Year 1

The progress in our research regarding the role of human astrocytes in Rett syndrome (RTT) showed us that RTT-derived astrocyte display several phenotypes that illustrate its differences compared to healthy control astrocytes (WT). RTT astrocytes are unable to propagate calcium wave when mechanically stimulated . In addition to that, when placed in medium that contains glutamate, the natural uptake and buffering of this compound is impaired in RTT-derived astrocytes. Furthermore, when WT neurons are placed on top of RTT astrocytes, there is a clear the negative effect of these cells in neuronal homeostasis. Remarkably, WT astrocytes are able to rescue RTT neuronal phenotypes when in direct contact, illustrating the important role that astrocytes have in maintaining neuronal viability and maturation. Several mis-regulation in gene expression pathways indicated those phenotypes, both in calcium and glutamate dependent genes. Strikingly, further genetic analysis led us to identify several mis-regulations in pro-inflammatory cytokines. Multiplex ELISA platforms also pointed towards a difference in cytokine secretion between WT and RTT syndrome astrocytes, being the RTT cells illustrative of a pro-inflammatory scenario. We have define one of these secreted cytokines as our primary read out for the HT-screening. We are now facing a transportation issue with very sensitive cells, but have an innovative plan to make it to work and also get some quick results that may have clinical relevance.