Chronic intermittent hypoxia increases encoding pigment epithelium-derived factor gene expression, although not that of the protein itself, in the temporal cortex of rats*,**
نویسندگان
چکیده
OBJECTIVE Obstructive sleep apnea syndrome is mainly characterized by intermittent hypoxia (IH) during sleep, being associated with several complications. Exposure to IH is the most widely used animal model of sleep apnea, short-term IH 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 PEDF gene expression and PEDF protein expression in specific brain structures, in rats exposed to long-term IH. METHODS Male Wistar rats were exposed to IH (oxygen concentrations of 21-5%) for 6 weeks-the chronic IH (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. PEDF gene expression and PEDF protein expression remained unaltered in the frontal cortex and hippocampus. Long-term exposure to IH did not affect cognitive function. CONCLUSIONS Long-term exposure to IH selectively increases PEDF gene expression at the transcriptional level, although only in the temporal cortex. This increase is probably a protective mechanism against IH-induced injury.
منابع مشابه
Pigment epithelium-derived factor: clinical significance in estrogen-dependent tissues and its potential in cancer therapy
Pigment epithelium-derived factor (PEDF) is a glycoprotein that belongs to the family of non-inhibitory serpins. The broad spectrum of PEDF biological activity is evident when considering its effects in promoting cell survival and proliferation, as well as its antiangiogenic, antitumor, and anti-metastatic properties. Although the structural domains of the PEDF gene that mediate such diverse ef...
متن کاملComparison of Effects of High-Fat, High-Protein and Low-Calorie Diets on Klotho Gene Expression and TGF-β Level in Serum and Liver of Old Male Wistar Rats
Background and Objectives: Different diets have important roles in human health and aging. In the current study, we aimed to characterize the Klotho, an anti-aging protein, gene expression and protein level in the serum and assess the protein levels of Transforming growth factor-β and Platelet-derived growth factor in old rats which treated with different diets (high-fat, high-protein, low calo...
متن کاملP 128: Sleep Disturbance and Epilepsy: An Inflammatory Pathway
Sleep plays a vital role in regulating physiological mechanisms in the human body. Nowadays, by the change of lifestyle and as a consequence of longer work hours and increased accessibility to media, sleep disturbance becomes a common problem in modern society. Many studies demonstrated that sleep disturbance triggers a systemic low-grade inflammation by increasing the level of several cytokine...
متن کاملP 55: Sleep Disturbance and Epilepsy: an Inflammatory Pathway
Sleep plays a vital role in regulating physiological mechanisms in the human body. Nowadays, by the change of lifestyle and as a consequence of longer work hours and increased accessibility to media, sleep disturbance becomes a common problem in modern society. Many studies demonstrated that sleep disturbance triggers a systemic low-grade inflammation by increasing the level of several cytokine...
متن کاملAction of brain-derived neurotrophic factor on function and morphology of visual cortical neurons
Brain-derived neurotrophic factor (BDNF) is known to play a role in experience-dependent plasticity of the developing visual cortex. For example, BDNF acutely enhances long-term potentiation and blocks long-term depression in the visual cortex of young rats. Such acute actions of BDNF suggested to be mediated mainly through presynaptic mechanisms. A chronic application of BDNF to the visual cor...
متن کامل