Cheng He-Hsiung, Chou Chiang-Ting, Liang Wei-Zhe, Kuo Chun-Chi, Shieh Pochuan, Wang Jue-Long, Jan Chung-Ren
Department of Medicine, Chang Bing Show Chwan Memorial Hospital, Changhua County 50544, Taiwan.
Department of Nursing, Division of Basic Medical Sciences, Chang Gung University of Science and Technology, Chia-Yi 61363, Taiwan; Chronic Diseases and Health Promotion Research Center, Chang Gung University of Science and Technology, Chia-Yi 61363, Taiwan.
Environ Toxicol Pharmacol. 2017 Jun;52:83-89. doi: 10.1016/j.etap.2017.03.015. Epub 2017 Mar 24.
Puerarin is a natural compound and has been used as herb medication in a number of countries, especially in Asia. The effect of puerarin on Ca signaling is unknown in renal cells. This study examined whether puerarin affected Ca physiology in MDCK renal tubular cells. Cytosolic free Ca levels ([Ca]) were measured using the fluorescent dye fura-2. Cell viability was examined by using WST-1 assay. Puerarin induced [Ca] rises and the response was reduced by removing extracellular Ca. Puerarin-induced Ca entry was not altered by protein kinase C (PKC) activity, but was inhibited by nifedipine. In Ca-free medium, treatment with the endoplasmic reticulum Ca pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) or thapsigargin partly inhibited puerarin-evoked [Ca] rises. Inhibition of phospholipase C (PLC) with U73122 did not change puerarin-induced [Ca] rises. Puerarin at 25-50μM caused cytotoxicity, which was not reversed by pretreatment with the Ca chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). Collectively, in MDCK cells, puerarin induced [Ca] rises by evoking PLC-independent Ca release from the endoplasmic reticulum and other unknown stores, and Ca entry via nifedipine-sensitive, PKC-insensitive Ca entry pathways. Puerarin also caused Ca-independent cell death.
葛根素是一种天然化合物，在许多国家，尤其是亚洲国家，已被用作草药药物。葛根素对肾细胞钙信号的影响尚不清楚。本研究检测了葛根素是否影响MDCK肾小管细胞的钙生理。使用荧光染料fura-2测量胞质游离钙水平（[Ca]）。通过WST-1检测法检测细胞活力。葛根素诱导[Ca]升高，去除细胞外钙后反应减弱。葛根素诱导的钙内流不受蛋白激酶C（PKC）活性的影响，但被硝苯地平抑制。在无钙培养基中，用内质网钙泵抑制剂2,5-二叔丁基对苯二酚（BHQ）或毒胡萝卜素处理可部分抑制葛根素诱发的[Ca]升高。用U73122抑制磷脂酶C（PLC）不会改变葛根素诱导的[Ca]升高。25-50μM的葛根素会引起细胞毒性，用钙螯合剂1,2-双（2-氨基苯氧基）乙烷-N,N,N',N'-四乙酸-乙酰氧甲酯（BAPTA/AM）预处理不能逆转这种毒性。总体而言，在MDCK细胞中，葛根素通过引发内质网和其他未知储存库中不依赖PLC的钙释放以及通过硝苯地平敏感、PKC不敏感的钙内流途径诱导[Ca]升高。葛根素还会导致不依赖钙的细胞死亡。
