Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2009-1-23
pubmed:abstractText
FOXL2 is a forkhead transcription factor, essential for ovarian function, whose mutations are responsible for the blepharophimosis syndrome, characterized by craniofacial defects, often associated with premature ovarian failure. Here, we show that cell stress upregulates FOXL2 expression in an ovarian granulosa cell model. Increased FOXL2 transcription might be mediated at least partly by self-activation. Moreover, using 2D-western blot, we show that the response of FOXL2 to stress correlates with a dramatic remodeling of its post-translational modification profile. Upon oxidative stress, we observe an increased recruitment of FOXL2 to several stress-response promoters, notably that of the mitochondrial manganese superoxide dismutase (MnSOD). Using several reporter systems, we show that FOXL2 transactivation is enhanced in this context. Models predict that gene upregulation in response to a signal should eventually be counterbalanced to restore the initial steady state. In line with this, we find that FOXL2 activity is repressed by the SIRT1 deacetylase. Interestingly, we demonstrate that SIRT1 transcription is, in turn, directly upregulated by FOXL2, which closes a negative-feedback loop. The regulatory relationship between FOXL2 and SIRT1 prompted us the test action of nicotinamide, an inhibitor of sirtuins, on FoxL2 expression/activity. According to our expectations, nicotinamide treatment increases FoxL2 transcription. Finally, we show that 11 disease-causing mutations in the ORF of FOXL2 induce aberrant regulation of FOXL2 and/or regulation of the FOXL2 stress-response target gene MnSOD. Taken together, our results establish that FOXL2 is an actor of the stress response and provide new insights into the pathogenic consequences of FOXL2 mutations.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1460-2083
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
632-44
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Positive and negative feedback regulates the transcription factor FOXL2 in response to cell stress: evidence for a regulatory imbalance induced by disease-causing mutations.
pubmed:affiliation
INSERM U567, Team 21, Department of Genetics and Development, Paris, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't