Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2010-6-14
pubmed:abstractText
Besides its role as a carboxylase prosthetic group, biotin has important effects on gene expression. However, the molecular mechanisms through which biotin exerts these effects are largely unknown. We previously found that biotin increases pancreatic glucokinase expression. We have now explored the mechanisms underlying this effect. Pancreatic islets from Wistar rats were treated with biotin, in the presence or absence of different types of inhibitors. Glucokinase mRNA and 18s rRNA abundance were determined by real-time PCR. Adenosine triphosphate (ATP) content was analyzed by fluorometry. Biotin treatment increased glucokinase mRNA abundance approximately one fold after 2 h; the effect was sustained up to 24 h. Inhibition of soluble guanylate cyclase or protein kinase G (PKG) signalling suppressed biotin-induced glucokinase expression. The cascade of events downstream of PKG in biotin-mediated gene transcription is not known. We found that inhibition of insulin secretion with diazoxide or nifedipine prevented biotin-stimulated glucokinase mRNA increase. Biotin treatment increased islet ATP content (control: 4.68+/-0.28; biotin treated: 6.62+/-0.26 pmol/islet) at 30 min. Inhibition of PKG activity suppressed the effects of biotin on ATP content. Insulin antibodies or inhibitors of phosphoinositol-3-kinase/Akt insulin signalling pathway prevented biotin-induced glucokinase expression. The nucleotide 8-Br-cGMP mimicked the biotin effects. We propose that the induction of pancreatic glucokinase mRNA by biotin involves guanylate cyclase and PKG activation, which leads to an increase in ATP content. This induces insulin secretion via ATP-sensitive potassium channels. Autocrine insulin, in turn, activates phosphoinositol-3-kinase/Akt signalling. Our results offer new insights into the pathways that participate in biotin-mediated gene expression.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/8-bromocyclic GMP, http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphate, http://linkedlifedata.com/resource/pubmed/chemical/Biotin, http://linkedlifedata.com/resource/pubmed/chemical/Cyclic GMP, http://linkedlifedata.com/resource/pubmed/chemical/Cyclic GMP-Dependent Protein Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Glucokinase, http://linkedlifedata.com/resource/pubmed/chemical/Guanylate Cyclase, http://linkedlifedata.com/resource/pubmed/chemical/Insulin, http://linkedlifedata.com/resource/pubmed/chemical/Insulin Antagonists, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol 3-Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins c-akt, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Cytoplasmic and Nuclear, http://linkedlifedata.com/resource/pubmed/chemical/soluble guanylyl cyclase
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1873-4847
pubmed:author
pubmed:copyrightInfo
(c) 2010 Elsevier Inc. All rights reserved.
pubmed:issnType
Electronic
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
606-12
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:19560332-Adenosine Triphosphate, pubmed-meshheading:19560332-Animals, pubmed-meshheading:19560332-Autocrine Communication, pubmed-meshheading:19560332-Biotin, pubmed-meshheading:19560332-Cyclic GMP, pubmed-meshheading:19560332-Cyclic GMP-Dependent Protein Kinases, pubmed-meshheading:19560332-Enzyme Inhibitors, pubmed-meshheading:19560332-Gene Expression Regulation, Enzymologic, pubmed-meshheading:19560332-Glucokinase, pubmed-meshheading:19560332-Guanylate Cyclase, pubmed-meshheading:19560332-Insulin, pubmed-meshheading:19560332-Insulin Antagonists, pubmed-meshheading:19560332-Islets of Langerhans, pubmed-meshheading:19560332-Kinetics, pubmed-meshheading:19560332-Male, pubmed-meshheading:19560332-Phosphatidylinositol 3-Kinases, pubmed-meshheading:19560332-Proto-Oncogene Proteins c-akt, pubmed-meshheading:19560332-RNA, Messenger, pubmed-meshheading:19560332-Rats, pubmed-meshheading:19560332-Rats, Wistar, pubmed-meshheading:19560332-Receptors, Cytoplasmic and Nuclear, pubmed-meshheading:19560332-Signal Transduction
pubmed:year
2010
pubmed:articleTitle
Biotin increases glucokinase expression via soluble guanylate cyclase/protein kinase G, adenosine triphosphate production and autocrine action of insulin in pancreatic rat islets.
pubmed:affiliation
Unidad de Genética de la Nutrición, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México/Instituto Nacional de Pediatría, Mexico City, C.P. 04530, Mexico.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't