Epigenetic regulation of neuronal plasticity
Lead Research Organisation:
University of Nottingham
Department Name: School of Life Sciences
Abstract
Neuroepigenetics is a growing field that aims to examine the molecular processes which dynamically modulate gene expression within the nervous system. DNA methylation, a form of epigenetic modification, alters as we age (Keleshian et al, J Neurochem. 2013. 125:63-73; Su et al, Nat Neurosci. 2012. 15(8):1061-2). As such, it is thought that DNA methylation may contribute to reduced plasticity and regenerative ability of the aged central nervous system (CNS) when compared to the juvenile, adolescent, or adult brain (Li et al, Nat Neurosci. 2010 Dec;13(12):1496-504).
Understanding how the methylation profile of the brain changes as we age may lead to the ability to prevent cognitive decline and manipulate recovery in adults and older patients if they suffer from a CNS injury. The first phase of this project involves cell culture experiments, which examine how preventing different steps in the DNA methylation / de-methylation process affects axon growth before and after injury. Enzymes required for methylation and de-methylation are inhibited in culture and the effect on neuronal outgrowth and repair is assessed. We then wish to examine how these different forms of DNA methylation are altered due to aging in neurons within the adult brain, and using Fluorescence-activated cell sorting, methylated DNA immunoprecipitation and qPCR to investigate the methylation of genes which have already been linked to changes in neuronal plasticity in the aged brain (Li et al, Nat Neurosci. 2010. 13(12): 1496-1504.), directly comparing young adults (4 months) and aged mice (20 months). Changes in these markers will be correlated with in-depth behavioural characterisation of cognitive functions, dendrite formation (via Golgi staining) and levels of synaptic markers (via immunohistochemistry).
From these in vitro and in vivo studies we then aim to identify which step/s of the DNA methylation / de-methylation process it may be beneficial to target, to reduce decline with age, but also to improve recovery in older people when they suffer an acute CNS injury, such as stroke.
Understanding how the methylation profile of the brain changes as we age may lead to the ability to prevent cognitive decline and manipulate recovery in adults and older patients if they suffer from a CNS injury. The first phase of this project involves cell culture experiments, which examine how preventing different steps in the DNA methylation / de-methylation process affects axon growth before and after injury. Enzymes required for methylation and de-methylation are inhibited in culture and the effect on neuronal outgrowth and repair is assessed. We then wish to examine how these different forms of DNA methylation are altered due to aging in neurons within the adult brain, and using Fluorescence-activated cell sorting, methylated DNA immunoprecipitation and qPCR to investigate the methylation of genes which have already been linked to changes in neuronal plasticity in the aged brain (Li et al, Nat Neurosci. 2010. 13(12): 1496-1504.), directly comparing young adults (4 months) and aged mice (20 months). Changes in these markers will be correlated with in-depth behavioural characterisation of cognitive functions, dendrite formation (via Golgi staining) and levels of synaptic markers (via immunohistochemistry).
From these in vitro and in vivo studies we then aim to identify which step/s of the DNA methylation / de-methylation process it may be beneficial to target, to reduce decline with age, but also to improve recovery in older people when they suffer an acute CNS injury, such as stroke.
Organisations
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| BB/M008770/1 | 01/10/2015 | 31/10/2024 | |||
| 1647921 | Studentship | BB/M008770/1 | 01/10/2015 | 31/10/2019 |
| Description | The work funded through this award has helped to identify a role of DNA hydroxymethylation in axon growth that both consolidates and develops upon previously published research. An in vitro model was used to assess the role of this epigenetic mechanism in regulating axonal growth. By manipulating the levels of the enzymes responsible for producing hydroxymethylation, and assessing axon lengths, we determined that knockdown of TET2 and TET3 significantly decreased axon growth, and overexpression of TET3 increased axonal growth. Previous findings in peripheral nerves support this. To see how a pathological condition may induce this mechanism to enhance axonal regrowth and repair, we looked at ischemia. Hypoxia in this in vitro model induced expression of TET3, and it was determined that levels of 5-hydroxymethylcytosine are increased in the brain following stroke, with these increases peaking at 2-7 days and returning to normal after 1 month. This consolidates the findings of previously published research (Miao et al., Human molecular genetics 24.20 (2015): 5855-5866; Morris-Blanco et al., Stroke 50.9 (2019): 2513-2521) and could be a mechanism through which ischemia is increasing axonal growth to repair the brain after stroke. Ultimately, it is hoped that these findings, and any potential future research in this area, can lead to the development of a novel therapeutic treatment for brain injuries. This work is being prepared for publication. |
| Exploitation Route | The findings generated from the work funded through this award have opened up numerous research questions (i.e. which particular genes are being affected by changes in 5hmC? Can altering 5hmC in an in vivo model of ischemic stroke lead to improved functional recovery?). It is hoped that these questions can provide the basis for future academic or industrial research, with the ultimate aim of developing a therapeutic treatment for ischemic stroke that utilises the brain's intrinsic epigenetic response. In terms of non-academic routes, the outcomes of this funding could be used in public outreach events to help further highlight the need for developing novel ischemic stroke treatments. Previous outreach events that displayed the research funded by this award (such as the Pint of Science festival and presentations to recovering stroke patients) have generated great interest and positive feedback, demonstrating a great interest in this area of research. |
| Sectors | Healthcare |
| Description | Pint of Science Festival, Nottingham |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Public/other audiences |
| Results and Impact | At the Pint of Science festival in Nottingham, I was part of the team organising the "Beautiful Mind" events. This consisted of 3 events over 3 nights, each with an audience of 100 members of the general public. As part of this event, I ran an activity which involved showing members of the general public how to work a light microscope and showed them some slides of immuno-stained brain sections from my own project. As they were engaging in the activity, I also briefed them on the outline of my project and some of the key findings, which usually sparked interest and invited more questions. Feedback forms from the 3 nights of the festival showed that audience members left with an increased interest in neuroscience and the neuroscience research that happens in the universities local to them. |
| Year(s) Of Engagement Activity | 2017,2018 |
| URL | http://pintofscience.co.uk |