Involvement of mitogen-activated protein kinases and nuclear factor-kappa B activation in nitric oxide-induced interleukin-8 expression in human pulp cells.
OBJECTIVE
This study examined the effect of nitric oxide (NO) on interleukin-8 (IL-8) production and the involvement of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-kappaB) signaling pathways in primary cultured human pulp cells.


METHODS
IL-8 production was measured using enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. MAPK activation and IkappaB degradation and phosphorylation were determined by western blotting.


RESULTS
Sodium nitroprusside (SNP), an NO donor, has increased IL-8 secretion and mRNA expression in a dose- and time-dependent manner. SNP induced the phosphorylation of p38 MAPK and extracellular-regulated kinase (ERK), degradation and phosphorylation of IkappaB, and activation of NF-kappaB. Furthermore, inhibition of the ERK, p38, and NF-kappaB pathways blocked SNP-induced IL-8 secretion.


CONCLUSIONS
Human pulp cells showed NO-induced IL-8 expression via the MAPK and NF-kappaB pathways, which may play an important role in the inflammatory responses of pulp and periapical lesions.
Min
Kyung-San
KS
Department of Conservative Dentistry, College of Dentistry, Wonkwang University, Iksan, South Korea.
Kim
Hyun-Il
HI
Chang
Hoon-Sang
HS
Kim
Hyung-Ryong
HR
Pae
Hyun-Ock
HO
Chung
Hun-Taeg
HT
Hong
Seung-Heon
SH
Shin
Hong-In
HI
Hong
Chan-Ui
CU
Lee
Suk-Keun
SK
Kim
Eun-Cheol
EC
D015153:Blotting, Western; D002478:Cells, Cultured; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D016209:Interleukin-8 / Q000096:biosynthesis*; D020935:MAP Kinase Signaling System / Q000502:physiology*; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009569:Nitric Oxide / Q000494:pharmacology / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010766:Phosphorylation; D011671:Pulpitis / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
D020672:I-kappa B Proteins; D016209:Interleukin-8; D016328:NF-kappa B; D020030:Nitric Oxide Donors; D009599:Nitroprusside; D009569:Nitric Oxide; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases