Jacob Kimmel

This is mostly examples taken from a wonderful book by Frederick Applebaum who trained with Don Thomas, the physician who invented human bone marrow transplants.

There are many circumstances where patients got a bone marrow transplant and actually cured another disease they had as a result, maybe unanticipated, where it's even just the replacement of this one special cell type, HSCs, has knock-on effects throughout the body.

You know, there were symptoms of these diseases that presented in myriad ways throughout their system, but ultimately its root cause was even just a single cell.

There are counterexamples as well where you can go into animals

and break even just one gene in one specific subset of T cells.

You can break a gene that encodes for a transcription factor in their mitochondria called TREM, and you actually dramatically shorten the lifespan of mice.

One gene in one special type of C cells can give you that type of pathology.

And so it sort of implies the inverse may also exist.

Yeah, I think it's one example because it is a hormone and your endocrine system coordinates a lot of the complex interplay between your tissues.

I don't think the story is fully written yet on exactly why GLP-1 and GIP-1, you know, broadly incretin mimetic medicines like Ozempic have so many knock-on benefits.

But I think they're a great example of this phenomenon.

If someone told you, I'm going to find a single molecule and I'm going to drug it, and it's not only going to have benefits for weight loss, but also for cardiovascular disease, also possibly for addictive behavior, and maybe even preventing neurodegeneration, you would have told them they were crazy.

And yet, just by acting on the small number of cells in your body which are receiving this signal, the interplay and the communication between those cells and the rest of your body seems to have many of these knock-on benefits.

So it's just one existence proof.

Very small numbers of cells in your body can have health benefits everywhere.

And so even if cellular delivery does not emerge by 2100 as I imagine it will, then I still think that you're going to have the ability to add decades of healthy life to individuals by reprogramming the age of individual cell types and individual tissues.

Interesting.

How many transcription factors?

Yeah.

I think just a countable number.