摘要
目的:观察高血压大鼠动脉血管平滑肌细胞(VSMCs)内质网应激(ERS)相关因子葡萄糖调节蛋白78(GRP78)和C/EBP同源蛋白(CHOP)的表达、细胞凋亡率和血管中层厚度的变化,探讨ERS对高血压血管重构的影响。方法:将48只成年雄性SD大鼠随机等分为假手术对照组(对照组)和手术模型组,根据术后结束实验时间的不同,每组又分为3 d、7 d、14 d和28 d 4个亚组,每个亚组6只(n=6)。对大鼠测量血压后,应用免疫组化染色法检测主动脉VSMCs中GRP78和CHOP的表达。采用缺口末端标记法(TUNEL)检测细胞的凋亡;利用图像分析软件测量血管中层的厚度。结果:①模型组3 d、7 d、14 d和28 d亚组的平均动脉压(MAP),分别为(141.90±9.01)、(150.42±6.29)、(158.00±8.54)和(174.00±8.25)mmHg,均分别高于相应的对照组[(115.06±8.85)、(123.85±9.85)、(118.48±7.60)和(120.08±8.85)mmHg,P<0.05],且随着时间的延长,血压值逐渐升高。②除模型组3 d亚组外,模型组7 d、14 d和28 d亚组GRP78的表达(A值分别为0.60±0.04、0.85±0.06和0.55±0.06),均显著高于相应的对照组(A值分别为0.47±0.01、0.47±0.03和0.47±0.02,P<0.01),于术后14 d达到最高值。③模型组14 d、28 d亚组CHOP的表达(A值分别为0.48±0.04和0.57±0.05)显著高于相应的对照组(A值分别为0.40±0.02和0.40±0.01,P<0.01),于术后28 d达到最高值;模型组3 d和7 d亚组(A值分别为0.41±0.05和0.41±0.04)与相应的对照组(A值分别为0.39±0.03和0.39±0.03)比较无明显差异。④模型组3 d、7 d、14 d和28 d亚组VSMCs的凋亡率分别为(18.20±0.03)%、(12.00±0.03)%、(6.60±0.02)%和(2.30±0.02)%,与相应的对照组[分别为(21.40±0.04)%、(20.90±0.04)%、(20.50±0.04)%和(21.30±0.04)%]比较有非常显著性差异(P<0.01)。⑤模型组除3 d和7 d亚组血管中层的厚度与相应的对照组比较无明显差异外,模型组14 d和28 d亚组血管中层的厚度[分别为(100.32±2.92)μm和(107.52±5.42)μm]与相应对照组血管中层的厚度[分别为(93.43±2.73)μm和(92.92±3.17)μm]比较有非常显著性差异(P<0.01)。模型组除3 d与7 d亚组中膜的厚度比较无差异外,其余两亚组间中膜的厚度比较有非常显著性差异(P<0.01)。结论:在高血压发生早期,VSMCs中ERS反应的启动,可导致GRP78及CHOP的表达呈不对称增加,引起细胞凋亡率下降,这可能是血管重构发生的原因之一。
AIM： To clarify the effect of endoplasmic reticulum stress（ERS） on vascular remodeling induced by hypertension and to investigate the expression of the correlation factors： glucose-regulated protein of 78 kD（GRP78） and CAAT/enhancer binding protein homologous protein（CHOP）,apoptosis of aortic vascular smooth muscle cells（VSMCs） and the aortic media thickness of hypertensive rats.METHODS： Forty-eight Sprague Dawley（SD） adult rats were divided randomly into two groups： the sham operation group（control group） and the surgical model group.Each group was subdivided into 3-,7-,14-and 28-day subgroups according to the different time of ending the experiment after the surgery.Each subgroup had six rats.After blood pressure of rats was measured,expression of GRP78 and CHOP in aortic VSMCs was detected by immunohistochemistry staining,apoptosis was detected by TdT-mediated dUTP nick end labeling（TUNEL） and aortic media thickness was measured by image analyses software.RESULTS： Mean arterial blood pressure（MAP） of the 3-,7-,14-and 28-day subgroups in the model group was（141.90±9.01）,（150.42±6.29）,（158.00±8.54）,and（174.00±8.25） mmHg,respectively,and was significantly higher than MAP of the corresponding subgroups in the control group [（115.06±8.85）,（123.85±9.85）,（118.48±7.60）,（120.08±8.85） mmHg,respectively（P〈0.05）] in a time-dependent manner.Except for that of the 3-day subgroup,the expression of GRP78 of the 7-,14-,and 28-day subgroups in the model group,whose absorbance（A） value was 0.60±0.04,0.85±0.06,0.55±0.06 in turn,was significantly higher（P〈0.01）,with A value peaking on day 14 compared with that of the corresponding subgroups in the control group（0.47±0.01,0.47±0.03,0.47±0.02,respectively）.The expression of CHOP of 14-and 28-day subgroups in the model group,whose A value was 0.60±0.04,0.85±0.06,0.55±0.06,respectively,increased significantly（P〈0.01） compared with that of their corresponding subgroups in the control group（0.40±0.02,0.40±0.01,respectively） and the expression reached a peak on day 28 in the model group.No significant difference was observed in A value of the 3-and 7-day subgroups（0.41±0.05,0.41±0.04,respectively） in the model group compared with that of the corresponding subgroups in the control group（0.39±0.03,0.39±0.03,respectively）.Apoptosis rate of the vascular smooth muscle cells in the 3-,7-,14-and 28-day subgroups of the model group was（18.20±0.03）%,（12.00±0.03）%,（6.60±0.02）% and（2.30±0.02）%,respectively,and decreased significantly compared with that of the corresponding subgroups in the control group [（21.40±0.04）%,（20.90±0.04）%,（20.50±0.04）% and（21.30±0.04）%,respectively（P〈0.01].No significant difference was observed in media thickness of the 3-and 7-day subgroups in the model group compared with that of the corresponding subgroups in the control group.Media thickness of the 14-and 28-day subgroups in the model group was（100.32±2.92） μm,（107.52±5.42） μm,respectively,and increased significantly（P〈0.01） compared with that of the corresponding subgroups in the control group [（93.43±2.73） μm,（92.92±3.17） μm,respectively].In the model group no significant difference was observed in the media thickness between the 3-and 7-day subgroups but significant intergroup difference was observed in the media thickness（P〈0.01） between the other groups.CONCLUSION： ERS is induced in VSCMs during the early development of hypertension,which leads to the increase of mismatched expression of GRP78 and CHOP and a decrease in the rate of apoptosis.This may be one cause of vascular remodeling.
出处
《心脏杂志》
CAS
2011年第1期20-26,共7页
Chinese Heart Journal
基金
陕西省科学技术攻关课题(2005K13-G1-3)
作者简介
黄金燕，医师，硕士生Email：huangjy78@yahoo．cn
通讯作者：赵连友，主任医师，主要从事高血压发病机制及相关疾病防治的研究Email：zhaolyfmmu@yahoo．com．cn
