Jacques J. TremblayM.Sc., Ph.D., LL.B.

Dr. Tremblay is a scientist in the Reproduction, Mother and Child Health axis of the Centre de recherche du CHU de Québec—Laval University, and Full Professor in Laval University’s School of Medicine Department of Obstetrics, Gynecology and Reproduction. His research focuses on the study of various facets of Leydig cells, cells that belong to the endocrine system, with applications for disorders of sexual development, hormone-dependent diseases, cell differentiation, as well as the regulation of gene expression.

In 2013, Dr. Tremblay was awarded the prestigious Young Andrologist Award from the American Society of Andrology for his contribution to the field of andrology.

Dr. Tremblay’s research program is at the interface of endocrinology and cellular and molecular biology. His team studies the molecular mechanisms of Leydig cell differentiation and function. Leydig cells are testicular cells involved in the production of the steroid hormone, testosterone. Inadequate levels of steroid hormones are a cause, or at least an aggravating factor, of many human pathologies such as cancers, PCOS, endometriosis, and autoimmune and inflammatory diseases. In addition to male reproductive health, sufficient testosterone levels are essential for male general health. Understanding how this system works in normal conditions by studying Leydig cells, will provide essential information that will ultimately lead to better diagnoses and treatments for these problems.

Although different hormones and signalling molecules are involved in the differentiation and function of Leydig cells, the transcription factors downstream of these pathways remain unknown. His team has identified various transcription factors, some never reported in Leydig cells, which are essential regulators of cell differentiation in other tissues. Some are found exclusively in the male gonad, while others are present specifically in the adult population of Leydig cells, or are unique markers of Leydig stem cells. In addition, they have demonstrated the presence of the CAMKI kinase in Leydig cells, and its involvement in gene expression following hormonal stimulation. Finally, they have identified the AMPK kinase as the first molecular brake of steroidogenesis, which has many clinical implications. The targets of these two kinases are yet to be identified. Their work on the characterization of the role of these transcription factors and kinases involves classical molecular and cellular biology approaches, as well as gene editing, animal models and proteomic, genomic and bioinformatics.