Linked Life Data

15843404

Source:http://linkedlifedata.com/resource/pubmed/id/15843404

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2005-5-20
pubmed:abstractText
Lipodystrophies are a heterogeneous group of human disorders characterized by the anomalous distribution of body fat associated with insulin resistance and altered lipid metabolism. The pathogenetic mechanism of inherited lipodystrophies is not yet clear; at the molecular level they have been linked to mutations of lamin A/C, peroxisome proliferator-activated receptor (PPARgamma) and other seemingly unrelated proteins. In this study, we examined lamin A/C processing in three laminopathies characterized by lipodystrophic phenotypes: Dunnigan type familial partial lipodystrophy, mandibuloacral dysplasia and atypical Werner's syndrome. We found that the lamin A precursor was specifically accumulated in lipodystrophy cells. Pre-lamin A was located at the nuclear envelope and co-localized with the adipocyte transcription factor sterol regulatory element binding protein 1 (SREBP1). Using co-immunoprecipitation experiments, we obtained the first demonstration of an in vivo interaction between SREBP1 and pre-lamin A. Binding of SREBP1 to the lamin A precursor was detected in patient fibroblasts as well as in control fibroblasts forced to accumulate pre-lamin A by farnesylation inhibitors. In contrast, SREBP1 did not interact in vivo with mature lamin A or C in cultured fibroblasts. To gain insights into the effect of pre-lamin A accumulation in adipose tissue, we inhibited lamin A precursor processing in 3T3-L1 pre-adipocytes. Our results show that pre-lamin A sequesters SREBP1 at the nuclear rim, thus decreasing the pool of active SREBP1 that normally activates PPARgamma and causing impairment of pre-adipocyte differentiation. This defect can be rescued by treatment with troglitazone, a known PPARgamma ligand activating the adipogenic program.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0964-6906
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1489-502
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Altered pre-lamin A processing is a common mechanism leading to lipodystrophy.
pubmed:affiliation
ITOI, CNR, Unit of Bologna, c/o IOR, Bologna, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't