茯苓酸对牙周炎大鼠牙槽骨吸收和炎症反应的影响及机制

Effects of pachymic acid on alveolar bone resorption and inflammatory response in rats with periodontitis

目的探讨茯苓酸(PA)对牙周炎大鼠牙槽骨吸收、炎症反应的影响及机制。方法将108只大鼠随机分为对照组(Control组)、模型组(Model组)、1 mg/kg茯苓酸(PA-L组)、5 mg/kg茯苓酸(PA-M组)、10 mg/kg茯苓酸(PA-H组)、10 mg/kg茯苓酸+10 mg/kg CXCL12(PA-H+CXCL12组),每组18只。除Control组外,其他各组均构建牙周炎模型。造模后,PA-L组、PA-M组、PA-H组分别经腹腔注射1、5、10 mg/kg茯苓酸,PA-H+CXCL12组经腹腔注射10 mg/kg茯苓酸+10 mg/kg CXCL12,Control组、Model组均经腹腔注射等量生理盐水,1天1次,连续给药4周。检测牙周指数[菌斑指数(PLI)评分、出血指数(SBI)评分];取各组大鼠腹主动脉血,ELISA法检测血清TNF-α、IL-6、IL-1β;用micro-CT测量牙槽嵴顶到釉牙骨质界的距离(CEJ-AC),观察牙槽骨吸收情况;HE染色后观察牙周组织病理变化;免疫组化法检测牙周组织中IL-1β、OPG蛋白表达;Western blotting法检测牙周组织中趋化因子12(CX-CL12)、趋化因子受体4(CXCR4)蛋白表达。结果与Control组比较,Model组牙龈上皮出现糜烂,有大量的炎症细胞浸润,组织水肿,结构损伤,排列紊乱,牙槽骨高度明显降低,可见大量骨吸收陷窝,PLI评分、SBI评分、CEJ-AC、TNF-α、IL-6、IL-1β及CXCL12、CXCR4蛋白表达高,OPG蛋白表达低(P均<0.05);与Model组比较,PA-L组、PA-M组、PA-H组牙周组织炎症逐渐减轻,结构损伤减轻,牙槽骨高度变浅,PLI评分、SBI评分、CEJ-AC、TNF-α、IL-6、IL-1β及CX-CL12、CXCR4蛋白表达依次降低,OPG蛋白表达依次升高(P均<0.05);与PA-H组比较,PA-H+CXCL12组牙周组织炎症加重,水肿明显,结构排列紊乱,损伤严重,PLI评分、SBI评分、CEJ-AC、TNF-α、IL-6、IL-1β、CXCL12、CXCR4蛋白表达高,OPG蛋白表达低(P均<0.05)。结论茯苓酸可通过调控CXCL12/CXCR4信号通路抑制牙周炎大鼠牙槽骨吸收,减轻炎症反应。

Objective To investigate the effects of pachymic acid(PA)on alveolar bone resorption and inflamma-tion in periodontitis rats and the mechanism.Methods A total of 108 rats were randomly divided into the control group,model group,1 mg/kg PA(PA-L group),5 mg/kg PA(PA-M group),10 mg/kg PA(PA-H group),10 mg/kg PA+10 mg/kg CXCL12(PA-H+CXCL12 group),with 18 rats in each.Periodontitis models were established in all groups except the Control group.After modeling,rats in the PA-L group,PA-M group and PA-H group were intraperitone-ally injected with 1,5 and 10 mg/kg PA,rats in the PA-H+CXCL12 group were intraperitoneally injected with 10 mg/kg PA+10 mg/kg CXCL12,and rats in the Control group and Model group were intraperitoneally injected with the same amount of normal saline.The drug was administered once a day for 4 weeks.Periodontal index[plaque index(PLI)score,bleeding index(SBI)score]were detected.Serum TNF-α,IL-6,and IL-1βwere detected by ELISA.The distance between alveolar crest and enamel cementum boundary(CEJ-AC)was measured by micro-CT to observe the resorption of alveolar bone.The pathological changes of periodontal tissues were observed by routine HE staining.The expression levels of IL-1βand OPG protein in periodontal tissues were detected by immunohistochemistry.The expression of CXC chemo-kine 12(CXCL12)and CXC chemokine receptor 4(CXCR4)protein in periodontal tissues was detected by Western blot-ting.Results Compared with the Control group,the gingival epithelium in the Model group showed erosion,a large number of inflammatory cell infiltration,tissue edema,structural damage,disarranged arrangement,significantly reduced alveolar bone height,a large number of bone resorption lacunae,high PLI score,SBI score,CEJ-AC,TNF-α,IL-6,IL-1β,CXCL12,and CXCR4 protein expression,and low OPG protein expression(all P<0.05).Compared with the Model group,periodontal tissue inflammation in the PA-L group,PA-M group and PA-H group gradually decreased,struc-tural damage was alleviated,alveolar bone height became shallow,PLI score,SBI score,CEJ-AC,TNF-α,IL-6,IL-1βand CXCL12 and CXCR4 protein expression decreased successively,and the expression of OPG protein increased succes-sively(all P<0.05).Compared with the PA-H group,PA-H+CXCL12 group had increased periodontal tissue inflamma-tion,obvious edema,disordered structure and serious injury,and increased protein expression levels of PLI score,SBI score,CEJ-AC,TNF-α,IL-6,IL-1β,CXCL12 and CXCR4,and decreased expression of OPG protein(all P<0.05).Conclusion PA can inhibit alveolar bone absorption and reduce inflammatory response in rats with periodontitis by regu-lating CXCL12/CXCR4 signaling pathway.