Neisseria lactamica在牙周病進展中所扮演的角色

Abstract

牙周病為好發於成年人的慢性疾病，盛行將近世界人口的一半 。相較於癌症、中風等疾病，牙周病導致死亡的情況很罕見，但有研究表明、罹患牙周病可能導致著嚴重的全身系統性疾病。嚴重的牙周病會使牙齒脫落，並影響溝通並導致咀嚼困難。因此、牙周病治療為當今健康保健與長期照護討論中，常被提及的重要議題。引起牙周病的原因中，口腔環境和細菌失衡，使生物膜累積，進而導致牙周病產生，誘導牙周組織損傷。因此，透過適時補充口腔益生菌，恢復口腔的微生物平衡而更有效的治療牙周病。 在實驗室先前的臨床檢體分析中，以第三代定序（Oxford Nanopore Technologies ）分析了牙周病患者與非牙周病患者在臨床上牙齦下牙菌斑的全基因序列。發現跟牙周病患相比，Neisseria lactamica（N. lactamica）在非牙周病患者的牙齦下牙菌斑中比牙周病患者高出40倍。N. lactamica 是革蘭氏陰性菌，在37℃微需氧的環境下生長。研究顯示，當Neisseria meningitidis（腦膜炎致病菌）對鼻咽上皮細胞引起發炎反應時，N. lactamica能有效抑制發炎，但是到目前為止，還沒有文章討論N. lactamica與牙周病這類發炎疾病的關係。因此本研究目的為了解N. lactamica是否能在牙周病中發揮保護的作用。 我們在處理抗生素卡納黴素 7天後的小鼠口中第一大臼齒和第二大臼齒之間放入多股縫合線（縫合線），誘導形成牙周病。24小時後在牙周病部位以兩種方式給予N. lactamica，分別是：在埋線部位注射一次，注射後第8天犧牲，其次、每天在繩結埋入部位塗抹N. lactamica，連續塗抹15天，觀察在不同給予方式的情形下，N. lactamica對牙周病的效果。我們收集小鼠牙齦溝液（gingival crevicular fluid，GCF），以Luminex® 200 Multiplex分析其中細胞因子的變化。另收集小鼠右上顎組織，進行組織病理學之研究與分析，觀察齒槽骨變化、嗜中性白血球浸潤和破骨細胞活化的情況。 結果顯示， 雖然N. lactamica沒有減緩齒槽骨流失，但降低了GCF中縫合線誘導的各細胞因子：Interferon gamma（IFN-γ）、Interleukin 1 beta（IL-1β）、Interleukin 6（IL-6）、Monocyte chemoattractant protein-1（MCP-1）和Tumor necrosis factor alpha（TNF-α），以及組織中的嗜中性白血球浸潤和破骨細胞活化， N. lactamica在牙周病中扮演降低發炎的角色，其中牽涉的機制仍有待釐清。

Periodontal disease is a chronic disease with high prevalence worldwide that affects more than half adults. Comparing to cancer or stroke, periodontal disease is rarely lethal. However, studies had shown that periodontal disease may lead to serious systemic diseases. Severe periodontal disease causes tooth loss that results in the difficulty of communication and mastication. Therefore, the improving treatment of periodontal disease is an important issue today. Periodontal disease is caused by an imbalance of the oral environment and microbial dysbiosis with biofilms accumulation and periodontal tissue damage. Therefore, restoring the microbial balance in oral cavity by daily supplement of oral probiotics may treat periodontal disease more effectively. We used the third-generation, the Oxford Nanopore Technologies sequencing system to analyze the whole genome sequence of clinical subgingival dental plaque from patients with or without periodontal disease. It was found that Neisseria Lactamica (N. lactamica) was 40 times higher in subgingival dental plaque from non-periodontal disease patients than periodontal disease patients. N. lactamica is a gram-negative bacterium and grows in a microaerophilic environment at 37°C. N. lactamica had proved effectively inhibits Neisseria meningitidis (meningitis-causing bacteria)-triggered inflammation in nasopharyngeal epithelial cells. So far, there is no article discuss the relationship of N. lactamica and periodontal disease. The purpose of this study was to determine whether N. lactamica could play protective roles in periodontal disease. We rapidly induced periodontal disease by placing ligature between the maxillary first and second molars of 7 days kanamycin-treated mice. Twenty-four hours later, N. lactamica was treated at the ligature-implanted site in two ways: first, injecting once at Day 8, and second, daily inoculating from Day 8 to Day 22, and evaluated the effects of different treated methods on N. lactamica-ameliorated periodontal disease. The mouse gingival crevicular fluid (GCF) was collected, and the changes of cytokines were analyzed by Luminex® 200 Multiplex analysis. In addition, the collected maxillary tissues were applied for histopathological experiments and analysis with the changes in alveolar bone, neutrophil infiltration and osteoclast activation. The results showed that N. lactamica had no effects on alveolar bone loss, but reduced ligature-induced cytokines: Interferon gamma (IFN-γ), Interleukin 1 beta (IL-1β), Interleukin 6 (IL-6), Monocyte chemoattractant protein-1 (MCP-1) and Tumour necrosis factor alpha (TNF-α) in GCF, as well as neutrophil infiltration and osteoclast activation in maxillary tissues. N. lactamica plays anti-inflammatory roles in periodontal disease, but the underling mechanisms are needed to uncover.