A dual-labeling probe to track functional mitochondria–lysosome interactions in live cells

Abstract

Mitochondria–lysosome interactions are essential for maintaining intracellular homeostasis. Although various fluorescent probes have been developed to visualize such interactions, they remain unable to label mitochondria and lysosomes simultaneously and dynamically track their interaction. Here, we introduce a cell-permeable, biocompatible, viscosity-responsive, small organic molecular probe, Coupa, to monitor the interaction of mitochondria and lysosomes in living cells. Through a functional fluorescence conversion, Coupa can simultaneously label mitochondria with blue fluorescence and lysosomes with red fluorescence, and the correlation between the red–blue fluorescence intensity indicates the progress of mitochondria–lysosome interplay during mitophagy. Moreover, because its fluorescence is sensitive to viscosity, Coupa allowed us to precisely localize sites of mitochondria–lysosome contact and reveal increases in local viscosity on mitochondria associated with mitochondria–lysosome contact. Thus, our probe represents an attractive tool for the localization and dynamic tracking of functional mitochondria–lysosome interactions in living cells.

A NIR Emitting Cyanine with Large Stokes’ Shift for Mitochondria and Identification of their Membrane Potential Disruption

“…The introduction of fluorescent-microscopy-based visualization has made a remarkable impact on mitochondria identification and tracking due to their high specificity and sensitivity. [10][11][12][13][14][15][16][17][18][19][20][21][22] The development of fluorescent dyes for studying mitochondrial morphological dynamics via fluorescent microscopy-based techniques are important to understand mitochondria related disease conditions (i. e., mitochondrial dysfunction). [23][24][25] An ideal mitochondrial selective fluorescent dye should exhibit high sensitivity towards mitochondrial membrane potential which is the key indicator of the mitochondrial dysfunction.…”

Prefused lysosomes cluster on autophagosomes regulated by VAMP8

“…To study lysosomal dynamics in autophagy, we used SIM to image lysosomes upon inducing autophagy by several different agents. First, HeLa cells were treated with 10 μM carbonyl cyanide mchlorophenylhydrazone (CCCP) [23][24][25], a common inducer of mitophagy, for 12 h before using staining to monitor lysosome cluster under SIM (Fig. 1a).…”

“…LysoTracker Red (LTR) is known to stain autolysosomes as well. We then used another lysosome specific tracker, Coupa-lyso, which goes to a dark state upon the formation of autolysosomes in mitophagy [25]. As shown in Fig.…”

A Carbonized Fluorescent Nucleolus Probe Discloses RNA Reduction in the Process of Mitophagy

“…To further understand this process, various fluorescent probes targeting lysosome-related organelles have been designed to visualize the spatiotemporal coordination among various organelles. [4][5][6][7][8][9] Nucleoli consisted of ribosomal DNA (rDNA), ribosomal RNA (rRNA) and proteins are important and highly dynamic subnuclear structures inside the cell, manipulating the synthesis of lysosome-related hydrolases and responding to the cellular environment. 10 Despite the significant roles of nucleoli in the mitophagy process, little attention is paid to the dynamic change of nucleoli.…”