Pulp fibroblasts express various pro-inflammatory mediators leading to marked infiltration of inflammatory cells in the progression of pulpitis. We hypothesized that pulp fibroblasts play roles in the recognition of invaded caries-related bacteria and the subsequent innate immune responses. We found clear expressions of TLR2, NOD1, and NOD2 and a faint expression of TLR4 in human dental pulp fibroblasts (HDPF) by RT-PCR and flow cytometry. We also observed that various pro-inflammatory mediators, including cytokines, chemokines, adhesion molecules, prostaglandin E(2) and its key enzyme COX-2, not iNOS or caspase-1, were markedly up-regulated by stimulation with these TLR and NOD agonists. More over, the NOD2 agonist acted synergistically with the TLR2, not the TLR4, agonist to stimulate the production of pro-inflammatory mediators in HDPF. These findings indicate that TLR2, TLR4, NOD2, and NOD1 in HDPF are functional receptors, and NOD2 is a modulator of signals transmitted through TLR2 in pulpal immune responses, leading to progressive pulpitis.

No abstract

IDO induction can deplete l-tryptophan in target cells, an effect partially responsible for the antimicrobial activities and antiallogeneic T cell responses of IFN-γ in human macrophages, dendritic cells, and bone marrow cells. l-Tryptophan depletion and NO production are both known to have an antimicrobial effect in macrophages, and the interaction of these two mechanisms is unclear. In this study we found that IDO activity was inhibited by the peroxynitrite generator, 3-(4-morpholinyl)sydnonimine, in PMA-differentiated cytokine-induced THP-1 (acute monocytic leukemia) cells and IFN-γ-stimulated PBMCs, whereas IDO protein expression was unaffected compared with that in untreated cells. Nitrotyrosine was detected in immunoprecipitated (IP)-IDO from PMA-differentiated cytokine-induced THP-1 cells treated with 3-(4-morpholinyl)sydnonimine, but not from untreated cells. Treatment of IP-IDO and recombinant IDO (rIDO) with peroxynitrite significantly decreased enzyme activity. Nitrotyrosine was detected in both peroxynitrite-treated IP-IDO and rIDO, but not in either untreated IP-IDO or rIDO. Peptide analysis by liquid chromatography/electrospray ionization and tandem mass spectrometry demonstrated that Tyr15, Tyr345, and Tyr353 in rIDO were nitrated by peroxynitrite. The levels of Tyr nitration and the inhibitory effect of peroxynitrite on IDO activity were significantly reduced in the Tyr15-to-Phe mutant. These results indicate that IDO is nitrated and inactivated by peroxynitrite and that nitration of Tyr15 in IDO protein is the most important factor in the inactivation of IDO.

n arterial thrombus formation, the interaction of adenosine diphosphate (ADP) with its receptor P2Y12 plays an important role in platelet activation and its maintenance. [1][2][3][4] Dual antiplatelet therapy with aspirin and thienopyridine derivative is the standard therapy for the prevention of stent thrombosis in patients after percutaneous coronary intervention (PCI). [5][6][7][8] Ticlopidine, a 1st-generation P2Y12 ADP receptor antagonist, has been reported to have a relative high rate of side-effects. 9 Clopidogrel, a 2nd-generation P2Y12 ADP receptor antagonist, has been demonstrated to reduce the risk of cardiovascular events in patients with prior vascular diseases, 10,11 and is widely used for secondary prevention in patients with coronary artery disease. However, it is well known that clopidogrel exerts little antiplatelet effect in a certain proportion of patients, a phenomenon termed "clopidogrel resistance". 12-15 Importantly, cardiovascular risk is elevated after coronary stent implantation in patients with clopidogrel resistance. 16 Clopidogrel is a prodrug that requires two-step biotransformation processes mediated mainly by 2 cytochrome p450 enzymes (CYP), CYP2C19 and CYP3A4. 17,18 Two major single nucleotide polymorphisms (SNPs) of CYP2C19 are known to make the enzyme activity non-functional. 19,20 One is CYP2C19*2, which is the mutation of guanine to adenine at position 681 in exon 5, causing a splicing defect, 19 and the other is CYP2C19*3, which is the mutation of guanine to adenine at position 636 in exon 4, forming a stop codon. 20 The frequency of the CYP2C19*2 or *3 mutation varies among races. The frequency of CYP2C19*2 in Asians is higher (30%) than in Western people (~15%), whereas the CYP2C19*3 allele has been reported as frequent in Asians (~5%) and rare in Caucasians (0.04%). 21 Results of a recent study of healthy volunteer subjects showed that CYP2C19 polymorphisms are associated with a weaker antiplatelet response to clopidogrel. 22 Furthermore, the plasma concentration of the active metabolite of clopidogrel is affected by CYP2C19 genotype. 23 However, to our knowledge no study has evaluated the effect of CYP2C19 polymorphisms on the antiplatelet effect of clopidogrel in actual clinical patients with cardiovascular risks on aspirin therapy. The SNP of CYP3A4 (IVS10 +12G>A) has been reported to enhance the antiplatelet effect of clopidogrel, 24 and the SNP of P2Y12 (T744C) has been reported to reduce the antiplatelet effect of clopidogrel when it coexists with CYP2C19 SNPs. 25 We recently systematically evaluated the antiplatelet effect of clopidogrel during low-dose aspirin therapy in 30 Japanese patients scheduled for PCI, and reported a wide inter-individual variation in the antiplatelet effect of clopidogrel, with 4 cases (14%) being classified as non-responders. 26 Comparison of our data with results from a similar study performed in the US 27 also showed that the effectiveness of Background: The P2Y12 adenosine diphosphate (ADP) receptor blocker, clopidogrel, an essential...

Aim:Obstructive sleep apnea (OSA) is a risk factor for cardiovascular diseases. Platelets play key roles in the development of atherothrombosis. Several studies assessing platelet activation in patients with OSA have been published; however, there have been only a few studies with a small number of patients with OSA investigating platelet aggregability, which evaluates platelet aggregation more directly than the platelet activation status. We aimed to investigate the effects of OSA and nasal continuous positive airway pressure (nCPAP) therapy, a well-established treatment for OSA, on platelet aggregability. Methods and Results: We examined 124 consecutive patients with snoring in whom the 3% oxygen desaturation index (3%ODI), a severity marker of OSA, and ADP-and collagen-induced platelet aggregability measured with the optical aggregometer were analyzed. ADP-induced platelet aggregability was increased more in patients with moderate-to-severe OSA (3%ODI 15) than in patients with non-to-mild OSA (p 0.029). In multiple linear models, 3%ODI significantly contributed to increased platelet aggregability induced by both ADP and collagen among 59 subjects with one or more risk factors for vascular diseases, such as smoking, hypertension, diabetes mellitus or hyperlipidemia. In 23 patients treated by nCPAP, collagen-induced platelet aggregability was ameliorated on Day 90, compared to at the baseline. Conclusion: The severity of OSA significantly contributed to platelet aggregability, which was improved by nCPAP treatment partially at three months.

No abstract

SUMMARY The regulatory role of chemokines and chemokine receptors on specific lymphocyte recruitment into periodontal diseased tissue is poorly characterized. We observed that lymphocytes infiltrating inflamed gingival tissue expressed marked levels of CCR6. In periodontal diseased tissue, the expression of MIP‐3α mRNA was detected by RT‐PCR and further, MIP‐3α was distributed in the basal layer of gingival epithelial cells, microvascular endothelial cells and the areas of inflammatory cells as shown by immunohistochemistry. Moreover, CCR6‐expressing cells infiltrated into periodontal diseased tissue, and the proportion of CCR6‐positive CD4+ T cells was significantly elevated in periodontal diseased tissue compared with peripheral blood in the same patients. Furthermore, gingival lymphocytes isolated from patients showed migration toward MIP‐3α in an in vitro chemotaxis assay in which migration was abrogated by specific antibody to CCR6. Thus, these findings suggested that CCR6 and the corresponding chemokine, MIP‐3α may have an important regulatory role in specific lymphocyte migration into inflamed periodontal tissue.

Summary Streptococcus intermedius