18F-fluorodeoxyglucose positron emission tomography\u2013computed tomography for assessing organ distribution of stressed red blood cells in mice

Wen-yu Yin,Yong-xiang Tang,Ning Li,Fang Peng,Zhi-min Zhang,Wei Xu,Jiao Yuan,Cheng Mei

doi:10.1038/s41598-021-82100-y

Wen-yu Yin, Yong-xiang Tang + Show 6 more

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https://doi.org/10.1038/s41598-021-82100-y

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Abstract

Red blood cells (RBCs) stressed by high temperature are similar to senescent or damaged RBCs in pathological conditions. RBCs can be efficiently labelled with 18F-fluorodeoxyglucose (FDG). The aim of this study was to assess stressed RBCs erythrophagocytosis and organ distribution in vivo with the application of 18F-FDG PET/CT. RBCs were induced under high temperature (48 °C) to prepare stressed RBCs. Fluorescence-activated cell sorting (FACS) was used to analyse reactive oxygen species (ROS) generation, intracellular Ca2+ concentration and membrane phosphatidylserine (PS) externalization of RBCs. 18F-FDG was used to label RBCs and assess the erythrophagocytosis. Finally, 18F-FDG PET/CT was applied to reveal and measure the organ distribution of stressed RBCs in mice. Compared with untreated RBCs, stressed RBCs decreased in cell volume and increased in ROS level, intracellular Ca2+ concentration, and PS exposure. RBCs could be labelled by 18F-FDG. Stressed RBCs tended to be phagocytosed by macrophages via assessment of FACS and radioactivity. 18F-FDG PET/CT imaging showed that stressed RBCs were mainly trapped in spleen, while untreated RBCs remained in circulation system. Thus, stressed RBCs can be effectively labelled by 18F-FDG and tend to be trapped in spleen of mice as assessed by PET/CT.

Highlights

Red blood cells (RBCs) stressed by high temperature are similar to senescent or damaged RBCs in pathological conditions
Forward scatter can reflect the relative volume of R BCs16, the forward scatter width (FSC-W) of untreated RBCs was higher than FSC-W of stressed RBCs, indicated that cell volume was smaller in stressed RBCs than in untreated RBCs (Fig. 1A,B)
reactive oxygen species (ROS) level and intracellular C a2+ concentration was described as mean fluorescence intensity (MFI), PS externalization was expressed as Annexin-positive percentage

Summary

Introduction

Red blood cells (RBCs) stressed by high temperature are similar to senescent or damaged RBCs in pathological conditions. The aim of this study was to assess stressed RBCs erythrophagocytosis and organ distribution in vivo with the application of 18F-FDG PET/CT. RBCs were induced under high temperature (48 °C) to prepare stressed RBCs. Fluorescence-activated cell sorting (FACS) was used to analyse reactive oxygen species (ROS) generation, intracellular Ca2+ concentration and membrane phosphatidylserine (PS) externalization of RBCs. 18F-FDG was used to label RBCs and assess the erythrophagocytosis. Some studies demonstrated that storage-damaged and senescent RBCs are mainly cleared by splenic red pulp macrophages[10,11], while other researchers consider hepatic macrophages as the vital cells in the clearance of aged and stressed R BCs12,13. 18F-FDG was used to label RBCs to detect erythrophagocytosis and PET/CT was performed to assess organ distribution of stressed RBCs in mice We used high temperature-induced stressed RBCs to simulate RBCs in pathologic conditions. 18F-FDG was used to label RBCs to detect erythrophagocytosis and PET/CT was performed to assess organ distribution of stressed RBCs in mice

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