RT Journal Article
T1 Expression of Gls and Gls2 glutaminase isoforms in astrocytes
A1 Cardona, Carolina
A1 Sánchez-Mejías, Elisabeth
A1 Dávila-Cansino, José Carlos
A1 Martín-Rufián, Mercedes
A1 Campos-Sandoval, José Ángel
A1 Vitorica Ferrández, Javier
A1 Alonso-Carrión, Francisco José
A1 Mates-Sánchez, José Manuel
A1 Segura-Checa, Juan Antonio
A1 Norenberg, Michael
A1 Rama Rao, Kakulavarapu
A1 Jayakumar, Arumugan
A1 Gutiérrez-Pérez, Antonia
A1 Márquez-Gómez, Javier
K1 Glutaminasa
K1 Neuroglia
AB The expression of glutaminase in glial cells has been a controversial issue and matter of debate for many years. Actually, glutaminaseis essentially considered as a neuronal marker in brain. Astrocytes are endowed with efficient and high capacitytransport systems to recapture synaptic glutamate which seems to be consistent with the absence of glutaminase in theseglial cells. In this work, a comprehensive study was devised to elucidate expression of glutaminase in neuroglia and, moreconcretely, in astrocytes. Immunocytochemistry in rat and human brain tissues employing isoform-specific antibodies revealedexpression of both Gls and Gls2 glutaminase isozymes in glutamatergic and GABAergic neuronal populations as well as inastrocytes. Nevertheless, there was a different subcellular distribution: Gls isoform was always present in mitochondria whileGls2 appeared in two different locations, mitochondria and nucleus. Confocal microscopy and double immunofluorescencelabeling in cultured astrocytes confirmed the same pattern previously seen in brain tissue samples. Astrocytic glutaminaseexpression was also assessed at the mRNA level, real-time quantitative RT-PCR detected transcripts of four glutaminase isozymesbut with marked differences on their absolute copy number: the predominance of Gls isoforms over Gls2 transcriptswas remarkable (ratio of 144:1). Finally, we proved that astrocytic glutaminase proteins possess enzymatic activity by in situactivity staining: concrete populations of astrocytes were labeled in the cortex, cerebellum and hippocampus of rat braindemonstrating functional catalytic activity. These results are relevant for the stoichiometry of the Glu/Gln cycle at the tripartitesynapse and suggest novel functions for these classical metabolic enzymes.
PB Wiley
YR 2015
FD 2015
LK https://hdl.handle.net/10630/33024
UL https://hdl.handle.net/10630/33024
LA eng
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 20 ene 2026