The in situ expression of interleukin-8 in the normal human kidney and in different morphological forms of glomerulonephritis.
BACKGROUND
Interleukin-8 (IL-8) is considered a deleterious chemokine involved in renal injury in glomerulonephritis (GN). IL-8 may be released as a 77-amino acid (AA) peptide or 72-AA protein.


METHODS
We evaluated gene and protein expression of IL-8 in 53 renal biopsy specimens from patients with GN and 9 control kidneys. Nonradioactive in situ hybridization and reverse-transcriptase polymerase chain reaction (RT-PCR) were applied to detect IL-8 messenger RNA (mRNA). In immunohistochemistry, a double-staining technique with the use of antibodies against the 77-AA and 72-AA forms of IL-8, as well as glomerular cell antigens, was used.


RESULTS
By in situ hybridization, IL-8 mRNA was detected in normal glomerular, tubular, and some interstitial cells. The RT-PCR study showed that IL-8 mRNA expression in control kidneys significantly exceeds that in specimens with GN (0.89 +/- 0.82 versus 0.21 +/- 0.20; P < 0.003). In control kidneys, major sources of 77-AA IL-8 were podocytes and endothelial cells of interstitial vessels, whereas tubular epithelial cells expressed minute amounts of 72-AA IL-8. In GN specimens, podocyte expression of 72-AA IL-8 varied notably, with the greatest level found in minimal change disease and the lowest level found in acute endocapillary GN. Conversely, increased glomerular expression of the 72-AA form of IL-8 was a general feature of GN, with its level significantly exceeding that of the 77-AA form in acute endocapillary GN (P < 0.01).


CONCLUSIONS
Our results suggest that intrinsic glomerular cell production of IL-8, in particular the 77-AA form, may be relevant for preservation of the glomerular architecture.
Niemir
Zofia I
ZI
Department of Nephrology, University of Medical Sciences, Poznan, Poland. zniemir@usoms.poznan.pl
Stein
Henning
H
Ciechanowicz
Andrzej
A
Olejniczak
Pawel
P
Dworacki
Grzegorz
G
Ritz
Eberhard
E
Waldherr
Ruediger
R
Czekalski
Stanislaw
S
D019867:Anti-Glomerular Basement Membrane Disease / Q000235:genetics / Q000473:pathology; D001706:Biopsy; D005786:Gene Expression Regulation / Q000235:genetics; D005921:Glomerulonephritis / Q000235:genetics* / Q000473:pathology; D005922:Glomerulonephritis, IGA / Q000235:genetics / Q000473:pathology; D015432:Glomerulonephritis, Membranoproliferative / Q000235:genetics / Q000473:pathology; D015433:Glomerulonephritis, Membranous / Q000235:genetics / Q000473:pathology; D005923:Glomerulosclerosis, Focal Segmental / Q000235:genetics / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods*; D016209:Interleukin-8 / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D007678:Kidney Glomerulus / Q000737:chemistry / Q000378:metabolism / Q000473:pathology / Q000502:physiology; D008181:Lupus Nephritis / Q000235:genetics / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics
D016209:Interleukin-8; D012333:RNA, Messenger