d'mel-affy-rat-168311

Neurological diseases disrupt the quality of the lives of patients and often lead to their death prematurely. A common feature of most neurological diseases is the degeneration of neurons, which results from an inappropriate activation of apoptosis. Drugs that inhibit neuronal apoptosis could thus be candidates for therapeutic intervention in neurodegenerative disorders. We have identified (and recently reported) a chemical called GW5074 that inhibits apoptosis in a variety of cell culture paradigms of neuronal apoptosis. Additionally, we have found that GW5074 reduces neurodegeneration and improves behavioral outcome in a mouse model of Huntington's disease. Although GW5074 is a c-Raf inhibitor, we know very little about the molecular mechanisms underlying its neuroprotective action. Identifying genes that are regulated by GW5074 in neurons will shed insight into this issue. We believe that neuroprotection by GW5074 involves the regulation of several genes. Some of these genes are likely to be induced whereas the expression of other genes might be inhibited. The specific aim is to identify genes that are differentially expressed in neurons treated with GW5074. We believe that neuroprotection by GW5074 involves the regulation of several genes. Some of these genes are likely to be induced whereas the expression of other genes might be inhibited. Cultures of cerebellar granule neurons undergo apoptosis when switched from medium containing levated levels of potassium (high K+ or HK) to medium containing low potassium (LK). Although cell death begins at about 18 h, we have found that the by 6 h after LK treatment these neurons are irreversibly committed to cell death. We will treat cerebellar granule neuron cultures with LK medium (which induces them to undergo apoptosis) or with GW5074 (1 uM). We will extract RNA at two time-points after treatment: 3 h and 6 h. Analysis at the two different time-points will show us whether changes in expression of specific genes is transient or sustained or whether the changes occurs early or relatively late in the process. Neuronal cultures will be prepared from 1 week old Wistar rats. The cultures will be maintained in culture for 1 week before treatment. Following treatment the cells will be lysed and total RNA isolated. The RNA will be stored at -80oC and shipped to the microarray facility for analysis. The experiment will be done in triplicate. Thus, for each time-point (3 or 6h treatment) we will be hope to provide 3 sets of samples (each set coming from a different culture preparation and containing lysates from cells treated with LK or GW5074). Having samples from 3 independent cultures will mitigate any expression differences resulting from subtle variations in culture quality or in the preparation or quality of RNA. Keywords: dose response as above