p38 and ERK1/2 MAPKs mediate the interplay of TNF-alpha and IL-10 in regulating oxidative stress and cardiac myocyte apoptosis.
It is known that TNF-alpha 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-alpha and IL-10 in regulating oxidative stress and cardiac myocyte apoptosis in Sprague-Dawley male rats. Isolated adult cardiac myocytes were exposed to TNF-alpha (10 ng/ml), IL-10 (10 ng/ml), and IL-10 + TNF-alpha (ratio 1) for 4 h. H(2)O(2) (100 microM) as a positive control and the antioxidant Trolox (20 micromol/l) were used to confirm the involvement of oxidative stress. H(2)O(2) treatment increased oxidative stress and apoptosis; TNF-alpha mimicked these effects. Exposure to TNF-alpha 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-alpha. The antioxidant Trolox modulated TNF-alpha-induced changes in Bax/Bcl-xl, cell injury, and MAPKs. Preexposure of cells to the p38 MAPK inhibitor SB-203580 prevented TNF-alpha-induced changes. Inhibition of the ERK pathway with PD-98059 attenuated the protective role of IL-10 against TNF-alpha-induced apoptosis. This study provides evidence in support of the essential role of p38 and ERK1/2 MAPKs in the interactive role of TNF-alpha and IL-10 in cardiac myocyte apoptosis.
Dhingra
Sanjiv
S
Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Center, 351 Tache Avenue, Winnipeg, Manitoba, Canada.
Sharma
Anita K
AK
Singla
Dinender K
DK
Singal
Pawan K
PK
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D002839:Chromans / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D016753:Interleukin-10 / Q000378:metabolism*; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D051020:bcl-X Protein / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D000975:Antioxidants; C494828:Bax protein, rat; C494813:Bcl2l1 protein, rat; D002839:Chromans; D005419:Flavonoids; D007093:Imidazoles; D047428:Protein Kinase Inhibitors; D011725:Pyridines; D014409:Tumor Necrosis Factor-alpha; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; D016753:Interleukin-10; D006861:Hydrogen Peroxide; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one