Hypercholesterolemia is a prerequisite for puromycin inducible damage in mouse kidney.
BACKGROUND
The mouse, as opposed to the rat, is relatively resistant to the experimental nephrosis induced by puromycin aminonucleoside. The reason for this species specificity is not known. Apolipoprotein E (apoE)-deficient mice were used to determine whether hypercholesterolemia plays a role in inducing proteinuria.


METHODS
Thirty-two mice were divided into normal and high cholesterol diet groups and then divided further into four subgroups: puromycin, puromycin+probucol, probucol and control. Urinary albumin of these mice was analyzed by nephelometry. The lipid peroxidation (LPO) end products malonyldialdehyde (MDA) and 4-hydroxynonenal (4-HNE) were detected by immunohistochemistry, and the expression level of the glomerular slit diaphragm protein, nephrin, was studied by immunohistochemistry and real time RT-PCR.


RESULTS
Overt proteinuria was induced by puromycin only in the apoE knockout mice ingesting the high cholesterol diet. The staining intensities of MDA and 4-HNE were stronger in the glomeruli of proteinuric mice compared to glomeruli of non-proteinuric mice. When serum cholesterol levels were reduced by probucol, proteinuria decreased and fewer LPO end products were seen immunohistochemically. Three and eight days after puromycin injection the level of nephrin mRNA in the kidneys of proteinuric mice decreased in comparison to the controls. Puromycin-treated mice kidneys demonstrated a clearly reduced reactivity to the nephrin antibodies.


CONCLUSIONS
Hypercholesterolemia, possibly via LPO, is a prerequisite for puromycin-inducible glomerular damage in the mouse. Furthermore, nephrin protein and mRNA levels appear to be candidate markers of glomerular damage in the mouse.
Cheng
Zhu-Zhu
ZZ
Department of Bacteriology and Immunology, University of Helsinki and University Central Hospital, Helsinki, Finland.
Pätäri
Anu
A
Aalto-Setälä
Katriina
K
Novikov
Dmitry
D
Schlöndorff
Detlef
D
Holthöfer
Harry
H
D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics*; D002791:Cholesterol, Dietary / Q000494:pharmacology; D006937:Hypercholesterolemia / Q000378:metabolism / Q000473:pathology*; D007150:Immunohistochemistry; D015227:Lipid Peroxidation; D008565:Membrane Proteins; D051379:Mice; D018345:Mice, Knockout; D009401:Nephrosis / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*; D011500:Protein Synthesis Inhibitors; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D011507:Proteinuria / Q000378:metabolism / Q000473:pathology; D011691:Puromycin; D012333:RNA, Messenger / Q000032:analysis
D001057:Apolipoproteins E; D002791:Cholesterol, Dietary; D008565:Membrane Proteins; D011500:Protein Synthesis Inhibitors; D011506:Proteins; D012333:RNA, Messenger; C113267:nephrin; D011691:Puromycin