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Updated: Jul 10, 2026
Rat Mesentery Angiogenesis Assay
Published on: June 18, 2011
Complement (C5b-9) induces DNA synthesis in rat mesangial cells in vitro
W G Couser1, J W Pippin, S J Shankland
1Division of Nephrology, Department of Medicine, University of Washington, Seattle, Washington 98195, USA.
Background:
The membrane attack complex C5b-9 causes injury in many forms of immune-mediated glomerular diseases characterized by mesangial cell (MC) proliferation and inhibiting C5b-9 decreases MC proliferation in vivo. Membrane insertion of sublytic quantities of the membrane attack complex of complement (C5b-9) is a potent stimulus for cell activation and the production of a variety of cytokines, growth factors, oxidants, matrix components, and other nephritogenic molecules. In vivo, a common response of MC to C5b-9--mediated injury is cell proliferation, an event closely linked to matrix expansion and sclerosis. In this study, we tested the hypothesis that C5b-9 might also serve as a mitogenic stimulus for MCs.
Methods:
Rat MCs in vitro were exposed anti-Thy1 antibody and 2% normal PVG serum (a complement source) to induce sublytic C5b-9 attack and DNA synthesis and cell number were measured. Control MCs were exposed to antibody and C6-deficient PVG serum.
Results:
Sublytic C5b-9--induced injury to MCs is sufficient to induce DNA synthesis. Furthermore, C5b-9 augmented DNA synthesis induced by platelet-derived growth factor (PDGF) and 5% fetal calf serum. C5b-9--induced DNA synthesis was reduced by inhibiting reactive oxygen species (ROS) with superoxide dismutase and catalase, but not by neutralizing the mitogenic growth factors PDGF and basic fibroblast growth factor (bFGF).
Conclusions:
This study demonstrates that C5b-9 may directly increase DNA synthesis in cultured MCs, which are mediated in part by the release of ROS, and that C5b-9 also augments DNA synthesis induced in MCs by other known mitogens.
Insights
The membrane attack complex (C5b-9) directly stimulates mesangial cell (MC) DNA synthesis, partly via reactive oxygen species (ROS). C5b-9 also enhances MC proliferation induced by other growth factors, suggesting a role in glomerular diseases.
Area of Science:
- Nephrology
- Immunology
- Cell Biology
Background:
- Immune-mediated glomerular diseases involve mesangial cell (MC) proliferation.
- The complement system's membrane attack complex (C5b-9) injures kidney cells.
- Inhibiting C5b-9 reduces MC proliferation in vivo.
Purpose of the Study:
- To investigate if C5b-9 acts as a mitogenic stimulus for MCs.
- To determine the mechanisms by which C5b-9 affects MCs.
Main Methods:
- Rat MCs were treated with anti-Thy1 antibody and normal serum to induce C5b-9 attack.
- DNA synthesis and cell number were measured.
- Inhibition of reactive oxygen species (ROS) and growth factors was assessed.
Main Results:
- Sublytic C5b-9 induced DNA synthesis in MCs.
- C5b-9 augmented DNA synthesis stimulated by platelet-derived growth factor (PDGF) and fetal calf serum.
- ROS inhibition reduced C5b-9-induced DNA synthesis, while growth factor neutralization did not.
Conclusions:
- C5b-9 directly increases DNA synthesis in cultured MCs, partly through ROS release.
- C5b-9 amplifies DNA synthesis triggered by other known mitogens in MCs.
