Does gene therapy with klotho or follistatin work against ageing?

Klotho is a protein that naturally declines as you get older. In mice, a deficiency of it leads to accelerated ageing and a shorter lifespan, while higher levels of Klotho actually extend lifespan. That makes it a logical target for therapy, but translating this to humans is a major step.

In cell culture it has already been possible to switch on the Klotho gene using CRISPR, a genetic scissor technique. That proves the approach works in principle, but this is not yet a treatment in humans or even in animals. In mouse models, two more specific applications have now also been tested: a nanoparticle approach in which a single low dose was sufficient to prevent kidney damage and scarring, and a similar system targeting ageing intervertebral discs, in which the disc cells appeared to become healthier again. Both have been studied exclusively in mice.

For the brain, there are multiple animal studies pointing to protective effects of Klotho: better memory, less nerve damage, better recovery of the myelin protective sheath around nerves. Clinical evidence in humans is still entirely absent here. The same applies to broader ageing-related diseases: a review study describes Klotho supplementation as promising, but also warns that the effects are highly context-dependent and that risks and benefits in humans have not been sufficiently studied.

On follistatin gene therapy in ageing, the available sources say absolutely nothing. No conclusions can be drawn on this topic based on this research.

In summary: there is a strong biological rationale for studying Klotho, the first technical steps in cells and mice have been taken, but there are no human clinical data showing that gene therapy with Klotho is safe or effective in people.