|HRABIA, ANN - Agricultural University Of Poland|
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/31/2022
Publication Date: 4/9/2022
Citation: Hrabia, A., Miska, K.B., Schreier, L.L., Proszkowiec-Wegla, M.K. 2022. Altered gene expression of selected matrix metalloproteinase system proteins in the broiler chicken gastrointestinal tract during post-hatch development and coccidia infection. Poultry Science. https://doi.org/10.1016/j.psj.2022.101915.
Interpretive Summary: The goal of our study was to investigate the expression of genes and proteins that function in processing the extracellular matrix in the intestinal tract of normally developing chickens, and those under stressful conditions like delay in access in feed, and infection of the gastrointestinal tract. The extracellular matrix is very important for proper functioning of organs because it serves as a scaffold for organ specific cells allowing for cell to cell communication, separation between tissues, and biochemical processes. Broiler chickens are grown primarily for meat production, and in most cases, newly hatched chickens do not have access to feed for up to 72 hrs. This practice is due to uneven hatching times, the process of sexing and vaccinating chicks, as well as transport to grow-out facilities. Once placed in farms the young birds encounter other stressors, like exposure to pathogens. In most poultry farms the presence of Eimeria parasite in poultry litter is endemic. These parasites invade the cells of the gastrointestinal tract, causing decrease in weight gain, diarrhea, anorexia, which result in economic losses to the poultry farmer. Stressful conditions such as delay in access to feed and infections of the gastrointestinal tract can lead to disturbances and changeover of the extracellular matrix, and the cellular machinery which controls it. In the current research we determined that most of the genes encoding proteins that modify the extracellular matrix decreased over time, and the delay in access to feed did not significantly affect the expression. Using microscopic tissue sections were we able to localize these proteins in the muscle layers, villi, and blood vessels of the small intestine. In chickens that were infected with Eimeria parasites, the intestine showed significant changes in gene expression at days 7 and 10 after infection. Both increases and decreases in gene expression were observed. During Eimeria infection the tissues of the intestine are disrupted by the parasite invasion, so it is not surprising that the components of the system that regulate the extracellular matrix undergo changes. Further research is needed to determine the exact nature of these changes.
Technical Abstract: Matrix metalloproteinases (MMPs) are a family of proteases, that can process extracellular matrix (ECM) components and non-ECM molecules. MMPs can also function intracellularly in proteolytic and nonproteolytic functions. The participation of MMPs in the remodeling of the chicken gastrointestinal tract is largely unknown. The aim of the present study was to examine (1) the early neonatal developmental changes and effect of delayed access to feed immediately post-hatch (PH) and (2) the effect of Eimeria infection on mRNA expression of selected MMPs, their tissue inhibitors (TIMPs), and ADAM metallopeptidase with thrombospondin type 1 motif 8 (ADAMTS8) in the gastrointestinal tract of chicken. In addition, MMP and TIMP proteins were localized in the ileal wall by immunofluorescence. In experiment 1, newly hatched Ross 708 chicks received feed and water immediately PH or were subjected to 48 h delayed access to feed. Chickens were sampled at -48, 0, 4, 24, 48, 72, 96, 144, 192, 240, 288, and 336 h PH. Ileum was collected for investigation of gene expression or fixed in paraformaldehyde for immunofluorescence. In experiments 2 and 3, Ross 708 male broilers were infected, at 21 d of age with Eimeria maxima or E. acervulina or sham-infected with water. Intestinal tissues were collected at 7 and 10 d post-infection for gene expression analysis. In general, mRNA expression patterns of all examined genes showed downregulation during the first 2 wk PH and were not affected by delay in feed access. This degree of development-dependent changes in expression and tissue-dependent localization in the ileum of selected MMPs and TIMPs point to the significance of these molecules in the orchestration of chicken intestinal tissue turnover during PH development. Overexpression of MMP-7 and MMP-9 transcripts in the intestine of Eimeria infected birds suggests an important role for these enzymes in the process of tissue remodeling and destruction in pathological conditions. The findings of this study are important for understanding the relationship between the expression of the MMP system and intestinal development, as well its role in gastrointestinal infection and subsequent recovery.