Bissinger Rosi, Malik Abaid, Warsi Jamshed, Jilani Kashif, Lang Florian
Department of Physiology, Eberhard-Karls-University of Tuebingen, Gmelinstr. 5, 72076 Tuebingen, Germany.
Toxins (Basel). 2014 Oct 14;6(10):2975-88. doi: 10.3390/toxins6102975.
Piperlongumine, a component of Piper longum fruit, is considered as a treatment for malignancy. It is effective by inducing apoptosis. Mechanisms involved in the apoptotic action of piperlongumine include oxidative stress and activation of p38 kinase. In analogy to apoptosis of nucleated cells, erythrocytes may undergo eryptosis, the suicidal death of erythrocytes characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine-exposure at the erythrocyte surface. Signaling involved in eryptosis include increase of cytosolic Ca²⁺-activity ([Ca²⁺]i), formation of ceramide, oxidative stress and activation of p38 kinase.
Cell volume was estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, [Ca²⁺]i from Fluo3 fluorescence, reactive oxygen species from 2',7'-dichlorodihydrofluorescein-diacetate fluorescence, and ceramide abundance from binding of fluorescent antibodies in flow cytometry.
A 48 h exposure to piperlongumine (30 µM) was followed by significant decrease of forward scatter and increase of annexin-V-binding. Piperlongumine did not significantly modify [Ca²⁺]i and the effect was not dependent on presence of extracellular Ca²⁺. Piperlongumine significantly increased ROS formation and ceramide abundance.
Piperlongumine triggers cell membrane scrambling, an effect independent from entry of extracellular Ca²⁺ but at least partially due to ROS and ceramide formation.
胡椒碱是长胡椒果实的一种成分，被认为可用于治疗恶性肿瘤。它通过诱导细胞凋亡发挥作用。胡椒碱凋亡作用的机制包括氧化应激和p38激酶的激活。与有核细胞的凋亡类似，红细胞可能会发生红细胞凋亡，即红细胞的自杀性死亡，其特征是细胞收缩和细胞膜磷脂酰丝氨酸外翻。红细胞凋亡涉及的信号包括胞质Ca²⁺活性（[Ca²⁺]i）增加、神经酰胺形成、氧化应激和p38激酶激活。
通过流式细胞术中前向散射估计细胞体积，通过膜联蛋白V结合估计磷脂酰丝氨酸外翻，通过Fluo3荧光估计[Ca²⁺]i，通过2',7'-二氯二氢荧光素二乙酸酯荧光估计活性氧，通过荧光抗体结合估计神经酰胺丰度。
暴露于胡椒碱（30 μM）48小时后，前向散射显著降低，膜联蛋白V结合增加。胡椒碱对[Ca²⁺]i无显著影响，且该效应不依赖于细胞外Ca²⁺的存在。胡椒碱显著增加活性氧生成和神经酰胺丰度。
胡椒碱引发细胞膜磷脂酰丝氨酸外翻，该效应独立于细胞外Ca²⁺的进入，但至少部分归因于活性氧和神经酰胺的形成。
