Expression of Gls and Gls2 glutaminase isoforms in astrocytes

Carolina Cardona, Elisabeth Sánchez-Mejías, José C. Dávila, Mercedes Martín-Rufián, José A. Campos-Sandoval, Javier Vitorica, Francisco J. Alonso, José M. Matés, Juan A. Segura, Michael D Norenberg, Kakulavarapu V. Rama Rao, Arumugan R. Jayakumar, Antonia Gutiérrez, Javier Márquez

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

The expression of glutaminase in glial cells has been a controversial issue and matter of debate for many years. Actually, glutaminase is essentially considered as a neuronal marker in brain. Astrocytes are endowed with efficient and high capacity transport systems to recapture synaptic glutamate which seems to be consistent with the absence of glutaminase in these glial cells. In this work, a comprehensive study was devised to elucidate expression of glutaminase in neuroglia and, more concretely, in astrocytes. Immunocytochemistry in rat and human brain tissues employing isoform-specific antibodies revealed expression of both Gls and Gls2 glutaminase isozymes in glutamatergic and GABAergic neuronal populations as well as in astrocytes. Nevertheless, there was a different subcellular distribution: Gls isoform was always present in mitochondria while Gls2 appeared in two different locations, mitochondria and nucleus. Confocal microscopy and double immunofluorescence labeling in cultured astrocytes confirmed the same pattern previously seen in brain tissue samples. Astrocytic glutaminase expression was also assessed at the mRNA level, real-time quantitative RT-PCR detected transcripts of four glutaminase isozymes but with marked differences on their absolute copy number: the predominance of Gls isoforms over Gls2 transcripts was remarkable (ratio of 144:1). Finally, we proved that astrocytic glutaminase proteins possess enzymatic activity by in situ activity staining: concrete populations of astrocytes were labeled in the cortex, cerebellum and hippocampus of rat brain demonstrating functional catalytic activity. These results are relevant for the stoichiometry of the Glu/Gln cycle at the tripartite synapse and suggest novel functions for these classical metabolic enzymes.

Original languageEnglish
Pages (from-to)365-382
Number of pages18
JournalGLIA
Volume63
Issue number3
DOIs
StatePublished - Jan 1 2015

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Glutaminase
Astrocytes
Protein Isoforms
Neuroglia
Brain
Isoenzymes
Mitochondria
Confocal Microscopy
Synapses
Cerebellum
Population
Fluorescent Antibody Technique
Real-Time Polymerase Chain Reaction
Glutamic Acid
Hippocampus
Immunohistochemistry
Staining and Labeling
Messenger RNA
Antibodies

Keywords

  • Astrocytes
  • Glial cells
  • Glutamate
  • Glutaminase
  • Glutamine
  • Mitochondrion
  • Nucleus

ASJC Scopus subject areas

  • Cellular and Molecular Neuroscience
  • Neurology

Cite this

Cardona, C., Sánchez-Mejías, E., Dávila, J. C., Martín-Rufián, M., Campos-Sandoval, J. A., Vitorica, J., ... Márquez, J. (2015). Expression of Gls and Gls2 glutaminase isoforms in astrocytes. GLIA, 63(3), 365-382. https://doi.org/10.1002/glia.22758

Expression of Gls and Gls2 glutaminase isoforms in astrocytes. / Cardona, Carolina; Sánchez-Mejías, Elisabeth; Dávila, José C.; Martín-Rufián, Mercedes; Campos-Sandoval, José A.; Vitorica, Javier; Alonso, Francisco J.; Matés, José M.; Segura, Juan A.; Norenberg, Michael D; Rama Rao, Kakulavarapu V.; Jayakumar, Arumugan R.; Gutiérrez, Antonia; Márquez, Javier.

In: GLIA, Vol. 63, No. 3, 01.01.2015, p. 365-382.

Research output: Contribution to journalArticle

Cardona, C, Sánchez-Mejías, E, Dávila, JC, Martín-Rufián, M, Campos-Sandoval, JA, Vitorica, J, Alonso, FJ, Matés, JM, Segura, JA, Norenberg, MD, Rama Rao, KV, Jayakumar, AR, Gutiérrez, A & Márquez, J 2015, 'Expression of Gls and Gls2 glutaminase isoforms in astrocytes', GLIA, vol. 63, no. 3, pp. 365-382. https://doi.org/10.1002/glia.22758
Cardona C, Sánchez-Mejías E, Dávila JC, Martín-Rufián M, Campos-Sandoval JA, Vitorica J et al. Expression of Gls and Gls2 glutaminase isoforms in astrocytes. GLIA. 2015 Jan 1;63(3):365-382. https://doi.org/10.1002/glia.22758
Cardona, Carolina ; Sánchez-Mejías, Elisabeth ; Dávila, José C. ; Martín-Rufián, Mercedes ; Campos-Sandoval, José A. ; Vitorica, Javier ; Alonso, Francisco J. ; Matés, José M. ; Segura, Juan A. ; Norenberg, Michael D ; Rama Rao, Kakulavarapu V. ; Jayakumar, Arumugan R. ; Gutiérrez, Antonia ; Márquez, Javier. / Expression of Gls and Gls2 glutaminase isoforms in astrocytes. In: GLIA. 2015 ; Vol. 63, No. 3. pp. 365-382.
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