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Molecular and Cellular Biochemistry

, Volume 400, Issue 1–2, pp 29–40 | Cite as

Lipopolysaccharide augments the uptake of oxidized LDL by up-regulating lectin-like oxidized LDL receptor-1 in macrophages

  • Ekhtear Hossain
  • Akinobu Ota
  • Sivasundaram Karnan
  • Miyuki Takahashi
  • Shahnewaj B. Mannan
  • Hiroyuki Konishi
  • Yoshitaka Hosokawa
Article

Abstract

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.

Keywords

LPS LOX-1 Atherosclerosis Erk1/2 Molecular biology 

Abbreviations

ABCA1

ATP-binding cassette, sub-family A, member 1

AP-1

Activator protein 1

CAPE

Caffeic acid phenethylester

DAPI

4′,6-Diamidine-2′-phenylindole dihydrochloride

DCFH-DA

2,7-Dichlorofluorescin diacetate

Dil

1,1′-Dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate

Erk1/2

Extracellular signal-regulated protein kinases 1 and 2

FACS

Fluorescence-activated cell sorting

GAPDH

Glyceraldehyde-3-phosphate dehydrogenase

JNK

C-Jun N-terminal kinases

LOX-1

Lectin-like oxidized low-density lipoprotein receptor-1

MAPK

Mitogen-activated protein kinase

MEK

MAPK/Erk kinase

NF-κB

Nuclear factor of kappa light polypeptide gene enhancer in B cells

oxLDL

Oxidized low-density lipoprotein

SR-A

Scavenger receptor A

Notes

Acknowledgments

This work was partly supported by a grant from the Strategic Research Foundation Grant-aided Project for Private Universities from the Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) [S1101027 to S. K., H. K., and Y. H.]; and the AIKEIKAI Foundation [to A. O.]. We would like to thank Dr. Takashi Yokochi and Dr. Hiroshi Miwa at Aichi Medical University (Aichi, Japan) for kindly providing the RAW264.7 mouse macrophage cell line and THP-1 human acute monocytic leukemia cell line, respectively.

Conflict of interest disclosure

We declare that we have no conflict of interest.

Supplementary material

11010_2014_2259_MOESM1_ESM.pdf (292 kb)
Supplementary material 1 (PDF 291 kb)

References

  1. 1.
    Taghavie-Moghadam PL, Butcher MJ, Galkina EV (2014) The dynamic lives of macrophage and dendritic cell subsets in atherosclerosis. Ann N Y Acad Sci 19:19–37CrossRefGoogle Scholar
  2. 2.
    Tabas I (2010) Macrophage death and defective inflammation resolution in atherosclerosis. Nat Rev Immunol 10:36–46PubMedCentralCrossRefPubMedGoogle Scholar
  3. 3.
    Libby P, Lichtman AH, Hansson GK (2013) Immune effector mechanisms implicated in atherosclerosis: from mice to humans. Immunity 38:1092–1104PubMedCentralCrossRefPubMedGoogle Scholar
  4. 4.
    Libby P, Ridker PM, Hansson GK (2011) Progress and challenges in translating the biology of atherosclerosis. Nature 473:317–325CrossRefPubMedGoogle Scholar
  5. 5.
    Goyal T, Mitr S, Khaidakov M, Wang X, Singla S, Ding Z, Liu S, Mehta JL (2012) Current concepts of the role of oxidized LDL receptors in atherosclerosis. Curr Atheroscler Rep 14:150–159CrossRefGoogle Scholar
  6. 6.
    Martín-Fuentes P, Civeira F, Recalde D, García-Otín AL, Jarauta E, Marzo I, Cenarro A (2007) Individual variation of scavenger receptor expression in human macrophages with oxidized low-density lipoprotein is associated with a differential inflammatory response. J Immunol 179:3242–3248CrossRefPubMedGoogle Scholar
  7. 7.
    Sawamura T, Kume N, Aoyama T, Moriwaki H, Hoshikawa H, Aiba Y, Tanaka T, Miwa S, Katsura Y, Kita T, Masaki T (1997) An endothelial receptor for oxidized low-density lipoprotein. Nature 386:73–77CrossRefPubMedGoogle Scholar
  8. 8.
    Mitra S, Goyal T, Mehta JL (2011) Oxidized LDL, LOX-1 and atherosclerosis. Cardiovasc Drugs Ther 5:419–429CrossRefGoogle Scholar
  9. 9.
    Kataoka H, Kume N, Miyamoto S, Minami M, Moriwaki H, Murase T, Sawamura T, Masaki T, Hashimoto T, Kita T (1999) Expression of lectin-like oxidized low-density lipoprotein receptor-1 in human atherosclerotic lesions. Circulation 99:3110–3117CrossRefPubMedGoogle Scholar
  10. 10.
    Inoue K, Arai Y, Kurihara H, Kita T, Sawamura T (2005) Overexpression of lectin-like oxidized low-density lipoprotein receptor-1 induces intramyocardial vasculopathy in apolipoprotein E-null mice. Circ Res 97:176–184CrossRefPubMedGoogle Scholar
  11. 11.
    Ding Z, Mizeracki AM, Hu C, Mehta JL (2013) LOX-1 deletion and macrophage trafficking in atherosclerosis. Biochem Biophys Res Commun 440:210–214CrossRefPubMedGoogle Scholar
  12. 12.
    Taront S, Dieudonné A, Blanchard S, Jeannin P, Lassalle P, Delneste Y, Gosset P (2009) Implication of scavenger receptors in the interactions between diesel exhaust particles and immature or mature dendritic cells. Part Fibre Toxicol 6:9PubMedCentralCrossRefPubMedGoogle Scholar
  13. 13.
    Funk JL, Feingold KR, Moser AH, Grunfeld C (1993) Lipopolysaccharide stimulation of RAW 264.7 macrophages induces lipid accumulation and foam cell formation. Atherosclerosis 98:67–82CrossRefPubMedGoogle Scholar
  14. 14.
    El Fiky A, Perreault R, McGinnis GJ, Rabin RL (2013) Attenuated expression of interferon-β and interferon-λ1 by human alternatively activated macrophages. Hum Immunol 74:1524–1530CrossRefPubMedGoogle Scholar
  15. 15.
    Komura T, Sakai Y, Honda M, Takamura T, Wada T, Kaneko S (2013) ER stress induced impaired TLR signaling and macrophage differentiation of human monocytes. Cell Immunol 282:44–52CrossRefPubMedGoogle Scholar
  16. 16.
    Takahashi M, Ota A, Karnan S, Hossain E, Konishi Y, Damdindorj L, Konishi H, Yokochi T, Nitta M, Hosokawa Y (2013) Arsenic trioxide prevents nitric oxide production in lipopolysaccharide-stimulated RAW264.7 by inhibiting a TRIF-dependent pathway. Cancer Sci 104:165–170CrossRefPubMedGoogle Scholar
  17. 17.
    Hossain E, Ota A, Takahashi M, Karnan S, Damdindorj L, Konishi Y, Konishi H, Hosokawa Y (2013) Arsenic upregulates the expression of angiotensin II Type I receptor in mouse aortic endothelial cells. Toxicol Lett 220:70–75CrossRefPubMedGoogle Scholar
  18. 18.
    Hossain E, Ota A, Karnan S, Damdindorj L, Takahashi M, Konishi Y, Konishi H, Hosokawa Y (2013) Arsenic augments the uptake of oxidized LDL by upregulating the expression of lectin-like oxidized LDL receptor in mouse aortic endothelial cells. Toxicol Appl Pharmacol 273:651–658CrossRefPubMedGoogle Scholar
  19. 19.
    Zernecke A, Weber C (2014) Chemokines in atherosclerosis: proceedings resumed. Arterioscler Thromb Vasc Biol 34:742–750CrossRefPubMedGoogle Scholar
  20. 20.
    Chen J, Liu Y, Liu H, Hermonat PL, Mehta JL (2006) Molecular dissection of angiotensin II-activated human LOX-1 promoter. Arterioscler Thromb Vasc Biol 26:1163–1168CrossRefPubMedGoogle Scholar
  21. 21.
    Ueno T, Fukuda N, Tsunemi A, Yao EH, Matsuda H, Tahira K, Matsumoto T, Matsumoto K, Matsumoto Y, Nagase H, Sugiyama H, Sawamura T (2009) A novel gene silencer, pyrrole-imidazole polyamide targeting human lectin-like oxidized low-density lipoprotein receptor-1 gene improves endothelial cell function. J Hypertens 27:508–516CrossRefPubMedGoogle Scholar
  22. 22.
    Chen M, Masaki T, Sawamura T (2002) LOX-1, the receptor for oxidized low-density lipoprotein identified from endothelial cells: implications in endothelial dysfunction and atherosclerosis. Pharmacol Ther 95:89–100CrossRefPubMedGoogle Scholar
  23. 23.
    Hu C, Dandapat A, Sun L, Chen J, Marwali MR, Romeo F, Sawamura T, Mehta JL (2008) LOX-1 deletion decreases collagen accumulation in atherosclerotic plaque in low-density lipoprotein receptor knockout mice fed a high-cholesterol diet. Cardiovasc Res 79:287–293CrossRefPubMedGoogle Scholar
  24. 24.
    Kume N, Murase T, Moriwaki, Aoyama T, Sawamura T, Masaki T, Kita T (1998) Inducible expression of lectin-like oxidized LDL receptor-1 in vascular endothelial cells. Circ Res 83:322–327CrossRefPubMedGoogle Scholar
  25. 25.
    Nagase M, Abe J, Takahashi K, Ando J, Hirose S, Fujita T (1998) Genomic organization and regulation of expression of the lectin-like oxidized low-density lipoprotein receptor (LOX-1) gene. J Biol Chem 273:33702–33707CrossRefPubMedGoogle Scholar
  26. 26.
    Li D, Mehta JL (2000) Upregulation of endothelial receptor for oxidized LDL (LOX-1) by oxidized LDL and implications in apoptosis of human coronary artery endothelial cells: evidence from use of antisense LOX-1 mRNA and chemical inhibitors. Arterioscler Thromb Vasc Biol 20:1116–1122CrossRefPubMedGoogle Scholar
  27. 27.
    Murase T, Kume N, Korenaga R, Ando J, Sawamura T, Masaki T, Kita T (1998) Fluid shear stress transcriptionally induces lectin-like oxidized LDL receptor-1 in vascular endothelial cells. Circ Res 83:328–333CrossRefPubMedGoogle Scholar
  28. 28.
    Schaeffer DF, Riazy M, Parhar KS, Chen JH, Duronio V, Sawamura T, Steinbrecher UP (2009) LOX-1 augments oxLDL uptake by lysoPC-stimulated murine macrophages but is not required for oxLDL clearance from plasma. J Lipid Res 50:1676–1684PubMedCentralCrossRefPubMedGoogle Scholar
  29. 29.
    Hermonat PL, Zhu H, Cao M, Mehta JL (2011) LOX-1 transcription. Cardiovasc Drugs Ther 25:393–400CrossRefPubMedGoogle Scholar
  30. 30.
    Zhao W, Ma G, Chen X (2014) Lipopolysaccharide induced LOX-1 expression via TLR4/MyD88/ROS activated p38MAPK-NF-κB pathway. Vascul Pharmacol S1537–1891(14):00128-1. doi: 10.1016/j.vph.2014.06.008 Google Scholar
  31. 31.
    Fitzgerald ML, Moore KJ, Freeman MW, Reed GL (2000) Lipopolysaccharide induces scavenger receptor A expression in mouse macrophages: a divergent response relative to human THP-1 monocyte/macrophages. J Immunol 164:2692–2700CrossRefPubMedGoogle Scholar
  32. 32.
    Yesner LM, Huh HY, Pearce SF, Silverstein RL (1996) Regulation of monocyte CD36 and thrombospondin-1 expression by soluble mediators. Arterioscler Thromb Vasc Biol 16:1019–1025CrossRefPubMedGoogle Scholar
  33. 33.
    Kataoka H, Kume N, Miyamoto S, Minami M, Moriwaki H, Murase T, Sawamura T, Masaki T, Hashimoto N, Kita T (1999) Expression of lectinlike oxidized low-density lipoprotein receptor-1 in human atherosclerotic lesions. Circulation 99:3110–3117CrossRefPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • Ekhtear Hossain
    • 1
  • Akinobu Ota
    • 1
    • 3
  • Sivasundaram Karnan
    • 1
  • Miyuki Takahashi
    • 1
    • 2
  • Shahnewaj B. Mannan
    • 1
  • Hiroyuki Konishi
    • 1
  • Yoshitaka Hosokawa
    • 1
  1. 1.Department of BiochemistryAichi Medical University School of MedicineNagakuteJapan
  2. 2.Division of Hematology, Department of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
  3. 3.Department of BiochemistryAichi Medical University School of MedicineNagakuteJapan

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