目的 探讨肝脏组织磷脂酰肌醇3-激酶/蛋白激酶B(phosphatidylinosital 3-kinase/protein kinase B,PI3-K/AKT)信号通路在胎儿生长受限(fetal growth restriction,FGR)大鼠胰岛素敏感性降低中的作用. 方法 母鼠受孕后第1天始随机分为对照组和低蛋白组,各10只.低蛋白组孕鼠采用低蛋白饮食法(粗蛋白含量为8.00％)建立FGR仔鼠模型.测定对照组和低蛋白组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)空腹血浆葡萄糖和血清胰岛素,计算胰岛素抵抗指数及胰岛素敏感指数.实时荧光定量聚合酶链反应技术检测雄性仔鼠生后7、14、30、60及90 d肝脏组织胰岛素受体底物1、2和葡萄糖转运蛋白4 mRNA表达水平,采用Western印迹技术测定胰岛素受体底物1、PI3-K(p110β亚基)、AKT、磷酸化AKT蛋白表达水平.采用简单相关及多重线性回归分析肝脏组织中PI3-K/AKT信号通路关键分子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,差异有统计学意义(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60 d时FGR仔鼠空腹血浆葡萄糖开始高于对照组,直至90 d.FGR仔鼠空腹血清胰岛素和胰岛素抵抗指数30 d时显著高于对照组,持续至90 d.FGR仔鼠胰岛素敏感指数自30 d始即显著低于对照组,直至90 d,差异均有统计学意义(P均＜0.05).(3)与对照组相比,FGR仔鼠7d时胰岛素受体底物1、2 mRNA表达均显著降低(0.45±0.02与0.68±0.03,t=16.633,P＜0.05;0.34±0.10与0.70±0.19,t=4.864,P＜0.05),并持续至生后90 d(0.48±0.03与0.59±0.05,t=5.237,P＜0.05;0.49±0.20与0.70±0.11,t=2.253,P＜0.05)；胰岛素受体底物1、PI3-K及磷酸化AKT蛋白表达自14d时出现降低(0.22±0.05与0.52±0.11,t=7.024,P＜0.05;0.46±0.03与0.97±0.08,t=17.508,P＜0.05;0.62±0.10与0.89±0.08,t=6.100,P＜0.05),持续至生后90 d(1.11±0.08与1.32±0.14,t=3.714,P＜0.05;0.63±0.07与1.00±0.19,t=5.206,P＜0.05;0.28±0.03与0.45±0.10,t=4.880,P＜0.05).(4)FGR仔鼠磷酸化AKT蛋白表达量与胰岛素敏感指数呈正相关(r=0.704,P＜0.05)；磷酸化AKT蛋白表达量分别与空腹血浆葡萄糖、空腹血清胰岛素和胰岛素抵抗指数变化呈负相关(r分别为-0.609、-0.561和-0.577,P均＜0.05). 结论 FGR仔鼠肝脏组织中PI3-K/AKT信号通路中某些关键分子表达发生变化,可能参与了胰岛素抵抗的发生.
目的 探討肝髒組織燐脂酰肌醇3-激酶/蛋白激酶B(phosphatidylinosital 3-kinase/protein kinase B,PI3-K/AKT)信號通路在胎兒生長受限(fetal growth restriction,FGR)大鼠胰島素敏感性降低中的作用. 方法 母鼠受孕後第1天始隨機分為對照組和低蛋白組,各10隻.低蛋白組孕鼠採用低蛋白飲食法(粗蛋白含量為8.00％)建立FGR仔鼠模型.測定對照組和低蛋白組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)空腹血漿葡萄糖和血清胰島素,計算胰島素牴抗指數及胰島素敏感指數.實時熒光定量聚閤酶鏈反應技術檢測雄性仔鼠生後7、14、30、60及90 d肝髒組織胰島素受體底物1、2和葡萄糖轉運蛋白4 mRNA錶達水平,採用Western印跡技術測定胰島素受體底物1、PI3-K(p110β亞基)、AKT、燐痠化AKT蛋白錶達水平.採用簡單相關及多重線性迴歸分析肝髒組織中PI3-K/AKT信號通路關鍵分子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,差異有統計學意義(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60 d時FGR仔鼠空腹血漿葡萄糖開始高于對照組,直至90 d.FGR仔鼠空腹血清胰島素和胰島素牴抗指數30 d時顯著高于對照組,持續至90 d.FGR仔鼠胰島素敏感指數自30 d始即顯著低于對照組,直至90 d,差異均有統計學意義(P均＜0.05).(3)與對照組相比,FGR仔鼠7d時胰島素受體底物1、2 mRNA錶達均顯著降低(0.45±0.02與0.68±0.03,t=16.633,P＜0.05;0.34±0.10與0.70±0.19,t=4.864,P＜0.05),併持續至生後90 d(0.48±0.03與0.59±0.05,t=5.237,P＜0.05;0.49±0.20與0.70±0.11,t=2.253,P＜0.05)；胰島素受體底物1、PI3-K及燐痠化AKT蛋白錶達自14d時齣現降低(0.22±0.05與0.52±0.11,t=7.024,P＜0.05;0.46±0.03與0.97±0.08,t=17.508,P＜0.05;0.62±0.10與0.89±0.08,t=6.100,P＜0.05),持續至生後90 d(1.11±0.08與1.32±0.14,t=3.714,P＜0.05;0.63±0.07與1.00±0.19,t=5.206,P＜0.05;0.28±0.03與0.45±0.10,t=4.880,P＜0.05).(4)FGR仔鼠燐痠化AKT蛋白錶達量與胰島素敏感指數呈正相關(r=0.704,P＜0.05)；燐痠化AKT蛋白錶達量分彆與空腹血漿葡萄糖、空腹血清胰島素和胰島素牴抗指數變化呈負相關(r分彆為-0.609、-0.561和-0.577,P均＜0.05). 結論 FGR仔鼠肝髒組織中PI3-K/AKT信號通路中某些關鍵分子錶達髮生變化,可能參與瞭胰島素牴抗的髮生.
목적 탐토간장조직린지선기순3-격매/단백격매B(phosphatidylinosital 3-kinase/protein kinase B,PI3-K/AKT)신호통로재태인생장수한(fetal growth restriction,FGR)대서이도소민감성강저중적작용. 방법 모서수잉후제1천시수궤분위대조조화저단백조,각10지.저단백조잉서채용저단백음식법(조단백함량위8.00％)건립FGR자서모형.측정대조조화저단백조FGR자서생후3、7、14、30、60급90 d(매조매개시간점취웅성자서8지)공복혈장포도당화혈청이도소,계산이도소저항지수급이도소민감지수.실시형광정량취합매련반응기술검측웅성자서생후7、14、30、60급90 d간장조직이도소수체저물1、2화포도당전운단백4 mRNA표체수평,채용Western인적기술측정이도소수체저물1、PI3-K(p110β아기)、AKT、린산화AKT단백표체수평.채용간단상관급다중선성회귀분석간장조직중PI3-K/AKT신호통로관건분자표체개변여이도소민감성변화간적관계. 결과 (1)저단백조신생자서평균출생체중위(4.92±0.36)g,저우대조조적(6.43±0.59)g,차이유통계학의의(t=14.73,P＜0.05).저단백조자서중FGR발생솔위88.2％(97/110),기중웅성자서FGR발생솔위94.1％ (48/51).(2)생후60 d시FGR자서공복혈장포도당개시고우대조조,직지90 d.FGR자서공복혈청이도소화이도소저항지수30 d시현저고우대조조,지속지90 d.FGR자서이도소민감지수자30 d시즉현저저우대조조,직지90 d,차이균유통계학의의(P균＜0.05).(3)여대조조상비,FGR자서7d시이도소수체저물1、2 mRNA표체균현저강저(0.45±0.02여0.68±0.03,t=16.633,P＜0.05;0.34±0.10여0.70±0.19,t=4.864,P＜0.05),병지속지생후90 d(0.48±0.03여0.59±0.05,t=5.237,P＜0.05;0.49±0.20여0.70±0.11,t=2.253,P＜0.05)；이도소수체저물1、PI3-K급린산화AKT단백표체자14d시출현강저(0.22±0.05여0.52±0.11,t=7.024,P＜0.05;0.46±0.03여0.97±0.08,t=17.508,P＜0.05;0.62±0.10여0.89±0.08,t=6.100,P＜0.05),지속지생후90 d(1.11±0.08여1.32±0.14,t=3.714,P＜0.05;0.63±0.07여1.00±0.19,t=5.206,P＜0.05;0.28±0.03여0.45±0.10,t=4.880,P＜0.05).(4)FGR자서린산화AKT단백표체량여이도소민감지수정정상관(r=0.704,P＜0.05)；린산화AKT단백표체량분별여공복혈장포도당、공복혈청이도소화이도소저항지수변화정부상관(r분별위-0.609、-0.561화-0.577,P균＜0.05). 결론 FGR자서간장조직중PI3-K/AKT신호통로중모사관건분자표체발생변화,가능삼여료이도소저항적발생.
Objective To investigate the effect of liver phosphatidylinosital 3-kinase/protein kinase B (PI3-K/AKT) pathway on the decrease of insulin sensitivity in fetal growth restriction (FGR) rats.Methods Twenty pregnant female rats were randomly divided into two groups one day after conception:normal-protein group and low protein group (n=10,respectively).Rats in low-protein group was given low protein diet (8.00％ protein) during pregnancy to build FGR model,while normal-protein group was given normal protein diet (20.00％ protein).On day 3,7,14,30,60 and 90 after birth,fasting blood samples of 8 male FGR offsprings from low-protein group and 8 normal offsprings from normal-protein group were collected to measure fasting plasma glucose and insulin level.Then insulin resistance index and insulin sensitivity index were calculated to determine insulin sensitivity.On day 7,14,30,60 and 90 after birth,liver tissue of 8 male FGR and normal offsprings were collected,insulin receptor substrate 1,2 (IRS1/IRS2)and glucose transporter 4 (GLUT4) mRNA expression were measured by real-time fluorescence polymerase chain reaction and the protein expressions of IRS1,PI3-K (subunit p110β),and AKT and phosphorylated AKT (pAKT) were measured by Western blot.The relationships between the expression changes of key molecules of PI3-K/AKT pathway and insulin sensitivity were analyzed by correlation and multiple linear regression method.Results (1) Mean birth weight of baby rats in low-protein group was significantly lower than that of normal-protein group [(4.92±0.36) g vs (6.43±0.59) g,t=14.73,P＜0.05].The incidence of FGR in low-protein group was 88.2％ (97/110); and for male offsprings,it was 94.1 ％ (48/51).(2) Compared to normal offsprings,fasting plasma glucose levels of male FGR offsprings were significantly higher from the age of 60 days to 90 days.Insulin levels and insulin resistance index were significantly higher and insulin sensitivity index was lower from the age of 30 days to 90 days,P＜0.05 respectively.(3) Compared to normal offsprings,IRS1 (0.45 ± 0.02 vs 0.68± 0.03,t=16.633,P＜0.05) and IRS2 mRNA (0.34±0.10 vs 0.70±0.19,t=4.864,P＜0.05) expressions in FGR offsprings were lower from day 7 after birth to day 90 (0.48±0.03 vs 0.59±0.05,t=5.237,P＜0.05; 0.49±0.20 vs 0.70±0.11,t=2.253,P＜0.05).There were no differences in expressions of GIUT4 mRNA and AKT protein between two groups (P＞ 0.05).IRS1,PI3-K and pAKT protein expressions of FGR offsprings decreased significantly from day 14 (0.22±0.05 vs 0.52±0.11,t=7.024,P＜0.05; 0.46±0.03 vs 0.97±0.08,t=17.508,P＜0.05; 0.62±0.10 vs 0.89±0.08,t=6.100,P＜0.05) to day 90 (1.11±0.08 vs 1.32±0.14,t=3.714,P＜0.05; 0.63±0.07 vs 1.00±0.19,t=5.206,P＜0.05;0.28±0.03 vs 0.45±0.10,t=4.880,P＜0.05).(4) The pAKT protein expression level of FGR rats was positively correlated with insulin sensitivity index (r=0.704,P＜0.05) ; while negatively correlated to the level of fasting plasma glucose (r=-0.609,P＜0.05),fasting insulin (r=-0.561,P＜0.05) and insulin resistance index (r =0.577,P＜ 0.05).Conclusions The changes of some key molecules' expressions of PI3-K/AKT pathway in liver might be involved in the insulin resistance in FGR rats.
