Molecular imaging of neural stem cell differentiation - a novel quantitative and noninvasive approach using imaging reporters
Final Report Abstract
The major aim of the present project was to establish a molecular imaging platform for noninvasive and quantitative cell fate imaging by validating a set of novel imaging reporters and cellspecific promoters, which allow the precise monitoring of neural stem cell (NSC) differentiation into neurons, astrocytes, and oligodendrocytes in vitro as well as in mouse models in vivo. Traditionally, investigations of stem cell applications, e.g. for studies evaluating their effect on neurological disorders, determine the number and fate of transplanted cells by immunostainings. However, that approach cannot refer the number of differentiated cells back to the initial cell number and the time profile of differentiation as only single ex vivo time points per animal are available. In this project, we succeeded in implementing an in vivo fate mapping toolbox for NSCs to monitor the differentiation into all three major brain cell types by bioluminescence and fluorescence imaging. In addition, we were able to apply the toolbox to immune cells and visualize the differential polarization of microglia into a pro-inflammatory M1- and an anti-inflammatory M2-type. For that approach, we have validated together with our collaboration partner Amit Jathoul (Cardiff, UK) novel fluorescence and bioluminescence imaging reporters, which give highest signals in combination with cell-specific promoters. The imaging reporters can be combined for in vivo and ex vivo high-throughput analysis in single as well as a dual-color approach, e.g. to monitor viability with a constitutive promoter and differentiation with a cell-specific promoter at the same time. This marks a biological breakthrough as our successfully tested approach can now be used to engineer cells for many different applications and visualize processes in vivo, which required sequential histology before. We will apply that technology in our experimental stroke studies in order to define the potential of specific cell lines to replace damaged tissue and correlate the survival/differentiation to behavioral improvement. Furthermore, the generated plasmids and cell lines are available for other researcher and are being used by other groups already (e.g. Prof. Peter Ponsaerts, University of Antwerp, Belgium). As a follow-up and to fully exploit the potential of the imaging toolbox, we are working together with Dr. Christian Roedel (University of Jena, Germany) on a novel optical setup, specifically designed to achieve higher sensitivity and spatial resolution than currently available with commercial imaging systems.
Publications
- A multi-modality platform to image stem cell graft survival in the naïve and stroke-damaged mouse brain. Biomaterials 2014; 35(7): 2218-26
Boehm-Sturm P, Aswendt M, Minassian A, Michalk S, Mengler L, Adamczak J, Mezzanotte L, Löwik C, Hoehn M
(See online at https://doi.org/10.1016/j.biomaterials.2013.11.085) - Aswendt M, Henn N, Michalk S, Schneider G, Steiner M, Bissa U, Dose C, Hoehn M. Novel Bimodal Iron Oxide Particles for Efficient Tracking of Human Neural Stem Cells in vivo. Nanomedicine 2015; 10(16):2499-2512
Aswendt M, Henn N, Michalk S, Schneider G, Steiner M, Bissa U, Dose C, Hoehn M
(See online at https://doi.org/10.2217/NNM.15.94) - Human neural stem cell intracerebral grafts show spontaneous early neuronal differentiation after several weeks. Biomaterials 2015; 44:143-154
Tennstaedt M, Aswendt M, Adamczak J, Selt M, Schneider G, Henn N, Schaefer C, Hoehn M
(See online at https://doi.org/10.1016/j.biomaterials.2014.12.038) - Neurobiological insights from bioluminescence imaging. Oncotarget 2017 8(41): 69198–69199
Aswendt M, Collmann FM, Hoehn M
(See online at https://dx.doi.org/10.18632/oncotarget.20302) - Neurogenesis upregulation on the healthy hemisphere after stroke enhances compensation for age-dependent decrease of basal neurogenesis. Neurobiology of Disease 2017; 99:47-57
Adamczak J, Aswendt M, Kreutzer C, Rotheneichner P, Riou A, Selt M, Beyrau A, Uhlenküken U, Diedenhofen M, Nelles M, Aigner L, Couillard-Despres S, Hoehn M
(See online at https://doi.org/10.1016/j.nbd.2016.12.015) - Perspectives of in vivo bioluminescence imaging: application to basic and translational neuroscience. Current Pharmaceutical Design 2017; 23:1963-1973
Vogel S, Collmann F, Hoehn M
(See online at https://doi.org/10.2174/1381612822666161226151811) - Initial graft size and not the innate immune response limit survival of engrafted neural stem cells. Journal of Tissue Engineering and Regenerative Medicine 2018; 12(3):784-793
Vogel S, Aswendt M, Nelles M, Henn N, Schneider G, Hoehn M
(See online at https://doi.org/10.1002/term.2497)
