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. 2001 Aug 1;357(Pt 3):819–826. doi: 10.1042/0264-6021:3570819

Possible mechanisms involved in the down-regulation of translation during transient global ischaemia in the rat brain.

C Martín de la Vega 1, J Burda 1, M Nemethova 1, C Quevedo 1, A Alcázar 1, M E Martín 1, V Danielisova 1, J L Fando 1, M Salinas 1
PMCID: PMC1222012  PMID: 11463353

Abstract

The striking correlation between neuronal vulnerability and down-regulation of translation suggests that this cellular process plays a critical part in the cascade of pathogenetic events leading to ischaemic cell death. There is compelling evidence supporting the idea that inhibition of translation is exerted at the polypeptide chain initiation step, and the present study explores the possible mechanism/s implicated. Incomplete forebrain ischaemia (30 min) was induced in rats by using the four-vessel occlusion model. Eukaryotic initiation factor (eIF)2, eIF4E and eIF4E-binding protein (4E-BP1) phosphorylation levels, eIF4F complex formation, as well as eIF2B and ribosomal protein S6 kinase (p70(S6K)) activities, were determined in different subcellular fractions from the cortex and the hippocampus [the CA1-subfield and the remaining hippocampus (RH)], at several post-ischaemic times. Increased phosphorylation of the alpha subunit of eIF2 (eIF2 alpha) and eIF2B inhibition paralleled the inhibition of translation in the hippocampus, but they normalized to control values, including the CA1-subfield, after 4--6 h of reperfusion. eIF4E and 4E-BP1 were significantly dephosphorylated during ischaemia and total eIF4E levels decreased during reperfusion both in the cortex and hippocampus, with values normalizing after 4 h of reperfusion only in the cortex. Conversely, p70(S6K) activity, which was inhibited in both regions during ischaemia, recovered to control values earlier in the hippocampus than in the cortex. eIF4F complex formation diminished both in the cortex and the hippocampus during ischaemia and reperfusion, and it was lower in the CA1-subfield than in the RH, roughly paralleling the observed decrease in eIF4E and eIF4G levels. Our findings are consistent with a potential role for eIF4E, 4E-BP1 and eIF4G in the down-regulation of translation during ischaemia. eIF2 alpha, eIF2B, eIF4G and p70(S6K) are positively implicated in the translational inhibition induced at early reperfusion, whereas eIF4F complex formation is likely to contribute to the persistent inhibition of translation observed at longer reperfusion times.

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Selected References

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  1. Alcázar A., Martín de la Vega C., Bazán E., Fando J. L., Salinas M. Calcium mobilization by ryanodine promotes the phosphorylation of initiation factor 2alpha subunit and inhibits protein synthesis in cultured neurons. J Neurochem. 1997 Oct;69(4):1703–1708. doi: 10.1046/j.1471-4159.1997.69041703.x. [DOI] [PubMed] [Google Scholar]
  2. Alcázar A., Martín M. E., Soria E., Rodríguez S., Fando J. L., Salinas M. Purification and characterization of guanine nucleotide-exchange factor, eIF-2B, and p37 calmodulin-binding protein from calf brain. J Neurochem. 1995 Aug;65(2):754–761. doi: 10.1046/j.1471-4159.1995.65020754.x. [DOI] [PubMed] [Google Scholar]
  3. Bergstedt K., Hu B. R., Wieloch T. Initiation of protein synthesis and heat-shock protein-72 expression in the rat brain following severe insulin-induced hypoglycemia. Acta Neuropathol. 1993;86(2):145–153. doi: 10.1007/BF00334881. [DOI] [PubMed] [Google Scholar]
  4. Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
  5. Burda J., Martín M. E., García A., Alcázar A., Fando J. L., Salinas M. Phosphorylation of the alpha subunit of initiation factor 2 correlates with the inhibition of translation following transient cerebral ischaemia in the rat. Biochem J. 1994 Sep 1;302(Pt 2):335–338. doi: 10.1042/bj3020335. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Burda J., Martín M. E., Gottlieb M., Chavko M., Marsala J., Alcázar A., Pavón M., Fando J. L., Salinas M. The intraischemic and early reperfusion changes of protein synthesis in the rat brain. eIF-2 alpha kinase activity and role of initiation factors eIF-2 alpha and eIF-4E. J Cereb Blood Flow Metab. 1998 Jan;18(1):59–66. doi: 10.1097/00004647-199801000-00006. [DOI] [PubMed] [Google Scholar]
  7. Cooper H. K., Zalewska T., Kawakami S., Hossmann K. A., Kleihues P. The effect of ischaemia and recirculation on protein synthesis in the rat brain. J Neurochem. 1977 May;28(5):929–934. doi: 10.1111/j.1471-4159.1977.tb10652.x. [DOI] [PubMed] [Google Scholar]
  8. DeGracia D. J., Neumar R. W., White B. C., Krause G. S. Global brain ischemia and reperfusion: modifications in eukaryotic initiation factors associated with inhibition of translation initiation. J Neurochem. 1996 Nov;67(5):2005–2012. doi: 10.1046/j.1471-4159.1996.67052005.x. [DOI] [PubMed] [Google Scholar]
  9. DeGracia D. J., Sullivan J. M., Neumar R. W., Alousi S. S., Hikade K. R., Pittman J. E., White B. C., Rafols J. A., Krause G. S. Effect of brain ischemia and reperfusion on the localization of phosphorylated eukaryotic initiation factor 2 alpha. J Cereb Blood Flow Metab. 1997 Dec;17(12):1291–1302. doi: 10.1097/00004647-199712000-00004. [DOI] [PubMed] [Google Scholar]
  10. Dienel G. A., Pulsinelli W. A., Duffy T. E. Regional protein synthesis in rat brain following acute hemispheric ischemia. J Neurochem. 1980 Nov;35(5):1216–1226. doi: 10.1111/j.1471-4159.1980.tb07878.x. [DOI] [PubMed] [Google Scholar]
  11. Gingras A. C., Raught B., Sonenberg N. eIF4 initiation factors: effectors of mRNA recruitment to ribosomes and regulators of translation. Annu Rev Biochem. 1999;68:913–963. doi: 10.1146/annurev.biochem.68.1.913. [DOI] [PubMed] [Google Scholar]
  12. Goldstein E. N., Owen C. R., White B. C., Rafols J. A. Ultrastructural localization of phosphorylated eIF2alpha [eIF2alpha(P)] in rat dorsal hippocampus during reperfusion. Acta Neuropathol. 1999 Nov;98(5):493–505. doi: 10.1007/s004010051115. [DOI] [PubMed] [Google Scholar]
  13. Hashimoto K., Kikuchi H., Ishikawa M., Kobayashi S. Changes in cerebral energy metabolism and calcium levels in relation to delayed neuronal death after ischemia. Neurosci Lett. 1992 Mar 30;137(2):165–168. doi: 10.1016/0304-3940(92)90395-n. [DOI] [PubMed] [Google Scholar]
  14. Hossmann K. A. Disturbances of cerebral protein synthesis and ischemic cell death. Prog Brain Res. 1993;96:161–177. doi: 10.1016/s0079-6123(08)63265-3. [DOI] [PubMed] [Google Scholar]
  15. Hu B. R., Wieloch T. Stress-induced inhibition of protein synthesis initiation: modulation of initiation factor 2 and guanine nucleotide exchange factor activities following transient cerebral ischemia in the rat. J Neurosci. 1993 May;13(5):1830–1838. doi: 10.1523/JNEUROSCI.13-05-01830.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Kim Y. M., Son K., Hong S. J., Green A., Chen J. J., Tzeng E., Hierholzer C., Billiar T. R. Inhibition of protein synthesis by nitric oxide correlates with cytostatic activity: nitric oxide induces phosphorylation of initiation factor eIF-2 alpha. Mol Med. 1998 Mar;4(3):179–190. [PMC free article] [PubMed] [Google Scholar]
  17. Kozak M. An analysis of vertebrate mRNA sequences: intimations of translational control. J Cell Biol. 1991 Nov;115(4):887–903. doi: 10.1083/jcb.115.4.887. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Lawrence J. C., Jr, Abraham R. T. PHAS/4E-BPs as regulators of mRNA translation and cell proliferation. Trends Biochem Sci. 1997 Sep;22(9):345–349. doi: 10.1016/s0968-0004(97)01101-8. [DOI] [PubMed] [Google Scholar]
  19. Lipton P. Ischemic cell death in brain neurons. Physiol Rev. 1999 Oct;79(4):1431–1568. doi: 10.1152/physrev.1999.79.4.1431. [DOI] [PubMed] [Google Scholar]
  20. Martin M. E., Garcia A. M., Blanco L., Herrera E., Salinas M. Effect of streptozotocin diabetes on polysomal aggregation and protein synthesis rate in the liver of pregnant rats and their offspring. Biosci Rep. 1995 Feb;15(1):15–20. doi: 10.1007/BF01200211. [DOI] [PubMed] [Google Scholar]
  21. Martín de la Vega C., Burda J., Salinas M. Ischemia-induced inhibition of the initiation factor 2alpha phosphatase activity in the rat brain. Neuroreport. 2001 Apr 17;12(5):1021–1025. doi: 10.1097/00001756-200104170-00031. [DOI] [PubMed] [Google Scholar]
  22. Martín M. E., Muñoz F. M., Salinas M., Fando J. L. Ischaemia induces changes in the association of the binding protein 4E-BP1 and eukaryotic initiation factor (eIF) 4G to eIF4E in differentiated PC12 cells. Biochem J. 2000 Oct 15;351(Pt 2):327–334. [PMC free article] [PubMed] [Google Scholar]
  23. Maruno M., Yanagihara T. Progressive loss of messenger RNA and delayed neuronal death following transient cerebral ischemia in gerbils. Neurosci Lett. 1990 Jul 31;115(2-3):155–160. doi: 10.1016/0304-3940(90)90447-h. [DOI] [PubMed] [Google Scholar]
  24. Muñoz F., Martín M. E., Manso-Tomico J., Berlanga J., Salinas M., Fando J. L. Ischemia-induced phosphorylation of initiation factor 2 in differentiated PC12 cells: role for initiation factor 2 phosphatase. J Neurochem. 2000 Dec;75(6):2335–2345. doi: 10.1046/j.1471-4159.2000.0752335.x. [DOI] [PubMed] [Google Scholar]
  25. Neumar R. W., DeGracia D. J., Konkoly L. L., Khoury J. I., White B. C., Krause G. S. Calpain mediates eukaryotic initiation factor 4G degradation during global brain ischemia. J Cereb Blood Flow Metab. 1998 Aug;18(8):876–881. doi: 10.1097/00004647-199808000-00007. [DOI] [PubMed] [Google Scholar]
  26. Pulsinelli W. A., Brierley J. B. A new model of bilateral hemispheric ischemia in the unanesthetized rat. Stroke. 1979 May-Jun;10(3):267–272. doi: 10.1161/01.str.10.3.267. [DOI] [PubMed] [Google Scholar]
  27. Schmidt-Kastner R., Paschen W., Ophoff B. G., Hossmann K. A. A modified four-vessel occlusion model for inducing incomplete forebrain ischemia in rats. Stroke. 1989 Jul;20(7):938–946. doi: 10.1161/01.str.20.7.938. [DOI] [PubMed] [Google Scholar]
  28. Thilmann R., Xie Y., Kleihues P., Kiessling M. Persistent inhibition of protein synthesis precedes delayed neuronal death in postischemic gerbil hippocampus. Acta Neuropathol. 1986;71(1-2):88–93. doi: 10.1007/BF00687967. [DOI] [PubMed] [Google Scholar]

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