Activation of caspase-9 and its influencing factors in beef during conditioning

Abstract

To study the activation of caspase-9 and its potential influence in conditioning, longissimus thoracis (LT), semitendinosus (STN) and psoas minor (PMi) muscles were used to analyze the ratio of pro-apoptotic bax to anti-apoptotic bcl-2 in fresh tissues and observe the changes in ATP, cytosolic cytochrome c and caspase-9 activity levels during storage at 4°C. Caspase-9 activity at 5 h is higher than the activity at 0 and 24 h in the muscles ( P < 0.001). The ATP content decreased between 0 and 3 h, between 8 and 14 h in the PMi and LT muscles ( P < 0.0001), whereas between 0 and 5 h, between 8 and 14 h in the STN muscle ( P < 0.0001). There is 60.2%, 55.3% and 43.1% available ATP in the STN, LT and PMi muscles at 5 h, respectively. The cytosolic cytochrome c level increased during 5 and 24 h storage in the LT and PMi muscles ( P < 0.0001), during 5 and 96 h in the STN muscle ( P < 0.0001). The cytosolic cytochrome c at 24 h ( P < 0.001) and ratio of bax to bcl-2 ( P < 0.05) was higher in the PMi than in other muscles. We concluded that the increase in cytosolic cytochrome c and available intracellular ATP should be responsible for the increase in caspase-9 activity; the activation of caspase-9 could be limited by the subsequent depletion of ATP; the postmortem release level of cytochrome c could be determined by the ratio of bax to bcl-2 in fresh tissues.

The changes in the proteolysis activity and the accumulation of free amino acids during chinese traditional dry-cured loins processing

“…The fragments of myofibrillar proteins in gel were identified according to the molecular weight of standard proteins. The intensities of bands were quantified by Quantity One Software (Bio-Rad Laboratories, Philadelphia, PA, USA); Electrophoresis procedures were implemented by our previous work [15]. Actin was defined as the internal standard.…”

“…The expression levels of desmin bands were assayed by SDS-PAGE and Western blotting according to our previous study [15] with slight modification. After electrophoresis, proteins were transferred to polyvinylidene fluoride membranes (Immobilon-P, Millipore, MA, USA).…”

Effects of calcium and zinc ions injection on caspase‐3 activation and tenderness in post‐mortem beef skeletal muscles

“…Cao et al . () also found the increase in cytosolic cytochrome c in PM beef skeletal muscles and believed that it was responsible the increase in caspase‐9 activity. In comparison with control, the level of cytochrome c in the Ca 2+ ‐injected samples increased markedly, as determined by Western blotting (Fig.…”

“…The rise possibly resulted from the release of cytochrome c from mitochondria to cytoplasm, which has been demonstrated by examining the cytochrome c levels in subcellular fractions of the mitochondria and cytoplasm (Huang et al, 2016). Cao et al (2014) also found the increase in cytosolic cytochrome c in PM beef skeletal muscles and believed that it was responsible the increase in caspase-9 activity. In comparison with control, the level of cytochrome c in the Ca 2+ -injected samples increased markedly, as determined by Western blotting (Fig.…”

Optimization of goose breast meat tenderness by rapid ultrasound treatment using response surface methodology and artificial neural network

“…Tenderness is one of the most important characteristics of meat quality; adequate meat tenderness has been considered as the major contributor to consumer satisfaction, and repetition for purchase of meat (Moeller et al., ; Sionek & Przybylski, ). The main factors involved in meat tenderness and postmortem changes in muscle are proteolysis, fragmentation and subsequent weakening of the myofibrillars and connective tissue (Delbarre‐Ladrat, Cheret, Taylor, & Verrez‐Bagnis, ), loss in integrity of muscle cell (Cao et al., ; Zhang et al., ; Zheng et al., ; Zhou, Wang, Pan, Sun, & Cao, ), and ultimately tenderization of meats (Lonergan, Zhang, & Lonergan, ).…”