Biophysics of Neuron-Glia Interactions
Roles and mechanisms of synuclein and ataxin-3 spreading in Parkinson and Machado-Joseph diseases (Martin Oheim)
Parkinson’s disease (PD) and Machado Joseph disease (MJD) represent two incurable prototypical neurodegenerative diseases associated with protein aggregation and progressive spread of disease in the brain. Preliminary evidence suggests that both disorders share a common mechanism where autophagosome trafficking and exosome secretion intersect.
While autophagosomes are important intracellular vesicles for routing proteins and organelles for lysosomal degradation, extracellular microvesicles (exosomes) contain collections of proteins, RNA and lipids that are important cell-to-cell carriers for intercellular signaling-molecules.
How this common mechanism causes PD and MJD will be investigated by the Synspread consortium* in neurons and astrocytes derived from PD and MJD patients’ inducible pluripotent stem cells (iPSC) cells, using state-of-the-art super-resolution imaging of autophagosome and exosome formation/secretion and 2-photon whole- brain imaging of cleared tissue to trace the routes of synuclein and ataxin-3 protein spreading. The results will be plugged into a novel computational model of aggregate and exosome propagation in the mouse brain to predict disease progression and identify biochemical pathways underlying progression.
This SynSpread project is expected to generate unique insights into the process of protein and aggregate spreading in PD, MJD and potentially other neurodegenerative disorders, and to lead to identification of new targets and modifiers for therapeutic intervention in a significant step towards treatment of patients.
- Luis Pereira de Almeida, CNC, University of Coimbra, Portugal (Coordinator)
- Jens C. Schwamborn, University of Luxembourg, Luxembourg
- Ronan MT Fleming, University of Luxembourg, Luxembourg
- ANR- A National Research Infrastructure for Biological Imaging: France BioImaging (2013-23)
- EU-JPND (2015-18)
Fast, large-field multi-color imaging of astrocyte organelle interactions at isotropic 100-nm resolution (Martin Oheim)
Most structured illumination microscopes use a physical or synthetic grating that is projected into the sample plane to generate a periodic illumination pattern. Albeit simple and cost-effective, this arrangement hampers fast or multi-color acquisition, which is a critical requirement for time-lapse imaging of cellular and sub-cellular dynamics. We designed and implemented an interferometric approach allowing large-field, fast, dual-color imaging at an isotropic 100-nm resolution based on a sub-diffraction fringe pattern generated by the interference of two colliding evanescent waves. Our all-mirror-based system generates illumination patterns of arbitrary orientation and period, limited only by the illumination aperture (NA) of the objective lens, the response time of a fast, piezo-driven tip-tilt mirror and the available fluorescence signal. At low µW laser powers suitable for long-period observation of life cells and with a camera exposure time of 20 ms, our system permits the acquisition of super-resolved 50 µm by 50 µm images at 3.3 Hz. The possibility it offers for rapidly adjusting the pattern between images is particularly advantageous for experiments that require multi-scale and multi-color information. We demonstrated the performance of our instrument by imaging the collective dynamics of mitochondria and the endoplasmic reticulum (ER) in cultured cortical astrocytes. As an illustration of dual-color excitation dual-color detection, we also resolve interaction sites between near-membrane mitochondria and the endoplasmic reticulum. Our TIRF-SIM microscope – now housing five lasers spanning the entire visible wavelength range – provides a versatile, compact and cost-effective arrangement for large-field super-resolution imaging, allowing the investigation of co-localization and dynamic interactions between organelles – important questions in both cell biology and neurophysiology
- D. Abi-Haidar (IMNC – CNRS UMR 8165, Orsay)
- B. Devaux & P. Varlet (CHSA, Sainte-Anne Hospital, Paris)
- National grants: ANR FranceBioImaging
- Région Ile-de-France (DIM C’nano)
- Vincent ARMAND, Assistant professor, Paris Descartes, Biophysics of Neuron-Glia Interactions
- vincent.armand@-Code a retirer pour éviter le SPAM-parisdescartes.fr, +33 1 42 86 42 21, room P368
- Maia BRUNSTEIN, Post-doctoral fellow, Biophysics of Neuron-Glia Interactions
- maia.brunstein@-Code a retirer pour éviter le SPAM-parisdescartes.fr, +33 1 42 86 42 22, room P362
- Clement RICARD, Assistant professor, Paris Descartes, Biophysics of Neuron-Glia Interactions
- clement.ricard@-Code a retirer pour éviter le SPAM-parisdescartes.fr, +33 1 42 86 42 22, room P362
- Near-Membrane Refractometry Using Supercritical Angle Fluorescence.
Brunstein M, Roy L, Oheim M : Biophys J, 2017
- Local energy on demand: Are spontaneous astrocytic Ca2+-microdomains the regulartory unit for astrocyte-neuron metabolic cooperation?
Oheim M, Schmidt E, Hirrlinger J : Brain Res Bull, 2017
- Dependence of descriptors of co-localization on microscope spatiotemporal resolution and the choice of regions of interest.
Brunstein M, Oheim M : Microsc Res Tech, 2016
- TIRF (Total Internal Reflection Fluorescence)
Martin Oheim : ELS, 2016
- Improving image contrast in fluorescence microscopy with nanostructured substrates.
Brunstein M, Cattoni A, Estrada L, Yacomotti AM : Opt Express, 2015
- Fluorescent Probes Used for Measuring Intracellular Calcium
Martin Oheim : ELS, 2015
- Astrocyte VAMP3 vesicles undergo Ca2+ -independent cycling and modulate glutamate transporter trafficking.
Li D, Hérault K, Zylbersztejn K, Lauterbach MA, Guillon M, Oheim M, Ropert N : J Physiol, 2015
- FRET-Based Nanobiosensors for Imaging Intracellular Ca(2+) and H⁺ Microdomains.
Zamaleeva AI, Despras G, Luccardini C, Collot M, de Waard M, Oheim M, Mallet JM, Feltz A : Sensors (Basel), 2015
- Eliminating unwanted far-field excitation in objective-type TIRF. Part I. identifying sources of nonevanescent excitation light.
Brunstein M, Teremetz M, Hérault K, Tourain C, Oheim M : Biophys J, 2014
- Eliminating unwanted far-field excitation in objective-type TIRF. Part II. combined evanescent-wave excitation and supercritical-angle fluorescence detection improves optical sectioning.
Brunstein M, Hérault K, Oheim M : Biophys J, 2014
- New red-fluorescent calcium indicators for optogenetics, photoactivation and multi-color imaging.
Oheim M, van’t Hoff M, Feltz A, Zamaleeva A, Mallet JM, Collot M : Biochim Biophys Acta, 2014
- Cell-penetrating nanobiosensors for pointillistic intracellular Ca2+-transient detection.
Zamaleeva AI, Collot M, Bahembera E, Tisseyre C, Rostaing P, Yakovlev AV, Oheim M, de Waard M, Mallet JM, Feltz A : Nano Lett, 2014
- Lack of evidence for vesicular glutamate transporter expression in mouse astrocytes.
Li D, Hérault K, Silm K, Evrard A, Wojcik S, Oheim M, Herzog E, Ropert N : J Neurosci, 2013
- New tools for investigating astrocyte-to-neuron communication.
Li D, Agulhon C, Schmidt E, Oheim M, Ropert N : Front Cell Neurosci, 2013
- Full-field dual-color 100-nm super-resolution imaging reveals organization and dynamics of mitochondrial and ER networks.
Brunstein M, Wicker K, Hérault K, Heintzmann R, Oheim M : Opt Express, 2013
- Nanocavity Linewidth Narrowing and Group Delay Enhancement by Slow Light Propagation and Nonlinear Effects
Grinberg P, Bencheikh K, Brunstein M, Yacomotti AM, Dumeige Y, Sagnes I, Raineri F, Bigot L, Levenson JA : Phys Rev Lett, 2012
- Excitability and self-pulsing in a Photonic Crystal Nanocavity
Brunstein M, Yacomotti AM, Sagnes I, Raineri F, Bigot L, Levenson A : Phys Rev A, 2012
- Enhancement of a nano cavity lifetime by induced slow light and nonlinear dispersions.
Grinberg P, Bencheikh K, Brunstein M, Yacomotti AM, Dumeige Y, Sagnes I, Raineri F, Bigot L, Levenson JA : Opt Express, 2012
- Optogenetic activation of LiGluR-expressing astrocytes evokes anion channel-mediated glutamate release.
Li D, Hérault K, Isacoff EY, Oheim M, Ropert N : J Physiol, 2012
- Calcium rubies: a family of red-emitting functionalizable indicators suitable for two-photon Ca2+ imaging.
Collot M, Loukou C, Yakovlev AV, Wilms CD, Li D, Evrard A, Zamaleeva A, Bourdieu L, Léger JF, Ropert N, Eilers J, Oheim M, Feltz A, Mallet JM : J Am Chem Soc, 2012