The importance of dietary fat components, such as fatty acids, in the expression of multiple genes is clear. In the case of beef cattle, fat in the form of fatty acids (saturated or unsaturated), vitamin A (mainly retinoic acid), or carotenoids (beta-carotene and lutein) is obtained from dietary feed or pasture. The aim of this work was to study the effect of fatty acids (phytanic and pristanic acids), vitamin A (all-trans and 9-cis retinoic acid), and carotenoids (beta-carotene and lutein) on the expression of PPARgamma and its coactivator PGC-1alpha during differentiation of bovine white adipose tissue. Samples were collected at slaughter from subcutaneous adipose tissue and processed in a solution containing type II collagenase for 2 h at 37 degrees C. Cells were resuspended in basal medium, Dulbecco's modified Eagle's medium containing 5% fetal bovine serum, plated on 24-well culture plates at a density of 1 x 10(4) cells/cm(2), and incubated at 37 degrees C in a 5% CO(2) atmosphere. Preadipocyte differentiation after reaching confluence was induced by various treatments: rosiglitazone (20 microM); unsaturated fatty acids: phytanic acid (25, 50, 100 microM) and pristanic acid (25, 50, 100 microM); retinoids: 9-cis retinoic acid (0.5, 0.75, 1 microM) and all-trans retinoic acid (0.5, 0.75, 1 microM); and carotenoids: beta-carotene (10, 20, 30 microM) and lutein (10, 20, 30 microM). Expression of PPARgamma and PGC-1alpha was measured in differentiated cells. Phytanic acid, all-trans retinoic acid, and 9-cis retinoic acid were the best activators of PPARgamma expression, and the combination of 9-cis and all-trans retinoic acid was the best activator of PGC-1alpha expression (P < 0.05). Therefore, these are powerful agents for the promotion of bovine adipogenesis and constitute promising compounds to be used in bovine fattening.

The main adipogenic transcription factor PPARγ possesses high affinity to 2,4-TZD, a member of the Thiazolidinedione family of insulin-sensitizing compounds used as adipogenic agents. We evaluated 2,4-TZD's effect on bovine growth and PPAR tissue expression. Seventeen Limousin bulls (18 month-old; 350 kg body weight (BW)) were assigned into 2 treatments: control and 2,4-TZD (8 mg/70 kg BW) and were fed until bulls reached 500 kg BW. They were weighed and their blood was sampled. DNA, RNA, and protein were determined in liver; skeletal muscle; subcutaneous (SC), omental, perirenal adipose tissues (AT) to determine protein synthesis rate and cellular size. Expression of PPAR mRNA was measured in liver and muscle (PPARα, -δ, and -γ) and SC adipose tissue (γ) by real-time PCR. No significant differences were found (P > 0.1) in weight gain, days on feed, and carcass quality. Muscle synthesis was greater in controls (P < 0.05); cell size was larger with 2,4-TZD (P < 0.05). PPARα, -δ, and -γ expressions with 2,4-TZD in liver were lower (P < 0.01) than in muscle. No differences were found for PPARγ mRNA expression in SCAT. The results suggest the potential use of 2,4-TZD in beef cattle diets, because it improves AT differentiation, liver, and muscle fatty acid oxidation that, therefore, might improve energy efficiency.

Sirtuins, the mammalian homologs of the silent information regulator 2 gene of Saccharomyces cerevisiae, are members of the NAD(+)-dependent family of histone deacetylases. In vertebrates, 7 sirtuins have been described, with different cellular localizations and target proteins. Glucose and lipid metabolism are among the processes regulated by these enzymes. In ruminants, gluconeogenesis is the main biochemical pathway by which glucose is obtained. Because sirtuins in bovines have not been studied, the aim of this work was to obtain sequences coding for the 7 sirtuins and determine the expression patterns of sirtuin1 (Sirt1) and sirtuin3 (Sirt3) in the liver, muscle, and adipose tissue of calves and bulls. Using PCR amplification, we obtained sirtuin gene sequences and reported them to the National Center for Biotechnology Information GenBank. Characteristic sequence motifs corresponding to the sirtuin catalytic core domain were found, including the active and zinc-binding sites. Relative expression patterns of Sirt1 and Sirt3 in liver, muscle, and adipose tissue were quantified by real-time PCR, normalizing to the geometric mean of the housekeeping genes cyclophilin A and β-actin. Expression of Sirt1 was less in liver and muscle, whereas it was greater in adipose tissue of adult animals, with statistical differences (P=0.0071) only in the latter. In the case of Sirt3, expression was greater in all 3 adult tissues, but statistical differences were found only in liver (P=0.0141) and muscle (P=0.0017). The greatest expression was observed in liver for Sirt1 and in muscle for Sirt3, whereas the least expression was in muscle for Sirt1 and in adipose tissue for Sirt3. In other species, sirtuin expression (both Sirt1 and Sirt3) in liver is reported to be the greatest among these 3 tissues, a pattern different from what we measured. These differences in expression can be associated with metabolic differences between nonruminant and ruminant species. However, further research on the relationship between bovine sirtuins and ruminant metabolism is required for a better understanding of these fields.

Purpose: We evaluated the effect of peroxisome proliferator-activated receptor (PPAR) agonists on the differentiation and metabolic features of bovine bone marrow-derived mesenchymal cells induced to adipogenic or myogenic lineages. Methods: Cells isolated from 7-day-old calves were cultured in basal medium (BM). For adipogenic differentiation, cells were cultured for one passage in BM and then transferred to a medium supplemented with either rosiglitazone, telmisartan, sirtinol or conjugated c-9, t-11 linoleic acid; for myogenic differentiation, third-passage cells were added with either bezafibrate, telmisartan or sirtinol. The expression of PPARγ (an adipogenic differentiation marker), myosin heavy chain (MyHC; a myogenic differentiation marker) and genes related to energy metabolism were measured by quantitative real-time PCR in a completely randomized design. Results: For adipogenic differentiation, 20 µM telmisartan showed the highest PPARγ expression (15.58 ± 0.62-fold, p < 0.0001), and differences in the expression of energy metabolism-related genes were found for hexokinase II, phosphofructokinase, adipose triglyceride lipase, acetyl-CoA carboxylase α(ACACα) and fatty acid synthase (p < 0.001), but not for ACACβ (p = 0.4275). For myogenic differentiation, 200 µM bezafibrate showed the highest MyHC expression (73.98 ± 11.79-fold), and differences in the expression of all energy metabolism-related genes were found (p < 0.05). Conclusions: Adipocyte and myocyte differentiation are enhanced with telmisartan and bezafibrate, respectively, and energy uptake, storage and mobilization are improved with both.

Purpose: The aim of this work was to evaluate the effect of PPAR agonists on the differentiation and metabolic features of porcine mesenchymal stem cells induced to the adipogenic or myogenic lineages. Methods: Bone marrow MSCs from neonate pigs were isolated and identified by cell proliferation, cell surface markers or the gene expression of stem cells (CD44, CD90, CD105 or Oct4 and Nanog, respectively). Cells were differentiated into adipose or muscle cells and treated with the PPAR agonists; adipogenic and myogenic differentiation was promoted by adding these compounds. The expression of PPARγ (an adipose marker) and MyoD1 and MyHC (muscle markers), metabolic changes and expression levels of metabolic enzymes involved in glycolysis, lipogenesis, lipolysis and the pentose phosphate pathway were tested by qPCR. Results: MSCs from neonate pigs exhibited high proliferation and were positive for CD44, CD90 and CD105 markers and Oct4 and Nanog expression. The treatment that promoted the highest expression of PPARγ was 50 µM of conjugated linoleic acid (CLA) c9 t11 (6.44 ± 0.69-fold, p ≤ 0.0001) in the adipose differentiation, and upregulation of HX2, ACCAα, ATGL, LPL and G6DP (p ≤ 0.0001) and downregulation of PFK and ACCAβ (p ≤ 0.0001) were found. For muscle differentiation, the best treatment was 50 µM of CLA c10 t12 (59.72 ± 4.72-fold, p ≤ 0.0001), and metabolic changes were upregulation of PFK, ACCAβ, G6DP, CPT1 and PPARβ/δ (p ≤ 0.0001), but no effect was observed with HX2 and ACCAα (p ≥ 0.05). Conclusions: Our results suggest that differentiated cells exhibit a typical cell lineage metabolism and higher efficiencies both in anabolism and catabolism.

Pasture-fed cattle yield carcasses with yellow fat; consumers often reject the resulting meat products because they assume they come from old and/or culled animals. Recombinant bacteria expressing beta-carotene 15, 15'-monooxygenase, introduced into the rumen of the animal, might help to reduce the coloration since this enzyme converts carotene to retinal, thereby eliminating the source of yellowness. The goal of this work was to evaluate the effect of a recombinant beta-carotene 15, 15'-monooxygenase (BCMO1) from Gallus gallus, expressed in Escherichia coli. The genetically modified microbe was introduced into ruminal fluid, and carotene conversion to retinal was measured. Under optimum conditions the enzyme produced 6.8 nmol of retinal per 1 mg of protein in 1 hour at 37 °C. The data on in vitro digestibility in ruminal fluid showed no differences in beta-carotene breakdown or in retinal production (p > 0.1) between E. coli with pBAD vector alone and E. coli with pBAD/BCMO1. The pBAD/BCMO1 plasmid was stable in E. coli for 750 generations. These results indicate that the protein did not break beta-carotene into retinal in ruminal fluid, perhaps due to its location in the periplasmic space in E. coli. Future research must consider strategies to release the enzyme into the rumen environment.

The expression and digestive activity of pike silverside Chirostoma estor endogenous chitinases were analysed in samples from four life stages: whole eggs; larvae; juvenile intestine and hepatopancreas and adult intestine and hepatopancreas. A chitinase cDNA was cloned and partially sequenced (GenBank accession number: FJ785521). It was highly homologous to non-acidic chitinase sequences from other fish species, suggesting that it is a chitotriosidase. Quantitative PCR showed that this chitinase was expressed throughout the life span of C. estor, with maximum expression in the hepatopancreas of juveniles. Chitotriosidase and chitobiosidase activities were found at all life stages, along with a very high level of N-acetyl glucosaminidase (NAGase). The chitotriosidase activity could be encoded by the cloned complementary (c)DNA, although additional chitinase genes may be present. The chitotriosidase activity appeared to be transcriptionally regulated only at the juvenile stage. The expression and activity of chitinases tended to increase from the early to juvenile stages, suggesting that these variables are stimulated by chitin-rich live food. Nevertheless, the feeding of juvenile and adult fish with both live food and a balanced commercial diet seemed to provoke significant reductions in pancreatic NAGase secretion and/or synthesis in the gut. Moreover, all chitinase activities were lower in adults, probably reflecting a higher intake and use of the balanced diet. The observation of chitotriosidase and chitobiosidase activities together with a very high NAGase activity suggest the presence of a complete and compensatory chitinolytic chitinase system that enables this stomachless short-gut fish species to use chitin as an energy substrate. These novel findings suggest that dietary inclusions of chitin-rich ingredients or by-products might reduce the farming costs of C. estor without impairing performance.

This study aims to evaluate the effect of H. perforatum and S. cordifolia extracts on hepatic steatosis in obese rats, and to elucidate their mechanisms through a lipidomic analysis. Fifty‐seven phytochemical compounds are identified in H. perforatum and S. cordifolia aqueous extracts by UPLC‐QTOF MSE. Both herbal aqueous extracts ameliorate hepatic steatosis. S. cordifolia modulates arachidonic acid, 16:0‐, 16:1‐, and 18:0‐derived TAG, ceramides, and diacylglycerols, regulating the expression of genes involved in fatty acid (Fas, Acc, and Scd1), diacylglyceride (Gpat) and ceramide (Spt1) biosynthesis, and β‐oxidation (Cpt1 and Acadm). H. perforatum regulates eicosapentanoic acid metabolism, which is associated with Fabp down‐regulation. Both extracts reduce hepatic TNF‐α and IL‐6 levels, which is associated with eicosanoid pathway regulation by S. cordifolia and the modulation of phosphatidylcholines and phosphatidylethanolamines by H. perforatum. These results suggest that these aqueous extracts can be used as ingredients for the elaboration of functional beverages with hepatoprotective effects. Practical Applications: This study proposes a lipidomic approach followed by the integration of metabolic networks for the identification of the mechanisms associated with the hepatoprotective effect of herbal extracts. The results obtained in this study demonstrate the beneficial effect of S. cordifolia and H. perforatum aqueous extracts on hepatic steatosis in high‐fat and fructose diet‐fed obese rats. Therefore, these herbs can be used for the elaboration of functional beverages. H. perforatum and S. cordifolia aqueous extracts ameliorate hepatic steatosis in obese rats. A liver lipidome approach is used to identify the mechanisms associated with their hepatoprotective effect by integrating metabolic networks. H. perforatum decreases Fabp hepatic expression which is associated mainly with decreased hepatic EPA. S. cordifolia decreased Fasn, Acaca, Scd1, Gpat1, and Spt1 and increased Cpt1 and Acadm hepatic expressiobm which is associated mainly with increased AA. These herbs have potential for the development of functional beverages or dietary supplements with hepatoprotective effects.