Differential regulation of C-terminal splice variants of the glutamate transporter GLT-1 by tumor necrosis factor-alpha in primary cultures of astrocytes

Focant, Marylène C.;Goursaud, Stéphanie;Nizet, Yannick;Hermans, Emmanuel
(2011) Neurochemistry International : the journal for the publication of cellular and molecular aspects of neurochemistry — Vol. 58, n° 7, p. 751-758 (2011)

Files

Focant2011.pdf
  • Open Access
  • Adobe PDF
  • 788.32 KB

Details

Authors
  • Focant, Marylène C.UCLouvain
    Author
  • Goursaud, StéphanieUCLouvain
    Author
  • Nizet, YannickUCLouvain
    Author
  • Author
Abstract
The high-affinity glutamate transporter GLT-1 plays a key role in the control of the glutamate homeostasis in the central nervous system and protects neurons against excitotoxicity. Splice variants of the original transcript have been identified and their involvement in neurodegenerative disorders has been proposed. However, the functions and the regulations of these isoforms remain unclear. In this study, we focused our interest on the expression of two C-terminal splice variants of GLT-1 (GLT-1a and b) in primary astrocyte cultures exposed to distinct chemical environments. While GLT-1a and GLT-1b mRNAs were both increased in response to treatment with N(6),2'-O-dibutyryladenosine 3',5'-cyclic monophosphate (dBcAMP), the culture supplement G5 or tumor necrosis factor-alpha (TNF-α), the regulation of GLT-1b appeared quicker and was more pronounced. Besides, using validated antibodies, we evidenced a differential regulation of the two proteins in cells exposed to TNF-α. Thus, while dBcAMP and the G5 supplement stimulated the expression of both isoforms at 3 and 7 days, a transient upregulation of GLT-1a was induced by TNF-α, which contrasts with the sustained induction of the GLT-1b isoform. These results shed light on the complex influence of the pro-inflammatory cytokine TNF-α on GLT-1a mRNA and protein expression and on the necessity to distinctly consider the GLT-1 isoforms with appropriate tools in studies addressing the regulation of glutamate transporters.
Affiliations

Citations

Focant, M. C., Goursaud, S., Nizet, Y., & Hermans, E. (2011). Differential regulation of C-terminal splice variants of the glutamate transporter GLT-1 by tumor necrosis factor-alpha in primary cultures of astrocytes. Neurochemistry International : the journal for the publication of cellular and molecular aspects of neurochemistry, 58(7), 751-758. https://doi.org/10.1016/j.neuint.2011.02.023 (Original work published 2011)