CHARACTERIZATION OF THE PLASMA AND SYNOVIAL FLUID PROTEOMES IN YEARLING HORSES FED HIGH OR LOW STARCH FEED

Open Access
- Author:
- Nowelsky, Erin Ashley
- Graduate Program:
- Animal Science
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- March 26, 2010
- Committee Members:
- William Staniar, Thesis Advisor/Co-Advisor
William Staniar, Thesis Advisor/Co-Advisor - Keywords:
- osteochondrosis
nutrition
horse
cartilage
proteomics - Abstract:
- The primary objective of this study was to characterize the plasma and synovial fluid proteomes using 2D PAGE and isolate and identify proteins that exhibit large differences in their relative abundance and may play a role in the pathology of osteochondrosis (OC). A second objective was to estimate cartilage metabolism by quantifying biomarkers CPII, C2C and IGF – I to determine differences in anabolism and catabolism between dietary treatment groups differing in relative starch availability. Six yearlings, maintained on dry lot and were provided ad libitum access to <5% starch hay, were used in a crossover study design conducted over 12 weeks with four 21 day treatment periods. During periods 2 and 4, yearlings were split into 2 groups, with one group receiving high starch feed (~40% starch on a DM basis) and the other group receiving low starch feed (<10% starch on a DM basis). All yearlings received low starch feed in periods 1 and 3. Synovial fluid and plasma samples were collected every 21 days and analyzed using 2D PAGE and CPII, C2C and IGF – I specific ELISAs. Gel images were analyzed using Progenesis SameSpots software and select spots were chosen for mass spectrometry based on their level of significance and relationship to dietary treatment. Changes in protein expression ranged from a 1.2 fold – 2.5 fold difference. Seven proteins were upregulated in response to dietary treatment. Four of the 7 proteins, identified as isoforms of IgG, were greater in synovial fluid from animals fed high starch feed. Two proteins, identified as isoforms of albumin, were greater in high starch feed samples. Fibrinogen, haptoglobin, vitamin D binding protein and clusterin were greater in plasma compared to synovial fluid. Alpha-1 antitrypsin and albumin were greater in synovial fluid compared to plasma. There were no significant differences in C2C or IGF – I between dietary treatments. Proteins identified in this study initially do not have a clear mechanistic link with OC. This study demonstrates an approach that may be useful in investigating changes in protein expression in plasma and synovial fluid that may affect joint health. The plasma and synovial fluid proteomic profiles and individual proteins identified here may be useful in future examination of the etiology of OC in horses.