scholarly journals Fully Characterized Mature Human iPS- and NMP-Derived Motor Neurons Thrive Without Neuroprotection in the Spinal Contusion Cavity

2022 ◽  
Vol 15 ◽  
Author(s):  
Zachary T. Olmsted ◽  
Cinzia Stigliano ◽  
Brandon Marzullo ◽  
Jose Cibelli ◽  
Philip J. Horner ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Progenitor Cells ◽  
Motor Neurons ◽  
Ex Vivo ◽  
Cervical Spinal Cord ◽  
Neural Cell ◽  
Oligodendrocyte Progenitor Cells ◽  
Limited Information ◽  
Cord Injury

Neural cell interventions in spinal cord injury (SCI) have focused predominantly on transplanted multipotent neural stem/progenitor cells (NSPCs) for animal research and clinical use due to limited information on survival of spinal neurons. However, transplanted NSPC fate is unpredictable and largely governed by injury-derived matrix and cytokine factors that are often gliogenic and inflammatory. Here, using a rat cervical hemicontusion model, we evaluate the survival and integration of hiPSC-derived spinal motor neurons (SMNs) and oligodendrocyte progenitor cells (OPCs). SMNs and OPCs were differentiated in vitro through a neuromesodermal progenitor stage to mimic the natural origin of the spinal cord. We demonstrate robust survival and engraftment without additional injury site modifiers or neuroprotective biomaterials. Ex vivo differentiated neurons achieve cervical spinal cord matched transcriptomic and proteomic profiles, meeting functional electrophysiology parameters prior to transplantation. These data establish an approach for ex vivo developmentally accurate neuronal fate specification and subsequent transplantation for a more streamlined and predictable outcome in neural cell-based therapies of SCI.

scholarly journals Restoration of breathing after opioid overdose and spinal cord injury using temporal interference stimulation

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Michael D. Sunshine ◽  
Antonino M. Cassarà ◽  
Esra Neufeld ◽  
Nir Grossman ◽  
Thomas H. Mareci ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Neurons ◽  
Drug Overdose ◽  
Cervical Spinal Cord ◽  
Opioid Overdose ◽  
Electrode Position ◽  
Spinal Motor Neurons ◽  
Cord Injury ◽  
Low Amplitude

AbstractRespiratory insufficiency is a leading cause of death due to drug overdose or neuromuscular disease. We hypothesized that a stimulation paradigm using temporal interference (TI) could restore breathing in such conditions. Following opioid overdose in rats, two high frequency (5000 Hz and 5001 Hz), low amplitude waveforms delivered via intramuscular wires in the neck immediately activated the diaphragm and restored ventilation in phase with waveform offset (1 Hz or 60 breaths/min). Following cervical spinal cord injury (SCI), TI stimulation via dorsally placed epidural electrodes uni- or bilaterally activated the diaphragm depending on current and electrode position. In silico modeling indicated that an interferential signal in the ventral spinal cord predicted the evoked response (left versus right diaphragm) and current-ratio-based steering. We conclude that TI stimulation can activate spinal motor neurons after SCI and prevent fatal apnea during drug overdose by restoring ventilation with minimally invasive electrodes.

The fate and function of oligodendrocyte progenitor cells after traumatic spinal cord injury

Glia ◽  
2019 ◽  
Vol 68 (2) ◽  
pp. 227-245 ◽  
Author(s):  
Greg J. Duncan ◽  
Sohrab B. Manesh ◽  
Brett J. Hilton ◽  
Peggy Assinck ◽  
Jason R. Plemel ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Progenitor Cells ◽  
Traumatic Spinal Cord Injury ◽  
Oligodendrocyte Progenitor Cells ◽  
Oligodendrocyte Progenitor ◽  
Cord Injury ◽  
And Function

scholarly journals Reactive oligodendrocyte progenitor cells (re-)myelinate the regenerating zebrafish spinal cord

Development ◽  
2020 ◽  
Vol 147 (24) ◽  
pp. dev193946 ◽  
Author(s):  
Vasiliki Tsata ◽  
Volker Kroehne ◽  
Daniel Wehner ◽  
Fabian Rost ◽  
Christian Lange ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Progenitor Cells ◽  
Transcriptional Profiling ◽  
Oligodendrocyte Progenitor Cells ◽  
Lesion Site ◽  
Oligodendrocyte Progenitor ◽  
Functional Deficits ◽  
Myelin Sheaths ◽  
Cord Injury ◽  
Global Reduction

ABSTRACTSpinal cord injury (SCI) results in loss of neurons, oligodendrocytes and myelin sheaths, all of which are not efficiently restored. The scarcity of oligodendrocytes in the lesion site impairs re-myelination of spared fibres, which leaves axons denuded, impedes signal transduction and contributes to permanent functional deficits. In contrast to mammals, zebrafish can functionally regenerate the spinal cord. Yet, little is known about oligodendroglial lineage biology and re-myelination capacity after SCI in a regeneration-permissive context. Here, we report that, in adult zebrafish, SCI results in axonal, oligodendrocyte and myelin sheath loss. We find that OPCs, the oligodendrocyte progenitor cells, survive the injury, enter a reactive state, proliferate and differentiate into oligodendrocytes. Concomitantly, the oligodendrocyte population is re-established to pre-injury levels within 2 weeks. Transcriptional profiling revealed that reactive OPCs upregulate the expression of several myelination-related genes. Interestingly, global reduction of axonal tracts and partial re-myelination, relative to pre-injury levels, persist at later stages of regeneration, yet are sufficient for functional recovery. Taken together, these findings imply that, in the zebrafish spinal cord, OPCs replace lost oligodendrocytes and, thus, re-establish myelination during regeneration.

scholarly journals Posteroanterior Cervical Transcutaneous Spinal Cord Stimulation: Interactions with Cortical and Peripheral Nerve Stimulation

2021 ◽  
Vol 10 (22) ◽  
pp. 5304
Author(s):  
Jaclyn R. Wecht ◽  
William M. Savage ◽  
Grace O. Famodimu ◽  
Gregory A. Mendez ◽  
Jonah M. Levine ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Motor Cortex ◽  
Motor Neurons ◽  
Nerve Stimulation ◽  
Spinal Cord Stimulation ◽  
Cervical Spinal Cord ◽  
Hand Function ◽  
Median Nerve Stimulation ◽  
Cord Injury ◽  
Transcutaneous Spinal Cord Stimulation

Transcutaneous spinal cord stimulation (TSCS) has demonstrated potential to beneficially modulate spinal cord motor and autonomic circuitry. We are interested in pairing cervical TSCS with other forms of nervous system stimulation to enhance synaptic plasticity in circuits serving hand function. We use a novel configuration for cervical TSCS in which the anode is placed anteriorly over ~C4–C5 and the cathode posteriorly over ~T2–T4. We measured the effects of single pulses of TSCS paired with single pulses of motor cortex or median nerve stimulation timed to arrive at the cervical spinal cord at varying intervals. In 13 participants with and 15 participants without chronic cervical spinal cord injury, we observed that subthreshold TSCS facilitates hand muscle responses to motor cortex stimulation, with a tendency toward greater facilitation when TSCS is timed to arrive at cervical synapses simultaneously or up to 10 milliseconds after cortical stimulus arrival. Single pulses of subthreshold TSCS had no effect on the amplitudes of median H-reflex responses or F-wave responses. These findings support a model in which TSCS paired with appropriately timed cortical stimulation has the potential to facilitate convergent transmission between descending motor circuits, segmental afferents, and spinal motor neurons serving the hand. Studies with larger numbers of participants and repetitively paired cortical and spinal stimulation are needed.

scholarly journals Smad Interacting Protein-1 is Essential for Oligodendrocyte Differentiation

2021 ◽  
Author(s):  
Ziwei Chen ◽  
Yuanmei Wang ◽  
Xiaobin Fan ◽  
Jufang Huang ◽  
Chunling Fan
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Mapk Pathway ◽  
Demyelinating Diseases ◽  
Oligodendrocyte Progenitor Cells ◽  
Oligodendrocyte Differentiation ◽  
Interacting Protein ◽  
Erk Mapk ◽  
Cord Injury

Abstract Precursor/stem cell substitutive therapy to promote remyelination is an ideal strategy for central nervous system demyelinating diseases such as spinal cord injury (SCI). However, the microenvironment of the injured area is not conducive to the survival, differentiation, and functions of the transplanted cells. Identifying and regulating the key inhibitory factors might be an important target for the treatment of demyelinating diseases. Smad interacting protein-1 (Sip1) is a transcription factor that binds to phosphorylated R-Smad in the nucleus, which promotes remyelination by inducing the differentiation of oligodendrocytes. In this study, we show that the expression of Sip1 is up-regulated and peaks by 1 day and then returns to normal levels 7 days after SCI. Most Sip1 positive cells were oligodendrocytes. In vitro, Sip1 was weakly expressed in the cytoplasm of oligodendrocyte progenitor cells (OPCs), significantly up-regulated in immature oligodendrocytes, and showed significant nuclear transposition. In contrast, Sip1 expression levels in mature oligodendrocytes decreased to levels similar to those in OPCs. The RNA interference of Sip1 in OPCs reduced the level of myelin basic protein (a mature oligodendrocyte marker protein, MBP) and pERK1/2 (a key molecule of the ERK/MAPK pathway) in oligodendrocytes. These findings suggest that Sip1 is essential for oligodendrocyte differentiation and might affect the ERK/MAPK signal pathway. The results provide a theoretical basis for the treatment of demyelinating lesions such as spinal cord injury by regulating Sip1 expression in oligodendrocytes.

scholarly journals Rapid and Efficient Differentiation of Rodent Neural Stem Cells into Oligodendrocyte Progenitor Cells

2019 ◽  
Vol 41 (1-2) ◽  
pp. 79-93 ◽  
Author(s):  
Shen Li ◽  
Jiao Zheng ◽  
Linlin Chai ◽  
Mengsi Lin ◽  
Ruocheng Zeng ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Stem Cells ◽  
Spinal Cord Injury ◽  
Stem Cell ◽  
Growth Factor ◽  
Neural Stem Cells ◽  
Progenitor Cells ◽  
Oligodendrocyte Progenitor Cells ◽  
Oligodendrocyte Progenitor ◽  
Cord Injury

Oligodendrocyte progenitor cells (OPCs) may have beneficial effects in cell replacement therapy of neurodegenerative disease owing to their unique capability to differentiate into myelinogenic oligodendrocytes (OLs) in response to extrinsic signals. Therefore, it is of significance to establish an effective differentiation methodology to generate highly pure OPCs and OLs from some easily accessible stem cell sources. To achieve this goal, in this study, we present a rapid and efficient protocol for oligodendroglial lineage differentiation from mouse neural stem cells (NSCs), rat NSCs, or mouse embryonic stem cell-derived neuroepithelial stem cells. In a defined culture medium containing Smoothened Agonist, basic fibroblast growth factor, and platelet-derived growth factor-AA, OPCs could be generated from the above stem cells over a time course of 4–6 days, achieving a cell purity as high as ∼90%. In particular, these derived OPCs showed high expandability and could further differentiate into myelin basic protein-positive OLs within 3 days or alternatively into glial fibrillary acidic protein-positive astrocytes within 7 days. Furthermore, transplantation of rodent NSC-derived OPCs into injured spinal cord indicated that it is a feasible strategy to treat spinal cord injury. Our results suggest a differentiation strategy for robust production of OPCs and OLs from rodent stem cells, which could provide an abundant OPC source for spinal cord injury.

scholarly journals Optimization of Microemulgel for Tizanidine Hydrochloride

2020 ◽  
Vol 19 (2) ◽  
pp. 158-179
Author(s):  
Swati Jagdale ◽  
Sujata Brahmane ◽  
Anuruddha Chabukswar
Keyword(s):  
Spinal Cord ◽  
Drug Release ◽  
Zeta Potential ◽  
Ternary Phase Diagram ◽  
Ex Vivo ◽  
Research Work ◽  
Isopropyl Myristate ◽  
Globule Size ◽  
Cord Injury

Background: Tizanidine hydrochloride acts centrally as a muscle relaxant. It is used for the treatment of painful muscle spasm, spasticity associated with multiple sclerosis or spinal cord injury and treatment of muscle spasticity in spinal cord disease. Tizanidine hydrochloride belongs to BCS class II. It has low oral bioavailability and short halflife. Incorporating this drug in microemulgel is an excellent way to overcome problems associated with the drug. Objective: Present research work was aimed to develop and optimize a microemulsion based gel system for tizanidine hydrochloride. Methods: Screening of oil, surfactant and co-surfactant was carried out. Ternary phase diagram was constructed to obtain concentration range of components. The prepared microemulsion was evaluated for pH, globule size, zeta potential, conductivity, density and viscosity. 32 level factorial design was applied to study the effect of concentration of carbopol 934 and HPMC K15M on % cumulative drug release and viscosity of microemulgel using software Design Expert. Microemulgel was evaluated for pH, spreadability, viscosity, syneresis, drug content, bioadhesive strength, in-vitro as well as ex-vivo diffusion study. Results: Microemulsion was prepared by using isopropyl myristate as oil, tween 80 as a surfactant and transcutol P as cosurfactant. Largest transparent microemulsion region was found with Smix ratio of 1:1. FE-SEM showed globule size 28μm for batch B1 and zeta potential was -1.27mV indicating good stability of the microemulsion. Optimised batch was F6 which showed 92% drug release within 8 hours. It followed the Korsmeyer-Peppas model. Conclusion: A stable, effective and elegant microemulgel formulation, exhibiting good in-vitro and ex-vivo drug release was formulated.

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