Neurogenesis potential of oligodendrocyte precursor cells from oligospheres and injured spinal cord

Abstract

Severe traumatic spinal cord injury (SCI) leads to long-lasting oligodendrocyte death and extensive demyelination in the lesion area. Oligodendrocyte progenitor cells (OPCs) are the reservoir of new mature oligodendrocytes during damaged myelin regeneration, which also have latent potential for neurogenic regeneration and oligospheres formation. Whether oligospheres derived OPCs can differentiate into neurons and the neurogenesis potential of OPCs after SCI remains unclear. In this study, primary OPCs cultures were used to generate oligospheres and detect the differentiation and neurogenesis potential of oligospheres. In vivo, SCI models of juvenile and adult mice were constructed. Combining the single-cell RNA sequencing (scRNA-seq), bulk RNA sequencing (RNA-seq), bioinformatics analysis, immunofluorescence staining, and molecular experiment, we investigated the neurogenesis potential and mechanisms of OPCs in vitro and vivo. We found that OPCs differentiation and oligodendrocyte morphology were significantly different between brain and spinal cord. Intriguingly, we identify a previously undescribed findings that OPCs were involved in oligospheres formation which could further differentiate into neuron-like cells. We also firstly detected the intermediate states of oligodendrocytes and neurons during oligospheres differentiation. Furthermore, we found that OPCs were significantly activated after SCI. Combining scRNA-seq and bulk RNA-seq data from injured spinal cord, we confirmed the neurogenesis potential of OPCs and the activation of endoplasmic reticulum stress after SCI. Inhibition of endoplasmic reticulum stress could effectively attenuate OPCs death. Additionally, we also found that endoplasmic reticulum may regulate the stemness and differentiation of oligospheres. These findings revealed the neurogenesis potential of OPCs from oligospheres and injured spinal cord, which may provide a new source and a potential target for spinal cord repair.

The origins and dynamic changes of C3- and S100A10-positive reactive astrocytes after spinal cord injury

“…B6.Cg-Gt(ROSA) 26Sor tm9(CAG−tdTomato)Hze / J female mice (n = 3), 8-week-old wild-type female mice (sham group, n = 9; SCI group, n = 9), 1-week-old (sham group, n = 6; SCI group, n = 6) and 2-week-old juvenile mice (sham group, n = 6; SCI group, n = 6), were used for spinal cord crush model construction. Contusion and crush models at T10 were established as we previously reported (Zhao et al, 2022). The sham-treated mice received laminectomy without contusion and crush.…”

“…The preparation of tissue slices, immunofluorescence experiments and analysis were carried out based on our previous methods (Zhao et al, 2022). Mice were euthanized at 2 weeks post injury (2 WPI).…”

“…To further reveal the dynamic changes in C3-and S100A10positive reactive astrocytes, we used RNA-seq to examine the transcriptomes of the lesion site at 2 weeks post injury (2 WPI), including sham and SCI group of 1-week-old mice (sham_1W, n = 3; SCI_1W, n = 3); sham and SCI group of 2-weekold mice (sham_2W, n = 3; SCI_2W, n = 3); sham and SCI group of 8-week-old mice (sham_8W, n = 3; SCI_8W, n = 3). RNA-seq was carried out as we previously described (Zhao et al, 2022). The sequence and sample data have been deposited in NCBI database under Sequence Read Archive (SRA) with Bioproject identification number PRJNA847738 (Accession number: SRR19612226 -SRR19612243).…”

Analysis of miRNA expression profile of sciatic nerve in rats with spinal cord injury

“…Due to the limited regenerative capacity of neural stem cells in the central nervous system, neurons in the spinal cord are hard to regenerate after injury or necrosis 4,7 . However, studies have shown that some non-coding RNAs and transcription factors can promote the recovery of local neural circuits by regulating the local microenvironment of the spinal cord, so as to maintain part of the nerve activity and protect the paralyzed limb [8][9][10] .…”

“…Currently, we do not know what changes occur in the downstream peripheral nerves after spinal cord injury that increase the di culty of wound healing in the skin and soft tissue. Spinal cord neurons cannot regenerate after injury, and rely on local microenvironment regulation to restore part of the neural circuit [10][11][12] . On the contrary, peripheral nerves have good regeneration ability under normal circumstances 8,13 .…”