Abstract: Objective To investigate whether ApoE^-/- mouse atherosclerotic plaque tissue and RAW 264.7 simultaneously express sodium hydrogen exchanger 1 (NHE1) and neurite guidance factor-1 (netrin-1), and their co-localization and interaction. Methods The atherosclerotic plaque model of mice was established, and the formation of atherosclerotic plaque was detected by HE staining; the expression and co-localization of NHE1 and netrin-1 in atherosclerotic plaque were detected by immunofluorescence and confocal microscopy; Oxidized low density lipoprotein (Ox-LDL) was used to interfere with RAW264.7 cells in mice, then Western blot assay was used to detect the expression of NHE 1 and netrin-1 proteins in samples with different concentrations and time intervention. Small interfering RNA (siRNA) targeting NHE1 gene was designed and transfected into RAW264.7 cells by liposome. The inhibition efficiency of small interfering RNA (siRNA) targeting NHE1 gene was detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and Western blot. Results The expression of NHE1 was up-regulated in atherosclerotic plaque of mice, and partly co-localized with netrin-1. Ox-LDL up-regulated the expression of NHE1 and netrin-1 in RAW264.7 cells in a time-concentration dependent manner (P＜0.05); the constructed NHE1 siRNA effectively inhibited the expression of NHE1 in RAW264.7 cells (P＜0.05); effective knockdown of NHE1 expression in RAW264.7 cells down-regulated the expression of increased NHE1 and netrin-1 proteins as a results of intervention by Ox-LDL(P＜0.05). Conclusions The expression of NHE1 and netrin-1 in atherosclerotic plaque and Ox-LDL-treated mouse macrophage line (RAW264.7) is up-regulated and co-localized. The expression of netrin-1 is affected by the expression of NHE1.

Key words: atherosclerosis, sodium hydrogen exchangers 1, netrin-1