Myeloperoxidase is critically involved in the induction of organ damage after renal ischemia reperfusion.
In this study the role of myeloperoxidase (MPO) in a murine (C57BL/6) model of ischemia and reperfusion (I/R)-induced renal failure was investigated. The renal function after I/R was analyzed in MPO-deficient (Mpo(-/-)) mice and compared with wild-type (WT) controls. A significant reduction in renal function loss (blood urea nitrogen) was observed after 24 hours of reperfusion of ischemically damaged kidneys in Mpo(-/-) mice compared with I/R WT controls (I/R Mpo(-/-) = 31.3 +/- 1.7 mmol/L versus I/R WT = 42.8 +/- 2.1 mmol/L, sham = 7.0 +/- 0.5 mmol/L; P = 0.003). The early reperfusion phase (2 hours of reperfusion) was characterized by a substantial increase in apoptosis and early complement activation, surprisingly similar in Mpo(-/-) and WT mice. Improved renal function in Mpo(-/-) mice after extended reperfusion was accompanied by a reduced neutrophil influx (P = 0.017) compared with WT controls. Activation and deposition of complement was not significantly reduced in Mpo(-/-) mice compared with WT controls after 24 hours of reperfusion, indicating no specific in vivo role for MPO in activating complement after renal I/R. Taken together, these results demonstrated an important contribution of MPO in the induction of organ damage after renal I/R by influencing critical factors such as neutrophil extravasation but not complement activation.
Department of General Surgery, Research Institute Maastricht, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands.
Robert A
RA
Matthijsen
Dennis
D
Huugen
Nicole T
NT
Hoebers
Bart
B
de Vries
Carine J
CJ
Peutz-Kootstra
Yasuaki
Y
Aratani
Mohamed R
MR
Daha
Jan Willem Cohen
JW
Tervaert
Wim A
WA
Buurman
Peter
P
Heeringa
D000818:Animals; D017209:Apoptosis / Q000235:genetics; D003167:Complement Activation / Q000235:genetics; D007674:Kidney Diseases / Q000201:enzymology / Q000276:immunology / Q000473:pathology*; D051379:Mice; D008817:Mice, Mutant Strains; D009504:Neutrophils / Q000276:immunology; D009195:Peroxidase / Q000235:genetics / Q000502:physiology*; D015427:Reperfusion Injury / Q000201:enzymology / Q000276:immunology / Q000473:pathology*
D009195:Peroxidase