A red/far-red light-responsive bi-stable toggle switch to control gene expression in mammalian cells

Abstract

Growth and differentiation of multicellular systems is orchestrated by spatially restricted gene expression programs in specialized subpopulations. The targeted manipulation of such processes by synthetic tools with high-spatiotemporal resolution could, therefore, enable a deepened understanding of developmental processes and open new opportunities in tissue engineering. Here, we describe the first red/far-red light-triggered gene switch for mammalian cells for achieving gene expression control in time and space. We show that the system can reversibly be toggled between stable on- and off-states using short light pulses at 660 or 740 nm. Red light-induced gene expression was shown to correlate with the applied photon number and was compatible with different mammalian cell lines, including human primary cells. The light-induced expression kinetics were quantitatively analyzed by a mathematical model. We apply the system for the spatially controlled engineering of angiogenesis in chicken embryos. The system’s performance combined with cell- and tissue-compatible regulating red light will enable unprecedented spatiotemporally controlled molecular interventions in mammalian cells, tissues and organisms.

Algal photoreceptors: in vivo functions and potential applications

“…A light-switchable gene promoter system should also be mentioned, which was constructed using an Arabidopsis phytochrome; this system allows for reversible control of gene expression with red and far-red light (Shimizu-Sato et al 2002). The far-red reversibility of phytochromes was also used for development of a light-switchable proteinprotein interaction system for spatiotemporal control of cell signaling (Levskaya et al 2009) and for the design of a red/far-red light-responsive bistable toggle switch to control molecular interventions in mammalian cells, tissues and organisms (Müller et al 2013). …”

Engineering adenylate cyclases regulated by near-infrared window light

“…This results in a 2-to 10-fold gain in the penetration depth of light through mammalian tissues (7,10). Up to now, bacteriophytochrome engineering for optogenetic applications has lagged behind the engineering of photoreceptors of other types (4,5), including engineering of plant phytochromes (15,16). The major obstacle to bacteriophytochrome engineering has been the lack of understanding of the mechanisms through which light-induced conformational changes are transduced to regulate output activities (12)(13)(14)17).…”

Engineering synthetic optogenetic networks for biomedical applications

“…Nowadays, synthetic biologists have designed complex artificial gene circuits assembled into biosensing devices to monitor cellular behavior, which have promising therapeutic applications [3,109,110]. Compared to chemical or microwave systems, optogenetic tools triggered by specific wavelengths of light offer unprecedented spatiotemporal precision without the addition of chemical inducers that might perturb the system under investigation [95,111]. Consequently, the field of optogenetics has experienced a big upsurge over the last few years, and have begun to revolutionize biomedical research.…”

“…Recently, optogenetics has turned early ideas into a powerful paradigm for cell biology [28,29]. In the most recent studies, several light-responsive gene expression systems designed with the engineering-driven approaches of modularization, rationalization and modeling have been created to monitor and control mammalian cellular activities with the unmatched precision of light stimulation [30][31][32][33][34].…”