Self-adjusting synthetic gene circuit for correcting insulin resistance

Sophisticated genetic devices can be assembled to reprogram mammalian cell activities using tools from synthetic biology. Here, we demonstrate that a self-adjusting synthetic gene circuit can be designed to sense and reverse the insulin-resistance syndrome in different mouse models. By functionally rewiring the mitogen-activated protein kinase (MAPK) signalling pathway to produce MAPK-mediated activation of a hybrid transcription factor consisting of the tetracycline repressor, TetR, fused to the human ELK1-derived transactivation domain (TetR-Elk1), we assembled a synthetic insulin-sensitive transcriptioncontrol device that self-sufficiently distinguished between physiological and increased blood insulin levels and correspondingly fine-tuned the reversible expression of therapeutic transgenes from synthetic TetR-ELK1-specific promoters. In acute experimental hyperinsulinaemia, the synthetic insulin-sensing designer circuit reversed the insulin-resistance syndrome by coordinating expression of the insulin-sensitizing compound adiponectin. Engineering synthetic gene circuits to sense pathologic markers and coordinate the expression of therapeutic transgenes may provide opportunities for future gene-and cell-based treatments of multifactorial metabolic disorders.