Tremblay, Jacques J. LLB, PhD - Regular researcher

Full professor - Université Laval

(1) Reproduction, mother and child health axis, Centre de recherche du CHU de Québec

(2) Obstetrics, gynaecology and reproduction axis, Faculty of Medicine

Research interest

My research program is at the interface of the endocrinology and cellular and molecular biology fields. We study the molecular mechanisms of Leydig cell differentiation and function. Leydig cells are testis cells involved in the production, among others of the steroid hormone testosterone.  Inadequate levels of steroid hormones are the cause, or at least an aggravating factor, of many human pathologies such as cancers, POCS, endometriosis, auto-immune and inflammatory diseases. Understanding how this system works in normal conditions, by studying Leydig cells, will provide essential information that will ultimately lead to better diagnostics and treatments for these problems.

Although different hormones and signalling molecules are involved in the differentiation and function of Leydig cells, upstream transcription factors of these pathways remain unknown. We have identified various transcription factors, some never before reported in Leydig cells, that are essential regulators of cellular differenciation in other tissues. Some are found exclusively in male gonads, others in the adult population of Leydig cells or even some that are markers of Leydig stem cells. In addition, we have demonstrated the presence of the CAMKI kinase in Leydig cells and its involvement in gene expression following hormone stimulus. Finally, we have identified AMPK kinase as the first molecular stop of steroidogenesis, which has many clinical implications. The targets of these two kinases remain to be identified. Our work on the characterization of the role of these transcription factors and kinases is based on classical molecular and cellular biology approaches, as well as on gene edition, animal models and proteomic, genomic and bioinformatic approaches.    


Leydig cells Gene expression Hormone Intracellular signalling Sexual differenciation

Centre de recherche du CHU de Québec (CHUL)

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