Abstract
1. After 8 days in vitro, rat cerebellar granule cells were exposed to 1 mM gamma-aminobutyric acid (GABA) for periods of 1, 2, 4, 6, 8 and 10 days. The effect of the GABA exposure on GABAA receptor alpha 1, alpha 6 and beta 2,3 subunit protein expression and alpha 1 and alpha 6 subunit steady-state mRNA levels, was examined using Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR), respectively. 2. GABA exposure for 2 days decreased alpha 1 (35 +/- 10%, mean +/- s.e.mean), beta 2,3 (21 +/- 9%) and alpha 6 (28 +/- 10%) subunit protein expression compared to control levels. The GABA-mediated reduction in alpha 1 subunit expression after 2 days treatment was abolished in the presence of the GABAA receptor antagonist, Ru 5135 (10 microM). 3. GABA exposure for 8 days increased alpha 1 (26 +/- 10%, mean +/- s.e.mean) and beta 2,3 (56 +/- 23%) subunit protein expression over control levels, whereas alpha 6 subunit protein expression remained below control levels (by 38 +/- 10%). However, after 10 days GABA exposure, alpha 6 subunit protein expression was also increased over control levels by 65 +/- 29% (mean +/- s.e.mean). 4. GABA exposure did not change the alpha 1 or alpha 6 subunit steady-state mRNA levels over and 8 day period, nor did it alter the expression of cyclophilin mRNA over 1-8 days. 5. These results suggest that chronic GABA exposure of rat cerebellar granule cells has a bi-phasic effect on GABAA receptor subunit expression that is independent of changes to mRNA levels. Therefore, the regulation of the GABAA receptor expression by chronic agonist treatment appears to involve post-transcriptional and/or post-translational processes.
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- Baumgartner B. J., Harvey R. J., Darlison M. G., Barnes E. M., Jr Developmental up-regulation and agonist-dependent down-regulation of GABAA receptor subunit mRNAs in chick cortical neurons. Brain Res Mol Brain Res. 1994 Oct;26(1-2):9–17. doi: 10.1016/0169-328x(94)90068-x. [DOI] [PubMed] [Google Scholar]
- Beattie C. E., Siegel R. E. Developmental cues modulate GABAA receptor subunit mRNA expression in cultured cerebellar granule neurons. J Neurosci. 1993 Apr;13(4):1784–1792. doi: 10.1523/JNEUROSCI.13-04-01784.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Belhage B., Hansen G. H., Schousboe A. GABA agonist induced changes in ultrastructure and GABA receptor expression in cerebellar granule cells is linked to hyperpolarization of the neurons. Int J Dev Neurosci. 1990;8(4):473–479. doi: 10.1016/0736-5748(90)90079-h. [DOI] [PubMed] [Google Scholar]
- Belhage B., Hansen G. H., Schousboe A., Meier E. GABA agonist promoted formation of low affinity GABA receptors on cerebellar granule cells is restricted to early development. Int J Dev Neurosci. 1988;6(2):125–128. doi: 10.1016/0736-5748(88)90036-6. [DOI] [PubMed] [Google Scholar]
- Borden L. A., Farb D. H. Mechanism of gamma-aminobutyric acid/benzodiazepine receptor turnover in neuronal cells: evidence for nonlysosomal degradation. Mol Pharmacol. 1988 Sep;34(3):354–362. [PubMed] [Google Scholar]
- Bovolin P., Santi M. R., Memo M., Costa E., Grayson D. R. Distinct developmental patterns of expression of rat alpha 1, alpha 5, gamma 2S, and gamma 2L gamma-aminobutyric acidA receptor subunit mRNAs in vivo and in vitro. J Neurochem. 1992 Jul;59(1):62–72. doi: 10.1111/j.1471-4159.1992.tb08876.x. [DOI] [PubMed] [Google Scholar]
- Bovolin P., Santi M. R., Puia G., Costa E., Grayson D. Expression patterns of gamma-aminobutyric acid type A receptor subunit mRNAs in primary cultures of granule neurons and astrocytes from neonatal rat cerebella. Proc Natl Acad Sci U S A. 1992 Oct 1;89(19):9344–9348. doi: 10.1073/pnas.89.19.9344. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bristow D. R., Martin I. L. GABA preincubation of rat brain sections increases [3H]GABA binding to the GABAA receptor and compromises the modulatory interactions. Eur J Pharmacol. 1989 Nov 28;173(1):65–73. doi: 10.1016/0014-2999(89)90009-5. [DOI] [PubMed] [Google Scholar]
- Brown M. J., Bristow D. R. Molecular mechanisms of benzodiazepine-induced down-regulation of GABAA receptor alpha 1 subunit protein in rat cerebellar granule cells. Br J Pharmacol. 1996 Jul;118(5):1103–1110. doi: 10.1111/j.1476-5381.1996.tb15512.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Calkin P. A., Barnes E. M., Jr gamma-Aminobutyric acid-A (GABAA) agonists down-regulate GABAA/benzodiazepine receptor polypeptides from the surface of chick cortical neurons. J Biol Chem. 1994 Jan 14;269(2):1548–1553. [PubMed] [Google Scholar]
- Calkin P. A., Baumgartner B. J., Barnes E. M., Jr Agonist administration in ovo down-regulates cerebellar GABAA receptors in the chick embryo. Brain Res Mol Brain Res. 1994 Oct;26(1-2):18–25. doi: 10.1016/0169-328x(94)90069-8. [DOI] [PubMed] [Google Scholar]
- Cash D. J., Subbarao K. Desensitization of gamma-aminobutyric acid receptor from rat brain: two distinguishable receptors on the same membrane. Biochemistry. 1987 Dec 1;26(24):7556–7562. doi: 10.1021/bi00398a004. [DOI] [PubMed] [Google Scholar]
- Celentano J. J., Wong R. K. Multiphasic desensitization of the GABAA receptor in outside-out patches. Biophys J. 1994 Apr;66(4):1039–1050. doi: 10.1016/S0006-3495(94)80885-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chomczynski P., Sacchi N. Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal Biochem. 1987 Apr;162(1):156–159. doi: 10.1006/abio.1987.9999. [DOI] [PubMed] [Google Scholar]
- Ducić I., Caruncho H. J., Zhu W. J., Vicini S., Costa E. gamma-Aminobutyric acid gating of Cl- channels in recombinant GABAA receptors. J Pharmacol Exp Ther. 1995 Jan;272(1):438–445. [PubMed] [Google Scholar]
- Ebert B., Wafford K. A., Whiting P. J., Krogsgaard-Larsen P., Kemp J. A. Molecular pharmacology of gamma-aminobutyric acid type A receptor agonists and partial agonists in oocytes injected with different alpha, beta, and gamma receptor subunit combinations. Mol Pharmacol. 1994 Nov;46(5):957–963. [PubMed] [Google Scholar]
- Gallo V., Ciotti M. T., Coletti A., Aloisi F., Levi G. Selective release of glutamate from cerebellar granule cells differentiating in culture. Proc Natl Acad Sci U S A. 1982 Dec;79(24):7919–7923. doi: 10.1073/pnas.79.24.7919. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gao B., Fritschy J. M. Cerebellar granule cells in vitro recapitulate the in vivo pattern of GABAA-receptor subunit expression. Brain Res Dev Brain Res. 1995 Aug 28;88(1):1–16. doi: 10.1016/0165-3806(95)00062-i. [DOI] [PubMed] [Google Scholar]
- Hablitz J. J., Tehrani M. H., Barnes E. M., Jr Chronic exposure of developing cortical neurons to GABA down-regulates GABA/benzodiazepine receptors and GABA-gated chloride currents. Brain Res. 1989 Nov 6;501(2):332–338. doi: 10.1016/0006-8993(89)90650-1. [DOI] [PubMed] [Google Scholar]
- Hansen G. H., Belhage B., Schousboe A. Effect of a GABA agonist on the expression and distribution of GABAA receptors in the plasma membrane of cultured cerebellar granule cells: an immunocytochemical study. Neurosci Lett. 1991 Apr 1;124(2):162–165. doi: 10.1016/0304-3940(91)90084-7. [DOI] [PubMed] [Google Scholar]
- Hatten M. E., Liem R. K., Mason C. A. Two forms of cerebellar glial cells interact differently with neurons in vitro. J Cell Biol. 1984 Jan;98(1):193–204. doi: 10.1083/jcb.98.1.193. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hirouchi M., Ohkuma S., Kuriyama K. Muscimol-induced reduction of GABAA receptor alpha 1-subunit mRNA in primary cultured cerebral cortical neurons. Brain Res Mol Brain Res. 1992 Oct;15(3-4):327–331. doi: 10.1016/0169-328x(92)90125-u. [DOI] [PubMed] [Google Scholar]
- Häring P., Stähli C., Schoch P., Takács B., Staehelin T., Möhler H. Monoclonal antibodies reveal structural homogeneity of gamma-aminobutyric acid/benzodiazepine receptors in different brain areas. Proc Natl Acad Sci U S A. 1985 Jul;82(14):4837–4841. doi: 10.1073/pnas.82.14.4837. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Khan Z. U., Gutiérrez A., De Blas A. L. The alpha 1 and alpha 6 subunits can coexist in the same cerebellar GABAA receptor maintaining their individual benzodiazepine-binding specificities. J Neurochem. 1996 Feb;66(2):685–691. doi: 10.1046/j.1471-4159.1996.66020685.x. [DOI] [PubMed] [Google Scholar]
- Kim H. Y., Sapp D. W., Olsen R. W., Tobin A. J. GABA alters GABAA receptor mRNAs and increases ligand binding. J Neurochem. 1993 Dec;61(6):2334–2337. doi: 10.1111/j.1471-4159.1993.tb07481.x. [DOI] [PubMed] [Google Scholar]
- Kleingoor C., Wieland H. A., Korpi E. R., Seeburg P. H., Kettenmann H. Current potentiation by diazepam but not GABA sensitivity is determined by a single histidine residue. Neuroreport. 1993 Feb;4(2):187–190. doi: 10.1097/00001756-199302000-00018. [DOI] [PubMed] [Google Scholar]
- Krishek B. J., Xie X., Blackstone C., Huganir R. L., Moss S. J., Smart T. G. Regulation of GABAA receptor function by protein kinase C phosphorylation. Neuron. 1994 May;12(5):1081–1095. doi: 10.1016/0896-6273(94)90316-6. [DOI] [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Lohse M. J. Molecular mechanisms of membrane receptor desensitization. Biochim Biophys Acta. 1993 Nov 7;1179(2):171–188. doi: 10.1016/0167-4889(93)90139-g. [DOI] [PubMed] [Google Scholar]
- Lüddens H., Seeburg P. H., Korpi E. R. Impact of beta and gamma variants on ligand-binding properties of gamma-aminobutyric acid type A receptors. Mol Pharmacol. 1994 May;45(5):810–814. [PubMed] [Google Scholar]
- Maloteaux J. M., Octave J. N., Gossuin A., Laterre C., Trouet A. GABA induces down-regulation of the benzodiazepine-GABA receptor complex in the rat cultured neurons. Eur J Pharmacol. 1987 Dec 1;144(2):173–183. doi: 10.1016/0014-2999(87)90517-6. [DOI] [PubMed] [Google Scholar]
- McKernan R. M., Cox P., Gillard N. P., Whiting P. Differential expression of GABAA receptor alpha-subunits in rat brain during development. FEBS Lett. 1991 Jul 29;286(1-2):44–46. doi: 10.1016/0014-5793(91)80936-w. [DOI] [PubMed] [Google Scholar]
- McKernan R. M., Whiting P. J. Which GABAA-receptor subtypes really occur in the brain? Trends Neurosci. 1996 Apr;19(4):139–143. doi: 10.1016/s0166-2236(96)80023-3. [DOI] [PubMed] [Google Scholar]
- Mehta A. K., Ticku M. K. Chronic GABA exposure down-regulates GABA-benzodiazepine receptor-ionophore complex in cultured cerebral cortical neurons. Brain Res Mol Brain Res. 1992 Nov;16(1-2):29–36. doi: 10.1016/0169-328x(92)90190-m. [DOI] [PubMed] [Google Scholar]
- Meier E., Drejer J., Schousboe A. GABA induces functionally active low-affinity GABA receptors on cultured cerebellar granule cells. J Neurochem. 1984 Dec;43(6):1737–1744. doi: 10.1111/j.1471-4159.1984.tb06102.x. [DOI] [PubMed] [Google Scholar]
- Mhatre M. C., Ticku M. K. Chronic GABA treatment downregulates the GABAA receptor alpha 2 and alpha 3 subunit mRNAS as well as polypeptide expression in primary cultured cerebral cortical neurons. Brain Res Mol Brain Res. 1994 Jul;24(1-4):159–165. doi: 10.1016/0169-328x(94)90128-7. [DOI] [PubMed] [Google Scholar]
- Milner R. J., Sutcliffe J. G. Gene expression in rat brain. Nucleic Acids Res. 1983 Aug 25;11(16):5497–5520. doi: 10.1093/nar/11.16.5497. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Montpied P., Ginns E. I., Martin B. M., Roca D., Farb D. H., Paul S. M. gamma-Aminobutyric acid (GABA) induces a receptor-mediated reduction in GABAA receptor alpha subunit messenger RNAs in embryonic chick neurons in culture. J Biol Chem. 1991 Apr 5;266(10):6011–6014. [PubMed] [Google Scholar]
- Moss S. J., Doherty C. A., Huganir R. L. Identification of the cAMP-dependent protein kinase and protein kinase C phosphorylation sites within the major intracellular domains of the beta 1, gamma 2S, and gamma 2L subunits of the gamma-aminobutyric acid type A receptor. J Biol Chem. 1992 Jul 15;267(20):14470–14476. [PubMed] [Google Scholar]
- Nayeem N., Green T. P., Martin I. L., Barnard E. A. Quaternary structure of the native GABAA receptor determined by electron microscopic image analysis. J Neurochem. 1994 Feb;62(2):815–818. doi: 10.1046/j.1471-4159.1994.62020815.x. [DOI] [PubMed] [Google Scholar]
- Olsen R. W., Tobin A. J. Molecular biology of GABAA receptors. FASEB J. 1990 Mar;4(5):1469–1480. doi: 10.1096/fasebj.4.5.2155149. [DOI] [PubMed] [Google Scholar]
- Pollard S., Duggan M. J., Stephenson F. A. Further evidence for the existence of alpha subunit heterogeneity within discrete gamma-aminobutyric acidA receptor subpopulations. J Biol Chem. 1993 Feb 15;268(5):3753–3757. [PubMed] [Google Scholar]
- Puia G., Vicini S., Seeburg P. H., Costa E. Influence of recombinant gamma-aminobutyric acid-A receptor subunit composition on the action of allosteric modulators of gamma-aminobutyric acid-gated Cl- currents. Mol Pharmacol. 1991 Jun;39(6):691–696. [PubMed] [Google Scholar]
- Quirk K., Gillard N. P., Ragan C. I., Whiting P. J., McKernan R. M. Model of subunit composition of gamma-aminobutyric acid A receptor subtypes expressed in rat cerebellum with respect to their alpha and gamma/delta subunits. J Biol Chem. 1994 Jun 10;269(23):16020–16028. [PubMed] [Google Scholar]
- Roca D. J., Rozenberg I., Farrant M., Farb D. H. Chronic agonist exposure induces down-regulation and allosteric uncoupling of the gamma-aminobutyric acid/benzodiazepine receptor complex. Mol Pharmacol. 1990 Jan;37(1):37–43. [PubMed] [Google Scholar]
- Schousboe A., Redburn D. A. Modulatory actions of gamma aminobutyric acid (GABA) on GABA type A receptor subunit expression and function. J Neurosci Res. 1995 May 1;41(1):1–7. doi: 10.1002/jnr.490410102. [DOI] [PubMed] [Google Scholar]
- Schwartz R. D., Kellar K. J. Nicotinic cholinergic receptor binding sites in the brain: regulation in vivo. Science. 1983 Apr 8;220(4593):214–216. doi: 10.1126/science.6828889. [DOI] [PubMed] [Google Scholar]
- Sieghart W. Structure and pharmacology of gamma-aminobutyric acidA receptor subtypes. Pharmacol Rev. 1995 Jun;47(2):181–234. [PubMed] [Google Scholar]
- Sigel E., Baur R. Activation of protein kinase C differentially modulates neuronal Na+, Ca2+, and gamma-aminobutyrate type A channels. Proc Natl Acad Sci U S A. 1988 Aug;85(16):6192–6196. doi: 10.1073/pnas.85.16.6192. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sigel E., Baur R., Trube G., Möhler H., Malherbe P. The effect of subunit composition of rat brain GABAA receptors on channel function. Neuron. 1990 Nov;5(5):703–711. doi: 10.1016/0896-6273(90)90224-4. [DOI] [PubMed] [Google Scholar]
- Stephenson F. A., Duggan M. J., Pollard S. The gamma 2 subunit is an integral component of the gamma-aminobutyric acidA receptor but the alpha 1 polypeptide is the principal site of the agonist benzodiazepine photoaffinity labeling reaction. J Biol Chem. 1990 Dec 5;265(34):21160–21165. [PubMed] [Google Scholar]
- Sykes C., Prestwich S., Horton R. Chronic administration of the GABA-transaminase inhibitor ethanolamine O-sulphate leads to up-regulation of GABA binding sites. Biochem Pharmacol. 1984 Feb 1;33(3):387–393. doi: 10.1016/0006-2952(84)90230-2. [DOI] [PubMed] [Google Scholar]
- Tehrani M. H., Barnes E. M., Jr GABA down-regulates the GABA/benzodiazepine receptor complex in developing cerebral neurons. Neurosci Lett. 1988 May 3;87(3):288–292. doi: 10.1016/0304-3940(88)90463-6. [DOI] [PubMed] [Google Scholar]
- Thompson C. L., Stephenson F. A. GABAA receptor subtypes expressed in cerebellar granule cells: a developmental study. J Neurochem. 1994 May;62(5):2037–2044. doi: 10.1046/j.1471-4159.1994.62052037.x. [DOI] [PubMed] [Google Scholar]
- Towbin H., Staehelin T., Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. doi: 10.1073/pnas.76.9.4350. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Verdoorn T. A., Draguhn A., Ymer S., Seeburg P. H., Sakmann B. Functional properties of recombinant rat GABAA receptors depend upon subunit composition. Neuron. 1990 Jun;4(6):919–928. doi: 10.1016/0896-6273(90)90145-6. [DOI] [PubMed] [Google Scholar]
- Zezula J., Fuchs K., Sieghart W. Separation of alpha 1, alpha 2 and alpha 3 subunits of the GABAA-benzodiazepine receptor complex by immunoaffinity chromatography. Brain Res. 1991 Nov 1;563(1-2):325–328. doi: 10.1016/0006-8993(91)91556-g. [DOI] [PubMed] [Google Scholar]
- Zheng T., Santi M. R., Bovolin P., Marlier L. N., Grayson D. R. Developmental expression of the alpha 6 GABAA receptor subunit mRNA occurs only after cerebellar granule cell migration. Brain Res Dev Brain Res. 1993 Sep 17;75(1):91–103. doi: 10.1016/0165-3806(93)90068-l. [DOI] [PubMed] [Google Scholar]
- Zimprich F., Zezula J., Sieghart W., Lassmann H. Immunohistochemical localization of the alpha 1, alpha 2 and alpha 3 subunit of the GABAA receptor in the rat brain. Neurosci Lett. 1991 Jun 10;127(1):125–128. doi: 10.1016/0304-3940(91)90910-l. [DOI] [PubMed] [Google Scholar]