A Fluorogenic Far Red-Emitting Molecular Viscometer for Ascertaining Lysosomal Stress in Live Cells and Caenorhabditis elegans

Abstract

The cellular physiochemical properties such as polarity, viscosity, and pH play a critical role in cellular homeostasis. The dynamic change of lysosomal viscosity in live cells associated with different environmental stress remains enigmatic and needs to be explored. We have developed a new class of Julolidine-based molecular viscometers with an extended π-conjugation to probe the lysosomal viscosity in live cells. High biocompatibility, pH tolerance, and the fluorogenic response with far red-emission (>600 nm) properties make these molecular viscometers suitable for live-cell fluorescence imaging in Caenorhabditis elegans. Among these probes, JIND-Mor is specifically designed to target lysosomes via simple modification. The real-time monitoring of lysosomal viscosity change under cellular stress was achieved. We believe that such a class of molecule viscometers has the potential to monitor lysosomal health in pathogenic conditions.

Harnessing solution and solid-state emissive materials from aliphatic biogenic amine-induced transient assembly and spontaneous disassembly

“…Nowadays, monitoring the bioactivity of lysosomes in live cells as well as animal models alongside the evaluation of their therapeutic effects has garnered immense attention. 62–64 We demonstrate that our developed probe Py-Spermine is an excellent candidate to study the effect of lipopolysaccharide-induced lysosomal membrane degradation in a time-dependent manner in live cells.…”

Intracellular Physical Properties with Small Organic Fluorescent Probes: Recent Advances and Future Perspectives

“…The latest report on the understanding of a lysosomal viscosity inside the live cell and in C. elegans under stress conditions came from our group. [112] In this report, we have developed an improved Julolidine-based molecular rotor (JIND-Mor, 101) with a large Stokes shift and far-red emission. For specific lysosome localization, we have appended a morpholine moiety at a remote position of JIND-Mor and the cellular stress-induced viscosity of the lysosome was assessed.…”

“…[132b] Li et al came up with a series of polarity-sensitive thiophene-based fluorophores to label lipid droplets with the detection of heterogeneity. [132d] The four probes, LDP1-LDP4 localize in LDs with LDP4 (112) having the maximum Pearson's correlation coefficient. Further performing ratiometric imaging using LDP4, the higher polarity of cytoplasm compared to LDs was reported.…”

“…Later, the authors monitored the fluctuation of viscosity inside the lysosome using dexamethasone as a viscosity enhancer of the lysosome. The latest report on the understanding of a lysosomal viscosity inside the live cell and in C. elegans under stress conditions came from our group [112] . In this report, we have developed an improved Julolidine‐based molecular rotor ( JIND‐Mor , 101 ) with a large Stokes shift and far‐red emission.…”

Water-soluble optical sensors: keys to detect aluminium in biological environment

“…In this scenario, the development of uorescent probe-based chemosensors is an active research eld that has garnered tremendous momentum over the past few years. [21][22][23][24][25][26] The use of optical probes is considered as the most convenient, inexpensive, effective, and rapid method for the detection of Al 3+ . Several probes based on rhodamine, 27,28 naphthol, 29 uorescein, 30 and spirobenzopyran 31 have been synthesized to detect Al 3+ cations exploiting their color and uorescence properties.…”