Distribution and Degradation of Pork Filamin during Postmortem Aging

The filamin C (FLNC) was hypothesized to be colocalized with its certain binding partners in pork tissues and calpain as well as caspase was assumed responsible for the postmortem degradation of FLNC. Therefore, the specific distribution of pork FLNC and its degradation pattern during postmortem aging were investigated in this study. The longissimus thoracis muscles from 12 pigs were removed from the carcasses and then aged at 4 degrees C for 1, 6, 12, 24, 72, and 168 h, respectively. The FLNC signals appeared to localize in subsarcolemmal areas by cross-sectional images, while the localization was found surrounding the myofibrils at the level of the Z-discs in longitudinal sections. FLNC displayed a highly overlapped spatial colocalization with actin or integrin. Western blot results showed that the intact 290 kDa FLNC was rapidly degraded to produce an approximately 280 kDa band. An almost overlapped distribution pattern was observed between FLNC and mu-calpain or caspase-3 in porcine skeletal muscle cells. Moreover, both the mu-calpain inhibitor and the caspase-3 inhibitor could inhibit the degradation of FLNC in porcine LT muscles during postmortem aging.

Automated summary

This study investigated the distribution and degradation pattern of FLNC in pork during postmortem aging. The results showed that FLNC had a highly overlapped spatial colocalization with actin and integrin. FLNC was mainly localized in subsarcolemmal areas and surrounding the myofibrils at the level of the Z-discs in muscle cells. Furthermore, the study found that mu-calpain and caspase-3 were involved in the degradation of FLNC.