Activation of ERK1/2 by protein kinase C-alpha in response to hydrogen peroxide-induced cell death in human gingival fibroblasts.
Hydrogen peroxide (H(2)O(2)) increases protein tyrosine phosphorylation of numerous proteins in human gingival fibroblasts (HGFs). Two main proteins, with an apparent molecular weight of 44 and 42kDa, were phosphorylated after hydrogen peroxide stimulation of the human gingival fibroblasts. Further analysis identified these two proteins as ERK1/2. Maximum phosphorylation was detected at 10min post-H(2)O(2) treatment. Pretreatment with an MEK inhibitor, PD98059, inhibited H(2)O(2)-stimulated ERK1/2 phosphorylation in a dose-dependent manner. Treatment with H(2)O(2) also induced phosphorylation of protein kinase C-alpha (PKCalpha). Staurosporine, a PKC inhibitor, blocked ERK1/2 phosphorylation induced by H(2)O(2). In addition, H(2)O(2)-induced cell death was prevented by PD98059, SB203580, and calphostin C, which are MEK, p38 and PKC inhibitors, respectively. These results suggest that H(2)O(2) leads to the phosphorylation and activation of ERK1/2 in a PKC-dependent manner. These findings demonstrate that the MAPK signaling pathway plays an active role in mediating the H(2)O(2)-induced decrease in HGF cell viability and ATP depletion.
Gutiérrez-Venegas
Gloria
G
Laboratorio de Bioquímica, División de Estudios de Posgrado e Investigación, Facultad de Odontología, Universidad Nacional Autónoma de México, Ciudad de México, D.F., Mexico. gloria@fo.odonto.unam.mx
Arreguín-Cano
Juan Antonio
JA
Arroyo-Cruz
Rita
R
Villeda-Navarro
Mónica
M
Méndez-Mejía
José Antonio
JA
D000255:Adenosine Triphosphate / Q000378:metabolism; D015153:Blotting, Western; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects*; D005419:Flavonoids / Q000494:pharmacology; D005881:Gingiva / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity*; D007150:Immunohistochemistry; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D016877:Oxidants / Q000633:toxicity*; D010766:Phosphorylation; D051571:Protein Kinase C-alpha / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D013890:Thiourea / Q000031:analogs & derivatives / Q000494:pharmacology; D014343:Trypan Blue; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D004791:Enzyme Inhibitors; D005419:Flavonoids; D016877:Oxidants; D000255:Adenosine Triphosphate; C038983:1,3-dimethylthiourea; D006861:Hydrogen Peroxide; D051571:Protein Kinase C-alpha; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; D013890:Thiourea; D014343:Trypan Blue; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one