Jonàs Juan Mateu

Jonàs Juan-Mateu is a Distinguished Professor at the Department of Medicine and Life Sciences of Universitat Pompeu Fabra and group leader of the of the recently established Transcriptomics of Endocrine Systems and Metabolism lab. Jonàs holds degrees in Biology,Biochemistry and Molecular Biology, and a PhD in Biomedicine from the University of Barcelona. He was trained in clinical and molecular genetics at Hospital Sant Pau in Barcelona. He later transitioned to pancreatic islet biology, diabetes, and RNA regulation during his postdoctoral research at the Université Libre de Bruxelles and the Centre for Genomic Regulation, under the mentorship of Prof.Décio Eizirik, Prof. Juan Valcárcel, and Prof. Manuel Irimia. His research investigates how gene expression regulation—particularly alternative splicing—shapes endocrine cell identity and function, influencing metabolic homeostasis and disease susceptibility. More recently, he has initiated new research lines focused on the evolution of the endocrine pancreas, exploring how gene regulatory programs have contributed to the emergence of specialized hormone-secreting cells and their functional adaptation across species with contrasting metabolic demands.

Pancreatic islets are endocrine micro-organs that play a central role in regulating nutrient utilization by secreting hormones such as insulin and glucagon. The ability of islet cells—particularly insulin-secreting beta cells—to adapt their secretory responses to changing metabolic demands is critical for maintaining blood glucose levels. Failure of these adaptive mechanisms leads to diabetes, a chronic disease that has reached epidemic proportions in modern populations. Different types of dietary nutrients trigger distinct insulin responses, suggesting that evolutionary adaptations to diet may have driven changes in islet function and metabolic regulation. However, how pancreatic islets have adapted to dietary shifts at the cellular and molecular levels remains largely unexplored. Moreover, whether genetic variants associated with diabetes risk reflect ancient adaptations to specific diet compositions that have become maladaptive in modern environments remains an open question. To explore these ideas, we will perform cross-species comparative analyses on islet function and gene expression using neotropical bats as an evolutionary model.