Changes in proteolytic enzymes mRNAs and proteins relevant for meat quality during myogenesis and hypoxia of primary bovine satellite cells.
The current study was conducted to evaluate the functions of μ-calpain (CAPN1), calpastatin, HSPs (heat shock proteins), and caspases during myogenesis and cell death induced by sodium azide (NaN(3)) hypoxia. The cell samples were divided into three groups: satellite cells formed at confluent monolayer (stage 1), stage 1 cells fusion into myotubes on d eight post-differentiation (stage 2), and stage 2 cells treated with 1 mM NaN(3) for 24 h (stage 3). Real-time RT-PCR showed that stage 2 cells had increased CAPN1, calpastatin, caspase 7, and CARD9 (Caspase activation and recruitment domain 9) mRNA expressions compared to stage 1 cells (*p < 0.05). By Western blotting caspase 3, caspase 7, caspase 8, and caspase 9 protein levels increased in cells at stage 2 compared to cells at stage 1 (*p < 0.05). Real-time RT-PCR showed that stage 3 cells had increased CAPN1, calpastatin, caspase 7, HSP70 (70 kDA heat shock proteins), and HSP90 (90 kDA heat shock proteins-alpha) and decreased CARD9 mRNA expression compared to stage 2 cells (*p < 0.05). Stage 3 samples had increase caspase 7 and caspase 12 activities compared to stage 2 samples, and by Western blotting protein levels of both HSP70 and HSP90 expressions, increased significantly under hypoxia condition (*p < 0.05). Here, we conclude that CAPN1, calpastatin, caspase 3, caspase 7, caspase 8, and CARD9 have important roles for satellite cell myogenesis; and that caspase 7, 12, HSP70, and HSP90 are involved in the process of apoptotic cell death under hypoxia conditions and we speculate that these proteins may be involved in early postmortem proteolysis and meat tenderization.
Department of Animal Science and Institute of Rare Earth for Biological Aplication, Chonbuk National University, Deokjin-gu, Jeonju-si, Jeollabuk-do, Republic of Korea.
You Bing
YB
Yang
Muthuraman
M
Pandurangan
InHo
I
Hwang
D000818:Animals; D017209:Apoptosis; D053468:CARD Signaling Adaptor Proteins / Q000235:genetics / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D002154:Calpain / Q000235:genetics* / Q000378:metabolism; D020169:Caspases / Q000235:genetics / Q000378:metabolism; D002417:Cattle; D015687:Cell Hypoxia; D002478:Cells, Cultured; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D008460:Meat; D024510:Muscle Development; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D059748:Proteolysis; D012333:RNA, Messenger / Q000378:metabolism; D032496:Satellite Cells, Skeletal Muscle / Q000378:metabolism*; D019810:Sodium Azide
D053468:CARD Signaling Adaptor Proteins; D002135:Calcium-Binding Proteins; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D012333:RNA, Messenger; C033668:calpastatin; D019810:Sodium Azide; D002154:Calpain; D020169:Caspases; C449002:mu-calpain