Epigenetic marks influence genes usage. This machinery controls how many of each protein or RNA molecules cell produces. This is why neuron and epithelial cell care the same DNA in their nucleus but look differently.
People ask me how they can change their own epigenetics. First of all let’s see what affects on human epigenetics across lifespan.
So if you want change your epigenetics- just change your lifestyle. If you’re too lazy for this there’s another way.
Article that was published in Cell by Shawn Liu and co-authors, Sep 2016 described the system for editing DNA methylation in the mammalian genome. For example, cell doesn’t produce protein if gene is highly methylated. Researchers from MIT and their collaborators mutated Cas9 protein to let interactions between it and methylation (Dnmt3a) or demyelination (Tet1) factors. We heard about the Cas9 from the well known CRISPR/Cas9 genome editing tool.
Cas9 is responsible for targeting. Dnmt3a and Tet1 are effector proteins- they remove and add methyls to cytosine in DNA.
This is how it works:
mC- methylated Cytosine (base in DNA). GFP- green fluorescent protein. It responsibles for cell fluorescence.
A. If you add the methylation to GFP gene especially to regulating element cell stops to fluoresce. Researchers did this using Dnmt-Cas9 system.
B. Removing of the methylation with Tet-Cas9 allows green fluorescent protein production. And cell starts to fluoresce.
Cas9 associates with special literally “guide” RNA. This RNA assists in binding exactly right place in genome. Researchers can easily synthesize new types of RNA and change the target.
Imagine the Cas9-Dnmt3a-Tet1 protein system as the iPhone and guide RNA as an app in the AppStore. Ones you buy it you can freely download endless number of programs with different functions.
Researchers changed the green fluorescent protein- guided RNA to another guided RNA. So they successfully turned off and on different genes in mouse: BDNF, CTCF gene motifs and others.
Several more years would be required however to make this system common in humans. I think that epigenome editing could have less dramatic effects in future generations than genome editing. Nevertheless methylation/demethylation tool demonstrated their wide utility for lab studies.