Mifepristone-inducible transgene expression in neural progenitor cells in vitro and in vivo

Abstract

Numerous gene and cell therapy strategies are being developed for the treatment of neurodegenerative disorders. Many of these strategies use constitutive expression of therapeutic transgenic proteins, and although functional in animal models of disease, this method is less likely to provide adequate flexibility for delivering therapy to humans. Ligand-inducible gene expression systems may be more appropriate for these conditions, especially within the central nervous system (CNS). Mifepristone’s ability to cross the blood–brain barrier makes it an especially attractive ligand for this purpose. We describe the production of a mifepristone-inducible vector system for regulated expression of transgenes within the CNS. Our inducible system used a lentivirus-based vector platform for the ex vivo production of mifepristone-inducible murine neural progenitor cells that express our transgenes of interest. These cells were processed through a series of selection steps to ensure that the cells exhibited appropriate transgene expression in a dose-dependent and temporally controlled manner with minimal background activity. Inducible cells were then transplanted into the brains of rodents, where they exhibited appropriate mifepristone-inducible expression. These studies detail a strategy for regulated expression in the CNS for use in the development of safe and efficient gene therapy for neurological disorders.

A synthetic BRET-based optogenetic device for pulsatile transgene expression enabling glucose homeostasis in mice

“…Previously, chemically regulated gene expression systems have been widely used for the temporal control of gene expression in numerous biological studies [8][9][10] . However, gene expression from these systems continues for quite a long time once the inducers are presented, as it takes time for these chemical inducers to be degraded or metabolized 11 .…”

Externally-Controlled Systems for Immunotherapy: From Bench to Bedside

“…Different GS system has been developed for inducible gene therapy approaches to fight liver cancer ( 68 – 70 ), as well as for the treatment of neurological diseases ( 71 , 72 ).…”

Spatiotemporally-controlled transgene expression in hydroxyapatite-fibrin composite scaffolds using high intensity focused ultrasound

“…With a liganddependent system, gene expression is temporally controlled based on the timing of ligand administration, while heat shock inducible switches can be activated by hyperthermic water baths. In both cases, good temporal control of factor delivery is achieved, but spatial control is not possible [8][9][10][11]. Optogenetic [12] and photothermal [13] techniques have also been shown to provide tight spatiotemporal control of gene expression regulated by light or heat shock, respectively; although activation is restricted to superficial tissues due to the relatively limited penetration of light.…”