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Molecular Factors Underlying the Deposition of Intramuscular Fat and Collagen in Skeletal Muscle of Nellore and Angus Cattle.

Martins TS, Sanglard LM, Silva W, Chizzotti ML, Rennó LN, Serão NV, Silva FF, Guimarães SE, Ladeira MM, Dodson MV, Du M, Duarte MS - PLoS ONE (2015)

Bottom Line: A greater intramuscular fat content was observed in skeletal muscle of Angus compared to Nellore cattle (P≤0.05).Similarly, no differences were observed in mRNA expression of adipogenic markers Zfp423, PPARγ, and C/EBPα (P>0.05) However, a greater PPARγ protein content was observed in skeletal muscle of Angus compared to Nellore cattle (P≤0.05).These findings demonstrate that difference in intramuscular fat content is associated with a slightly enhanced adipogenesis in skeletal muscle of Angus compared to Nellore cattle, while no difference in fibrogenesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Animal Science, Universidade Federal de Viçosa, Viçosa, Brazil.

ABSTRACT
Studies have shown that intramuscular adipogenesis and fibrogenesis may concomitantly occur in skeletal muscle of beef cattle. Thus, we hypothesized that the discrepancy of intramuscular fat content in beef from Nellore and Angus was associated with differences in intramuscular adipogenesis and fibrogenesis during the finishing phase. To test our hypothesis, longissimus muscle samples of Nellore (n = 6; BW = 372.5 ± 37.3 kg) and Angus (n = 6; BW = 382.8 ± 23.9 kg) cattle were collected for analysis of gene and protein expression, and quantification of intramuscular fat and collagen. Least-squares means were estimated for the effect of Breed and differences were considered at P ≤ 0.05. A greater intramuscular fat content was observed in skeletal muscle of Angus compared to Nellore cattle (P≤0.05). No differences were observed for mRNA expression of lipogenic and lipolytic markers ACC, FAS, FABP4, SERBP-1, CPT-2, LPL, and ACOX (P > 0.05) in skeletal muscle of Nellore and Angus cattle. Similarly, no differences were observed in mRNA expression of adipogenic markers Zfp423, PPARγ, and C/EBPα (P>0.05) However, a greater PPARγ protein content was observed in skeletal muscle of Angus compared to Nellore cattle (P≤0.05). A greater abundance of adipo/fibrogenic cells, evaluated by the PDGFRα content, was observed in skeletal muscle of Angus than Nellore cattle (P≤0.05). No differences in fibrogenesis were observed in skeletal muscle of Angus and Nellore cattle, which is in accordance with the lack of differences in intramuscular collagen content in beef from both breeds (P>0.05). These findings demonstrate that difference in intramuscular fat content is associated with a slightly enhanced adipogenesis in skeletal muscle of Angus compared to Nellore cattle, while no difference in fibrogenesis.

No MeSH data available.


Collagen content, expression of fibrogenic and collagen remodeling markers in skeletal muscle of Angus and Nellore cattle.Intramuscular collagen content based on hydroxyproline concentration; B) mRNA expression of transform growth factor beta (TGF-β), collagen I (COL1A1), collagen III (COL3A3), and fibronectin; C) TGF-β abundance evaluated by western-blot; D) mRNA expression of lysyl oxidase (LOX), metalloproteinase II (MMP2) and tissue inhibitor of metalloproteinase 1 (TIMP1); Tubulin was used as a loading control. Differences were considered at P ≤ 0.05 (*).
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pone.0139943.g003: Collagen content, expression of fibrogenic and collagen remodeling markers in skeletal muscle of Angus and Nellore cattle.Intramuscular collagen content based on hydroxyproline concentration; B) mRNA expression of transform growth factor beta (TGF-β), collagen I (COL1A1), collagen III (COL3A3), and fibronectin; C) TGF-β abundance evaluated by western-blot; D) mRNA expression of lysyl oxidase (LOX), metalloproteinase II (MMP2) and tissue inhibitor of metalloproteinase 1 (TIMP1); Tubulin was used as a loading control. Differences were considered at P ≤ 0.05 (*).

Mentions: A similar content of total intramuscular collagen was observed in skeletal muscle of Angus and Nellore cattle (P = 0.16; Fig 3A). Indeed, no differences were observed for mRNA expression of fibrogenic markers TGF-β (P = 0.24), collagen I (P = 0.30), fibronectin (P = 0.32), and collagen III (P = 0.07) in skeletal muscle of Angus compared to Nellore cattle (Fig 3B).


Molecular Factors Underlying the Deposition of Intramuscular Fat and Collagen in Skeletal Muscle of Nellore and Angus Cattle.

Martins TS, Sanglard LM, Silva W, Chizzotti ML, Rennó LN, Serão NV, Silva FF, Guimarães SE, Ladeira MM, Dodson MV, Du M, Duarte MS - PLoS ONE (2015)

Collagen content, expression of fibrogenic and collagen remodeling markers in skeletal muscle of Angus and Nellore cattle.Intramuscular collagen content based on hydroxyproline concentration; B) mRNA expression of transform growth factor beta (TGF-β), collagen I (COL1A1), collagen III (COL3A3), and fibronectin; C) TGF-β abundance evaluated by western-blot; D) mRNA expression of lysyl oxidase (LOX), metalloproteinase II (MMP2) and tissue inhibitor of metalloproteinase 1 (TIMP1); Tubulin was used as a loading control. Differences were considered at P ≤ 0.05 (*).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4593631&req=5

pone.0139943.g003: Collagen content, expression of fibrogenic and collagen remodeling markers in skeletal muscle of Angus and Nellore cattle.Intramuscular collagen content based on hydroxyproline concentration; B) mRNA expression of transform growth factor beta (TGF-β), collagen I (COL1A1), collagen III (COL3A3), and fibronectin; C) TGF-β abundance evaluated by western-blot; D) mRNA expression of lysyl oxidase (LOX), metalloproteinase II (MMP2) and tissue inhibitor of metalloproteinase 1 (TIMP1); Tubulin was used as a loading control. Differences were considered at P ≤ 0.05 (*).
Mentions: A similar content of total intramuscular collagen was observed in skeletal muscle of Angus and Nellore cattle (P = 0.16; Fig 3A). Indeed, no differences were observed for mRNA expression of fibrogenic markers TGF-β (P = 0.24), collagen I (P = 0.30), fibronectin (P = 0.32), and collagen III (P = 0.07) in skeletal muscle of Angus compared to Nellore cattle (Fig 3B).

Bottom Line: A greater intramuscular fat content was observed in skeletal muscle of Angus compared to Nellore cattle (P≤0.05).Similarly, no differences were observed in mRNA expression of adipogenic markers Zfp423, PPARγ, and C/EBPα (P>0.05) However, a greater PPARγ protein content was observed in skeletal muscle of Angus compared to Nellore cattle (P≤0.05).These findings demonstrate that difference in intramuscular fat content is associated with a slightly enhanced adipogenesis in skeletal muscle of Angus compared to Nellore cattle, while no difference in fibrogenesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Animal Science, Universidade Federal de Viçosa, Viçosa, Brazil.

ABSTRACT
Studies have shown that intramuscular adipogenesis and fibrogenesis may concomitantly occur in skeletal muscle of beef cattle. Thus, we hypothesized that the discrepancy of intramuscular fat content in beef from Nellore and Angus was associated with differences in intramuscular adipogenesis and fibrogenesis during the finishing phase. To test our hypothesis, longissimus muscle samples of Nellore (n = 6; BW = 372.5 ± 37.3 kg) and Angus (n = 6; BW = 382.8 ± 23.9 kg) cattle were collected for analysis of gene and protein expression, and quantification of intramuscular fat and collagen. Least-squares means were estimated for the effect of Breed and differences were considered at P ≤ 0.05. A greater intramuscular fat content was observed in skeletal muscle of Angus compared to Nellore cattle (P≤0.05). No differences were observed for mRNA expression of lipogenic and lipolytic markers ACC, FAS, FABP4, SERBP-1, CPT-2, LPL, and ACOX (P > 0.05) in skeletal muscle of Nellore and Angus cattle. Similarly, no differences were observed in mRNA expression of adipogenic markers Zfp423, PPARγ, and C/EBPα (P>0.05) However, a greater PPARγ protein content was observed in skeletal muscle of Angus compared to Nellore cattle (P≤0.05). A greater abundance of adipo/fibrogenic cells, evaluated by the PDGFRα content, was observed in skeletal muscle of Angus than Nellore cattle (P≤0.05). No differences in fibrogenesis were observed in skeletal muscle of Angus and Nellore cattle, which is in accordance with the lack of differences in intramuscular collagen content in beef from both breeds (P>0.05). These findings demonstrate that difference in intramuscular fat content is associated with a slightly enhanced adipogenesis in skeletal muscle of Angus compared to Nellore cattle, while no difference in fibrogenesis.

No MeSH data available.