Abstract
Pancreatic β cells play a central role in maintaining glucose homeostasis because they secrete insulin in response to increased level of blood glucose; failure of this capacity constitutes a major component of the pathogenesis of diabetes. The identification of key regulators of pancreatic β-cell differentiation is relevant for the overall understanding of this process and for future experiments aimed at regenerating insulin-producing β cells from pancreatic or embryonic stem cells. Several studies using transgenic or knockout mice have established that the development and function of pancreatic β cells are controlled by several genes encoding specific transcription factors. By inactivating the homeobox gene Pax4, we previously demonstrated that its function is required for the formation of mature insulin-producing cells. Here, we show that during pancreas ontogeny, Pax4 is expressed in differentiating endocrine cells, including β cells. Pax4 activity appears essential for appropriate initiation of β-cell differentiation because loss of Pax4 prevents the expression of Pdx1, HB9 and insulin in β-cell precursors. This role of Pax4 appears to be accomplished via its genetic interaction with another homeobox gene, Nkx2.2.
Original language | English (US) |
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Pages (from-to) | 178-189 |
Number of pages | 12 |
Journal | Developmental Biology |
Volume | 266 |
Issue number | 1 |
DOIs | |
State | Published - Feb 1 2004 |
Funding
We thank S. Kalloway and S. Holloway for excellent technical assistance, A. Demirkan for help with immunohistochemistry, G. Oliver for critical reading of this manuscript, K.G. Murti and K. Barnes for help with confocal laser-scanning microscopy, and A. McArthur for editing the manuscript. We also thank the following people for generously providing reagents: M. German, P. Gruss, T. Jessell, J. Kehrl, D. Mastick, P. Serup, and C.V. Wright. This work was supported in part by grant VUMC9183 (B.S.-P.) from the Beta Cell Biology Consortium (Vanderbilt University, Nashville, TN), by Cancer Center Support CA 21765 from the National Cancer Institute, and by the American Lebanese Syrian Associated Charities (ALSAC).
Keywords
- Mouse
- Nkx2.2
- Pancreas
- Pax4
- Pax6
- β-cell differentiation
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology
- Developmental Biology