Mitochondria MicroRNA Spatial Imaging via pH-Responsive Exonuclease-Assisted AIE Nanoreporter
Jinya Du1, Yuchun Qiao1, Xiangdan Meng1
1Beijing Key Laboratory for Bioengineering and Sensing Technology, School of Chemical and Bioengineering, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing 100083, People's Republic of China.
Abstract:
Mitochondrial microRNAs (mitomiRs) critically orchestrate mitochondrial functions. Spatial imaging of mitomiRs is essential to understand its clinical value in diagnosis and prognosis. However, the direct monitoring of mitomiRs in living cells remains a key challenge. Herein, we report an AIE nanoreporter strategy for mitomiRs imaging in living cells through pH-controlled exonuclease (Exo)-assisted target cycle signal amplification. The AIE-labeled DNA detection probes are conjugated on Exo III encapsulated polymeric nanoparticles (NPs) via consecutive adenines (polyA). The amplified sensing functions are off during the cytoplasm delivery process, and it can be spatially switched from off to on when in the alkaline mitochondria (about pH 8) after triphenylphosphonium (TPP)-mediated mitochondrial targeting. Where the NPs degraded to release Exo III and cancer-specific mitomiRs hybridize with AIE-labeled DNA detection probes to expose the cleavage site of released Exo III, enabling spatially restricted mitomiRs imaging. The mitomiRs expression fluctuation was also realized. This study contributes to a facile strategy that could easily extend to a broad application for the understanding of mitomiRs-related pathological processes.
Insights
We developed a novel AIE nanoreporter for imaging mitochondrial microRNAs (mitomiRs) in living cells. This pH-controlled system enables spatial signal amplification, advancing diagnostic and prognostic understanding of mitomiRs.
Area of Science:
- Biomedical Engineering
- Molecular Imaging
- Nanotechnology
Background:
- Mitochondrial microRNAs (mitomiRs) are crucial regulators of mitochondrial function.
- Accurate spatial imaging of mitomiRs is vital for clinical applications in diagnosis and prognosis.
- Directly monitoring mitomiRs in living cells presents significant technical challenges.
Purpose of the Study:
- To develop a novel strategy for the spatial imaging of mitomiRs in living cells.
- To enable pH-controlled, amplified signal detection of mitomiRs within mitochondria.
- To facilitate the understanding of mitomiRs' role in pathological processes.
Main Methods:
- Utilized Aggregation-Induced Emission (AIE) nanoreporters conjugated with DNA probes and exonuclease III (Exo III).
- Employed triphenylphosphonium (TPP) for targeted delivery to alkaline mitochondria (pH ~8).
- Implemented a pH-controlled, Exo III-assisted cyclic signal amplification triggered by mitomiR hybridization.
Main Results:
- Successfully demonstrated spatial imaging of mitomiRs in living cells using the AIE nanoreporter system.
- Achieved pH-controlled, spatially restricted signal amplification specifically within mitochondria.
- Monitored fluctuations in mitomiR expression, showcasing the system's dynamic capabilities.
Conclusions:
- The AIE nanoreporter strategy provides a facile and effective method for mitomiR imaging in living cells.
- This approach overcomes previous limitations in direct mitomiR monitoring.
- The technology holds potential for broad applications in studying mitomiR-related diseases and developing diagnostics.
