An expression system of channelrhodopsin-2 driven by a minimal Arc/Arg3.1 promoter and Tet system was developed in human neuroblastoma cells.

Advances in neuroscience have relied on the development of techniques that examine neuronal cell activities. One major challenge involves the limitations in labeling and controlling neuronal activities relating to the cell's activation state. In this study, the modified human codon-optimized channelrhodopsin-2 photoreceptor hChR2(C128S) was integrated into function with inducible gene expression methods and materials: the Tet system and the highly efficient minimum promoter of Arc/Arg3.1. The system successfully expressed the target fusion gene exclusively in activated SH-SY5Y human neuroblastoma cells while maintaining the essential characteristics of ChR2. The expression of the channelrhodopsin construct was observed, while the expression duration was refined by treatment with doxycycline. The optogenetic construct here tested the application of the minimum Arc/Arg3.1 promoter, an advanced immediate-early gene promoter, for the expression of the channelrhodopsin gene. Along with its noninvasive nature, this expression system promises to serve dual functions as a cell activity indicator and cell actuator, creating the possibility for researchers to precisely label cells according to their activation state and control the activities of specific neuronal cell populations.

Expression of nano-ferritin in neuronal cells encompassed by minimal Arc promoter system.

Genetic engineering for neuronal cell activity labeling and neuronal cell activity modulation are invaluable for elucidating the underlying characteristics of the brain and neurons. In this study, ferritin fusion protein (FFP) was combined with Tet expression construct under a modified immediate-early gene (IEG) Arc/Arg3.1 promoter so-called SARE-ArcMin. This expression system is a neuronal activity-dependent expression module for nano-ferritin, a radio/magnetic wave-sensitive protein well-accepted as a potential recombinant neuronal actuator. The system was characterized in transcriptional and translational levels in human neuroblastoma SH-SY5Y cells. The mRNA and protein expression levels of nano-ferritin were significant in the activated neurons suggesting that the activity dependent expression patterns of the ferritin also acted as a neuronal cell activation indicator. The system sufficed the need for precise neuronal cell activity specific expression and demonstrated a platform that suggested the use of the nano-ferritin for the study of neuronal cells.