Activation of TRPC6 channels contributes to ( )-conocarpan-induced apoptotic cell death in HK-2 cells
Activation of TRPC6 channels contributes to ( )-conocarpan-induced apoptotic cell death in HK-2 cells
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TRPC6 通道的激活有助于 ( )-conocarpan 诱导 HK-2 细胞凋亡
DOI：
10.1016/j.fct.2019.04.061
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发表时间：
2019
影响因子：
4.3
通讯作者：
Cao Zhengyu
中科院分区：
文献类型：
--
作者：
Yang Guoling;Ma Hui;Wu Yanliang;Zhou Baoping;Zhang Chunlei;Chai Chengzhi;Cao Zhengyu
(+)-椰果油烷(CNCP)是一种广泛存在于多种药用和食用植物中的新木脂素，具有广泛的生物活性。在此，我们证明了CNCP以浓度依赖的方式诱导人肾2(HK-2)细胞凋亡(IC_(50)= 19.3 μM)，并导致细胞内钙离子([Ca~(2+)]i)持续升高。细胞外钙离子浓度从2.3 mM降至0 mM时，对CNCP诱导的细胞外钙反应的抑制作用达69.1%。此外，用thapsigargin耗尽细胞内钙库可使CNCP诱导的细胞内钙库释放正常化，提示CNCP诱导的钙反应既包括细胞外钙内流，也包括细胞内钙库释放。TRPC3/6/7通道阻断剂SAR7334和TRPC1/4/5阻断剂Pico145均不能抑制CNCP诱导的细胞内钙离子浓度升高57.2%和细胞死亡53.4%，提示TRPC6通道在CNCP诱导的细胞内钙内流和细胞死亡中起重要作用。进一步的电生理记录表明，CNCP通过增加通道开放概率而直接激活TRPC6通道，EC50值为6.01 μM。这些结果表明，直接激活TRPC6通道参与了CNCP诱导的HK-2 细胞的死亡。我们的数据指出，如果将CNCP用作治疗药物，则存在潜在的肾毒性风险。
(+)-Conocarpan (CNCP), a neolignan frequently found in many medicinal and edible plants displays a broad spectrum of bioactivity. Here, we demonstrated that CNCP induced apoptotic cell death in human kidney-2 (HK-2) cells in a concentration-dependent manner (IC50= 19.3 μM) and led to the sustained elevation of intracellular Ca2+([Ca2+]i). Lower extracellular Ca2+concentrations from 2.3 mM to 0 mM significantly suppressed the CNCP-induced Ca2+response by 69.1%. Moreover, the depletion of intracellular Ca2+stores using thapsigargin normalized CNCP-induced Ca2+release from intracellular Ca2+stores, suggesting that the CNCP-induced Ca2+response involved both extracellular Ca2+influx and Ca2+release from intracellular Ca2+stores. SAR7334, a TRPC3/6/7 channel inhibitor, but neither Pyr3, a selective TRPC3 channel inhibitor, nor Pico145, a TRPC1/4/5 inhibitor, suppressed the CNCP-induced Ca2+response by 57.2% and decreased CNCP-induced cell death by 53.4%, suggesting a critical role for TRPC6 channels in CNCP-induced Ca2+influx and apoptotic cell death. Further electrophysiological recording demonstrated that CNCP directly activated TRPC6 channels by increasing channel open probability with an EC50value of 6.01 μM. Considered together, these data demonstrate that the direct activation of TRPC6 channels contributes to CNCP-induced apoptotic cell death in HK-2 cells. Our data point out the potential risk of renal toxicity from CNCP if used as a therapeutic agent.