LECT2 mediates antibacterial immune response induced by Nocardia seriolae infection in the northern snakehead.

Leukocyte-derived chemotaxin-2 (LECT2) is a multifunctional immunoregulator that plays several pivotal roles in the host's defense against pathogens. This study aimed to elucidate the specific functions and mechanisms of LECT2 (CaLECT2) in the northern snakehead (Channa argus) during infections with pathogens such as Nocardia seriolae (N. seriolae). We identified CaLECT2 in the northern snakehead, demonstrating its participation in the immune response to N. seriolae infection. CaLECT2 contains an open reading frame (ORF) of 459 bp, encoding a peptide of 152 amino acids featuring a conserved peptidase M23 domain. The CaLECT2 protein shares 62%-84 % identities with proteins from various other fish species. Transcriptional expression analysis revealed that CaLECT2 was constitutively expressed in all examined tissues, with the highest expression observed in the liver. Following intraperitoneal infection with N. seriolae, CaLECT2 transcription increased in the spleen, trunk kidney, and liver. In vivo challenge experiments showed that injecting recombinant CaLECT2 (rCaLECT2) could protect the snakehead against N. seriolae infection by reducing bacterial load, enhancing serum antibacterial activity and antioxidant capacity, and minimizing tissue damage. Moreover, in vitro analysis indicated that rCaLECT2 significantly enhanced the migration, respiratory burst, and microbicidal activity of the head kidney-derived phagocytes. These findings provide new insights into the role of LECT2 in the antibacterial immunity of fish.

[Effect of peroxisome proliferator-activated receptor-γ on endothelial cells oxidative stress induced by Porphyromonas gingivalis].

OBJECTIVE: To detect the degree of oxidative stress in the process when Porphyromonas gingivalis (P. gingivalis) stimulates human vascular endothelium, And to investigate the effect of peroxisome proliferator-activated receptor(PPAR)γ on oxidative stress during this process. METHODS: Human vascular endothelial cells (HVECs) line EA.hy926 (American Type Culture Collection ,United States) was cultured in high glucose Dulbecco's modified eagle medium (DMEM). Four groups were designed: control group, P. gingivalis infected group, PPARγ activated group and PPARγ blocked group. In control group HVECs were cultured with only DMEM. In P. gingivalis infected group, HVECs were time-dependently stimulated by P. gingivalis W83 from 0 to 12 h. In PPARγ activated group or PPARγ blocked group, PPARγ was pre-activated or blocked by a representative PPARγ agonist(15d-PGJ2 10 µmol/L) or antagonist (GW966210 µmol/L) 30 minutes before the cells were stimulated by P. gingivalis. At 0, 0.5, 1, 1.5, 2, 4, 8, and 12 h, the culture medium was collected individually and centrifuged, and the supernatant was stored for assay. Glutathione peroxidase (GSH-PX) and malondialdehyde (MDA) were analysed by enzyme-linked immunosorbent assay. Cellular reactive oxygen species (ROS) were detected through 2',7'-dichlorofluorescin diacetate (DCFA-DA) fluorescent probe at various time points of the different groups. RESULTS: In P. gingivalis infected group, the levels of GSH-PX [(5.56±0.97) µmol/L] and MDA [(0.84±0.18) nmol/L] were significantly higher than those in control group [GSH-PX(4.71±0.64) µmol/L, MDA (0.59±0.18) nmol/L)]. The levels of GSH-PX and MDA in PPARγ activated group [GSH-PX (5.38±0.84) µmol/L, MDA (0.84±0.22) nmol/L] and in PPARγ blocked group [GSH-PX (5.37±0.76) µmol/L, MDA (0.85±0.14) nmol/L] were significantly higher than those in control group (P<0.05). In the PPARγ activated group, the levels of GSH-PX at 0.5 and 8 h were significantly higher than those from 1.5 h to 4 h (P<0.05), while no difference was observed on the MDA levels at different time points. There was no significant difference at various time points for the levels of GSH-PX and MDA in PPARγ blocked group. The level of cellular ROS detected by DCFH-DA in P. gingivalis infected group was significantly higher than that in control group (10 108.65 ± 1 805.18 vs. 6 049.06 ± 1 199.19,P<0.05). No difference was observed between PPARγ activated group (7 120.94±1 447.30) or PPARγ blocked group (6 727.35±1 483.68) and control group. CONCLUSION: Oxidative stress happens when P. gingivalis stimulates human vascular endothelium. PPARγ may involve in modulating oxidative stress during this process.

Modified approach of regenerative treatment for distal intrabony defect beneath non-keratinized mucosa at terminal molar: A case report.

BACKGROUND: Intrabony defects beneath non-keratinized mucosa are frequently observed at the distal site of terminal molars. Consequently, the application of regenerative treatment using the modified wedge-flap technique is considered impractical for these specific dental conditions. CASE SUMMARY: This article proposes a modified surgical procedure aimed at exposing the distal intrabony defect by making a vertical incision in the keratinized buccal gingiva. The primary objective is to maintain gingival flap stability, thereby facilitating periodontal regeneration. The described technique was successfully employed in a case involving the left mandibular second molar, which presented with an intrabony defect without keratinized gingiva at the distal site. In this case, an incision was made on the disto-buccal gingival tissue, creating a tunnel-like separation of the distal non-keratinized soft tissue to expose the intrabony defect. Subsequently, bone grafting and guided tissue regeneration surgeries were performed, resulting in satisfactory bone fill at 9 mo postoperatively. CONCLUSION: This technique offers a regenerative opportunity for the intrabony defects beneath non-keratinized mucosa and is recommended for further research.

The expression levels of chemotaxis-related molecules CXC chemokine receptor 1, interleukin-8, and pro-platelet basic protein in gingival tissues.

Background/purpose: Excessive host immune response is thought to be an important cause of periodontal tissue damage during periodontitis. The potent chemotaxis produced by locally released chemokines is the key signal to trigger this response. Here, we aimed to investigate the expression of CXC chemokine receptor 1 (CXCR1), and chemokines interleukin-8 (IL-8) and pro-platelet basic protein (PPBP) in human inflammatory gingival tissues compared with healthy tissues. Materials and methods: A total of 54 human gingival tissues, 27 healthy and 27 inflammatory samples, were collected. Fifteen specimens of each group were employed for quantitative reverse transcription polymerase chain reaction to determine the mRNA levels of CXCR1, IL-8, and PPBP. Six samples of each group were used for Western blotting to investigate the protein expression of CXCR1 and for enzyme-linked immunosorbent assay to evaluate the protein levels of IL-8 and PPBP, respectively. Results: The mRNA levels of chemokine receptor CXCR1, chemokine IL-8, and PPBP in inflammatory gingival tissues were significantly higher than those in healthy controls (P < 0.05). The protein levels of CXCR1, IL-8, and PPBP in inflammatory gingival tissues were also significantly higher than those in healthy gingival tissues (P < 0.05). Conclusion: When compared to healthy gingival tissues, the expression of CXCR1, IL-8, and PPBP in inflammatory gingival tissues is higher.

Subgingival Microbial Profiles of Young Chinese Adults with Stage I/II Periodontitis, Gingivitis and Periodontal Health Status.

OBJECTIVE: To analyse the subgingival microbiota of Stage I/II periodontitis, gingivitis with different degrees of severity, and periodontal health in subjects in a Chinese young adult population. METHODS: Subgingival plaque samples were collected from 15 Stage I/II periodontitis patients, 38 gingivitis patients and 15 periodontally healthy individuals, all aged from 18 to 21 years. Gingivitis patients were divided into two subgroups according to the Bleeding Index (BI) of their sampled teeth: gingivitis with above median BI (G-HBI) and below median BI (G-LBI). The subgingival plaque samples were collected from teeth 16, 26, 36, 46, 11 and 31 according to FDI notation. The V3-V4 region of the 16S rRNA gene of all the samples was sequenced and analysed. RESULTS: The Stage I/II periodontitis, gingivitis and periodontal health groups showed distinct subgingival microbiota profiles. When the gingivitis patients were stratified into two subgroups, the community structure of G-HBI showed no significant difference from early-stage periodontitis, but differed from G-LBI and the healthy group. Most periodontitis-related taxa were most abundant in Stage I/II periodontitis, followed by G-HBI, G-LBI and the periodontally healthy group. Porphyromonas gingivalis, Filifactor alocis, Tannerella forsythia, Saccharibacteria TM7 G-5 356, Lachnospiraceae G-8 500, Peptostreptococcaceae spp. and Syntrophomonadaceae VIIIG-1 435 were associated with Stage I/II periodontitis. Porphyromonas 275, Leptotrichia 417 and Saccharibacteria TM7 G-2 350 were associated with gingivitis. Porphyromonas gingivalis was significantly more abundant in G-HBI than in G-LBI. CONCLUSION: Within the limitations of this preliminary study, gingivitis and early-stage periodontitis were associated with an increased degree of dysbiosis in the subgingival microbiota in a Chinese young adult population.