Perfusion of kidneys with unformulated 'naked' intercellular adhesion molecule-1 antisense oligodeoxynucleotide s prevents ischemic/reperfusion injury

Background. We have previously shown that phosphorothioate intercellular adhesion molecule (ICAM)-1 antisense oligodeoxynucleotide (oligo) IP-9125 blocks the expression of rat ICAM-1 mRNA in rat L2 cells. A single ex situ perfusion of grafts with unformulated IP-9125, suspended in Euro-Collins solution, prolonged the survival of kidney allografts in rats. The present experiments examined whether perfusion of kidneys with unformulated IP-9125 prevents ischemic/reperfusion injury. Methods. Kidneys were perfused ex situ with 2 ml of Euro-Collins solution without or with IP-9125 and exposed to 30- min cold (4 °C storage time) and 30-min warm (anastomosis time) ischemia. Kidneys were then transplanted to syngeneic nephrectomized recipients. Results. Within 24 hr after transplantation, the glomerular filtration rate values were reduced by almost 60% to 0.49 ± 0.14 ml/min from 1.20 ± 0.27 ml/min in normal kidneys (P < 0.001). Kidney perfusion with 10 mg of either IP-12140 (0.41 ± 0.07 ml/min) or IP-13944 (0.47 ± 0.07 ml/min) control oligo was ineffective. In contrast, perfusion with 10 mg of IP-9125 significantly improved kidney function (0.8 ± 0.18 ml/min; P < 0.005), whereas the lower doses of 2 mg (0.47 ± 0.13 ml/min; NS) or 4 mg (0.54 ± 0.04 ml/min; NS) had no significant effect. The glomerular filtration rate results were confirmed by measurements of blood creatinine (CR) levels at 24 hr after grafting: untreated recipients had a twofold higher CR value (0.70 ± 0.14 mg/dl) compared with normal controls (0.65 ± 0.07 mg/dl; P < 0.001). Although perfusion with 10 mg of control IP-12140 (0.80 ± 0.14 mg/dl) or IP- 13944 (0.65 ± 0.07 mg/dl) did not affect CR levels, perfusion with 10 mg of IP-9125 (0.45 ± 0.07 mg/dl) lowered CR levels. The Western blots or reverse transcription-polymerase chain reaction experiments performed in kidney transplants within 24 hr after grafting showed that 10 mg of IP-9125 (but not control IP-12140) reduced the expression of ICAM-1 protein and ICAM-1 mRNA, respectively. Conclusions. Perfusion of grafts with unformulated ICAM-1 antisense oligo specifically reduces intragraft ICAM-1 protein expression and prevents ischemic/reperfusion injury.