apr
Christina-Anastasia Stamouli- Institutionen för experimentell medicinsk vetenskap
Title: Generating interneurons for cell replacement and disease modelling
Main supervisor: Daniella Rylander Ottosson
Reviewers: Marco Ledri and Christopher Douse
Abstract
Background
Cortical GABAergic interneurons are inhibitory neurons that are essential for brain neuronal circuitry and plasticity. Loss or damage to these neurons are implicated in many neurological disorders e.g. Schizophrenia, autism-spectrum disorders, or epilepsy. Cell restoration strategies hold great promise for treatment of these diseases, such as transplantation of interneuron precursors. An alternative attractive approach for cell repair to the brain is through direct reprogramming. With this technique, a non-neuronal cell such as glia cell, can be turned into a neuron by overexpressing specific neuronal transcription factors. Our team has demonstrated that mouse glia cells can be reprogrammed into specific interneurons in the living mouse brain. We have further translated this protocol into the human system reprogramming stem cell derived human glia into interneurons in vitro. My thesis
In addition to cell repair purposes direct reprogramming strategies can also be used for disease modelling as patient-derived somatic cells, e.g. skin cell can be reprogrammed into a neuron either directly or via the stem cell stage (i.e. iPSC). Reprogramming technologies has facilitated the utilization of patient-specific cells (e.g. skin cells) for replicating disease pathology, retaining the genetic background of the patient, and recapitulating key developmental mechanisms.
This thesis involves establishment of new and improved strategy to generate human interneurons by direct reprogramming. Also, we are establishing a disease model of Schizophrenia, utilizing patient specific iPSCs, with differentiation and reprogramming strategies towards GABAergic interneurons in complex co-culture systems. In these we aim to study disease pathology (morphology and functional properties) and compare them to their healthy counterpart.
Preliminary results
We have established a robust reprogramming protocol to GABAergic interneurons using a new 3D culture system. In here the human glia convert into neurons in only 21 days and gradually mature in neuronal function over time. These GABAergic interneurons are of a specific subtype called parvalbumin (PV) and demonstrate subclass specificity as assessed with single-cell sequencing. The reprogramming protocol is assessed in vitro and compared to bona fide interneurons. We also demonstrate that cells follow a distinct gene regulatory pathway during glia-to-PV reprogramming. Upon transplantation to the immunodeficient mouse the human interneurons can survive and integrate into the host brain, developing elaborate morphologies and showing functionality.
We have also established protocols for stem cell differentiation to GABAergic interneurons of another subtype and are currently running the differentiation with patient-derived cells. We except to see some aspects of disease pathology, such as decreased number of subtype specific neurons, altered morphology and NMDA hypofunction.
Significance
To create successful and robust reprogramming protocols for generating PV interneurons could be of great importance for future cell replacement strategies for neurological disorders, such as schizophrenia and Alzheimer’s disease. This therapy could be generated in vivo and have great potential for restoring also the impaired synaptic plasticity. Furthermore, the establishment of robust in vitro disease model is of great importance for studying key developmental mechanisms in disease pathology and serving as platform for drug screening.
Om evenemanget
Plats:
Room E11047
Kontakt:
christina-anastasia [dot] stamouli [at] med [dot] lu [dot] se