Jacob Kimmel

It's different combinations and different weights of each of the genes.

And so most of them are targeting pretty broad programs.

And there are no guarantees that aging actually involves moving perfectly along any of the vectors in this particular basis set.

And so it's probably going to be a little tricky to figure out a combination that actually takes you backward.

There's, again, no guarantees from evolution that it's just a simple reset.

And so it's actually a critical part of the process that we run through as we try and discover these medicinal combinations of transcription factors we can turn on is to ensure that they not only are making an age cell revert to a younger state.

We measure that a couple different ways.

One is simply measuring which genes those cells are using.

They use different genes as they get older.

You can measure that just by sequencing all of the mRNAs, which are really the expressed form of the genes being utilized in the genome at a given time.

You see that age cells use different genes.

Can I revert them back to a younger state?

Colloquially, we call this a looks-like assay.

Can I make an old cell look like a young one based on the genes it's using?

And maybe more importantly, we go down and drill to the functional level.

And we measure, can I actually make an age cell perform its functions, its object roles within the body, the same way a young cell would?

And these are the really critical things you care about for treating diseases.

Can I make a hepatocyte, a liver cell in Greek, function better in your liver so it's able to process metabolites like the foods you eat, how it's able to process toxins like alcohol and caffeine?

Can I make a T cell respond to pathogens and other antigens that are presented within your body?

So these are the ways in which we measure age, and so we need to ensure that not only does the combination of TFs that we find actually have positive effects along those axes, but we then want to also measure any potential detrimental effects of that image.