Molecular Imaging for Detection of Synthetic Biology Circuits, Oscillators and Toggle Switches in Regenerative Medicine

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Harnessing the power of therapeutic stem cells holds great promises for the discovery of new treatments to many chronic and uncured diseases. Despite few milestone studies, the overall success has been limited. Studies around the world showed that it is safe to use such cells, however, those cells must be first engineered so they can preformed the desired task, similar to the way that electronic component are engineered for preforming computational tasks. In synthetic biology, much like in electronics, we can use biological components to build a circuit that can preform a very specific function. Instead of using electronic parts we can used biological parts or “bio-parts” that interact with the outmost specificity one with another. Here we seek to use three “bio-parts” that will be sufficient to control stem cell activity and fate in situ. This is extremely important because to date, there is no way to remote control cells, inside the body, without invasively penetrating the body tissue. To that end, we will construct a biological circuit inside stem cells. For the “switch” we will use a novel protein, encoded by a gene that was discovered in our lab. This novel protein can sense and respond to an external electromagnetic field, i.e., can be switch on and off by a static magnet or an electronic device. Once it is activated it lead to release of calcium. A calcium sensitive promoter is used as an “amplifier”. The third bio-part is a reporter gene that we will use for visualization of the activity and in the future can be replace by a therapeutic gene. In the first aim we will establish a cell culture system that can express all the bio-parts of the “device” in stem cells. Specifically in iPSCs-derived neurons and adipocytes derived stem cells (ADSCs). In the second Aim we will test two modes of cell activation. The first one is with ferromagnetic (not to be confused with paramagnetic) nanoparticles (FMNPs). Those FMNPs will be functionalized with ligands that bind to the stem cell membrane. This will result in continues activation (“off”→”on”) of genes. This is relevant to cases where we need to induce cell differentiation either to specific linage or even to reverse pluripotency. The second mode of activation is oscillations, induced by an electromagnet, that can we alternately switch on and off for brief time periods. This can create an oscillatory pattern that can result in cyclic production of metabolites, hormones and drugs. This is relevant, for example, for disease such as diabetes where it can replace the daily insulin injection or in cancer where are controlled drug release is required. In the third Aim, we will transplant the bioengineered stem cells in the rodent brain and will monitor both the Toggle switch and the oscillator in vivo using a reporter gene engineered for both MRI and PET. Thus, this innovative study is a unique approach to transition synthetic biology strategies from microorganism to mammalian system with clear path for clinical translation.