Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 4/21/2012
Publication Date: 7/14/2012
Citation: Elsasser, T.H., Kahl, S., Castellano-Perez, R., Li, C., Block, S. 2012. Effects of short-term tocopherol (T) feeding on structure-localized protein tyrosine nitration (pTN) patterns of mitochondrial ATPase following endotoxin (LPS) challenge in beef calves. Journal of Animal Science. 88 (Suppl. 2):591. Interpretive Summary:
Technical Abstract: Mitochondrial ATPase/Complex-V (MCV) is an electron transport chain (ETC) component needed for ATP synthesis. The ETC, exquisitely sensitive to proinflammatory mediators (PIM), generates oxynitrogen reactants leading to pTN formation as mitochondrial membrane leakage occurs. Immunohistochemical localization (IHC-L) of pTN (a biomarker of pTN damage to proteins) in liver following LPS suggests that pTN responses to PIM are not uniform across liver structures. Furthermore, because of their respective oxynitrogen reactivities, a-T and '-T may differentially affect pTN formation in cells. Our objective was to determine the effects of 5-d feeding of supplemental a-T (A, Novatol™ 1490, ADM; T content (%): a = 98.2, ' < 1) or '-T (G, Decanox™ MTS-90 G, ADM; T content (%): a = 10, ' = 69) on the nitration of MCV in central venous (CV), portal triad (PT), and hepatocyte/paranchymal (HP) areas of the liver after LPS challenge (0.25 µg/kg BW, i.v.). Beef calves (n = 21; 211 ± 6 kg) were penned and fed in equal numbers one of three test diets: control (C, no supplement), A (Novatol™ = 1.25 g/calf/d), or G (Decanox™ = 3.85 g/calf/d). Liver biopsy samples were obtained at -24 and +24 h relative to LPS injection. The MC-V was measured by quantitative IHC-L and MC-V nitration analyzed by proximity ligation assay (PLA™, Olink Biosciences, Sweden). After LPS, MCV staining increased 4-, 3.4-, and 2-fold (vs. pre-LPS) in C, A, and G, respectively (P < 0.05, effect of T). By structure, MC-V intensities (pixels/cell) were: HP < PT < CV (P < 0.05). With CV as the target structure, PLA™ demonstrated a 5-fold increase (P < 0.05) in colocalized pTN signals associated with MCV after LPS with decreasing (P < 0.05) nitration of MCV in samples where G < A < C. The data are consistent with MCV as a target for nitration after LPS and a protective effect of T against this nitration.