[粒细胞集落刺激因子通过Janus激酶2/信号转导子和转录激活子信号转导途径减轻冠状动脉微栓塞大鼠的心肌细胞凋亡]

[Granulocyte colony stimulating factor attenuated myocardial apoptosis via Janus kinase 2/signal transducer and activator of transcription signal transduction pathway in rats with coronary microembolization].

作者信息

Zhang Fei-Long, Chen Liang-Long, Li Shu-Mei, Wang Wei-Wei

机构信息

Department of Cardiology, Affiliated Union Hospital of Fujian Medical University, Fuzhou 350001, China.

出版信息

Zhonghua Xin Xue Guan Bing Za Zhi. 2008 Mar;36(3):254-9.

PMID:19099985

Abstract

OBJECTIVE

To investigate the effects of granulocyte colony stimulating factor (G-CSF) on myocardial apoptosis following coronary microembolization (CME) and possible role of Janus kinase/singnal transducer and activator of transcription (JAK/STAT) pathway in this process.

METHODS

A total of 92 male Sprague Dawley rats were randomized into CME (n = 24), G-CSF (100 microg x kg(-1) x d(-1) i.p. 2 hours post CME for 5 days, n = 24), JAK2 inhibitor AG490 (G-CSF plus AG490, 5 mg x kg(-1) x d(-1) i.p. 2 hours post CME for 5 days, n = 24), all rats received left ventricular injection of homologous microthrombotic particle suspension post clamping the ascending aorta. Sham-operated group (n = 20) served as control. The rats were sacrificed at day 3, 7, 14 and 28 after operation. The myocardial mRNA expressions of Bcl-2, Bax, Fas, FasL and GAPDH which was used as the intercomparison, were evaluated by real time PCR. The ratio of Bcl-2/Bax was compared. The protein expression of Caspase-3, cleaved PARP, t-JAK2, p-JAK2, t-STAT3 and p-STAT3 were detected by western blot. Myocardial apoptosis were examined by TUNEL staining.

RESULTS

Compared with Sham rats, the mRNA of Bcl-2, Bax, Fas and FasL significantly increased whereas the ratio of Bcl-2/Bax (0.28 +/- 0.04 vs. 2.98 +/- 0.49) significantly decreased and the protein expression of Caspase-3 (0.762 +/- 0.129 vs. 0.133 +/- 0.027), PARP (0.992 +/- 0.146 vs. 0.386 +/- 0.074) and the myocardial apoptosis index (17.2 +/- 1.9 vs. 1.2 +/- 0.6) significantly increased in CME hearts (all P < 0.05). rhG-CSF significantly attenuated CME induced changes and cotreatment with JAK2 inhibitor AG490 abolished the effects of rhG-CSF. The protein expressions of t-JAK2 and t-STAT3 among the groups were similar. P-JAK2 and p-STAT3 protein expressions were significantly increased in G-CSF group compared to other groups (P < 0.05).

CONCLUSION

G-CSF attenuated myocardial apoptosis induced by CME via JAK2/STAT3 pathway.

摘要

目的

探讨粒细胞集落刺激因子（G-CSF）对冠状动脉微栓塞（CME）后心肌细胞凋亡的影响以及Janus激酶/信号转导子和转录激活子（JAK/STAT）通路在此过程中的可能作用。

方法

将92只雄性Sprague Dawley大鼠随机分为CME组（n = 24）、G-CSF组（CME后2小时腹腔注射100μg·kg⁻¹·d⁻¹，共5天，n = 24）、JAK2抑制剂AG490组（G-CSF加AG490，CME后2小时腹腔注射5mg·kg⁻¹·d⁻¹，共5天，n = 24），所有大鼠在升主动脉夹闭后行左心室注射同源微血栓颗粒悬液。假手术组（n = 20）作为对照。术后第3、7、14和28天处死大鼠。通过实时PCR评估心肌中Bcl-2、Bax、Fas、FasL以及用作内参的GAPDH的mRNA表达。比较Bcl-2/Bax比值。通过蛋白质印迹法检测Caspase-3、裂解的PARP、总JAK2（t-JAK2）、磷酸化JAK2（p-JAK2）、总STAT3（t-STAT3）和磷酸化STAT3（p-STAT3）的蛋白表达。通过TUNEL染色检测心肌细胞凋亡。

结果

与假手术大鼠相比，CME组心脏中Bcl-2、Bax、Fas和FasL的mRNA显著增加，而Bcl-2/Bax比值（0.28±0.04 vs. 2.98±0.49）显著降低，Caspase-3（0.762±0.129 vs. 0.133±0.027）、PARP（0.992±0.146 vs. 0.386±0.074）的蛋白表达以及心肌凋亡指数（17.2±1.9 vs. 1.2±0.6）显著增加（均P < 0.05）。重组人G-CSF（rhG-CSF）显著减轻CME诱导的变化，与JAK2抑制剂AG490共同处理则消除了rhG-CSF的作用。各组间t-JAK2和t-STAT3的蛋白表达相似。与其他组相比，G-CSF组中p-JAK2和p-STAT3的蛋白表达显著增加（P < 0.05）。