Immobilized kidney 28-kDa endostatin-related (KES28kDa) fragment promotes endothelial cell survival.
OBJECTIVE
Renal ischemia-hypoxia is a leading cause of acute kidney injury (AKI). Ischemia causes extracellular matrix breakdown of the tubular basement membrane. Endostatin (ES) is the C-terminal fragment of collagen XVIII generated by proteolytic cleavage. Recent studies have demonstrated that ES expression is upregulated in ischemic kidneys. The present study aimed to characterize ES from ischemic kidneys.


METHODS
Ischemic renal failure was induced via 45 min of occlusion of the left renal artery and vein. After the ischemic period, blood was collected. Kidneys were harvested and used for immunohistochemical testing and protein extraction. Three-step purification was used. Soluble and immobilized purified ES were tested in cell viability and adhesion assays. results: The soluble KES28kDa inhibited endothelial cell proliferation: 25 versus 12.5 microg (p < 0.05); 12.5 versus 3.15 microg (p < 0.05). Immobilization of KES28kDa supports endothelial cell survival over the control (p = 0.021). Human umbilical vein endothelial cells plated on immobilized KES28kDa showed an increase in membrane ruffles and stress fibers.


CONCLUSIONS
These data demonstrate the local synthesis of a 28-kDa ES-related fragment following AKI and suggest its role in endothelium survival.
Bellini
Maria Helena
MH
Center of Biotechnology, Energy and Nuclear Research Institute - IPEN, Universidade Federal de São Paulo, Brazil. mhmarumo@terra.com.br
Malpighi
Thiago França
TF
Calvo
Fernanda Bernardes
FB
Miranda
Adriana Regina
AR
Spencer
Patrick Jack
PJ
Cichy
Milena Cristina
MC
Simons
Simone Michaela
SM
Chudzinski Tavassi
Ana Marisa
AM
Fagundes dos Santos
Marinilce
M
Junqueira Rodrigues
Consuelo
C
Schor
Nestor
N
D058186:Acute Kidney Injury / Q000378:metabolism* / Q000473:pathology*; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D004195:Disease Models, Animal; D043169:Endostatins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D055767:Immobilized Proteins; D007150:Immunohistochemistry; D007511:Ischemia / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D007677:Kidney Function Tests; D051379:Mice; D008810:Mice, Inbred C57BL; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012995:Solubility; D022502:Stress Fibers / Q000378:metabolism; D014471:Umbilical Veins / Q000166:cytology
D043169:Endostatins; D055767:Immobilized Proteins; D010446:Peptide Fragments; D012333:RNA, Messenger