Inflammatory and immune pathways in the pathogenesis of periodontal disease.
Cekici Ali,Kantarci Alpdogan,Hasturk Hatice,Van Dyke Thomas E
The pathogenesis of periodontitis involves a complex immune/inflammatory cascade that is initiated by the bacteria of the oral biofilm that forms naturally on the teeth. The susceptibility to periodontitis appears to be determined by the host response; specifically, the magnitude of the inflammatory response and the differential activation of immune pathways. The purpose of this review was to delineate our current knowledge of the host response in periodontitis. The role of innate immunity, the failure of acute inflammation to resolve (thus becoming chronic), the cytokine pathways that regulate the activation of acquired immunity and the cells and products of the immune system are considered. New information relating to regulation of both inflammation and the immune response will be reviewed in the context of susceptibility to, and perhaps control of, periodontitis.
Carbon monoxide-releasing molecule-3 suppresses Prevotella intermedia lipopolysaccharide-induced production of nitric oxide and interleukin-1β in murine macrophages.
Choi Eun-Young,Choe So-Hui,Hyeon Jin-Yi,Choi Jeom-Il,Choi In Soon,Kim Sung-Jo
European journal of pharmacology
This study was performed to analyze the effect of carbon monoxide (CO)-releasing molecule-3 (CORM-3) in alleviating the production of proinflammatory mediators in macrophages treated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen associated with periodontal disease, and its possible mechanisms of action. LPS was isolated using the hot phenol-water method. Culture supernatants were assayed for nitric oxide (NO) and interleukin-1β (IL-1β). Gene expression was quantified by real-time PCR, and protein expression by immunoblotting. DNA-binding activities of NF-κB subunits were determined using an ELISA-based kit. CORM-3 suppressed the production of inducible NO synthase (iNOS)-derived NO and IL-1β at both gene transcription and translation levels in P. intermedia LPS-activated RAW264.7 cells. CORM-3 enhanced heme oxygenase-1 (HO-1) expression in cells stimulated with P. intermedia LPS, and inhibition of HO-1 activity by SnPP notably reversed the suppressive effect of CORM-3 on LPS-induced production of NO. LPS-induced phosphorylation of p38 and JNK was not affected by CORM-3. CORM-3 did not influence P. intermedia LPS-induced degradation of IκB-α. Instead, nuclear translocation of NF-κB p65 and p50 subunits was blocked by CORM-3 in LPS-treated cells. In addition, CORM-3 reduced LPS-induced p65 and p50 binding to DNA. Besides, CORM-3 significantly suppressed P. intermedia LPS-induced phosphorylation of STAT1. Overall, this study indicates that CORM-3 suppresses the production of NO and IL-1β in P. intermedia LPS-activated murine macrophages via HO-1 induction and inhibition of NF-κB and STAT1 pathways. The modulation of host inflammatory response by CORM-3 would be an attractive therapeutic approach to attenuate the progression of periodontal disease.
Periodontal pathogens directly promote autoimmune experimental arthritis by inducing a TLR2- and IL-1-driven Th17 response.
de Aquino Sabrina G,Abdollahi-Roodsaz Shahla,Koenders Marije I,van de Loo Fons A J,Pruijn Ger J M,Marijnissen Renoud J,Walgreen Birgitte,Helsen Monique M,van den Bersselaar Liduine A,de Molon Rafael S,Avila Campos Mario J,Cunha Fernando Q,Cirelli Joni A,van den Berg Wim B
Journal of immunology (Baltimore, Md. : 1950)
Increasing epidemiologic evidence supports a link between periodontitis and rheumatoid arthritis. The actual involvement of periodontitis in the pathogenesis of rheumatoid arthritis and the underlying mechanisms remain, however, poorly understood. We investigated the influence of concomitant periodontitis on clinical and histopathologic characteristics of T cell-mediated experimental arthritis and evaluated modulation of type II collagen (CII)-reactive Th cell phenotype as a potential mechanism. Repeated oral inoculations of periodontal pathogens Porphyromonas gingivalis and Prevotella nigrescens induced periodontitis in mice, as evidenced by alveolar bone resorption. Interestingly, concurrent periodontitis induced by both bacteria significantly aggravated the severity of collagen-induced arthritis. Exacerbation of arthritis was characterized by increased arthritic bone erosion, whereas cartilage damage remained unaffected. Both P. gingivalis and P. nigrescens skewed the CII-specific T cell response in lymph nodes draining arthritic joints toward the Th17 phenotype without affecting Th1. Importantly, the levels of IL-17 induced by periodontal pathogens in CII-specific T cells directly correlated with the intensity of arthritic bone erosion, suggesting relevance in pathology. Furthermore, IL-17 production was significantly correlated with periodontal disease-induced IL-6 in lymph node cell cultures. The effects of the two bacteria diverged in that P. nigrescens, in contrast to P. gingivalis, suppressed the joint-protective type 2 cytokines, including IL-4. Further in vitro studies showed that the Th17 induction strongly depended on TLR2 expression on APCs and was highly promoted by IL-1. Our data provide evidence of the involvement of periodontitis in the pathogenesis of T cell-driven arthritis through induction of Ag-specific Th17 response.
The immune response to Prevotella bacteria in chronic inflammatory disease.
Larsen Jeppe Madura
The microbiota plays a central role in human health and disease by shaping immune development, immune responses and metabolism, and by protecting from invading pathogens. Technical advances that allow comprehensive characterization of microbial communities by genetic sequencing have sparked the hunt for disease-modulating bacteria. Emerging studies in humans have linked the increased abundance of Prevotella species at mucosal sites to localized and systemic disease, including periodontitis, bacterial vaginosis, rheumatoid arthritis, metabolic disorders and low-grade systemic inflammation. Intriguingly, Prevotella abundance is reduced within the lung microbiota of patients with asthma and chronic obstructive pulmonary disease. Increased Prevotella abundance is associated with augmented T helper type 17 (Th17) -mediated mucosal inflammation, which is in line with the marked capacity of Prevotella in driving Th17 immune responses in vitro. Studies indicate that Prevotella predominantly activate Toll-like receptor 2, leading to production of Th17-polarizing cytokines by antigen-presenting cells, including interleukin-23 (IL-23) and IL-1. Furthermore, Prevotella stimulate epithelial cells to produce IL-8, IL-6 and CCL20, which can promote mucosal Th17 immune responses and neutrophil recruitment. Prevotella-mediated mucosal inflammation leads to systemic dissemination of inflammatory mediators, bacteria and bacterial products, which in turn may affect systemic disease outcomes. Studies in mice support a causal role of Prevotella as colonization experiments promote clinical and inflammatory features of human disease. When compared with strict commensal bacteria, Prevotella exhibit increased inflammatory properties, as demonstrated by augmented release of inflammatory mediators from immune cells and various stromal cells. These findings indicate that some Prevotella strains may be clinically important pathobionts that can participate in human disease by promoting chronic inflammation.
Gut microbiota in 2015: Prevotella in the gut: choose carefully.
Ley Ruth E
Nature reviews. Gastroenterology & hepatology
Gut microbial communities often contain many Bacteroides or their close relatives, Prevotella, but not both. Prevotella strains are associated with plant-rich diets but are also linked with chronic inflammatory conditions. In 2015, papers probed the genomic diversity of Prevotella strains and interactions of Prevotella copri with its host and other bacteria.
NCX 4040, a nitric oxide-donating aspirin derivative, inhibits Prevotella intermedia lipopolysaccharide-induced production of proinflammatory mediators in murine macrophages.
Choi Eun-Young,Choe So-Hui,Hyeon Jin-Yi,Park Hae Ryoun,Choi Jeom-Il,Choi In Soon,Kim Sung-Jo
European journal of pharmacology
In this study, the effects and underlying mechanisms of NCX 4040, a nitric oxide (NO)-donating aspirin derivative, on the production of proinflammatory mediators were examined using murine macrophages exposed to lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen implicated in the etiology of periodontal disease. NCX 4040 significantly reduced P. intermedia LPS-induced production of inducible NO synthase (iNOS)-derived NO, IL-1β and IL-6 as well as their mRNA expression in RAW264.7 cells. Notably, NCX 4040 was much more effective than the parental compound aspirin in reducing LPS-induced production of inflammatory mediators. NCX 4040 induced the expression of heme oxygenase-1 (HO-1) in cells treated with P. intermedia LPS, and the suppressive effect of NCX 4040 on LPS-induced NO production was significantly reversed by SnPP, a competitive HO-1 inhibitor. NCX 4040 did not influence LPS-induced phosphorylation of JNK and p38. IκB-α degradation as well as nuclear translocation and DNA-binding activities of NF-κB p65 and p50 subunits induced by P. intermedia LPS were significantly reduced by NCX 4040. Besides, LPS-induced phosphorylation of STAT1 and STAT3 was significantly down-regulated by NCX 4040. Further, NCX 4040 elevated the SOCS1 mRNA in cells stimulated with LPS. This study indicates that NCX 4040 inhibits P. intermedia LPS-induced production of NO, IL-1β and IL-6 in murine macrophages through anti-inflammatory HO-1 induction and suppression of NF-κB, STAT1 and STAT3 activation, which is associated with the activation of SOCS1 signaling. NCX 4040 could potentially be a promising tool in the treatment of periodontal disease, although further studies are required to verify this.
Telmisartan, an angiotensin II receptor blocker, attenuates Prevotella intermedia lipopolysaccharide-induced production of nitric oxide and interleukin-1β in murine macrophages.
Choe So-Hui,Choi Eun-Young,Hyeon Jin-Yi,Keum Bo Ram,Choi In Soon,Kim Sung-Jo
Telmisartan, widely prescribed for the treatment of hypertension, has an anti-inflammatory property in addition to being an angiotensin II type 1 receptor antagonist. This study was carried out to explore the influence of telmisartan upon the elaboration of inflammatory mediators in murine macrophages stimulated with lipopolysaccharide (LPS) prepared from Prevotella intermedia, a periodontal pathogen, as well as its molecular mechanisms. Telmisartan significantly inhibited LPS-induced generation of inducible nitric oxide (NO) synthase-derived NO and interleukin-1β (IL-1β) as well as their gene expressions in RAW264.7 cells. Telmisartan treatment of LPS-activated cells significantly up-regulated arginase 1 (Arg-1) and chitinase-like 3 (Ym-1), which are specific markers of M2 macrophages. Telmisartan caused a significant increase in heme oxygenase-1 (HO-1) expression in cells stimulated with LPS, and its inhibitory action against NO production was reversed by treatment with SnPP, an HO-1 inhibitor. Phosphorylation of STAT1 and STAT3 induced by LPS was attenuated by telmisartan. Telmisartan inhibited LPS-induced generation of NO and IL-1β independently of PPAR-γ activation. In addition, activation of NF-κB as well as JNK and p38 signaling induced by LPS was not modulated by telmisartan. In summary, telmisartan is a potent inhibitor of P. intermedia LPS-induced generation of NO and IL-1β in RAW264.7 cells and promotes macrophage phenotype switching toward the M2 phenotype. Telmisartan may have potential to be developed into host modulatory agent for inflammatory periodontal disease, although additional studies are needed to confirm the therapeutic effect.
Josamycin suppresses Prevotella intermedia lipopolysaccharide-induced production of nitric oxide and interleukin-1β in murine macrophages.
Choi Eun-Young,Choe So-Hui,Hyeon Jin-Yi,Park Hae Ryoun,Choi In Soon,Kim Sung-Jo
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
AIMS:Josamycin has immunomodulatory properties independent of its antibacterial actions. This study was designed to explore the influences and associated mechanisms of josamycin upon the generation of proinflammatory mediators in murine macrophages activated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogenic bacterium associated with periodontal disease. MAIN METHODS:LPS was purified by employing phenol-water extraction protocol. Culture supernatants were analyzed for nitric oxide (NO) and interleukin (IL)-1β. Real-time PCR and immunoblotting were conducted to quantify mRNA and protein expression, respectively. The expression levels of IL-1β were analyzed by confocal laser scanning microscopy. NF-κB-dependent SEAP levels were estimated by reporter assay. KEY FINDINGS:Josamycin significantly attenuated NO production elicited by P. intermedia LPS as well as induction of iNOS protein and mRNA in RAW264.7 cells. While the release of IL-1β from cells stimulated by LPS was suppressed in the presence of josamycin, josamycin failed to reduce the degree of IL-1β mRNA expression. Josamycin did not reduce the stability of IL-1β mRNA induced by P. intermedia LPS, at the same time josamycin also failed to suppress the LPS-induced intracellular IL-1β expression. Josamycin augmented HO-1 induction in cells exposed to P. intermedia LPS, and SnPP, an inhibitor of HO-1 activity, reversed the suppressive impact of josamycin upon NO generation induced by LPS. Josamycin diminished NF-κB transcriptional activity induced by P. intermedia LPS. Further, josamycin enhanced SOCS1 mRNA level in cells activated with LPS. SIGNIFICANCE:Josamycin suppressed P. intermedia LPS-induced generation of NO and IL-1β in RAW264.7 macrophages via the inhibition of NF-κB activation as well as HO-1 and SOCS1 induction. Josamycin may have benefits as a host modulatory agent in treating periodontal disease.