Pan J, Fukuda K, Kodama H, Sano M, Takahashi T, Makino S, Kato T, Manabe T, Hori S, Ogawa S
Department of Internal Medicine, Keio University, Tokyo, Japan.
Heart Vessels. 1998;13(4):199-208. doi: 10.1007/BF01745045.
Previously, we showed that the JAK/STAT pathway was activated in pressure-overloaded rat heart, and that angiotensin II was partially involved in this activation. The present study was designed to investigate whether gp130-mediated signaling is involved in this activation, and if so, which interleukin (IL)-6 family cytokine is involved. Pressure overload was produced by ligation of the abdominal aorta of Wistar rats or ICR mice. IP-Western blot was performed to detect tyrosine phosphorylation of STATs, gp130, and the association of gp130 with JAK kinases. The serum concentration of IL-6 was measured by enzyme-linked immunosorbent assay. Expression of IL-6, IL-11, leukemia inhibitory factor (LIF), ciliary neurotrophic factor (CNTF), oncostatin M (OSM), and cardiotrophin-1 (CT-1) mRNA was quantitated. After pressure overload, rapid phosphorylation of STAT1 and STAT3 was observed at 5 min, STAT1 was rephosphorylated at 60 min, and intense phosphorylation of STAT3 was observed at 60 min. Both the phosphorylation of gp130 and the association of gp130 with JAK1 and JAK2 were increased after pressure overload. IL-6 was significantly increased by two-fold in the pressure-overloaded rats. Only CT-1 mRNA expression could be detected by Northern blot, and it increased after pressure overload. Reverse transcription-polymerase chain reaction revealed that IL-6 mRNA expression was increased 9.5-fold. IL-11, LIF, CNTF, and OSM expression were unaffected by pressure overload. These results suggested that gp130-mediated signaling was involved in the pressure overload-induced activation of the JAK/STAT pathway, and that IL-6 and CT-1 might be involved in this activation.
此前，我们发现JAK/STAT信号通路在压力超负荷的大鼠心脏中被激活，且血管紧张素II部分参与了这一激活过程。本研究旨在探究gp130介导的信号传导是否参与这一激活过程，若参与，涉及哪种白细胞介素（IL）-6家族细胞因子。通过结扎Wistar大鼠或ICR小鼠的腹主动脉造成压力超负荷。采用免疫沉淀-蛋白质印迹法检测信号转导和转录激活因子（STATs）、gp130的酪氨酸磷酸化以及gp130与JAK激酶的结合情况。采用酶联免疫吸附测定法检测血清IL-6浓度。对IL-6、IL-11、白血病抑制因子（LIF）、睫状神经营养因子（CNTF）、制瘤素M（OSM）和心肌营养素-1（CT-1）mRNA的表达进行定量分析。压力超负荷后，5分钟时观察到STAT1和STAT3迅速磷酸化，60分钟时STAT1再次磷酸化，60分钟时观察到STAT3强烈磷酸化。压力超负荷后，gp130的磷酸化以及gp130与JAK1和JAK2的结合均增加。压力超负荷大鼠的IL-6显著增加了两倍。通过Northern印迹法仅能检测到CT-1 mRNA表达，且压力超负荷后其表达增加。逆转录-聚合酶链反应显示IL-6 mRNA表达增加了9.5倍。IL-11、LIF、CNTF和OSM的表达不受压力超负荷影响。这些结果表明，gp130介导的信号传导参与了压力超负荷诱导的JAK/STAT信号通路激活，且IL-6和CT-1可能参与了这一激活过程。
