Journal
NEUROCHEMISTRY INTERNATIONAL
Volume 118, Issue -, Pages 225-232Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.neuint.2018.07.001
Keywords
Astrocytes; Glutamine; SN1 (SNAT3); Glutamine release; Ammonia; PKC
Categories
Funding
- Polish-Norwegian Research Program [Pol-Nor/196190/23/2013]
Ask authors/readers for more resources
SN1, a system N amino acid transporter specific for astrocytes, is mainly responsible for export of newly synthesized L-glutamine from the cells. Astrocytic retention of L-glutamine which plays a critical role in ammonia induced astrocytic swelling resulting in brain edema, could be tentatively attributed to the impaired L-glutamine export from astrocytes. The present study demonstrates that treatment of cultured mouse cortical astrocytes for 24 h with 5 mM ammonium chloride (ammonia) inhibits the system N-mediated L-glutamine transport out of the cell, and that this inhibition is related to the reduced presence of the SN1 transporter on the cell membrane. Ammonia decreased total protein kinase C (PKC) activity in the absence but not in the presence of PKC activator, phorbol 12-myristate 13-acetate (PMA), and activation of PKC by PMA reversed both the ammonia-induced decrease of system N-mediated L-glutamine release and ammonia-induced SN1 deficit in the membrane fraction. However, while ammonia did not change the protein level of PKC alpha isoform, it decreased the protein content of PKC delta. Moreover, ammonia treatment increased the cell surface expression of SN1 in cells with silenced PKC alpha and PKC8 delta. Silencing of PKC delta abrogated the decrease of system N (SN1)-mediated L-glutamine release by ammonia. The results implicate the involvement of PKCS in the inhibition of SN1 membrane expression and activity by ammonia.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available