Chronic intermittent hypoxia increases encoding pigment epithelium-derived factor gene expression, although not that of the protein itself, in the temporal cortex of rats

Author(s)

Julian, Guilherme Silva ^[1] ; de Oliveira, Renato Watanabe ^[1] ; Favaro, Vanessa Manchim ^[1] ; Menezes de Oliveira, Maria Gabriela ^[1] ; Perry, Juliana Cini ^[1] ; Tufik, Sergio ^[1] ; Chagas, Jair Ribeiro ^[1]

Affiliation

^[1] Univ Fed Sao Paulo, Dept Biosci, Santos - Brazil

• Document type: Journal article
• Source: Jornal Brasileiro de Pneumologia; v. 41, n. 1, p. 39-47, JAN-FEB 2015.
• Web of Science Citations: 2

Abstract

Objective: Obstructive sleep apnea syndrome is mainly characterized by intermittent hypoxia (1H) during sleep, being associated with several complications. Exposure to IN is the most widely used animal model of sleep apnea, short-term 1H exposure resulting in cognitive and neuronal impairment. Pigment epithelium-derived factor (PEDF) is a hypoxia-sensitive factor acting as a neurotrophic, neuroprotective, and antiangiogenic agent. Our study analyzed performance on learning and cognitive tasks, as well as PEDFgene expression and PEDF protein expression in specific brain structures, in rats exposed to long-term IN. Methods: Male Wistar rats were exposed to 111 (oxygen concentrations of 21-5%) for 6 weeks the chronic 1H (CIH) group or normoxia for 6 weeks the control group. After CIH exposure, a group of rats were allowed to recover under normoxic conditions for 2 weeks (the CIH+N group). All rats underwent the Morris water maze test for learning and memory, PEDF gene expression and PEDF protein expression in the hippocampus, frontal cortex, and temporal cortex being subsequently assessed. Results: The CIH and CIH+N groups showed increased PEDF gene expression in the temporal cortex, PEDF protein expression remaining unaltered. PEDFgene expression and PEDF protein expression remained unaltered in the frontal cortex and hippocampus. Long-term exposure to 1H did not affect cognitive function. Conclusions: Long-term exposure to 1H selectively increases PEDFgene expression at the transcriptional level, although only in the temporal cortex. This increase is probably a protective mechanism against 1H-induced injury. (AU)

• FAPESP's process: 11/16011-6 - Evaluation of the effect of hypoxia on the expression and activity of neprilysin (EC 3.4.24.11), a protease involved in Alzheimer's Disease
• Grantee: Renato Watanabe de Oliveira
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 11/03791-3 - Analysis of the chronic treatment effects of Ayahuasca on memory and anxiety in rats
• Grantee: Vanessa Manchim Favaro
• Support Opportunities: Scholarships in Brazil - Master