The teenage hormone that triggers puberty and prevents cancer

The appropriately named kisspeptin was discovered by accident, and has some surprising effects.

Whatever your parents told you, it’s not about the birds and the bees. Ultimately, reproduction seems to be about a protein molecule called kisspeptin. The name has nothing to do with foreplay, however. Kisspeptin was discovered in Hershey, Pennsylvania, and its name comes from the town’s other great research success: Hershey’s Kisses chocolates.

At some point, most people’s brain starts to secrete kisspeptin; when it does, the hypothalamus begins to produce a chemical called gonadotropin-releasing hormone, or GnRH. Written down, it looks like a teenage grunt and that’s what it leads to. GnRH release is a crucial moment at the beginning of puberty. It brings about the secretion of hormones that start egg or sperm production and create the characteristic signs of sexual maturity.

On 12 September, the King’s College London professor Kevin O’Byrne discussed the “enigma” of GnRH at a conference at the University of Bristol. The central enigma is the unanswered question of what kicks off puberty – we still don’t know what activates kisspeptin to release GnRH.

It seems to have something to do with the brain’s monitoring of stress and nutrition. Without good fat reserves and a relaxed demeanour, the chemical sages won’t let you enter the trials of reproduction. That’s why girls suffering from anorexia can experience disrupted menstruation.

Kisspeptin’s role in puberty was discovered by accident when researchers were looking at its anti-cancer properties. Controlling the teenage brain is not the only thing it can do. GnRH is now used as a part of some cancer treatment routines because it stops the production of oestrogen, a hormone that seems to play a role in stimulating tumour growth.

Here’s another clue: some of the ugliest rodents on the planet, known as “naked mole rats”, are awash with kisspeptin – and they don’t get cancer.

Most animals have levels of kisspeptin neurons that vary according to sex as well as reproductive state. New research shows that naked mole rats have high kisspeptin and GnRH levels no matter what their readiness for reproduction.

That is particularly odd because, despite these high levels of kisspeptin, most naked mole rats don’t develop the ability to breed. Like some species of bee, naked mole rats live in colonies in which only a queen and a few consorts develop the ability to reproduce. The rest are workers that remain sterile all their lives. And those are long lives.

Their extraordinary resistance to developing cancers makes naked mole rats the longestliving rodents. Mice and rats typically live for two or three years; naked mole rats often live for two decades or more. Understanding what kisspeptin does for the naked mole rat could assist our fight against the ravages of ageing.

However, our slowly increasing grasp of kisspeptin and GnRH is causing a dilemma. The age at which human beings hit puberty is falling – on average, it has fallen by five years since 1920. It’s less of a problem for boys than for girls, for whom “precocious puberty” is linked with an increased risk of breast cancer, mental disorders and, in later life, polycystic ovary syndrome.

That raises the question of whether we should intervene. There’s still a lot we don’t know but research has shown that an injection of kisspeptin kicks off puberty artificially. More usefully, drugs that block kisspeptin prevent puberty from starting and doctors are starting to intervene in the most extreme cases of precocious puberty. Some see this as a risky thing to do when we have no long-term data on the outcome.

This new branch of science might not yet have hit puberty but it is already starting to give us trouble.

Teenage kicks: Kisspeptin not only triggers puberty but also helps fight cancer

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 23 September 2013 issue of the New Statesman, Can Miliband speak for England?

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The answer to the antibiotics crisis might be inside your nose

The medical weapons we have equipped ourselves with are losing their power. But scientists scent an answer. 

They say there’s a hero in everyone. It turns out that actually, it resides within only about ten percent of us. Staphylococcus lugdunensis may be the species of bacteria that we arguably don’t deserve, but it is the one that we need.

Recently, experts have cautioned that we may be on the cusp of a post-antibiotic era. In fact, less than a month ago, the US Centres for Disease Control and Prevention released a report on a woman who died from a "pan-resistant" disease – one that survived the use of all available antibiotics. Back in 1945, the discoverer of penicillin, Alexander Fleming, warned during his Nobel Prize acceptance speech against the misuse of antibiotics. More recently, Britain's Chief Medical Officer Professor Dame Sally Davies has referred to anti-microbial resistance as “the greatest future threat to our civilisation”.

However, hope has appeared in the form of "lugdunin", a compound secreted by a species of bacteria found in a rather unlikely location – the human nose.

Governments and health campaigners alike may be assisted by a discovery by researchers at the University of Tubingen in Germany. According to a study published in Nature, the researchers had been studying Staphylococcus aureus. This is the bacteria which is responsible for so-called "superbug": MRSA. A strain of MRSA bacteria is not particularly virulent, but crucially, it is not susceptible to common antibiotics. This means that MRSA spreads quickly from crowded locations where residents have weaker immune systems, such as hospitals, before becoming endemic in the wider local community. In the UK, MRSA is a factor in hundreds of deaths a year. 

The researchers in question were investigating why S. aureus is not present in the noses of some people. They discovered that another bacteria, S. lugdunensis, was especially effective at wiping out its opposition, even MRSA. The researchers named the compound created and released by the S. lugdunensis "lugdunin".

In the animal testing stage, the researchers observed that the presence of lugdunin was successful in radically reducing and sometimes purging the infection. The researchers subsequently collected nasal swabs from 187 hospital patients, and found S. aureus on roughly a third of the swabs, and S. lugdunensis on up to 10 per cent of them. In accordance with previous results, samples that contained both species saw an 80 per cent decrease of the S. aureus population, in comparison to those without lugdunin.

Most notably, the in vitro (laboratory) testing phase provided evidence that the new discovery is also useful in eliminating other kinds of superbugs, none of which seemed to develop resistance to the new compound. The authors of the study hypothesised that lugdunin had evolved  “for the purpose of bacterial elimination in the human organism, implying that it is optimised for efficacy and tolerance at its physiological site of action". How it works, though, is not fully understood. 

The discovery of lugdunin as a potential new treatment is a breakthrough on its own. But that is not the end of the story. It holds implications for “a new concept of finding antibiotics”, according to Andreas Peschel, one of the bacteriologists behind the discovery.

The development of antibiotics has drastically slowed in recent years. In the last 50 years, only two new classes of this category of medication have been released to the market. This is due to the fact almost all antibiotics in use are derived from soil bacteria. By contrast, the new findings record the first occurrence of a strain of bacteria that exists within human bodies. Some researchers now suggest that the more hostile the environment to bacterial growth, the more likely it may be for novel antibiotics to be found. This could open up a new list of potential areas in which antibiotic research may be carried out.

When it comes to beating MRSA, there is hope that lugdunin will be our next great weapon. Peschel and his fellow collaborators are in talks with various companies about developing a medical treatment that uses lugdunin.

Meanwhile, in September 2016, the United Nations committed itself to opposing the spread of antibiotic resistance. Of the many points to which the UN signatories have agreed, possibly the most significant is their commitment to “encourage innovative ways to develop new antibiotics”. 

The initiative has the scope to achieve a lot, or dissolve into box ticking exercise. The discovery of lugdunin may well be the spark that drives it forward. Nothing to sniff about that. 

Anjuli R. K. Shere is a 2016/17 Wellcome Scholar and science intern at the New Statesman