The anti-inflammatory role of heme oxygenase-1 in lipopolysaccharide and cytokine-stimulated inducible nitric oxide synthase and nitric oxide production in human periodontal ligament cells.
BACKGROUND
Although heme oxygenase-1 (HO-1) is involved in anti-inflammation, the mechanisms of its activity in regulating periodontal inflammation are largely unclear. Therefore, the aim of this study is to investigate the anti-inflammatory properties of HO-1 in lipopolysaccharide (LPS)- and proinflammatory cytokine-stimulated inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production in human periodontal ligament (PDL) cells.


METHODS
PDL cells were treated with LPS plus a combination of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta in serum-free media for 1 day. The production of NO was evaluated using a Griess reagent kit. The expression of iNOS and HO-1 proteins and mRNAs was evaluated using Western blotting and reverse transcriptase-polymerase chain reaction, respectively.


RESULTS
Proinflammatory cytokines and LPS triggered iNOS and HO-1 expression and NO production in PDL cells. HO-1 inhibitor and HO-1 small interfering RNA (siRNA) attenuated the LPS- and cytokine-stimulated NO release and iNOS and HO-1 expression. Specific inhibitors of p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinases phosphatidylinositol 3-kinase (PI3K), nuclear factor-kappa B (NF-kappaB), and protein kinase C delta (PKC-delta) greatly reduced the levels of iNOS and HO-1 expression induced by LPS plus cytokines.


CONCLUSIONS
Collectively, these data suggested that HO-1 inhibition blocked LPS- and proinflammatory cytokine-stimulated iNOS expression and NO production in PDL cells via a mechanism that involves p38, ERK, PI3K, NF-kappaB, and PKC-delta. Thus, the regulation of HO-1 activity may be a therapeutic strategy for periodontal disease.
Kim
Young-Suk
YS
Department of Oral and Maxillofacial Pathology, College of Dentistry, Wonkwang University, Iksan, South Korea.
Pi
Sung-Hee
SH
Lee
Young-Man
YM
Lee
Sang-Im
SI
Kim
Eun-Cheol
EC
D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D002460:Cell Line; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects; D004790:Enzyme Induction; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors; D006419:Heme Oxygenase (Decyclizing) / Q000037:antagonists & inhibitors; D051547:Heme Oxygenase-1 / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology*; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008665:Metalloporphyrins / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D016328:NF-kappa B / Q000037:antagonists & inhibitors; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000187:drug effects*; D010513:Periodontal Ligament / Q000187:drug effects* / Q000201:enzymology; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051745:Protein Kinase C-delta / Q000037:antagonists & inhibitors; D011524:Protoporphyrins / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors
D000893:Anti-Inflammatory Agents; D004791:Enzyme Inhibitors; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D008665:Metalloporphyrins; D016328:NF-kappa B; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011524:Protoporphyrins; D034741:RNA, Small Interfering; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; C007095:cobaltiprotoporphyrin; C032628:tin protoporphyrin IX; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; D051745:Protein Kinase C-delta; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases