Reacción a "Reactions: klotho protein administration improves memory in aged macaques"

Ageing is the main risk factor for the cognitive decline that accompanies many neurodegenerative diseases. Understanding the factors, including genes and proteins, that are associated with ageing may help to discover new therapeutic targets for these diseases. The klotho protein is one such factor.  

Numerous experimental studies in murine models suggest that increasing the function of the klotho protein (e.g. by systemically administering the protein) may reverse some of the effects of ageing and improve cognition. The question is obvious: can these findings be translated to humans? The human data are observational and it has been observed that some genetic variations of klotho can attenuate cognitive decline.  

The study by Castner et al. investigates klotho in non-human primates and therefore its conclusions - while not definitive - are closer to what would be expected in humans. This is the main novelty of the study. The authors injected low doses of the klotho protein, specifically its soluble fragment, into non-human primates. The memory of these animals improved within 4 hours of klotho administration and the effect lasted for 2 to 3 weeks.  

The results are certainly very promising, but important questions remain open. There is no dose-dependent effect, higher doses of klotho are not associated with improved memory. It would also be important to determine whether the effect of klotho can last beyond 2 to 3 weeks; this is key for treating chronic diseases. Finally, we need to better understand the mechanisms of action of klotho before initiating human trials.