Steroid hormones are master regulators of health and well-being with impacts on metabolism, inflammation, stress, cognition and reproduction. Steroids are produced in the gonads and adrenals passing via the blood to target tissues. To date we have focussed on the impact of bioactive steroids such as testosterone and oestradiol that change tissue processes via ligand activated receptors identifying key roles in both normal tissue function and in cancer. In reproductive tissues such as the endometrium we believe ‘intracrinology’ – the local conversion/ metabolism of steroids plays a critical role in fine-tuning tissue-selective activation of inert precursor steroids. Across the life-course, changes in adrenal function influence the bioavailability of the major (inert) circulating pool of androgens – notably DHEA, DHEAS, which provide substrates for synthesis of many bioactive steroids including testosterone but at present our ability to measure these transformations across tissues during the healthspan is very limited (1).
Mass spectrometry (MS) is a highly selective tool for identification and quantitation, with liquid chromatography tandem MS, the gold standard. MS performed on blood and tissue homogenates has provided novel insights into concentrations of steroid metabolites. We have recently achieved a major breakthrough in our ability to understand the impact of steroids on individual cells in complex tissues by developing through MS imaging (MSI) (2,3). As proof of concept we have quantified testosterone and its more active metabolite, DHT, in murine testes tubules. In complementary studies we have used in vitro models to explore the role of intracrine steroid biosynthesis in endometrial function providing evidence that this mechanism for controlling spatial and temporal bioavailability of sex steroids can play a key role in fertility (3).
Hypothesis: Intracrinology plays an essential but poorly understood role in endometrial health and disease.
Aims: to understand how androgen and oestrogen milieu in the endometrium is regulated in health and thus altered in endometrial disorders. Specific aims are to:
1. establish MSI to selectively quantify active and inert steroid isomers in endometrial tissue.
2. validate this approach in primary human cell models, where androgen levels are modulated.
3. profile androgen and oestrogen steroidome in tissues from healthy women and contrast this with those with endometriosis, endometrial hyperplasia or infertility.
Research Training: The student will receive interdisciplinary training in a broad range of methods including: a) in vivo and in vitro studies using endometrial tissues from normal women and those with disorders including infertility and endometriosis, b) methods to detect endogenous steroids in endometrium by MS c) computational chemistry, molecular dynamic modelling and statistical analysis. Studies will be conducted in well-funded laboratories within the Queen’s Medical Research Institute fully equipped for the proposed experiments.