TY - JOUR
T1 - Endocytic adaptors Arh and Dab2 control homeostasis of circulatory cholesterol
AU - Tao, Wensi
AU - Moore, Robert
AU - Meng, Yue
AU - Smith, Elizabeth R
AU - Xu, Xiang Xi
N1 - Funding Information:
The work was supported by Office of Extramural Research, National Institutes of Health Grants R01 CA095071, R01 CA79716, and R01 CA75389, and by a pilot fund award from the Scientific Award Committee of the University of Miami Miller School of Medicine. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
PY - 2016/5
Y1 - 2016/5
N2 - High serum cholesterol (hypercholesterolemia) strongly associates with cardiovascular diseases as the atherogenic LDLs promote atheroma development in arteries (atherosclerosis). LDL clearance from the circulation by LDL receptor (LDLR)-mediated endocytosis by hepatic and peripheral tissues and subsequent feedback regulation of endogenous synthesis of cholesterol is a key determinant of serum LDL level. Human mutation analysis revealed that autosomal recessive hypercholesterolemia (ARH), an LDLR endocytic adaptor, perturbs LDLR function and thus impacts serum cholesterol levels. In our genetic analysis of mutant mice, we found that deletion of another LDLR endocytic adaptor, Disabled-2 (Dab2), only slightly affected serum cholesterol levels. However, elimination of both arh and dab2 genes in mice resulted in profound hypercholesterolemia similar to that resulting from ldlr homozygous deletion. In the liver, Dab2 is expressed in sinusoid endothelial cells but not in hepatocytes. When deleting both Dab2 and Arh, HMGCoA reductase level increased to the level similar to that of ldlr knockout. Thus, in the absence of Arh, Dab2 in liver endothelial cells regulates cholesterol synthesis in hepatocytes. We conclude that the combination of Arh and Dab2 is responsible for the majority of adaptor function in LDLR endocytosis and LDLR-mediated cholesterol homeostasis.- Wensi, T., R. Moore, Y. Meng, E. R. Smith, and X-X. Xu. Endocytic adaptors Arh and Dab2 control homeostasis of circulatory cholesterol. J. Lipid Res. 2016. 57: 809-817. 2016 by the American Society for Biochemistry and Molecular Biology, Inc.
AB - High serum cholesterol (hypercholesterolemia) strongly associates with cardiovascular diseases as the atherogenic LDLs promote atheroma development in arteries (atherosclerosis). LDL clearance from the circulation by LDL receptor (LDLR)-mediated endocytosis by hepatic and peripheral tissues and subsequent feedback regulation of endogenous synthesis of cholesterol is a key determinant of serum LDL level. Human mutation analysis revealed that autosomal recessive hypercholesterolemia (ARH), an LDLR endocytic adaptor, perturbs LDLR function and thus impacts serum cholesterol levels. In our genetic analysis of mutant mice, we found that deletion of another LDLR endocytic adaptor, Disabled-2 (Dab2), only slightly affected serum cholesterol levels. However, elimination of both arh and dab2 genes in mice resulted in profound hypercholesterolemia similar to that resulting from ldlr homozygous deletion. In the liver, Dab2 is expressed in sinusoid endothelial cells but not in hepatocytes. When deleting both Dab2 and Arh, HMGCoA reductase level increased to the level similar to that of ldlr knockout. Thus, in the absence of Arh, Dab2 in liver endothelial cells regulates cholesterol synthesis in hepatocytes. We conclude that the combination of Arh and Dab2 is responsible for the majority of adaptor function in LDLR endocytosis and LDLR-mediated cholesterol homeostasis.- Wensi, T., R. Moore, Y. Meng, E. R. Smith, and X-X. Xu. Endocytic adaptors Arh and Dab2 control homeostasis of circulatory cholesterol. J. Lipid Res. 2016. 57: 809-817. 2016 by the American Society for Biochemistry and Molecular Biology, Inc.
KW - Autosomal recessive hypercholesterolemia
KW - Disabled-2
KW - Endocytic trafficking
KW - Low density liproprotein
KW - Low density liproprotein receptor
KW - Serum cholesterol
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U2 - 10.1194/jlr.M063065
DO - 10.1194/jlr.M063065
M3 - Article
C2 - 27005486
AN - SCOPUS:84971343310
VL - 57
SP - 809
EP - 817
JO - Journal of Lipid Research
JF - Journal of Lipid Research
SN - 0022-2275
IS - 5
ER -