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Your search keyword '"Han, Shoufa"' showing total 255 results
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255 results on '"Han, Shoufa"'

5. Sensitive imaging of Endoplasmic reticulum (ER) autophagy with an acidity-reporting ER-Tracker

Author

Shi, Yilong, Zou, Xiaoxue, Zheng, Xianghui, Wu, Yimin, Han, Jiahuai, and Han, Shoufa

Subjects
Cell Biology, Molecular Biology
Abstract

Macroautophagic/autophagic turnover of endoplasmic reticulum (reticulophagy) is critical for cell health. Herein we reported a sensitive fluorescence-on imaging of reticulophagy using a small molecule probe (ER-proRed) comprised of green-emissive fluorinated rhodol for ER targeting and nonfluorescent rhodamine-lactam prone to lysosome-triggered red fluorescence. Partitioned in ER to exhibit green fluorescence, ER-proRed gives intense red fluorescence upon co-delivery with ER into acidic lysosomes. Serving as the signal of reticulophagy, the turning on of red fluorescence enables discernment of reticulophagy induced by starvation, varied levels of reticulophagic receptors, and chemical agents such as etoposide and sodium butyrate. These results show ER probes optically activatable in lysosomes, such as ER-proRed, offer a sensitive and simplified tool for studying reticulophagy in biology and diseases. Abbreviations: Baf-A1, bafilomycin A1; CCCP, carbonyl cyanide m-chlorophenyl hydrazone; CQ, chloroquine diphosphate; ER, endoplasmic reticulum; FHR, fluorinated hydrophobic rhodol; GFP, green fluorescent protein; Reticulophagy, selective autophagy of ER; RFP, red fluorescent protein; ROX, X-rhodamine; UPR, unfolded protein response

Published
2023
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17. In cellulo synthesis of dendrimeric sensors for fluorescence-on imaging of bacterial phagocytosis.

Author

Jiang, Feng, Shi, Yilong, Zou, Xiaoxue, Han, Jiahuai, and Han, Shoufa

Abstract

Methods for optical tracking of pathogen–host interactions are of biomedical significance. We herein have reported a high molecular weight pH sensor (Den-pH) that is assembled in bacteria and then stably trapped in bacteria irrespective of bacterial membrane potentials. Endowed with acidity-triggered red fluorescence, Den-pH allows signal-on tracking of S. aureus in phagocytosis by macrophages. Intra-bacterial formation of multifunctional optical probes, which offers the advantage of overcoming the liability of conventional potential-sensitive dyes to dissipate from stressed bacteria, offers a new tool to study stressed pathogens. [ABSTRACT FROM AUTHOR]

Published
2022
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27. Responsive hetero-organelle partition conferred fluorogenic sensing of mitochondrial depolarization† †Electronic supplementary information (ESI) available: Biodistribution of RC; cytotoxicity of RC-TPP; and analysis spectra of RC-TPP and RC. See DOI: 10.1039/c6sc04158b Click here for additional data file

Author

Xue, Zhongwei, Zhao, Hu, Liu, Jian, Han, Jiahuai, and Han, Shoufa

Subjects
Chemistry, health occupations, macromolecular substances, environment and public health
Abstract

A hetero-organelle partition and lysosome activable sensor was developed for fluorogenic detection of mitochondrial depolarization in autophagy and cell death., Malfunctioning organelles are often difficult to probe with classical organelle-homing sensors owing to disruption of physiological organelle-probe affinity. We herein report the use of a responsive hetero-organelle partition and signal activable probe (RC-TPP) for detecting mitochondrial depolarization, a pathologically relevant event featuring loss of the electrical potentials across the mitochondrial membrane (ΔΨ m). Partitioned in mitochondria to give blue fluorescence, RC-TPP relocates into lysosomes upon mitochondrial depolarization and exhibits red fluorescence triggered by lysosomal acidity, enabling determination of autophagy relevant mitochondrial depolarization and the chronological sequence of mitochondrial depolarization and lysosomal neutralization in distinct cell death signalling pathways. As an alternative to classic homo-organelle specific molecular systems, this hetero-organelle responsive approach provides a new perspective from which to study dysfunctional organelles.

Published
2016

32. Organelle-Directed Staudinger Reaction Enabling Fluorescence-on Resolution of Mitochondrial Electropotentials via a Self-Immolative Charge Reversal Probe

Author

Xue, Zhongwei, Zhu, Rui, Wang, Siyu, Li, Jian, Han, Jiahuai, Liu, Jian, and Han, Shoufa

Abstract

Organelles often feature parameters pertinent to functions and yet responsive to biochemical stress. The electropotential across the mitochondrial membrane (ΔΨm) is a crucial mediator of cell fates. Herein we report a bioorthogonal reaction enabled fluorescence-on probing of ΔΨm alterations featuring anionic fluorescein-triphenylphosphonium diad (F-TPP), which is released via intramitochondria Staudinger reaction triggered self-immolation of o-azidomethylbenzoylated F-TPP. Compared to classical cationic mitochondria-specific dyes, F-TPP is hydrophilic and negatively charged. Effectively discerning ΔΨm changes upon diverse stress inducers, the organelle-directed bioorthogonal imaging strategy offers unprecedented choices to probe mitochondrial biology with functional molecules that are otherwise inaccessible via physiological organelle-probe affinity.

Published
2024
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33. Imaging stressed organelles via sugar-conjugated color-switchable pH sensors.

Author

Zhang, Enkang, Wang, Siyu, Su, Xinhui, and Han, Shoufa

Subjects
LYSOSOMES, ORGANELLES, COLOR vision, SIALIC acids, DETECTORS
Abstract

Stressed organelles are often challenging to image with canonical organelle probes owing to their propensity to dissipate from stressed organelles. We herein report the imaging of stressed lysosomes with color-switchable glyco-probes that contain an entity of mannose-6-carboxylate or sialic acid for targeting to and long-term retention in stressed lysosomes, and a diad of fluorescein/rhodamine-X-lactam exhibiting dramatic red-to-green fluorescence shift upon pH elevation. Relative to acidotropic dyes prone to dissipate from pH-elevated lysosomes, both glyco-probes are stably trapped in lysosomes without resorting to lysosomal acidity. Importantly, these probes are red emissive in acidic lysosomes (pH 4.5–5.8), but switched to green fluorescence in lysosomes of pH 6.0–7.4, allowing dual color discrimination of lysosomal pH alterations in cell starvation. These results support the use of sugar-armed sensors to investigate stressed lysosomes in biology and disease. [ABSTRACT FROM AUTHOR]

Published
2020
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34. An in cellulo-activated multicolor cell labeling approach used to image dying cell clearance.

Author

Shi, Yilong, Zhu, Rui, Xue, Zhongwei, Han, Jiahuai, and Han, Shoufa

Subjects
CELL imaging, CELL communication, QUINONE methides, EPITHELIAL cells, HELA cells, DEAMINATION
Abstract

Dying cell clearance is critical for myriad biological processes such as tissue homeostasis. We herein report an enzyme-activated fluorescence cell labeling approach and its use for multicolor imaging of dying cell clearance. Diacetylated 4-hydroxymandelic acid (DHA)-conjugated dyes give rise to reactive quinone methides upon deacetylation in live cells, which in turn covalently labels cellular proteins. With partner cells tagged with distinct fluorescence, apoptotic cell clearance by Raw 264.7 macrophages and epithelial HeLa cells was captured by confocal microscopy, showing the potential of DHA-based cell labeling for investigating cell–cell interactions. [ABSTRACT FROM AUTHOR]

Published
2019
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38. Bifunctional CD22 ligands use multimeric immunoglobulins as protein scaffolds in assembly of immune complexes on B cells

Author

O'Reilly, Mary K., Collins, Brian E., Han, Shoufa, Liang Liao, Rillahan, Cory, Kitov, Pavel I., Bundle, David R., and Paulson, James C.

Subjects
Glycoproteins -- Structure, Glycoproteins -- Chemical properties, Immunoglobulins -- Structure, Immunoglobulins -- Chemical properties, Protein binding -- Analysis, Chemistry
Abstract

The use of a small molecule bifunctional ligands of CD22 that uses antibodies as protein scaffolds to assemble antibody-CD22 complexes of low valency (n = 2-10) on B cells is reported. The results provide a general method for the rational design of ligand-based probes for glycan-binding proteins and other low-affinity receptors using soluble multivalent proteins as scaffold, as an alternative to polymers, dendrimers or neo-glycoproteins.

Published
2008

44. Inhibitor coordination interactions in the binuclear manganese cluster of arginase

Author

Cama, Evis, Pethe, Stephanie, Boucher, Jean-Luc, Han, Shoufa, Emig, Frances A., Ash, David E., Viola, Ronald E., Mansuy, Daniel, and Christianson, David W.

Subjects
Manganese -- Atomic properties, Manganese -- Observations, Arginase -- Chemical properties, Chemical reactions -- Analysis, Biological sciences, Chemistry
Abstract

The structure and stability of the binuclear manganese cluster is examined. It was found that for catalytic activity, the stability of the manganese cluster is important to catalyze the hydrolysis of L-arginine to form urea.

Published
2004

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