MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Nguyen, K.-T. T.
Right arrow Articles by Woo, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nguyen, K.-T. T.
Right arrow Articles by Woo, M.
Molecular and Cellular Biology, June 2006, p. 4511-4518, Vol. 26, No. 12
0270-7306/06/$08.00+0     doi:10.1128/MCB.00238-06
Copyright © 2006, American Society for Microbiology. All Rights Reserved.

Essential Role of Pten in Body Size Determination and Pancreatic ß-Cell Homeostasis In Vivo

Kinh-Tung T. Nguyen,1 Panteha Tajmir,1 Chia Hung Lin,1 Nicole Liadis,1 Xu-Dong Zhu,1 Mohammed Eweida,1 Gunce Tolasa-Karaman,2 Fang Cai,2 Rennian Wang,3 Tadahiro Kitamura,4 Denise D. Belsham,2 Michael B. Wheeler,2 Akira Suzuki,5 Tak W. Mak,1,6 and Minna Woo1,7*

Department of Medicine, Medical Biophysics, Institute of Medical Science, Ontario Cancer Institute, University of Toronto, Toronto, Ontario, Canada,1 Department of Physiology, University of Toronto, Toronto, Ontario, Canada,2 Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada,3 Department of Medicine, Columbia University, New York, New York,4 Department of Molecular Biology, Akita University School of Medicine, Akita, Japan,5 The Advanced Medical Discovery Institute and The Campbell Family Institute for Breast Cancer Research, Toronto, Ontario, Canada,6 Department of Medicine, St. Michael's Hospital, Toronto, Ontario, Canada7

Received 8 February 2006/ Returned for modification 21 March 2006/ Accepted 30 March 2006

PTEN (phosphatase with tensin homology) is a potent negative regulator of phosphoinositide 3-kinase (PI3K)/Akt signaling, an evolutionarily conserved pathway that signals downstream of growth factors, including insulin and insulin-like growth factor 1. In lower organisms, this pathway participates in fuel metabolism and body size regulation and insulin-like proteins are produced primarily by neuronal structures, whereas in mammals, the major source of insulin is the pancreatic ß cells. Recently, rodent insulin transcription was also shown in the brain, particularly the hypothalamus. The specific regulatory elements of the PI3K pathway in these insulin-expressing tissues that contribute to growth and metabolism in higher organisms are unknown. Here, we report PTEN as a critical determinant of body size and glucose metabolism when targeting is driven by the rat insulin promoter in mice. The partial deletion of PTEN in the hypothalamus resulted in significant whole-body growth restriction and increased insulin sensitivity. Efficient PTEN deletion in ß cells led to increased islet mass without compromise of ß-cell function. Parallel enhancement in PI3K signaling was found in PTEN-deficient hypothalamus and ß cells. Together, we have shown that PTEN in insulin-transcribing cells may play an integrative role in regulating growth and metabolism in vivo.


* Corresponding author. Mailing address: Princess Margaret Hospital, 8th Floor, Room 8-113, Toronto, Ontario, Canada M5G 2M9. Phone: (416) 946-4501, ext. 3971. Fax: (416) 946-2086. E-mail: mwoo{at}uhnres.utoronto.ca.


Molecular and Cellular Biology, June 2006, p. 4511-4518, Vol. 26, No. 12
0270-7306/06/$08.00+0     doi:10.1128/MCB.00238-06
Copyright © 2006, American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2006 by the American Society for Microbiology. All rights reserved.