Lysosomal pH Rise during Heat Shock Monitored by a Lysosome‐Targeting Near‐Infrared Ratiometric Fluorescent Probe

Abstract

Heat stroke is a life-threatening condition, featuring a high body temperature and malfunction of many organ systems. The relationship between heat shock and lysosomes is poorly understood, mainly because of the lack of a suitable research approach. Herein, by incorporating morpholine into a stable hemicyanine skeleton, we develop a new lysosome-targeting near-infrared ratiometric pH probe. In combination with fluorescence imaging, we show for the first time that the lysosomal pH value increases but never decreases during heat shock, which might result from lysosomal membrane permeabilization. We also demonstrate that this lysosomal pH rise is irreversible in living cells. Moreover, the probe is easy to synthesize, and shows superior overall analytical performance as compared to the existing commercial ones. This enhanced performance may enable it to be widely used in more lysosomal models of living cells and in further revealing the mechanisms underlying heat-related pathology.

Photochromism and molecular logic gate operation of a water-compatible bis-glycosyl diarylethene

“…S4, ESI †). This value is similar to the pH range of the lysosome (3.8-5.0), 32 clearly demonstrating the potential of the system for bio-imaging applications. When the protonated diarylethene 1Ho was irradiated with UV light of 254 nm, a new absorbance band at 540 nm appeared (Fig.…”

Recent Development of Chemosensors Based on Cyanine Platforms

“…191 With the help of a typical lysosome-targeting moiety, morpholine, Ma and co-workers measured lysosomal pH changes in living cells by using sensor 155. Moreover, the change of lysosomal pH with temperature was also investigated, revealing the increase of the lysosomal pH during heat shock and the irreversibility of this process.…”

A lysosome-targeted and ratiometric fluorescent probe for imaging exogenous and endogenous hypochlorous acid in living cells

“…40,47 To monitor HOCl in lysosomes, the probe should remain stable in acidic environment with no fluorescence response. We tested the probe of Lyso-HA response of HOCl under neutral and acidic conditions ( Figure 2).…”