First person – Fanny Jaudon and Martina Albini

Fanny Jaudon

How would you explain the main findings of your paper in lay terms?

F.J.: Neurotrophins such as NGF or BDNF are growth factors that regulate the survival, development and function of the brain. While their effects on neurons have been extensively studied, it is becoming increasingly clear that they also act on astrocytes, but their role in this cell type remains poorly characterized. In this work, we investigated how astrocytes respond to BDNF stimulation and analyzed the role of the protein Kidins220 in this response. Indeed, Kidins220 is a scaffold protein that mediates neurotrophin signaling in neurons and is also expressed in astrocytes, where it regulates calcium signaling and neuron–astrocyte communication. We showed that the astrocyte responsiveness to BDNF depends on the developmental stage of the cultures and on the presence of Kidins220.

M.A.: Astrocytes are no longer purely viewed as support cells for neurons, and it is now clear that they play active roles modulating neuronal activity. In this paper, we compared the signaling competence of embryonic and postnatal primary cortical astrocytes and identified a developmental stage- and Kidins220-dependent switch in astrocyte responsiveness to BDNF. Our data contribute to the understanding of the complex role played by astrocytes within the central nervous system, and identify Kidins220 as a novel actor in the increasing number of pathologies characterized by astrocytic dysfunctions.

Were there any specific challenges associated with this project? If so, how did you overcome them?

F.J.: The experiments on BDNF signaling in astrocytes were one of the first things I started when I joined Fabrizia Cesca's group, but it took a long time before the completion of the project, and I had moved to another group by then. Fortunately, Martina joined the lab soon after and she took over the experiments. While in another group, I was still working in the same institute for a while, so I could easily follow the advancement of the project and help with the experiments in my free time. I eventually moved to Trieste but managed to keep being involved via Skype meetings.

M.A.: My supervisor was working in a different city and although we had regular meetings, it was sometimes difficult to plan and troubleshoot my experiments on my own. Also, as a PhD student who has a limited amount of time to conduct experiments, the coronavirus pandemic was a big challenge. This has, however, allowed me to become more independent and develop skills to bring the project forward.

Martina Albini

When doing the research, did you have a particular result or ‘eureka’ moment that has stuck with you?

F.J.: When we started the project, we worked only on embryonic astrocyte cultures. BDNF was known to evoke calcium transients in astrocytes, so we wanted to see whether Kidins220 was involved in this process. Despite all our efforts, we did not manage to elicit a robust response in our embryonic wild-type cultures and I was convinced that this would never work. We then started to work on postnatal cultures and at the end of one day of recording we decided to give the BDNF stimulation another shot on the last coverslip we had. Surprisingly, we observed for the first time a strong BDNF-evoked calcium transient! We then repeated this the following days and it became clear that the developmental stage of the culture was a determinant in the BDNF response.

Why did you choose Journal of Cell Science for your paper?

M.A.: We were looking for a journal with a good reputation, publishing high quality studies in the field of cell biology and neuroscience. Journal of Cell Science was the perfect fit!

What's next for you? (If you are planning on leaving academia, please tell us why!)

F.J.: I will be working at the University of Trieste for the next two years. Then, I plan to go back to France and apply for a permanent researcher position at the CNRS and eventually start my own group.

M.A.: I will be finishing my PhD in the next few months; I then plan to apply for a postdoc position and continue my career in academia.