Nephrology Dialysis Transplantation, Vol 13, Issue 4 886-892, Copyright © 1998 by Oxford University Press
M Ruiz-Ortega, C Bustos, J Plaza and
Background: One common feature of renal diseases is
the development of interstitial fibrosis, but the mechanism of the process
remains undefined. We hypothesized that platelet-activating factor (PAF) a
classical acute inflammatory mediator involved in the pathogenesis of renal
damage, acts on renal tubulointerstitial cells, contributing to the
development of fibrosis. For this reason we evaluated the effect of PAF on
matrix regulation and cell-growth-related events in tubulointerstitial
cells. Methods: In vitro studies were conducted with
two tubulointerstitial cell lines: renal tubuloepithelial cells (NRK 52E)
and interstitial fibroblasts (NRK 49F). The effect of PAF on extracellular
matrix gene expression was determined by Northern blot. Fibronectin
synthesis was quantified by metabolic labelling and immunoprecipitation.
Cell growth changes were evaluated by fluorescence-activated cell-sorting
analysis (cell cycle and size) and total protein content by
3[H]leucine incorporation.
Results: In renal tubuloepithelial cells and
interstitial fibroblasts, PAF increased fibronectin mRNA expression.
PAF-effect on the expression of collagen genes differed depending on the
cell type studied. In tubuloepithelial cells there was an increase in type
I and IV collagen mRNA levels, while only type I collagen was increased in
fibroblasts. The overexpression of matrix proteins induced by PAF was
completely blocked by preincubation of cells with the PAF receptor
antagonist, BN52021. The PAF-induced upregulation of fibronectin expression
was correlated with the increase in fibronectin synthesis. These effects
were not associated with an increase in hyperplasia (characterized by
changes in cell cycle) either in tubuloepithelial cells or in interstitial
fibroblasts. Moreover, PAF did not induce tubular hypertrophy (changes in
protein content and cell size). Conclusions: Our data
suggest that PAF could be a mediator involved in extracellular matrix
accumulation and, therefore, participate in the formation of renal
interstitial fibrosis. Key words: platelet-activating
factor; tubulointerstitial fibrosis; matrix production
ORIGINAL ARTICLES
Overexpression of extracellular matrix proteins in renal tubulointerstitial cells by platelet-activating factor stimulation
Renal Research Laboratory, Fundacion Jimenez Diaz, Avda. Reyes Catolicos, 2, E-28040 Madrid, Spain; Corresponding author
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
N. Lloberas, J. M. Cruzado, J. Torras, I. Herrero-Fresneda, M. Riera, M. Merlos, and J. M. Grinyo Protective effect of UR-12670 on chronic nephropathy induced by warm ischaemia in ageing uninephrectomized rats Nephrol. Dial. Transplant., April 1, 2001; 16(4): 735 - 741. [Abstract] [Full Text] [PDF] |
||||
