Cardiotrophin-1 Attenuates Endotoxin-Induced Acute Lung Injury

Abstract

Cardiotrophin-1 (CT-1) is a recently discovered member of the gp130 cytokine family, which includes IL-6, IL-11, leukemia inhibitory factor, ciliary neurotrophic factor, and oncostatin M. Recent evidence suggests that, like other members of this family, CT-1 may possess anti-inflammatory properties. We hypothesized that in vivo CT-1 administration would attenuate endotoxin (ETX)-induced acute lung injury. We studied the effects of CT-1 (100 μg/kg ip, 10 min prior to ETX) in a rat model of ETX-induced acute lung injury (Salmonella typhimurium lipopolysaccharide, 20 mg/kg ip). Six hours after ETX, lungs were harvested for determination of neutrophil accumulation (myeloperoxidase, MPO, assay) and lung edema (wet-to-dry weight ratio). Mechanisms of pulmonary vasorelaxation were examined in isolated pulmonary artery rings at 6 h by interrogating endothelium-dependent (response to acetylcholine) and endothelium-independent (response to sodium nitroprusside) relaxation following α-adrenergic (phenylephrine)-stimulated preconstriction. CT-1 abrogated the endotoxin-induced lung neutrophil accumulation: 2.3 ± 0.2 units MPO/g wet lung (gwl) vs 6.3 ± 0.3 units MPO/gwl in the ETX group (P < 0.05 vs ETX, P > 0.05 vs control). Similarly, CT-1 prevented ETX-induced lung edema: wet-to-dry-weight ratio, 4.473 ± 0.039 vs 4.747 ± 0.039 in the ETX group (P < 0.05 vs ETX, P > 0.05 vs control). Endotoxin caused significant impairment of both endothelium-dependent and -independent pulmonary vasorelaxation, and CT-1 attenuated this injury. Thus, cardiotrophin-1 possesses significant anti-inflammatory properties in a model of endotoxin-induced acute lung injury.