Fteita Dareen, Könönen Eija, Gürsoy Mervi, Ma Xiaochu, Sintim Herman O, Gürsoy Ulvi Kahraman
Department of Periodontology, Institute of Dentistry, University of Turku, FI-20520, Turku, Finland.
Department of Periodontology, Institute of Dentistry, University of Turku, FI-20520, Turku, Finland; Welfare Division, Oral Health Care, City of Turku, Turku, Finland.
Anaerobe. 2018 Dec;54:128-135. doi: 10.1016/j.anaerobe.2018.09.001. Epub 2018 Sep 3.
Quorum sensing (QS) signaling regulates the motility, adhesion, and biofilm formation of bacteria, and at the same time activates immune response in eukaryotic organisms. We recently demonstrated that the QS molecule, dihydroxy-2, 3-pentanedione (DPD), and its analogs significantly inhibit estradiol-regulated virulence of Prevotella aurantiaca, one of the four species in the Prevotella intermedia group. Here, we examined the combined effects of estradiol and QS signaling on 1) cytokine response of human gingival keratinocytes (HMK) against whole cell extract (WCE) of P. intermedia, Prevotella nigrescens, and Prevotella pallens, and 2) biofilm formation of these three Prevotella species. All experiments were performed in the presence or absence of estradiol, and with different QS molecules: DPD and its analogs (ethyl-DPD, butyl-DPD, and isobutyl-DPD). Concentrations of interleukin (IL)-1β, -6, and -8 were determined by the Luminex multiplex immunoassay, biofilm mass was quantitatively evaluated by measuring protein concentration via the Bradford method, and the microtopography of biofilms was assessed by scanning electron microscopy (SEM) imaging. Concentrations of IL-6 and IL-8 were elevated when HMK cells were incubated with estradiol and WCE of P. intermedia and P. nigrescens, but decreased when incubated with estradiol and WCE of P. pallens. Butyl-DPD neutralized the estradiol- and WCE-induced regulation of HMK interleukin expression and, at the same time, inhibited the biofilm formation of P. intermedia and P. nigrescens. SEM micrographs revealed a decrease in biofilm mass after application of butyl-DPD, which was most detectable among the P. intermedia ATCC 25611 and P. nigrescens ATCC 33563 and AHN 8293 strains. In conclusion, butyl-DPD analog is able to neutralize the WCE-induced epithelial cytokine response and, at the same time, to inhibit the biofilm formation of P. intermedia and P. nigrescens.
群体感应（QS）信号传导调节细菌的运动性、粘附性和生物膜形成，同时激活真核生物中的免疫反应。我们最近证明，群体感应分子二羟基-2,3-戊二酮（DPD）及其类似物能显著抑制中间普氏菌属四个物种之一的橙色普氏菌中雌二醇调节的毒力。在此，我们研究了雌二醇和群体感应信号对以下两方面的联合作用：1）人牙龈角质形成细胞（HMK）对中间普氏菌、变黑普氏菌和苍白普氏菌全细胞提取物（WCE）的细胞因子反应；2）这三种普氏菌属物种的生物膜形成。所有实验均在有或没有雌二醇的情况下进行，并使用不同的群体感应分子：DPD及其类似物（乙基-DPD、丁基-DPD和异丁基-DPD）。通过Luminex多重免疫测定法测定白细胞介素（IL）-1β、-6和-8的浓度，通过Bradford法测量蛋白质浓度对生物膜质量进行定量评估，并通过扫描电子显微镜（SEM）成像评估生物膜的微观结构。当HMK细胞与中间普氏菌和变黑普氏菌的雌二醇和WCE一起孵育时，IL-6和IL-8的浓度升高，但与苍白普氏菌的雌二醇和WCE一起孵育时浓度降低。丁基-DPD中和了雌二醇和WCE诱导的HMK白细胞介素表达调节，同时抑制了中间普氏菌和变黑普氏菌的生物膜形成。SEM显微照片显示，应用丁基-DPD后生物膜质量下降，这在中间普氏菌ATCC 25611、变黑普氏菌ATCC 33563和AHN 8293菌株中最为明显。总之，丁基-DPD类似物能够中和WCE诱导的上皮细胞因子反应，同时抑制中间普氏菌和变黑普氏菌的生物膜形成。
