Ubiquitin enhances the Th2 cytokine response and attenuates ischemia-reperfusion injury in the lung.
OBJECTIVE
To determine whether ubiquitin treatment modulates the lung cytokine response and attenuates lung ischemia-reperfusion injury.


METHODS
Randomized and blinded treatment of unilateral lung ischemia-reperfusion injury in a research laboratory.


METHODS
Twenty anesthetized and mechanically ventilated Brown Norway rats.


METHODS
Unilateral clamping of the left lung for 90 mins followed by 60 mins of reperfusion. Intravenous administration of 1.5 mg/kg of ubiquitin (n = 10) or albumin (n = 10) 5 mins before reperfusion.


RESULTS
Blood pressure was measured by the tail-cuff method. Oxygenation via the ischemic lung was assessed by PaO2 measurements after right lung exclusion. Wet-to-dry weight ratios of the ischemic lungs were determined gravimetrically. Tissue homogenates (n = 5/group) were prepared from ischemic lungs at the end of reperfusion and assayed for malondialdehyde in combination with 4-hydroxyalkenals to assess lipid peroxidation, and for a panel of 22 cytokines/chemokines using a multiplex assay. Ubiquitin serum levels were determined by enzyme-linked immunosorbent assay.All animals were hemodynamically stable during the experimental procedure. Ubiquitin serum levels (mean +/- SD) were 650 +/- 40 ng/mL in controls and 1206 +/- 181 ng/mL in the ubiquitin treatment group at the end of the experiment. PaO2 after right lung exclusion was 45 (32-72) mm Hg with albumin and 61 (range, 36-132) mm Hg with ubiquitin (p = .0185). Wet-to-dry weight ratios of the injured lungs were 8.7 (range, 5.5-19.1) and 7.8 (range, 5.7-8.3) in the albumin and ubiquitin groups, respectively (p = .035). Malondialdehyde/4-hydroxyalkenals concentrations (mean +/- SD, nmol/mg protein) were 2.5 +/- 0.4 with ubiquitin and 3.0 +/- 0.3 with albumin (p > .05). Concentrations of the interleukins 4, 10, and 13 were significantly increased in lung homogenates after ubiquitin treatment (p < .05).


CONCLUSIONS
Ubiquitin treatment enhances the Th2 cytokine response in postischemic lungs during reperfusion, reduces lung edema formation, and improves pulmonary function during lung ischemia-reperfusion injury. This study further defines ubiquitin's anti-inflammatory properties, and suggests that it could be used therapeutically to improve function of postischemic lungs.
Garcia-Covarrubias
Lisardo
L
Division of Cardiothoracic Surgery, DeWitt Daughtry Family Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.
Manning
Eddie W
EW
Sorell
Luis T
LT
Pham
Si M
SM
Majetschak
Matthias
M
D000818:Animals; D016207:Cytokines / Q000096:biosynthesis* / Q000187:drug effects; D008168:Lung / Q000098:blood supply*; D008297:Male; D051381:Rats; D011914:Rats, Inbred BN; D015427:Reperfusion Injury / Q000276:immunology / Q000517:prevention & control*; D018418:Th2 Cells / Q000187:drug effects; D025801:Ubiquitin / Q000627:therapeutic use*
D016207:Cytokines; D025801:Ubiquitin