A pivotal role of the human kidney in catabolism of HDL protein components apolipoprotein A-I and A-IV but not of A-II.
Renal handling of major HDL components was studied by analyzing urine from patients with Fanconi syndrome, a rare renal proximal tubular reabsorption failure, including dysfunction of the kidney HDL receptor, cubilin. A high urinary excretion of apolipoprotein A-I and A-IV corresponding to a major part of the metabolism of these proteins was measured. In contrast, no urinary excretion of apolipoprotein A-II which is more hydrophobic and tighter bound to HDL was found. Control urines displayed absence of the three apolipoproteins. Urinary excretion of phospholipids, triglycerides, cholesterol and cholesterol esters in patients was as low as in controls. In conclusion, these data indicate that the human kidney is a major site for filtered nascent apolipoprotein A-I and A-IV but not for HDL particles.
Graversen
Jonas Heilskov
JH
Department of Medical Biochemistry, University of Aarhus, 8000 Aarhus C, Denmark. jhg@biokemi.au.dk
Castro
Graciela
G
Kandoussi
Abdelmejid
A
Nielsen
Henning
H
Christensen
Erik Ilsø
EI
Norden
Anthony
A
Moestrup
Søren Kragh
SK
D016632:Apolipoprotein A-I / Q000378:metabolism*; D016633:Apolipoprotein A-II / Q000378:metabolism*; D001054:Apolipoproteins A / Q000378:metabolism*; D005198:Fanconi Syndrome / Q000378:metabolism / Q000503:physiopathology / Q000652:urine; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism / Q000502:physiology* / Q000503:physiopathology; D007687:Kidney Tubules, Proximal / Q000378:metabolism
D016632:Apolipoprotein A-I; D016633:Apolipoprotein A-II; D001054:Apolipoproteins A; C022205:apolipoprotein A-IV