PSII-29 Identification of serum proteins that interact with extracellular histones in feedlot cattle. (5th December 2019)

• Record Type: Journal Article
• Authors: Flores, Victor V; Gifford, Jennifer A Hernandez; Matera, Julia; Hartson, Steven; Wilson, Blake K; Byrum, Stephanie D; Gifford, Craig A
• Is Part Of: Journal of animal science. Volume 97(2019)Supplement 3
• Page Start: 246
• Page End: 246
• Publication Date: 2019-12-05
• Subjects: cattle -- extracellular histones -- histones -- respiratory disease -- toxicity; Livestock -- Periodicals; Livestock; Electronic journals; Periodicals; 636.005
• DOI: 10.1093/jas/skz258.500
• Languages: English
• ISSNs: 0021-8812

Abstract

Abstract: Bovine respiratory disease complex remains the largest challenge facing the cattle industry. Extracellular histones, which are released during disease, have a pathological role in death associated with acute sepsis or respiratory distress syndrome. Treatment against histone cytotoxicity improves survivability of mice suffering from sepsis and respiratory disease. Previously, we demonstrated calves with severe or lethal cases of bovine respiratory disease had an impaired capacity to protect against histone cytotoxicity. However, the mechanism or component of the serum which modulates histone cytotoxicity is unclear. Therefore, the objective of the current study was to identify components in serum which interact with extracellular histones. To achieve this objective serum proteins that interact with histones were precipitated by the addition and incubation of exogenous histones (2.5μg/μL; 1 h; 23°C). Serum protective capacity was determined pre- and post-precipitation, using our novel in-vitro assay and cell viability was estimated using resazurin. Fluorescent values were analyzed using GLM procedure of SAS and means were separated using PDIFF function. Fluorescent values decreased (P < 0.05) after precipitation, indicating interacting proteins were effectively precipitated. Protein from the precipitate was then separated using SDS-PAGE. Proteomes, excluding IgG and BSA, were analyzed by LC-MS/MS using a label-free data-dependent "shotgun" mass spectrometry approach. Proteins were identified and quantified by searching UniProtKB database (restricted to Bos taurus; 32, 967 entries) using Andromeda search engine in MaxQuant. Seven of the top twenty candidate proteins identified were associated with the complement system. Results in the literature suggest that histones play a role in controlling activation of the complement system through binding of complement associated proteins. Results from the current study extend those findings and suggest the complement system may interact with extracellular histones to minimize histone cytotoxicity, indicating aberrant regulation of the complement system or extracellular histones can lead to increased tissue damage during disease.