Expression of very low density lipoprotein receptor mRNA in circulating human monocytes: its up-regulation by hypoxia

Although very low density lipoprotein (VLDL) receptor expression by macroph ages has been shown in the vascular wall, it is not dear whether or not cir culating monocytes express the VLDL receptor. We investigated the expressio n of VLDL receptor mRNA in human peripheral blood monocytes and monocyte-de rived macrophages by reverse transcriptase polymerase chain reaction (RT-PC R) and nucleotide sequencing after subcloning of PCR product. VLDL receptor mRNA was detected both in peripheral blood monocytes and monocyte-derived macrophages. Expression of VLDL receptor mRNA was upregulated by hypoxia in monocytes, whereas treatment with oxidized LDL. interleukin-1 beta or mono cyte chemoattractant protein-1 did not affect the levels of VLDL receptor m RNA in monocytes and macrophages. The present study shows a novel response of VLDL receptor mRNA to hypoxia, suggesting a role for VLDL receptor in th e metabolism of lipoproteins in the vascular wall and the development of at herosclerosis. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.