A Transcriptome Database for Astrocytes, Neurons, and Oligodendrocytes: A New Resource for Understanding Brain Development and Function

Abstract

Understanding the cell-cell interactions that control CNS development and function has long been limited by the lack of methods to cleanly separate neural cell types. Here we describe methods for the prospective isolation and purification of astrocytes, neurons, and oligodendrocytes from developing and mature mouse forebrain. We used FACS (fluorescent-activated cell sorting) to isolate astrocytes from transgenic mice that express enhanced green fluorescent protein (EGFP) under the control of an S100␤ promoter. Using Affymetrix GeneChip Arrays, we then created a transcriptome database of the expression levels of Ͼ20,000 genes by gene profiling these three main CNS neural cell types at various postnatal ages between postnatal day 1 (P1) and P30. This database provides a detailed global characterization and comparison of the genes expressed by acutely isolated astrocytes, neurons, and oligodendrocytes. We found that Aldh1L1 is a highly specific antigenic marker for astrocytes with a substantially broader pattern of astrocyte expression than the traditional astrocyte marker GFAP. Astrocytes were enriched in specific metabolic and lipid synthetic pathways, as well as the draper/Megf10 and Mertk/ integrin ␣ v ␤ 5 phagocytic pathways suggesting that astrocytes are professional phagocytes. Our findings call into question the concept of a "glial" cell class as the gene profiles of astrocytes and oligodendrocytes are as dissimilar to each other as they are to neurons. This transcriptome database of acutely isolated purified astrocytes, neurons, and oligodendrocytes provides a resource to the neuroscience community by providing improved cell-type-specific markers and for better understanding of neural development, function, and disease.

Astrocyte reactivity after brain injury—: The role of galectins 1 and 3

“…As expected, a large number of common genes were found to be expressed in reactive and nonreactive astrocytes (Fig. 3A, B; see also Beckervordersandforth et al, 2010; Cahoy et al, 2008; Zamanian et al, 2012; Zhang et al, 2014). Conversely, genes specific for neurons, microglia, or oligodendroglia were consistently very low, confirming the selective sorting of astrocytes (Fig.…”

“…Conversely, genes specific for neurons, microglia, or oligodendroglia were consistently very low, confirming the selective sorting of astrocytes (Fig. 3B; see also Cahoy et al, 2008; Zhang et al, 2014). Notably, reactive astrocytes showed significantly lower expression of most astrocyte‐specific genes (selected as astrocyte‐specific from Cahoy et al 2008, Zhang et al 2014), except for Aldh1l1 and GFAP (Fig.…”

“…3B; see also Cahoy et al, 2008; Zhang et al, 2014). Notably, reactive astrocytes showed significantly lower expression of most astrocyte‐specific genes (selected as astrocyte‐specific from Cahoy et al 2008, Zhang et al 2014), except for Aldh1l1 and GFAP (Fig. 3B).…”

“…1C, D). Aldh1L1 is expressed in astrocytes in young rodent tissue (Cahoy et al, 2008), but has been suggested to decrease during ageing (Yang et al, 2011). In the 2–3‐months old Aldh1L1‐eGFP mice, we found virtually all astrocytes labeled by S100β (Fig.…”

Astroglia as a cellular target for neuroprotection and treatment of neuro‐psychiatric disorders

“…In contrast to the mixed distribution of GPR37, GPR37L1 is highly expressed in astrocytes, with in situ hybridization revealing greatest density of GPR37L1 within the Bergmann glia of the cerebellum (Valdenaire et al, 1998). Microarray studies reported more than 100 times higher expression of GPR37L1 in rat and mice astrocytes compared with neurons (Cahoy et al, 2008; Lovatt et al, 2007; Zhang et al, 2014). GPR37L1 is also expressed in oligodendrocytes (Zhang et al, 2014).…”