Linked Life Data

17563067

Source:http://linkedlifedata.com/resource/pubmed/id/17563067

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2007-8-29
pubmed:abstractText
Inadequate pancreatic beta-cell mass resulting from excessive beta-cell apoptosis is a key defect in type 1 and type 2 diabetes. Caspases are the major molecules involved in apoptosis; however, in vivo roles of specific caspases in diabetes are unclear. The purpose of this study is to examine the role of Caspase (Casp)8 in beta-cells in vivo. Using the Cre-loxP system, mice lacking Casp8 in beta-cells (RIPcre(+)Casp8(fl/fl) mice) were generated to address the role of Casp8 in beta-cells in physiological and diabetes models. We show that islets isolated from RIPcre(+)Casp8(fl/fl) mice were protected from Fas ligand (FasL)-and ceramide-induced cell death. Furthermore, RIPcre(+)Casp8(fl/fl) mice were protected from in vivo models of type 1 and type 2 diabetes. In addition to being the central mediator of apoptosis in diabetes models, we show that Casp8 is critical for maintenance of beta-cell mass under physiological conditions. With aging, RIPcre(+)Casp8(fl/fl) mice gradually develop hyperglycemia and a concomitant decline in beta-cell mass. Their islets display decreased expression of molecules involved in insulin/IGF-I signaling and show decreased pancreatic duodenal homeobox-1 and cAMP response element binding protein expression. At the level of individual islets, we observed increased insulin secretory capacity associated with increased expression of exocytotic proteins. Our results show distinct context-specific roles of Casp8 in physiological and disease states; Casp8 is essential for beta-cell apoptosis in type 1 and type 2 diabetes models and in regulating beta-cell mass and insulin secretion under physiological conditions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1939-327X
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
56
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2302-11
pubmed:dateRevised
2007-10-29
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Distinct in vivo roles of caspase-8 in beta-cells in physiological and diabetes models.
pubmed:affiliation
Department of Medical Biophysics, Ontario Cancer Institute, and the University of Toronto, Toronto, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't