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Optogenetics reveal delayed afferent synaptogenesis on grafted human induced pluripotent stem cell-derived neural progenitors.

Avaliani, Natalia LU ; Toft Sörensen, Andreas LU ; Ledri, Marco LU ; Bengzon, Johan LU ; Koch, Philipp; Brüstle, Oliver; Deisseroth, Karl; Andersson, My LU and Kokaia, Merab LU (2014) In Stem Cells 32(12). p.3088-3098
Abstract
Reprogramming of somatic cells into pluripotency stem cell state have opened new opportunities in cell replacement therapy and disease modeling in a number of neurological disorders. It still remains unknown, however, to what degree the grafted human induced pluripotent stem cells (hiPSCs) differentiate into a functional neuronal phenotype and if they integrate into the host circuitry. Here we present a detailed characterization of the functional properties and synaptic integration of hiPSC-derived neurons grafted in an in vitro model of hyperexcitable epileptic tissue, namely organotypic hippocampal slice cultures (OHSC), and in adult rats in vivo. The hiPSCs were first differentiated into long-term self-renewing neuroepithelial stem... (More)
Reprogramming of somatic cells into pluripotency stem cell state have opened new opportunities in cell replacement therapy and disease modeling in a number of neurological disorders. It still remains unknown, however, to what degree the grafted human induced pluripotent stem cells (hiPSCs) differentiate into a functional neuronal phenotype and if they integrate into the host circuitry. Here we present a detailed characterization of the functional properties and synaptic integration of hiPSC-derived neurons grafted in an in vitro model of hyperexcitable epileptic tissue, namely organotypic hippocampal slice cultures (OHSC), and in adult rats in vivo. The hiPSCs were first differentiated into long-term self-renewing neuroepithelial stem (lt-NES) cells, which are known to form primarily GABAergic neurons. When differentiated in OHSCs for six weeks, lt-NES cell-derived neurons displayed neuronal properties such as TTX-sensitive sodium currents and action potentials (APs), as well as both spontaneous and evoked postsynaptic currents, indicating functional afferent synaptic inputs. The grafted cells had a distinct electrophysiological profile compared to host cells in the OHSCs with higher input resistance, lower resting membrane potential and APs with lower amplitude and longer duration. To investigate the origin of synaptic afferents to the grafted lt-NES cell-derived neurons, the host neurons were transduced with Channelrhodopsin-2 (ChR2) and optogenetically activated by blue light. Simultaneous recordings of synaptic currents in grafted lt-NES cell-derived neurons using whole-cell patch-clamp technique at 6 weeks after grafting revealed limited synaptic connections from host neurons. Longer differentiation times, up to 24 weeks after grafting in vivo, revealed more mature intrinsic properties and extensive synaptic afferents from host neurons to the It-NES cell-derived neurons, suggesting that these cells require extended time for differentiation/maturation and synaptogenesis. However, even at this later time-point, the grafted cells maintained a higher input resistance. These data indicate that grafted lt-NES cell-derived neurons receive ample afferent input from the host brain. Since the lt-NES cells used in this study show a strong propensity for GABAergic differentiation, the host-to-graft synaptic afferents may facilitate inhibitory neurotransmitter release, and normalize hyperexcitable neuronal networks in brain diseases, e.g. such as epilepsy. Stem Cells 2014. (Less)
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author
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Contribution to journal
publication status
published
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in
Stem Cells
volume
32
issue
12
pages
3088 - 3098
publisher
AlphaMed Press
external identifiers
  • pmid:25183299
  • wos:000345593700006
  • scopus:84912077825
ISSN
1549-4918
DOI
10.1002/stem.1823
language
English
LU publication?
yes
id
d354eb38-0ad4-48bc-898b-82c784da40c9 (old id 4692455)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/25183299?dopt=Abstract
date added to LUP
2014-10-01 13:00:15
date last changed
2017-11-05 03:02:10
@article{d354eb38-0ad4-48bc-898b-82c784da40c9,
  abstract     = {Reprogramming of somatic cells into pluripotency stem cell state have opened new opportunities in cell replacement therapy and disease modeling in a number of neurological disorders. It still remains unknown, however, to what degree the grafted human induced pluripotent stem cells (hiPSCs) differentiate into a functional neuronal phenotype and if they integrate into the host circuitry. Here we present a detailed characterization of the functional properties and synaptic integration of hiPSC-derived neurons grafted in an in vitro model of hyperexcitable epileptic tissue, namely organotypic hippocampal slice cultures (OHSC), and in adult rats in vivo. The hiPSCs were first differentiated into long-term self-renewing neuroepithelial stem (lt-NES) cells, which are known to form primarily GABAergic neurons. When differentiated in OHSCs for six weeks, lt-NES cell-derived neurons displayed neuronal properties such as TTX-sensitive sodium currents and action potentials (APs), as well as both spontaneous and evoked postsynaptic currents, indicating functional afferent synaptic inputs. The grafted cells had a distinct electrophysiological profile compared to host cells in the OHSCs with higher input resistance, lower resting membrane potential and APs with lower amplitude and longer duration. To investigate the origin of synaptic afferents to the grafted lt-NES cell-derived neurons, the host neurons were transduced with Channelrhodopsin-2 (ChR2) and optogenetically activated by blue light. Simultaneous recordings of synaptic currents in grafted lt-NES cell-derived neurons using whole-cell patch-clamp technique at 6 weeks after grafting revealed limited synaptic connections from host neurons. Longer differentiation times, up to 24 weeks after grafting in vivo, revealed more mature intrinsic properties and extensive synaptic afferents from host neurons to the It-NES cell-derived neurons, suggesting that these cells require extended time for differentiation/maturation and synaptogenesis. However, even at this later time-point, the grafted cells maintained a higher input resistance. These data indicate that grafted lt-NES cell-derived neurons receive ample afferent input from the host brain. Since the lt-NES cells used in this study show a strong propensity for GABAergic differentiation, the host-to-graft synaptic afferents may facilitate inhibitory neurotransmitter release, and normalize hyperexcitable neuronal networks in brain diseases, e.g. such as epilepsy. Stem Cells 2014.},
  author       = {Avaliani, Natalia and Toft Sörensen, Andreas and Ledri, Marco and Bengzon, Johan and Koch, Philipp and Brüstle, Oliver and Deisseroth, Karl and Andersson, My and Kokaia, Merab},
  issn         = {1549-4918},
  language     = {eng},
  number       = {12},
  pages        = {3088--3098},
  publisher    = {AlphaMed Press},
  series       = {Stem Cells},
  title        = {Optogenetics reveal delayed afferent synaptogenesis on grafted human induced pluripotent stem cell-derived neural progenitors.},
  url          = {http://dx.doi.org/10.1002/stem.1823},
  volume       = {32},
  year         = {2014},
}