Novel Observations of Peroxiredoxin-2 Profile and Protein Oxidation in Skeletal Muscle From Pigs of Differing Residual Feed Intake and Health Status

Steven M. Lonergan,Edward M. Steadham,Amanda C. Outhouse,Kent J. Schwartz,Elisabeth Huff-Lonergan,Emma T. Helm,Jack C. M. Dekkers,Nicholas K. Gabler,Brian M. Patterson,Logan Johnson

doi:10.22175/mmb.12241

Abstract

This study’s objective was to determine the impact of a dual respiratory and enteric bacterial health challenge on the antioxidant protein peroxiredoxin-2 (Prdx-2) profile and protein oxidation in the skeletal muscle of pigs from 2 lines that were divergently selected for residual feed intake (RFI). The hypotheses were that (1) differences exist in the Prdx-2 profile between 2 RFI lines and infection status and (2) muscle from less efficient high-RFI and health-challenged pigs have greater cellular protein oxidation. Barrows (50 ± 7 kg, N = 24) from the 11th generation of the high-RFI (n = 12) and low-RFI (n = 12) Iowa State University lines were used. Pigs (n = 6 per line) were inoculated with Mycoplasma hyopneumoniae and Lawsonia intracellularis (MhLI) on day 0 post infection to induce a respiratory and enteric health challenge. Uninoculated pigs served as controls (n = 6 per line). Necropsy was at 21 d post infection. Sarcoplasmic protein oxidation, various forms of Prdx-2, and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) content were determined. Neither RFI line nor infection status significantly affected protein carbonylation. Under nonreducing conditions, MhLI pigs had a greater amount of a slower-migrating GAPDH band (P = 0.017), indicating oxidative modification. Regardless of health status, the low-RFI pigs had less total Prdx-2 (P = 0.035), Prdx-2 decamer (P = 0.0007), and a higher ratio of hyperoxidized peroxiredoxin relative to Prdx-2 (P = 0.028) than the high-RFI pigs. The increased pool of active Prdx-2 in high-RFI pigs suggests greater oxidative stress in muscle in high- versus low-RFI pigs. The increase in oxidized GAPDH seen in muscle from MhLI pigs—particularly the high-RFI MhLI pigs—may be a response to the greater oxidative stress in the high-RFI MhLI. This work suggests that antioxidant proteins are important in growth and health-challenge situations.

Highlights

Improving the efficiency of pork production is paramount as the global demand for animal protein increases
The hypotheses were that (1) differences exist in the Prdx-2 profile based on residual feed intake (RFI) line and infection status and (2) more protein oxidation occurs in longissimus muscle from less efficient HRFI and health-challenged pigs
A trend was seen for an interaction between RFI line and infection status (P = 0.064), with carbonyl content being greater in LRFI Mycoplasma hyopneumoniae and Lawsonia intracellularis (MhLI) pigs than LRFI control pigs and lower in HRFI MhLI pigs compared with HRFI controls (Table 3)

Summary

Introduction

Improving the efficiency of pork production is paramount as the global demand for animal protein increases. More indepth research is needed to improve understanding of the physiological balance between oxidative stress, health-challenge response, and feed efficiency. No study has compared the various Prdx-2 oxidation states and oligomeric structures in the skeletal muscle of livestock that differ in feed efficiency or under a health challenge. This study’s objective was to determine the impact of dual infection with M. hyopneumoniae and L. intracellularis (MhLI) on Prdx-2 protein profile and oxidation of sarcoplasmic proteins in the skeletal muscle of pigs from lines that were divergently selected for RFI. The hypotheses were that (1) differences exist in the Prdx-2 profile based on RFI line and infection status and (2) more protein oxidation occurs in longissimus muscle from less efficient HRFI and health-challenged pigs

Materials and Methods

Results and Discussion

Literature Cited