Silencing of Transcription Factor Sp1 Promotes SN1 Transporter Regulation by Ammonia in Mouse Cortical Astrocytes

Overview

Journal Int J Mol Sci

Publisher MDPI

Specialties Biochemistry
Chemistry
Molecular Biology

Date 2019 Jan 13

PMID 30634395

Citations 5

Authors

Katarzyna Dabrowska

Magdalena Zielinska

Affiliations

Soon will be listed here.

Abstract

The involvement of the astrocytic SN1 (SNAT3) transporter in ammonia-induced l-glutamine retention was recently documented in mouse-cultured astrocytes. Here we investigated the involvement of specificity protein 1 (Sp1) transcription factor in SN1 regulation in ammonium chloride ("ammonia")-treated astrocytes. Sp1 expression and its cellular localization were determined using real-time qPCR, Western blot, and confocal microscopy. Sp1 binding to promoter was analyzed by chromatin immunoprecipitation. The role of Sp1 in SN1 expression and SN1-mediated [³H]glutamine uptake in ammonia-treated astrocytes was verified using siRNA and mithramycin A. The involvement of protein kinase C (PKC) isoforms in Sp1 level/phosphorylation status was verified using siRNA technology. Sp1 translocation to the nuclei and its enhanced binding to the promoter, along with Sp1 dependence of system N-mediated [³H]glutamine uptake, were observed in astrocytes upon ammonia exposure. Ammonia decreased the level of phosphorylated Sp1, and the effect was reinforced by long-term incubation with PKC modulator, phorbol 12-myristate 13-acetate, which is a treatment likely to dephosphorylate Sp1. Furthermore, silencing of the PKCδ isoform appears to enhance the ammonia effect on the Sp1 level. Collectively, the results demonstrate the regulatory role of Sp1 in regulation of SN1 expression and activity in ammonia-treated astrocytes and implicate altered Sp1 phosphorylation status in this capacity.

Citing Articles

HIV Nef Expression Down-modulated GFAP Expression and Altered Glutamate Uptake and Release and Proliferation in Astrocytes.

Wilson K, He J Aging Dis. 2023; 14(1):152-169.

PMID: 36818564 PMC: 9937695. DOI: 10.14336/AD.2022.0712.

Dysregulation of Astrocytic Glutamine Transport in Acute Hyperammonemic Brain Edema.

Zielinska M, Albrecht J, Popek M Front Neurosci. 2022; 16:874750.

PMID: 35733937 PMC: 9207324. DOI: 10.3389/fnins.2022.874750.

The Role of Nrf2 Transcription Factor and Sp1-Nrf2 Protein Complex in Glutamine Transporter SN1 Regulation in Mouse Cortical Astrocytes Exposed to Ammonia.

Dabrowska K, Skowronska K, Popek M, Albrecht J, Zielinska M Int J Mol Sci. 2021; 22(20).

PMID: 34681893 PMC: 8538223. DOI: 10.3390/ijms222011233.

Amino Acids Transport and Metabolism 2.0.

Scalise M, Indiveri C Int J Mol Sci. 2020; 21(4).

PMID: 32059365 PMC: 7072841. DOI: 10.3390/ijms21041212.

Understanding the Role of the Transcription Factor Sp1 in Ovarian Cancer: from Theory to Practice.

Vellingiri B, Iyer M, Subramaniam M, Jayaramayya K, Siama Z, Giridharan B Int J Mol Sci. 2020; 21(3).

PMID: 32050495 PMC: 7038193. DOI: 10.3390/ijms21031153.

References

Philipsen S, Suske G . A tale of three fingers: the family of mammalian Sp/XKLF transcription factors. Nucleic Acids Res. 1999; 27(15):2991-3000. PMC: 148522. DOI: 10.1093/nar/27.15.2991. View

Tretiakova A, Steplewski A, Johnson E, Khalili K, Amini S . Regulation of myelin basic protein gene transcription by Sp1 and Puralpha: evidence for association of Sp1 and Puralpha in brain. J Cell Physiol. 1999; 181(1):160-8. DOI: 10.1002/(SICI)1097-4652(199910)181:1<160::AID-JCP17>3.0.CO;2-H. View

Blei A, Larsen F . Pathophysiology of cerebral edema in fulminant hepatic failure. J Hepatol. 1999; 31(4):771-6. DOI: 10.1016/s0168-8278(99)80361-4. View

Zieminska E, Dolinska M, Lazarewicz J, Albrecht J . Induction of permeability transition and swelling of rat brain mitochondria by glutamine. Neurotoxicology. 2000; 21(3):295-300. View

Haussinger D, Kircheis G, Fischer R, Schliess F, Vom Dahl S . Hepatic encephalopathy in chronic liver disease: a clinical manifestation of astrocyte swelling and low-grade cerebral edema?. J Hepatol. 2000; 32(6):1035-8. DOI: 10.1016/s0168-8278(00)80110-5. View

Du X, Edelstein D, Rossetti L, Fantus I, Goldberg H, Ziyadeh F . Hyperglycemia-induced mitochondrial superoxide overproduction activates the hexosamine pathway and induces plasminogen activator inhibitor-1 expression by increasing Sp1 glycosylation. Proc Natl Acad Sci U S A. 2000; 97(22):12222-6. PMC: 17322. DOI: 10.1073/pnas.97.22.12222. View

Pearson G, Robinson F, Beers Gibson T, Xu B, Karandikar M, Berman K . Mitogen-activated protein (MAP) kinase pathways: regulation and physiological functions. Endocr Rev. 2001; 22(2):153-83. DOI: 10.1210/edrv.22.2.0428. View

Black A, Black J, Azizkhan-Clifford J . Sp1 and krüppel-like factor family of transcription factors in cell growth regulation and cancer. J Cell Physiol. 2001; 188(2):143-60. DOI: 10.1002/jcp.1111. View

Warskulat U, Kreuels S, Muller H, Haussinger D . Identification of osmosensitive and ammonia-regulated genes in rat astrocytes by Northern blotting and differential display reverse transcriptase-polymerase chain reaction. J Hepatol. 2001; 35(3):358-66. DOI: 10.1016/s0168-8278(01)00149-0. View

10.

Fojas de Borja P, Collins N, Du P, Azizkhan-Clifford J, Mudryj M . Cyclin A-CDK phosphorylates Sp1 and enhances Sp1-mediated transcription. EMBO J. 2001; 20(20):5737-47. PMC: 125670. DOI: 10.1093/emboj/20.20.5737. View

11.

Bai G, Rama Rao K, Murthy C, Panickar K, Jayakumar A, Norenberg M . Ammonia induces the mitochondrial permeability transition in primary cultures of rat astrocytes. J Neurosci Res. 2001; 66(5):981-91. DOI: 10.1002/jnr.10056. View

12.

Milanini-Mongiat J, Pouyssegur J, Pages G . Identification of two Sp1 phosphorylation sites for p42/p44 mitogen-activated protein kinases: their implication in vascular endothelial growth factor gene transcription. J Biol Chem. 2002; 277(23):20631-9. DOI: 10.1074/jbc.M201753200. View

13.

Pithon-Curi T, Trezena A, Tavares-Lima W, Curi R . Evidence that glutamine is involved in neutrophil function. Cell Biochem Funct. 2002; 20(2):81-6. DOI: 10.1002/cbf.954. View

14.

Suarez I, Bodega G, Fernandez B . Glutamine synthetase in brain: effect of ammonia. Neurochem Int. 2002; 41(2-3):123-42. DOI: 10.1016/s0197-0186(02)00033-5. View

15.

Boulland J, Osen K, Levy L, Danbolt N, Edwards R, Storm-Mathisen J . Cell-specific expression of the glutamine transporter SN1 suggests differences in dependence on the glutamine cycle. Eur J Neurosci. 2002; 15(10):1615-31. DOI: 10.1046/j.1460-9568.2002.01995.x. View

16.

Song G, Dhodda V, Blei A, Dempsey R, Raghavendra Rao V . GeneChip analysis shows altered mRNA expression of transcripts of neurotransmitter and signal transduction pathways in the cerebral cortex of portacaval shunted rats. J Neurosci Res. 2002; 68(6):730-7. DOI: 10.1002/jnr.10268. View

17.

Cynober L . Plasma amino acid levels with a note on membrane transport: characteristics, regulation, and metabolic significance. Nutrition. 2002; 18(9):761-6. DOI: 10.1016/s0899-9007(02)00780-3. View

18.

Warskulat U, Gorg B, Bidmon H, Muller H, Schliess F, Haussinger D . Ammonia-induced heme oxygenase-1 expression in cultured rat astrocytes and rat brain in vivo. Glia. 2002; 40(3):324-36. DOI: 10.1002/glia.10128. View

19.

Butterworth R . Pathophysiology of hepatic encephalopathy: a new look at ammonia. Metab Brain Dis. 2003; 17(4):221-7. DOI: 10.1023/a:1021989230535. View

20.

Roux P, Blenis J . ERK and p38 MAPK-activated protein kinases: a family of protein kinases with diverse biological functions. Microbiol Mol Biol Rev. 2004; 68(2):320-44. PMC: 419926. DOI: 10.1128/MMBR.68.2.320-344.2004. View