Alexander Rauch

Alexander Rauch

Who causes the trouble when it comes to osteoporosis?

‘It makes good sense to use a football analogy if you’re trying to give a clear explanation of why it’s so difficult to understand the details of the biology underlying osteoporosis,’ says Alexander Rauch.

He holds a PhD in molecular biology and is assistant professor at the Department of Medical Endocrinology at the University of Southern Denmark (SDU). For some years now, he has studied the biology of our bones in order to gain an understanding of osteoporosis.

Alexander Rauch was also named a Lundbeck Foundation Fellow in 2020, and he will now use his fellowship to establish his own research group at SDU.

The first task for the research group is to try to discover more about the stem cells in bone marrow that help regenerate bone. And, as Alexander Rauch explains, this is where the football analogy comes in:

‘A number of – presumably very different – stem cells in bone marrow are involved in bone regeneration. They work together to do this, pretty much like the players on a football team work together to do their job. The thing is, we don’t know how many different stem cells – ‘players’ – are in action when it comes to bone regeneration. And we don’t know what each of the different cells does. So, these are some of the first questions we need to investigate further,’ says Alexander Rauch.

Osteoporosis results when we naturally lose bone mass as we age, and our bones become weaker. The actual loss of bone mass is unnoticeable and, therefore, the problem does not usually become obvious until someone breaks a bone, usually after retirement age.

‘On average, one in two women will break a bone during the course of their lives due to osteoporosis; in men, this number is one in five,’ Alexander Rauch explains.

This major difference is partly due to the concentration of sex hormones, since women experience a dramatic decline in oestrogen during the menopause but men produce testosterone even at an advanced age.

In order to gain a clearer picture of the ‘players’ on the bone regeneration team – as well as both their individual and their collective tasks – the research group will begin by analysing the genetic expression of a range of bone marrow stem cells taken from healthy subjects. These samples will then be compared with similar analyses of cells taken from individuals who suffer from osteoporosis. Alexander Rauch adds:

‘In this way, we hope to be able to detect whether osteoporosis changes its ‘line-up’; that is, whether it makes changes to the mix of bone regenerating stem cells. This knowledge could, for instance, be useful when designing cell therapy for treating osteoporosis, and it may in time also help identify prophylactic treatments for the disease.’