Transcription profiling of rats subjected to hypoxic preconditioning or sham conditioning at several time points from 0 to 24 hrs after preconditioning

ABSTRACT: Hypoxic-ischemic (HI) injury in the developing brain is a common cause of disability in children, and there are no effective treatments at this time. Exposure to sublethal hypoxic conditions (hypoxic preconditioning) 24 hours prior to hypoxic-ischemic insult is protective in the developing rat model. We have observed protective effects on brain histopathology and on long-term sensory-motor behavioral tasks. Changes in gene expression are thought to underlie this protective effect. By comparing gene expression in rats subjected to hypoxic preconditioning or sham conditioning at several time points from 0 to 24 hrs after preconditioning, we should gain insight into the mechanisms underlying these neuroprotective effects and may identify targets for therapeutic intervention. The aim of this study is to determine the effect of hypoxic preconditioning on global gene expression, and, in littermates, to examine the effect of hypoxic preconditioning 24 h prior to hypoxic-ischemic insult on brain histopathology. We hypothesize that changes in gene expression underlie the protective effect of hypoxic preconditioning against subsequent hypoxic-ischemic insult. Gene expression will be examined in two groups, 1) preconditioned and 2) sham controls, at 4 time points. On postnatal day 6, preconditioned animals are exposed to normothermic hypoxia for 3 hrs (8.0% oxygen, 36 degrees C), and sham animals are simultaneouosly exposed to normoxia at 36 degrees C. Animals are then returned to their dams until euthanized at 4 time points (0h, 2h, 8h, and 24h later). Five brains/group/timepoint will be used, with an equal number of males and females in each group. Brains are removed and dissected on ice. Cerebral cortex is dissected from both hemispheres and rapidly frozen on dry ice. Total RNA is isolated using the QIAGEN RNeasy Protect Maxi Kit. Littermates of these animals will be exposed to hypoxic preconditioning or sham preconditioning and subjected to hypoxic-ischemic injury 24 h later. These animals are euthanized at postnatal day 14 for histopathologic evaluation of injury.

ORGANISM(S): Rattus norvegicus

SUBMITTER: Elizabeth Salomon 

PROVIDER: E-GEOD-4753 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress