Molecular pathogenicity of 1-nonadecene and L-lactic acid, unique metabolites in radicular cysts and periapical granulomas.

Recently, 1-nonadecene and L-lactic acid were identified as unique metabolites in radicular cysts and periapical granuloma, respectively. However, the biological roles of these metabolites were unknown. Therefore, we aimed to investigate the inflammatory and mesenchymal-epithelial transition (MET) effects of 1-nonadecene, and the inflammatory and collagen precipitation effects of L-lactic acid on both periodontal ligament fibroblasts (PdLFs) and peripheral blood mononuclear cells (PBMCs). PdLFs and PBMCs were treated with 1-nonadecene and L-lactic acid. Cytokines' expression was measured using quantitative real-time polymerase chain reaction (qRT-PCR). E-cadherin, N-cadherin, and macrophage polarization markers were measured using flow cytometry. The collagen, matrix metalloproteinase (MMP)-1, and released cytokines were measured using collagen assay, western blot, and Luminex assay, respectively. In PdLFs, 1-nonadecene enhances inflammation through the upregulation of some inflammatory cytokines including IL-1ß, IL-6, IL-12A, monocyte chemoattractant protein (MCP)-1, and platelet-derived growth factor (PDGF) α. 1-Nonadecene also induced MET through the upregulation of E-cadherin and the downregulation of N-cadherin in PdLFs. 1-Nonadecene polarized macrophages to a pro-inflammatory phenotype and suppressed their cytokines' release. L-lactic acid exerted a differential impact on the inflammation and proliferation markers. Intriguingly, L-lactic acid induced fibrosis-like effects by enhancing collagen synthesis, while inhibiting MMP-1 release in PdLFs. These results provide a deeper understanding of 1-nonadecene and L-lactic acid's roles in modulating the microenvironment of the periapical area. Consequently, further clinical investigation can be employed for target therapy.

The Essential Role of 17-Octadecynoic Acid in the Pathogenesis of Periapical Abscesses.

INTRODUCTION: Periapical abscesses are 1 of the most frequent pathologic lesions in the alveolar bone. Recently, we have identified 17-octadecynoic acid (17-ODYA) as the highest unique metabolite in periapical abscesses. Therefore, the aim of this study was to investigate the immunologic and pathophysiological roles of this metabolite in the initiation and development of periapical abscesses. METHODS: Periodontal ligament fibroblasts and peripheral blood mononuclear cells were treated with 17-ODYA. Gene expression analysis and interleukin (IL)-8 release were determined using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Macrophage polarization and cytokine release were also determined using flow cytometry and Luminex bioassay (R&D Systems, Minneapolis, MN), respectively. RESULTS: In periodontal ligament fibroblasts, 17-ODYA caused significant (P < .0001) up-regulation of IL-1α, IL-1ß, IL-6, matrix metalloproteinase-1, and monocyte chemoattractant protein-1 at 10 µmol/L after 6 days of treatment and up-regulation of platelet-derived growth factor alpha and vascular endothelial growth factor alpha at all tested concentrations after 2 days of treatment. In peripheral blood mononuclear cells, 17-ODYA significantly increased the expression of IL-1α, IL-1ß, IL-6, matrix metalloproteinase-1, and monocyte chemoattractant protein-1 at 10 µmol/L (P < .0001) and vascular endothelial growth factor alpha and platelet-derived growth factor alpha at 1 µmol/L 17-ODYA (P < .0001). 17-ODYA polarized macrophages toward a proinflammatory phenotype (M1) and suppressed the release of pro- and anti-inflammatory cytokines. 17-ODYA significantly enhanced the release of IL-8. CONCLUSIONS: This study was the first to identify the pathologic role of 17-ODYA in the development of periapical abscesses. The results of this study are important in shedding light on the pathogenesis of periapical abscesses in relation to microbial metabolites.

Haptoglobin polymorphism modulates cardiometabolic impacts of four consecutive weeks, dawn to sunset Ramadan intermittent fasting among subjects with overweight/obesity.

AIMS: Haptoglobin (Hp) is a multifaceted marker of inflammation, and mediates the interplay between obesity, inflammation, and cardiometabolic dysfunction. However, the role of the Hp phenotype in modulating intermittent fasting (IF)-induced cardiometabolic changes remains to be elucidated. METHODS: Hp phenotype was determined for the study subjects. Cardiometabolic markers were assessed before and at the end of four consecutive weeks, dawn to sunset IF. RESULTS: A total of 114 subjects (75 males and 39 females, 38.7 ± 11.7 years, body mass index (BMI) of 30.41 ± 5.09 kg/m2) were recruited. Hp2-2 (n = 55, 48.2 %) and Hp2-1 (n = 53, 46.5 %) were the predominant phenotypes. Significant reductions were observed in serum Hp, IL-6, TNF-α, triglycerides (TG), total cholesterol (TC), LDL, BMI, and fat mass (FM), while a significant elevation was observed in serum CD163, HDL, and IL-10 at the end of the IF month for the whole population. Based on the Hp polymorphism, significant decreases in Hp, BMI, FM, TG, LDL, and TNF-α, with significant increases in HDL and CD163 levels were observed among subjects with Hp2-2 and Hp2-1 phenotypes. A more pronounced reduction in FM was reported in subjects with Hp2-2 in comparison with Hp2-1. CONCLUSION: Hp gene polymorphism modulates IF-induced changes in cardiometabolic markers. CLINICAL TRIAL REGISTRATION NUMBER: ISRCTN18205186; https://trialsearch.who.int/?TrialID=ISRCTN18205186.