Expression and function of system N glutamine transporters (SN1/SN2 or SNAT3/SNAT5) in retinal ganglion cells

Nagavedi S. Umapathy, Ying Dun, Pamela M. Martin, Jennifer N. Duplantier, Penny Roon, Puttur Prasad, Sylvia B. Smith, Vadivel Ganapathy

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

PURPOSE. Glutamine transport is essential for the glutamate-glutamine cycle, which occurs between neurons and glia. System N, consisting of SN1 (SNAT3) and SN2 (SNAT5), is the principal mediator of glutamine transport in retinal Müller cells. Mediators of glutamine transport in retinal ganglion cells were investigated. METHODS. The relative contributions of various transport systems for glutamine uptake (systems N, A, L, y+L, ASCT, and ATB 0,+) were examined in RGC-5 cells based on differential features of the individual transport systems. mRNA for the genes encoding members of these transport systems were analyzed by RT-PCR. Based on these data, SN1 and SN2 were analyzed in mouse retina, RGC-5 cells, and primary mouse ganglion cells (GCs) by in situ hybridization (ISH), immunofluorescence (IF), and Western blotting. RESULTS. Three transport systems - N, A, and L - participated in glutamine uptake in RGC-5 cells. System N was the principal contributor; systems A and L contributed considerably less. ISH and IF revealed SN1 and SN2 expression in the ganglion, inner nuclear, and photoreceptor cell layers. SN1 and SN2 colocalized with the ganglion cell marker Thy 1.2 and with the Müller cell marker vimentin, confirming their presence in both retinal cell types. SN1 and SN2 proteins were detected in primary mouse GCs. CONCLUSIONS. These findings suggest that in addition to its role in glutamine uptake in retinal glial cells, system N contributes significantly to glutamine uptake in ganglion cells and, hence, contributes to the retinal glutamate-glutamine cycle.

Original languageEnglish (US)
Pages (from-to)5151-5160
Number of pages10
JournalInvestigative Ophthalmology and Visual Science
Volume49
Issue number11
DOIs
StatePublished - Nov 1 2008

Fingerprint

Retinal Ganglion Cells
Glutamine
Ganglia
Neuroglia
In Situ Hybridization
Fluorescent Antibody Technique
Glutamic Acid
system N protein 1
Photoreceptor Cells
Vimentin
Retina
Western Blotting
Neurons
Polymerase Chain Reaction
Messenger RNA

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

Cite this

Expression and function of system N glutamine transporters (SN1/SN2 or SNAT3/SNAT5) in retinal ganglion cells. / Umapathy, Nagavedi S.; Dun, Ying; Martin, Pamela M.; Duplantier, Jennifer N.; Roon, Penny; Prasad, Puttur; Smith, Sylvia B.; Ganapathy, Vadivel.

In: Investigative Ophthalmology and Visual Science, Vol. 49, No. 11, 01.11.2008, p. 5151-5160.

Research output: Contribution to journalArticle

@article{535401a4ff8d4f6298f114872cca4baa,
title = "Expression and function of system N glutamine transporters (SN1/SN2 or SNAT3/SNAT5) in retinal ganglion cells",
abstract = "PURPOSE. Glutamine transport is essential for the glutamate-glutamine cycle, which occurs between neurons and glia. System N, consisting of SN1 (SNAT3) and SN2 (SNAT5), is the principal mediator of glutamine transport in retinal M{\"u}ller cells. Mediators of glutamine transport in retinal ganglion cells were investigated. METHODS. The relative contributions of various transport systems for glutamine uptake (systems N, A, L, y+L, ASCT, and ATB 0,+) were examined in RGC-5 cells based on differential features of the individual transport systems. mRNA for the genes encoding members of these transport systems were analyzed by RT-PCR. Based on these data, SN1 and SN2 were analyzed in mouse retina, RGC-5 cells, and primary mouse ganglion cells (GCs) by in situ hybridization (ISH), immunofluorescence (IF), and Western blotting. RESULTS. Three transport systems - N, A, and L - participated in glutamine uptake in RGC-5 cells. System N was the principal contributor; systems A and L contributed considerably less. ISH and IF revealed SN1 and SN2 expression in the ganglion, inner nuclear, and photoreceptor cell layers. SN1 and SN2 colocalized with the ganglion cell marker Thy 1.2 and with the M{\"u}ller cell marker vimentin, confirming their presence in both retinal cell types. SN1 and SN2 proteins were detected in primary mouse GCs. CONCLUSIONS. These findings suggest that in addition to its role in glutamine uptake in retinal glial cells, system N contributes significantly to glutamine uptake in ganglion cells and, hence, contributes to the retinal glutamate-glutamine cycle.",
author = "Umapathy, {Nagavedi S.} and Ying Dun and Martin, {Pamela M.} and Duplantier, {Jennifer N.} and Penny Roon and Puttur Prasad and Smith, {Sylvia B.} and Vadivel Ganapathy",
year = "2008",
month = "11",
day = "1",
doi = "10.1167/iovs.08-2245",
language = "English (US)",
volume = "49",
pages = "5151--5160",
journal = "Investigative Ophthalmology and Visual Science",
issn = "0146-0404",
publisher = "Association for Research in Vision and Ophthalmology Inc.",
number = "11",

}

TY - JOUR

T1 - Expression and function of system N glutamine transporters (SN1/SN2 or SNAT3/SNAT5) in retinal ganglion cells

AU - Umapathy, Nagavedi S.

AU - Dun, Ying

AU - Martin, Pamela M.

AU - Duplantier, Jennifer N.

AU - Roon, Penny

AU - Prasad, Puttur

AU - Smith, Sylvia B.

AU - Ganapathy, Vadivel

PY - 2008/11/1

Y1 - 2008/11/1

N2 - PURPOSE. Glutamine transport is essential for the glutamate-glutamine cycle, which occurs between neurons and glia. System N, consisting of SN1 (SNAT3) and SN2 (SNAT5), is the principal mediator of glutamine transport in retinal Müller cells. Mediators of glutamine transport in retinal ganglion cells were investigated. METHODS. The relative contributions of various transport systems for glutamine uptake (systems N, A, L, y+L, ASCT, and ATB 0,+) were examined in RGC-5 cells based on differential features of the individual transport systems. mRNA for the genes encoding members of these transport systems were analyzed by RT-PCR. Based on these data, SN1 and SN2 were analyzed in mouse retina, RGC-5 cells, and primary mouse ganglion cells (GCs) by in situ hybridization (ISH), immunofluorescence (IF), and Western blotting. RESULTS. Three transport systems - N, A, and L - participated in glutamine uptake in RGC-5 cells. System N was the principal contributor; systems A and L contributed considerably less. ISH and IF revealed SN1 and SN2 expression in the ganglion, inner nuclear, and photoreceptor cell layers. SN1 and SN2 colocalized with the ganglion cell marker Thy 1.2 and with the Müller cell marker vimentin, confirming their presence in both retinal cell types. SN1 and SN2 proteins were detected in primary mouse GCs. CONCLUSIONS. These findings suggest that in addition to its role in glutamine uptake in retinal glial cells, system N contributes significantly to glutamine uptake in ganglion cells and, hence, contributes to the retinal glutamate-glutamine cycle.

AB - PURPOSE. Glutamine transport is essential for the glutamate-glutamine cycle, which occurs between neurons and glia. System N, consisting of SN1 (SNAT3) and SN2 (SNAT5), is the principal mediator of glutamine transport in retinal Müller cells. Mediators of glutamine transport in retinal ganglion cells were investigated. METHODS. The relative contributions of various transport systems for glutamine uptake (systems N, A, L, y+L, ASCT, and ATB 0,+) were examined in RGC-5 cells based on differential features of the individual transport systems. mRNA for the genes encoding members of these transport systems were analyzed by RT-PCR. Based on these data, SN1 and SN2 were analyzed in mouse retina, RGC-5 cells, and primary mouse ganglion cells (GCs) by in situ hybridization (ISH), immunofluorescence (IF), and Western blotting. RESULTS. Three transport systems - N, A, and L - participated in glutamine uptake in RGC-5 cells. System N was the principal contributor; systems A and L contributed considerably less. ISH and IF revealed SN1 and SN2 expression in the ganglion, inner nuclear, and photoreceptor cell layers. SN1 and SN2 colocalized with the ganglion cell marker Thy 1.2 and with the Müller cell marker vimentin, confirming their presence in both retinal cell types. SN1 and SN2 proteins were detected in primary mouse GCs. CONCLUSIONS. These findings suggest that in addition to its role in glutamine uptake in retinal glial cells, system N contributes significantly to glutamine uptake in ganglion cells and, hence, contributes to the retinal glutamate-glutamine cycle.

UR - http://www.scopus.com/inward/record.url?scp=56149091597&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=56149091597&partnerID=8YFLogxK

U2 - 10.1167/iovs.08-2245

DO - 10.1167/iovs.08-2245

M3 - Article

C2 - 18689705

AN - SCOPUS:56149091597

VL - 49

SP - 5151

EP - 5160

JO - Investigative Ophthalmology and Visual Science

JF - Investigative Ophthalmology and Visual Science

SN - 0146-0404

IS - 11

ER -