中华放射医学与防护杂志
中華放射醫學與防護雜誌
중화방사의학여방호잡지
Chinese Journal of Radiological Medicine and Protection
2014年
9期
647-651
,共5页
徐凯%王静子%杨丹%张有为%薛利军%耿建%陈亚楠%郁红菊%褚晓源
徐凱%王靜子%楊丹%張有為%薛利軍%耿建%陳亞楠%鬱紅菊%褚曉源
서개%왕정자%양단%장유위%설리군%경건%진아남%욱홍국%저효원
表没食子儿茶素没食子酸酯%辐射损伤%甲基化%Rad23b%Ddit3
錶沒食子兒茶素沒食子痠酯%輻射損傷%甲基化%Rad23b%Ddit3
표몰식자인다소몰식자산지%복사손상%갑기화%Rad23b%Ddit3
Epigallocatechin gallate%Radiation damage%Methylation%Rad23b%Ddit3
目的探讨表没食子儿茶素没食子酸酯（EGCG）对0?5 Gy X射线引起的小鼠Rad23b和Ddit3基因启动子CpG岛甲基化及表达改变的逆转作用。方法 BALB/c雄性小鼠30只按随机数字表法均分为6组：对照组、单纯照射组、EGCG低剂量单纯给药组、EGCG高剂量单纯给药组、EGCG低剂量给药照射组、EGCG 高剂量给药照射组。照射方式为6 MV X 射线分次照射（0?05 Gy/d ×10 d）。小鼠在末次照射后2 h取血后处死，收集肾脏、肝脏、脾脏、脑及肺组织。采用BSP和Real-time PCR法检测各组小鼠外周血单个核细胞（PBMC）及各组织Rad23b和Ddit3启动子CpG岛的甲基化水平和 mRNA 表达变化。结果末次照射后2 h，与对照组比较，单纯照射组Rad23b在PBMC、肝脏、脾脏、脑和肺组织中甲基化水平均升高（ t ＝-20?19、-14?80、-12?05、-28?42、-12?58，P＜0?05），同时mRNA水平在PBMC、肝脏、脑和肺组织中表达降低（t＝25?25、17?43、11?53、22?85，P ＜0?05）；Ddit3甲基化水平在 PBMC、肝脏和肺组织中升高（t ＝-52?89、-20?31和-3?85，P ＜0?05），mRNA 水平在 PBMC 和肝脏中表达降低（t ＝11?89和16?52，P ＜0?05）。与单纯照射组比较，除脾脏中Rad23b外，不同浓度EGCG（10、20 mg/kg）给药照射组均能明显降低X射线引起的Rad23b和Ddit3启动子CpG岛高甲基化（t＝-13?39～7?99，P＜0?05），并诱导mRNA重新表达（t＝-34?02～-2?89，P＜0?05），且转录激活作用在高剂量给药照射组中更加明显。结论 EGCG作为逆转小剂量辐射损伤效应的天然药物，可能通过影响DNA甲基化来发挥作用。
目的探討錶沒食子兒茶素沒食子痠酯（EGCG）對0?5 Gy X射線引起的小鼠Rad23b和Ddit3基因啟動子CpG島甲基化及錶達改變的逆轉作用。方法 BALB/c雄性小鼠30隻按隨機數字錶法均分為6組：對照組、單純照射組、EGCG低劑量單純給藥組、EGCG高劑量單純給藥組、EGCG低劑量給藥照射組、EGCG 高劑量給藥照射組。照射方式為6 MV X 射線分次照射（0?05 Gy/d ×10 d）。小鼠在末次照射後2 h取血後處死，收集腎髒、肝髒、脾髒、腦及肺組織。採用BSP和Real-time PCR法檢測各組小鼠外週血單箇覈細胞（PBMC）及各組織Rad23b和Ddit3啟動子CpG島的甲基化水平和 mRNA 錶達變化。結果末次照射後2 h，與對照組比較，單純照射組Rad23b在PBMC、肝髒、脾髒、腦和肺組織中甲基化水平均升高（ t ＝-20?19、-14?80、-12?05、-28?42、-12?58，P＜0?05），同時mRNA水平在PBMC、肝髒、腦和肺組織中錶達降低（t＝25?25、17?43、11?53、22?85，P ＜0?05）；Ddit3甲基化水平在 PBMC、肝髒和肺組織中升高（t ＝-52?89、-20?31和-3?85，P ＜0?05），mRNA 水平在 PBMC 和肝髒中錶達降低（t ＝11?89和16?52，P ＜0?05）。與單純照射組比較，除脾髒中Rad23b外，不同濃度EGCG（10、20 mg/kg）給藥照射組均能明顯降低X射線引起的Rad23b和Ddit3啟動子CpG島高甲基化（t＝-13?39～7?99，P＜0?05），併誘導mRNA重新錶達（t＝-34?02～-2?89，P＜0?05），且轉錄激活作用在高劑量給藥照射組中更加明顯。結論 EGCG作為逆轉小劑量輻射損傷效應的天然藥物，可能通過影響DNA甲基化來髮揮作用。
목적탐토표몰식자인다소몰식자산지（EGCG）대0?5 Gy X사선인기적소서Rad23b화Ddit3기인계동자CpG도갑기화급표체개변적역전작용。방법 BALB/c웅성소서30지안수궤수자표법균분위6조：대조조、단순조사조、EGCG저제량단순급약조、EGCG고제량단순급약조、EGCG저제량급약조사조、EGCG 고제량급약조사조。조사방식위6 MV X 사선분차조사（0?05 Gy/d ×10 d）。소서재말차조사후2 h취혈후처사，수집신장、간장、비장、뇌급폐조직。채용BSP화Real-time PCR법검측각조소서외주혈단개핵세포（PBMC）급각조직Rad23b화Ddit3계동자CpG도적갑기화수평화 mRNA 표체변화。결과말차조사후2 h，여대조조비교，단순조사조Rad23b재PBMC、간장、비장、뇌화폐조직중갑기화수평균승고（ t ＝-20?19、-14?80、-12?05、-28?42、-12?58，P＜0?05），동시mRNA수평재PBMC、간장、뇌화폐조직중표체강저（t＝25?25、17?43、11?53、22?85，P ＜0?05）；Ddit3갑기화수평재 PBMC、간장화폐조직중승고（t ＝-52?89、-20?31화-3?85，P ＜0?05），mRNA 수평재 PBMC 화간장중표체강저（t ＝11?89화16?52，P ＜0?05）。여단순조사조비교，제비장중Rad23b외，불동농도EGCG（10、20 mg/kg）급약조사조균능명현강저X사선인기적Rad23b화Ddit3계동자CpG도고갑기화（t＝-13?39～7?99，P＜0?05），병유도mRNA중신표체（t＝-34?02～-2?89，P＜0?05），차전록격활작용재고제량급약조사조중경가명현。결론 EGCG작위역전소제량복사손상효응적천연약물，가능통과영향DNA갑기화래발휘작용。
Objective To investigate the role of epigallocatechin gallate ( EGCG) in reversing the CpG island methylation of Rad23b and Ddit3 gene promoter and its mRNA expression induced by 0?5 Gy X-rays. Methods Thirty BALB/c male mice were randomly divided into 6 groups: control group, irradiation group, low/high dose of EGCG group, low/high dose of EGCG with irradiation group. For the irradiation group, mice were fractionally exposed with 6 MV X-rays for 10 d (0?05 Gy/d × 10 d). 2 hours after the final irradiation, all mice were killed and such tissues as blood, kidney, liver, spleen, brain, and lung were collected. Methylation and expression levels of Rad23b and Ddit3 were measured by bisulfate sequencing primers ( BSP) and Real-time PCR, respectively. Results Compare to the control group, Rad23b was hypermethylated in PBMC, liver, spleen, brain and lung (t= -20?19, -14?80, -12?05,-28?42, -12?58, P<0?05) in the irradiation group. Meanwhile, its mRNA expression level was down-regulated in PBMC, liver, brain and lung (t=25?25, 17?43, 11?53, 22?85, P<0?05). Similarly, a significant hypermethylation change of Ddit3 was observed in PBMC, liver and lung after irradiation ( t=-52?89, -20?31, -3?85, P<0?05) so that the mRNA expression of Ddit3 decreased in PBMC and liver ( t = 11?89, 16?52, P < 0?05 ). Compared to the irradiation group, EGCG with different concentrations of 10, 20 mg/kg significantly reduced the methylation level of Rad23b and Ddit3 ( t =-13?39-7?99, P<0?05), and induced re-expression of mRNA (t= -34?02 - -2?89, P<0?05). This change was more notable in the irradiation group with the high dose of EGCG. Conclusions As a natural drug, EGCG may play an important role in affecting DNA methylation and hence protects DNA from radiation damage.
