摘要
目的:探究甲基丙二酸(MMA)在体外和体内的遗传毒性及其影响因素。方法:在体外研究中,分别用0、0.1、0.5、1、5、10 mmol/L MMA处理人脐静脉内皮细胞(HUVEC)不同时间(7 d或72 h)后,采取胞质分裂阻滞微核(CBMN)法检测微核(MN)、核质桥(NPB)和核芽(NB)千分率及基因组不稳定性(GIN)以判定遗传毒性;另通过CBMN实验检测MMA与丝裂霉素C、叶酸、同型半胱氨酸(Hcy)共同处理对HUVEC细胞的遗传毒性。在体内研究中,采用CF-1小鼠骨髓嗜多染红细胞微核实验验证MMA的遗传毒性。结果:与对照组及低浓度MMA(0.1~5 mmol/L)相比,10 mmol/L的MMA显著提升HUVEC细胞的MN和NPB千分率以及GIN频率(均为P<0.01),其遗传毒性来自MMA本身和酸性特征。10 mmol/L MMA和0.1μg/mL丝裂霉素C联合处理时,与二者分别单独处理相比,MN千分率、NB千分率和GIN频率均显著升高(P<0.05或P<0.01)。此外,10 mmol/L MMA显著降低100μmol/L Hcy诱发的MN千分率和GIN频率(P<0.05或P<0.01)。与正常叶酸组相比,短时间(72 h)叶酸缺乏对MMA的遗传毒性无显著影响,但是补充叶酸(45.4~90.7μmol/L)可降低MMA诱发的MN千分率、NPB千分率和GIN频率(P<0.05或P<0.01)。在CF-1小鼠体内实验中,与未经MMA处理的小鼠相比,高剂量MMA(200~400 mg/kg)处理组的MN千分率显著升高(P<0.01),提示MMA存在明显的非酸性依赖遗传毒性。结论:MMA存在内源性和酸性介导的遗传毒性,MMA与丝裂霉素C之间存在遗传毒性的协同效应,且MMA遗传毒性可被叶酸弱化,同时MMA也存在抗Hcy遗传毒性的作用。本研究为理解MMA遗传毒性及其干预方式提供了新的科学依据。
OBJECTIVE:This study was aimed to explore the genotoxicity of methylmalonic acid(MMA)based on in vitro and in vivo micronuclei assays,and potential factors influencing its genotoxicity.METHODS:For in vitro studies,human umbilical venous endothelial cells(HUVEC)were treated with 0,0.1,0.5,1,5,and 10 mmol/L MMA at different times(7 d or 72 h),and frequencies of micronuclei(MN),nucleoplasmic bridge(NPB)and nuclear bud(NB)and genomic instability(GIN)were assessed using by the cytokinesis-blocked micronucleus assay(CBMN).In addition,the CBMN assay was employed to detect the impact of mitomycin C,homocysteine(Hcy)and folic acid on the genotoxicity of MMA in HUVEC cells.For in vivo studies,the genotoxicity of MMA was verified by the bone marrow micronucleus assay in CF-1 mice.RESULTS:Compared with control and groups of low-concentration MMA(0.1-5 mmol/L),10 mmol/L MMA significantly increased rate of MN,NPB,and GIN in HUVEC(all P<0.01),and the genotoxicity was derived from the intrinsic toxicity and acidic nature of MMA.When HUVEC were treated with 10 mmol/L MMA and 0.1μg/mL mitomycin C together,rate of MN,NB and GIN were significantly elevated as compared to these of separately treated groups(P<0.05 and P<0.01).Furthermore,10 mmol/L MMA significantly reduced rate of MN and GIN induced by 100μmol/L Hcy(P<0.05 and P<0.01).Compared with control,short-term(72 h)folic acid deficiency had no significant effect on genotoxicity of MMA,but supplementation of folic acid(45.4-90.7μmol/L)significantly reduced rate of MN,NPB and GIN induced by 10 mmol/L MMA(P<0.05 and P<0.01).In CF-1 mice,high doses of MMA(200-400 mg/kg)exhibited significant acid-independent genotoxicity(MN rate)when compared with control(P<0.01).CONCLUSION:MMA showed intrinsic and acidmediated genotoxicity.Synergistic genotoxicity of MMA and mitomycin C was detected.Genotoxicity of MMA was mitigated by folic acid,and MMA ameliorated the genotoxicity of Hcy.This study provides new information for better understanding the genotoxicity of MMA and its intervention.
作者
李燏湘
朱银兰
吉秋月
李香
汪旭
周滔
郭锡汉
LI Yuxiang;ZHU Yinlan;JI Qiuyue;LI Xiang;WANG Xu;ZHOU Tao;GUO Xihan(College of Life Sciences,Yunnan Normal University,Kunming 650500,Yunnan;Taizhou Yeda Institute of Gene and Cell Therapy,Taizhou 318001,Zhejiang;College of Life Sciences,Yunnan University,Kunming 650500,Yunnan,China)
出处
《癌变·畸变·突变》
2025年第5期361-368,共8页
Carcinogenesis,Teratogenesis & Mutagenesis
基金
国家自然科学基金(32260148)
云南省教育厅科学研究基金(2024J0141)。
