Martin Kelsey, Mianecki Maxwell, Maglaras Victoria, Sheikh Asfandyar, Saleh Muhammad H A, Decker Ann M, Decker Joseph T
Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, 48109.
Department of Cariology, Restorative Sciences, and Endodontics, University of Michigan School of Dentistry, Ann Arbor, MI, 48109.
bioRxiv. 2024 Dec 3:2024.11.27.625678. doi: 10.1101/2024.11.27.625678.
The motivating premise of this study is to improve the treatment of periodontal disease by elucidating sex-specific mechanisms of periodontal disease progression. Men and women experience inflammation in fundamentally different ways and understanding the sex-specific biology leading to inflammation and bone loss in the periodontium will inevitably improve patient outcomes. We therefore examined clinical and immunological differences in the progression of periodontal disease using the ligature-induced periodontitis model. Periodontitis was induced in male and female C57BL/6j mice by tying a 5-0 silk suture around the left maxillary second molar. The ligature was left on for 7 or 21 days at which point maxillae were characterized for bone loss by μCT or immune infiltrate by flow cytometry. Neutrophil depletion was accomplished through systemic administration of a Ly6G antibody. Conditions were compared using two-way ANOVA with Tukey's multiple comparison correction from n≥5 animals. Ligature-induced periodontitis led to alveolar bone loss at both 7 and 21 days in both female and male mice. Males and females had approximately the same amount of linear bone loss 7 days post-ligature placement, while male mice had significantly more linear bone loss by day 21. Male mice had significantly more immune cells in their maxillae 7 days post ligature placement compared to female mice. Both male and female mice showed a shift in immune populations towards neutrophils, with no significant difference between males and females. Neutrophil counts were significantly elevated in male mice on day 7 but not day 21, while female mice did not have any statistically significant changes in neutrophil counts. Neutrophil depletion using a Ly6G antibody limited bone loss in male but not female mice relative to isotype antibody-treated controls. Analysis of single-cell sequencing data from human patients with periodontitis showed differences in neutrophil phenotypes that were also observed in a mouse model of periodontitis. Together, these data suggest a mechanistic role for neutrophil inflammation in sexual dimorphism in periodontitis.
本研究的驱动前提是通过阐明牙周疾病进展的性别特异性机制来改善牙周疾病的治疗。男性和女性经历炎症的方式存在根本差异，了解导致牙周组织炎症和骨质流失的性别特异性生物学特性将不可避免地改善患者的治疗效果。因此，我们使用结扎诱导的牙周炎模型研究了牙周疾病进展中的临床和免疫学差异。通过在雄性和雌性C57BL/6j小鼠的左上颌第二磨牙周围系上5-0丝线来诱导牙周炎。结扎持续7天或21天，此时通过μCT表征上颌骨的骨质流失情况，或通过流式细胞术分析免疫浸润情况。通过全身注射Ly6G抗体来实现中性粒细胞耗竭。使用双向方差分析及Tukey多重比较校正对n≥5只动物的条件进行比较。结扎诱导的牙周炎在雌性和雄性小鼠的7天和21天时均导致牙槽骨流失。在结扎放置后7天，雄性和雌性小鼠的线性骨质流失量大致相同，而到第21天时，雄性小鼠的线性骨质流失明显更多。与雌性小鼠相比，结扎放置后7天，雄性小鼠上颌骨中的免疫细胞明显更多。雄性和雌性小鼠的免疫群体均向中性粒细胞转变，雄性和雌性之间无显著差异。雄性小鼠在第7天中性粒细胞计数显著升高，但在第21天未升高，而雌性小鼠的中性粒细胞计数无任何统计学上的显著变化。相对于同型抗体处理的对照组，使用Ly6G抗体进行中性粒细胞耗竭可限制雄性小鼠而非雌性小鼠的骨质流失。对人类牙周炎患者的单细胞测序数据进行分析，结果显示中性粒细胞表型存在差异，这在牙周炎小鼠模型中也有观察到。总之，这些数据表明中性粒细胞炎症在牙周炎性别差异中具有机制性作用。
