7 research outputs found
Explanting Is an Ex Vivo Model of Renal Epithelial-Mesenchymal Transition
Recognised by their
de novo expression of alpha-smooth muscle actin
(SMA), recruitment of myofibroblasts is key to
the pathogenesis of fibrosis in chronic kidney
disease. Increasingly, we realise that
epithelial-mesenchymal transition (EMT) may be an
important source of these cells. In this study
we describe a novel model of renal EMT. Rat
kidney explants were finely diced on
gelatin-coated Petri dishes and cultured in
serum-supplemented media. Morphology and
immunocytochemistry were used to identify
mesenchymal (vimentin+, α-smooth muscle
actin (SMA)+, desmin+), epithelial
(cytokeratin+), and endothelial (RECA+) cells at
various time points. Cell outgrowths were all
epithelial in origin (cytokeratin+) at day 3. By
day 10, 50 ± 12%
(mean ± SE) of cytokeratin+
cells double-labelled for SMA, indicating EMT.
Lectin staining established a proximal tubule
origin. By day 17, cultures consisted only of
myofibroblasts (SMA+/cytokeratin−). Explanting
is a reproducible ex vivo model
of EMT. The ability to modify this change in
phenotype provides a useful tool to study the
regulation and mechanisms of renal
tubulointerstitial fibrosis
Lovastatin downregulates renal myofibroblast function in vitro
Interstitial fibrosis is recognised as the best histological predictor of progressive renal disease. Myofibroblasts contribute to this process through several functions including hyperproliferation, collagen and collagenase synthesis and reorganisation of extracellular matrix. Recent limited in vitro studies suggest that 3-hydroxy-3-methylglutaryl-coenzyme A (HIVIG CoA) reductase inhibitors may reduce renal injury not only through their lipid-lowering effects but also by antagonising myofibroblast function. This study therefore examined the effects of lovastatin on the above interstitial myofibroblast behaviours in vitro. Primary cultures of rat renal cortical myofibroblasts were grown by explantation and characterised by immunohistochemistry. Dose response effects of lovastatin (0, 15,30 muM) in DMEM and 10% FCS were examined on myofibroblast kinetics, total collagen synthesis, collagen I lattice contraction and actin filament rearrangement. Lovastatin decreased myofibroblast proliferation and growth. Likewise, collagen I lattice contraction and actin filament rearrangement were partially inhibited when lovastatin was added at 30 M In addition, lovastatin decreased both collagen and collagenase synthesis. Our results suggest that myofibroblast function may be downregulated by lovastatin in vitro. Although a decrease in myofibroblast activity may offer potential benefit in the prevention of progressive scarring, further studies will be necessary to determine the relative importance of these functions. Copyright (C) 2002 S. Karger AG, Basel