TY - JOUR
T1 - Effects of cytokines on synthesis and function of the hepatic asialoglycoprotein receptor
AU - Treichel, Ulrich
AU - Paietta, Elisabeth
AU - Poralla, Thomas
AU - Meyer zum Büschenfelde, Karl‐Hermann ‐H
AU - Stockert, Richard J.
PY - 1994/3
Y1 - 1994/3
N2 - In this study we have investigated whether cytokines, critical mediators of the immune response, might have a direct effect on the expression and/or function of the human hepatic asialoglycoprotein receptor (ASGPR). Binding and uptake of asialoglycoproteins by the human hepatoma cell line, HepG2, and by freshly isolated rat hepatocytes were inhibited by 50% after 3–6 hours and completely abolished following a 24 hour exposure to tumor necrosis factor (TNF) α, interferon (INF) α or γ, or interleukin‐2 (IL‐2). The loss of ASGPR binding activity mediated by IL‐2 was reversible up to 4 hours of exposure and accompanied by the selective phosphorylatior, of the cell‐surface receptor. Steady‐state levels of total cellular ASGPR protein remained unchanged over the first 6 hours of IL‐2 incubation but declined in a dose dependent manner thereafter. This down regulation of ASGPR expression was due to reduced synthesis as a result of reduced receptor transcript levels. No loss was detected, however, of cell surface‐associated receptor protein even after 24 hours of IL‐2 incubation, suggesting that cytokine induced phosphorvlation constitutes a mechanism to regulate receptor activity. © 1994 Wiley‐Liss, Inc.
AB - In this study we have investigated whether cytokines, critical mediators of the immune response, might have a direct effect on the expression and/or function of the human hepatic asialoglycoprotein receptor (ASGPR). Binding and uptake of asialoglycoproteins by the human hepatoma cell line, HepG2, and by freshly isolated rat hepatocytes were inhibited by 50% after 3–6 hours and completely abolished following a 24 hour exposure to tumor necrosis factor (TNF) α, interferon (INF) α or γ, or interleukin‐2 (IL‐2). The loss of ASGPR binding activity mediated by IL‐2 was reversible up to 4 hours of exposure and accompanied by the selective phosphorylatior, of the cell‐surface receptor. Steady‐state levels of total cellular ASGPR protein remained unchanged over the first 6 hours of IL‐2 incubation but declined in a dose dependent manner thereafter. This down regulation of ASGPR expression was due to reduced synthesis as a result of reduced receptor transcript levels. No loss was detected, however, of cell surface‐associated receptor protein even after 24 hours of IL‐2 incubation, suggesting that cytokine induced phosphorvlation constitutes a mechanism to regulate receptor activity. © 1994 Wiley‐Liss, Inc.
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U2 - 10.1002/jcp.1041580319
DO - 10.1002/jcp.1041580319
M3 - Article
C2 - 8126076
AN - SCOPUS:0028330680
SN - 0021-9541
VL - 158
SP - 527
EP - 534
JO - Journal of Cellular Physiology
JF - Journal of Cellular Physiology
IS - 3
ER -