Disulfide-Reduction-Triggered Spontaneous Photoblinking Cy5 Probe for Nanoscopic Imaging of Mitochondrial Dynamics in Live Cells

2021 ◽  
Vol 93 (4) ◽  
pp. 2596-2602
Author(s):  
Wen Li ◽  
Wenhui Pan ◽  
Meina Huang ◽  
Zhigang Yang ◽  
Ying He ◽  
...  
2019 ◽  
Vol 8 (10) ◽  
pp. 1723
Author(s):  
Tamara Mirzapoiazova ◽  
Haiqing Li ◽  
Anusha Nathan ◽  
Saumya Srivstava ◽  
Mohd W. Nasser ◽  
...  

Mitochondria are dynamic organelles that constantly fuse and divide, forming dynamic tubular networks. Abnormalities in mitochondrial dynamics and morphology are linked to diverse pathological states, including cancer. Thus, alterations in mitochondrial parameters could indicate early events of disease manifestation or progression. However, finding reliable and quantitative tools for monitoring mitochondria and determining the network parameters, particularly in live cells, has proven challenging. Here, we present a 2D confocal imaging-based approach that combines automatic mitochondrial morphology and dynamics analysis with fractal analysis in live small cell lung cancer (SCLC) cells. We chose SCLC cells as a test case since they typically have very little cytoplasm, but an abundance of smaller mitochondria compared to many of the commonly used cell types. The 2D confocal images provide a robust approach to quantitatively measure mitochondrial dynamics and morphology in live cells. Furthermore, we performed 3D reconstruction of electron microscopic images and show that the 3D reconstruction of the electron microscopic images complements this approach to yield better resolution. The data also suggest that the parameters of mitochondrial dynamics and fractal dimensions are sensitive indicators of cellular response to subtle perturbations, and hence, may serve as potential markers of drug response in lung cancer.


Zygote ◽  
2015 ◽  
Vol 24 (4) ◽  
pp. 517-528 ◽  
Author(s):  
T. Yamochi ◽  
S. Hashimoto ◽  
A. Amo ◽  
H. Goto ◽  
M. Yamanaka ◽  
...  

SummaryMeiotic maturation of oocytes requires a variety of ATP-dependent reactions, such as germinal vesicle breakdown, spindle formation, and rearrangement of plasma membrane structure, which is required for fertilization. Mitochondria are accordingly expected be localized to subcellular sites of energy utilization. Although microtubule-dependent cellular traffic for mitochondria has been studied extensively in cultured neuronal (and some other somatic) cells, the molecular mechanism of their dynamics in mammalian oocytes at different stages of maturation remains obscure. The present work describes dynamic aspects of mitochondria in porcine oocytes at the germinal vesicle stage. After incubation of oocytes with MitoTracker Orange followed by centrifugation, mitochondria-enriched ooplasm was obtained using a glass needle and transferred into a recipient oocyte. The intracellular distribution of the fluorescent mitochondria was then observed over time using a laser scanning confocal microscopy equipped with an incubator. Kinetic analysis revealed that fluorescent mitochondria moved from central to subcortical areas of oocytes and were dispersed along plasma membranes. Such movement of mitochondria was inhibited by either cytochalasin B or cytochalasin D but not by colcemid, suggesting the involvement of microfilaments. This method of visualizing mitochondrial dynamics in live cells permits study of the pathophysiology of cytoskeleton-dependent intracellular traffic of mitochondria and associated energy metabolism during meiotic maturation of oocytes.


2019 ◽  
Author(s):  
Xusan Yang ◽  
Zhigang Yang ◽  
Ying He ◽  
Chunyan Shan ◽  
Wei Yan ◽  
...  

AbstractMitochondria play a critical role in generating energy to support the entire lifecycle of biological cells, yet it is still unclear how their morphological structures evolve to regulate their functionality. Conventional fluorescence microscopy can only provide ∼300 nm resolution, which is insufficient to visualize mitochondrial cristae. Here, we developed an enhanced squaraine variant dye (MitoESq-635) to study the dynamic structures of mitochondrial cristae in live cells at superresolution. The low saturation intensity and high photostability make it ideal for long-term, high-resolution STED nanoscopy. We demonstrate the time-lapsed imaging of the mitochondrial inner membrane over 50 minutes in living HeLa cells at 35.2 nm resolution for the first time. The forms of the cristae during mitochondrial fusion and fission can be clearly resolved. Our study demonstrates the emerging capability of optical STED nanoscopy to investigate intracellular physiological processes at nanoscale resolution for long periods of time with minimal phototoxicity.


2020 ◽  
Author(s):  
Weiwei Zou ◽  
Qixin Chen ◽  
Jesse Slone ◽  
Li Yang ◽  
Xiaoting Lou ◽  
...  

Abstract SLC25A46 mutations have been found to lead to mitochondrial hyper-fusion and reduced mitochondrial respiratory function, which results in optic atrophy, cerebellar atrophy, and other clinical symptoms of mitochondrial disease. However, it is generally believed that mitochondrial fusion is attributable to increased mitochondrial oxidative phosphorylation (OXPHOS)[1], which is inconsistent with the decreased OXPHOS of highly-fused mitochondria observed in previous studies. In this paper, we have used the live-cell nanoscope to observe and quantify the structure of mitochondrial cristae, and the behavior of mitochondria and lysosomes in patient-derived SLC25A46 mutant fibroblasts. The results show that the crista have been markedly damaged in the mutant fibroblasts, but that there is no corresponding increase in mitophagy. This study suggests that severely damaged mitochondrial cristae might be the predominant cause of reduced OXPHOS in SLC25A46 mutant fibroblasts. This study demonstrates the utility of nanoscope-based imaging for realizing the sub-mitochondrial morphology, mitophagy and mitochondrial dynamics in live cells, which may be particularly helpful for the quick assessment and diagnosis of mitochondrial abnormalities.


Author(s):  
Shinya Inoué

This paper reports progress of our effort to rapidly capture, and display in time-lapsed mode, the 3-dimensional dynamic architecture of active living cells and developing embryos at the highest resolution of the light microscope. Our approach entails: (A) real-time video tape recording of through-focal, ultrathin optical sections of live cells at the highest resolution of the light microscope; (B) repeat of A at time-lapsed intervals; (C) once each time-lapsed interval, an image at home focus is recorded onto Optical Disk Memory Recorder (OMDR); (D) periods of interest are selected using the OMDR and video tape records; (E) selected stacks of optical sections are converted into plane projections representing different view angles (±4 degrees for stereo view, additional angles when revolving stereos are desired); (F) analysis using A - D.


Author(s):  
E. D. Salmon ◽  
J. C. Waters ◽  
C. Waterman-Storer

We have developed a multi-mode digital imaging system which acquires images with a cooled CCD camera (Figure 1). A multiple band pass dichromatic mirror and robotically controlled filter wheels provide wavelength selection for epi-fluorescence. Shutters select illumination either by epi-fluorescence or by transmitted light for phase contrast or DIC. Many of our experiments involve investigations of spindle assembly dynamics and chromosome movements in live cells or unfixed reconstituted preparations in vitro in which photodamage and phototoxicity are major concerns. As a consequence, a major factor in the design was optical efficiency: achieving the highest image quality with the least number of illumination photons. This principle applies to both epi-fluorescence and transmitted light imaging modes. In living cells and extracts, microtubules are visualized using X-rhodamine labeled tubulin. Photoactivation of C2CF-fluorescein labeled tubulin is used to locally mark microtubules in studies of microtubule dynamics and translocation. Chromosomes are labeled with DAPI or Hoechst DNA intercalating dyes.


Author(s):  
K.I. Pagh ◽  
M.R. Adelman

Unicellular amoebae of the slime mold Physarum polycephalum undergo marked changes in cell shape and motility during their conversion into flagellate swimming cells (l). To understand the processes underlying motile activities expressed during the amoebo-flagellate transformation, we have undertaken detailed investigations of the organization, formation and functions of subcellular structures or domains of the cell which are hypothesized to play a role in movement. One focus of our studies is on a structure, termed the “ridge” which appears as a flattened extension of the periphery along the length of transforming cells (Fig. 1). Observations of live cells using Nomarski optics reveal two types of movement in this region:propagation of undulations along the length of the ridge and formation and retraction of filopodial projections from its edge. The differing activities appear to be associated with two characteristic morphologies, illustrated in Fig. 1.


2013 ◽  
pp. 1-1
Author(s):  
Ciara McCarthy ◽  
Philip Voyias ◽  
Adaikala Antonysunil ◽  
Alison Harte ◽  
Ponnusamy Saravanan ◽  
...  

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