[Long-term effect of oligodendrocyte precursor cell transplantation on a rat model of white matter injury in the preterm infant]

Glial-restricted progenitor cells: a cure for diseased brain?

The central nervous system (CNS) is home to neuronal and glial cells. Traditionally, glia was disregarded as just the structural support across the brain and spinal cord, in striking contrast to neurons, always considered critical players in CNS functioning. In modern times this outdated dogma is continuously repelled by new evidence unravelling the importance of glia in neuronal maintenance and function. Therefore, glia replacement has been considered a potentially powerful therapeutic strategy. Glial progenitors are at the center of this hope, as they are the source of new glial cells. Indeed, sophisticated experimental therapies and exciting clinical trials shed light on the utility of exogenous glia in disease treatment. Therefore, this review article will elaborate on glial-restricted progenitor cells (GRPs), their origin and characteristics, available sources, and adaptation to current therapeutic approaches aimed at various CNS diseases, with particular attention paid to myelin-related disorders with a focus on recent progress and emerging concepts. The landscape of GRP clinical applications is also comprehensively presented, and future perspectives on promising, GRP-based therapeutic strategies for brain and spinal cord diseases are described in detail.

Oligodendrocyte Development and Implication in Perinatal White Matter Injury

Perinatal white matter injury (WMI) is the most common brain injury in premature infants and can lead to life-long neurological deficits such as cerebral palsy. Preterm birth is typically accompanied by inflammation and hypoxic-ischemic events. Such perinatal insults negatively impact maturation of oligodendrocytes (OLs) and cause myelination failure. At present, no treatment options are clinically available to prevent or cure WMI. Given that arrested OL maturation plays a central role in the etiology of perinatal WMI, an increased interest has emerged regarding the functional restoration of these cells as potential therapeutic strategy. Cell transplantation and promoting endogenous oligodendrocyte function are two potential options to address this major unmet need. In this review, we highlight the underlying pathophysiology of WMI with a specific focus on OL biology and their implication for the development of new therapeutic targets.

[Protective effect of transplantation of human oligodendrocyte precursor cells in a rat model of white matter injury]

OBJECTIVE

To study the effect of human oligodendrocyte precursor cell (hOPC) transplantation in the treatment of white matter injury (WMI).

METHODS

Neonatal rats were randomly divided into a sham-operation group, a model group, and a transplantation group (n=10 each). At the age of 3 days, the rats in the model group and the transplantation group were treated with right common carotid artery ligation, followed by hypoxia for 2 hours, to prepare a rat model of WMI. hOPCs were isolated from a spontaneously aborted human fetal brain at week 11 of gestation, and then hOPCs were cultured and transplanted into the rats with WMI. At 3 months after transplantation, the water maze test was performed to evaluate neurological function, and an electron microscope was used to observe myelin sheath thickness and proliferation.

RESULTS

The place navigation test using the Morris water maze showed that the model group had a significantly longer escape latency than the sham-operation group, and compared with the model group, the transplantation group had a significant reduction in escape latency (P < 0.05). To a certain degree, hOPC transplantation alleviated cognitive impairment in rats with WMI at the age of 90 days. The electron microscope images showed that hOPC transplantation promoted remyelination in the brain of WMI rats. Compared with the sham-operation group, the model group had a significant increase in the g-ratio (total axon diameter/total fiber diameter). Compared with the model group, the transplantation group had a significant reduction in the g-ratio (P < 0.05).

CONCLUSIONS

Intrathecal hOPC transplantation may alleviate neurological injury and promote remyelination in a rat model of WMI.

[Neuroprotective effects of oligodendrocyte precursor cells on white matter damage in preterm infants]

White matter damage, characterized by demyelination due to the damage of oligodendrocyte precursor cells (OPCs), is the most common type of brain damage in preterm infants. Survivors are often subject to long-term neurodevelopmental sequelae because of the lack of effective treatment. In recent years, it has been found that cell transplantation has the potential for the treatment of white matter damage. OPCs are frequently used cells in cell transplantation therapy. With abilities of migration and myelinization, OPCs are the best seed cells for the treatment of white matter damage. Several studies have found that OPCs may not only replace impaired cells to reconstruct the structure and function of white matter, but also inhibit neuronal apoptosis, promote the proliferation of endogenous neural stem cells, and enhance the repairment of the blood-brain barrier. However, the clinical application of OPC transplantation therapy faces many challenges, such as the effectiveness, risk of tumorigenesis and immune rejection. With reference to these studies, this article reviewed the development of myelination, the obtainment of OPCs, the therapeutic mechanism as well as application research, and analyzed the current challenges of OPC transplantation, in order to provide a new direction for clinical treatment of white matter damage in preterm infants.