies.

scholarly journals Stimulation of the p38 Mitogen-activated Protein Kinase Pathway in Neonatal Rat Ventricular Myocytes by the G Protein–coupled Receptor Agonists, Endothelin-1 and Phenylephrine: A Role in Cardiac Myocyte Hypertrophy?

1998 ◽  
Vol 142 (2) ◽  
pp. 523-535 ◽  
Author(s):  
Angela Clerk ◽  
Ashour Michael ◽  
Peter H. Sugden
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Cardiac Myocyte ◽  
Mapk Pathway ◽  
Morphological Changes ◽  
Mitogen Activated Protein Kinase ◽  
Neonatal Rat ◽  
Endothelin 1 ◽  
P38 Mapk Pathway ◽  
Cardiac Myocyte Hypertrophy

We examined the activation of the p38 mitogen-activated protein kinase (p38-MAPK) pathway by the G protein–coupled receptor agonists, endothelin-1 and phenylephrine in primary cultures of cardiac myocytes from neonatal rat hearts. Both agonists increased the phosphorylation (activation) of p38-MAPK by ∼12-fold. A p38-MAPK substrate, MAPK-activated protein kinase 2 (MAPKAPK2), was activated approximately fourfold and 10 μM SB203580, a p38-MAPK inhibitor, abolished this activation. Phosphorylation of the MAPKAPK2 substrate, heat shock protein 25/27, was also increased. Using selective inhibitors, activation of the p38-MAPK pathway by endothelin-1 was shown to involve protein kinase C but not Gi/Go nor the extracellularly responsive kinase (ERK) pathway. SB203580 failed to inhibit the morphological changes associated with cardiac myocyte hypertrophy induced by endothelin-1 or phenylephrine between 4 and 24 h. However, it decreased the myofibrillar organization and cell profile at 48 h. In contrast, inhibition of the ERK cascade with PD98059 prevented the increase in myofibrillar organization but not cell profile. These data are not consistent with a role for the p38-MAPK pathway in the immediate induction of the morphological changes of hypertrophy but suggest that it may be necessary over a longer period to maintain the response.

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