TY - JOUR

T1 - Metabolic gene expression profile in circulating mononuclear cells reflects obesity-associated metabolic inflexibility

AU - Baig, Sonia

AU - Parvaresh Rizi, Ehsan

AU - Shabeer, Muhammad

AU - Chhay, Vanna

AU - Mok, Shao Feng

AU - Loh, Tze Ping

AU - Magkos, Faidon

AU - Vidal-Puig, Antonio

AU - Tai, E Shyong

AU - Khoo, Chin Meng

AU - Toh, Sue-Anne

N1 - (Ekstern)

PY - 2016

Y1 - 2016

N2 - Background: Obesity is associated with an impaired ability to switch from fatty acid to glucose oxidation during the fasted to fed transition, particularly in skeletal muscle. However, whether such metabolic inflexibility is reflected at the gene transcription level in circulatory mononuclear cells (MNC) is not known.Methods: The whole-body respiratory quotient (RQ) and transcriptional regulation of genes involved in carbohydrate and lipid metabolism in MNC were measured during fasting and in response (up to 6 h) to high-carbohydrate and high-fat meals in nine lean insulin-sensitive and nine obese insulin-resistant men.Results: Compared to lean subjects, obese subjects had an impaired ability to increase RQ and switch from fatty acid to glucose oxidation following the high-carbohydrate meal (interaction term P < 0.05). This was accompanied by an impaired induction of genes involved in oxidative metabolism of glucose in MNC, such as phosphofructokinase (PFK), pyruvate dehydrogenase kinase 4 (PDK4), peroxisome proliferator-activated receptor alpha (PPARα) and uncoupling protein 3 (UCP3) and increased expression of genes involved in fatty acid metabolism, such as fatty acid translocase (FAT/CD36) and fatty acid synthase (FASN) (P < 0.05). On the contrary, there were no differences in the gene expression profiles between lean and obese subjects following the high-fat meal.Conclusions: Postprandial expression profiles of genes involved in glucose and fatty acid metabolism in the MNC reflect the differing metabolic flexibility phenotypes of our cohort of lean and obese individuals. These differences in metabolic flexibility between the lean and obese are elicited by an acute meal challenge that is rich in carbohydrate but not fat.

AB - Background: Obesity is associated with an impaired ability to switch from fatty acid to glucose oxidation during the fasted to fed transition, particularly in skeletal muscle. However, whether such metabolic inflexibility is reflected at the gene transcription level in circulatory mononuclear cells (MNC) is not known.Methods: The whole-body respiratory quotient (RQ) and transcriptional regulation of genes involved in carbohydrate and lipid metabolism in MNC were measured during fasting and in response (up to 6 h) to high-carbohydrate and high-fat meals in nine lean insulin-sensitive and nine obese insulin-resistant men.Results: Compared to lean subjects, obese subjects had an impaired ability to increase RQ and switch from fatty acid to glucose oxidation following the high-carbohydrate meal (interaction term P < 0.05). This was accompanied by an impaired induction of genes involved in oxidative metabolism of glucose in MNC, such as phosphofructokinase (PFK), pyruvate dehydrogenase kinase 4 (PDK4), peroxisome proliferator-activated receptor alpha (PPARα) and uncoupling protein 3 (UCP3) and increased expression of genes involved in fatty acid metabolism, such as fatty acid translocase (FAT/CD36) and fatty acid synthase (FASN) (P < 0.05). On the contrary, there were no differences in the gene expression profiles between lean and obese subjects following the high-fat meal.Conclusions: Postprandial expression profiles of genes involved in glucose and fatty acid metabolism in the MNC reflect the differing metabolic flexibility phenotypes of our cohort of lean and obese individuals. These differences in metabolic flexibility between the lean and obese are elicited by an acute meal challenge that is rich in carbohydrate but not fat.

KW - Faculty of Science

KW - Mononuclear cells

KW - Metabolic flexibility

KW - Gene expression

KW - Macronutrients

KW - Obesity

U2 - 10.1186/s12986-016-0135-5

DO - 10.1186/s12986-016-0135-5

M3 - Journal article

C2 - 27800008

VL - 13

JO - Nutrition & Metabolism

JF - Nutrition & Metabolism

SN - 1743-7075

M1 - 74

ER -