Hypoxia Associated Proteolytic Processing of OS-9 by the Metalloproteinase Meprin β

Figure 4

Meprin B cleaves kidney OS-9 in ischemia reperfusion, immunoblot for OS-9 in individual kidney samples. (a) Representative immunoblot for OS-9 in cytosolic-enriched kidney protein fractions from mice subjected to IR-induced renal injury and sham-operated controls. 12-week-old wild-type (WT) and meprin αβ knockout (αβKO) mice were subjected to IR-induced renal injury by clamping of renal pedicle for 26 minutes followed by 6 h of reperfusion. Western blot analysis was used to evaluate fragmentation of OS-9 in cytosolic-enriched kidney protein fractions. Fragmentation of OS-9 was observed in kidney proteins from WT mice subjected to IR, but not in sham-operated WT controls or meprin αβKO mice subjected to IR. A unique (~60 KDa) OS-9 fragment was observed in protein samples from WT kidneys subjected to IR. (b) Blood urea nitrogen (BUN) levels were used as a biochemical assessment of kidney injury. ; .

(a)

(b)