A tiny brain component may be the key to anti-ageing treatments, researchers say

A vital pea-sized component of the brain may be the key to holding back ageing and extending human lifespan, research suggests.

The hypothalamus, a small bundle of neurons at the base of the brain, governs how quickly the body ages, scientists have learned.

Tests on laboratory mice pinpointed ageing control to a tiny population of adult stem cells within the brain region.

Humans are likely to respond to the influence of hypothalamus stem cells in just the same way, the scientists believe.

Lead investigator Professor Dongsheng Cai, from Albert Einstein College of Medicine in New York City, said: “Our research shows that the number of hypothalamic neural stem cells naturally declines over the life of the animal, and this decline accelerates ageing.

“But we also found that the effects of this loss are not irreversible. By replenishing these stem cells or the molecules they produce, it’s possible to slow and even reverse various aspects of ageing throughout the body.”

(Ben Birchall/PA)

The hypothalamus acts like a computer’s CPU (central processing unit), regulating a wide range of biological functions in the body and linking nerves and hormones.

One of its most important jobs is to maintain homeostasis – keeping different parts of the body working in a constantly stable, balanced way.

Among the many body functions it influences are temperature control, appetite, blood pressure, heart rate, sleep cycles, sex drive and digestion. It operates via a complex array of hormones.

The crucial hypothalamus stem cells are “mother cells” that mature to produce new neurons.

Prof Cai’s team of researchers, whose findings are reported in the journal Nature, looked at what happened to the cells as healthy mice got older.

They found that the number of hypothalamus stem cells began to diminish when the animals reached about 10 months, several months before the usual signs of ageing normally start to appear. Mice in captivity live a maximum of only about two to three years.

When the stem cells in middle aged mice were selectively disrupted artificially, it led to “greatly accelerated ageing”, said the professor.

He added: “Those mice with disrupted stem cells died earlier than normal.”

The next step was to inject hypothalamus stem cells into the brains of mice whose own supply of the cells had been destroyed, as well as “normal” old mice.

In both groups of animals, various measurements including tissue analysis and assessments of muscle endurance, co-ordination, social behaviour and mental ability, showed that ageing was either slowed or reversed.

These small snippets of genetic material play a key role in regulating gene activity. By pairing up with “messenger” RNA molecules, which carry genetic code instructions to protein-building machinery in cells, they can effectively switch off certain genes.

When miRNA was extracted from hypothalamus stem cells and injected into the cerebrospinal fluid of mice, ageing was once again significantly slowed.

As a first step towards new anti-ageing treatments, the scientists are now trying to identify specific populations of anti-ageing microRNAs and possibly other secretions from hypothalamus stem cells that may play a role.