Particulate yeast β-glucan is internalized by RAW 264.7 macrophages and reduces the activity of the tumor-associated protease legumain. Issue 1 (July 2015)

• Record Type: Journal Article
• Authors: Berven, Lise; Skjeldal, Frode Miltzow; Prydz, Kristian; Zubaidi, Layla Mohammad Khader; Ballance, Simon; Thidemann Johansen, Harald; Samuelsen, Anne Berit C.
• Is Part Of: Bioactive carbohydrates and dietary fibre. Volume 6:Issue 1(2015)
• Page Start: 15
• Page End: 23
• Publication Date: 2015-07
• Subjects: Functional foods -- Periodicals; Fiber in human nutrition -- Periodicals; Carbohydrates -- Periodicals; Glycoproteins -- Periodicals; Functional Food -- Periodicals; Dietary Fiber -- Periodicals; Carbohydrates -- Periodicals; Carbohydrates; Fiber in human nutrition; Functional foods; Glycoproteins; Periodicals; 613.28
• DOI: 10.1016/j.bcdf.2015.06.003
• Languages: English
• ISSNs: 2212-6198

Abstract

<abstract abstract-type="author" id="ab0010"> <title id="sect0005">Abstract</title> <sec> <p id="sp0040">Yeast-derived β-glucans (Y-BG) are potential immune-modulating compounds able to activate macrophages. We investigated whether Y-BG affects the activity of a proteolytic enzyme, legumain, which is expressed in macrophages and involved in inflammatory conditions as well as in cancer development.</p> <p id="sp0045">RAW 264.7 macrophages were stimulated with either particulate (BG-P), water soluble (BG-S) or partly water soluble (BG-PS) Y-BG for 48 h, and cellular legumain activity was determined using a fluorogenic peptide substrate. BG-P inhibited legumain activity in a dose-dependent manner, while BG-S and BG-PS did not. Immunoblotting indicated that the observed inhibition of legumain activity was caused by reduced prolegumain synthesis within the cells, rather than inhibition of legumain proform activation. Blocking of the C-type lectin dectin-1 receptor with antibodies abolished the effect, revealing that this receptor was involved, and it was further demonstrated by confocal microscopy that fluorescently labeled BG-P was internalized into macrophages. RAW 264.7 macrophages stimulated with Y-BG for 6 h were shown to secrete TNF-α, and BG-P was more potent than BG-PS and BG-S in this respect. Y-BG is shown to inhibit legumain activity after internalization into macrophages, providing new insight into the mode of action of β-glucans.</p> </sec> </abstract>