Zhang Fei-Long, Chen Liang-Long, Li Shu-Mei, Wang Wei-Wei
Department of Cardiology, Affiliated Union Hospital of Fujian Medical University, Fuzhou 350001, China.
Zhonghua Xin Xue Guan Bing Za Zhi. 2008 Mar;36(3):254-9.
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.
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.
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).
G-CSF attenuated myocardial apoptosis induced by CME via JAK2/STAT3 pathway.
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。
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。
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）。
G-CSF通过JAK2/STAT3通路减轻CME诱导的心肌细胞凋亡。
