A Synthetic Biotinylated Peptide, BP21, Inhibits the Induction of mRNA Expression of Inflammatory Substances by Oxidized- and Lyso-Phosphatidylcholine

Preclinical Research Oxidized low‐density lipoprotein (ox‐LDL) is implicated in many inflammatory diseases, e.g., type 2 diabetes, obesity, atherosclerosis, and metabolic syndrome. We previously reported that a synthetic biotinylated peptide, BP21, inhibits the bioactivity of ox‐LDL via direct binding to ox‐LDL. Here, we investigated the effect of BP21 on the mRNA expression of proinflammatory mediators induced by two major components of ox‐LDL, oxidized‐ and lyso‐phosphatidylcholine (ox‐PC and LPC), in monocytes/macrophages (THP‐1 cells) and adipocytes (3T3‐L1 cells). In THP‐1 cells, BP21 markedly reduced the mRNA expression of interleukin (IL)‐6, adipocyte fatty acid‐binding protein (aP2), tumor necrosis factor‐α, and mitogen‐activated protein kinase phosphatase‐1, which are induced by one of the major bioactive components of ox‐PC, 1‐palmitoyl‐2‐(5′‐oxo‐valeroyl)‐sn‐glycero‐3‐phosphocholine (POVPC), and reduced the mRNA expression of IL‐6, the ox‐LDL‐specific scavenger receptor CD36, and aP2 induced by LPC. In adipocytes, the mRNA expression of IL‐1β as an adipokine and aP2 is highly induced by ox‐PC and LPC, and BP21 markedly reduced the mRNA expression of IL‐1β and aP2 induced by POVPC and LPC. Furthermore, BP21 specifically bound to LPC and POVPC in a dose‐dependent manner. These results suggest that BP21 may be useful lead for the potential treatment and prevention of inflammatory diseases caused by ox‐PC and LPC.