Retracing Schwann Cell Developmental Transitions in Embryonic Dissociated DRG/Schwann Cell Cocultures in Mice

Abstract

Embryonic Dissociated Dorsal Root Ganglia (DRG) cultures are often used to investigate the role of novel molecular pathways or drugs in Schwann cell development and myelination. These cultures largely recapitulate the order of cellular and molecular events that occur in Schwann cells of embryonic nerves. However, the timing of Schwann cell developmental transitions, notably the transition from Schwann Cell Precursors (SCP) to immature Schwann cells (iSC) and then to myelinating Schwann cells, has not been estimated so far in this culture system. In this study, we determined the expression profiles of Schwann cell developmental genes during the first week of culture and then compared our data to the expression profiles of these genes in developing spinal nerves. This helped in identifying that SCP transition into iSC between the 5th and 7th day in vitro. Furthermore, we also investigated the transition of immature cells into pro-myelinating and myelinating Schwann cells upon the induction of myelination in vitro. Our results suggest that Schwann cell differentiation beyond the immature stage can be observed as early as 4 days post the induction of myelination in cocultures. Finally, we compared the myelinating potential of coculture-derived Schwann cell monocultures to cultures established from neonatal sciatic nerves and found that both these culture systems exhibit similar myelinating phenotypes. In effect, our results allow for a better understanding and interpretation of coculture experiments especially in studies that aim to elucidate the role of a novel actor in Schwann cell development and myelination.

Melatonin signalling in Schwann cells during neuroregeneration

“…Taking into account reported similarities in the transcriptomic landscape, morphology and shared ontogenetic origin from the neural crest ( Jessen and Mirsky, 2019a ; Milosavljević et al, 2021 ), the ganglionic satellite glial cells have been hypothesised to represent an arrested developmental stage within the Schwann cell lineage ( George et al, 2018 ). This is further supported by the finding that ganglionic satellite cells can differentiate into Schwann cells ( Sundaram et al, 2021 ). Several attempts have been made to transcriptionally profile the Schwann cells ( Franssen et al, 2008 ; Ulrich et al, 2014 ; Arthur-Farraj et al, 2017 ; He et al, 2018 ; Silva et al, 2019 ; Chen et al, 2021 ; Brosius Lutz et al, 2022 ).…”

Schwann cells are axo-protective after injury irrespective of myelination status in mouse Schwann cell–neuron cocultures

“…Protocols exist where endogenous mouse SCs are used to myelinate dissociated or non-dissociated DRG explant cultures. ( Harty et al, 2019 ; Numata-Uematasu et al, 2023 ; Shen et al, 2014 ; Stettner et al, 2013 ; Sundaram et al, 2021 ). Furthermore, another protocol uses exogenous SCs seeded onto non-dissociated DRG explant cultures ( Päiväläinen et al, 2008 ).…”

Distinct axo-protective and axo-destructive roles for Schwann cells after injury in a novel compartmentalised mouse myelinating coculture system

“…Protocols exist where endogenous or exogenous mouse SCs are used to myelinate DRG explant cultures (Päiväläinen et al, 2008;Stettner et al, 2013). Additionally, a more recent published protocol used endogenous SCs to repopulate dissociated mouse DRG axons, however SCs were only able to attain the pro-myelinating stage in coculture, further demonstrating the difficulty to get cultured mouse SCs to form mature myelin (Sundaram et al, 2021). Moreover, all the prior methods described using endogenous SCs or DRG explants preclude many experimental uses, such as using SCs from different transgenic animals, separate transfection of SCs and neurons with viruses for live imaging, and use of microfluidic chambers to allow injury studies and separate drug treatments to neurons or SCs.…”