We found that at both fetal and adult stages, human astrocytes responded robustly to ATP (Figure 3A, C, E). == Physique 3. brain. == Intro == Constituting about 40% of all cells in the human brain, astrocytes have long been classified because mere passive support cells. Recent work, however , offers demonstrated that murine astrocytes play many active roles and they are critical for the development and function from the central nervous system (CNS) (Allen and Barres, 2009; Chung et al., 2015; Clarke and Barres, 2013; Hamilton and Attwell, 2010; Haydon and Nedergaard, 2014; Khakh and McCarthy, 2015; Molofsky et al., 2012). For example , purified neurons in culture possess little ability to form functional synapses, which are powerfully promoted by astrocytes (Allen et al., 2012; Christopherson et al., 2005; Kucukdereli et al., 2011; Ullian et al., 2001). Murine astrocytes are not only important for the formation and function of synapses, but are also essential for the phagocytic elimination of synapses and the refinement of developing neural circuits (Chung et al., 2013). Since synapse formation, function, and elimination are important processes occurring during learning and memory space, astrocytes are postulated to be an indispensible component in CNS plasticity. Additionally , murine astrocytes are required for neurotransmitter recycling (Rothstein et al., 1996), extracellular potassium homeostasis (Kuffler et al., 1966), regulation of blood flow (Attwell et al., 2010; Mulligan and Phloroglucinol MacVicar, 2004; Zonta et al., 2003), and providing energy substrates for neurons (Pellerin and Magistretti, 1994). Considering their central role in CNS physiology, it is not surprising that astrocyte dysfunction has been exhibited or implicated in nearly all neurological disorders (Molofsky et al., 2012). Currently, the extent of our understanding of astrocyte physiology in health and disease is almost entirely restricted Phloroglucinol to observations in murine models, but how primary human and murine astrocytes compare at molecular and functional levels remains mainly unknown. Observational studies from postmortem human being tissues possess revealed that human being astrocytes are much larger and more complex than their murine counterparts (Oberheim et al., 2006, 2009). More recently, transplantation of human being glial progenitors into mouse brains has been shown to improve learning and memory space (Han et al., 2013). These observations raise questions about how murine astrocyte physiology and function might extend to humans. Exist distinct properties of human being astrocytes that contribute to human being intelligence and Phloroglucinol cognition? Can we extend findings about astrocyte pathology in neurological disorders from mouse and rat studies to develop effective therapeutic approaches in humans? A Phloroglucinol major hurdle in addressing these issues is the lack of a method to severly purify human being astrocytes and culture them in chemically-defined conditions. Current purification methods for human astrocytes require culturing dissociated nervous tissue in serum for days to weeks (McCarthy and de Vellis, 1980). In vivo, however , quiescent astrocytes do not contact serum except upon injury and blood-brain-barrier break down, andin vitroexposure to serum has been shown to induce irreversible reactive changes in astrocytes (Foo et al., 2011; Zamanian et al., 2012). Moreover, since serum-selection methods require a number of proliferating astrocyte progenitors, these protocols do not work efficiently to purify fully developed astrocytes from adult human Hmox1 being brains. Because of these limitations, the transcriptome profile of fully developed resting human being astrocytes has remained difficult to determine. The method we present the following is an immunopanning-based technique that utilizes an antibody targeted against HepaCAM (or GlialCAM), a surface protein expressed by human astrocytes, to generate purified (> 95%) cultures of primary human being astrocytes. Phloroglucinol With this method, we acutely purified astrocytes from over twenty fetal, juvenile, and adult human topics, and then performed transcriptome profiling and functional studies to compare developmental and interspecies differences. We additionally purified each of the major CNS cell types and generated a user-friendly searchable online database to enable dissemination of human being cell type specific gene expression data to the greater neuroscience community (http://www.BrainRNAseq.org). == Results == == Acute purification and serum-free culture of fetal and fully developed human astrocytes == We obtained juvenile (818 years old) and adult (2163 years old) human brain cells samples from patients undergoing neurological surgeries with knowledgeable consent under a Stanford University Institutional Review Board approved protocol. The samples utilized in this study (except intended for the data shown inFigures 5and6for epilepsy and glioblastoma) were small pieces of healthy temporary lobe cortices that were resected to gain access to much deeper epileptic hippocampi (Figure 1A). In each of these cases, the temporal lobe cortex that was removed was regarded as normal based upon Magnetic Resonance Imaging (MRI), Electroencephalogram (EEG) studies, and pathological examination. Detailed information on patient diagnoses is listed inTable S1. We worked closely with the surgeons to minimize the time from cells.