Abstract
Background: Sepsis is one of the most frequent causes of death in the ICU, and microvascular hyperpermeability caused by oxidative/nitrosative stress plays an important role in tissue edema leading to multi-organ dysfunctions and increased mortality. This study tested the efficacy of a novel compound R-107, a modulator of oxidative/nitrosative stress, in an ovine model of sepsis. We hypothesized that R-107 effectively ameliorates the severity of microvascular hyperpermeability and preserves multi-organ function.Methods: Sepsis was induced in twenty-two adult female Merino sheep by intravenous infusion of Pseudomonas aeruginosa (1x1010 CFUs) for 60 minutes. After injury, animals were allocated into the following groups: 1) Control: intramuscular injection (IM) of saline, n=13; and 2) Treatment: IM of 50 mg/kg R-107, n=9. The IM treatment was given after the completion of the Pseudomonas aeruginosa injection. Animals were placed on a mechanical ventilator, fluid resuscitated, and monitored for 24 hours in a conscious state. Results: R-107 treatment attenuated 24-hour mortality (11 vs. 30%). R-107 significantly reduced fluid requirement (15 – 24 hours, p<0.05), net fluid balance (9 – 24 hours, p<0.05), and water content in lung, heart, and kidney (p=0.02, 0.04, and 0.01, respectively) compared to control. R-107 treatment significantly delayed the onset of positive qSOFA (3.3 vs. 6.8 hours, p=0.04), and significantly decreased lung injury score and modified sheep SOFA score at 24 hours (p=0.01 and 0.04). The R-107 treatment group had significantly lower arterial lactate (21 – 24 hours, p<0.05), shed syndecan-1 (3 – 6 hours, p<0.05), and interleukin-6 (6 – 12 hours, p<0.05) levels in plasma, and significantly attenuated lung tissue 3-nitrotyrosine and vascular endothelial growth factor-A expression (p=0.03 and 0.002) compared to control. There was no adverse effect observed during R-107 treatment.Conclusions: Modulation of oxidative/nitrosative stress by R-107 reduced lung tissue vascular endothelial growth factor-A, plasma shed syndecan-1, and interleukin-6 and attenuated severe microvascular hyperpermeability resulting in improved multi-organ function and survival in Pseudomonas aeruginosa sepsis.
HSP22 (HSPB8) positively regulates PGF2α-induced synthesis of interleukin-6 and vascular endothelial growth factor in osteoblasts
