Near-Infrared Light-Directed RNAi Using a Photosensitive Carrier Molecule

Controlled activation of small RNAs, such as small interfering RNA, in cells is very useful for various biological applications. Light is an effective inducer of controlled activation; in particular, near-infrared light is favorable because it can penetrate deeper into tissues than UV or visible light. In this study, near-infrared light control of RNA interference (RNAi) was demonstrated in mammalian cells using a photosensitive RNA carrier molecule, consisting of an RNA carrier protein and a fluorochrome. The photosensitive carrier molecule was identified from six candidates, each with a different fluorochrome. Using this carrier molecule, cytosolic RNA delivery and RNAi can be triggered by near-infrared light. Cytotoxicity was not observed after photoinduction of RNAi

Red and Near-Infrared Light-Directed Cytosolic Delivery of Two Different RNAs Using Photosensitive RNA Carriers

Many cellular events are thought to be controlled by the temporal upregulation of multiple RNAs; the timing of the upregulation of these RNAs is not always the same. In this study, we first show that our light-directed intracellular RNA delivery method induced high concentrations of RNA in a short period. This effect was beneficial for the temporal control of cellular events by functional RNAs. Next, we stimulated the short-term upregulation of two different RNAs at different time points. Cytosolic delivery of a first RNA was induced by red light; thereafter, cytosolic delivery of a second RNA was induced by near-infrared light. The time difference between the introduction of the first and second RNA can be short (0.5–4 h) or long (>8 h). This strategy shows the potential for future applications of the deliberate control of time-dependent RNA concentration to guide various cellular functions by multiple RNAs