|MARTINEZ, A - Crilar-Conicet: Regional Research Centre La Rioja|
Submitted to: Symposium on Gut Health in Production of Food Animals
Publication Type: Abstract Only
Publication Acceptance Date: 9/20/2016
Publication Date: N/A
Technical Abstract: Activation of pathogen-sensing mechanisms in intestinal cells initiate the generation of pathway effectors that perturb normal nutritional enterocyte (ETC) functions. Among the conserved pathway mediator molecules generated are nitric oxide (NO) and superoxide anion (SOA) which are known to interact forming ONOO- and ONO2CO2- , each of which can form 3'-nitrotyrosine proteins (NTp). Nitrotyrosine proteins are associated with significant inhibition of protein function, apoptosis and cell death. We undertook the present study to establish the temporal dynamics of potential nitration reactions in the ETCs of broiler chickens in response to infection with Eimeria acervulina. Ross Heritage broilers (n=4/time point) were either maintained as non-infected (NI) or infected with 3 x 105 E. acervulina oocysts per bird. Duodenal tissue was harvested on days (D) 0, 1, 3, 6, 7 and 10 post-infection (PI) and fixed, embedded, and sectioned for analysis by quantitative immunohistochemistry with antibodies specific to NTp and the enzymes xanthine oxidase (XO, SOA generator) and inducible nitric oxide synthase (iNOS, NO generator). Photomicrographs were analyzed for specific pixel quantification using Media Cybernetics Image-Pro 9.2. Accumulation/content of the respective antigenic epitopes was specified by outlining and capturing areas of interest (AOIs) representative of ETCs. Data were statistically analyzed using a mixed models procedure in SAS. NTp, iNOS and XO increases were evident in intestinal villi as early one day PI (P<0.05 v NI) and specific to enterocytes (P<0.02). The increases in NTp, iNOS, and XO (number of positive cells and pixel content/cell) occurred in a defined pattern, significant by villus location for day of infection, initiating in the distal villus region progressing down into the proximal villus, and further into the crypts largely mirroring the presence of Eimeria down the villus. Two NT patterns were observed in ETCs: a generalized increase (3-fold > NI) and the 8-fold higher levels associated with cells harboring nitrated parasites. The data suggest that the ETC NT response may mediate some of the cytotoxic processes that limit the progress of Eimeria infection.