PDX-1/VP16 Fusion Protein, Together With NeuroD or Ngn3, Markedly Induces Insulin Gene Transcription and Ameliorates Glucose Tolerance
- Hideaki Kaneto,
- Yoshihisa Nakatani,
- Takeshi Miyatsuka,
- Taka-aki Matsuoka,
- Munehide Matsuhisa,
- Masatsugu Hori and
- Yoshimitsu Yamasaki
- Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, Osaka, Japan
- Address correspondence and reprint requests to Hideaki Kaneto, MD, PhD, Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan. E-mail: kaneto{at}medone.med.osaka-u.ac.jp
Abstract
Diabetes is the most prevalent and serious metabolic disease, and the number of diabetic patients worldwide is increasing. The reduction of insulin biosynthesis in pancreatic β-cells is closely associated with the onset and progression of diabetes, and thus it is important to search for ways to induce insulin-producing cells in non−β-cells. In this study, we showed that a modified form of the pancreatic and duodenal homeobox factor 1 (PDX-1) carrying the VP16 transcriptional activation domain (PDX-1/VP16) markedly increases insulin biosynthesis and induces various pancreas-related factors in the liver, especially in the presence of NeuroD or neurogenin 3 (Ngn3). Furthermore, in streptozotocin-induced diabetic mice, PDX-1/VP16 overexpression, together with NeuroD or Ngn3, drastically ameliorated glucose tolerance. Thus PDX-1/VP16 expression, together with NeuroD or Ngn3, markedly induces insulin gene transcription and ameliorates glucose tolerance. This approach warrants further investigation and may have utility in the treatment of diabetes.
- ABC, avidin-biotin complex
- Ad, adenovirus
- ALT, alanine aminotransferase
- AST, aspartic acid aminotransferase
- bHLH, basic helix-loop-helix
- DAB, 3, 3′-diaminobenzidine tetrahydrochloride
- GFP, green fluorescent protein
- MODY, maturity-onset diabetes of the young
- Ngn3, neurogenin 3
- PDX-1, pancreatic and duodenal homeobox factor 1
- PFU, plaque forming unit
- STZ, streptozotocin
- TBS, Tris-buffered saline
Footnotes
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H.K. and Y.N. contributed equally to this work.
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- Accepted January 7, 2005.
- Received July 28, 2004.
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