Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland.
Jagiellonian Centre for Experimental Therapeutics, Jagiellonian University, Bobrzynskiego 14, 30-348, Kraków, Poland.
Sci Rep. 2024 Sep 5;14(1):20684. doi: 10.1038/s41598-024-71600-2.
Heme released from damaged and senescent red blood cells (RBCs) may contribute to oxidant-mediated cell injury. One of the recently investigated physiological processes, essential in preventing the inflammatory impact of labile heme, is its uptake from the bloodstream by endothelial cells (ECs). In this study, we investigated heme uptake by ECs starting from the model studies on the in vitro cellular level, through the endothelium layer on the ex vivo murine aortic tissues. As the cellular model, Human Aortic Endothelial Cells (HAECs) were chosen, and the concentration of labile heme was adjusted so to avoid the excessive toxic effect of the labile heme. We utilized label-free Raman imaging with two different excitation wavelengths to capture the uptake process in situ and characterize the oxidation state of the iron ion in the intercalated heme. The phenomenon of heme uptake was demonstrated in both, the healthy control C57Bl/6J and FVB animals, as well as in mice with developed atherosclerosis (ApoE/LDLR mice). In the presented work, we presented for the first time Raman-based evidence on the heme uptake process by endothelial cells in both, in vitro and ex vivo systems.
从受损和衰老的红细胞 (RBC) 中释放的血红素可能导致氧化剂介导的细胞损伤。最近研究的一个生理过程是，从血液中摄取不稳定血红素对于防止其炎症影响至关重要，内皮细胞 (EC) 就是通过这个过程摄取血红素的。在这项研究中，我们从体外细胞水平的模型研究开始，通过对离体鼠主动脉组织的内皮细胞层，研究了 EC 对血红素的摄取。作为细胞模型，我们选择了人主动脉内皮细胞 (HAEC)，并调整了不稳定血红素的浓度，以避免不稳定血红素的过度毒性作用。我们利用两种不同激发波长的无标记拉曼成像来原位捕获摄取过程，并对嵌入血红素中的铁离子的氧化态进行特征化。在健康对照 C57Bl/6J 和 FVB 动物以及动脉粥样硬化发展的小鼠 (ApoE/LDLR 小鼠) 中，均观察到血红素摄取现象。在本工作中，我们首次在体外和离体系统中，基于拉曼的证据证明了内皮细胞摄取血红素的过程。
