| 1. |
- Hu, Zhang-Jun, et al.
(författare)
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Real-time visualizing the regulation of reactive oxygen species on Zn2+ release in cellular lysosome by a specific fluorescent probe
- 2018
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Ingår i: Sensors and actuators. B, Chemical. - : ELSEVIER SCIENCE SA. - 0925-4005 .- 1873-3077. ; 264, s. 419-425
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Tidskriftsartikel (refereegranskat)abstract
- Reactive oxygen species (ROS) regulating the release of free zinc ions (Zn2+) in cellular lysosome is closely related to various pathways of cellular signal transduction, such as inflammation and oxidative stress. Directly visualizing Zn2+ release in lysosome is essential for in-depth understanding these physiological processes, and is still an atelic challenge. In this work, we successfully fabricate a lysosome-specific Zn2+ fluorescent probe and achieve the visualization of ROS-induced Zn2+ release in lysosome of inflammatory cells. The as-prepared probe combines a green fluorophore, an ionophore with five-dentate sites, and a morpholine as the lysosome-specific localization moiety. The fluorescence of the fluorophore in the free probe is suppressed by a photoinduced electron transfer (PET) process from nitrogen atoms in the ionophore. Upon the addition of Zn2+, the fluorescence can be promoted immediately, achieving the real-time detection. Meanwhile, the probe is sensitive and selective to Zn2+, which provides the capability to detect low-concentration of free Zn2+ in lysosomes. Accordingly, the Zn2+ release was clearly observed in lysosome with the increase of ROS levels when the inflammation occurred in living cells. (c) 2018 Published by Elsevier B.V.
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| 2. |
- Wang, Hong, et al.
(författare)
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Real-time tracking of mitochondrial dynamics by a dual-sensitive probe
- 2020
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 320
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Tidskriftsartikel (refereegranskat)abstract
- Tracking of mitochondrial dynamic processes including their morphology, biogenesis and elimination is of significance to deeply understand mitochondrial physiology and related diseases, which requires simultaneous and discriminative labeling of both mitochondria themselves and correlated downstream organelles. However, the combination of multiple fluorescent probes will bring the large invasive effect that seriously impacts the normal physiological processes of mitochondria within live cells. To address this issue, we herein construct a single molecular probe through the combination of two pH-sensitive fluorogens, hydroxyl-coumarin and rhodamine B, enabling the detection of intracellular microenvironmental pH variations. Importantly, the as-synthesized probe not only accumulates into mitochondria, indicated by cyan emission from hydroxyl-coumarin but also can be delivered to the downstream acidic autolysosomes upon the occurrence of mitophagy, indicated by red emission from rhodamine B. Taking advantage of a two-channel confocal microscopy strategy, we have achieved to real-time track the processes of mitochondrial replication, merge and autophagy.
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| 3. |
- Zhang, Xin, et al.
(författare)
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Light-Up Lipid Droplets Dynamic Behaviors Using a Red-Emitting Fluorogenic Probe
- 2020
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Ingår i: Analytical Chemistry. - : AMER CHEMICAL SOC. - 0003-2700 .- 1520-6882. ; 92:5, s. 3613-3619
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Tidskriftsartikel (refereegranskat)abstract
- Intracellular lipid metabolism occurs in lipid droplets (LDs), which is critical to the survival of cells. Imaging LDs is an intuitive way to understand their physiology in live cells. However, this is limited by the availability of specific probes that can properly visualize LDs in vivo. Here, an LDs-specific red-emitting probe is proposed to address this need, which is not merely with an ultrahigh signal-to-noise (S/N) ratio and a large Stokes shift (up to 214 nm) but also with superior resistance to photobleaching. The probe has been successfully applied to real-time tracking of intracellular LDs behaviors, including fusion, migration, and lipophagy processes. We deem that the proposed probe here offers a new possibility for deeper understanding of LDs-associated behaviors, elucidation of their roles and mechanisms in cellular metabolism, and determination of the transition between adaptive lipid storage and lipotoxicity as well.
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| 4. |
- zhang, xin, 1990-, et al.
(författare)
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Single-wavelength-excited fluorogenic nanoprobe for accurate real-time ratiometric analysis of broad pH fluctuations in mitophagy
- 2022
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Ingår i: Nano Reseach. - : Tsinghua University Press. - 1998-0124 .- 1998-0000. ; 15, s. 6515-6521
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Tidskriftsartikel (refereegranskat)abstract
- Mitophagy has a critical role in maintaining cellular homeostasis through acidic lysosomes engulfing excess or impaired mitochondria, thereby pH fluctuation is one of the most significant indicators for tracking mitophagy. Then such precise pH tracking demands the fluorogenic probe that has tailored contemporaneous features, including mitochondrial-specificity, excellent biocompatibility, wide pH-sensitive range of 8.0-4.0, and especially quantitative ability. However, available molecular probes cannot simultaneously meet all the requirements since it is extremely difficult to integrate multiple functionalities into a single molecule. To fully address this issue, we herein integrate two fluorogenic pH sensitive units, a mitochondria-specific block, cell-penetrating facilitator, and biocompatible segments into an elegant silica nano scaffold, which greatly ensures the applicability for real-time tracking of pH fluctuations in mitophagy. Most significantly, at a single wavelength excitation, the integrated pH-sensitive units have spectra-distinguishable fluorescence towards alkaline and acidic pH in a broad range that covers mitochondrial and lysosomal pH, thus enabling a ratiometric analysis of pH variations during the whole mitophagy. This work also provides constructive insights into the fabrication of advanced fluorescent nanoprobes for diverse biomedical applications.
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| 5. |
- Baum, Matthew L, et al.
(författare)
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CSMD1 regulates brain complement activity and circuit development
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Ingår i: Brain, Behavior, and Immunity. - 1090-2139.
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Tidskriftsartikel (refereegranskat)abstract
- Complement proteins facilitate synaptic elimination during neurodevelopmental pruning, but neural complement regulation is not well understood. CUB and Sushi Multiple Domains 1 (CSMD1) can regulate complement activity in vitro, is expressed in the brain, and is associated with increased schizophrenia risk. Beyond this, little is known about CSMD1 including whether it regulates complement activity in the brain or otherwise plays a role in neurodevelopment. We used biochemical, immunohistochemical, and proteomic techniques to examine the regional, cellular, and subcellular distribution as well as protein interactions of CSMD1 in the brain. To evaluate whether CSMD1 is involved in complement-mediated synapse elimination, we examined Csmd1-knockout mice and CSMD1-knockout human stem cell-derived neurons. We interrogated synapse and circuit development of the mouse visual thalamus, a process that involves complement pathway activity. We also quantified complement deposition on synapses in mouse visual thalamus and on cultured human neurons. Finally, we assessed uptake of synaptosomes by cultured microglia. We found that CSMD1 is present at synapses and interacts with complement proteins in the brain. Mice lacking Csmd1 displayed increased levels of complement component C3, an increased colocalization of C3 with presynaptic terminals, fewer retinogeniculate synapses, and aberrant segregation of eye-specific retinal inputs to the visual thalamus during the critical period of complement-dependent refinement of this circuit. Loss of CSMD1 in vivo enhanced synaptosome engulfment by microglia in vitro, and this effect was dependent on activity of the microglial complement receptor, CR3. Finally, human stem cell-derived neurons lacking CSMD1 were more vulnerable to complement deposition. These data suggest that CSMD1 can function as a regulator of complement-mediated synapse elimination in the CNS during development.
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| 6. |
- Ou, Pan, et al.
(författare)
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Gasotransmitter Regulation of Phosphatase Activity in Live Cells Studied by Three-Channel Imaging Correlation
- 2019
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 58:8, s. 2261-2265
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Tidskriftsartikel (refereegranskat)abstract
- Enzyme activity in live cells is dynamically regulated by small-molecule transmitters for maintaining normal physiological functions. A few probes have been devised to measure intracellular enzyme activities by fluorescent imaging, but the study of the regulation of enzyme activity via gasotransmitters in situ remains a long-standing challenge. Herein, we report a three-channel imaging correlation by a single dual-reactive fluorescent probe to measure the dependence of phosphatase activity on the H2S level in cells. The two sites of the probe reactive to H2S and phosphatase individually produce blue and green fluorescent responses, respectively, and resonance energy transfer can be triggered by their coexistence. Fluorescent analysis based on the three-channel imaging correlation shows that cells have an ideal level of H2S to promote phosphatase activity up to its maximum. Significantly, a slight deviation from this H2S level leads to a sharp decrease of phosphatase activity. The discovery further strengthens our understanding of the importance of H2S in cellular signaling and in various human diseases.
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| 7. |
- Shen, Jie, et al.
(författare)
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Real-time monitoring of lipid droplets growth via the fusion with fluorescent dye-labeled adiposomes
- 2020
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Ingår i: Dyes and pigments. - : ELSEVIER SCI LTD. - 0143-7208 .- 1873-3743. ; 182
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Tidskriftsartikel (refereegranskat)abstract
- Investigating lipid droplets (LDs) behaviours is essential to deeply understand the physiology of LDs, such as their growths, movements, fusion/division, and autophagy. Among these behaviours, the growth of LDs is one of the most difficult to track due to the very subtle morphology evolution in a short time window. The major obstacle is that conventional LDs-specific dyes with low photostability cannot indicate the LDs size change. To address this issue, we synthesize a hydrophobic and photostable fluorescent dye (TPA-AD) and load it into the neutral lipid micelles (as artificial adiposomes). The highly hydrophobic TPA-AD enables the specific accumulation into intracellular LDs and the ready loading artificial adiposomes. When the intracellular LDs take TPA-AD-labeled adiposomes, by fusion, the sizes of LDs gradually grow, and LDs are simultaneously lighted up by the fluorescence of TPA-AD. Importantly, the high photostability of TPA-AD ensures the enhanced fluorescence signals. The finding here will further strengthen the understanding of LDs dynamics and fat metabolism.
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| 8. |
- Yang, Guanqing, et al.
(författare)
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A Multi-responsive Fluorescent Probe Reveals Mitochondrial Nucleoprotein Dynamics with Reactive Oxygen Species Regulation through Super-resolution Imaging
- 2020
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 59:37, s. 16154-16160
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the biomolecular interactions in a specific organelle has been a long-standing challenge because it requires super-resolution imaging to resolve the spatial locations and dynamic interactions of multiple biomacromolecules. Two key difficulties are the scarcity of suitable probes for super-resolution nanoscopy and the complications that arise from the use of multiple probes. Herein, we report a quinolinium derivative probe that is selectively enriched in mitochondria and switches on in three different fluorescence modes in response to hydrogen peroxide (H2O2), proteins, and nucleic acids, enabling the visualization of mitochondrial nucleoprotein dynamics. STED nanoscopy reveals that the proteins localize at mitochondrial cristae and largely fuse with nucleic acids to form nucleoproteins, whereas increasing H(2)O(2)level leads to disassociation of nucleic acid-protein complexes.
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