Department of Pharmaceutical Sciences, Università del Piemonte Orientale, 28100 Novara, Italy.
Department of Pharmaceutical Sciences, Università di Pavia, 27100 Pavia, Italy.
Cells. 2020 Feb 21;9(2):496. doi: 10.3390/cells9020496.
(1) Background: Extracellular nicotinamide phosphoribosyltrasferase (eNAMPT) is released by various cell types with pro-tumoral and pro-inflammatory properties. In cancer, eNAMPT regulates tumor growth through the activation of intracellular pathways, suggesting that it acts through a putative receptor, although its nature is still elusive. It has been shown, using surface plasma resonance, that eNAMPT binds to the C-C chemokine receptor type 5 (CCR5), although the physiological meaning of this finding is unknown. The aim of the present work was to characterize the pharmacodynamics of eNAMPT on CCR5. (2) Methods: HeLa CCR5-overexpressing stable cell line and B16 melanoma cells were used. We focused on some phenotypic effects of CCR5 activation, such as calcium release and migration, to evaluate eNAMPT actions on this receptor. (3) Results: eNAMPT did not induce ERK activation or cytosolic Ca-rises alone. Furthermore, eNAMPT prevents CCR5 internalization mediated by Rantes. eNAMPT pretreatment inhibits CCR5-mediated PKC activation and Rantes-dependent calcium signaling. The effect of eNAMPT on CCR5 was specific, as the responses to ATP and carbachol were unaffected. This was strengthened by the observation that eNAMPT inhibited Rantes-induced Ca-rises and Rantes-induced migration in a melanoma cell line. (4) Conclusions: Our work shows that eNAMPT binds to CCR5 and acts as a natural antagonist of this receptor.
(1) 背景：细胞外烟酰胺磷酸核糖基转移酶（eNAMPT）是由多种具有促肿瘤和促炎作用的细胞类型释放的。在癌症中，eNAMPT 通过激活细胞内途径来调节肿瘤生长，这表明它通过一种假定的受体起作用，尽管其性质仍不清楚。已经表明，使用表面等离子体共振，eNAMPT 与 C-C 趋化因子受体 5（CCR5）结合，尽管这一发现的生理意义尚不清楚。本研究的目的是描述 eNAMPT 对 CCR5 的药效动力学。
(2) 方法：使用 HeLa CCR5 过表达稳定细胞系和 B16 黑色素瘤细胞。我们专注于 CCR5 激活的一些表型效应，如钙释放和迁移，以评估 eNAMPT 对该受体的作用。
(3) 结果：eNAMPT 本身不能诱导 ERK 激活或细胞内钙升高。此外，eNAMPT 可防止 Rantes 介导的 CCR5 内化。eNAMPT 预处理抑制 CCR5 介导的 PKC 激活和 Rantes 依赖性钙信号转导。eNAMPT 对 CCR5 的作用是特异性的，因为对 ATP 和卡巴胆碱的反应不受影响。这一观察结果得到了加强，即 eNAMPT 抑制了 Rantes 诱导的钙升高和黑色素瘤细胞系中 Rantes 诱导的迁移。
(4) 结论：我们的工作表明，eNAMPT 与 CCR5 结合并作为该受体的天然拮抗剂起作用。
