High-dimensional super-resolution imaging reveals heterogeneity and dynamics of subcellular lipid membranes

Abstract

Lipid membranes are found in most intracellular organelles, and their heterogeneities play an essential role in regulating the organelles’ biochemical functionalities. Here we report a Spectrum and Polarization Optical Tomography (SPOT) technique to study the subcellular lipidomics in live cells. Simply using one dye that universally stains the lipid membranes, SPOT can simultaneously resolve the membrane morphology, polarity, and phase from the three optical-dimensions of intensity, spectrum, and polarization, respectively. These high-throughput optical properties reveal lipid heterogeneities of ten subcellular compartments, at different developmental stages, and even within the same organelle. Furthermore, we obtain real-time monitoring of the multi-organelle interactive activities of cell division and successfully reveal their sophisticated lipid dynamics during the plasma membrane separation, tunneling nanotubules formation, and mitochondrial cristae dissociation. This work suggests research frontiers in correlating single-cell super-resolution lipidomics with multiplexed imaging of organelle interactome.

Polarisation optics for biomedical and clinical applications: a review

“…In other areas, polarimetry can be used to characterise the vectorial information of fluorescence dyes, as the dipole orientation of the fluorophore is encoded in the polarisation state of the emitted light 154 , 155 . The SOP of such emission is always in a linear state; hence the polarisation angle (PA) and intensity of the linear SOP are quantities that can be harnessed, such as in biomedical applications in super-resolution microscopy 153 , 181 , 182 . Here we briefly summarise common phantoms used for biomedical polarimetric techniques.…”

“… 154 , 155 . (ii) Fluorescence dipole orientation imaging 181 , 182 , 233 , 289 . The polarisation orientation is given as a demonstration.…”

“…The dipole orientation (and the fluorescence intensity) polarimetric detection technique plays an important role in thin biomedical sample analysis: e.g., in fluorescence polarisation microscopy (FPM) 194 , 195 , 232 , 233 ; FPM can be used to study the nuclear pore complex subcomplexes and the relative orientations 234 , or be used to study different types of cytoskeleton such as actin, myosin, kinesin, microtubule and septin—those closely related with the performance of the dipole behaviours 235 – 239 —enabling research such as ATP and ADP binding 237 . Advanced research has been adopted in super-resolution imaging harnessing fluorescent dipoles via polarised illumination, with applications such as revealing heterogeneity and dynamics of subcellular lipid membranes 181 , 240 , 241 . These fluorescence anisotropy properties also belong to the fundamental polarisation properties that are encoded in the MM.…”

Polarized upconversion luminescence from a single LiLuF4:Yb3+/Er3+ microcrystal for orientation tracking

“…Micropolarized spectroscopy that focuses on the luminescence of single lanthanide (Ln 3+ )-doped upconversion particles (UCPs) or their assemblies has recently attracted great attention, not only for its fundamental scientific importance but also because of its potential applications in diverse areas such as microscopic information transportation, microfluidics, single-particle tracking, and super-resolution bioimaging [1][2][3][4][5][6][7][8][9][10]. In contrast to anisotropic emitters such as semiconductor nanowires, quantum rods, and nanoplates that exhibit size-and shape-dependent polarized luminescence [11][12][13][14], Ln 3+ -doped UCPs show distinguished nature of emission polarization which is independent of the particle size and morphology [15][16][17][18][19].…”

Unveiling a Hidden Event in Fluorescence Correlative Microscopy by AFM Nanomechanical Analysis

“…In current work, we perform an AFM-fluorescence correlative microscopy study on a model system consisting of biomembrane (DOPC bilayer) interacting with a commonly used hydrophobic molecule, Nile red ( Ira and Krishnamoorthy, 1998 ; Jain and Das, 2006 ; Kurniasih et al, 2015 ; Levitt et al, 2015 ; Halder et al, 2018 ), having high efficacy staining intracellular neutral lipid droplets and phospholipid cell membranes. Very recently, Zhanghao et al ( Zhanghao et al, 2020 ) used Nile red to perform single-cell super-resolution lipidomic resolving the membrane morphology, polarity, and phase of cell membrane and subcellular organelles. Lipid order in outer leaflet of bacterial membrane was investigated with high-sensitivity fluorescent probe based on Nile red ( Bogdanov et al, 2020 ).…”