Proteomic analysis reveals changes in carbohydrate and protein metabolism associated with broiler breast myopathy.

White Striping (WS) and Woody Breast (WB) are 2 conditions that adversely affect consumer acceptance as well as quality of poultry meat and meat products. Both WS and WB are characterized with degenerative myopathic changes. Previous studies showed that WS and WB in broiler fillets could result in higher ultimate pH, increased drip loss, and decreased marinade uptake. The main objective of the present study was to compare the proteomic profiles of muscle tissue (n = 5 per group) with either NORM (no or few minor myopathic lesions) or SEV (with severe myopathic changes). Proteins were extracted from these samples and analyzed using a hybrid LTQ-OrbitrapXL mass spectrometer (LC-MS/MS). Over 800 proteins were identified in the muscle samples, among which 141 demonstrated differential (P < 0.05) expression between NORM and SEV. The set of differentially (P < 0.05) expressed proteins was uploaded to Ingenuity Pathway Analysis® (IPA) software to determine the associated biological networks and pathways. The IPA analysis showed that eukaryotic initiation factor-2 (eIF-2) signaling, mechanistic target of rapamycin (mTOR) signaling, as well as regulation of eIF4 and p70S6K signaling were the major canonical pathways up-regulated (P < 0.05) in SEV muscle compared to NORM. The up-regulation of these pathways indicate an increase in protein synthesis which could be part of the rapid growth as well as cellular stress associated with ongoing muscle degeneration and the attempt to repair tissue damage in SEV birds. Furthermore, IPA analysis revealed that glycolysis and gluconeogenesis were the major down-regulated (P < 0.05) canonical pathways in SEV with respect to NORM muscle. Down-regulation of these pathways could be the reason for higher ultimate pH seen in SEV muscle samples indicating reduced glycolytic potential. In conclusion, comparison of proteomic profiles of NORM and SEV muscle samples showed differences in protein profile which explains some of the observed differences in meat quality parameters. Future studies based on these differences could provide valuable insights into various cellular changes and identification of biomarkers related to WS and WB.