Plant Sterols Increased IL-6 and TNF-α Secretion from Macrophages, but to a Lesser Extent than Cholesterol

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Author(s)

    • Kurano Makoto
    • Department of Metabolic Diseases, Graduate School of Medicine, The University of Tokyo.
    • Iso-O Naoyuki
    • Department of Advanced Medical Science, The Institute of Medical Science, The University of Tokyo.
    • Hara Masumi
    • Fourth Department of Internal Medicine, Mizonokuchi Hospital, Teikyo University School of Medicine.
    • Noiri Eisei
    • Department of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo.
    • Koike Kazuhiko
    • Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo.
    • Kadowaki Takashi
    • Department of Metabolic Diseases, Graduate School of Medicine, The University of Tokyo.
    • Tsukamoto Kazuhisa
    • Department of Metabolic Diseases, Graduate School of Medicine, The University of Tokyo.

Abstract

Aim: Phytosterolemia is an inherited disorder characterized by hypercholesterolemia and premature atherosclerosis, together with increased inflammatory states in some cases. The underlying mechanisms of atherogenesis in phytosterolemia, however, have not been completely elucidated. In this study, we investigated whether phytosterols would affect inflammatory reactions in macrophages and macrophage cell lines.<BR>Methods:We incubated RAW264.7 cells (RAW) and mouse peritoneal macrophages (MPMs) with sitosterol (Sito), campesterol (Camp) or cholesterol (Chol) at low (8 µM, 16 µM) or high (160 µM) concentrations, and investigated their effects on LPS-induced secretion of IL-6 and TNF-α. We also analyzed their effects on endoplasmic reticulum (ER) stress in both cells, and on the cell proliferation of RAW.<BR>Results: At low sterol concentrations, only Chol resulted in a tendency toward the increased secretion of TNF-α from MPMs. At high concentrations, Chol induced a significant increase in TNF-α secretions from both cells; however, Sito resulted in a non-significant increase in TNF-α secretion. The effects on IL-6 secretions of Sito were also significantly less than those of Chol. Camp increased the secretions of both cytokines from MPMs; however, the extent of these increases was less pronounced than that of Chol. Augmentation of ER stress was greatest with Chol among the sterols, and the proliferation of RAW cells was inhibited only with Chol.<BR>Conclusion: The lesser degree of inflammatory reactions and toxicity in macrophages with phytosterols than with cholesterol suggests that plant sterols themselves might not be primarily responsible for atherogenesis in phytosterolemia.

Journal

  • Journal of Atherosclerosis and Thrombosis

    Journal of Atherosclerosis and Thrombosis 18(5), 373-383, 2011

    Japan Atherosclerosis Society

Codes

  • NII Article ID (NAID)
    130004845378
  • Text Lang
    ENG
  • ISSN
    1340-3478
  • Data Source
    J-STAGE 
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