332 Role of Kynurenine/Tryptophan Ratio in Kidney-Lung crosstalk in two porcine trauma-induced multi-organ injury models

Abstract

OBJECTIVES/GOALS: Multiple Organ Failure, often precipitated by Acute Lung Injury, is a life-threatening condition that causes death in military and civilian life. Furthermore, Acute Kidney Injury is very common, increasing morbidity and mortality rates. Therefore, understanding the molecular difference between survivors and non-survivors is urgently needed. METHODS/STUDY POPULATION: A 24-hour unilateral pulmonary contusion porcine model (pneumonectomy) of trauma-induced Multiple Organ Failure (MOF) model (n=17) and separate 48-hour polytrauma injury of bilateral pulmonary contusion, traumatic brain injury, and hemorrhage (polytrauma) MOF model (n=26) was developed at Dr. Batchinsky's AREVA laboratory. Serum was assayed at baseline and 3h or 6h post-trauma for amino acid metabolites using the Zip-Chip platform for mass spectrometry. The IDO1 enzyme activity assay kit (ab235936) was used to measure IDO1 enzyme activity in the tissue. Mass Spectrometry Imaging (MSI) was employed to frozen kidney tissues. Tissues were sectioned to 10- micron thickness. For MSI, the DAN matrix was utilized, and MALDI-MSI images were processed and obtained from METASPACE and SCILS software. RESULTS/ANTICIPATED RESULTS: In the pneumonectomy model, 10 survived, 7 died, and in the polytrauma group, 13 survived, and 13 died. In the pneumonectomy model, there was a significant increase in the serum kynurenine/tryptophan (KYN/TRP) ratio in the non-survivors 3h post-injury. A similar pattern was found in the validation group, which showed a significant increase in the KYN/TRP ratio at 6h post-trauma in non-survivors from the polytrauma model. There was a significant increase in IDO1 enzyme activity in non-survivor kidney tissues and a downregulation of tryptophan (TRP) metabolite in the kidney section in the non-survivor group post-trauma. DISCUSSION/SIGNIFICANCE: An increase in the KYN/TRP ratio post-trauma identified the pigs that suffered early mortality. A decrease in TRP metabolite and an increase in IDO1 enzyme activity in the kidney could contribute to an increase in KYN in the non-survivors. As a result, focusing on therapeutics targeting the KYN/TRP to reduce the incidence and severity of MOF is warranted.