目的:牙周炎是免疫性炎症性疾病,动脉粥样硬化(AS)和慢性肾脏病(CKD)是两种常见的全身性疾病。牙周炎促进AS和CKD,CKD与AS相互作用。本动物研究的目的是评估牙周炎和动脉粥样硬化分别存在时肾脏的变化以及牙周炎对动脉粥样硬化小鼠肾脏的退行性影响。
方法:将40只雄性Apoe-/-小鼠随机分为4组:对照组牙周炎(PD),AS和带PD的AS(AS+PD)。AS是由高脂肪饮食诱导的,并通过注射牙龈卟啉单胞菌脂多糖诱导PD(P。g-LPS)(内毒素悬浮液)进入小鼠上颌磨牙的颊侧。用显微CT扫描小鼠右上颌骨以评估牙槽骨丢失;主动脉组织用HE和Oil-RedO染色以评估动脉斑块形成;收集血清以检测血脂和血清肾功能参数的变化(血尿素氮[BUN],血清肌酐[Scr]);通过HE染色(肾小球和肾小管损伤评分)评估肾组织病理学变化,PAS染色(肾小球系膜基质指数)和Masson染色(肾脏纤维化面积百分比);qRT-PCR和ELISA用于评估肾脏炎性细胞因子(肿瘤坏死因子-α,白细胞介素-1β,中性粒细胞表面标志物Ly6G)。
结果:牙槽骨丢失量:PD组明显高于NC组(p<.05);AS+PD组高于PD组,差异无统计学意义。动脉粥样硬化斑块形成和血脂变化:AS组明显差于NC组(p<0.05),AS+PD组较AS组恶化。NC组实验动物肾组织相应的定性和定量分析结果逐渐恶化,PD组,AS组和AS+PD组依次加重。肾功能指标:AS组BUN含量高于PD组,差异无统计学意义;AS组Scr明显高于PD组(p<0.05);AS+PD组BUN和Scr含量高于AS组,差异无统计学意义。肾小球及肾小管毁伤评分:AS组均高于PD组,差异无统计学意义;AS+PD组明显高于AS组(p<.001)。肾小球系膜基质与肾小球面积的比值和肾脏纤维化面积的百分比:AS组明显高于PD组(p<0.001),AS+PD组明显高于AS组(p<.001)。炎性细胞因子的表达:AS组高于PD组,差异无统计学意义;AS+PD组明显高于AS组(p<0.05)。
结论:PD和AS均可加重肾组织的炎性应激,引起肾组织的损伤,而AS的炎症增加和损伤作用更强;PD可通过加重动脉粥样硬化小鼠肾脏炎症而促进动脉粥样硬化小鼠肾脏损伤;各组小鼠肾脏功能参数与肾脏炎症和组织病理学变化并不完全同步;PD可促进AS、AS小鼠的牙周炎症更严重,AS小鼠血脂的特殊变化与上述结果密切相关。
OBJECTIVE: Periodontitis is immune inflammatory disease, atherosclerosis (AS) and chronic kidney disease (CKD) are two common systemic diseases. Periodontitis promotes AS and CKD, and CKD interacts with AS. The objective of this animal
study was to evaluate the changes of kidney when periodontitis and atherosclerosis exist separately and the degenerative effects of periodontitis on the kidney in atherosclerotic mice.
METHODS: A total of 40 male Apoe-/- mice were randomly divided into four groups: control (NC), periodontitis (PD), AS and AS with PD (AS + PD). AS was induced by high-fat diet feeding, and PD was induced by injection of Porphyromonas gingivalis-Lipopolysaccharide (P.g-LPS) (endotoxin suspension) into the buccal side of mouse maxillary molars. The right maxilla of mice was scanned with micro-CT to evaluate alveolar bone loss; aortic tissue was stained with HE and Oil-Red O to evaluate arterial plaque formation; serum was collected to detect the changes of blood lipids and serum renal function parameters (blood urea nitrogen [BUN], serum creatinine [Scr]); renal histopathological changes were evaluated by HE staining (glomerular and tubular damage scores), PAS staining (glomerular Mesangial matrix index) and Masson staining (percentage of renal fibrosis area); qRT-PCR and ELISA were used to evaluate the expression of renal inflammatory cytokines (tumor necrosis factor-α, Interleukin-1β, neutrophil surface marker Ly6G).
RESULTS: The amount of alveolar bone loss: PD group was significantly higher than NC group (p < .05); AS + PD group was higher than PD group, the difference was not statistically significant. Atherosclerotic plaque formation and serum lipid changes: AS group were significantly worse than NC group (p < .05), and AS + PD group were worse than AS group. The results of the corresponding qualitative and quantitative analyses of kidney tissue in experimental animals gradually deteriorated in the NC group, PD group, AS group and AS + PD group and worsened sequentially. Renal function parameters: the content of BUN in AS group was higher than that in PD group, the difference was not statistically significant; Scr in AS group was significantly higher than that in PD group (p < .05); the contents of BUN and Scr in AS + PD group were higher than those in AS group, the difference was not statistically significant. Glomerular and tubular damage scores: AS group were higher than PD group, the difference was not statistically significant; AS + PD group were significantly higher than AS group (p < .001). The ratio of glomerular mesangial matrix to glomerular area and the percentage of renal fibrosis area: AS group were significantly higher than PD group (p < .001), and AS + PD group were significantly higher than AS group (p < .001). Expression of inflammatory cytokines: AS group was higher than PD group, the difference was not statistically significant; AS + PD group was significantly higher than AS group (p < .05).
CONCLUSIONS: Both PD and AS can aggravate the inflammatory stress of kidney tissue and cause the damage of kidney tissue, and the inflammatory increase and damage effect of AS is stronger; PD can promote kidney damage of atherosclerotic mice by aggravating the renal inflammation in atherosclerotic mice; renal function parameters were not completely synchronized with the changes of renal inflammation and histopathology in each group of mice; PD can promote AS, periodontal inflammation in mice with AS is more severe, and the special changes of blood lipids in mice with AS are closely related to the above results.