目的 观察大鼠心肌损伤后心肌组织环磷酸腺苷(cAMP)信号转导系统相关基因表达的变化及与心室重构、心功能变化的关系.方法雄性Wistar大鼠28只,体质量220～250 g.将大鼠按体质量随机分为急性心肌损伤组(AMD,n=10)、慢性心肌损伤组(CMD,n=9)和对照组(n=9).AMD和CMD组大鼠开胸,结扎左前降支,建立急性心肌损伤动物模型;对照组开胸后不做结扎.在术后24 h,处死AMD和对照组大鼠,CMD组大鼠8周后处死,大鼠处死前进行心脏超声和血流动力学检查.TUNEL法检测行心肌细胞凋亡,放射免疫法测量心肌组织中环磷酸腺苷(cAMP)水平,实时定量(RT)-PCR法测定受损心肌周围组织中诱导性cAMP早期阻遏物(ICER)mRNA、cAMP反应元件结合蛋白(CREB)mRNA、磷酸二酯酶3A(PDE3A)mRNA和bcl-2mRNA表达.结果心脏超声和血流动力学显示,AMD、CMD、对照组左心室舒张末内径(LVEDD)、舒张末压(LVEDP),左心室内压最大上升速率(+dp/dtmax)、下降速率(-dp/dtmax),左心室收缩压(LVSP)、射血分数(EF)、短轴缩短率(FS)组间比较差异有统计学意义(F值分别为285.9、196.8、83.2、80.4、54.9、196.6、95.2,P均＜0.01).其中AMD和CMD组,LVEDD[(7.03±0.28)、(8.20±0.27)mm]和LVEDP[(11.19±2.89)、(19.76±3.34)mmHg]明显高于对照组[(5.05±030)mm、(-5.62±3.01)mmHg,P均＜0.01];左室内压+dp/dtmax [(2964±449)、(2214±434)mmHg/s]和-dp/dtmax[(-2617±441)、(-1891±424)mmHg/s]、左室LVSP[(94.19±4.03)、(85.85±6.39)mmHg]、EF[(41.6±5.9)%、(35.9±4.1)%]和FS[(36.9±4.6)%、(23.1±4.9)%]均显著低于对照组[(4759±406)mmHg/s、(-4327±388)mmHg/s、(116.29±8.25)mmHg、(80.9±5.6)%、(53.1±4.3)%,P均＜0.01];与AMD组相比,CMD组上述改变更显著(P＜0.05或＜0.01).心肌凋亡指数、cAMP、ICER、CREB、PDE3A、bcl-2 mRNA表达,组问比较差异有统计学意义(F值分别为172.5、141.0、540.8、246.8、165.1、563.9,P均＜0.01).其中AMD和CMD组心肌凋亡指数[(32.8±4.2)%、(18.4±3.9)‰]和cAMP[(9.95±0.30)、(5.60±0.25)nmol/kg]明显高于对照组[(3.9±1.7)‰、(2.48±0.29)nmol/kg,P均＜0.01],CMD组低于AMD组(P＜0.01);ICER、CREB mRNA表达,AMD(1.434±0.093、5.70±0.50)和CMD组(0.942±0.076、2.64±0.51)明显高于对照组(0.154±0.063、1.08±0.35,P均＜0.01),AMD组高于CMD组(P＜0.01);PDE3A mRNA表达,AMD和CMD组(48.98±8.14、16.68±8.46)明显低于对照组(105.94±12.61,P均＜0.01),CMD组低于AMD组(P均＜0.01);bcl-2 mRNA表达AMD组(4.55±0.27)高于对照组(2.18±0.30,P＜0.01),CMD组(0.35±0.15)明显减少(P均＜0.01).结论慢性心肌损伤较急性心肌损伤心室重构更明显,cAMP信号转导系统过度激活后形成ICER和cAMP的自循环,致使ICER mRN升高,PDE3A mRN减少,可能是心肌损伤后心室重构和心力衰竭发生发展的原因之一.
目的 觀察大鼠心肌損傷後心肌組織環燐痠腺苷(cAMP)信號轉導繫統相關基因錶達的變化及與心室重構、心功能變化的關繫.方法雄性Wistar大鼠28隻,體質量220～250 g.將大鼠按體質量隨機分為急性心肌損傷組(AMD,n=10)、慢性心肌損傷組(CMD,n=9)和對照組(n=9).AMD和CMD組大鼠開胸,結扎左前降支,建立急性心肌損傷動物模型;對照組開胸後不做結扎.在術後24 h,處死AMD和對照組大鼠,CMD組大鼠8週後處死,大鼠處死前進行心髒超聲和血流動力學檢查.TUNEL法檢測行心肌細胞凋亡,放射免疫法測量心肌組織中環燐痠腺苷(cAMP)水平,實時定量(RT)-PCR法測定受損心肌週圍組織中誘導性cAMP早期阻遏物(ICER)mRNA、cAMP反應元件結閤蛋白(CREB)mRNA、燐痠二酯酶3A(PDE3A)mRNA和bcl-2mRNA錶達.結果心髒超聲和血流動力學顯示,AMD、CMD、對照組左心室舒張末內徑(LVEDD)、舒張末壓(LVEDP),左心室內壓最大上升速率(+dp/dtmax)、下降速率(-dp/dtmax),左心室收縮壓(LVSP)、射血分數(EF)、短軸縮短率(FS)組間比較差異有統計學意義(F值分彆為285.9、196.8、83.2、80.4、54.9、196.6、95.2,P均＜0.01).其中AMD和CMD組,LVEDD[(7.03±0.28)、(8.20±0.27)mm]和LVEDP[(11.19±2.89)、(19.76±3.34)mmHg]明顯高于對照組[(5.05±030)mm、(-5.62±3.01)mmHg,P均＜0.01];左室內壓+dp/dtmax [(2964±449)、(2214±434)mmHg/s]和-dp/dtmax[(-2617±441)、(-1891±424)mmHg/s]、左室LVSP[(94.19±4.03)、(85.85±6.39)mmHg]、EF[(41.6±5.9)%、(35.9±4.1)%]和FS[(36.9±4.6)%、(23.1±4.9)%]均顯著低于對照組[(4759±406)mmHg/s、(-4327±388)mmHg/s、(116.29±8.25)mmHg、(80.9±5.6)%、(53.1±4.3)%,P均＜0.01];與AMD組相比,CMD組上述改變更顯著(P＜0.05或＜0.01).心肌凋亡指數、cAMP、ICER、CREB、PDE3A、bcl-2 mRNA錶達,組問比較差異有統計學意義(F值分彆為172.5、141.0、540.8、246.8、165.1、563.9,P均＜0.01).其中AMD和CMD組心肌凋亡指數[(32.8±4.2)%、(18.4±3.9)‰]和cAMP[(9.95±0.30)、(5.60±0.25)nmol/kg]明顯高于對照組[(3.9±1.7)‰、(2.48±0.29)nmol/kg,P均＜0.01],CMD組低于AMD組(P＜0.01);ICER、CREB mRNA錶達,AMD(1.434±0.093、5.70±0.50)和CMD組(0.942±0.076、2.64±0.51)明顯高于對照組(0.154±0.063、1.08±0.35,P均＜0.01),AMD組高于CMD組(P＜0.01);PDE3A mRNA錶達,AMD和CMD組(48.98±8.14、16.68±8.46)明顯低于對照組(105.94±12.61,P均＜0.01),CMD組低于AMD組(P均＜0.01);bcl-2 mRNA錶達AMD組(4.55±0.27)高于對照組(2.18±0.30,P＜0.01),CMD組(0.35±0.15)明顯減少(P均＜0.01).結論慢性心肌損傷較急性心肌損傷心室重構更明顯,cAMP信號轉導繫統過度激活後形成ICER和cAMP的自循環,緻使ICER mRN升高,PDE3A mRN減少,可能是心肌損傷後心室重構和心力衰竭髮生髮展的原因之一.
목적 관찰대서심기손상후심기조직배린산선감(cAMP)신호전도계통상관기인표체적변화급여심실중구、심공능변화적관계.방법웅성Wistar대서28지,체질량220～250 g.장대서안체질량수궤분위급성심기손상조(AMD,n=10)、만성심기손상조(CMD,n=9)화대조조(n=9).AMD화CMD조대서개흉,결찰좌전강지,건립급성심기손상동물모형;대조조개흉후불주결찰.재술후24 h,처사AMD화대조조대서,CMD조대서8주후처사,대서처사전진행심장초성화혈류동역학검사.TUNEL법검측행심기세포조망,방사면역법측량심기조직중배린산선감(cAMP)수평,실시정량(RT)-PCR법측정수손심기주위조직중유도성cAMP조기조알물(ICER)mRNA、cAMP반응원건결합단백(CREB)mRNA、린산이지매3A(PDE3A)mRNA화bcl-2mRNA표체.결과심장초성화혈류동역학현시,AMD、CMD、대조조좌심실서장말내경(LVEDD)、서장말압(LVEDP),좌심실내압최대상승속솔(+dp/dtmax)、하강속솔(-dp/dtmax),좌심실수축압(LVSP)、사혈분수(EF)、단축축단솔(FS)조간비교차이유통계학의의(F치분별위285.9、196.8、83.2、80.4、54.9、196.6、95.2,P균＜0.01).기중AMD화CMD조,LVEDD[(7.03±0.28)、(8.20±0.27)mm]화LVEDP[(11.19±2.89)、(19.76±3.34)mmHg]명현고우대조조[(5.05±030)mm、(-5.62±3.01)mmHg,P균＜0.01];좌실내압+dp/dtmax [(2964±449)、(2214±434)mmHg/s]화-dp/dtmax[(-2617±441)、(-1891±424)mmHg/s]、좌실LVSP[(94.19±4.03)、(85.85±6.39)mmHg]、EF[(41.6±5.9)%、(35.9±4.1)%]화FS[(36.9±4.6)%、(23.1±4.9)%]균현저저우대조조[(4759±406)mmHg/s、(-4327±388)mmHg/s、(116.29±8.25)mmHg、(80.9±5.6)%、(53.1±4.3)%,P균＜0.01];여AMD조상비,CMD조상술개변경현저(P＜0.05혹＜0.01).심기조망지수、cAMP、ICER、CREB、PDE3A、bcl-2 mRNA표체,조문비교차이유통계학의의(F치분별위172.5、141.0、540.8、246.8、165.1、563.9,P균＜0.01).기중AMD화CMD조심기조망지수[(32.8±4.2)%、(18.4±3.9)‰]화cAMP[(9.95±0.30)、(5.60±0.25)nmol/kg]명현고우대조조[(3.9±1.7)‰、(2.48±0.29)nmol/kg,P균＜0.01],CMD조저우AMD조(P＜0.01);ICER、CREB mRNA표체,AMD(1.434±0.093、5.70±0.50)화CMD조(0.942±0.076、2.64±0.51)명현고우대조조(0.154±0.063、1.08±0.35,P균＜0.01),AMD조고우CMD조(P＜0.01);PDE3A mRNA표체,AMD화CMD조(48.98±8.14、16.68±8.46)명현저우대조조(105.94±12.61,P균＜0.01),CMD조저우AMD조(P균＜0.01);bcl-2 mRNA표체AMD조(4.55±0.27)고우대조조(2.18±0.30,P＜0.01),CMD조(0.35±0.15)명현감소(P균＜0.01).결론만성심기손상교급성심기손상심실중구경명현,cAMP신호전도계통과도격활후형성ICER화cAMP적자순배,치사ICER mRN승고,PDE3A mRN감소,가능시심기손상후심실중구화심력쇠갈발생발전적원인지일.
Objective To investigate the relationship between alteration of gene in cyclic adenosine monophosphate(cAMP) signal transduction system in rats after myocardial damage and changes of cardiac function and ventricular remodeling. Methods Twenty eight male Wistar rats weighing 220 g to 250 g were randomly divided into three groups: acute myocardial damage group(AMD, n = 10), chronic myocardial damage group (CMD,n = 9 ) and sham-operation group (control, n = 9). Animal model of acute myocardial damage was established by ligation of rats left coronary artery in the AMD and the CMD groups. Rats in control group were treated similarly, except that the coronary suture was not tied. Hemodynamics and echocardiography were measured before rats were sacrificed 24 hours after operation in control and AMD groups but those in CMD groups were sacrificed 8 weeks later. Cadiocyte apoptosis were estimated by TUNEL method, cAMP levels in heart were tested by radioimmunity and the mRNA expressions for inducible cAMP early repressor (ICER), cAMP response element binding protein (CREB), phosphodiesterase 3A (PDE3A) and bcl-2 were assayed by real-time quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Results The difference of left ventricular end diastolic diameter (LVEDD), left ventricular end diastolic pressure(LVEDP), maximal rising and falling rate of ventricular pressure,left ventricular systolic pressure (LVSP), eject fraction (EF) and fraction shortening (FS) were statistically significant among the three groups(F = 285.9, 196.8, 83.2, 80.4, 54.9, 196.6, 95.2, all P ＜ 0.01). LVEDD[(7.03 ±0.28), (8.20 ± 0.27)mm] and LVEDP[(11.19 ± 2.89), (19.76 ± 3.34)mmHg] in AMD and CMD groups were significantly increased, compared with those in control group[ (5.05 ± 0.30)mm, (- 5.62 ± 3.01 )mmHg, all P ＜0.01 ]. While maximal rising rate[ (2964 ± 449), (2214 ± 434)mmHg/s] and falling rate[(- 2617 ± 441),(- 1891± 424)mmHg/s] of left ventricular pressure, LVSP[ (94.19 ± 4.03), (85.85 ± 6.39)mmHg], EF[ (41.6 ±5.9)%, (35.9 ± 4.1 )%] and FS[ (36.9 ± 4.6)%, (23.1 ± 4.9)%] of left ventricular in the two groups were lower than those in control[(4759 ± 406)mmHg/s, (- 4327 ± 388)mmHg/s, (116.29 ± 8.25)mmHg, (80.9 ± 5.6)%,(53.1 ± 4.3)%, all P ＜ 0.01 ]. These changes in CMD group were more significant than those in AMD groups(P ＜0.05 or P ＜ 0.01 ). The difference of apoptotic index, cAMP and expression of ICER, CREB, PDE3A mRNA and bcl-2 mRNA were statistically significant among the three groups(F= 172.5, 141.0, 540.8, 246.8, 165.1, 563.9,all P＜ 0.01 ). Apoptotic index[ (32.8 ± 4.2)‰, (18.4 ± 3.9)‰] and cAMP in heart[ (9.95 ± 0.30), (5.60 ± 0.25)nmol/kg] in AMD and CMD groups were increased compared to control group[ (3.9 ± 1.7)‰, (2.48 ± 0.29)nmol/kg,all P ＜ 0.01 ], and those in CMD group were lower than in AMD group(all P ＜ 0.01 ). Expression of ICER mRNA (1.434 ± 0.093, 0.942 ± 0.076) and CREB mRNA(5.70 ± 0.50, 2.64 ± 0.51) in AMD and CMD groups were higher, and expression of PDE3A mRNA(48.98 ± 8.14, 16.68 ± 8.46) were lower than those in control group (0.154 ± 0.063, 1.08 ± 0.35, 105.94 ± 12.61, all P ＜ 0.01 ). The three genes in CMD group were fewer than those in AMD group(all P ＜ 0.01 ). bcl-2 mRNA was up regulated in AMD group(4.55 ± 0.27) and was down regulated in CMD group(0.35 ± 0.15) compared to control(2.18 ± 0.30, all P＜ 0.01). Conclusions There is PDE3A-ICER positive-feedback loop leading to myocyte apoptosis and heart failure after myocardial damage. The downregulation of PDE3A mRNA observed in chronic myocardial damage may play a causative role in the progression of ventricular remodeling and heart failure, in part, by inducing ICER mRNA and promoting cardiac myocyte dysfunction.
