J147 is an experimental drug that has been shown to treat Alzheimer’s disease, and it also appears to reverse some aspects of aging. It is also poised to enter human clinical trials in the near future, although how it works has been somewhat of a puzzle.

A new study published in the journal Aging Cell has changed all that, and the results are quite intriguing[1]. Researchers at the Salk Institute have solved the mystery of how J147 works and why it makes old flies, mice, and cells more youthful.

Rejuvenating mitochondria

The drug apparently works because it binds to a protein found in mitochondria, the powerhouses of cells; this, in turn, causes cells to function in a more youthful manner. Mitochondrial dysfunction is one of the hallmarks of aging and is thought to be a key reason why we age and develop age-related diseases[2]. This drug appears, at least partially, to address some of that dysfunction.

Finding the target of J147 was the key to revealing the link between Alzheimer’s disease and the aging process. It was the critical information the researchers needed and was holding the drug back from clinical trials.







Dave Schubert, head of Salk’s Cellular Neurobiology Laboratory, and his team originally developed the J147 drug in 2011. The team screened numerous plant-sourced compounds with the potential to reverse the cellular and molecular signs of aging in the brain. The drug was developed as a modified version of a molecule found in the spice curcumin, a common ingredient in Asian foods such as curry.

Since then, the researchers have shown that J147 can reverse memory deficits, increases the production of brain cells, and slows the progression of Alzheimer’s in mice[3]. However, at that point, they did not understand how J147 worked.

Finding the target

During the new study lead by Dave Schubert and Salk Research Associate Josh Goldberg, the researchers used a number of approaches to find out how J147 worked. They eventually identified that the target of J147 was the mitochondrial protein known as ATP synthase, specifically ATP5A, a subunit of that protein. ATP synthase is involved in the mitochondrial generation of ATP, which cells use for energy.

The researchers demonstrated that by reducing the activity of ATP synthase, they were able to protect neuronal cells from a number of toxicities associated with the aging of the brain. One reason for this neuroprotective effect is thought to be the role of excitotoxicity in neuronal cell damage.







Excitotoxicity is the pathological process by which neurons are damaged and killed by the overactivation of receptors for the excitatory neurotransmitter glutamate. Think of it being a bit like a light switch being turned on and off so rapidly that it ends up causing the light bulb to blow.

Recently, the role of ATP synthase inhibition for neuroprotection against excitotoxic damage was demonstrated in a mouse study[4]. The second study showed that mouse models expressing the human form of mutant ATPase inhibitory factor 1 (hIF1), which causes a sustained inhibition of ATP synthase, were more resilient to neuronal death after excitotoxic damage. This data is consistent with this new J147 study, in which an increase in IF1 in the mice reduced the activity of ATP synthase (specifically ATP5A) and was neuroprotective.

ATP synthase is implicated in aging

ATP synthase has previously been shown to influence aging in C. elegans worms and flies. Given that aging is the greatest risk factor for developing Alzheimer’s disease, it is no surprise that the target of the drug is also involved in the aging process.

The team also revealed that by modulating the activity of ATP synthase, they could influence the levels of ATP and other molecules and were able to encourage healthier, more stable mitochondria during aging. Mice given the compound showed profound changes, appearing to look younger at a cellular and molecular level.







The researchers believe that these results are not only encouraging for the treatment of Alzheimer’s, they suggest that J147 may also be useful in treating other age-related diseases.

“People have always thought that you need separate drugs for Alzheimer’s, Parkinson’s and stroke,” said Dave Schubert. “But it may be that by targeting aging we can treat or slow down many pathological conditions that are old-age-associated.”

With J147 having just completed the FDA required toxicology testing in animals, the next step is phase 1 human clinical trials, and the road to approval begins.

Conclusion

It is very heartening to hear important researchers suggesting that in order to treat age-related diseases, one needs to treat the aging processes themselves. This is the exactly what Dr. Aubrey de Grey and others have been saying for many years. It is good to hear more voices joining the call to tackle age-related diseases at their root: the hallmarks and damages where they all begin.







The process of age-related disease begins long before the familiar signs and diagnoses are made; by targeting the early processes that are not given specific disease names, we might yet defeat horrific diseases, such as Alzheimer’s, which rob us of who we are.

Literature

[1] Joshua Goldberg et al. The mitochondrial ATP synthase is a shared drug target for aging and dementia. Aging Cell, 2018 DOI: 10.1111/acel.12715

[2] López-Otín, C., Blasco, M. A., Partridge, L., Serrano, M., & Kroemer, G. (2013). The hallmarks of aging. Cell, 153(6), 1194-1217.

[3] Prior, M., Dargusch, R., Ehren, J. L., Chiruta, C., & Schubert, D. (2013). The neurotrophic compound J147 reverses cognitive impairment in aged Alzheimer’s disease mice. Alzheimer’s research & therapy, 5(3), 25.

[4] Formentini, L., Pereira, M. P., Sánchez‐Cenizo, L., Santacatterina, F., Lucas, J. J., Navarro, C., … & Cuezva, J. M. (2014). In vivo inhibition of the mitochondrial H+‐ATP synthase in neurons promotes metabolic preconditioning. The EMBO journal, 33(7), 762-778.