Medical Research

All About Hormones: Endocrinology

27. 7. 2016 | Steroid hormones comprise most sex hormones plus some hormones responsible for stress. Here we present four AcademiaNet researchers who study steroid hormones: Wiebke Arlt, Elisabet Stener-Victorin, Inger Sundström Poromaa and Mirjam Christ-Crain.

Endocrinology is the study of hormones – signalling molecules that regulate physiology, mental wellbeing and behaviour - and the diseases that occur when hormones do not function properly. Steroid hormones have a special role in health and disease, most notably because they control sexual development, but they have many other functions as well. Chemically they differ from other hormones since they're made from cholesterol (a lipid), whereas other hormones are derived from amino acids.

Steroid hormones include the sex hormones testosterone, oestrogen and progesterone, known as sex steroids, and the stress hormone cortisol (a corticosteroid). Steroid hormones control the development of sexual characteristics, as well as influence the immune system, metabolism, blood pressure, and salt and water balance in the body.
Testosterone is the principal male sex hormone, also known as androgens. Androgens are produced primarily by the testes in men, but are also produced in women by the ovaries.

Prof. Wiebke Arlt

Professor Wiebke Arlt, William Withering Chair of Medicine and Director of the Institute of Metabolism and Systems Research at University of Birmingham, UK, studies androgen hormones and their effects in women. Her research group focuses on how the synthesis and action of androgen hormones is controlled at the pre-receptor level. She has discovered that genetic mutations in enzymes that generate co-factors for the synthesis of steroid hormones can cause too much or too little androgen hormones to be produced. Mutations in the two co-factor generating enzymes she has studied - P450 oxidoreductase and PAPS synthase 2 – appear to have a role in androgen excess and the related disorders of sex development in women, such as ambiguous genitalia in female infants and premature puberty in young girls.

Prof. Elisabet Stener-Victorin

In women, androgen excess can also cause polycystic ovary syndrome (PCOS), a disease characterised by irregular periods, excessive hair growth and fertility problems. Professor Elisabet Stener-Victorin, Senior Lecturer and Researcher in the Department of Physiology and Pharmacology at Karolinska Institutet, Sweden, studies the molecular mechanisms underlying this disease. Stener-Victorin's research suggests that the high levels of androgens in mothers with PCOS can increase the number of steroid hormone receptors and steroidogenic enzymes in the placenta during pregnancy. This has the knock-on effect of altering metabolic pathways in the foetus and causing anxiety-like behaviour in the offspring.

These findings suggest that maternal androgen excess in PCOS mothers may increase the risk of anxiety disorders in their offspring via changes in brain function. In her current project, Stener-Victorin is looking at how the combination of maternal obesity and high levels of androgens affect placental and foetal function, and offspring, over several generations. In addition to studying mice models, she works on human studies that investigate global expression profiles of genes and DNA methylation in adipose tissue and fat to gain deeper understanding of the underlying pathophysiology.

Prof. Inger Sundström Poromaa

PCOS is also one of the areas studied by Professor Inger Sundström Poromaa, Professor and Senior Consultant at the Department of Women's and Children's Health in Uppsala University, Sweden. She has researched a large multicentre cohort drawn from across Scandinavia that is evaluating androgen levels throughout life in women with PCOS. This study found that in women with PCOS, androgen levels were raised not only throughout a woman's fertile life, but after menopause too. Prof Sundström Poromaa is involved in another large population-based longitudinal study, which is looking at psychological wellbeing during and after pregnancy in Uppsala County, Sweden (the Biology, Affect, Stress, Imaging, Cognition –BASIC– project).
She and her collaborators have shown that women on treatment for antenatal depression have higher levels of corticotrophin-releasing hormone, which may be of relevance for the increased risk of preterm birth in these women. Her research group has also demonstrated that women with postpartum depression have higher levels of the steroid hormone cortisol.

Prof. Mirjam Christ-Crain

Cortisol is one of the hormones studied by Professor Mirjam Christ-Crain, Professor of Endocrinology at University Hospital Basel and Head of the Department of Clinical Research at the University of Basel, Switzerland. Her research has shown that levels of cortisol, and of the hormone copeptin, are raised in people with severe diseases like pneumonia or stroke. The increased hormone levels can give prognostic information about the course of disease beyond that which is given by routinely performed clinical scores.
Today, Prof. Christ-Crain focuses on the hormone vasopressin, which regulates body water. Measuring levels of vasopressin is difficult because of the small size of the molecule and its very short half-life. However, vasopressin levels are mirrored by those of copeptin. Professor Christ-Crain's data show that measurement of copeptin can be used for the differential diagnosis of patients with polyuria-polydipsia syndrome, a condition characterized by abnormally large production of urine and excess thirst. Measurement of copeptin levels can be used for faster diagnosis of these patients and to provide more targeted treatment.
(© AcademiaNet)

Helen Jaques

Medical Research

All About Hormones: Endocrinology

More information

Prof. Dr. Mirjam Christ-Crain

Universitätsspital Basel

Prof. Dr. Wiebke Arlt

University of Birmingham

Prof. Elisabet Stener-Victorin PhD

Karolinska Institutet

Prof. Inger Sundström Poromaa

Uppsala University Hospital

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