中华围产医学杂志
中華圍產醫學雜誌
중화위산의학잡지
CHINESE JOURNAL OF PERINATAL MEDICINE
2012年
11期
683-688
,共6页
胎儿生长迟缓%胰岛素抗药性%PPARγ%DNA甲基化
胎兒生長遲緩%胰島素抗藥性%PPARγ%DNA甲基化
태인생장지완%이도소항약성%PPARγ%DNA갑기화
Fetal growth retadation%Insulin resistance%PPAR gamma%DNA methylation
目的 探讨肝脏过氧化物体增殖物激活受体γ (peroxisome proliferator-ativated receptorγ,PPARγ)基因启动子甲基化状态及其mRNA表达在胎儿生长受限(fetal growth restriction,FGR)大鼠胰岛素敏感性降低中的作用. 方法 20只雌鼠受孕后第1天随机分为对照组和低蛋白组,各10只.低蛋白组采用低蛋白(粗蛋白含量为8.00％)法建立FGR模型.测定对照组仔鼠和低蛋白组FGR仔鼠生后3、7、14、30、60及90 d(每组每个时间点取雄性仔鼠8只)空腹血浆血糖和空腹血清胰岛素,计算胰岛素抵抗指数及胰岛素敏感指数.采用甲基化特异性聚合酶链反应和逆转录-聚合酶链反应技术测定仔鼠生后7和90 d时肝脏组织PPARγ基因启动子甲基化水平及其mRNA表达情况.采用Pearson相关分析及秩和检验分析肝脏组织中PPARγ基因启动子甲基化及其mRNA表达改变与胰岛素敏感性变化间的关系. 结果 (1)低蛋白组新生仔鼠平均出生体重为(4.92±0.36)g,低于对照组的(6.43±0.59)g(t=14.73,P＜0.05).低蛋白组仔鼠中FGR发生率为88.2％(97/110),其中雄性仔鼠FGR发生率为94.1％(48/51).(2)生后90 d时FGR仔鼠空腹血浆血糖、血清胰岛素和胰岛素抵抗指数显著高于对照组[空腹血浆血糖:(8.95±1.83) mmol/L与(6.21±1.14) mmol/L,t=-3.291,P＜0.05;血清胰岛素:(59.57±9.89) mU/L与(36.10±7.32) mU/L,t=-4.916,P＜0.05；胰岛素抵抗指数:0.967±0.297与0.410±0.135,t=-4.472,P＜0.05)],而胰岛素敏感指数低于对照组仔鼠(-3.043±0.294与-2.172±0.354,t=4.774,P＜0.05).(3)生后7d时,对照组仔鼠与FGR仔鼠PPARγ基因启动子甲基化程度差异无统计学意义(0/8与2/8,Fisher精确概率法,P＞0.05),生后90 d时FGR仔鼠甲基化程度高于对照组仔鼠(8/8与2/8,Fisher精确概率法,P＜0.05).PPARγ基因完全甲基化仔鼠PPARγ基因mRNA相对表达水平最低(27.2±1.6),其次是甲基化与非甲基化共存组(47.3±33.0),完全非甲基化组最高(144.6±21.2),差异均有统计学意义(P均＜0.05).(4)FGR仔鼠生后90 d时PPARγ基因mRNA表达量分别与空腹血浆血糖、血清胰岛素和胰岛素抵抗指数呈负相关(r分别为-0.819、-0.906和-0.860,P均＜0.05),而与胰岛素敏感指数呈正相关(r=0.947,P＜0.05). 结论 PPARγ基因启动子区高甲基化可能抑制其基因转录,从而参与FGR大鼠胰岛素抵抗的发生.
目的 探討肝髒過氧化物體增殖物激活受體γ (peroxisome proliferator-ativated receptorγ,PPARγ)基因啟動子甲基化狀態及其mRNA錶達在胎兒生長受限(fetal growth restriction,FGR)大鼠胰島素敏感性降低中的作用. 方法 20隻雌鼠受孕後第1天隨機分為對照組和低蛋白組,各10隻.低蛋白組採用低蛋白(粗蛋白含量為8.00％)法建立FGR模型.測定對照組仔鼠和低蛋白組FGR仔鼠生後3、7、14、30、60及90 d(每組每箇時間點取雄性仔鼠8隻)空腹血漿血糖和空腹血清胰島素,計算胰島素牴抗指數及胰島素敏感指數.採用甲基化特異性聚閤酶鏈反應和逆轉錄-聚閤酶鏈反應技術測定仔鼠生後7和90 d時肝髒組織PPARγ基因啟動子甲基化水平及其mRNA錶達情況.採用Pearson相關分析及秩和檢驗分析肝髒組織中PPARγ基因啟動子甲基化及其mRNA錶達改變與胰島素敏感性變化間的關繫. 結果 (1)低蛋白組新生仔鼠平均齣生體重為(4.92±0.36)g,低于對照組的(6.43±0.59)g(t=14.73,P＜0.05).低蛋白組仔鼠中FGR髮生率為88.2％(97/110),其中雄性仔鼠FGR髮生率為94.1％(48/51).(2)生後90 d時FGR仔鼠空腹血漿血糖、血清胰島素和胰島素牴抗指數顯著高于對照組[空腹血漿血糖:(8.95±1.83) mmol/L與(6.21±1.14) mmol/L,t=-3.291,P＜0.05;血清胰島素:(59.57±9.89) mU/L與(36.10±7.32) mU/L,t=-4.916,P＜0.05；胰島素牴抗指數:0.967±0.297與0.410±0.135,t=-4.472,P＜0.05)],而胰島素敏感指數低于對照組仔鼠(-3.043±0.294與-2.172±0.354,t=4.774,P＜0.05).(3)生後7d時,對照組仔鼠與FGR仔鼠PPARγ基因啟動子甲基化程度差異無統計學意義(0/8與2/8,Fisher精確概率法,P＞0.05),生後90 d時FGR仔鼠甲基化程度高于對照組仔鼠(8/8與2/8,Fisher精確概率法,P＜0.05).PPARγ基因完全甲基化仔鼠PPARγ基因mRNA相對錶達水平最低(27.2±1.6),其次是甲基化與非甲基化共存組(47.3±33.0),完全非甲基化組最高(144.6±21.2),差異均有統計學意義(P均＜0.05).(4)FGR仔鼠生後90 d時PPARγ基因mRNA錶達量分彆與空腹血漿血糖、血清胰島素和胰島素牴抗指數呈負相關(r分彆為-0.819、-0.906和-0.860,P均＜0.05),而與胰島素敏感指數呈正相關(r=0.947,P＜0.05). 結論 PPARγ基因啟動子區高甲基化可能抑製其基因轉錄,從而參與FGR大鼠胰島素牴抗的髮生.
목적 탐토간장과양화물체증식물격활수체γ (peroxisome proliferator-ativated receptorγ,PPARγ)기인계동자갑기화상태급기mRNA표체재태인생장수한(fetal growth restriction,FGR)대서이도소민감성강저중적작용. 방법 20지자서수잉후제1천수궤분위대조조화저단백조,각10지.저단백조채용저단백(조단백함량위8.00％)법건립FGR모형.측정대조조자서화저단백조FGR자서생후3、7、14、30、60급90 d(매조매개시간점취웅성자서8지)공복혈장혈당화공복혈청이도소,계산이도소저항지수급이도소민감지수.채용갑기화특이성취합매련반응화역전록-취합매련반응기술측정자서생후7화90 d시간장조직PPARγ기인계동자갑기화수평급기mRNA표체정황.채용Pearson상관분석급질화검험분석간장조직중PPARγ기인계동자갑기화급기mRNA표체개변여이도소민감성변화간적관계. 결과 (1)저단백조신생자서평균출생체중위(4.92±0.36)g,저우대조조적(6.43±0.59)g(t=14.73,P＜0.05).저단백조자서중FGR발생솔위88.2％(97/110),기중웅성자서FGR발생솔위94.1％(48/51).(2)생후90 d시FGR자서공복혈장혈당、혈청이도소화이도소저항지수현저고우대조조[공복혈장혈당:(8.95±1.83) mmol/L여(6.21±1.14) mmol/L,t=-3.291,P＜0.05;혈청이도소:(59.57±9.89) mU/L여(36.10±7.32) mU/L,t=-4.916,P＜0.05；이도소저항지수:0.967±0.297여0.410±0.135,t=-4.472,P＜0.05)],이이도소민감지수저우대조조자서(-3.043±0.294여-2.172±0.354,t=4.774,P＜0.05).(3)생후7d시,대조조자서여FGR자서PPARγ기인계동자갑기화정도차이무통계학의의(0/8여2/8,Fisher정학개솔법,P＞0.05),생후90 d시FGR자서갑기화정도고우대조조자서(8/8여2/8,Fisher정학개솔법,P＜0.05).PPARγ기인완전갑기화자서PPARγ기인mRNA상대표체수평최저(27.2±1.6),기차시갑기화여비갑기화공존조(47.3±33.0),완전비갑기화조최고(144.6±21.2),차이균유통계학의의(P균＜0.05).(4)FGR자서생후90 d시PPARγ기인mRNA표체량분별여공복혈장혈당、혈청이도소화이도소저항지수정부상관(r분별위-0.819、-0.906화-0.860,P균＜0.05),이여이도소민감지수정정상관(r=0.947,P＜0.05). 결론 PPARγ기인계동자구고갑기화가능억제기기인전록,종이삼여FGR대서이도소저항적발생.
Objective To explore the effect of methylation of peroxisome proliferator-activated receptor γ(PPARy) gene promoter in liver and its mRNA expression changes on decreasing of insulin sensitivity in fetal growth restriction (FGR) rats.Methods Twenty pregnant rats were randomly divided into two groups on their first day of pregnancy:normal-protein group (NP) and low-protein group (LP),ten in each.During pregnancy the LP group rats were fed with low-protein diet (8.00％ protein),while the NP group rats were fed with normal-protein diet (20.00％ protein).The offspring rats were fed with standard feed after 21 days of birth.Male offsprings in NP group were as control offsprings,and male FGR offsprings in LP group ware as FGR offsprings.At day 3,7,14,30,60 and 90,fasting blood of offsprings was collected to measure fasting plasma glucose (FPG) and fasting insulin(FINS).Then insulin resistance index of homeostasis model assessment (HOMA-IR) and insulin sensitivity index (ISI) were calculated to evaluate insulin sensitivity.At day 7 and 90,liver tissue of male offsprings was collected to extract DNA and total RNA.The methylation level of PPARγ gene promoter and its mRNA expression were detected by methylation specific-polymerase chain reaction (MS-PCR) and reverse transcription-RCR,respectively.The relationships between methylation of PPARγ gene promoter and mRNA expression and insulin sensitivity were analyzed by Pearson correlation and nonparametric test method.Results (1) The mean offspring birth-weight of LP group was (4.92±0.36) g,which was lower than that [(6.43±0.59) g] of control group (t=14.73,P＜0.05).In LP group,the incidence of FGR offspring was 88.2％ (97/110) and the FGR incidence of male ones was 94.1％ (48/51).(2) At day 90,compared with control offsprings,FPG [(8.95±1.83) mmol/L vs (6.21±1.14) mmol/L,t=-3.291,P＜0.05],FINS [(59.57±9.89) mU/Lvs (36.10±7.32) mU/L,t=-4.916,P＜0.05] and HOMA-IR (0.967±0.297 vs 0.410±0.135,t=-4.472,P＜0.05) of FGR offsprings were significantly higher; while ISI of FGR offspring was lower than that of control offsprings (-3.043±0.294 vs -2.172±0.354,t=4.774,P＜0.05).(3) There was no significant difference in methylation degree of PPARγ gene promoter in liver between FGR and control offsprings at day 7 (0/8 vs 2/8,Fisher exact test,P＞0.05).The methylation degree of PPARγ gene promoter in liver in FGR offsprings was significantly higher than that of control offsprings at day 90 (8/8 vs 2/8,Fisher exact test,P＜0.05).Compared with control offsprings,PPARγ gene mRNA expression level of FGR offsprings decreased significantly at day 90 (4.3.07±7.51 vs 146.72± 40.66,t=7.09,P＜0.05).mRNA expression of PPARγ gene was the lowest in exhaustive methylation offsprings (27.2± 1.6),and then in partial methylation ones (47.3±33.0),the highest in no methylation ones (144.6 ± 21.2) (P＜0.05).(4) The correlation analysis showed that PPARγ mRNA expression level negatively correlated to the level of FPG (r=-0.819),FINS (r=-0.906) and HOMA-IR (r=-0.860),P＜0.05 respectively; but positively correlated to ISI level (r=0.947,P＜0.05).Conclusions Hypermethylation in promoter region of PPARγ gene might inhibit gene transcription,and be involved in the occurrence of insulin resistance in FGR rats.
