Glycerol-3-phosphate Dehydrogenase Activity Research Articles

Multiomics Studies on Metabolism Changes in Alcohol-Associated Liver Disease.

Metabolic dysfunction in the liver represents a predominant feature in the early stages of alcohol-associated liver disease (ALD). However, the mechanisms underlying this are only partially understood. To investigate the metabolic characteristics of the liver in ALD, we did a relative quantification of polar metabolites and lipids in the liver of mice with experimental ALD using untargeted metabolomics and untargeted lipidomics. A total of 99 polar metabolites had significant abundance alterations in the livers of alcohol-fed mice. Pathway analysis revealed that amino acid metabolism was the most affected by alcohol in the mouse liver. Metabolites involved in glycolysis and the TCA cycle were decreased, while glycerol 3-phosphate (G3P) and long-chain fatty acids were increased. Relative quantification of lipids unveiled an upregulation of multiple lipid classes, suggesting that alcohol consumption drives metabolism toward lipid synthesis. Results from enzyme expression and activity detection indicated that the decreased activity of mitochondrial glycerol 3-phosphate dehydrogenase contributed to the disordered metabolism.

Effect of 4 hydroxy fatty acids on lipid accumulation in the 3T3-L1 cells: a comparative study.

Notwithstanding the several investigations of the hydroxy fatty acids (hFAs)' physiological functions, studies focusing on their anti-obesity effects are limited. This study investigated the anti-obesity effects of 4 hFAs-10-hydroxy stearic acid (10-hSA), 12-hydroxy stearic acid (12-hSA), 9,12-hydroxy stearic acid (9,12-dhSA), and 12-hydroxy oleic acid (12-hOA)-on the 3T3-L1 cells. All hFAs suppressed lipid accumulation, with 10-hSA and 12-hOA exhibiting the strongest suppression, followed by 12-hSA and 9,12-hSA. This trend was similar to that observed for the glycerol-3-phosphate dehydrogenase (GPDH) activity level. Contrastingly, only 9,12-dhSA suppressed cell viability. The mRNA levels of HK1 and Aldoa were markedly suppressed by 10-hSA and 12-hSA compared to the control. Additionally, mRNA expression of Gyk was considerably suppressed by 12-hSA. Thus, all hFAs suppressed lipid accumulation by suppressing GPDH activity, although their molecular mechanisms were different. These findings will aid the application of hFAs in the food and medical industries.

Quercetin inhibits body weight gain and adipogenesis via matrix metalloproteinases in mice fed a high-fat diet.

Limited studies reported that quercetin inhibited adipogenesis and neovascularization by inhibiting matrix metalloproteinases (MMPs) activity, but such mechanisms have not been elucidated in animal experiments. In this study, we investigated the inhibitory effects of quercetin on weight gain and adipose tissue growth through the regulation of mRNA expressions of adipogenic transcription factors and MMPs in mice fed a high-fat diet (HFD). Five-wk-old C57BL/6J mice were fed a normal diet (ND), HFD, HFD containing 0.05% of quercetin (HFQ0.05), or HFD containing 0.15% of quercetin (HFQ0.15) for 16 wks. Glycerol-3-phosphate dehydrogenase (GPDH) activity was measured using a commercial kit. The mRNA expressions of transcription factors related to adipocyte differentiation were determined by real-time polymerase chain reaction (PCR). The mRNA expressions of MMPs and concentrations of MMPs were measured by real-time PCR and enzyme-linked immunosorbent assay kit, respectively. Quercetin intake reduced body weight gain and epididymal adipose tissue weights (P < 0.05). GPDH activity was higher in the HFD group than in the ND group but lower in the quercetin groups (P < 0.05). The mRNA expressions of CCAAT/enhancer binding protein β (C/EBPβ), C/EBPα, peroxisome proliferator-activated receptor γ, and fatty acid-binding protein 4 were lower in the quercetin groups than in the HFD group (P < 0.05). Similarly, the mRNA expression and concentrations of MMP-2 and MMP-9 were significantly lower in the quercetin groups than in the HFD group (P < 0.05). The study confirms that quercetin suppresses body weight gain and adipogenesis by inhibiting transcription factors related to adipocyte differentiation and MMPs (MMP-2 and MMP-9), in mice fed a HFD.

Riboflavin salvage by Borrelia burgdorferi supports carbon metabolism and is essential for survival in the tick vector.

The Lyme disease agent, Borrelia burgdorferi, harbors a significantly reduced genome and relies on the scavenging of critical nutrients from its tick and mammalian hosts for survival. Riboflavin salvage has been shown to be important for B. burgdorferi infection of mice, yet the contributions of riboflavin to B. burgdorferi metabolism and survival in the tick remain unknown. Using a targeted mass spectrometry approach, we confirmed the importance of bb0318, the putative ATPase component of an ABC-type riboflavin transporter, for riboflavin salvage and the production of FMN and FAD. This analysis further revealed that Δbb0318 B. burgdorferi displayed increased levels of glycerol 3-phosphate compared to the wild-type. The glycerol 3-phosphate dehydrogenase activity of GlpD was found to be FAD-dependent and the transcription and translation of glpD were significantly decreased in Δbb0318 B. burgdorferi. Finally, gene bb0318 was found to be important for maximal spirochete burden in unfed larvae and essential for survival in feeding ticks. Together, these data demonstrate the importance of riboflavin salvage for B. burgdorferi carbon metabolism and survival in ticks.

Myostatin suppresses adipogenic differentiation and lipid accumulation by activating crosstalk between ERK1/2 and PKA signaling pathways in porcine subcutaneous preadipocytes.

The current study was undertaken to determine the effect of myostatin (MSTN) on lipid accumulation in porcine subcutaneous preadipocytes (PSPAs) and to further explore the potential molecular mechanisms. PSPAs isolated from Meishan weaned piglets were added with various concentrations of MSTN recombinant protein during the entire period of adipogenic differentiation process. Results showed that MSTN treatment significantly reduced the lipid accumulation, intracellular triglyceride (TG) content, glucose consumption, and glycerol phosphate dehydrogenase activity, while increased glycerol and free fatty acid release. Consistent with above results, the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway was obviously activated and thus key adipogenic transcription factors peroxisome proliferator-activated receptor-gamma (PPAR-γ), CCAAT/enhancer-binding protein-alpha (C/EBP-α), and their downstream enzymes fatty acid synthase and acetyl-CoA carboxylase were all inhibited. However, chemical inhibition of ERK1/2 signaling pathway by PD98059 markedly reversed the decreased TG content by increasing PPAR-γ expression. In addition, MSTN activated the cyclic AMP/protein kinase A (cAMP/PKA) pathway and stimulated lipolysis by reducing the expression of antilipolytic gene perilipin, thus elevated key lipolytic enzymes adipose triglyceride lipase and hormone-sensitive lipase (HSL) expression and enzyme activity. On the contrary, pretreatment with PKA inhibitor H89 significantly reversed TG accumulation by increasing PPAR-γ expression and thus inhibiting ERK1/2, perilipin, and HSL phosphorylation, supporting the crosstalk between PKA and ERK1/2 pathways in both the anti-adipogenic and pro-lipolytic effects. In summary, our results suggested that MSTN suppressed adipogenesis and stimulated lipolysis, which was mainly mediated by activating crosstalk of ERK1/2 and PKA signaling pathways, and consequently decreased lipid accumulation in PSPAs, our findings may provide novel insights for further exploring MSTN as a potent inhibitor of porcine subcutaneous lipid accumulation.

Effect of Sake Lees on the Inhibition of Lipid Accumulation in Adipocytes

Recent lifestyle changes, such as the Westernization of diets and the rise in the prevalence of obesity, with an associated increase in the number of patients with lifestyle-related diseases, have become a social issue. Fermented food has attracted attention as a solution to problems caused by obesity. Sake lees, a byproduct of sake brewing, represent one such food that is expected to have health benefits. In this study, we investigated the effects of sake lees components on preadipocytes (3T3-L1). We cultured preadipocytes in a medium with indigestible sake lees components (ISLCs) to investigate lipid accumulation, analyzed the glycerol 3-phosphate dehydrogenase (GPDH) and LPL activities of those cells, and performed a real-time PCR analysis of the IL6 expression in the cells. The results show that lipid accumulation and GPDH activity were significantly decreased in adipocytes treated with 1.0 mg/mL ISLCs compared to untreated cells. Furthermore, the expression of IL6 in adipocytes treated with 1.0 mg/mL ISLCs was significantly decreased and the lipase activity was significantly increased in adipocytes treated with ISLCs after differentiation. IL6 is known to have multiple functions in adipose tissue. In conclusion, ISLCs were associated with reduced lipid accumulation in adipocytes, with effects on IL6 expression and LPL activity observed throughout the differentiation period.

The Combined Influence of Magnesium and Insulin on Central Metabolic Functions and Expression of Genes Involved in Magnesium Homeostasis of Cultured Bovine Adipocytes.

At the onset of lactation, dairy cows suffer from insulin resistance, insulin deficiency or both, similar to human diabetes, resulting in lipolysis, ketosis and fatty liver. This work explored the combined effects of different levels of magnesium (0.1, 0.3, 1 and 3 mM) and insulin (25, 250 and 25,000 pM) on metabolic pathways and the expression of magnesium-responsive genes in a bovine adipocyte model. Magnesium starvation (0.1 mM) and low insulin (25 pM) independently decreased or tended to decrease the accumulation of non-polar lipids and uptake of the glucose analog 6-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-6-deoxyglucose (6-NBDG). Activity of glycerol 3-phosphate dehydrogenase (GPDH) was highest at 25 pM insulin and 3 mM magnesium. Expression of SLC41A1 and SLC41A3 was reduced at 0.1 mM magnesium either across insulin concentrations (SLC41A1) or at 250 pM insulin (SLC41A3). MAGT1 expression was reduced at 3 mM magnesium. NIPA1 expression was reduced at 3 mM and 0.1 mM magnesium at 25 and 250 pM insulin, respectively. Expression of SLC41A2, CNNM2, TRPM6 and TRPM7 was not affected. We conclude that magnesium promotes lipogenesis in adipocytes and inversely regulates the transcription of genes that increase vs. decrease cytosolic magnesium concentration. The induction of GAPDH activity by surplus magnesium at low insulin concentration can counteract excessive lipomobilization.

Pomolic acid in persimmon peel suppresses the increase in glycerol-3 phosphate dehydrogenase activity in 3T3-L1 adipocytes.

Persimmon peels, though usually discarded, are useful sources of nutraceuticals. In this study, persimmon peel-derived pomolic acid was found to suppress the increase in the activity of glycerol-3 phosphate dehydrogenase, a neutral fat synthesis-related enzyme, in 3T3-L1 adipocytes, whereas oleanolic and ursolic acids did not exert this effect. Therefore, persimmon peel may be an effective functional food material.

Effect of Astaxanthin on the Inhibition of Lipid Accumulation in 3T3-L1 Adipocytes via Modulation of Lipogenesis and Fatty Acid Transport Pathways.

Obesity is defined as a condition of excessive fat tissue accumulation. It was the major factor most closely associated with lifestyle-related diseases. In the present study, we investigated the effect of astaxanthin on the inhibition of lipid accumulation in 3T3-L1 adipocytes. 3T3-L1 adipocytes were treated with 0–25 µg/mL of astaxanthin for 0–48 h. The result indicated that astaxanthin significantly decreased the oil Red O stained material (OROSM), intracellular triglyceride accumulation, and glycerol 3-phosphate dehydrogenase (GPDH) activity in 3T3-L1 adipocytes (p < 0.05). At the molecular level, astaxanthin significantly down-regulated the mRNA expression of peroxisome proliferator-activated receptor-γ (PPARγ) in 3T3-L1 adipocytes (p < 0.05). Moreover, target genes of PPARγ on the inhibition of lipogenesis, such as Acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), fatty acid binding protein (aP2), cluster of differentiation 36 (CD36), and lipoprotein lipase (LPL) in 3T3-L1 adipocytes were significantly down-regulated at a time-dependent manner (p < 0.05). These results suggested that astaxanthin efficiently suppressed lipid accumulation in 3T3-L1 adipocytes and its action is associated with the down-regulation of lipogenesis-related genes and the triglyceride accumulation in 3T3-L1 adipocytes. Therefore, astaxanthin can be developed as a potential nutraceutical ingredient for the prevention of obesity in a niche market.

Potential Marker Genes for Predicting Adipogenic Differentiation of Mesenchymal Stromal Cells

Mesenchymal stromal cells (MSCs) are a promising source for tissue engineering of soft connective tissues. However, the differentiation capacity of MSCs varies among individual cell lines. Here, we show marker genes to predict the adipogenic potential of MSCs. To clarify the correlation between gene expression patterns before adipogenic induction and the differentiation level of MSCs after differentiation, we compared mRNA levels of 95 genes and glycerol-3-phosphate dehydrogenase (GPDH) activities in 15 MSC lines (five jaw and 10 ilium MSCs) from 15 donors. Expression profiles of 22 genes before differentiation significantly correlated with GPDH activities after differentiation. Expression levels of 11 out of the 22 genes in highly potent ilium MSCs were at least three times higher compared with jaw MSCs, which have limited differentiation potential. Furthermore, three-dimensional scatter plot for mRNA expression of ITGA5, CDKN2D, and CD74 could completely distinguish highly potent MSCs from poorly potent MSCs for adipogenesis. The treatment of MSC cultures with the anti-ITGA5 antibody reduced adipogenic differentiation of MSCs. Collectively, these results suggest that the three genes play a role in adipogenesis before induction and can serve as predictors to select potent MSCs for adipogenic differentiation.

Phytochemicals derived from soya bean husk exert hypoglycemic and anti-adipogenic properties in cell culture models

PurposeLiterature has shown that phenolic acids and flavonoids are bearing with hypoglycemic and anti-adipogenic properties. Therefore, this study aims to evaluate the possibility of phenolic-rich soya bean husk powder extract (SHPE) in combating diabetes and obesity using in vitro models.Design/methodology/approachThe hypoglycemic properties were evaluated by determining the ability of SHPE (25-100 µg/mL) in inhibiting a-amylase and a-glucosidase enzymes and in triggering insulin secretion in BRIN-BD11 cells. Murine 3T3-L1 adipocytes were used for evaluating the anti-adipogenic properties of SHPE through the determination of relative lipid accumulation, triglyceride content and glycerol-3-phosphate dehydrogenase (GPDH) activity.FindingsThe hypoglycemic properties of SHPE was in the dose-dependent manner, where 100 µg SHPE/mL exhibited a significant higher (p < 0.05) a-amylase inhibitory activity (56.8 ± 0.11 per cent) and insulin secretion activity (0.73 ± 0.02 µg/l) against other concentrations. In contrast to the aforementioned findings, a significant lower a-glucosidase inhibitory activity (52.0 ± 0.44 per cent) was also observed in 100 µg SHPE/mL. Nevertheless, findings revealed that all the SHPE were able to inhibit the activity of a-amylase and a-glucosidase and stimulated the insulin secretion in BRIN-BD11 cells. On the other hand, the anti-adipogenic properties of SHPE were in the reverse dose-dependent manner, where 100 µg SHPE/mL demonstrated a significant lower (p < 0.05) relative lipid accumulation (48.5 ± 0.03 per cent), intracellular triglyceride content (5.7 ± 0.07 mg/dL) and GPDH activity (1.0 ± 0.01 mU/mL). These findings reflected that 100 µg SHPE/mL was a potent anti-adipogenic agent when compared with other concentrations. In conclusion, soya husk could emerge as a potential hypoglycemic and anti-adipogenic agents in in vitro models.Originality/valueThis was the first study to explore the effectiveness of phytochemicals derived from soya bean husk in ameliorating hyperglycemia and adipogenesis. Promising findings that derived from the present study could enable the scientists to re-evaluate the potential use of agricultural wastes, especially in the formulation of nutraceuticals.

Fructose 1,6-Bisphosphate as a Protective Agent for Experimental Fat Grafting.

Fat grafting procedures are considered to be a promising regenerative, cell‐directed therapy; however, their survival is mainly influenced by ischemia condition. Fructose 1,6‐bisphosphate (FBP), as an intermediate in energy metabolism, has the potential to rescue cells and tissues from hypoxic‐ischemic circumstances. In the present study, human lipoaspirates were grafted subcutaneously into nude mice followed by a daily intraperitoneal injection of FBP at different doses for 7 days. Next, the grafts were harvested at different time points till 12 weeks postimplantation and were evaluated for cell viability and function, tissue revascularization and inflammatory cell infiltration using histological analysis, whole‐mount living tissue imaging, glycerol 3‐phosphate dehydrogenase activity assays, and quantitative analysis of gene expression. The results demonstrated that exogenous FBP administration could attenuate the volume and weight reduction of fat graft; meanwhile, FBP enhanced adipocyte viability and function, increased blood vessel formation, and decreased inflammation. Moreover, in vitro cell experiments showed that FBP could promote adipose‐derived stem cell viability and vascular endothelial growth factor (VEGF) mRNA expression in ischemia conditions. Our study indicates that FBP can be used as a protective agent for fat grafting and may be applied in stem cell‐based regenerative medicine. stem cells translational medicine 2019;8:606–616

The glycerol and ethanol production kinetics in low‐temperature wine fermentation using Saccharomyces cerevisiae yeast strains

SummaryIncreasing glycerol production in low‐temperature wine fermentation is of concern for winemakers to improve the quality of wines. The objective of this study was to investigate the effect of 10 different Saccharomyces cerevisiae on the kinetics of production of glycerol, ethanol and the activities of glycerol‐3‐phosphate dehydrogenase (GPD) and alcohol dehydrogenase (ADH) in low‐temperature fermentation. Ethanol production was influenced by temperature, and it was slightly higher at 13 °C than at 25 °C. Glycerol yields were significantly affected by both temperature and strains. More glycerol was produced at 25 °C than at 13 °C because the activity of GPD was higher at 25 °C than at 13 °C. Glycerol production of the different yeast strains was up to 3.19 and 3.18 g L−1 at 25 and 13 °C, respectively. Therefore, isolating the yeast strains with high glycerol production and adaptation to low‐temperature fermentation is still the best method in winemaking.

Grape seed procyanidin extract inhibits adipogenesis and stimulates lipolysis of porcine adipocytes in vitro.

The objective of this article was to evaluate in vitro effect of grape seed procyanidin extract (GSPE) on differentiation, proliferation, and lipolysis of porcine adipocytes, providing a molecular basis for the use of GSPE in pig fat regulation. Primary preadipocytes isolated from subcutaneous adipose tissue of pigs were used as the in vitro cell model. Treatment of GSPE repressed preadipocyte differentiation, as evidenced by reduced lipid accumulation, decreased mRNA expressions of peroxisome proliferator-activated receptor gamma (PPARγ) and fatty acid-binding protein 4 (FABP4), as well as enhanced expressions of preadipocyte factor-1. Activity of glycerol-3-phosphate dehydrogenase (GPDH), one of the most important enzymes in the pathway for triacylglycerol biosynthesis, was also decreased. Furthermore, GSPE could suppress preadipocyte proliferation by inducing G0/G1 cell cycle arrest and cell apoptosis. In porcine mature adipocytes, treatment with GSPE attenuated lipid content and GPDH activity, and the release of both free fatty acid and glycerol were enhanced; mRNA expressions of key lipolytic transcription factors, including hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL), were elevated in GSPE-treated adipocytes. In summary, our results suggest GSPE inhibits porcine preadipocyte differentiation and proliferation and stimulates lipolysis of mature adipocytes, thus providing novel insights for further exploring the use of GSPE as a fat accumulation inhibitor.

Adipogenesis in fish.

White adipose tissue (AT) is the main lipid storage depot in vertebrates. Initially considered to be a simple lipid store, AT has recently been recognized as playing a role as an endocrine organ that is implicated in processes such as energy homeostasis and as a rich source of stem cells. Interest in adipogenesis has increased not only because of the prevalence of obesity, metabolic syndrome and type 2 diabetes in humans, but also in aquaculture because of the excessive fat deposition experienced in some cultured fish species, which may compromise both their welfare and their final product quality. Adipocyte development is well conserved among vertebrates, and this conservation has facilitated the rapid characterization of several adipogenesis models in fish. This Review presents the main findings of adipogenesis research based in primary cultures of the preadipocytes of farmed fish species. Zebrafish has emerged as an excellent model for studying the early stages of adipocyte fish development in vivo Nevertheless, larger fish species are more suitable for the isolation of preadipocytes from visceral AT and for studies in which preadipocytes are differentiated in vitro to form mature adipocytes. Differentiated adipocytes contain lipid droplets and express adipocyte marker genes such as those encoding the peroxisome proliferator activated receptor γ (pparγ), CCAAT-enhancer-binding protein α (c/ebpα), lipoprotein lipase (lpl), fatty acid synthase (fas), fatty acid binding protein 11 (fabp11), fatty acid transporter protein1 (fatp1), adiponectin and leptin. Differentiated adipocytes also have elevated glycerol 3-phosphate (G3P) dehydrogenase (GPDH) activity. To better understand fish adipocyte development and regulation, different adipokines, fatty acids, growth factors and PPAR agonists have been studied, providing relevant insights into which factors affect these processes and counterbalance AT dysregulation.

Suppressive effects of aryl-hydrocarbon receptor repressor on adipocyte differentiation in 3T3-L1 cells

The aryl-hydrocarbon receptor repressor (AhRR) negatively regulates aryl-hydrocarbon receptor (AhR) signaling via its inhibitory transactivation. AhR is well known to suppress adipocyte differentiation, but the function of AhRR during adipogenesis is unclear. The purpose of this study was to investigate the role of AhRR in adipocyte differentiation using 3T3-L1 cells. During the early phase of differentiation, AhRR expression was transiently induced, but throughout the entire differentiation process, low levels of AhR expression were maintained. AhRR knockdown significantly increased not only glycerol-3-phosphate dehydrogenase (GPDH) activity but also lipid accumulation inside the cells. AhRR overexpression clearly reduced GPDH activity and lipid accumulation, indicating that AhRR upregulation during the early stage of adipogenesis suppresses adipocyte differentiation. Since AhRR knockdown increases the expression and activity of peroxisome proliferator-activated receptor γ (PPARγ), AhRR negatively regulates PPARγ during adipogenesis. In summary, similar to AhR, AhRR acts as an inhibitor of adipocyte differentiation. In addition to controlling the negative feedback loop of AhR, AhRR might be involved in other functions, especially in adipocyte differentiation processes.

ZBTB16 Overexpression Enhances White Adipogenesis and Induces Brown-Like Adipocyte Formation of Bovine White Intramuscular Preadipocytes

Background/Aims: Our study aims to characterize functions of ZBTB16 gene in the process of intramuscular fat (IMF) deposition and metabolism of bovine, thereby providing insights into mechanisms for the use of ZBTB16 in fat management. Methods: Primary preadipocytes derived from bovine IMF tissue were isolated and used as the in vitro cell model. An adenovirus Ad-ZBTB16 was transfected into bovine preadipocytes to overexpress the ZBTB16 gene. By using real-time quantitative PCR (RT-qPCR), western blotting, Oil Red-O staining, glycerol-3-phosphate dehydrogenase (GPDH) activity assay, and cell counting kit-8 (CCK-8) test, adipogenic and proliferative signals in adipocytes were monitored to investigate effects of ZBTB16 on adipogenesis of bovine preadipocytes. Results: After transfection, mRNA and protein levels of ZBTB16 gene were significantly increased. Enhanced ZBTB16 significantly promoted preadipocyte differentiation, as evidenced by accelerated lipid accumulation, enhanced GPDH activity, consistently increased mRNA expressions of adipogenic key transcription factors PPARγ, C/EBPα, FABP4, and ADIPOQ, and markedly increased protein expressions of PPARγ and FABP4. No difference was observed concerning proliferation of preadipocytes after treatment with Ad-ZBTB16. Furthermore, relative mRNA levels of brown adipocyte selective genes (PRDM16, UCP1, Cidea, Cox8b, and PGC-1α) and beige adipocyte selective genes (CD137, TMEM26, and Tbx1) as well as UCP1 protein expression were significantly increased by Ad-ZBTB16. Meanwhile, Ad-ZBTB16 treatment remarkably induced mitochondrial biogenesis and increased relative mitochondrial DNA (mtDNA) copy number in bovine adipocytes. Conclusion: These results suggest that ZBTB16 overexpression can promote white adipogenesis and induce brown-like adipocyte formation for bovine white intramuscular preadipocytes.

Peripheral neuropeptide Y differentially influences adipogenesis and lipolysis in chicks from lines selected for low or high body weight

Neuropeptide Y (NPY) stimulates appetite and promotes lipid deposition. We demonstrated a differential sensitivity in the food intake response to central NPY in chicks from lines selected for low (LWS) or high (HWS) body weight, but have not reported whether such differences exist in the periphery. At 5days, LWS and HWS chicks were intraperitoneally injected with 0 (vehicle), 60, or 120μg/kg BW NPY and subcutaneous adipose tissue and plasma were collected at 1, 3, 6, 12, and 24h (n=12). NPY injection increased glycerol-3-phosphate dehydrogenase (G3PDH) activity at 1 and 3h and reduced plasma non-esterified fatty acids (NEFAs) at 1 and 12h. G3PDH activity was greater in HWS than LWS while NEFAs were greater in LWS. At 1h, peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT/enhancer binding protein (C/EBP)α, and microsomal triglyceride transfer protein (MTTP) mRNAs were reduced in NPY-injected chicks whereas NPY receptor 1 (NPYR1) was increased. Expression of stearoyl-CoA desaturase (SCD1) was increased by NPY at 1h in HWS but not LWS. PPARγ (3 and 6h), C/EBPβ (3h), C/EBPα (6h) and NPYR1 and 2 (24h) mRNAs were greater in NPY- than vehicle-injected chicks. At several times, adipose triglyceride lipase, MTTP, perilipin 1, NPYR1, and NPYR2 mRNAs were greater in LWS than HWS, while expression of SCD1, glycerol-3-phosphate acyltransferase 3 and lipoprotein lipase was greater in HWS than LWS. Thus, NPY promotes fat deposition and inhibits lipolysis in chicks, with line differences indicative of greater rates of lipolysis in LWS and adipogenesis in HWS.

Fatty Acids Have Different Adipogenic Differentiation Potentials in Stromal Vascular Cells Isolated from Abdominal Fat in Laying Hens.

This study was conducted to examine the effects of fatty acids (FA) with/without chicken serum (CS) on the expression of adipogenic transcripts and adipogenesis in chicken stromal vascular cells (SVC). In experiment 1, SVC were grown in DMEM containing 10% FBS (Control) and treated with 300µM oleic acid (OLA)+FBS, linoleic acid (LNA)+FBS, palmitic acid (PAM)+FBS, or stearic acid (STA)+FBS for 48h. In experiment 2, cells were grown in DMEM containing 5% CS and treated with 300µM OLA (CS+OLA), PAM (CS+PAM), STA (CS+STA) or 200µM LNA (CS+LNA) for 48h. Adipogenesis was determined using Oil Red O staining and glycerol-3-phosphate dehydrogenase (GPDH) activity. The proportion of OLA, PAM, or STA was increased (P<0.05) in SVC grown in either FBS or CS with OLA, PAM or STA. Adipogenesis was induced in FBS+OLA, FBS+LNA, FBS+PAM, FBS+STA, CS+OLA, CS+LNA, CS+PAM, or CS+SAT compared to FBS. GPDH activity was significantly higher in FBS+OLA and FBS+LNA than one in FBS. Compared to FBS, the expression of FABP4 mRNA increased (P<0.05) in FBS+OLA, FBS+LNA, or FBS+PAM, whereas that of C/EBPα, C/EBPβ, and ATGL increased (P<0.05) in FBS+OLA or FBS+LNA cells. Expression of FABP4 and C/EBPβ mRNA was higher in CS, CS+OLA, CS+LNA, CS+PAM, or CS+SAT compared with (FBS, whereas the expression of ATGL and C/EBPα was higher in CS, CS+OLA, or CS+LNA than FBS cells. In conclusion, these results showed that FA have different potentials to induce adipogenesis, LNA is the most potent among the tested FA, and these potentials can be improved in the presence of CS.

Experimentally Induced Bleaching in the Sea Anemone Exaiptasia Supports Glucose as a Main Metabolite Associated with Its Symbiosis

Our current understanding of carbon exchange between partners in the Symbiodinium-cnidarian symbioses is still limited, even though studies employing carbon isotopes have made us aware of the metabolic complexity of this exchange. We examined glycerol and glucose metabolism to better understand how photosynthates are exchanged between host and symbiont. The levels of these metabolites were compared between symbiotic and bleached Exaiptasia pallida anemones, assaying enzymes directly involved in their metabolism. We measured a significant decrease of glucose levels in bleached animals but a significant increase in glycerol and G3P pools, suggesting that bleached animals degrade lipids to compensate for the loss of symbionts and seem to rely on symbiotic glucose. The lower glycerol 3-phosphate dehydrogenase but higher glucose 6-phosphate dehydrogenase specific activities measured in bleached animals agree with a metabolic deficit mainly due to the loss of glucose from the ruptured symbiosis. These results corroborate previous observations on carbon translocation from symbiont to host in the sea anemone Exaiptasia, where glucose was proposed as a main translocated metabolite. To better understand photosynthate translocation and its regulation, additional research with other symbiotic cnidarians is needed, in particular, those with calcium carbonate skeletons.