Cheng He-Hsiung, Chou Chiang-Ting, Liang Wei-Zhe, Kuo Chun-Chi, Shieh Pochuen, Wang Jue-Long, Jan Chung-Ren
Department of Medicine, Chang Bing Show Chwan Memorial Hospital, Changhua County 50544, Taiwan, Republic of China.
Department of Nursing, Division of Basic Medical Sciences, Chang Gung University of Science and Technology, Chia-Yi 61363, Taiwan, Republic of China.
Chin J Physiol. 2017 Apr 30;60(2):114-123. doi: 10.4077/CJP.2017.BAF459.
Protriptyline has been used as an antidepressant. Clinically it has been prescribed in the auxiliary treatment of cancer patients. However, its effect on Ca²⁺ signaling and related physiology is unknown in renal cells. This study examined the effect of protriptyline on cytosolic free Ca²⁺ concentrations ([Ca²⁺]i) and viability in Madin-Darby canine kidney (MDCK) tubular cells. Protriptyline induced [Ca²⁺]i rises concentration-dependently. The response was reduced by 20% by removing extracellular Ca²⁺. Protriptyline-induced Ca²⁺ entry was not altered by protein kinase C (PKC) activity but was inhibited by 20% by three modulators of store-operated Ca²⁺ channels: nifedipine, econazole and SKF96365. In Ca²⁺-free medium, treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor 2,5- di-tert-butylhydroquinone (BHQ) or thapsigargin partially inhibited protriptyline-evoked [Ca²⁺]i rises. Conversely, treatment with protriptyline inhibited partially BHQ or thapsigargin-evoked [Ca²⁺]i rises. Inhibition of phospholipase C (PLC) with U73122 did not change protriptyline-induced [Ca²⁺]i rises. Protriptyline at 5-200 μM decreased cell viability, which was not reversed by pretreatment with the Ca²⁺ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N’,N’-tetraacetic acid-acetoxymethyl ester (BAPTA/ AM). Together, in MDCK cells, protriptyline induced [Ca²⁺]i rises by evoking PLC-independent Ca²⁺ release from the endoplasmic reticulum and other unknown stores, and Ca²⁺ entry via PKCinsensitive store-operated Ca²⁺ entry. Protriptyline also caused Ca²⁺-independent cell death.
普罗替林曾被用作抗抑郁药。临床上它已被用于癌症患者的辅助治疗。然而，其对肾细胞中Ca²⁺信号传导及相关生理学的影响尚不清楚。本研究检测了普罗替林对犬肾（MDCK）肾小管细胞胞质游离Ca²⁺浓度（[Ca²⁺]i）和细胞活力的影响。普罗替林浓度依赖性地诱导[Ca²⁺]i升高。去除细胞外Ca²⁺后，反应降低了20%。普罗替林诱导的Ca²⁺内流不受蛋白激酶C（PKC）活性的影响，但被三种储存式Ca²⁺通道调节剂：硝苯地平、益康唑和SKF96365抑制了20%。在无Ca²⁺培养基中，用内质网Ca²⁺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普罗替林诱发的[Ca²⁺]i升高。相反，用普罗替林处理可部分抑制BHQ或毒胡萝卜素诱发的[Ca²⁺]i升高。用U73122抑制磷脂酶C（PLC）不会改变普罗替林诱导的[Ca²⁺]i升高。5-200μM的普罗替林降低了细胞活力，用Ca²⁺螯合剂1,2-双（2-氨基苯氧基）乙烷-N,N,N',N'-四乙酸乙酰甲酯（BAPTA/AM）预处理不能逆转这种情况。总之，在MDCK细胞中，普罗替林通过引发不依赖PLC的内质网和其他未知储存库的Ca²⁺释放以及通过PKC不敏感的储存式Ca²⁺内流来诱导[Ca²⁺]i升高。普罗替林还导致不依赖Ca²⁺的细胞死亡。
