Satoru Shindo

IL-6 Trans-Signaling Enhances CCL20 Production from IL-1β-Stimulated Human Periodontal Ligament Cells

CC chemokine ligand 20 (CCL20) plays a central role in the recruitment of CCR6-expressing cells, including Th17 cells which are related to bone resorption in periodontal lesions and thus in the development of periodontal disease. IL-6 is an important cytokine that is associated with the pathogenesis of periodontitis. However, the effect of IL-6 on CCL20 production is uncertain. The aim of this study was to examine whether IL-6 could modify CCL20 expression in human periodontal ligament cells (HPDLCs). HPDLCs expressed gp130 but did not express IL-6R on the surface of HPDLCs. So, IL-6 trans-signaling is important to recognize IL-6 by HPDLCs. IL-6/sIL-6R stimulation enhanced CCL20 production in IL-1β-stimulated HPDLCs. IL-6 produced from IL-1β-stimulated HPDLCs with sIL-6R could increase CCL20 production in HPDLCs with sIL-6R. Signal transducer and activator of transcription (STAT)3 activation was related to CCL20 production in IL-1β and IL-6/sIL-6R-stimulated HPDLCs. Our data suggests that HPDLCs, in response to IL-6, sIL-6R, and IL-1β, may shift chemokine production to that favoring CCR6-expressing cells recruitment in periodontal lesions.

(-)-Epigallocatechin-3-Gallate Inhibits CC Chemokine Ligand 11 Production in Human Gingival Fibroblasts

Background: CC chemokine ligand 11 (CCL11) is related to Th2 cells migration via CC chemokine receptor 3 (CCR3). Th2 cells are involved in the etiology of periodontal disease. However, how the infiltration of Th2 cells is controlled in periodontally diseased tissues is unknown. (-)-Epigallocatechin gallate (EGCG), the major catechin in green tea, has multiple beneficial effects, but the effects of EGCG on CCL11 production are uncertain. In this study, we investigated whether cytokines could induce CCL11 production in human gingival fibroblasts (HGFs). Moreover, we examined the effects of EGCG on CCL11 production in HGFs. Methods and Results: ELISA analysis disclosed that interleukin (IL)-4 synergistically enhanced CCL11 production in IL-1β or tumor necrosis factor (TNF)-α-stimulated HGFs. EGCG prevented IL-1β/ IL-4 or TNF-α/IL-4-mediated CCL11 production in a concentration dependent manner. CCL11 production in HGFs was positively regulated by p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK), and c-Jun N terminal kinase (JNK). Western blot analysis revealed that EGCG treatment prevented IL-1β/IL-4 or TNF-α/IL-4-induced ERK and JNK activation in HGFs. Conclusions: These data provide that CCL11 production in HGFs could be associated with Th2 cells infiltration in periodontal lesions. Moreover, EGCG is useful for periodontitis treatment to inhibit CCL11 production.

Calcitriol Suppressed Inflammatory Reactions in IL-1β-Stimulated Human Periodontal Ligament Cells

Vitamin D has important roles on control of calcium and phosphate levels in the body. However, the role of vitamin D on the pathogenesis of periodontal disease is still uncertain. Therefore, we examined the effect of the hormonal form of vitamin D, calcitriol, on inflammatory responses of human periodontal ligament cells (HPDLC). We detected vitamin D receptor expression in non-stimulated HPDLC. Calcitriol inhibited interleukin (IL)-6, IL-8, CC chemokine ligand (CCL) 20, CXC chemokine ligand (CXCL) 10, and matrix metalloproteinase (MMP)-3 release from IL-1β-stimulated HPDLC. Tissue inhibitor of metalloproteinase (TIMP)-1 production did not change by calcitriol. Moreover, we found c-jun N-terminal kinase (JNK) phosphorylation and IκB-α degradation in IL-1β-stimulated HPDLC were inhibited by calcitriol, and JNK and nuclear factor (NF)-κB inhibitors could decrease IL-6, IL-8, CCL20, CXCL10, and MMP-3 productions in IL-1β-treated HPDLC. These findings suggest that vitamin D could modulate inflammatory response in periodontal tissues.

Genipin Inhibits IL-1ß-Induced CCL20 and IL-6 Production from Human Periodontal Ligament Cells

Background/Aims: Genipin, the aglycon of geniposide found in gardenia fruit has long been considered for treatment of various diseases in traditional oriental medicine. Genipin has been used as a blue colorant in food industry. Genipin has recently been reported to have some pharmacological functions, such as antimicrobial, antitumor, and anti-inflammatory effects. The aim of this study was to examine whether genipin could modify CCL20 and IL-6, which are related to bone resorption in periodontal disease, expression in human periodontal ligament cells (HPDLCs). Methods: CCL20 and IL-6 productions from HPDLCs were determined by ELISA. Western blot analysis was used for the detection of signal transduction molecules expressions in HPDLCs. Results: Genipin prevented IL-1ß-mediated CCL20 and IL-6 production in HPDLCs. Moreover, genipin could suppress nuclear factor kappa B (NF-κB) p65, extracellular signalregulated kinase (ERK) and MAPK/ERK kinase (MEK) phosphorylations in IL-1ß-stimulated HPDLCs. NF-κB inhibitor and ERK inhibitor significantly inhibited IL-6 and CCL20 productions from IL-1ß-stimulated HPDLCs. Conclusions: These data provide a novel mechanism through which genipin could be used to provide direct benefits in periodontal disease to inhibit IL-6 and CCL20 productions in periodontal lesions.

TLR3 agonist enhances CC chemokine ligand 20 production in IL-1β-stimulated human gingival fibroblasts

Viruses are related to the etiology of periodontitis. However, the role of viruses on Th17 cells infiltration in periodontitis lesions is unknown. Therefore, we examined the effects of TLR3 ligand on CCL20, which is related to Th17 cells migration, production in human gingival fibroblasts (HGFs). Polyinosinic-polycytidylic acid (Poly I:C), which is a TLR3 agonist, stimulation could moderately induce CCL20 production in HGFs. Poly I:C synergistically enhanced CCL20 expression from IL-1β-stimulated HGFs. Inhibitors of p38 MAPK, extracellular signal-regulated kinase (ERK), c-Jun N terminal kinase (JNK), and NF-κB significantly inhibited CCL20 production in Poly I:C/IL-1β-stimulated HGFs. Western blot analysis disclosed phosphorylation of p38 MAPK, JNK, and IκB-α were enhanced in Poly I:C/IL-1β-treated HGFs. These data suggested that virus infection is related to Th17 cells migration in periodontitis lesion to induce CCL20 production in HGFs via TLR3. Therefore, our results indicated that virus might be important pathogen in periodontal disease.

IL-22 Enhances CCL20 Production in IL-1β-Stimulated Human Gingival Fibroblasts

CC chemokine ligand 20 (CCL20) is involved in the recruitment of Th17 cells and thus in the exacerbation of periodontal disease, but the effect of simultaneous interleukin (IL)-22 and IL-1β stimulation on CCL20 production in human gingival fibroblasts (HGFs) is uncertain. In this study, we investigated the mechanisms of IL-1β- and/or IL-22-induced CCL20 production in HGFs. A single stimulation of IL-22 could not induce CCL20 production. On the other hand, IL-22 could increase CCL20 production from IL-1β-stimulated HGFs in a dose-dependent manner. C-Jun N terminal kinase (JNK) and inhibitor of nuclear factor κB (IκB)-α phosphorylation were increased in IL-1β- and IL-22-stimulated HGFs. An inhibitor of nuclear factor (NF)-κB decreased IL-1β- and IL-22-induced CCL20 production, though an inhibitor of JNK did not modulate CCL20 production. These data suggest that IL-1β in cooperation with IL-22 could increase Th17 cell accumulation in periodontally diseased tissues to enhance CCL20 production in HGFs.

Tumor necrosis factor-like weak inducer of apoptosis increases CC chemokine ligand 20 production in interleukin 1β-stimulated human gingival fibroblasts.

CC chemokine ligand 20 (CCL20) is related to T-helper (Th)-17 cell migration, and Th17 cells play important roles in exacerbation in periodontal disease. However, the effect of tumor necrosis factor-like weak inducer of apoptosis (TWEAK) on CCL20 production is unknown. In this study, we examined the mechanisms of TWEAK in combination with interleukin (IL)-1β-induced CCL20 production in human gingival fibroblasts (HGFs). TWEAK alone did not induce CCL20 production in HGFs. However, TWEAK enhanced CCL20 expression from IL-1β-stimulated HGFs in a dose-dependent manner. Inhibitors of p38 mitogen-activated protein kinase, extracellular signal-regulated kinase (ERK), protein kinase B (Akt), and nuclear factor κB (NF-κB) significantly inhibited CCL20 production in TWEAK and IL-1β-stimulated HGFs. Western blot analysis revealed that phosphorylations of ERK, Akt, and inhibitor of NF-κB were enhanced in TWEAK and IL-1β-treated HGFs. These data suggest that TWEAK is positively related to Th17 cell migration in periodontally diseased tissues to enhance CCL20 production in IL-1β-stimulated HGFs.

Shikonin Inhibits Inflammatory Cytokine Production in Human Periodontal Ligament Cells

Shikonin, which is derived from Lithospermum erythrorhizon, a herb used in traditional medicine, has long been considered to be a useful treatment for various diseases in traditional oriental medicine. Shikonin has recently been reported to have several pharmacological properties, e.g., it has anti-microbial, anti-tumor, and anti-inflammatory effects. The aim of this study was to examine whether shikonin is able to influence the production of interleukin (IL)-6, IL-8, and/or chemokine C-C motif ligand (CCL)20, which contribute to the pathogenesis of periodontal disease, in human periodontal ligament cells (HPDLC). The production levels of IL-6, IL-8, and CCL20 in HPDLC were determined using an ELISA. Western blot analysis was used to detect nuclear factor kappa B (NF-κB) pathway activation in HPDLC. Shikonin prevented IL-1β- or tumor necrosis factor (TNF)-α-mediated IL-6, IL-8, and CCL20 production in HPDLC. Moreover, we found that shikonin suppressed the phosphorylation and degradation of inhibitor of kappa B-alpha (IκB-α) in IL-1β- or TNF-α-stimulated HPDLC. These findings suggest that shikonin could have direct beneficial effects against periodontal disease by reducing IL-6, IL-8, and CCL20 production in periodontal lesions.

Melatonin Inhibits CXCL10 and MMP-1 Production in IL-1β-Stimulated Human Periodontal Ligament Cells

Melatonin is a hormone that is mainly secreted by the pineal gland and exhibits a wide spectrum of activities, including antioxidant functions. Melatonin has been detected in gingival crevicular fluid. However, the role of melatonin in periodontal tissue is still uncertain. The aim of this study was to examine the effects of melatonin on inflammatory mediator expression in human periodontal ligament cells (HPDLC). Interleukin (IL)-1β induced CXC chemokine ligand (CXCL)10, matrix metalloproteinase (MMP)-1, and tissue inhibitors of metalloproteinase (TIMP)-1 production in HPDLC. Melatonin decreased CXCL10 and MMP-1 production and increased TIMP-1 production in IL-1β-stimulated HPDLC. Western blot analysis showed that melatonin inhibited p38 mitogen-activated protein kinase (MAPK) and c-jun N-terminal kinase (JNK) phosphorylation, and IkB-α degradation and phosphorylation in IL-1β-stimulated HPDLC. These results suggest that melatonin might inhibit Th1 cell migration by reducing CXCL10 production. Moreover, melatonin might inhibit soft tissue destruction by decreasing MMP-1 production in periodontal lesions.

IL-29 Enhances CXCL10 Production in TNF-α-stimulated Human Oral Epithelial Cells

ABSTRACT Interleukin-29 (IL-29) is a cytokine belonging to the Type III interferon family. It was recently detected in the gingival crevicular fluid of periodontitis patients. However, the role of IL-29 in the pathogenesis of periodontal disease remains unknown. The aim of this study was to examine the effects of IL-29 on C-X-C motif chemokine ligand 10 (CXCL10) production in human oral epithelial cells. We measured CXCL10 production in TR146 cells, which is a human oral epithelial cell line, using an enzyme-linked immunosorbent assay. We used a Western blot analysis to detect IL-29 receptor expression and the phosphorylation levels of signal transduction molecules, including p38 mitogen-activated protein kinases (MAPK), signal transducer and activator of transcription 3 (STAT3), and nuclear factor (NF)- κB p65, in the TR146 cells. The TR146 cells expressed the IL-29 receptor. IL-29 induced CXCL10 production in the TR146 cells. IL-29 significantly enhanced CXCL10 production in tumor necrosis factor (TNF)-α-stimulated TR146 cells. The p38 MAPK, STAT3, and NF-κB pathways were found to be related to the IL-29-induced enhancement of CXCL10 production in TNF-α-stimulated TR146 cells. IL-29 promotes T helper 1-cell accumulation in periodontal lesions by inducing CXCL10 production in oral epithelial cells.