Benzylglucosinolate Derived Isothiocyanate from Tropaeolum majus Reduces Gluconeogenic Gene and Protein Expression in Human Cells.
Nasturtium (Tropaeolum majus L.) contains high concentrations of benzylglcosinolate. We found that a hydrolysis product of benzyl glucosinolate-the benzyl isothiocyanate (BITC)-modulates the intracellular localization of the transcription factor Forkhead box O 1 (FOXO1). FoxO transcription factors can antagonize insulin effects and trigger a variety of cellular processes involved in tumor suppression, longevity, development and metabolism. The current study evaluated the ability of BITC-extracted as intact glucosinolate from nasturtium and hydrolyzed with myrosinase-to modulate i) the insulin-signaling pathway, ii) the intracellular localization of FOXO1 and, iii) the expression of proteins involved in gluconeogenesis, antioxidant response and detoxification. Stably transfected human osteosarcoma cells (U-2 OS) with constitutive expression of FOXO1 protein labeled with GFP (green fluorescent protein) were used to evaluate the effect of BITC on FOXO1. Human hepatoma HepG2 cell cultures were selected to evaluate the effect on gluconeogenic, antioxidant and detoxification genes and protein expression. BITC reduced the phosphorylation of protein kinase B (AKT/PKB) and FOXO1; promoted FOXO1 translocation from cytoplasm into the nucleus antagonizing the insulin effect; was able to down-regulate the gene and protein expression of gluconeogenic enzymes; and induced the gene expression of antioxidant and detoxification enzymes. Knockdown analyses with specific siRNAs showed that the expression of gluconeogenic genes was dependent on nuclear factor (erythroid derived)-like2 (NRF2) and independent of FOXO1, AKT and NAD-dependent deacetylase sirtuin-1 (SIRT1). The current study provides evidence that BITC might have a role in type 2 diabetes T2D by reducing hepatic glucose production and increasing antioxidant resistance.
Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbrücke, Nuthetal, Germany.|Department of Nutrition and Biochemistry, Sciences Faculty-Pontificia Universidad Javeriana, Bogotá D.C, Colombia.
Valentina
V
Guzmán-Pérez
Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbrücke, Nuthetal, Germany.|Department of Endocrinology, Diabetes and Nutrition, Charité- Universitätsmedizin Berlin, Berlin, Germany.|Department of Plant Quality, Leibniz-Institute of Vegetable and Ornamental Crops Großbeeren/Erfurt e.V, Erfurt, Germany.
Christiane
C
Bumke-Vogt
Department of Plant Quality, Leibniz-Institute of Vegetable and Ornamental Crops Großbeeren/Erfurt e.V, Erfurt, Germany.
Monika
M
Schreiner
Department of Plant Quality, Leibniz-Institute of Vegetable and Ornamental Crops Großbeeren/Erfurt e.V, Erfurt, Germany.
Inga
I
Mewis
Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbrücke, Nuthetal, Germany.
Andrea
A
Borchert
Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbrücke, Nuthetal, Germany.|Department of Endocrinology, Diabetes and Nutrition, Charité- Universitätsmedizin Berlin, Berlin, Germany.
Andreas F H
AF
Pfeiffer
D000111:Acetylcysteine / Q000494:pharmacology; D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000975:Antioxidants / Q000494:pharmacology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism; D000071161:Forkhead Box Protein O1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D055785:Gene Knockdown Techniques; D005943:Gluconeogenesis / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology; D005952:Glucose-6-Phosphatase / Q000235:genetics; D056945:Hep G2 Cells; D006801:Humans; D007004:Hypoglycemic Agents / Q000737:chemistry / Q000494:pharmacology; D017879:Isothiocyanates / Q000737:chemistry / Q000494:pharmacology; D051267:NF-E2-Related Factor 2 / Q000037:antagonists & inhibitors / Q000235:genetics; D019764:Phosphoenolpyruvate Carboxykinase (ATP) / Q000235:genetics; D010946:Plants, Medicinal / Q000737:chemistry; D021381:Protein Transport / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D056564:Sirtuin 1 / Q000037:antagonists & inhibitors / Q000235:genetics; D013861:Thiocyanates / Q000737:chemistry / Q000494:pharmacology*; D013863:Thioglucosides / Q000737:chemistry / Q000494:pharmacology*; D032388:Tropaeolum / Q000737:chemistry*
D000975:Antioxidants; C085126:FOXO1 protein, human; D000071161:Forkhead Box Protein O1; D007004:Hypoglycemic Agents; D017879:Isothiocyanates; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins; D013861:Thiocyanates; D013863:Thioglucosides; C408882:benzylglucosinolic acid; C031403:benzyl isothiocyanate; D051057:Proto-Oncogene Proteins c-akt; D005952:Glucose-6-Phosphatase; C447939:SIRT1 protein, human; D056564:Sirtuin 1; C000597251:PCK2 protein, human; D019764:Phosphoenolpyruvate Carboxykinase (ATP); D000111:Acetylcysteine