PT  - JOURNAL ARTICLE
AU  - Ernst, Patrick
AU  - Xu, Ningning
AU  - Qu, Jing
AU  - Chen, Herbert
AU  - Goldberg, Matthew S.
AU  - Darley-Usmar, Victor
AU  - Zhang, Jianyi J.
AU  - O’Rourke, Brian
AU  - Liu, Xiaoguang
AU  - Zhou, Lufang
TI  - Precisely control mitochondria with light to manipulate cell fate decision
AID  - 10.1101/469668
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 469668
4099  - http://biorxiv.org/content/early/2019/05/29/469668.short
4100  - http://biorxiv.org/content/early/2019/05/29/469668.full
AB  - Mitochondrial dysfunction has been implicated in many pathological conditions and diseases. The normal functioning of mitochondria relies on maintaining the inner mitochondrial membrane (IMM) potential (a.k.a. ΔΨm) that is essential for ATP synthesis, Ca2+ homeostasis, redox balance and regulation of other key signaling pathways such as mitophagy and apoptosis. However, the detailed mechanisms by which ΔΨm regulates cellular function remain incompletely understood, partially due to difficulty of manipulating ΔΨm with spatiotemporal resolution, reversibility, or cell type specificity. To address this need, we have developed a next-generation optogenetic-based technique for controllable mitochondrial depolarization with light. We demonstrate successful targeting of the heterologous Channelrhodopsin-2 (ChR2) fusion protein to the IMM and formation of functional cationic channels capable of light-induced selective ΔΨm depolarization and mitochondrial autophagy. Importantly, we for the first time show that optogenetic-mediated mitochondrial depolarization can be well-controlled to differentially influence the fate of cells expressing mitochondrial ChR2: while sustained moderate light illumination induces substantial apoptotic cell death, transient mild light illumination elicits cytoprotection via mitochondrial preconditioning. Finally, we show that Parkin overexpression exacerbates, instead of ameliorating, mitochondrial depolarization-mediated cell death in HeLa cells. In summary, we provide evidence that the described mitochondrial-targeted optogenetics may have a broad application for studying the role of mitochondria in regulating cell function and fate decision.