Sex-specific disease aetiology from developmental steroid insults: mechanistic understanding and biomarker development towards disease prevention.

We are living and working longer, but capitalising on this means enjoying extended 'healthspan' as well as extended lifespan. Risks of developing many adult illnesses are set down as we develop in the womb, hence the environment we experience during fetal life needs to be 'just right'. Understanding how the fetal environment colours development helps decision making during pregnancy to ensure best health chances for our children.
Hormones drive development. Steroid hormones direct numerous processes, including correct male or female development. Unfortunately, imbalance in sex steroids during development can have lifelong health consequences. Numerous clinical conditions associated with altered early life steroid exposure have effects that are 'silent' until later in life. Some of these consequences are sex-specific, likely due to differing hormonal requirements of male or female development. There are also many chemicals in our environment that can reach a developing fetus. Some of these compounds behave like steroids, or affect natural steroid actions; these are 'endocrine disrupting compounds'.
The sex steroids androgens and oestrogens play critical male and female-specific roles in development. Common conditions such as Polycystic Ovary Syndrome (PCOS) have origins of incorrect sex steroid exposure during development. Endocrine disrupting compounds commonly mimic, or alter, effects of these sex steroids. If we knew what the effects of the incorrect sex steroid exposure were during fetal life, and could connect this information to adult disease development, then we could predict what the effects of chemical exposures, and clinical conditions such as PCOS would have on the next generation. By identifying biomarkers in adult life that are legacies of incorrect fetal steroid exposure, we could identify those individuals at risk of developing associated illness. We could then design treatments to prevent disease prior to its occurrence in at risk individuals, and thereby protect such people from having 'healthspans' shorter than their lifespans.
Whilst investigating origins of PCOS we developed sheep models of this human condition by altering the sex steroid environment that developing lambs experience. This leads to development of insulin resistance, obesity, altered pancreatic and liver function in adulthood. Here we have chosen to study the liver since it responds to, deactivates and transforms steroids. Our work indicated that the liver was affected in a health-relevant manner by our altered fetal steroid exposure studies.
Recent technological advances will let us build 'maps' of effects of altered steroid exposure during fetal life on development and adult function of liver, specific to males and females. As we already know some adult health consequences of altered fetal steroid exposure we can now discover the reasons behind them. Once we know the genes and proteins affected, we can examine the possibility of some alterations in the liver being detectable in the circulation. This will give us blood tests to see if someone has been incorrectly exposed to altered steroid signalling during their early life, and then we can consider how to help such individuals prior to them getting ill. All sheep samples required are already collected from previous scientific investigations, saving time, money, and reducing animal use in research. We know the sheep samples we propose for study are affected in terms of human-relevant health, so these samples hold answers to how these effects occur. We will reveal the consequences of altered sex steroid exposure during development, how such alterations affect adult disease risk, develop blood tests to identify during early life those at increased risk in later life, and provide information regarding possible treatment routes.

Fetal development, including sex development, is modulated by steroids. Incorrect steroid exposure in utero predisposes to altered postnatal disease risk. If we understand the postnatal health legacies that are consequences of excess steroid exposure in utero, we can advise upon issues such as limiting exposure to exogenous compounds that alter steroid signalling, and develop amelioration strategies where exposure is due to underlying medical conditions.
RESEARCH PLAN
We will interrogate, using Next Generation Sequencing and shotgun proteomics, pre-existing sets of ovine tissues, where excess sex steroid signalling was experimentally driven during fetal life to model human PCOS. Due to its modulatory role in steroid exposure during development and postnatal life, the liver is our focus. We capitalise on previous investment in large animal modelling, and require no additional animal experimentation. We add translation to humans by interfacing this work with ongoing work examining the human fetal liver.
DELIVERABLE 1 We will identify hepatic differences in postnatal life attributable to developmental androgenisation in sheep. We will examine the outcomes of steroidal excess during development on male and female postnatal hepatic function. This work will identify postnatal legacies, and fetal antecedents of, disrupted steroid signalling in utero, in a sex-specific context.
DELIVERABLE 2 We will use health relevant indices collected in vivo, to delineate 'effect' from 'adverse effect'. We will utilise human data sets to provide translational confidence between interventional ovine models and observational human studies.
DELIVERABLE 3 We will identify postnatal biomarkers of specific fetal steroid excesses (androgen or oestrogen) in offspring from birth to adulthood that are relevant to health, and deliver mechanistic insights to inform future therapeutic strategies.

The advances made in this project will impact upon, and benefit, research disciplines, spanning basic developmental biology, fetal origins of adult disease and medical research. Medical communities, and individuals will all benefit from the new knowledge generated. We recognise the need for increased understanding of the mechanisms of health programming to occur in tandem with improved identification of at risk individuals and this proposal is driven by the unmet clinical needs of both of these ambitions.
Prenatal steroids affect metabolic development and maturation, and increasing evidence links the prenatal steroid environment to altered lifetime risk of metabolic disease development. This research will map what the effects are during development, and in postnatal life, of in utero sex steroid excess, focussing on the liver as a loci of such effects with relevance to development and lifelong health. We will deliver all information in a sex-specific context, since the outcomes of prenatal steroid alterations are predicated upon sex-specific function, itself driven by endogenous sex steroid exposure. Thus the work entailed will also deliver basic biological information regarding hepatic function differences between males and females that are underwritten by steroids during fetal development. This may have implications beyond the current focus of the project, for example in terms of organ transplantation considerations. By understanding the consequences of in utero steroid excesses (clinical or chemical in origin), and relationships to development of disease in adulthood, then knowledge of the systems affected and how they are affected will have implications for preventative and amelioration therapy approaches. We will identify biomarkers of altered development due to incorrect sex steroid exposures, thus placing us in a position to begin to identify at risk individuals earlier than when first signs of postnatal disease development are evident, with congruent increased understanding of the systems affected and consequences of the early life insult. Collectively, these aspects are all relevant and of benefit to both medical practitioners and researchers.
Our previously collected samples are tied to health indices measured in vivo, and so our proposal will be powered to delineate effects from adverse effects, and will be translated to humans from the ovine models used via inclusion of relevant human samples throughout all analyses.
In summary, we will deliver health relevant biomarkers discernible in fetal life, health relevant biomarkers in adult life caused by fetal steroidal alterations, and the mechanisms of action of excess sex steroids during development which will define the consequences of exposure and direct interventional strategy. Collectively, the knowledge gleaned from these studies will positively contribute to and impact upon future lifelong human health.