Streptococcus pneumoniae is an important causative organism of respiratory tract infections. Although periodontal bacteria have been shown to influence respiratory infections such as aspiration pneumonia, the synergistic effect of S. pneumoniae and Porphyromonas gingivalis, a periodontopathic bacterium, on pneumococcal infections is unclear. To investigate whether P. gingivalis accelerates pneumococcal infections, we tested the effects of inoculating P. gingivalis culture supernatant (PgSup) into S. pneumoniae-infected mice. Mice were intratracheally injected with S. pneumoniae and PgSup to induce pneumonia, and lung histopathological sections and the absolute number and frequency of neutrophils and macrophages in the lung were analyzed. Proinflammatory cytokine/chemokine expression was examined by qPCR and ELISA. Inflammatory cell infiltration was observed in S. pneumoniae-infected mice and S. pnemoniae and PgSup mixed-infected mice, and mixed-infected mice showed more pronounced inflammation in lung. The ratios of monocytes/macrophages and neutrophils were not significantly different between the lungs of S. pneumoniae-infected mice and those of mixed-infected mice. PgSup synergistically increased TNF-α expression/production and IL-17 production compared with S. pneumoniae infection alone. We demonstrated that PgSup enhanced inflammation in pneumonia caused by S. pneumoniae, suggesting that virulence factors produced by P. gingivalis are involved in the exacerbation of respiratory tract infections such as aspiration pneumonia.

The effect of Mfa1 fimbriae of Porphyromonas gingivalis on the progression of bone resorption remains unclear, especially compared with another fimbriae, FimA. We investigated the effect of Mfa1 on osteoclastogenesis together with FimA. We also investigated the role of Toll-like receptors (TLRs) in Mfa1 recognition during osteoclast differentiation. Receptor activator of nuclear factor κβ ligand (RANKL)-prestimulated RAW264 cells were used to examine the effects of purified Mfa1 fimbriae. The number of osteoclasts was examined by tartrate-resistant acid phosphate (TRAP) staining, osteoclast activation was investigated by bone resorption assays, and gene expression of differentiation markers was examined by quantitative real-time PCR. Transfection of Tlr2 and Tlr4 siRNAs into RAW264 cells was also employed and their role in Mfa1 recognition was investigated. Mfa1 effectively induced the formation of TRAP-positive multinucleated cells and activated osteoclasts. Mfa1 also increased gene expression of Acp5, Mmp9, and Ctsk in RANKL-prestimulated RAW264 cells compared with the control. The osteoclastogenesis induced by Mfa1 was significantly decreased in cells transfected with Tlr2 or Tlr4 siRNAs compared with control siRNA. Our results revealed the role of Mfa1 fimbriae in osteoclastogenesis that may contribute to the partial elucidation of the mechanisms of periodontal disease progression and the development of new therapeutic strategies.

Porphyromonas gingivalis Mfa1 fimbriae are thought to act as adhesion factors and to direct periodontal tissue destruction but their immunomodulatory actions are poorly understood. Here, we investigated the effect of Mfa1 stimulation on the immune and metabolic mechanisms of gingival fibroblasts from periodontal connective tissue. We also determined the role of Toll-like receptor (TLR) 2 and TLR4 in Mfa1 recognition. Mfa1 increased the expression of genes encoding chemokine (C-X-C motif) ligand (CXCL) 1, CXCL3, intercellular adhesion molecule (ICAM) 1 and Selectin endothelium (E) in gingival fibroblasts, but did not have a significant effect on genes that regulate metabolism. Mfa1-stimulated up-regulation of genes was significantly suppressed in Tlr4 siRNA-transfected cells compared with that in control siRNA-transfected cells, which indicates that recognition by TLR4 is essential for immunomodulation by Mfa1. Additionally, suppression of Tlr2 expression partially attenuated the stimulatory effect of Mfa1. Overall, these results help explain the involvement of P. gingivalis Mfa1 fimbriae in the progression of periodontal disease.

Endometriosis is a chronic gynecological disorder characterized by the ectopic growth and proliferation of endometrial tissue outside the uterine cavity, leading to inflammation. Although low‑dose contraceptive pills are widely used for its treatment, these therapies are associated with side effects and are contraindicated in women trying to conceive. ε‑viniferin is a resveratrol dimer found in wild grapes (Ampelopsis brevipedunculata) with demonstrated antioxidant properties and an anti‑migratory effect in lung cancer cells. Because abnormal cell migration is a key process in endometriosis, we hypothesized that ε‑viniferin could also exhibit anti‑migratory effects in endometriotic cells, which remain to be elucidated. To test this hypothesis, the present study investigated the anti‑inflammatory and anti‑endometriotic effects of ε‑viniferin and wild‑grape extract. RAW264.7 and THP‑1 were used to evaluate the anti‑inflammatory effects of wild‑grape extract and ε‑viniferin by assessing cytotoxicity; nitric oxide (NO), reactive oxygen species and interleukin‑6 (IL‑6) production; and NF‑κB activity. Additionally, human endometrial stromal cells (HESCs) were used to investigate the anti‑endometriotic effects of ε‑viniferin, including its impact on cell migration, invasion and gene expression, using PCR array analysis. Both ε‑viniferin and wild‑grape extract significantly reduced lipopolysaccharide‑induced NO and IL‑6 production, indicating an anti‑inflammatory activity. Inhibition of NF‑κB activity at the cellular level further supported these findings. Moreover, both ε‑viniferin and wild‑grape extract effectively suppressed the migration and invasion of HESCs, indicating their potential to alleviate endometriosis symptoms. These findings suggest that ε‑viniferin is a promising therapeutic candidate for endometriosis, exhibiting both anti‑inflammatory and anti‑migratory effects. Our results present a novel approach for developing effective anti‑endometriotic therapies.

Objective: Simulated microgravity (SMG) alters fluid dynamics and may influence microbial aggregation. However, its effects on oral bacteria remain unclear. This study investigated the effects of SMG on the growth and aggregation of representative oral bacteria. Methods: Four facultative oral bacteria representing distinct ecological and adhesive properties—Staphylococcus aureus(opportunistic pathogen), Streptococcus mutans (glucan-producing cariogenic bacterium), Streptococcus salivarius (commensal fructan-producing bacterium), and Streptococcus sanguinis (early colonizer)—together with the periodontal pathogen Porphyromonas gingivalis were cultured under SMG (10⁻³G) or normal gravity (NG). Streptococci were grown with or without sucrose to evaluate the role of extracellular polysaccharides. Growth was assessed by optical density, and aggregation was quantified by image analysis. Results: SMG induced aggregation in a species-dependent manner. S. mutans and S. salivarius formed spherical aggregates under SMG, whereas little or no aggregate formation was observed in S. aureus, S. sanguinis, or P. gingivalis. Aggregation of S. mutans was markedly reduced without sucrose, indicating dependence on glucan-mediated adhesion. S. salivarius also showed reduced aggregation under sucrose-free conditions, although limited aggregation persisted. Growth kinetics were virtually unaffected by SMG. Conclusions: SMG promotes aggregation of selected oral bacteria through species-specific mechanisms. These findings suggest that microgravity may alter the architecture of oral microbial communities by enhancing particular intercellular adhesion pathways.