Two-photon excited red-green discoloration bioprobes for monitoring lipid droplets and lipid droplet-lysosomal autophagy

Lipid droplets (LDs) and their autophagy by lysosomes are closely related to a variety of physiological and pathological conditions. Therefore, identifying and tracking LDs and the dynamic process of autophagy can provide useful information for the diagnostics and treatment of related diseases. However, few organic small molecule-based fluorescent probes can specifically recognize LDs and dynamically track their autophagy process. Herein, we synthesized a discoloration fluorescent bioprobe DPABP-BI with distinguishable features including red fluorescence emission (630 nm), large Stokes shift (145 nm), two-photon excitation and outstanding photostability and biocompatibility. In particular, LDs could be specifically identified via the red fluorescence emission of DPABP-BI (colocalization constant of 0.98), while autophagolysosomes could be visualized via the green fluorescence emission of its acid-hydrolyzed product (colocalization constant of 0.90) to track the autophagy dynamic process. In addition, DPABP-BI enabled the specific recognition of fatty substances in zebrafish larvae. In this study, a two-photon excited red light small molecule probe was constructed to identify LDs and track their autophagy dynamic process by changing the fluorescence emission wavelength.

Automated summary

Researchers successfully synthesized a fluorescent probe DPABP-BI that can identify lipid droplets (LDs) and track their autophagy process. The probe features red fluorescence emission, large Stokes shift, two-photon excitation, outstanding photostability, and biocompatibility. LDs can be specifically identified through the red fluorescence emission of DPABP-BI, while autophagolysosomes can be visualized through the green fluorescence emission of its acid-hydrolyzed product to track the autophagy dynamic process. Additionally, DPABP-BI enables the specific recognition of fatty substances in zebrafish larvae.