Desulfovibrio spp. survive within KB cells and modulate inflammatory responses

Desulfovibrio are sulfate‐reducing anaerobic gram‐negative rods that have been proposed as potential periodontopathogens. We investigated the capacity of Desulfovibrio to invade epithelial cells and induce cytokine secretion from these cells. Desulfovibrio strains were co‐cultured with KB cells and counts of intracellular bacteria evaluated up to 3 days after infection. Desulfovibrio desulfuricans and Desulfovibrio fairfieldensis were able to survive within epithelial cells. Intracytoplasmic location of both bacterial species was confirmed by confocal laser scanning microscopy and transmission electron microscopy. Invasion was sensitive to nocodazole, an inhibitor of microtubule polymerization, but not to cytochalasin D, a microfilament inhibitor, suggesting that microtubule rearrangements were involved in the internalization of Desulfovibrio strains by KB cells. Infection by Desulfovibrio resulted in increased production of IL‐6 and IL‐8 by KB cells. The ability of D. desulfuricans and D. fairfieldensis to survive within oral epithelial cells and to modulate the epithelial immune response may contribute to the initiation and progression of periodontal diseases.     

口腔黏膜上皮细胞和成纤维细胞的复合培养

目的 为癌前病变临床病理研究建立一种简便、迅速和有效的口腔黏膜上皮细胞和成纤维细胞复合培养的方法,实现体外模拟组织工程化口腔黏膜的发生发展。方法 用DispaseⅡ分离上皮和皮下组织,用KGM培养口腔黏膜上皮细胞。用细胞培养法和组织块培养法获取验用的口腔黏膜上皮细胞和成纤维细胞,并采用复合培养法对两种细胞进行共同培养。结果 用DispaseⅡ可成分地分离上皮和皮下组织。KGM可明显促进口腔黏膜上皮细胞的分裂繁殖。复合培养的HE染色切片显示薄层的结缔组织之上有方形的基底细胞、颗粒细胞和角化层。结论 KGM可明显促进口腔黏膜上皮细胞的分裂和成熟。采用组织培养法获取原代成纤维细胞是适合口腔黏膜取材等特点的有效方法。气液相培养的口腔黏膜下结缔组织可促进上皮细胞的分层和分化。     

Supernatants from oral epithelial cells and gingival fibroblasts modulate Human Immunodeficiency Virus type 1 promoter activation induced by periodontopathogens in monocytes/macrophages

Bacterial and host cell products during coinfections of Human Immunodeficiency Virus type 1‐positive (HIV‐1⁺) patients regulate HIV‐1 recrudescence in latently infected cells (e.g. T cells, monocytes/macrophages), impacting highly active antiretroviral therapy (HAART) failure and progression of acquired immunodeficiency syndrome. A high frequency of oral opportunistic infections (e.g. periodontitis) in HIV‐1⁺ patients has been demonstrated; however, their potential to impact HIV‐1 exacerbation is unclear. We sought to determine the ability of supernatants derived from oral epithelial cells (OKF4) and human gingival fibroblasts (Gin‐4) challenged with periodontal pathogens, to modulate the HIV‐1 promoter activation in monocytes/macrophages. BF24 monocytes/macrophages transfected with the HIV‐1 promoter driving the expression of chloramphenicol acetyltransferase (CAT) were stimulated with Porphyromonas gingivalis, Fusobacterium nucleatum, or Treponema denticola in the presence of supernatants from OKF4 or Gin4 cells either unstimulated or previously pulsed with bacteria. CAT levels were determined by enzyme‐linked immunosorbent assay and cytokine production was evaluated by Luminex beadlyte assays. OKF4 and Gin4 supernatants enhanced HIV‐1 promoter activation particularly related to F. nucleatum challenge. An additive effect was observed in HIV‐1 promoter activation when monocytes/macrophages were simultaneously stimulated with gingival cell supernatants and bacterial extracts. OKF4 cells produced higher levels of granulocyte–macrophage colony‐stimulating factor (GM‐CSF) and interleukins ‐6 and ‐8 in response to F. nucleatum and P. gingivalis. Preincubation of OKF4 supernatants with anti‐GM‐CSF reduced the additive effect in periodontopathogen‐induced HIV‐1 promoter activation. These results suggest that soluble mediators produced by gingival resident cells in response to periodontopathogens could contribute to HIV‐1 promoter activation in monocytes/macrophages, albeit this effect is most notable following direct stimulation of the cells with oral gram‐negative bacteria.     

Porphyromonas gingivalis survives within KB cells and modulates inflammatory response

BACKGROUND/AIMS: The purpose of the study was to investigate the intracellular survival of Porphyromonas gingivalis as a possible mechanism for maintaining periodontitis. METHODS: P. gingivalis strains, the strain ATCC 33277 and seven clinical isolates, were co-cultured with KB cells. The number of intracellular bacteria was determined up to 3 days after infection. In addition, the numbers of KB cells per well, the concentrations of the cytokines interleukin-1beta (IL-1beta), IL-6, IL-8 and tumour necrosis factor-alpha (TNF-alpha) and the arginine-specific amidolytic activity were measured. The 16S rRNA of P. gingivalis and the mRNA expression of IL-1beta, IL-6, IL-8, TNF-alpha and rgpA were also determined. RESULTS: All the P. gingivalis strains studied were able to survive within KB cells. In contrast to the reduced values of colony-forming units at day 3, equal and higher levels of 16S rRNA were seen in comparison to day 0. Arginine-specific amidolytic activity declined in all samples during infection. Expression of mRNA for rgpA was not found after infection of KB cells by P. gingivalis strains. IL-8 was detectable in all samples 2 days after infection with P. gingivalis strains. Principal components analysis underlined a correlation between the arginine-specific amidolytic activity 1 h after infection and both the released IL-8 and the mRNA expression of IL-8. Associations were found between the cultivable numbers of intracellular P. gingivalis and the mRNAs of IL-1, IL-6 and TNF-alpha at the day of infection. CONCLUSION: The results indicate survival of P. gingivalis within epithelial cells, possibly in a non-cultivable stage. Invasion into cells modulates the virulence properties of P. gingivalis as well as the inflammatory response of the cells.     

Granulocyte-macrophage colony-stimulating factor responses of oral epithelial cells to Candida albicans

Candida albicans is the principal fungal species responsible for oropharyngeal candidiasis, the most frequent opportunistic infection associated with immune deficiencies. Cytokines, such as granulocyte-macrophage colony-stimulating factor (GM-CSF), are important in the generation of effective immunity to C. albicans. The purposes of this investigation were to determine whether C. albicans triggers secretion of GM-CSF by oral epithelial cells in vitro and to investigate mechanisms of host cell-fungal interactions that trigger such responses. Oral epithelial cell lines as well as primary oral mucosal epithelial cells were challenged with stationary phase viable C. albicans, added to human cell cultures at varying yeast:oral cell ratios. Yeast were allowed to germinate for up to 48 h and supernatants were analyzed for GM-CSF by ELISA. Fixed organisms, germination-deficient mutants and separation of yeast from epithelial cells using cell culture inserts were used to assess the effects of viability, germination and physical contact, respectively, on the GM-CSF responses of these cells. Two out of three cell lines and three out of six primary cultures responded to C. albicans with an increase in GM-CSF secretion. GM-CSF responses were contact-dependent, strain-dependent, required yeast viability and were optimal when the yeast germinated into hyphae.     

In vivo effects of zoledronic acid on oral mucosal epithelial cells

Oral Diseases (2011) 17 , 291–297 Objective: Osteonecrosis of the jaw is a serious complication of bisphosphonate treatment for which the pathophysiology is unknown. The purpose of this study was to investigate whether in vivo zoledronic acid (ZA) induces alterations in cell proliferation, apoptosis, and matrix metalloproteinases (MMPs) expression in oral mucosal epithelial cells. Methods: One‐year‐old dogs were either untreated (control group) or given high doses of intravenous ZA (ZA group) for 3 months. The doses of ZA were equivalent to those given to cancer patients, yet were administered two times more frequently (every 2 weeks). Mucosal tissues were assessed immunohistochemically for cell proliferation (proliferating cell nuclear antigen, PCNA), matrix metalloproteinase (MMP) expression, and apoptosis (caspase 3 and TUNEL). Results: There were no significant differences between the groups with respect to PCNA, MMP‐2, MMP‐14, and TUNEL positive cells. However, the expression of MMP‐9 was significantly higher in the control group than in the ZA group (P < 0.05), whereas the expression of caspase 3 was significantly lower in the control group than in the ZA group (P < 0.05). Conclusion: These results suggest that high doses of ZA resulted in higher levels of apoptosis and lower levels of MMP‐9 in the oral epithelial cells supporting the idea of bisphosphonate treatment affects the oral mucosa.     

口腔黏膜上皮细胞与猪小肠黏膜下层体外复合培养的实验研究

目的探讨体外快速培养犬口腔黏膜上皮细胞（OMECs）及其与猪小肠黏膜下层（SIS）体外复合培养的方法,为组织工程化黏膜研究提供实验依据。方法采用混合酶消化法,于6%胎牛血清的上皮细胞无血清培养基（DKSFM）中培养OMECs,观察OMECs的形态特征、绘制生长曲线并进行细胞表面标志物检测。将第2代犬OMECs接种在SIS上,行苏木精-伊红染色、免疫组织化学染色、扫描电镜等观察OMECs在SIS上的生长状况。结果OMECs在DKSFM中生长良好,CK19细胞角蛋白免疫组化染色阳性。OMECs接种在SIS上呈单层生长,多角形,铺路石样排列,复合培养8 d呈多层生长。结论采用混合酶消化法,用含6%胎牛血清的DKSFM培养犬OMECs,方法简便,适合推广应用。SIS与OMECs有良好的相容性,可作为构建组织工程化黏膜的理想支架材料。     

Cytokine and chemokine response of bone cells after dentin challenge in vitro

OBJECTIVE: The aim of this study was to characterize the effects of dentin extracts on cytokine, chemokine and nitric oxide (NO) production by primary rat bone cells. STUDY DESIGN: Osteoblastic bone marrow cultures were exposed to particulate (D-part), non-particulate (D-n-part) and demineralized dentin extracts and evaluated for proliferative activity, cell morphology, alkaline phosphatase activity and bone-like nodule formation. Cytokine production was assessed by enzyme-linked immunosorbent assay and NO release by the Griess method. RESULTS: The dentin extracts did not affect osteoblast numbering. Conversely, they up regulated in a dose-dependent manner the production by the osteoblasts of the pro-inflammatory interleukin-1beta (IL-1beta), tumor necrosis factor-alpha, IL-6, cytokine-induced neutrophil chemoattractant-1, and of the anti-inflammatory cytokine, IL-10. The NO production was stimulated only by D-n-part. CONCLUSION: These results demonstrate that dentin induces the production of inflammatory cytokines by osteoblasts and suggest that pro-resorptive pathways might be stimulated when dentin molecules come into contact with bone cells during pathological processes associated with dentin and bone matrix dissolution.     

Oral and vaginal epithelial cell anti-Candida activity is acid labile and does not require live epithelial cells

BACKGROUND: Candida albicans is the causative agent of oral and vaginal candidiasis. Innate host defenses against C. albicans are important against each infection. Among these are oral and vaginal epithelial cells that have anti-Candida activity. The mechanism of action includes a requirement for cell contact with no role for soluble factors, and a putative role for carbohydrates based on the sensitivity of the activity to periodic acid. METHODS: Periodic acid treatment of epithelial cells as well as the property of partial resistance of antifungal activity to fixation was used to further dissect the mechanism of action. RESULTS: The results herein effectively now challenge a role for carbohydrates alone. Firstly, the putative carbohydrate(s) released into supernatants of periodic acid-treated epithelial cells could not compete with fresh epithelial cells for activity, and equivalent abrogation of activity was observed by periodic acid-treated cells irrespective of the amount of carbohydrate released. Instead, the similar abrogation of activity following treatment with other acids or when cocultured under acidic conditions suggests that the activity is acid-labile. Finally, while activity requires intact epithelial cells, it does not require live cells; activity was minimally affected by fixing epithelial cells prior to coculture where the majority of cells remained impermeable to Trypan blue but were defined as non-viable by positive nuclear staining with propidium iodide. CONCLUSION: These results suggest that antifungal activity is dependent on contact by intact, but not necessarily live, epithelial cells through an acid-labile mechanism.     

KGF对口腔黏膜上皮细胞中增殖相关基因PCNAmRNA的作用

目的：检测不同浓度角质细胞生长因子（KGF）对体外培养的口腔黏膜上皮细胞形态学及对上皮细胞增殖相关基因PCNAmRNA表达的影响。方法：体外培养的口腔黏膜上皮细胞加入含不同浓度KGF（0ng／mL,5ng／rnL,25ng／mL,50ng／mL）的D—KFSM,分别培养12h、24h、48h后观察细胞形态改变并用荧光实时定量检测各组细胞内增殖相关基因PCNAmRNA的表达。结果：①相同时间段实验组较对照组上皮细胞贴壁明显,培养48h实验3组（50ng／mL）较其他组细胞核仁明显;②12h时,实验组较对照组上皮细胞内PCNAmRNA表达增加,但各实验组间PCNAmRNA表达逐渐降低（P〈0．05）;③24h时实验组较对照组PCNAmRNA表达增加,但各实验组间无统计学差异护〉0．05）：④48h时,实验组较对照组PCNAmRNA表达增加,且呈剂量依赖性（P〈0．05）。结论：外源性KGF可上调口腔黏膜上皮细胞增殖相关基因PCNAmRNA的表达,且在不同时间段、不同浓度调控作用存在差异。     

Green tea catechins inhibit Porphyromonas gulae LPS-induced inflammatory responses in human gingival epithelial cells

ObjectivesTo determine the anti-inflammatory effects of green tea catechins in immortalized human gingival epithelial cells (Ca9-22) stimulated with Porphyromonas gulae lipopolysaccharide (LPS).MethodsCa9-22 cells were incubated with P. gulae LPS (10 μg/ml) with or without green tea catechins, epigallocatechin-3-gallate (EGCg), epigallocatechin (EGC), epicatechin-3-gallate (ECG), and epicatechin (EC) (each at 50 μM), for 6 or 24 h. Real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay were used to determine the induction of cyclooxygenase 2 (COX2), tumor necrosis factor alpha (TNF-ɑ), interleukin 6 (IL-6), and IL-8. Furthermore, the expression of toll-like receptors (TLRs) 2 and 4 was examined using real-time PCR and western blotting analysis, and phosphorylation of the p38 and ERK1/2 was examined using western blotting analysis.ResultsAt the mRNA and protein levels, EGCg, EGC, ECG, and EC were found to significantly inhibit COX2, TNF-ɑ, IL-6, and IL-8. Furthermore, the levels of ERK1/2 and p38 phosphorylation induced by P. gulae LPS were decreased following the addition of each of the catechins, as well as TLR2 and 4 mRNA and protein.ConclusionsThese findings indicate that green tea catechins are potent inhibitors of in?ammatory responses induced by P. gulae LPS, and may also be useful for prevention and/or attenuation of periodontitis.     

角质细胞生长因子对口腔黏膜上皮细胞凋亡的作用研究

目的 研究不同浓度角质细胞生长因子（KGF）对口腔黏膜上皮细胞凋亡的作用,为探讨KGF在口腔黏膜病发生发展中的作用提供依据。方法 将不同浓度的KGF（对照组0 ng·mL-1,实验1组5 ng·mL-1,实验2组25 ng·mL-1,实验3组50 ng·mL-1）分别加入体外培养的口腔黏膜上皮细胞,培养12、24、48 h后,倒置显微镜下观察其对细胞形态的影响,并用流式细胞仪检测细胞凋亡情况,荧光实时定量检测细胞凋亡相关基因Bcl-2、Bax mRNA的表达水平。结果 1）实验组较对照组细胞贴壁明显,且48 h时实验3组细胞核仁明显。2）培养48 h时,4组之间的细胞凋亡率、Bcl-2 mRNA、Bax mRNA表达均有统计学差异,随着KGF浓度的增加,细胞凋亡率和Bax mRNA表达逐渐降低,Bcl-2 mRNA表达逐渐升高（P<0.05）。结论 KGF可通过上调Bcl-2 mRNA和下调Bax mRNA的表达抑制上皮细胞的凋亡。     

Oral and vaginal epithelial cell anti‐Candida activity is acid labile and does not require live epithelial cells

Background: Candida albicans is the causative agent of oral and vaginal candidiasis. Innate host defenses against C. albicans are important against each infection. Among these are oral and vaginal epithelial cells that have anti‐Candida activity. The mechanism of action includes a requirement for cell contact with no role for soluble factors, and a putative role for carbohydrates based on the sensitivity of the activity to periodic acid. Methods: Periodic acid treatment of epithelial cells as well as the property of partial resistance of antifungal activity to fixation was used to further dissect the mechanism of action. Results: The results herein effectively now challenge a role for carbohydrates alone. Firstly, the putative carbohydrate(s) released into supernatants of periodic acid‐treated epithelial cells could not compete with fresh epithelial cells for activity, and equivalent abrogation of activity was observed by periodic acid‐treated cells irrespective of the amount of carbohydrate released. Instead, the similar abrogation of activity following treatment with other acids or when cocultured under acidic conditions suggests that the activity is acid‐labile. Finally, while activity requires intact epithelial cells, it does not require live cells; activity was minimally affected by fixing epithelial cells prior to coculture where the majority of cells remained impermeable to Trypan blue but were defined as non–viable by positive nuclear staining with propidium iodide. Conclusion: These results suggest that antifungal activity is dependent on contact by intact, but not necessarily live, epithelial cells through an acid‐labile mechanism.