Lupin seed hydrolysate promotes G-protein-coupled receptor, intracellular Ca2+ and enhanced glycolytic metabolism-mediated insulin secretion from BRIN-BD11 pancreatic beta cells. (15th January 2019)

• Record Type: Journal Article
• Authors: Tapadia, Mrunmai; Carlessi, Rodrigo; Johnson, Stuart; Utikar, Ranjeet; Newsholme, Philip
• Is Part Of: Molecular and cellular endocrinology. Volume 480(2019)
• Page Start: 83
• Page End: 96
• Publication Date: 2019-01-15
• Subjects: Lupin -- Hypoglycaemic -- Insulinotropic -- β-Cells -- Gαq protein -- Nutraceutical; T2D type 2 diabetes -- AMPK AMP activated kinase -- K-ATP ATP sensitive K+ channel -- GPCR G-protein coupled receptor -- cAMP cyclic AMP -- PKA protein kinase A -- PLC phospholipase C -- PKC protein kinase C -- CRE cAMP response element -- CREB cAMP regulatory element binding -- E:Ex enzyme: extract ratio -- DH degree of hydrolysis -- OPA o-phthalaldehyde -- SEC size exclusion chromatogram -- KRBB Kreb Ringer bicarbonate buffer -- FCCP carbonilcyanide p-trifluoromethoxyphenylhydrazone -- ECAR extracellular acidification rate -- OCR oxygen consumption rate -- FSC forward side scatter -- SSC side scatter -- 2-NBDG 2-(N(7-nitrobenz-2-oxa-1, 3-diazol-4-yl)amino)-2-deoxyglucose -- PI propidium iodide -- RIPA radioimmunoprecipitation buffer -- TBST tween 20 containing BSA -- MWCO molecular weight cutoff -- GSIS glucose stimulated insulin secretion -- GLP-1 glucagon like peptide-1 -- GLP-1R GLP-1 receptor -- AC adenylate cyclase -- IP3 inositol triphosphate -- DAG diacyl glycerol -- EPAC2 exchange protein directly activated by cAMP 2 -- GDP guanosine diphosphate -- GTP guanosine triphosphate -- phosphatidylinositol 4 5-biphosphate (PIP2). MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide) -- DMSO Dimethyl sulfoxide -- MCT Monocarboxylate transporter; Endocrinology -- Periodicals; Molecular biology -- Periodicals; Cytology -- Periodicals; Endocrinology -- Periodicals; Hormones -- Periodicals; Endocrinologie -- Périodiques; Cytology; Endocrinology; Molecular biology; Periodicals; 573.4
• DOI: 10.1016/j.mce.2018.10.015
• Languages: English
• ISSNs: 0303-7207

Abstract

Abstract: Lupin seed proteins have been reported to exhibit hypoglycaemic effects in animals and humans following oral administration, however little is known about its mechanism of action. This study investigated the signalling pathway(s) responsible for the insulinotropic effect of the hydrolysate obtained from lupin ( Lupinus angustifolius L.) seed extracts utilizing BRIN-BD11 β-cells. The extract was treated with digestive enzymes to give a hydrolysate rich in biomolecules ≤7 kDa. Cells exhibited hydrolysate induced dose-dependent stimulation of insulin secretion and enhanced intracellular Ca 2+ and glucose metabolism. The stimulatory effect of the hydrolysate was potentiated by depolarizing concentrations of KCl and was blocked by inhibitors of the ATP sensitive K + channel, Gαq protein, phospholipase C (PLC) and protein kinase C (PKC). These findings reveal a novel mechanism for lupin hydrolysate stimulated insulin secretion via Gαq mediated signal transduction (Gαq /PLC/PKC) in the β-cells. Thus, lupin hydrolysates may have potential for nutraceutical treatment in type 2 diabetes. Highlights: Lupin hydrolysate promotes insulin secretion in pancreatic β cells. Mechanism involves activation of a Gαq -PLC-PKC pathway. Hydrolysate-induced effects are glucose permissive and involves enhanced glycolysis. Hydrolysate promotes membrane depolarisation and release of intracellular Ca 2+ .