Linked Life Data

8530582

Source:http://linkedlifedata.com/resource/pubmed/id/8530582

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1996-1-31
pubmed:abstractText
Most patients with deletion of the distal long arm of chromosome 15 have intrauterine growth retardation and postnatal growth deficiency in addition to developmental abnormalities. It has been proposed that the absence of one copy of the insulin-like growth factor I (IGF-I) receptor gene may play a role in the growth deficiency seen in this syndrome. To address this question we examined IGF-I receptor expression and function in fibroblasts from two patients with deletion of the distal long arm of chromosome 15 (15q26.1-->qter). Quantitative Southern blot analysis of the IGF-I receptor gene was performed on HindIII digests of fibroblast DNA. Radioactivity in the 1.7-kilobase receptor fragment in the two patients was 55% and 51% of the values in controls, consistent with the absence of one copy of the IGF-I receptor gene. IGF-I receptor messenger ribonucleic acid levels were quantitated by a solution hybridization/nuclease protection assay. Receptor messenger ribonucleic acid levels in the two patients were 45% and 52% of the values in controls. Northern blotting demonstrated normal size IGF-I receptor transcripts and affinity crosslinking of [125I]IGF-I to Triton X-100-solubilized fibroblasts demonstrated a normal size receptor in the patients. Analysis of placental membranes prepared from one patient revealed no difference in [125I]IGF-I binding. In the patients' fibroblasts, however, binding of [125I]long [R3]-IGF-I to the IGF-I receptor was significantly reduced, as assessed by the amount of radioactivity competed by the monoclonal antibody alpha IR-3 or insulin and Scatchard analysis of binding data. To assess IGF-I receptor function, stimulation of [alpha-1-14C]-methylaminoisobutyric acid transport and stimulation of [methyl-3H]thymidine incorporation into DNA by a full range of IGF-I concentrations was examined in patient and control fibroblasts. There was a significant decrease in the maximal response to IGF-I in both assays for one of the two patients when data were expressed as fold response over the basal value. However, there was no evidence for impairment of response to IGF-I in either patient's fibroblasts when data were expressed as net stimulation (maximal response minus basal). In conclusion, although IGF-I receptor expression was decreased in fibroblasts from two patients with deletion of the distal long arm of chromosome 15, we were unable to provide conclusive evidence for impairment of the biological response to IGF-I.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-972X
pubmed:author
pubmed:issnType
Print
pubmed:volume
80
pubmed:owner
NLM
pubmed:authorsComplete
N
pubmed:pagination
3447-57
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Insulin-like growth factor I receptor expression and function in fibroblasts from two patients with deletion of the distal long arm of chromosome 15.
pubmed:affiliation
Metabolism Branch, National Cancer Institute, National Institutes of Health Bethesda, Maryland 20892, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Case Reports, Research Support, Non-U.S. Gov't