title: 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.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China).
authors.forename: Qiongqiong
authors.initials: Q
authors.lastname: Wan
authors.forename: Suming
authors.initials: S
authors.lastname: Chen
authors.forename: Wen
authors.initials: W
authors.lastname: Shi
authors.forename: Lihong
authors.initials: L
authors.lastname: Li
authors.forename: Huimin
authors.initials: H
authors.lastname: Ma
mesh_terms: D002232:Carbocyanines / Q000737:chemistry; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D006367:HeLa Cells; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008247:Lysosomes / Q000737:chemistry* / Q000378:metabolism; D061986:MCF-7 Cells; D018613:Microscopy, Confocal; D020112:Rhodamine 123 / Q000737:chemistry
chemical_list: D002232:Carbocyanines; D005456:Fluorescent Dyes; D020112:Rhodamine 123
keywords: dyes/pigments; fluorescent probes; heat shock; imaging agents; lysosomal pH