Exp Mol Med.  2006 Aug;38(4):385-392.

Development of ligand-dependent regulatory system and its application to gene therapy of insulin-dependent diabetes mellitus

• Kim JM
• Kim SJ
• Lee HC
• Kim KS

Abstract

To develop an inducible expression system, the enhanced artificial nuclear receptors and target reporters were constructed. Artificial nuclear receptors were generated by fusing three domains, consisting of DNA-binding domain (DBD) of GAL4, ligand binding domain (LBD) of progesterone or estrogen receptor, and activation domain (AD) of VP16, sterol regulatory element binding protein (SREBP)-1a, or SREBP-2. The activation domain of SREBP-1a showed most potent transcriptional activity. The maximal level of target reporter gene expression was extremely elevated by the usage of ATP citrate-lyase (ACL) minimal promoter -60/+67 in place of artificial TATA promoter, while the SV40 enhancer severely increased the basal transcription in the absence of ligand. The induction system, developed in the present study, was applied to cell therapy, resulting in successful induction of single-chain insulin analogue (SIA) gene expression to correct the hyperglycemia in diabetic animals. By means of subcutaneous cell therapy, the SIA gene expression rapidly occurred after the local topical application of ligand. These results suggest that our system represents a powerful tool for transcriptional regulation of target gene that can be used for diverse applications, ranging from basic research to gene therapy.

Keyword

apoptosis; lysophosphatidylcholines; neu-rites; PC12 cells; phospholipase D2

MeSH Terms

Transfection
Trans-Activation (Genetics)
Receptors, Cytoplasmic and Nuclear/genetics
Mice, Inbred BALB C
Mice
Male
*Ligands
Genetic Vectors/*chemical synthesis
Genes, Reporter
Gene Therapy/*methods
*Gene Expression Regulation
Diabetes Mellitus, Type 1/*therapy
Diabetes Mellitus, Experimental/blood/*therapy
Blood Glucose/analysis
Animals