Effects of manipulation of the caspase system on myofibrillar protein degradation in vitro12

Abstract

Apoptosis via the intrinsic caspase 9 pathway can be induced by oxidative stressors hydrogen peroxide (H₂O₂) and N-(4 hydroxyphenol) rentinamide (fenretinide), a synthetic retinoid. Accelerated muscle atrophy and proteolysis in muscle-wasting conditions have been linked to oxidative stress and activated protease systems. Therefore, the hypothesis of this study was that proteolysis of myofibrillar proteins could be manipulated through the induction or inhibition of the caspase system. After slaughter, LM and supraspinatus muscles from callipyge (n = 5) and normal (n = 3) lambs were excised, finely diced, and incubated with treatment buffers containing oxidative stressors fenretinide or H₂O₂, recombinant caspase 3, caspase-specific inhibitor N-acetyl-Asp-Glu-Val-Asp-CHO (DEVD), or control solution. Muscle samples were incubated for 1, 2, 7, and 21 d at 4°C. Activation of the initiator caspase, caspase 9, and myofibrillar protein degradation was determined by SDS-PAGE and Western blotting. Results showed that fenretinide, H₂O₂, and recombinant caspase 3 increased (P < 0.05) proteolysis of myofibril proteins, whereas DEVD inhibited degradation (P < 0.05). Proteolysis of myofibrillar proteins increased with incubation time (P < 0.0001), and incubation time × treatment interactions (P < 0.05) indicated that the treatment effects did not all occur at the same rate. This study has shown that manipulation of the caspase system through induction or inhibition of activity can affect degradation of myofibrillar proteins, providing further evidence that the caspase system could be involved in postmortem proteolysis and tenderization. However, these stimulated changes were not sufficient to overcome the lack of proteolysis that is characteristic of muscle from callipyge lambs.

Textural and biochemical changes of scallopPatinopecten yessoensisadductor muscle during low-temperature long-time (LTLT) processing

“…[47] Previous researches have revealed that caspase-3 is capable of degrading a number of proteins in muscle. [9,48] In the current study, it is shown that the activities of cathepsin L and caspase-3 were increased by increasing heating time, and the higher level of activity could be sustained after 24 h (Fig. 2B,C), which may lead to the complete degradation of MHC and paramyosins, as shown in Fig.…”

Advances in apoptotic mediated proteolysis in meat tenderisation

“…All three apoptotic inducing treatments examined in this study resulted in a significant increase in caspase 3 activity, and the appearance of a 30 kDa proteolytic product assumed to originate from troponin T degradation and the generation of the caspase specific alpha II spectrin 120 kDa degradation product (SBDP120). Inhibition and activation of the caspase proteolytic system have also been demonstrated in myofibrils isolated from LD and supraspinatus muscles from normal and callipyge sheep (Kemp & Wheeler, 2011). Overall, results showed treatment with apoptotic inducers hydrogen peroxide and fenretinide reduced protein expression of the inactive latent isoform of caspase 9, indicating activation of the intrinsic apoptotic pathway.…”

“…However, whilst treatment with apoptosis inducers fenretinide and hydrogen peroxide, and also recombinant caspase 3 can increase proteolysis in callipyge animals, which exhibit elevated levels of calpastatin, in comparison to control treatment, their effects were not substantial enough to overcome the limited proteolysis that these animals exhibit ( Fig. 3b; Kemp & Wheeler, 2011). The results from these studies accentuate the complexity of post-mortem proteolysis and meat tenderisation, and suggest that further research is required to understand the mechanisms behind it and the interactions between different proteolytic systems.…”

“…Muscle samples were incubated with oxidative stressors fenretinide or H 2 O 2 , recombinant caspases 3 (rC3), the caspases inhibitor DEVD-CHO, or in treatment buffer alone (control) for 0, 1, 2, 7, and 21 d at 4°C. The major immune-reactive band for desmin is indicated (Kemp & Wheeler, 2011). slaughter environment.…”

Investigation of Taste-Related Compounds and Antioxidative Profiles of Retorted Samgyetang Made from Fresh and Dried Cordyceps militaris Mushrooms

“…Meat tenderness is directly correlated with the acceptability of meat by consumers and leads to consumers’ repurchase intent ( Kemp and Wheeler, 2011 ). Tenderness is determined by complex factors, including muscle water, the degradation of muscle skeleton proteins and protease enzymes that work postmortem ( He et al, 2019 ).…”