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Chronic intermittent hypoxia increases encoding pigment epithelium-derived factor gene expression, although not that of the protein itself, in the temporal cortex of rats, / Hipóxia intermitente crônica aumenta a expressão gênica, mas não proteica, de pigment epithelium-derived factor no córtex temporal de ratos
Julian, Guilherme Silva; Oliveira, Renato Watanabe de; Favaro, Vanessa Manchim; Oliveira, Maria Gabriela Menezes de; Perry, Juliana Cini; Tufik, Sergio; Chagas, Jair Ribeiro.
  • Julian, Guilherme Silva; Federal University of São Paulo. Paulista School of Medicine. Department of Psychobiology. São Paulo. BR
  • Oliveira, Renato Watanabe de; Federal University of São Paulo. Paulista School of Medicine. Department of Psychobiology. São Paulo. BR
  • Favaro, Vanessa Manchim; Federal University of São Paulo. Paulista School of Medicine. Department of Psychobiology. São Paulo. BR
  • Oliveira, Maria Gabriela Menezes de; Federal University of São Paulo. Paulista School of Medicine. Department of Psychobiology. São Paulo. BR
  • Perry, Juliana Cini; Federal University of São Paulo. Paulista School of Medicine. Department of Psychobiology. São Paulo. BR
  • Tufik, Sergio; Federal University of São Paulo. Paulista School of Medicine. Department of Psychobiology. São Paulo. BR
  • Chagas, Jair Ribeiro; Federal University of São Paulo. Paulista School of Medicine. Department of Psychobiology. São Paulo. BR
J. bras. pneumol ; 41(1): 39-47, Jan-Feb/2015. tab, graf
Article in English | LILACS | ID: lil-741566
ABSTRACT

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. .
RESUMO

Objetivo:

A síndrome da apneia obstrutiva do sono caracteriza-se principalmente por episódios de hipóxia intermitente (HI) durante o sono e associa-se a diversas complicações. A exposição à HI é o mais usado modelo animal de apneia do sono, e protocolos de curta duração causam diversos prejuízos cognitivos e neuronais. Pigment epithelium-derived factor (PEDF, fator derivado do epitélio pigmentado) é um fator neurotrófico, neuroprotetor e antiangiogênico sensível à hipóxia celular. Nosso estudo analisou o desempenho em tarefas cognitivas e de aprendizagem, bem como a expressão do gene PEDF e da proteína PEDF em estruturas cerebrais específicas em ratos expostos a HI de longa duração.

Métodos:

Ratos Wistar foram expostos a HI (21-5% de oxigênio) durante 6 semanas - o grupo HI crônica (HIC) - ou a normóxia durante 6 semanas - o grupo controle. Após a exposição à HIC, um grupo de ratos foi exposto a normóxia durante 2 semanas (o grupo HIC+N). Todos os animais foram submetidos ao labirinto aquático de Morris para avaliação de memória e aprendizado; avaliou-se também a expressão do gene PEDF e da proteína PEDF no hipocampo e nos córtices frontal e temporal.

Resultados:

Os grupos HIC e HIC+N apresentaram um aumento de expressão do gene PEDF no córtex temporal, porém sem aumento dos níveis proteicos. A expressão do gene PEDF e da proteína PEDF manteve-se inalterada nas demais estruturas. A exposição de longa duração à HI não afetou a função cognitiva.

Conclusões:

A exposição de longa duração à HI aumenta seletivamente a expressão do gene PEDF ao nível transcricional, embora apenas no córtex temporal. Esse aumento é provavelmente um mecanismo de proteção contra a HI. .
Subject(s)


Full text: Available Index: LILACS (Americas) Main subject: Blood Glucose / Cardiovascular Diseases / Weight Loss / Diet, Fat-Restricted / Diet, Carbohydrate-Restricted / Weight Reduction Programs Type of study: Controlled clinical trial / Etiology study / Observational study / Prognostic study / Risk factors Limits: Adult / Aged / Female / Humans / Male Language: English Journal: J. bras. pneumol Journal subject: Pulmonary Disease (Specialty) Year: 2015 Type: Article / Project document Affiliation country: Brazil Institution/Affiliation country: Federal University of São Paulo/BR

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Full text: Available Index: LILACS (Americas) Main subject: Blood Glucose / Cardiovascular Diseases / Weight Loss / Diet, Fat-Restricted / Diet, Carbohydrate-Restricted / Weight Reduction Programs Type of study: Controlled clinical trial / Etiology study / Observational study / Prognostic study / Risk factors Limits: Adult / Aged / Female / Humans / Male Language: English Journal: J. bras. pneumol Journal subject: Pulmonary Disease (Specialty) Year: 2015 Type: Article / Project document Affiliation country: Brazil Institution/Affiliation country: Federal University of São Paulo/BR