Differential expression of hippocampal connexins after acute hypoxia in the developing brain

Zeinieh, Michele P.; Talhouk, Rabih S.; El-Sabban, Marwan E.; Mikati, Mohamad A.

doi:10.1016/j.braindev.2009.11.003

« Previous Next »Brain and Development
Volume 32, Issue 10 , Pages 810-817, November 2010

Differential expression of hippocampal connexins after acute hypoxia in the developing brain

Michele P. Zeinieh
- Department of Biology, American University of Beirut, Beirut, Lebanon
Rabih S. Talhouk
- Department of Biology, American University of Beirut, Beirut, Lebanon
Marwan E. El-Sabban
- Department of Human Morphology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Corresponding authors. Address: Department of Pediatrics and Adolescent Medicine, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon. Tel.: +961 1 350000x5500; fax: +961 1 351706. (M.A. Mikati);Department of Human Morphology, Faculty of Medicine, American Unversity of Beirut, P.O.Box 11-0236, Beirut, Lebanon. Tel.: +961 1 350000x4765; fax: +961 1 744464. (M.E. El-Sabban).
Mohamad A. Mikati
- Adult and Pediatric Epilepsy Program, Department of Pediatrics and Adolescent Medicine, American University of Beirut, Beirut, Lebanon
- Department of Biochemistry, American University of Beirut, Beirut, Lebanon
- Corresponding authors. Address: Department of Pediatrics and Adolescent Medicine, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon. Tel.: +961 1 350000x5500; fax: +961 1 351706. (M.A. Mikati);Department of Human Morphology, Faculty of Medicine, American Unversity of Beirut, P.O.Box 11-0236, Beirut, Lebanon. Tel.: +961 1 350000x4765; fax: +961 1 744464. (M.E. El-Sabban).
- Present address: Division of Child Neurology and Department Of Neurobiology, Duke University, Durham, North Carolina.

Received 4 May 2009; received in revised form 30 September 2009; accepted 5 November 2009. published online 25 December 2009.

Abstract

Acute hypoxia at postnatal day (P) 10 is an accepted model of human neonatal hypoxia which results, among other consequences, in increased hippocampal excitability. Hypoxic–ischemic injury, which mimics stroke, has been shown to result in changes in connexins (Cxs), however, changes in Cxs have not been studied in the P10 hypoxia model. The aim of this study was to investigate changes in the hippocampal expression of three different connexins at consecutive developmental stages after acute hypoxia at P10 (10min and 30min after reoxygenation, P11, P14, P17, P29, and P45) as compared to sham manipulated pups. After acute hypoxia at P10, Cx30 protein levels were increased at 30min after reoxygenation, at P11 and at P14, and then returned to control levels. Cx36 protein levels transiently decreased at P11 after acute hypoxia then returned to control levels. Cx43 protein levels did not change at any of the time points. Although changes in mRNA expression were observed during development for Cx30 only, acute hypoxia did not result in changes in mRNA expression of all these Cxs when compared to age matched controls suggesting that acute hypoxia induced posttranslational changes in protein expression.