The 2021 EASO Friedrich Wassermann Award: Professor Hans Hauner

The 2021 EASO Friedrich Wassermann Award: Professor Hans Hauner

The 2021 EASO Friedrich Wassermann Award, that recognises a lifetime of achievement in obesity research, has been awarded to Professor Hans Hauner of the Technical University of Munich, Germany. Here we find out more about his extensive career and studies into many different issues related to obesity.

Q: Welcome to ECO2021 Hans. Congratulations on this award, which we like to call a ‘lifetime achievement award’ in obesity research. How does it feel to be recognised by your peers in this way?

A: I was very happy when I got this message and I feel very honoured to receive this prestigious EASO award. I still remember the meeting in Jerusalem 1986 very well, when EASO was founded, and I have a special relationship to this great organisation with its impressive achievements since that time.

Q: How did you first become interested in endocrinology and obesity research?

A: My interest started when I studied medicine. I was fascinated by the complex regulation of human metabolism, how our body is able to select and utilise nutrients and how these mechanisms affect human health.

Q: In 1987, you described for the first time the in vitro differentiation of human adipocyte precursors – how important was this study, for both biology and your career?

A: In those years, the culture conditions developed in rodent studies did not work for human cells. However, we found that the addition of glucocorticoids significantly promoted human fat cell development. Our studies also showed that the presence of 10 % fetal calf serum in the cell culture medium as used in those days was strongly inhibitory to fat cell development in stromal-vascular cells from human adipose tissue. This became particularly obvious when we used the serum-free medium introduced by the group of Gerard Ailhaud from Nice. My impression is that this method is still widely used in obesity research.

Q: You have also published extensively on the characterization of genetic risk loci for obesity and diabetes, in journals such as Cell and NEJM. What were some of the most important things to emerge from these studies?

A: The powerful new technology of genome-wide association studies led to the discovery of numerous novel genetic loci in relation to diseases and other phenotypes. However, the true challenge was that the reported tagging SNPs (“single nucleotide polymorphisms”) were in close neighbourhood to numerous other SNPs. Thus, the big question arising was which SNPs are really disease-relevant and by which mechanisms. Furthermore, the majority of SNPs were located in the non-encoding areas of the genome and, therefore, involved in the regulation of gene expression.

We were interested to functionally characterise newly discovered SNPs in relation to obesity and type 2 diabetes. In collaboration with Thomas Illig, from the Helmholtz Center Munich, we planned a large programme and I was lucky to recruit Melina Claussnitzer as a PhD student for this ambitious and risky project. She was smart enough to develop a novel bioinformatic approach that exploits the evolutionary conservation of complex transcription factor binding sites in clusters of transcriptional activity across species that we called “phylogenetic module complexity analysis” or PMCA. We selected the PPARG gene locus as a showcase, applied PMCA and performed a comprehensive biochemical validation to elucidate the underlying diabetes-related mechanism.

It was even more challenging to study the FTO gene locus and Melina, already as a guest scientist at the Broad Institute in Boston, further refined the workflow and included epigenomic data from the Roadmap Epigenomics and ENCODE consortia. We found that the causal rs1421085 T-to-C variant disrupts a motif for the transcription factor ARID5B leading to a developmental shift from energy-dissipating beige adipocytes to energy-storing white adipocytes in human adipose tissue.

Q: More recently, you have been involved in several studies into maternal and child obesity and its prevention. The INFAT study, for example, aimed to examine the potential of increasing n-3 fatty acid intake during pregnancy on adipose tissue development in newborns for the primary prevention of childhood obesity. What were the main findings of this research?

A: In this study we wanted to examine if lowering of the n-6/n-LC-PUFS ratio in the maternal diet can reduce the risk of childhood obesity, based on evidence from studies in rodents. However, we could not see an effect of this intervention on the fat mass and other growth trajectories of the children up to the age of 5 suggesting that findings from basic research cannot be simply transferred to the situation in humans.

Q: In 2019, you led on the GeLiS trial, which aimed to avoid excessive gestational weight gain during pregnancy and to prevent childhood obesity (BMC Medicine 2019). Was this study successful? How big a challenge is the world to ensure mothers can maintain a healthy weight in pregnancy, for the benefit of themselves and their children?

A: After a pilot study that showed that excessive weight gain during pregnancy can be prevented by targeted lifestyle counselling we performed a large-scale lifestyle intervention study in routine care. Unfortunately, it turned out that lifestyle modification is hard to achieve in the “real world” and had little effect. Thus, current efforts for a primary prevention of childhood obesity are not successful, as we also found in a recent comprehensive meta-analysis.

Q: How do you think the obesity pandemic will develop in the next two decades?

A: I expect that the obesity epidemic will not be stopped unless we are able to change our lifestyles around the globe. We will certainly need fundamental changes to improve our diet and lifestyle at the societal levels. It is particularly the “toxic food environment” and the unlimited promotion of highly processed food and energy-rich beverages as well as the general lack of physical activity in our daily life. However, I hope and I am optimistic that the push from the climate change initiatives will also facilitate a more responsible debate how we eat and what we eat.

Q: Which sessions would you like to attend at this year’s congress?

A: As always, the programme is rather broad and informative with many current topics. I usually select from all fields and enjoy to get a lot of updates and inspiration from basic science up to public health aspects. 

Q: And finally, when you are not in ‘work’ mode, how do you like to relax?

A: I love to do hiking, biking, jogging and playing tennis, but I also enjoy cultural events of any type and reading books on various topics.

Thank you Hans, many congratulations on your award and enjoy the congress.