eSC Derived hNP1 Neural Progenitors Astrocytic Differentiation

Protocol for Driving hNP1^TM Human Neural Progenitors to Astrocytes

There is a great demand for an easy way to generate human astrocytes in culture. I am pleased to present a protocol for differentiating our hNP1 Cells to Astrocytes. This comes from my friend Dr. Steve Stice and his team at ArunA Biomedical and University of Georgia: Majumder A, Dhara SK, Swetenburg R, Mithani M, Cao K, Medrzycki M, Fan Y, Stice SL. Inhibition of DNA methyltransferases and histone deacetylases induces astrocytic differentiation of neural progenitors. Stem Cell Res. 2013 Jul;11(1):574-86. doi: 10.1016/j.scr.2013.03.003. Epub 2013 Apr 2.

These enriched non-transformed human astrocyte progenitors will provide a critical cell source to further our understanding of how astrocytes play a pivotal role in neural function and development. Human neural progenitors derived from pluripotent embryonic stem cells and propagated in adherent serum-free cultures provide a fate restricted renewable source for quick production of neural cells; however, such cells are highly refractive to astrocytogenesis and show a strong neurogenic bias, similar to neural progenitors from the early embryonic central nervous system (CNS). We found that several astrocytic genes are hypermethylated in such progenitors potentially preventing generation of astrocytes and leading to the proneuronal fate of these progenitors. However, epigenetic modification by Azacytidine (Aza-C) and Trichostatin A (TSA), with concomitant signaling from BMP2 and LIF in neural progenitor cultures shifts this bias, leading to expression of astrocytic markers as early as 5days of differentiation, with near complete suppression of neuronal differentiation.

Images: Morphology and gene expression after 15 and 30 days of differentiation of cells with astrocytic treatment. Bright field images of hNP cells differentiated (A) with or (B) without astrocytic treatment. A and B compare morphology of cultured cells in treated vs. untreated differentiation at 15 days. Treated and untreated cells were cryopreserved at d6 and subsequently thawed and cultured for an additional 9 days. Flow cytometry analysis to determine percent of GFAP+ and S100B+ cells at d15 of differentiation. Data is presented as histograms for (C) GFAP and (D) S100B with corresponding immunoreactive cells in insets from a parallel culture. Immunocytochemistry detects expression of (E) GFAP with S100B (inset showing distinct staining for both markers), (F) GFAP with GLAST, and (G) GFAP with ALDH1L1 at d30 of differentiation.

The Protocol:  For astrocytic differentiation of hNP cells, neuronal differentiation media were supplemented with BMP2 (20 ng/mL) and combinations of Aza-C and TSA; Aza-C (500 nM), TSA (100 nM) and BMP2 (20 ng/mL) for 2 days, with one complete media change in between, followed by differentiation media supplemented with BMP2 but not with Aza-C or TSA. Cells were harvested prior to analysis at 5, 15 or 30 days of treatment or for cryopreservation at d6 or d10 of differentiation. For cryopreservation, cells were dissociated with Accutase™ and frozen in differentiation media containing10% DMSO. Viability was assessed at 30 days in Aza-C and TSA treated cultures by trypan blue exclusion, and datawas acquired using a Cellometer Auto T4® (Nexcelom Biosciences).

I will keep you updated on new differentiation protocols for our potent, pure and widely used hNP1 Human Neural Progenitors to new phenotypes.