Oligodendrocyte Progenitor Cell Transplantation Reduces White Matter Injury in a Fetal Goat Model

Background: Preterm white matter injury (PWMI) is the most common type of brain injury in preterm infants, in which, oligodendrocyte progenitor cells (OPCs) are predominantly damaged. In this study, human OPCs (hOPCs) were administered to a fetal goat model of PWMI to examine the differentiation potential and therapeutic effects of the cells on PWMI.

Methods: Preterm goat fetuses were subjected to hypoxic-ischemia (HI) via intermittent umbilical cord occlusion (5 min × 5). Twenty million hOPCs were administered via a nasal catheter 12 h after an HI insult, and brain tissues were collected 14 or 21 days after the HI insult. Myelin basic protein (MBP) and myelin-associated glycoprotein (MAG) were detected by immunofluorescence and western blotting techniques. The percentage of myelinated nerve fibers and g-ratio were examined using transmission electron microscopy. Inflammatory cells were detected by immunohistochemistry. Inflammatory and neurotrophic factors were measured using enzyme-linked immunosorbent assay.

Results: Our results showed that intermittent umbilical cord occlusion induced PWMI in fetal goats. Transplanted hOPCs can survive in periventricular and subcortical white matter. Further, transplanted hOPCs expressed markers of mature oligodendrocytes (MBP and MAG) and few cells expressed markers of preoligodendrocytes (NG2 and A2B5), suggesting that these cells can differentiate into mature oligodendrocytes in the brain. In addition, hOPCs administration increased MBP and MAG levels, percentage of myelinated nerve fibers, and thickness of the myelin sheath, indicating a reduction in PWMI. Furthermore, hOPCs did not increase the inflammatory response after HI. Interestingly, hOPC administration decreased tumor necrosis factor-alpha and increased glial-derived neurotrophic factor and brain-derived neurotrophic factor levels after HI, suggesting that additional mechanisms mediate the inflammatory microenvironment and neuroprotective effects.

Conclusions: Exogenous hOPCs can differentiate into mature oligodendrocytes in fetal goats and alleviate HI-induced PWMI. Transplantation of hOPCs is a promising strategy for treating PWMI.