Oleic acid in the absence of a PPARγ agonist increases adipogenic gene expression in bovine muscle satellite cells1

Abstract

We hypothesized that oleic acid (OA) in the absence of a thiazolidinedione (i.e., a synthetic peroxisome proliferator-activated receptorγ [PPARγ] agonist) would increase adipogenic gene expression in bovine muscle satellite cells (BSC). The BSC were cultured in differentiation medium containing 10 µM ciglitazone (CI), 100 µM OA, or 100 µM OA plus 10 µM CI (CI-OA). Control (CON) BSC were cultured only in differentiation media (containing 2% horse serum). The presence of myogenin, desmin, and paired box 7 proteins was confirmed in the BSC by immunofluorescence staining, demonstrating that we had isolated myogenic cells. The OA BSC had lesser paired box 3 (Pax3) and myogenic differentiation 1 expression but greater Pax7 and mygogenin (MYOG) expression (P < 0.05), than the CON BSC. The CI BSC had greater Pax3, Pax7, and MYOG expression than CON BSC (P < 0.05), suggesting that CI would promote BSC myogenesis under pro-myogenic conditions (i.e., when cultured with horse serum). However, both the OA and CI treatments upregulated the expression of PPARγ, CCAAT/enhancer-binding protein alpha (C/EBPα) and C/EBPß, sterol regulatory element-binding protein 1, lipoprotein lipase, and glycerol-3-phosphate acyltransferase 3 gene expression, as well as media adiponectin concentration (P < 0.05). The CI, OA, and CI-OA treatments also increased triacylglycerol and lipid droplet accumulation, in spite of upregulation (relative to CON BSC) of adenosine monophosphate-activated protein kinase alpha-1, perilipin 2 (PLIN2), and PLIN3 in BSC and downregulation of G protein-coupled protein receptor 43, acyl-CoA synthetase long chain family member 3, and stearoyl-CoA desaturase (P < 0.05). These results indicate that OA in the absence of a synthetic PPARγ agonist can effectively increase adipogenic gene expression in BSC.

Ciglitazone Increases Adiponectin and Adipogenic Gene Expression in Bovine Skeletal Muscle Satellite Cells

“…In this study, ciglitazone in the absence of an adipocyte differentiation cocktail also induced an up-regulation of adipogenic gene expression accompanied by low expression of MYOD. And the higher PLIN2 expression and adiponectin promotes the higher lipid droplets accumulation in the BSC [4]. The PI3K-Akt signaling pathway plays an important regulatory role in adipocyte differentiation and adipogenesis.…”

“…Teboul et al first reported the almost complete conversion of C2C12 myoblasts to lipid-filled cells when incubated with linoleic acid (18:2n-6) plus the TZD pioglitazone, as indicated by a cessation of myoblast fusion, swelling of myoblasts through lipid filling, down-regulation of myogenin (MYOG), and up-regulation of adipocyte lipid-binding protein gene expression [5]. In our previous study [4], we established that 10 µM ciglitizone down-regulated the expression of genes associated with myogenesis, and up-regulated genes involved in adipogenesis. However, we did not establish that 10 µM ciglitizone would elicit maximal effects on adipogenesis and/or myogenesis.…”

“…Singh et al reported that the TZD ciglitazone up-regulated PPARγ and C/EBPα gene expression and depressed myoblast fusion in porcine satellite cells [3]. Our laboratory previously reported that culture of bovine muscle satellite cells (BSC) in medium supplemented with oleic acid (18:1n-9), in the absence or presence of ciglitazone, responded with increases in PPARγ and CCAAT/enhancer-binding protein beta (C/EBPß) gene expression in myotubes [4]. Teboul et al first reported the almost complete conversion of C2C12 myoblasts to lipid-filled cells when incubated with linoleic acid (18:2n-6) plus the TZD pioglitazone, as indicated by a cessation of myoblast fusion, swelling of myoblasts through lipid filling, down-regulation of myogenin (MYOG), and up-regulation of adipocyte lipid-binding protein gene expression [5].…”

Simple and effective serum-free medium for sustained expansion of bovine satellite cells for cell cultured meat

“…Computational approaches to media development are better suited for solving such multifactorial problems, and should therefore be leveraged to further optimize Beefy-9 and other serum-free media for cultured meat applications 27 . Here, efforts can focus on adipose as well as muscle tissue, for instance through the use of free fatty acid addition to Beefy-9 to induce the transdifferentiation of BSCs into lipid-accumulating cells 31 . Additionally, further work is needed to overcome the slower long-term growth and aberrant lipid accumulation that is seen in BSCs cultured over seven passages in Beefy-9.…”

Effect of palmitoleic acid on the differentiation of bovine skeletal muscle satellite cells

“…Earlier studies have shown that cells from myogenic cultures that have showed myogenic response could be transferred from this pathway when treated with bone-morphogenetic proteins or adipogenic-inducing agents (12,13). Our previous studies have shown that oleic acid, as the most abundant monounsaturated fatty acid in beef marbling, has the ability to differentiate microsatellite cells into adipocyte-like lipid droplets (14). However, it is not clear whether palmitoleic acid (POA), the second most abundant monounsaturated fatty acid in beef marbling, has the same characteristics as oleic acid.…”