Role of p38 MAPK in the Regulation of Apoptosis Signaling Induced by TNF-α in Differentiated PC12 Cells

Abstract Cytokines such as TNF α, IFN γ and others have been implicated in the pathogenesis of ineffective hematopoiesis in MDS and are thought to lead to the high rate of apoptosis in hematopoietic progenitors. The p38 Mitogen Activated Protein Kinase (MAPK) is an evolutionary conserved enzyme that is involved in many cellular processes including stress signaling. We have previously shown that the p38 MAP kinase is strongly activated by IFNs, TNF α, TGF β and other inhibitory cytokines in normal primary hematopoietic progenitors and plays an important role in the negative regulation of normal hematopoiesis. In the present study, we determined the role of the p38 MAPK in the pathogenesis of MDS evaluated its inhibition as a potential therapeutic strategy in this disease. p38 MAPK inhibition was achieved by the use of a novel p38 inhibitor - SD-282, a specific inhibitor of p38α MAP kinase. SD-282 performs very similarly in animal and cell models to a p38 inhibitor now in the clinic. We also transfected primary hematopoietic cells with flurescent labeled siRNAs against p38 and successfully downregulated the levels of the protein. Using these approaches, we demonstrate that pharmacological inhibition of the p38 MAPK can reverse the growth inhibitory effects of TNF α and IFN γ on erythroid and myeloid colony formation. This reversal of TNF α mediated inhibition correlates with significant reduction of apoptosis seen in human hematopoeitic progenitors pretreated with p38 inhibitor SD-282. Having established the importance of p38 MAPK in cytokine mediated inhibition of normal hematopoiesis, we performed colony forming assays with bone marrow CD34+ cells from 8 patients with MDS in the presence of either pharmacologic or siRNA based inhibitors of p38. All patients had refractory cytopenias with multilineage dysplasia. Our data indicates that SD-282 treatment strongly enhances both erythroid and myeloid colony formation in MDS CD34+ bone marrow cells in vitro. This increase was not observed when these progenitors were grown in the presence of negative controls - SB 202474 and the MEK inhibitor PD 98059. Similarly, an increase in hematopoietic colony formation, though of a lesser magnitude was seen when MDS bone marrow progenitors were transfected with siRNAs against p38 MAPK. To further determine the role of cytokines in the pathogenesis of MDS, we also used bone marrow derived sera from the same MDS patients. Our studies show exposure to patient derived sera led to the phosphorylation/activation of p38 MAPK in normal hematopoietic progenitors when compared to sera from healthy volunteers. Our studies also demonstrate that bone marrow derived sera from MDS patients can inhibit erythroid and myeloid colony formation of normal hematopoietic progenitors. This inhibition can be reversed by blocking p38 MAPK using SD-282, other p38 inhibitors and siRNAs. This finding confirms the role of marrow cytokine /serum factors in the ineffective hematopoiesis seen in MDS and suggests the importance of p38 MAPK activation in this phenomenon. Thus our studies show the p38 MAPK may be a common effector of inhibitory cytokine signaling in normal and MDS hematopoietic cells. These results provide a strong rationale for using p38 inhibition as a novel treatment strategy for MDS. Supported by Harris Methodist Foundation Grant, VISN-17 New Investigator Grant and VA Research Corp Grant to AV.

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Protective role of Bcl-2 on β-amyloid-induced cell death of differentiated PC12 cells: reduction of NF-κB and p38 MAP kinase activation

Neuroscience Research ◽

10.1016/j.neures.2004.01.010 ◽

2004 ◽

Vol 49 (1) ◽

pp. 69-80 ◽

Cited By ~ 47

Author(s):

Youn Sook Song ◽

Hye Ji Park ◽

Soo Yeon Kim ◽

Seung Ho Lee ◽

Hwan Soo Yoo ◽

...

Keyword(s):

Cell Death ◽

Map Kinase ◽

Pc12 Cells ◽

Protective Role ◽

P38 Map Kinase ◽

Kinase Activation ◽

Differentiated Pc12 Cells ◽

Β Amyloid

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Role of Apoptosis Signal-Regulating Kinase in Regulation of the c-Jun N-Terminal Kinase Pathway and Apoptosis in Sympathetic Neurons

Molecular and Cellular Biology ◽

10.1128/mcb.20.1.196-204.2000 ◽

2000 ◽

Vol 20 (1) ◽

pp. 196-204 ◽

Cited By ~ 121

Author(s):

Takashi Kanamoto ◽

Monica Mota ◽

Kohsuke Takeda ◽

Lee L. Rubin ◽

Kohei Miyazono ◽

...

Keyword(s):

Map Kinase ◽

Pc12 Cells ◽

Neuronal Apoptosis ◽

Sympathetic Neurons ◽

Active Form ◽

P38 Map Kinase ◽

Differentiated Pc12 Cells ◽

Mitogen Activated Protein ◽

Induced Apoptosis

ABSTRACT We have previously shown that nerve growth factor (NGF) withdrawal-induced death requires the activity of the small GTP-binding protein Cdc42 and that overexpression of an active form of Cdc42 is sufficient to mediate neuronal apoptosis via activation of the c-Jun pathway. Recently, a new mitogen-activated protein (MAP) kinase kinase kinase, apoptosis signal-regulating kinase 1 (ASK1) which activates both the c-Jun N-terminal kinase (JNK) and p38 MAP kinase pathways and plays pivotal roles in tumor necrosis factor- and Fas-induced apoptosis, has been identified. Therefore, we investigated the role of ASK1 in neuronal apoptosis by using rat pheochromocytoma (PC12) neuronal cells and primary rat sympathetic neurons (SCGs). Overexpression of ASK1-ΔN, a constitutively active mutant of ASK1, activated JNK and induced apoptosis in differentiated PC12 cells and SCG neurons. Moreover, in differentiated PC12 cells, NGF withdrawal induced a four- to fivefold increase in the activity of endogenous ASK1. Finally, expression of a kinase-inactive ASK1 significantly blocked both NGF withdrawal- and Cdc42-induced death and activation of c-jun. Taken together, these results demonstrate that ASK1 is a crucial element of NGF withdrawal-induced activation of the Cdc42–c-Jun pathway and neuronal apoptosis.

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p38 MAP kinase inhibition ameliorates cisplatin nephrotoxicity in mice

AJP Renal Physiology ◽

10.1152/ajprenal.00401.2004 ◽

2005 ◽

Vol 289 (1) ◽

pp. F166-F174 ◽

Cited By ~ 187

Author(s):

Ganesan Ramesh ◽

W. Brian Reeves

Keyword(s):

Renal Dysfunction ◽

P38 Mapk ◽

Renal Injury ◽

Acute Renal Injury ◽

Mapk Activation ◽

Mapk Activity ◽

Tnf Α

Cisplatin is an important chemotherapeutic agent but can cause acute renal injury. Part of this acute renal injury is mediated through tumor necrosis factor-α (TNF-α). The pathway through which cisplatin mediates the production of TNF-α and injury is not known. Cisplatin activates p38 MAPK and induces apoptosis in cancer cells. p38 MAPK activation leads to increased production of TNF-α in ischemic injury and in macrophages. However, little is known concerning the role of p38 MAPK in cisplatin-induced renal injury. Therefore, we examined the effect of cisplatin on p38 MAPK activity and the role of p38 MAPK in mediating cisplatin-induced TNF-α production and renal injury. In vitro, cisplatin caused a dose-dependent activation of p38 MAPK in proximal tubule cells. Inhibition of p38 MAPK activation led to inhibition of TNF-α production. In vivo, mice treated with a single dose of cisplatin (20 mg/kg body wt) developed severe renal dysfunction at 72 h [blood urea nitrogen (BUN): 154 ± 34 mg/dl, creatinine: 1.4 ± 0.4 mg/dl], which was accompanied by an increase in kidney p38 MAPK activity and an increase in infiltrating leukocytes. However, animals treated with the p38 MAPK inhibitor SKF-86002 along with cisplatin showed less renal dysfunction (BUN: 55 ± 14 mg/dl, creatinine: 0.3 ± 0.02 mg/dl, P < 0.05), less severe histological damage, and fewer leukocytes compared with cisplatin+vehicle-treated animals. Serum levels of TNF-α, sTNFRI, and sTNFRII also increased significantly in cisplatin-treated mice compared with SKF-86002-treated mice ( P < 0.05). Kidney mRNA levels of TNF-α were significantly increased in cisplatin-treated mice compared with either SKF-86002- or saline-treated animals. The hydroxyl radical scavenger DMTU (100 mg·kg body wt−1·day−1) prevented the activation of p38 MAPK by cisplatin both in vitro and in vivo. DMTU also completely prevented cisplatin-induced renal injury (BUN: 140 ± 27 vs. 22 ± 2 mg/dl, P < 0.005) and the increase in serum TNF-α (33 ± 7 vs. 4 ± 2 pg/ml, P < 0.005) and kidney TNF-α mRNA in vivo. We conclude that hydroxyl radicals, either directly or indirectly, activate p38 MAPK and that p38 MAPK plays an important role in mediating cisplatin-induced acute renal injury and inflammation, perhaps through production of TNF-α.

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The Pivotal Role of Intracellular Calcium in Oxaliplatin-Induced Inhibition of Neurite Outgrowth but Not Cell Death in Differentiated PC12 Cells

Chemical Research in Toxicology ◽

10.1021/tx200160g ◽

2011 ◽

Vol 24 (11) ◽

pp. 1845-1852 ◽

Cited By ~ 24

Author(s):

Miki Takeshita ◽

Yoshiko Banno ◽

Mitsuhiro Nakamura ◽

Mayuko Otsuka ◽

Hitomi Teramachi ◽

...

Keyword(s):

Cell Death ◽

Intracellular Calcium ◽

Neurite Outgrowth ◽

Pc12 Cells ◽

Pivotal Role ◽

Differentiated Pc12 Cells

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p38 and ERK1/2 MAPKs mediate the interplay of TNF-α and IL-10 in regulating oxidative stress and cardiac myocyte apoptosis

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00919.2007 ◽

2007 ◽

Vol 293 (6) ◽

pp. H3524-H3531 ◽

Cited By ~ 85

Author(s):

Sanjiv Dhingra ◽

Anita K. Sharma ◽

Dinender K. Singla ◽

Pawan K. Singal

Keyword(s):

Oxidative Stress ◽

P38 Mapk ◽

Cardiac Myocyte ◽

Cell Injury ◽

Male Rats ◽

Tnf Α ◽

Myocyte Apoptosis ◽

Cardiac Myocyte Apoptosis ◽

Induced Changes

It is known that TNF-α increases the production of ROS and decreases antioxidant enzymes, resulting in an increase in oxidative stress. IL-10 appears to modulate these effects. The present study investigated the role of p38 and ERK1/2 MAPKs in mediating the interplay of TNF-α and IL-10 in regulating oxidative stress and cardiac myocyte apoptosis in Sprague-Dawley male rats. Isolated adult cardiac myocytes were exposed to TNF-α (10 ng/ml), IL-10 (10 ng/ml), and IL-10 + TNF-α ( ratio 1) for 4 h. H2O2(100 μM) as a positive control and the antioxidant Trolox (20 μmol/l) were used to confirm the involvement of oxidative stress. H2O2treatment increased oxidative stress and apoptosis; TNF-α mimicked these effects. Exposure to TNF-α significantly increased ROS production, caused cell injury, and increased the number of apoptotic cells and Bax-to-Bcl-xl ratio. This change was associated with an increase in the phospho-p38 MAPK-to-total p38 MAPK ratio and a decrease in the phospho-ERK1/2-to-total ERK1/2 ratio. IL-10 treatment by itself had no effect on these parameters, but it prevented the above-listed changes caused by TNF-α. The antioxidant Trolox modulated TNF-α-induced changes in Bax/Bcl-xl, cell injury, and MAPKs. Preexposure of cells to the p38 MAPK inhibitor SB-203580 prevented TNF-α-induced changes. Inhibition of the ERK pathway with PD-98059 attenuated the protective role of IL-10 against TNF-α-induced apoptosis. This study provides evidence in support of the essential role of p38 and ERK1/2 MAPKs in the interactive role of TNF-α and IL-10 in cardiac myocyte apoptosis.

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