title: Activation of caspase-3 and its correlation with shear force in bovine skeletal muscles during postmortem conditioning.
abstract: The study was aimed at exploring the mechanism of tenderization by establishing a correlation between caspase-3 activity and shear force, verifying the activation occurring by analyzing active caspase-3 and cleaved poly (ADP-ribose) polymerase (PARP) fragments, and understanding the pathways involved in activation of caspase-3 by evaluating its correlation with caspase-8 and -9 activities in LM, semitendinosus (STN), and psoas minor (PM) muscles. The results indicated that shear force decreased at 48 h in PM (P < 0.01), LM (P < 0.01), and STN (P < 0.05). We detected p22, p23, p20, and p18 caspase fragments as well as distinctive PARP fragments of 24 kDa by caspase-3 and 36 kDa by µ-calpain. Caspase-3 activity correlated with shear force negatively at 24 and 48 h in STN (P < 0.01 at 24 h; P < 0.01 at 48 h), PM (P < 0.001 at 24 h; P < 0.01 at 48 h), and LM muscles (P < 0.05 at 24 h; P < 0.01 at 48 h). The greatest activities of caspase-8 (P < 0.001 in PM and STN; P < 0.01 in LM) and caspase-9 (P < 0.001 in muscles) appeared at 4 h whereas that of caspase-3 was at 24 h (P < 0.001 in muscles). Caspase-9 activity correlated positively with caspase-3 at 4, 24, and 48 h in STN (P < 0.01 at 4 h; P < 0.05 at 24 h; P < 0.001 at 48 h) and at 4 and 96 h in PM (P < 0.001 at 4 h; P < 0.05 at 96 h) and LM muscles (P < 0.001 at 4 h; P < 0.001 at 96 h). The caspase-8 activity correlated with caspase-3 at 4, 48, and 96 h in STN (P < 0.05 at 4 h; P < 0.001 at 48 h; P < 0.05 at 96 h), at 4 and 24 h in PM (P < 0.001 at 4 h; P < 0.05 at 24 h), and at 4 and 96 h in LM (P < 0.001 at 4 h; P < 0.01 at 96 h). We concluded that caspase-3 was associated with the decline of shear force; the activation of caspase-3 was mediated by caspases -8 and -9 in muscles. However, more detailed studies are needed to define the precise mechanism for the cleavage of pro-caspases -8 and -9 during conditioning.
authors.affiliation: College of Life Science and Biotechnology, Ningbo University, Ningbo 315211, PR China.
authors.forename: J-X
authors.initials: JX
authors.lastname: Cao
authors.forename: C-R
authors.initials: CR
authors.lastname: Ou
authors.forename: Y-F
authors.initials: YF
authors.lastname: Zou
authors.forename: K-P
authors.initials: KP
authors.lastname: Ye
authors.forename: Q-Q
authors.initials: QQ
authors.lastname: Zhang
authors.forename: M A
authors.initials: MA
authors.lastname: Khan
authors.forename: D-D
authors.initials: DD
authors.lastname: Pan
authors.forename: G
authors.initials: G
authors.lastname: Zhou
mesh_terms: D000818:Animals; D015153:Blotting, Western / Q000662:veterinary; D053148:Caspase 3 / Q000378:metabolism*; D053181:Caspase 8 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D020169:Caspases / Q000378:metabolism*; D002417:Cattle; D008297:Male; D008460:Meat / Q000032:analysis*; D018482:Muscle, Skeletal / Q000378:metabolism*; D011180:Postmortem Changes; D013314:Stress, Mechanical
chemical_list: D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases