Department of Craniofacial Diagnostics and Biosciences, Faculty of Dentistry, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur 50300, Malaysia.
Department of Medicine, Division of Hematology and Oncology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
Int J Mol Sci. 2024 Oct 14;25(20):11025. doi: 10.3390/ijms252011025.
is the major pathogenic bacteria found in the subgingival plaque of patients with periodontitis, which leads to neuroinflammation. The bacteria destroy periodontal tissue through virulence factors, which are retained in the bacteria's outer membrane vesicles (OMV). This study aimed to determine the real-time effect of an intraperitoneal injection of OMV on the production and expression of inflammatory markers and histopathological changes in adult zebrafishes' central nervous systems (CNS). Following the LD50 (21 µg of OMV), the zebrafish were injected intraperitoneally with 18 µg of OMVs, and the control group were injected with normal saline at seven different time points. Brains of experimental zebrafish were dissected at desired time points for colorimetric assays, ELISA, and histology. This study discovered that nitric oxide and PGE2 were significantly increased at 45 min, while IL-1β and IL-6 were expressed at subsequent 12 h and 24 h time points, respectively. Histopathological changes such as blood coagulation, astrocytosis, edema, spongiosis, and necrosis were observed between the 6hour and 24 h time points. The two apoptotic enzymes, caspases 3 and 9, were not expressed at any point. In summary, the OMV-induced neuroinflammatory responses and histopathological changes in adult zebrafish were time-point dependent. This study will enrich our understanding of the mechanism of OMVs in neuroinflammation in a zebrafish model, most especially the timing of the expression of inflammatory mediators in relation to observable changes in brain tissues.
牙龈卟啉单胞菌是导致牙周炎的主要致病菌，会引发神经炎症。该细菌通过毒力因子破坏牙周组织，这些毒力因子保留在细菌的外膜囊泡（OMV）中。本研究旨在确定腹腔注射 OMV 对成年斑马鱼中枢神经系统（CNS）中炎症标志物的产生和表达以及组织病理学变化的实时影响。在 LD50（21µg 的 OMV）之后，将斑马鱼腹腔内注射 18µg 的 OMV，对照组注射生理盐水，在七个不同时间点进行注射。在所需的时间点将实验性斑马鱼的大脑取出用于比色分析、ELISA 和组织学检查。本研究发现，45 分钟时一氧化氮和 PGE2 显著增加，而 IL-1β 和 IL-6 分别在随后的 12 小时和 24 小时时间点表达。在 6 小时和 24 小时时间点之间观察到血液凝固、星形胶质细胞增生、水肿、海绵状变性和坏死等组织病理学变化。两种凋亡酶 caspase 3 和 caspase 9 在任何时间点都没有表达。总之，OMV 诱导的成年斑马鱼神经炎症反应和组织病理学变化具有时间依赖性。本研究将丰富我们对 OMV 在斑马鱼模型中引发神经炎症的机制的理解，特别是炎症介质表达与脑组织中可观察到的变化之间的时间关系。
