[Periodontitis Promotes the Progression of Oral Squamous Cell Carcinoma by Inducing Macrophage M2 Polarization].

Objective: To investigate the role of periodontitis in the development of oral squamous cell carcinoma (OSCC) and to determine whether periodontitis microorganisms induce M2 macrophage (M2) polarization and promote tumor progression. Methods: The tumor tissues of OSCC patients with periodontitis and those without periodontitis were collected and immunohistochemistry tests were done to validate the trend of changes in M2 macrophages. A mouse model of OSCC accompanied by periodontitis was established by treating mice with drinking water containing four antibiotics for three consecutive days, applying in the mouths of the mice a coat of bacteria collected from the saliva of patients with periodontitis once every other day for five times, and injecting in their buccal mucosa OSCC cells (SCC7). We observed the effect of periodontitis on the development of OSCC, analyzed the M2 macrophage content in the tumor tissues, and analyzed salivary microbiota structure, and examined the pathological changes in the spleen and colon tissues of the mice. Finally, we collected saliva from patients with periodontitis, co-cultured it with mice peripheral blood mononuclear cells (PBMC) and SCC7 cells, and examined M2 macrophage percentage by flow cytometry. Results: Immunohistochemical findings from the clinical samples showed that M2-polarized macrophages in OSCC patients with periodontitis were more enriched (27.01%±2.12%) compared with those of OSCC patients without periodontitis (17.00%±3.66%). The OSCC mice with periodontitis (PO group) had tumors of larger size and lower survival rate than OSCC mice (O group) did. Furthermore, the expression rate of Ki67-positive cells (35.49%±5.00%) was significantly higher than that of O group (23.89%±4.13%) ( P<0.05). According to the results of flow cytometry, M2 macrophage expression (24.97%±4.41%) in PO group was higher than that of O group (5.75%±0.52%) ( P<0.05). In addition, qPCR results showed that gene expression of M2 macrophage-related factors, Arg1, IL-10, and CD206, showed an overall upward trend. Immunohistochemistry results showed that the positive expression of M2 macrophages was significantly increased in the PO group (21.82%±4.16%) compared to that of the O group (9.64%±0.60%) ( P<0.05). Mice in the PO group showed changes in their oral flora structure, exhibiting increased bands and diversity. The white pulp in their spleen tissue decreased and the boundary of the red pulp became indistinct with severe bleeding. The morphology of the colon glands was abnormal and the U-shaped crypt was damaged rather seriously. According to the results of cell experiment, when co-culturing PBMC with SCC7 cells, the presence of periodontitis microorganisms increased the polarization of M2 macrophages (71.00%±0.66%). Conclusion: Periodontitis promotes the development of OSCC by inducing M2 polarization in tumor-associated macrophages. Hence, periodontitis treatment holds important values for OSCC patients.

[Synergistic Antibacterial Activity of Berberine in Combination with Amylmetacresol Against Enterococcus faecalis in vitro].

OBJECTIVE: To study the antibacterial effect of berberine combined with amylmetacresol on Enterococcus faecalis. METHODS: Both dilution method and live bacteria CFU were used to determine the minimum inhibitory concentration (MIC) of berberine and amylmetacresol on E. faecalis. The killing effect of berberine and amylmetacresol on planktonic E. faecalis was detected by suspension quantitative germicidal test and live/dead bacteria staining. The effects of berberine and amylmetacresol on the structure of mature biofilm of E. faecalis was observed by scanning electron microscopy (SEM). The toxicity of berberine and amylmetacresol on human oral keratinocytes (HOK) was determined by CCK-8 cell proliferation and cytotoxicity assay and cytotoxicity LDH assay. RESULTS: The MIC of berberine was 512 µg/mL, and the MIC of amylmetacresol was 0.023 3%. 512 µg/mL berberine and 0.002 33% amylmetacresol had a weak killing effect on planktonic E. faecalis alone, while they showed a synergistic antibacterial effect in combination. Cell survival in the biofilm was only slightly changed by berberine and amylmetacresol. The structure of biofilm was obviously changed by berberine and amylmetacresol. 512 µg/mL berberine and 0.002 33% amylmetacresol alone or in combination showed the survival rate was much higher than the injury rate, suggesting berberine and amylmetacresol had a low cytotoxicity. CONCLUSION: Berberine and amylmetacresol had synergism against E. faecalis, and the biological safety of the combination use was better.

[Mechanisms of cardioprotection induced by preconditioning after activation of MITOK(ATP) channel].

AIM: To determine mechanisms of cardioprotection induced by combination angiotensin-converting enzyme inhibitors (ACEI) with subthreshold preconditioning after activation of mitochondrial ATP-sensitive potassium (mitoK(ATP)) channel. METHODS: The Langendorff model of isolated rat heart was used. The time of the onset of uncoupling, the activities of sarcolemmal Na+/K+ -ATPase and Ca2+/Mg2+ -ATPase were measured. RESULTS: The subthreshold preconditioning (2 min of ischemia and 10 min reperfusion) or captopril (an ACEI) alone did not protect hearts against injury of sustained ischemia. However combination captopril with subthreshold preconditioning increased LVDP. Pretreatment hearts with mitoK(ATP) channel inhibitor 5-HD abolished the protection effect. Combination captopril with subthreshold preconditioning delayed the onset of uncoupling, and enhanced the activities of sarcolemmal Na+/K+ ATPase and Ca2+/Mg2+ -ATPase in ischemia/reperfusion hearts. But 5-HD cancelled these cardioprotection effects. CONCLUSION: Combination ACEI with subthreshold preconditioning delays the onset of cellular uncoupling induced by acute ischemia, and promotes the stability of sarcolemmal ion channels, in which activation of the mitoK(ATP) channels may be involved.

[Angiotensin-converting enzyme inhibitors potentiate subthreshold preconditioning through NO and mitoK(ATP) channel.].

The aim of the present study was to determine whether angiotensin-converting enzyme inhibitors (ACEI) could contribute to the protective effects of preconditioning, and to explore its underlying mechanism. The Langendorff model of isolated rat heart was used. Cardiac contractility and lactate dehydrogenase (LDH) in the coronary effluent were measured, and infarct area of hearts after 30 min of ischemia followed by 120 min of reperfusion was analyzed. We found that: (1) The subthreshold preconditioning (2 min of ischemia and 10 min of reperfusion), captopril (an ACEI with sulfhydryl groups) or perindoprilate (an ACEI without sulfhydryl groups) alone did not protect the hearts from being injured by 30 min of ischemia and 120 min of reperfusion. (2) However, the combination of captopril or perindoprilate with subthreshold preconditioning could decrease left ventricular end-diastolic pressure (LVEDP), increase left ventricular developed pressure (LVDP) and coronary flow compared with the subthreshold preconditioned group. The combination treatments also inhibited the release of LDH from ischemia/reperfusion hearts, and reduced the infarct area in ischemic heart after 2 h of reperfusion (P<0.05). (3) By using NOS inhibitor L-NAME (100 mumol/L) before combined administration of ACEI with subthreshold preconditioning, the protection effect triggered by the combination treatment was significantly reduced. Pretreatment of the hearts with mitochondrial ATP-sensitive potassium (mitoK(ATP)) channel inhibitor 5-HD (100 mumol/L) also abolished the protection effect (P<0.05). (4) Subthreshold preconditioning, captopril or perindoprilate alone could enhance the NO content in coronary effluent (P<0.05), but the combination of captopril or perindoprilate with subthreshold preconditioning could further augment the NO content compared with the subthreshold preconditioned group (P<0.05). The results indicate that ACEIs with or without sulfhydryl groups may potentiate the subthreshold preconditioning to trigger cardiac protection effect against the ischemia/reperfusion injury. This protection effect in the heart is possibly mediated by the generation of NO and the activation of mitoK(ATP) channel.