Biology subjects

Pomeranz, L. E.

Publications and source records attributed to Pomeranz, L. E..

3 recordsLinked to original sources

bioRxiv2025

Non-invasive in vivo bidirectional magnetogenetic modulation of pain circuits.

Primary nociceptors in the dorsal root ganglion (DRG) receive sensory information from discrete parts of the body and are responsible for initiating signaling events that in supraspinal regions will be interpreted as physiological or pathological pain. Genetic, pharmacologic and electric neuromodulation of nociceptor activity in freely moving non-transgenic animals has been shown to be challenging due to many factors including the immunogenicity of non-mammalian proteins, procedure invasiveness and poor temporal precision. Here, we introduce a magnetogenetic strategy that enables remote bidirectional regulation of nociceptor activity. Magnetogenetics utilizes a source of direct magnetic field (DMF) to control neuronal activity in cells that express an anti-ferritin nanobody-TRPV1 receptor fusion protein (Nb-Ft-TRPV1). In our study, AAV2retro-mediated delivery of an excitatory Nb-Ft-TRPV1 construct into the sciatic nerve of wild-type mice resulted in stable long-term transgene expression accompanied by significant reduction of mechanical withdrawal thresholds during DMF exposure, place aversion of the DMF zone and activity changes in the anterior cingulate (ACC) nucleus. Conversely, delivery of an inhibitory variant of the Nb-Ft-TRPV1 construct, engineered to gate chloride ions in response to DMF, led to reversed behavioral manifestations of mechanical allodynia and showed place preference for the DMF zone, suggestive of functional pain relief. Changes in DRG activity were confirmed by post-mortem levels, immediately following DMF exposure, of the activity-induced gene cfos, which increased with the excitatory construct in normal mice and decreased with the inhibitory construct in pain models Our study demonstrates that magnetogenetic channels can achieve long-term expression in the periphery without losing functionality, providing a stable gene therapy system for non-invasive, magnetic field regulation of pain-related neurons for research and potential clinical applications.

neuroscience↗

bioRxiv2023

Bidirectional Regulation of Motor Circuits Using Magnetogenetic Gene Therapy

Here we report a novel suite of magnetogenetic tools, based on a single anti-ferritin nanobody-TRPV1 receptor fusion protein, which regulated neuronal activity when exposed to magnetic fields. AAV-mediated delivery of a floxed nanobody-TRPV1 into the striatum of adenosine 2a receptor-cre driver mice resulted in motor freezing when placed in an MRI or adjacent to a transcranial magnetic stimulation (TMS) device. Functional imaging and fiber photometry both confirmed activation of the target region in response to the magnetic fields. Expression of the same construct in the striatum of wild-type mice along with a second injection of an AAVretro expressing cre into the globus pallidus led to similar circuit specificity and motor responses. Finally, a mutation was generated to gate chloride and inhibit neuronal activity. Expression of this variant in subthalamic nucleus in PitX2-cre parkinsonian mice resulted in reduced local c-fos expression and motor rotational behavior. These data demonstrate that magnetogenetic constructs can bidirectionally regulate activity of specific neuronal circuits non-invasively in-vivo using clinically available devices. TeaserA novel magnetogenetics toolbox to regulate neural circuits in-vivo.

neuroscience↗

bioRxiv2023

Magnetogenetic cell activation using endogenous ferritin

The ability to precisely control the activity of defined cell populations enables studies of their physiological roles and may provide therapeutic applications. While prior studies have shown that magnetic activation of ferritin-tagged ion channels allows cell-specific modulation of cellular activity, the large size of the constructs made the use of adeno-associated virus, AAV, the vector of choice for gene therapy, impractical. In addition, simple means for generating magnetic fields of sufficient strength have been lacking. Toward these ends, we first generated a novel anti-ferritin nanobody that when fused to transient receptor potential cation channel subfamily V member 1, TRPV1, enables direct binding of the channel to endogenous ferritin in mouse and human cells. This smaller construct can be delivered in a single AAV and we validated that it robustly enables magnetically induced cell activation in vitro. In parallel, we developed a simple benchtop electromagnet capable of gating the nanobody-tagged channel in vivo. Finally, we showed that delivering these new constructs by AAV to pancreatic beta cells in combination with the benchtop magnetic field delivery stimulates glucose-stimulated insulin release to improve glucose tolerance in mice in vivo. Together, the novel anti-ferritin nanobody, nanobody-TRPV1 construct and new hardware advance the utility of magnetogenetics in animals and potentially humans.

bioengineering↗