[HTML][HTML] CSF-1 signals directly to renal tubular epithelial cells to mediate repair in mice

J Menke, Y Iwata, WA Rabacal, R Basu… - The Journal of …, 2009 - Am Soc Clin Investig
J Menke, Y Iwata, WA Rabacal, R Basu, YG Yeung, BD Humphreys, T Wada, A Schwarting
The Journal of clinical investigation, 2009Am Soc Clin Investig
Tubular damage following ischemic renal injury is often reversible, and tubular epithelial cell
(TEC) proliferation is a hallmark of tubular repair. Macrophages have been implicated in
tissue repair, and CSF-1, the principal macrophage growth factor, is expressed by TECs. We
therefore tested the hypothesis that CSF-1 is central to tubular repair using an acute renal
injury and repair model, ischemia/reperfusion (I/R). Mice injected with CSF-1 following I/R
exhibited hastened healing, as evidenced by decreased tubular pathology, reduced fibrosis …
Tubular damage following ischemic renal injury is often reversible, and tubular epithelial cell (TEC) proliferation is a hallmark of tubular repair. Macrophages have been implicated in tissue repair, and CSF-1, the principal macrophage growth factor, is expressed by TECs. We therefore tested the hypothesis that CSF-1 is central to tubular repair using an acute renal injury and repair model, ischemia/reperfusion (I/R). Mice injected with CSF-1 following I/R exhibited hastened healing, as evidenced by decreased tubular pathology, reduced fibrosis, and improved renal function. Notably, CSF-1 treatment increased TEC proliferation and reduced TEC apoptosis. Moreover, administration of a CSF-1 receptor–specific (CSF-1R–specific) antibody after I/R increased tubular pathology and fibrosis, suppressed TEC proliferation, and heightened TEC apoptosis. To determine the contribution of macrophages to CSF-1–dependent renal repair, we assessed the effect of CSF-1 on I/R in mice in which CD11b+ cells were genetically ablated and determined that macrophages only partially accounted for CSF-1–dependent tubular repair. We found that TECs expressed the CSF-1R and that this receptor was upregulated and coexpressed with CSF-1 in TECs following renal injury in mice and humans. Furthermore, signaling via the CSF-1R stimulated proliferation and reduced apoptosis in human and mouse TECs. Taken together, these data suggest that CSF-1 mediates renal repair by both a macrophage-dependent mechanism and direct autocrine/paracrine action on TECs.
The Journal of Clinical Investigation