牙周炎对雌激素缺乏小鼠骨组织及肠道色氨酸代谢影响的研究  

Effects of periodontitis on bone and tryptophan metabolism of gut microbiota in estrogen-deficient mice

作　　者：魏媛 王南南[1] 王敏 钱俊 聂华 葛叡扬 廖文正 闫福华[1] Wei Yuan;Wang Nannan;Wang Min;Qian Jun;Nie Hua;Ge Ruiyang;Liao Wenzheng;Yan Fuhua(Department of Periodontology,Nanjing Stomatological Hospital,Affiliated Hospital of Medical School,Institute of Stomatology,Nanjing University,Nanjing 210008,China)

机构地区：[1]南京大学医学院附属口腔医院·南京市口腔医院牙周病科南京大学口腔医学研究所,南京210008

出　　处：《中华口腔医学杂志》2024年第4期354-363,共10页Chinese Journal of Stomatology

基　　金：国家自然科学基金(82270979);江苏省重点研发计划社会发展面上项目(BE2022670);江苏省医学学科重点实验室建设单位(JSDW202246)。

摘　　要：目的研究雌激素缺乏背景下,牙周炎对骨组织和肠道色氨酸代谢的影响。方法将32只雌性C57BL6/J小鼠根据随机数字表法随机分为4组(每组8只):假手术组(Sham组);假手术牙周炎组(Sham_Lig组);去卵巢组(Ovx组);去卵巢牙周炎组(Ovx_Lig组)。Sham_Lig组与Ovx_Lig组小鼠术后4周,以5-0号丝线结扎双侧上颌第二磨牙诱导牙周炎。丝线结扎8周后对4组小鼠实施安乐死,取材小鼠股骨、胫骨、下颌骨及颅骨样本行显微CT(micro-CT)扫描,并检测样本骨密度、骨体积分数(BV/TV)、骨小梁数量(Tb.N)、骨小梁厚度(Tb.Th)和骨小梁分离度(Tb.Sp)。收集4组小鼠盲肠内容物,利用16S rRNA基因测序检测肠道菌群的组成,通过液相色谱-质谱法检测肠道中的色氨酸及其代谢物的含量,并对肠道菌群相对丰度水平与色氨酸代谢物含量行相关性分析。结果Ovx_Lig组小鼠股骨骨密度[(82.23±3.97)mg/cm^(3)]、BV/TV[(9.25±1.37)%]和Tb.Th[(70.95±5.70)μm]均显著低于Ovx组[分别为(96.30±3.76)mg/cm^(3)(P=0.004)、(14.45±1.55)%(P=0.022)和(87.58±8.02)μm(P<0.001)]。肠道菌群基于Bray-Curtis距离的β多样性分析显示,Ovx_Lig组小鼠肠道菌群与Ovx组分群明显。线性判别分析效应量显示,另枝菌属为Ovx_Lig组显著差异菌属。Ovx_Lig组另枝菌属的相对丰度[(0.42±0.14)%]显著高于Ovx组[(0.17±0.05)%](t=4.45,P<0.001)。色氨酸代谢分析显示,Ovx_Lig组小鼠肠道内犬尿酸的含量[(531.12±158.60)ng/g]显著高于Ovx组[(400.42±57.96)ng/g](t=2.19,P=0.046),吲哚-3-甲醛的含量[(383.37±144.06)ng/g]显著低于Ovx组[(701.72±141.93)ng/g](t=4.45,P<0.001)。相关性分析显示另枝菌属的相对丰度与犬尿酸呈正相关(r=0.32,P=0.088),与吲哚-3-甲醛呈负相关(r=-0.32,P=0.088)。结论小鼠雌激素缺乏背景下,牙周炎可导致小鼠股骨骨质破坏,其机制可能与肠道另枝菌属及色氨酸代谢物犬尿酸和吲哚-3-甲醛有关。ObjectiveTo study the effects of periodontitis on bone and tryptophan metabolism of gut microbiota in the context of estrogen deficiency.MethodsThirty-two female C57BL6/J mice were randomly divided into four groups based on table of random numbers(n=8 in each group):Sham group,in which mice were given sham surgery;Sham_Lig group,in which mice were given sham surgery and were induced to periodontitis by ligating the bilateral maxillary second molars with 5-0 silk threads at the fourth week;Ovx group,in which mice were given bilateral ovariectomy;Ovx_Lig group,in which mice were given bilateral ovariectomy and were induced to periodontitis at the fourth week.After 8 weeks of ligation,the mice of 4 groups were euthanized for collecting the samples of femur,tibia,mandible and skull.Those samples were scanned by micro-CT to measure the bone mineral density(BMD),bone volume versus total volume ratio(BV/TV),trabecular number(Tb.N),trabecular thickness(Tb.Th)and trabecular spacing(Tb.Sp).The cecum contents of 4 groups of mice were collected for gut microbiota 16S rRNA gene sequencing.The tryptophan and its metabolites in intestinal tracts were detected by liquid chromatography-mass spectrometry.Pearson correlation analysis was performed to analyze the correlation between the abundance of gut microbiota and the content of tryptophan and its metabolites.ResultsFemur BMD[(82.23±3.97)mg/cm^(3)],BV/TV[(9.25±1.37)%]and Tb.Th[(70.95±5.70)μm]in Ovx_Lig group were significantly lower than Ovx group[(96.30±3.76)mg/cm^(3)(P=0.004);(14.45±1.55)%(P=0.022)and(87.58±8.02)μm(P<0.001),respectively].Theβ-diversity analysis of gut microbiota based on Bray-Curtis distance showed that samples of Ovx_Lig group and Ovx group were obviously grouped.Linear discriminant analysis effect size(LEfSe)showed that Alistipes was the representative genus in Ovx_Lig group.The relative abundance of Alistipes in Ovx_Lig group[(0.42±0.14)%]were significantly higher than that in Ovx group[(0.17±0.05)%](t=4.45,P<0.001).Tryptophan metabolism analysis

关 键 词：牙周炎 骨质疏松 绝经后 肠道菌群 骨代谢 色氨酸代谢 

分 类 号：R781.42[医药卫生—口腔医学]