Human ex vivo spinal cord slice culture as a useful model of neural development, lesion, and allogeneic neural cell therapy

Chenhong Lin,Lena Holmberg,Simone Codeluppi,Per Uhlén,Teresa Fernandez-Zafra,Elisabet Åkesson,Jia Liu,Åsa Ekblad-Nordberg,Maria Lindskog,Cinzia Calzarossa,Erika Vazquez-Juarez,Xiaofei Li

doi:10.1186/s13287-020-01771-y

Abstract

BackgroundThere are multiple promising treatment strategies for central nervous system trauma and disease. However, to develop clinically potent and safe treatments, models of human-specific conditions are needed to complement in vitro and in vivo animal model-based studies.MethodsWe established human brain stem and spinal cord (cross- and longitudinal sections) organotypic cultures (hOCs) from first trimester tissues after informed consent by donor and ethical approval by the Regional Human Ethics Committee, Stockholm (lately referred to as Swedish Ethical Review Authority), and The National Board of Health and Welfare, Sweden. We evaluated the stability of hOCs with a semi-quantitative hOC score, immunohistochemistry, flow cytometry, Ca2+ signaling, and electrophysiological analysis. We also applied experimental allogeneic human neural cell therapy after injury in the ex vivo spinal cord slices.ResultsThe spinal cord hOCs presented relatively stable features during 7–21 days in vitro (DIV) (except a slightly increased cell proliferation and activated glial response). After contusion injury performed at 7 DIV, a significant reduction of the hOC score, increase of the activated caspase-3+ cell population, and activated microglial populations at 14 days postinjury compared to sham controls were observed. Such elevation in the activated caspase-3+ population and activated microglial population was not observed after allogeneic human neural cell therapy.ConclusionsWe conclude that human spinal cord slice cultures have potential for future structural and functional studies of human spinal cord development, injury, and treatment strategies.

Highlights

There are multiple promising treatment strategies for central nervous system trauma and disease
Generation of Human organotypic culture (hOC) slices from first trimester human central nervous system (CNS) In vitro observations by phase contrast microscopy To assess hOC stability and quality, we examined slices under a phase contrast microscope daily up to 21 days in vitro (DIV) (Fig. 1C)
There were some exceptions in brain stem-spinal cord (BS-spinal cord (SC)) slices, where the tissue integrity of the BS region in older cases (9–10.5 w. group) at 14 DIV and 21 DIV was compromised, slice area increased, gray and white matter areas were difficult to distinguish, edges were uneven, and dispersed cells covered almost all of the BS perimeter

Summary

Introduction

There are multiple promising treatment strategies for central nervous system trauma and disease. Human central nervous system (CNS) lesions, such as spinal cord injury (SCI), present limited spontaneous regenerative properties and largely lack available treatments offering functional improvement. Neural cell therapy represents one experimental treatment strategy to support structural and functional improvement. Lin et al Stem Cell Research & Therapy (2020) 11:320 after SCI with promising and significant results in SCI animal models [5,6,7,8,9]. Human allogeneic neural cell therapy clinical trials in chronic SCI [10, 11] presented feasibility and tolerability. To improve treatment efficacy and ensure safety, we need model systems mimicking human nervous system lesions and allogeneic conditions as closely as possible to elucidate mechanisms involved in injury progression as well as neuroprotection and repair

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