Supranutritional selenium induces alterations in molecular targets related to energy metabolism in skeletal muscle and visceral adipose tissue of pigs.
While selenium (Se) is an essential micronutrient for humans, epidemiological studies have raised concern that supranutritional Se intake may increase the risk of developing Type 2 diabetes mellitus (T2DM). We aimed to determine the impact of Se at a dose and source frequently ingested by humans on markers of insulin sensitivity and signalling. Male pigs were fed either a Se-adequate (0.17 mg Se/kg) or a Se-supranutritional (0.50 mg Se/kg; high-Se) diet. After 16 weeks of intervention, fasting plasma insulin and cholesterol levels were non-significantly increased in the high-Se pigs, whereas fasting glucose concentrations did not differ between the two groups. In skeletal muscle of high-Se pigs, glutathione peroxidase activity was increased, gene expression of forkhead box O1 transcription factor and peroxisomal proliferator-activated receptor-γ coactivator 1α were increased and gene expression of the glycolytic enzyme pyruvate kinase was decreased. In visceral adipose tissue of high-Se pigs, mRNA levels of sterol regulatory element-binding transcription factor 1 were increased, and the phosphorylation of Akt, AMP-activated kinase and mitogen-activated protein kinases was affected. In conclusion, dietary Se oversupply may affect expression and activity of proteins involved in energy metabolism in major insulin target tissues, though this is probably not sufficient to induce diabetes.
Institute for Biochemistry and Molecular Biology I, Heinrich-Heine-University, Universitätsstrasse 1, D-40225 Düsseldorf, Germany.
Antonio
A
Pinto
Darren T
DT
Juniper
Mert
M
Sanil
Linda
L
Morgan
Lynne
L
Clark
Helmut
H
Sies
Margaret P
MP
Rayman
Holger
H
Steinbrenner
D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000097:blood; D019587:Dietary Supplements; D004734:Energy Metabolism / Q000187:drug effects* / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects*; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D050152:Intra-Abdominal Fat / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D011770:Pyruvate Kinase / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D012643:Selenium / Q000008:administration & dosage*; D013552:Swine; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D015415:Biomarkers; D007328:Insulin; D012333:RNA, Messenger; D014157:Transcription Factors; D005979:Glutathione Peroxidase; D011770:Pyruvate Kinase; D051057:Proto-Oncogene Proteins c-akt; D020928:Mitogen-Activated Protein Kinases; D055372:AMP-Activated Protein Kinases; D012643:Selenium