Project 03

Expression of RNA based TrkB-aptamers for the treatment of age-related macular degeneration.

Host institution: Eberhard Karls University of Tübingen
PhD: Yes
Duration: 36

Degenerative processes of the retina, such as those occurring in AMD usually result in cell death of neuronal cells.


Degenerative processes of the retina, such as those occurring in AMD usually result in cell death of neuronal cells, especially photoreceptors and ultimately leading to irreversible blindness. Growth factor-based therapy is a widely studied approach for slowing down or arrest neuronal degeneration. BDNF is a promising neurotrophic growth factor that exerts its effects via activation of the TrkB signalling cascade. However, direct stimulation with BDNF bears several side effects.

By using an existing RNA-aptamer that specifically binds to the TrkB receptor, we are able to precisely mimic the neuroprotective effects of BDNF and develop a new therapeutic option for neuronal diseases.

Aptameric therapies offer the benefit, that their binding to receptors and thereby activation of signalling pathways can be triggered with an unmet sensitivity compared to antibodies or pristine small molecules. In result, the activation of intrinsic neuroprotective pathways with an aptamer promotes survival of essential neurons in the retina with very limited risk of overstimulation or side effects. In ex vivo experiments, we demonstrated the excellent and improved neuroprotective effect of the unbound RNA aptamer on retinal organ cultures (Hurst et al. preliminary work). For the permanent cellular expression needed in chronic diseases, we will use the recently developed mammalian autocatalytic circular RNA expression vector (Tornado system), which allows the expression and functional activity of RNA aptamers in sufficient amounts without the need for additional co-factors (Litke et al. 2019). After ex vivo establishment in retinal organ cultures, the approaches will then be evaluated in in vivo models of AMD.

The aim of this project is to demonstrate that TrkB signalling activation via highly specific aptamers directly expressed have a therapeutic effect for AMD.


Expected results

  1. Establish cellular expression of TrkB-aptamer in vitro, ex and in vivo
  2. Analyze expression pattern after successful expression of TrkB-aptamer
  3. Proof of concept, that aptamer-based stimulation of TrkB signaling pathways causes neuroprotective effects in chronic (AMD) neurodegenerative ocular models

Planned secondments

  1. B6, supervisor: Jan Wijnholds
    Purpose: Training in production and usage of rAAV
  2. AP7, supervisor: Beatriz Llamusí
    Purpose: business training
  3. B7, supervisor: Aileen Murphy
    Purpose: business and economic training