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Rosiewicz KS, Crowley T, Saher G, Kerkering J, Alisch M, Siffrin V. Comparison of RNA isolation procedures for analysis of adult murine brain and spinal cord astrocytes. J Neurosci Methods 2020; 333:108545. [PMID: 31821821 DOI: 10.1016/j.jneumeth.2019.108545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/25/2019] [Accepted: 12/06/2019] [Indexed: 11/23/2022]
Abstract
BACKGROUND Molecular analyses of cell populations and single cells have been instrumental in the advancement of our understanding of the physiology and pathologic processes of the nervous system. However, the limitation of these methods is the dependence on a gentle, efficient and specific enrichment procedure for the target cell population. In particular, this has been challenging for tightly interconnected cells, for example central nervous system (CNS) endogenous cells such as astrocytes. NEW METHOD Here we adopted one of the most common methods of cell extraction, namely, enzymatic tissue digestion followed by fluorescence-activated cell sorting (FACS) of individual cells. We evaluated different enzymatic/mechanical tissue dissociation procedures and analyzed different astrocyte lineage transgenic models. Furthermore, we compared the cell extraction efficiency from spinal cord vs. brain. RESULTS Enzymatic digestion of CNS tissue of Glast-CreERT2x tdTomatofl/fl or Aldh1l1-CreERT2x tdTomatofl/fl followed by FACS resulted in highly purified astrocytes. Automated tissue digestion strongly improved the isolated cell numbers. Aldh1l1-CreERT2 identified more astrocytes than Glast-CreERT2; isolation from brain yields higher numbers than from spinal cord. COMPARISON WITH EXISTING METHODS We compared the efficiency and purity of the enzymatic dissociation/FACS approach with a more modern procedure consisting of tissue homogenization followed by translating ribosome affinity purification (TRAP). CONCLUSION We found that both methods result in highly enriched astrocytic RNA. However, only TRAP isolation resulted in reliably detectable RNA concentrations from spinal cord tissue on a single animal level. Depending on the aim of the study both methods have advantages and disadvantages but both are acceptable for astrocytic RNA analysis.
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Berger JM, Singh P, Khrimian L, Morgan DA, Chowdhury S, Arteaga-Solis E, Horvath TL, Domingos AI, Marsland AL, Yadav VK, Rahmouni K, Gao XB, Karsenty G. Mediation of the Acute Stress Response by the Skeleton. Cell Metab 2019; 30:890-902.e8. [PMID: 31523009 PMCID: PMC6834912 DOI: 10.1016/j.cmet.2019.08.012] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 06/26/2019] [Accepted: 08/12/2019] [Indexed: 12/19/2022]
Abstract
We hypothesized that bone evolved, in part, to enhance the ability of bony vertebrates to escape danger in the wild. In support of this notion, we show here that a bone-derived signal is necessary to develop an acute stress response (ASR). Indeed, exposure to various types of stressors in mice, rats (rodents), and humans leads to a rapid and selective surge of circulating bioactive osteocalcin because stressors favor the uptake by osteoblasts of glutamate, which prevents inactivation of osteocalcin prior to its secretion. Osteocalcin permits manifestations of the ASR to unfold by signaling in post-synaptic parasympathetic neurons to inhibit their activity, thereby leaving the sympathetic tone unopposed. Like wild-type animals, adrenalectomized rodents and adrenal-insufficient patients can develop an ASR, and genetic studies suggest that this is due to their high circulating osteocalcin levels. We propose that osteocalcin defines a bony-vertebrate-specific endocrine mediation of the ASR.
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Affiliation(s)
- Julian Meyer Berger
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA; Program in Microbiology, Immunology and Infection, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Parminder Singh
- Metabolic Research Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Lori Khrimian
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Donald A Morgan
- Department of Pharmacology, University of Iowa and Veteran Health Care System, Iowa City, IA 52242, USA
| | - Subrata Chowdhury
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Emilio Arteaga-Solis
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA; Division of Pediatric Pulmonary, Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Tamas L Horvath
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Ana I Domingos
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Anna L Marsland
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Vijay Kumar Yadav
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA; Metabolic Research Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa and Veteran Health Care System, Iowa City, IA 52242, USA
| | - Xiao-Bing Gao
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Gerard Karsenty
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA.
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