caa a22 4500 606236481 CHVBK 20210128101248.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s11010-014-2259-0 doi (NATIONALLICENCE)springer-10.1007/s11010-014-2259-0 Lipopolysaccharide augments the uptake of oxidized LDL by up-regulating lectin-like oxidized LDL receptor-1 in macrophages [Elektronische Daten] [Ekhtear Hossain, Akinobu Ota, Sivasundaram Karnan, Miyuki Takahashi, Shahnewaj Mannan, Hiroyuki Konishi, Yoshitaka Hosokawa] There is a growing body of evidence supporting an intimate association of immune activation with the pathogenesis of cardiovascular diseases, including atherosclerosis. Uptake of oxidized low-density lipoprotein (oxLDL) through scavenging receptors promotes the formation of mature lipid-laden macrophages, which subsequently leads to exacerbation of regional inflammation and atherosclerotic plaque formation. In this study, we first examined changes in the mRNA level of the lectin-like oxLDL receptor-1 (LOX-1) in the mouse macrophage cell line RAW264.7 and the human PMA-induced macrophage cell line THP-1 after LPS stimulation. LPS significantly up-regulated LOX-1 mRNA in RAW264.7 cells; LOX-1 cell-surface protein expression was also increased. Flow cytometry and fluorescence microscopy analyses showed that cellular uptake of fluorescence (Dil)-labeled oxLDL was significantly augmented with LPS stimulation. The augmented uptake of Dil-oxLDL was almost completely abrogated by treatment with an anti-LOX-1 antibody. Of note, knockdown of Erk1/2 resulted in a significant reduction of LPS-induced LOX-1 up-regulation. Treatment with U0126, a specific inhibitor of MEK, significantly suppressed LPS-induced expression of LOX-1 at both the mRNA and protein levels. Furthermore, LOX-1 promoter activity was significantly augmented by LPS stimulation; this augmentation was prevented by U0126 treatment. Similar results were also observed in human PMA-induced THP-1 macrophages. Taken together, our results indicate that LPS up-regulates LOX-1, at least in part through activation of the Erk1/2 signaling pathway, followed by augmented cellular oxLDL uptake, thus highlighting a critical role of TLR4-mediated aberrant LOX-1 signaling in the pathogenesis of atherosclerosis. Springer Science+Business Media New York, 2014 LPS nationallicence LOX-1 nationallicence Atherosclerosis nationallicence Erk1/2 nationallicence Molecular biology nationallicence ABCA1 : ATP-binding cassette, sub-family A, member 1 nationallicence AP-1 : Activator protein 1 nationallicence CAPE : Caffeic acid phenethylester nationallicence DAPI : 4′,6-Diamidine-2′-phenylindole dihydrochloride nationallicence DCFH-DA : 2,7-Dichlorofluorescin diacetate nationallicence Dil : 1,1′-Dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate nationallicence Erk1/2 : Extracellular signal-regulated protein kinases 1 and 2 nationallicence FACS : Fluorescence-activated cell sorting nationallicence GAPDH : Glyceraldehyde-3-phosphate dehydrogenase nationallicence JNK : C-Jun N-terminal kinases nationallicence LOX-1 : Lectin-like oxidized low-density lipoprotein receptor-1 nationallicence MAPK : Mitogen-activated protein kinase nationallicence MEK : MAPK/Erk kinase nationallicence NF-κB : Nuclear factor of kappa light polypeptide gene enhancer in B cells nationallicence oxLDL : Oxidized low-density lipoprotein nationallicence SR-A : Scavenger receptor A nationallicence Hossain Ekhtear Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut Ota Akinobu Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut Karnan Sivasundaram Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut Takahashi Miyuki Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut Mannan Shahnewaj Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut Konishi Hiroyuki Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut Hosokawa Yoshitaka Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut Molecular and Cellular Biochemistry Springer US; http://www.springer-ny.com 400/1-2(2015-02-01), 29-40 0300-8177 400:1-2<29 2015 400 11010 https://doi.org/10.1007/s11010-014-2259-0 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11010-014-2259-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hossain Ekhtear Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut NATIONALLICENCE 700 1- Ota Akinobu Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut NATIONALLICENCE 700 1- Karnan Sivasundaram Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut NATIONALLICENCE 700 1- Takahashi Miyuki Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut NATIONALLICENCE 700 1- Mannan Shahnewaj Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut NATIONALLICENCE 700 1- Konishi Hiroyuki Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut NATIONALLICENCE 700 1- Hosokawa Yoshitaka Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Springer US; http://www.springer-ny.com 400/1-2(2015-02-01), 29-40 0300-8177 400:1-2<29 2015 400 11010