Enhanced expression of Ca2+ channels by nerve growth factor and the v-src oncogene in rat phaeochromocytoma cells.
Enhanced expression of Ca2+ channels by nerve growth factor and the v-src oncogene in rat phaeochromocytoma cells.
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神经生长因子和 v-src 癌基因在大鼠嗜铬细胞瘤细胞中增强 Ca2 通道的表达。
DOI：
10.1113/jphysiol.1993.sp019679
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Rausch,DM
中科院分区：
文献类型：
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作者：
Lewis,DL;DeAizpurua,HJ;Rausch,DM
1.以大鼠嗜铬细胞瘤（PC 12）细胞为研究对象，探讨了神经元分化过程中钙通道类型的表达。通过用神经生长因子（NGF）处理或通过在遗传修饰的PC 12（PC 12/v-src）细胞中激活温度敏感性酪氨酸激酶（pp 60 v-src）来诱导神经元分化。PC 12细胞在NGF存在下形态学分化。当在激活pp 60 v-src激酶活性的37 ℃的允许温度下生长时，PC 12/v-src细胞在形态上分化，神经突延伸。相比之下，在40摄氏度的非允许温度下生长的PC 12/v-src细胞继续分裂，并且在形态上与对照PC 12细胞无法区分。2.使用Ba 2+作为电荷载体在PC 12细胞中测量全细胞Ca 2+电流。在保持电位为-80 mV的电流-电压曲线峰值处测得的Ba 2+电流为-0.28 +/-0.04 nA（平均值+/-S.E.M.）在对照PC 12细胞中为-1.25 +/-0.16 nA，而在NGF分化细胞中为-1.25 +/-0.16 nA。电流密度从对照PC 12细胞中的9.4 +/-0.7 pA/pF增加到NGF分化的PC 12细胞中的22.8 +/-2.4 pA/pF。在非允许温度40 ℃下生长的未分化PC 12/v-src细胞中的Ba 2+电流为-0.24 +/-0.04 nA，而在允许温度37 ℃下生长的分化PC 12/v-src细胞中的Ba 2+电流为-0.95 +/-0.16 nA。电流密度从在非允许温度40 ℃下生长的PC 12/v-src电池中的4.5 +/-0.5 pA/pF增加到在允许温度37 ℃下生长的PC 12/v-src电池中的13.3 +/-2.4 pA/pF。3.对于从-80 mV的保持电位在电流-电压曲线的峰值（10 mM Ba 2+中为0 mV）处测量的电流，确定Ba 2+电流对ω-芋螺毒素GVIA（ω-CgTX）的敏感性。在NGF分化的PC 12细胞中，10 μ M Ω-CgTx抑制了总Ba 2+电流的68.1 +/-3.2%，而对照细胞中为35.9 +/-4.1%。ω-CgTX-敏感电流的密度从对照细胞中的3.3 +/-0.4 pA/pF增加到NGF-分化细胞中的15.7 +/-2.0 pA/pF。在37摄氏度生长的分化PC 12/v-src细胞中，omega-CgTX抑制了总Ba 2+电流的52.2 +/-4.2%，而在40摄氏度生长的PC 12/v-src细胞中，这一比例为41.1 +/-3.8%。在v-src-介导的分化中，omega-CgTX-敏感电流的密度从1.9 +/-0.3增加到7.4 +/-2.0 pA/pF。（400字处删节）
1. Rat phaeochromocytoma (PC12) cells were used to investigate the expression of Ca2+ channel types during neuronal differentiation. Neuronal differentiation was induced by treatment with nerve growth factor (NGF) or by activation of a temperature‐sensitive tyrosine kinase (pp60v‐src) in genetically modified PC12 (PC12/v‐src) cells. PC12 cells differentiated morphologically in the presence of NGF. When grown at the permissive temperature of 37 degrees C which activates the kinase activity of pp60v‐src, PC12/v‐src cells differentiated morphologically with the extension of neurites. In contrast, PC12/v‐src cells grown at the non‐permissive temperature of 40 degrees C continued to divide and were morphologically indistinguishable from control PC12 cells. 2. Whole‐cell Ca2+ currents were measured in PC12 cells using Ba2+ as the charge carrier. Ba2+ currents measured at the peak of the current‐voltage curve from a holding potential of ‐80 mV were ‐0.28 +/‐ 0.04 nA (mean +/‐ S.E.M.) in control PC12 cells compared to ‐1.25 +/‐ 0.16 nA in NGF‐differentiated cells. The current density increased from 9.4 +/‐ 0.7 pA/pF in control PC12 cells to 22.8 +/‐ 2.4 pA/pF in NGF‐differentiated PC12 cells. Ba2+ currents were ‐0.24 +/‐ 0.04 nA in undifferentiated PC12/v‐src cells grown at the non‐permissive temperature of 40 degrees C compared to ‐0.95 +/‐ 0.16 nA in differentiated PC12/v‐src cells grown at the permissive temperature of 37 degrees C. The current density increased from 4.5 +/‐ 0.5 pA/pF in PC12/v‐src cells grown at the non‐permissive temperature of 40 degrees C to 13.3 +/‐ 2.4 pA/pF in PC12/v‐src cells grown at the permissive temperature of 37 degrees C. 3. The sensitivity of Ba2+ currents to omega‐conotoxin GVIA (omega‐CgTX) was determined for currents measured at the peak of the current‐voltage curve (0 mV in 10 mM Ba2+) from a holding potential of ‐80 mV. In NGF‐differentiated PC12 cells, 10 microM omega‐CgTx inhibited 68.1 +/‐ 3.2% of the total Ba2+ current compared to 35.9 +/‐ 4.1% in control cells. The density of the omega‐CgTX‐sensitive current increased from 3.3 +/‐ 0.4 pA/pF in control cells to 15.7 +/‐ 2.0 pA/pF in NGF‐differentiated cells. In differentiated PC12/v‐src cells grown at 37 degrees C, omega‐CgTX inhibited 52.2 +/‐ 4.2% of total Ba2+ current compared to 41.1 +/‐ 3.8% in PC12/v‐src cells grown at 40 degrees C. The density of the omega‐CgTX‐sensitive current increased from 1.9 +/‐ 0.3 to 7.4 +/‐ 2.0 pA/pF with v‐src‐mediated differentiation.(ABSTRACT TRUNCATED AT 400 WORDS)