Abstract
It is reported that antidepressant (AD) treatment can upregulate cAMP cascadeactivity in depressed individuals. Evidence implicates lipid rafts (LRs), regions of
the membrane which localise intracellular signalling machinery, stating that by
modifying LRs, ADs facilitate Gαs signalling to adenylyl cyclase (AC). However, AD-LR interactions remain elusive and valid LR-markers are lacking. I have generated a potential non-invasive marker for rafts, AKAP5-Td-Tomato, which labelled primary astrocyte and HEK293 membranes but caused abnormal morphology, likely by protein kinase A (PKA)-mediated signalling; further optimisation of the marker is required. Then, an Epac-based FRET sensor for cAMP was used to determine if AD pre-incubation increased AC activity. Contrary to prior research, there was no overall effect of AD or incubation-time on cAMP response in astrocytes. However, 24h pre-incubation with imipramine potentiated cAMP response of astrocytes to adenosine. Lastly we couldn’t confirm the reported ability of ketamine to facilitate Gαs signalling. Since previous evidence was obtained in C6 glioma cells, it is likely that this is not reproducible in non-malignant primary dissociated astrocytes. We suggest that a broader range of ADs and agonists must be tested, as well as more functional markers such as PKA activity, before a comprehensive conclusion can be reached.
| Date of Award | 27 Sept 2022 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Sergey Kasparov (Supervisor) & Anja G Teschemacher (Supervisor) |