SCUBE1, a novel developmental gene involved in renal regeneration and repair.
BACKGROUND
We have identified that a novel developmental gene and protein, SCUBE1, is expressed in endothelial cells and may play an important role in kidney regeneration.


METHODS
The temporal and spatial expression of SCUBE1 was determined in a mouse model of ischaemia-reperfusion (IR) injury at 3 days and 1, 3 and 6 weeks post-injury by immunofluorescence microscopy. In vitro analysis was used to examine SCUBE1 signalling in endothelial cells under conditions of cell stress using quantitative real-time polymerase chain reaction and immunofluorescence labelling. The media from cultured endothelial cells following SCUBE1 small interfering RNA (siRNA) transfection was used to assess the proliferation capacity of epithelial cells.


RESULTS
Immunofluorescence confocal microscopy demonstrated that the SCUBE1 protein was localized to CD31-positive endothelial cells in IR kidneys during the resolution of tissue damage (3 weeks), but not in control animals. The peak expression of SCUBE1 following 3 weeks of IR injury was confirmed by reverse transcription-polymerase chain reaction. SCUBE1 mRNA and protein expression were detected in cultured endothelial cells under hypoxic conditions or serum starving. Furthermore, there was a significant decrease in epithelial cell proliferation following the addition of a supernatant derived from cultured endothelial cells following SCUBE1 siRNA gene silencing compared to control media.


CONCLUSIONS
Our results indicate that SCUBE1 may be involved in the regulation of tubular cell proliferation and re-epithelialization during the resolution of kidney injury.
Zhuang
Junli
J
Monash Immunology and Stem Cell Laboratories, Monash University and the Australian Stem Cell Centre, Clayton, Victoria, Australia.
Deane
James Antony
JA
Yang
Ruey-Bing
RB
Li
Jinhua
J
Ricardo
Sharon Denise
SD
D000818:Animals; D002135:Calcium-Binding Proteins; D015687:Cell Hypoxia; D049109:Cell Proliferation; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000502:physiology; D036341:Intercellular Signaling Peptides and Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D007668:Kidney / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D034741:RNA, Small Interfering / Q000235:genetics; D012038:Regeneration; D015427:Reperfusion Injury / Q000473:pathology
D002135:Calcium-Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; D034741:RNA, Small Interfering; C417547:Scube1 protein, mouse