No abstract

No abstract

Rat adult hippocampal progenitor cells (AHPCs) are self-renewing, multipotent neural progenitors that have the ability to differentiate into neurons and glia. Previously, we demonstrated that coculture of AHPCs with postnatal day two, type 1 cortical astrocytes on laminin-coated micropatterned polymer substrates facilitates selective neuronal differentiation of the AHPCs 1. Under this condition, multi-dimensional cell-cell and/or cell-extracellular matrix interactions, as well as possible soluble factors released from astrocytes provided spatial and temporal control selectively enhancing neuronal differentiation and neurite alignment on topographically different regions of the same substrate. To investigate the potential role of astrocyte-derived soluble factors as cues involved in neuronal differentiation, a non-contact co-culture system was used. Under control conditions, approximately 14% of the AHPCs were immunoreactive (IR) for the neuronal marker, class III β-tubulin (TUJ1-IR). When co-cultured in physical contact with astrocytes, neuronal differentiation increased significantly to about 25%, consistent with our previous results. Moreover, under non-contact co-culture conditions using Transwell insert cultures, neuronal differentiation was dramatically increased to approximately 64%. Furthermore, neurite outgrowth from neuronal cell bodies was considerably greater on the patterned substrate, compared to the non-patterned planar substrate under non-contact co-culture conditions. Taken together, our results demonstrate that astrocyte-derived soluble factors provide cues for specific neuronal differentiation of AHPCs cultured on micropatterned substrates. In addition, a suppressive influence on neuronal differentiation appears to be mediated by contact with co-cultured astrocytes. These results provide important insights into mechanisms for controlling neural progenitor/stem cell differentiation and facilitate development of strategies for CNS repair.

This paper investigates the influence of micropatterned polymers and chemical modification on neural progenitor cell growth and differentiation in co-culture systems with astrocytes. We sought to develop strategies to facilitate nerve regeneration using a synergistic combination of guidance cues, investigating the cellular mechanisms of nerve repair using adult rat hippocampal progenitor cells (AHPCs). Our studies have shown that this synergistic combination of physical, chemical, and biological cues can lead to oriented growth of astrocytes and progenitor cells, can control and accelerate neurite outgrowth and alignment in vitro, and may influence differentiation of progenitor cells.