title: Rhodamine-based fluorescent probe for direct bio-imaging of lysosomal pH changes.
abstract: Intracellular pH plays a pivotal role in various biological processes. In eukaryotic cells, lysosomes contain numerous enzymes and proteins exhibiting a variety of activities and functions at acidic pH (4.5-5.5), and abnormal variation in the lysosomal pH causes defects in lysosomal function. Thus, it is important to investigate lysosomal pH in living cells to understand its physiological and pathological processes. In this work, we designed a one-step synthesized rhodamine derivative (RM) with morpholine as a lysosomes tracker, to detect lysosomal pH changes with high sensitivity, high selectivity, high photostability and low cytotoxicity. The probe RM shows a 140-fold fluorescence enhancement over a pH range from 7.4 to 4.5 with a pKa value of 5.23. Importantly, RM can detect the chloroquine-induced lysosomal pH increase and monitor the dexamethasone-induced lysosomal pH changes during apoptosis in live cells. All these features demonstrate its value of practical application in biological systems.
authors.affiliation: Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Changsha 410082, PR China.
authors.forename: Xue-Lin
authors.initials: XL
authors.lastname: Shi
authors.affiliation: School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, PR China. Electronic address: mgz1985419@163.com.
authors.forename: Guo-Jiang
authors.initials: GJ
authors.lastname: Mao
authors.affiliation: Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Changsha 410082, PR China; State Key Laboratory of Fine Chemicals, Dalian University of Technology, E224 West Campus 2, Linggong Road, Dalian 116024, PR China. Electronic address: xbzhang@hnu.edu.cn.
authors.forename: Xiao-Bing
authors.initials: XB
authors.lastname: Zhang
authors.affiliation: Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Changsha 410082, PR China.
authors.forename: Hong-Wen
authors.initials: HW
authors.lastname: Liu
authors.affiliation: School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, PR China.
authors.forename: Yi-Jun
authors.initials: YJ
authors.lastname: Gong
authors.affiliation: Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Changsha 410082, PR China.
authors.forename: Yong-Xiang
authors.initials: YX
authors.lastname: Wu
authors.affiliation: Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Changsha 410082, PR China.
authors.forename: Li-Yi
authors.initials: LY
authors.lastname: Zhou
authors.affiliation: Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Changsha 410082, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Changsha 410082, PR China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Tan
mesh_terms: D017209:Apoptosis; D001943:Breast Neoplasms / Q000175:diagnosis*; D003952:Diagnostic Imaging; D005260:Female; D005456:Fluorescent Dyes; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008247:Lysosomes / Q000737:chemistry*; D018892:Proton-Motive Force; D012235:Rhodamines; D013050:Spectrometry, Fluorescence; D014407:Tumor Cells, Cultured
chemical_list: D005456:Fluorescent Dyes; D012235:Rhodamines
keywords: Fluorescence probe; Live cells; Lysosomal pH; Rhodamine-morpholine (RM)