ESPE Abstracts

Background: Human milk is considered the most advantageous source of nourishment for infants. Although there is a growing body of evidence showing that human milk feeding fosters early neurodevelopment, the underlying process is still not completely known. Indeed, clinical and animal research has linked human milk to enhanced myelination in the infant's central nervous system, however, access to human oligodendrocytes and neurons in the early stages of development has been limited, making it difficult to comprehend the potential effects of human milk components on myelination.

Aims: To test if physiological concentrations of short-chain fatty acids (butyrate, propionate, acetate) could promote early myelination in a human co-culture of oligodendrocytes and cortical neurons.

Methods: Neonatal oligodendrocytes as well as cortical neurons were generated by direct differentiation using human induced pluripotent stem cells (iPSC). Each cell line was validated separately at different time points. Specific cell lineage markers expression was analyzed by immunofluorescence, qRT-PCR, and western blot. Cortical neurons (day 37) and oligodendrocyte progenitor cells (day 67) were then combined into a co-culture and grown together for additional 28 days. Markers of myelination (oligodendrocyte transcription factor (Olig2), myelin basic protein (MBP), and O4) were probed following treatment of the co-culture with several concentrations of butyrate, propionate, and acetate.

Results: Short-chain fatty acids, particularly butyrate, significantly promoted oligodendrocyte differentiation. The co-culture resulted in almost 60% of O4+ promyelinating cells being further differentiated into Olig2+ and MBP+ mature oligodendrocytes within 10 days of treatment.

Conclusion: In summary, we established a 2D human co-culture model containing 50% of oligodendrocytes and 50% cortical neurons. Short-chain fatty acids treatment of the co-culture resulted in a significant increase in myelination markers within 10 days.