Bioluminescence‐driven optogenetic activation of transplanted neural precursor cells improves motor deficits in a Parkinson's disease mouse model

Abstract

The need to develop efficient therapies for neurodegenerative diseases is urgent, especially given the increasing percentages of the population living longer, with increasing chances of being afflicted with conditions like Parkinson's disease (PD). A promising curative approach toward PD and other neurodegenerative diseases is the transplantation of stem cells to halt and potentially reverse neuronal degeneration. However, stem cell therapy does not consistently lead to improvement for patients. Using remote stimulation to optogenetically activate transplanted cells, we attempted to improve behavioral outcomes of stem cell transplantation. We generated a neuronal precursor cell line expressing luminopsin 3 (LMO3), a luciferase-channelrhodopsin fusion protein, which responds to the luciferase substrate coelenterazine (CTZ) with emission of blue light that in turn activates the opsin. Neuronal precursor cells were injected bilaterally into the striatum of homozygous aphakia mice, which carry a spontaneous mutation leading to lack of dopaminergic neurons and symptoms of PD. Following transplantation, the cells were stimulated over a period of 10 days by intraventricular injections of CTZ. Mice receiving CTZ demonstrated significantly improved motor skills in a rotarod test compared to mice receiving vehicle. Thus, bioluminescent optogenetic stimulation of transplanted neuronal precursor cells shows promising effects in improving locomotor behavior in the aphakia PD mouse model and encourages further studies to elucidate the mechanisms and long-term outcomes of these beneficial effects.

Selective Postnatal Excitation of Neocortical Pyramidal Neurons Results in Distinctive Behavioral and Circuit Deficits in Adulthood

“…To accommodate the need for non-invasive stimulation of genetically targeted neural circuits in a postnatally growing brain and temporally precise interrogation of the same circuits in the same animal as an adult, we employed bioluminescent optogenetics (BL-OG) (Berglund et al, 2013(Berglund et al, , 2016Park et al, 2017;Song et al, 2018;Zenchak et al, 2018;Gomez-Ramirez et al, 2019;Yu et al, 2019). Here an optogenetic element can be activated either by light emitted from a tethered luciferase oxidizing a small molecule substrate, or by light emitted from physical sources, such as LEDs or lasers ( Figure 1A).…”

The BioLuminescent‐OptoGenetic in vivo response to coelenterazine is proportional, sensitive, and specific in neocortex

“…BioLuminescent OptoGenetics (“BL‐OG”) is an emerging dual strategy that provides both optogenetic and chemogenetic capabilities. In this approach, binding of an oxidative enzyme (luciferase) to a small light‐emitting molecule (luciferin) drives bioluminescence that, in turn, regulates a neighboring opsin (Berglund, Birkner, Augustine, & Hochgeschwender, ; Berglund, Clissold, et al, ; Berglund, Fernandez, Gutekunst, Hochgeschwender, & Gross, ; Berglund, Tung, et al, ; Birkner, Berglund, Klein, Augustine, & Hochgeschwender, ; Park et al, ; Prakash, Medendorp, & Hochgeschwender, ; Tung et al, ; Tung, Shiu, Ding, & Gross, ; Zenchak et al, ). To ensure proximity of the bioluminescent reaction to the recipient opsin, the luminopsin (LMO) construct was invented, in which a luciferase is linked to the optogenetic element by a short 15 amino acids linker (Berglund, Tung, et al, ).…”

The BioLuminescent-OptoGenetic in vivo Response to Coelenterazine is Proportional, Sensitive and Specific in Neocortex

“…BioLuminescent OptoGenetics ('BL-OG') is an emerging dual strategy that provides both optogenetic and chemogenetic capabilities. In this approach, binding of an oxidative enzyme (luciferase) to a small light-emitting molecule (luciferin) drives bioluminescence that, in turn, regulates a neighboring opsin (Berglund et al, 2013;Birkner et al, 2014;Tung et al, 2015;Berglund et al, 2016b;Berglund et al, 2016a;Park et al, 2017;Prakash et al, 2018;Tung et al, 2018;Zenchak et al, 2018;Berglund et al, 2019). To ensure proximity of the bioluminescent reaction to the recipient opsin, the luminopsin (LMO) construct was invented, in which a luciferase is linked to the optogenetic element by a short 15 amino acids linker (Berglund et al, 2016a).…”

“…Here, we systematically tested the relationship between BL-OG neural modulation and photon production, and the possibility that non-specific components of its bioluminescent reaction modulate neuronal spiking. To this end, we expressed LMO3 in mice, a BL-OG construct previously demonstrated to robustly activate neurons (Berglund et al, 2016b;Berglund et al, 2016a;Prakash et al, 2018), and drive behavioral responses when activated by CTZ (Berglund et al, 2016a;Zenchak et al, 2018). We tested whether the neural response in LMO3expressing mice was proportional to CTZ dose and photon production.…”