Limits...
White-to-brite conversion in human adipocytes promotes metabolic reprogramming towards fatty acid anabolic and catabolic pathways.

Barquissau V, Beuzelin D, Pisani DF, Beranger GE, Mairal A, Montagner A, Roussel B, Tavernier G, Marques MA, Moro C, Guillou H, Amri EZ, Langin D - Mol Metab (2016)

Bottom Line: This conversion is associated with transcriptional changes leading to major metabolic adaptations.Conversion of human white fat cells into brite adipocytes results in a major metabolic reprogramming inducing fatty acid anabolic and catabolic pathways.PDK4 redirects glucose from oxidation towards triglyceride synthesis and favors the use of fatty acids as energy source for uncoupling mitochondria.

View Article: PubMed Central - PubMed

Affiliation: INSERM, UMR 1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, Paul Sabatier University, France.

ABSTRACT

Objective: Fat depots with thermogenic activity have been identified in humans. In mice, the appearance of thermogenic adipocytes within white adipose depots (so-called brown-in-white i.e., brite or beige adipocytes) protects from obesity and insulin resistance. Brite adipocytes may originate from direct conversion of white adipocytes. The purpose of this work was to characterize the metabolism of human brite adipocytes.

Methods: Human multipotent adipose-derived stem cells were differentiated into white adipocytes and then treated with peroxisome proliferator-activated receptor (PPAR)γ or PPARα agonists between day 14 and day 18. Gene expression profiling was determined using DNA microarrays and RT-qPCR. Variations of mRNA levels were confirmed in differentiated human preadipocytes from primary cultures. Fatty acid and glucose metabolism was investigated using radiolabelled tracers, Western blot analyses and assessment of oxygen consumption. Pyruvate dehydrogenase kinase 4 (PDK4) knockdown was achieved using siRNA. In vivo, wild type and PPARα- mice were treated with a β3-adrenergic receptor agonist (CL316,243) to induce appearance of brite adipocytes in white fat depot. Determination of mRNA and protein levels was performed on inguinal white adipose tissue.

Results: PPAR agonists promote a conversion of white adipocytes into cells displaying a brite molecular pattern. This conversion is associated with transcriptional changes leading to major metabolic adaptations. Fatty acid anabolism i.e., fatty acid esterification into triglycerides, and catabolism i.e., lipolysis and fatty acid oxidation, are increased. Glucose utilization is redirected from oxidation towards glycerol-3-phophate production for triglyceride synthesis. This metabolic shift is dependent on the activation of PDK4 through inactivation of the pyruvate dehydrogenase complex. In vivo, PDK4 expression is markedly induced in wild-type mice in response to CL316,243, while this increase is blunted in PPARα- mice displaying an impaired britening response.

Conclusions: Conversion of human white fat cells into brite adipocytes results in a major metabolic reprogramming inducing fatty acid anabolic and catabolic pathways. PDK4 redirects glucose from oxidation towards triglyceride synthesis and favors the use of fatty acids as energy source for uncoupling mitochondria.

No MeSH data available.


Related in: MedlinePlus

Britening of white adipocytes promotes a shift of glucose metabolism from oxidation towards glycerol production. Glucose metabolism was investigated in 18 day-differentiated hMADS cells treated or not with rosiglitazone or GW7647 for the last 4 days. (A) Glucose transport in the presence or not of 100 nM insulin. (B) Gene expression levels of the glucose transporters GLUT1 and GLUT4 and GLUT1 protein level. (C) Insulin sensitivity estimated by the insulin stimulated-to-basal glucose uptake ratio. (D) Pyruvate uptake, (E) pyruvate oxidation and (F) pyruvate release into the medium in the presence or not of 100 nM insulin. (G) Glyceroneogenesis assessed by incorporation of pyruvic acid into the glycerol moiety of neutral lipids. (H) PCK1 mRNA and protein levels. (I) Lipolysis measured by oleic acid release into the medium after stimulation by the β-adrenergic agonist, isoproterenol. (J) Gene expression levels of the four PDK isoforms. (K) PDK4 and Ser293-phosphorylated PDHE1α protein levels. Data represent mean ± SEM expressed as percentage of control (n = 6–12). Open bars: control cells (C), full bars: rosiglitazone-treated cells (R), hatched bars: GW7647-treated cells (GW). *: p < 0.05 for R or GW vs. C; **: p < 0.01; ***: p < 0.001. $: p < 0.05 for insulin vs. unstimulated condition; $$$: p < 0.001. ##: p < 0.01 for R vs. GW; ###: p < 0.001.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4837301&req=5

fig3: Britening of white adipocytes promotes a shift of glucose metabolism from oxidation towards glycerol production. Glucose metabolism was investigated in 18 day-differentiated hMADS cells treated or not with rosiglitazone or GW7647 for the last 4 days. (A) Glucose transport in the presence or not of 100 nM insulin. (B) Gene expression levels of the glucose transporters GLUT1 and GLUT4 and GLUT1 protein level. (C) Insulin sensitivity estimated by the insulin stimulated-to-basal glucose uptake ratio. (D) Pyruvate uptake, (E) pyruvate oxidation and (F) pyruvate release into the medium in the presence or not of 100 nM insulin. (G) Glyceroneogenesis assessed by incorporation of pyruvic acid into the glycerol moiety of neutral lipids. (H) PCK1 mRNA and protein levels. (I) Lipolysis measured by oleic acid release into the medium after stimulation by the β-adrenergic agonist, isoproterenol. (J) Gene expression levels of the four PDK isoforms. (K) PDK4 and Ser293-phosphorylated PDHE1α protein levels. Data represent mean ± SEM expressed as percentage of control (n = 6–12). Open bars: control cells (C), full bars: rosiglitazone-treated cells (R), hatched bars: GW7647-treated cells (GW). *: p < 0.05 for R or GW vs. C; **: p < 0.01; ***: p < 0.001. $: p < 0.05 for insulin vs. unstimulated condition; $$$: p < 0.001. ##: p < 0.01 for R vs. GW; ###: p < 0.001.

Mentions: Basal and insulin-stimulated glucose uptakes were decreased in brite adipocytes (Figure 3A). This was consistent with decreased mRNA and protein levels of the glucose transporter GLUT1 (Figure 3B). GLUT1 expression was strongly correlated with basal glucose transport (Figure S4A). Insulin sensitivity evaluated by the insulin stimulated-to-basal glucose uptake ratio was preserved (Figure 3C) as was gene expression level of the insulin-responsive glucose transporter GLUT4 (Figure 3B).


White-to-brite conversion in human adipocytes promotes metabolic reprogramming towards fatty acid anabolic and catabolic pathways.

Barquissau V, Beuzelin D, Pisani DF, Beranger GE, Mairal A, Montagner A, Roussel B, Tavernier G, Marques MA, Moro C, Guillou H, Amri EZ, Langin D - Mol Metab (2016)

Britening of white adipocytes promotes a shift of glucose metabolism from oxidation towards glycerol production. Glucose metabolism was investigated in 18 day-differentiated hMADS cells treated or not with rosiglitazone or GW7647 for the last 4 days. (A) Glucose transport in the presence or not of 100 nM insulin. (B) Gene expression levels of the glucose transporters GLUT1 and GLUT4 and GLUT1 protein level. (C) Insulin sensitivity estimated by the insulin stimulated-to-basal glucose uptake ratio. (D) Pyruvate uptake, (E) pyruvate oxidation and (F) pyruvate release into the medium in the presence or not of 100 nM insulin. (G) Glyceroneogenesis assessed by incorporation of pyruvic acid into the glycerol moiety of neutral lipids. (H) PCK1 mRNA and protein levels. (I) Lipolysis measured by oleic acid release into the medium after stimulation by the β-adrenergic agonist, isoproterenol. (J) Gene expression levels of the four PDK isoforms. (K) PDK4 and Ser293-phosphorylated PDHE1α protein levels. Data represent mean ± SEM expressed as percentage of control (n = 6–12). Open bars: control cells (C), full bars: rosiglitazone-treated cells (R), hatched bars: GW7647-treated cells (GW). *: p < 0.05 for R or GW vs. C; **: p < 0.01; ***: p < 0.001. $: p < 0.05 for insulin vs. unstimulated condition; $$$: p < 0.001. ##: p < 0.01 for R vs. GW; ###: p < 0.001.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837301&req=5

fig3: Britening of white adipocytes promotes a shift of glucose metabolism from oxidation towards glycerol production. Glucose metabolism was investigated in 18 day-differentiated hMADS cells treated or not with rosiglitazone or GW7647 for the last 4 days. (A) Glucose transport in the presence or not of 100 nM insulin. (B) Gene expression levels of the glucose transporters GLUT1 and GLUT4 and GLUT1 protein level. (C) Insulin sensitivity estimated by the insulin stimulated-to-basal glucose uptake ratio. (D) Pyruvate uptake, (E) pyruvate oxidation and (F) pyruvate release into the medium in the presence or not of 100 nM insulin. (G) Glyceroneogenesis assessed by incorporation of pyruvic acid into the glycerol moiety of neutral lipids. (H) PCK1 mRNA and protein levels. (I) Lipolysis measured by oleic acid release into the medium after stimulation by the β-adrenergic agonist, isoproterenol. (J) Gene expression levels of the four PDK isoforms. (K) PDK4 and Ser293-phosphorylated PDHE1α protein levels. Data represent mean ± SEM expressed as percentage of control (n = 6–12). Open bars: control cells (C), full bars: rosiglitazone-treated cells (R), hatched bars: GW7647-treated cells (GW). *: p < 0.05 for R or GW vs. C; **: p < 0.01; ***: p < 0.001. $: p < 0.05 for insulin vs. unstimulated condition; $$$: p < 0.001. ##: p < 0.01 for R vs. GW; ###: p < 0.001.
Mentions: Basal and insulin-stimulated glucose uptakes were decreased in brite adipocytes (Figure 3A). This was consistent with decreased mRNA and protein levels of the glucose transporter GLUT1 (Figure 3B). GLUT1 expression was strongly correlated with basal glucose transport (Figure S4A). Insulin sensitivity evaluated by the insulin stimulated-to-basal glucose uptake ratio was preserved (Figure 3C) as was gene expression level of the insulin-responsive glucose transporter GLUT4 (Figure 3B).

Bottom Line: This conversion is associated with transcriptional changes leading to major metabolic adaptations.Conversion of human white fat cells into brite adipocytes results in a major metabolic reprogramming inducing fatty acid anabolic and catabolic pathways.PDK4 redirects glucose from oxidation towards triglyceride synthesis and favors the use of fatty acids as energy source for uncoupling mitochondria.

View Article: PubMed Central - PubMed

Affiliation: INSERM, UMR 1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, Paul Sabatier University, France.

ABSTRACT

Objective: Fat depots with thermogenic activity have been identified in humans. In mice, the appearance of thermogenic adipocytes within white adipose depots (so-called brown-in-white i.e., brite or beige adipocytes) protects from obesity and insulin resistance. Brite adipocytes may originate from direct conversion of white adipocytes. The purpose of this work was to characterize the metabolism of human brite adipocytes.

Methods: Human multipotent adipose-derived stem cells were differentiated into white adipocytes and then treated with peroxisome proliferator-activated receptor (PPAR)γ or PPARα agonists between day 14 and day 18. Gene expression profiling was determined using DNA microarrays and RT-qPCR. Variations of mRNA levels were confirmed in differentiated human preadipocytes from primary cultures. Fatty acid and glucose metabolism was investigated using radiolabelled tracers, Western blot analyses and assessment of oxygen consumption. Pyruvate dehydrogenase kinase 4 (PDK4) knockdown was achieved using siRNA. In vivo, wild type and PPARα- mice were treated with a β3-adrenergic receptor agonist (CL316,243) to induce appearance of brite adipocytes in white fat depot. Determination of mRNA and protein levels was performed on inguinal white adipose tissue.

Results: PPAR agonists promote a conversion of white adipocytes into cells displaying a brite molecular pattern. This conversion is associated with transcriptional changes leading to major metabolic adaptations. Fatty acid anabolism i.e., fatty acid esterification into triglycerides, and catabolism i.e., lipolysis and fatty acid oxidation, are increased. Glucose utilization is redirected from oxidation towards glycerol-3-phophate production for triglyceride synthesis. This metabolic shift is dependent on the activation of PDK4 through inactivation of the pyruvate dehydrogenase complex. In vivo, PDK4 expression is markedly induced in wild-type mice in response to CL316,243, while this increase is blunted in PPARα- mice displaying an impaired britening response.

Conclusions: Conversion of human white fat cells into brite adipocytes results in a major metabolic reprogramming inducing fatty acid anabolic and catabolic pathways. PDK4 redirects glucose from oxidation towards triglyceride synthesis and favors the use of fatty acids as energy source for uncoupling mitochondria.

No MeSH data available.


Related in: MedlinePlus