Understanding the acid resistance mechanism of S.mutans is crucial for preventing dental caries.FtsZ is the core protein for cell division in bacteria that can polymerize into Z-rings and drive cytokinesis.Our previou...Understanding the acid resistance mechanism of S.mutans is crucial for preventing dental caries.FtsZ is the core protein for cell division in bacteria that can polymerize into Z-rings and drive cytokinesis.Our previous study revealed that the FtsZ in S.mutans(SmFtsZ) has higher self-assembly and GTPase activity under acidic stress,which may be responsible for acid resistance and ca riogenesis of S.mutans.However,the functional structure mechanism of SmFtsZ under low pH conditions is still unclear.Here,we further reported the crystal structure of S.mutans FtsZ,revealing a unique lateral interface.Through protein polymerization and GTPase activity assay,we experimentally demonstrated that the mutation of Arg68 on this lateral interface significantly reduced the functional activity of FtsZ in an acidic environment.The phenotype assay and rat caries model further showed that the mutation of Arg68 effectively inhibited the acid resistance of S.mutans and the occurrence and progress of dental caries in vivo.By employing a molecular dynamics simulation analysis,we conclude that the mutation of Arg68 disrupts the conformation change necessary for SmFtsZ polymerization under acidic conditions.Our study proposes a novel mechanism to maintain FtsZ function in bacteria and could be a potential target for antimicrobial drugs to inhibit the growth of S.mutans in acidic environments.展开更多
目的:探究三氧化矿物凝聚体(MTA)、iRoot BP Plus、富血小板纤维蛋白(PRF)联合MTA三种生物活性支架在龋齿患者中的应用效果,分析对患者年轻恒牙再生牙髓活力的影响。方法:选取2022年8月至2025年2月开封市口腔医院收治的102例龋齿引发年...目的:探究三氧化矿物凝聚体(MTA)、iRoot BP Plus、富血小板纤维蛋白(PRF)联合MTA三种生物活性支架在龋齿患者中的应用效果,分析对患者年轻恒牙再生牙髓活力的影响。方法:选取2022年8月至2025年2月开封市口腔医院收治的102例龋齿引发年轻恒牙急性牙髓炎患者,按照首次就诊顺序分为MTA组(34例35牙)、iRoot组(34例36牙)和PRF联合MTA组(34例36牙),分别采用MTA、iRoot BP Plus、PRF联合MTA支架材料进行牙髓再生性治疗。比较各组治疗后3个月根尖根管改善情况、牙髓活力及患牙恢复情况、治疗总有效率,记录治疗后不良反应发生情况。结果:RF联合MTA组根管长度差值、根管壁厚度差值、根尖闭合比例、牙髓活力阳性比例均大于MTA组和iRoot组,根尖周暗影比例低于MTA组和iRoot组(P<0.05);组牙体色泽异常、萌出高度增加比例比较无明显差异(P>0.05)。PRF联合MTA组、MTA组、iRoot组治疗总有效率分别为63.89%、34.29%、30.56%,PRF联合MTA组高于MTA组、iRoot组(P<0.05)。3组治疗不良反应发生率无统计学差异(P>0.05)。结论:在牙髓再生性治疗中,PRF联合MTA较其他生物活性支架能更好地诱导龋齿患者年轻恒牙牙根形成,保存牙髓活力,临床应用安全有效。展开更多
基金supported by the Beijing Natural Science Foundation:7222220National Natural Science Foundation of China (82001039)+2 种基金Research Foundation of Peking University School and Hospital of Stomatology:PKUSS20230117The Fundamental Research Funds for the Central UniversitiesYoung Elite Scientist Sponsorship Program by CAST (No.2019QNRC001 to Y.L.L)。
文摘Understanding the acid resistance mechanism of S.mutans is crucial for preventing dental caries.FtsZ is the core protein for cell division in bacteria that can polymerize into Z-rings and drive cytokinesis.Our previous study revealed that the FtsZ in S.mutans(SmFtsZ) has higher self-assembly and GTPase activity under acidic stress,which may be responsible for acid resistance and ca riogenesis of S.mutans.However,the functional structure mechanism of SmFtsZ under low pH conditions is still unclear.Here,we further reported the crystal structure of S.mutans FtsZ,revealing a unique lateral interface.Through protein polymerization and GTPase activity assay,we experimentally demonstrated that the mutation of Arg68 on this lateral interface significantly reduced the functional activity of FtsZ in an acidic environment.The phenotype assay and rat caries model further showed that the mutation of Arg68 effectively inhibited the acid resistance of S.mutans and the occurrence and progress of dental caries in vivo.By employing a molecular dynamics simulation analysis,we conclude that the mutation of Arg68 disrupts the conformation change necessary for SmFtsZ polymerization under acidic conditions.Our study proposes a novel mechanism to maintain FtsZ function in bacteria and could be a potential target for antimicrobial drugs to inhibit the growth of S.mutans in acidic environments.
文摘目的:探究三氧化矿物凝聚体(MTA)、iRoot BP Plus、富血小板纤维蛋白(PRF)联合MTA三种生物活性支架在龋齿患者中的应用效果,分析对患者年轻恒牙再生牙髓活力的影响。方法:选取2022年8月至2025年2月开封市口腔医院收治的102例龋齿引发年轻恒牙急性牙髓炎患者,按照首次就诊顺序分为MTA组(34例35牙)、iRoot组(34例36牙)和PRF联合MTA组(34例36牙),分别采用MTA、iRoot BP Plus、PRF联合MTA支架材料进行牙髓再生性治疗。比较各组治疗后3个月根尖根管改善情况、牙髓活力及患牙恢复情况、治疗总有效率,记录治疗后不良反应发生情况。结果:RF联合MTA组根管长度差值、根管壁厚度差值、根尖闭合比例、牙髓活力阳性比例均大于MTA组和iRoot组,根尖周暗影比例低于MTA组和iRoot组(P<0.05);组牙体色泽异常、萌出高度增加比例比较无明显差异(P>0.05)。PRF联合MTA组、MTA组、iRoot组治疗总有效率分别为63.89%、34.29%、30.56%,PRF联合MTA组高于MTA组、iRoot组(P<0.05)。3组治疗不良反应发生率无统计学差异(P>0.05)。结论:在牙髓再生性治疗中,PRF联合MTA较其他生物活性支架能更好地诱导龋齿患者年轻恒牙牙根形成,保存牙髓活力,临床应用安全有效。
