Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-4-4
pubmed:abstractText
Type 1 diabetes or insulin-dependent diabetes mellitus (IDDM) is due to autoimmune destruction of pancreatic beta-cells. Genetic susceptibility to IDDM is encoded by several loci, one of which (IDDM2) maps to a variable number of tandem repeats (VNTR) minisatellite, upstream of the insulin gene (INS). The short class I VNTR alleles (26-63 repeats) predispose to IDDM, while class III alleles (140-210 repeats) have a dominant protective effect. We have reported that, in human adult and fetal pancreas in vivo, class III alleles are associated with marginally lower INS mRNA levels than class I, suggesting transcriptional effects of the VNTR. These may be related to type 1 diabetes pathogenesis, as insulin is the only known beta-cell specific IDDM autoantigen. In search of a more plausible mechanism for the dominant effect of class III alleles, we analysed expression of insulin in human fetal thymus, a critical site for tolerance induction to self proteins. Insulin was detected in all thymus tissues examined and class III VNTR alleles were associated with 2- to 3-fold higher INS mRNA levels than class I. We therefore propose higher levels of thymic INS expression, facilitating immune tolerance induction, as a mechanism for the dominant protective effect of class III alleles.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1061-4036
pubmed:author
pubmed:issnType
Print
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
289-92
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:9054944-Abortion, Therapeutic, pubmed-meshheading:9054944-Adult, pubmed-meshheading:9054944-Alleles, pubmed-meshheading:9054944-Animals, pubmed-meshheading:9054944-Chromosome Mapping, pubmed-meshheading:9054944-DNA Primers, pubmed-meshheading:9054944-Diabetes Mellitus, Type 1, pubmed-meshheading:9054944-Disease Susceptibility, pubmed-meshheading:9054944-Female, pubmed-meshheading:9054944-Fetus, pubmed-meshheading:9054944-Gene Expression Regulation, Developmental, pubmed-meshheading:9054944-Humans, pubmed-meshheading:9054944-Immune Tolerance, pubmed-meshheading:9054944-Insulin, pubmed-meshheading:9054944-Male, pubmed-meshheading:9054944-Mice, pubmed-meshheading:9054944-Mice, Inbred C57BL, pubmed-meshheading:9054944-Minisatellite Repeats, pubmed-meshheading:9054944-Muridae, pubmed-meshheading:9054944-Polymerase Chain Reaction, pubmed-meshheading:9054944-Pregnancy, pubmed-meshheading:9054944-RNA, Messenger, pubmed-meshheading:9054944-Thymus Gland, pubmed-meshheading:9054944-Transcription, Genetic
pubmed:year
1997
pubmed:articleTitle
Insulin expression in human thymus is modulated by INS VNTR alleles at the IDDM2 locus.
pubmed:affiliation
McGill University-Montreal Children's Hospital Research Institute, Montréal, Québec, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't