Brain Gene Expression in a Novel Mouse Model of Postpartum Mood Disorder

Estrogen sulfotransferase and sulfatase in steroid homeostasis, metabolic disease, and cancer

Sulfation and desulfation of steroids are opposing processes that regulate the activation, metabolism, excretion, and storage of steroids, which account for steroid homeostasis. Steroid sulfation and desulfation are catalyzed by cytosolic sulfotransferase and steroid sulfatase, respectively. By modifying and regulating steroids, cytosolic sulfotransferase (SULT) and steroid sulfatase (STS) are also involved in the pathophysiology of steroid-related diseases, such as hormonal dysregulation, metabolic disease, and cancer. The estrogen sulfotransferase (EST, or SULT1E1) is a typical member of the steroid SULTs. This review is aimed to summarize the roles of SULT1E1 and STS in steroid homeostasis and steroid-related diseases.

Characterising heart rhythm abnormalities associated with Xp22.31 deletion

BACKGROUND

Genetic deletions at Xp22.31 are associated with the skin condition X linked ichthyosis (XLI), and with a substantially increased risk of atrial fibrillation/flutter (AF), in males. AF is associated with elevated thrombosis, heart failure, stroke and dementia risk.

METHODS

Through: (a) examining deletion carriers with a diagnosis of AF in UK Biobank, (b) undertaking an online survey regarding abnormal heart rhythms (AHRs) in men/boys with XLI and female carriers of XLI-associated deletions and (c) screening for association between common genetic variants within Xp22.31 and idiopathic AF-related conditions in UK Biobank, we have investigated how AHRs manifest in deletion carriers, and have identified associated risk factors/comorbidities and candidate gene(s). Finally, we examined attitudes towards heart screening in deletion carriers.

RESULTS

We show that AHRs may affect up to 35% of deletion carriers (compared with <20% of age-matched non-carriers), show no consistent pattern of onset but may be precipitated by stress, and typically resolve quickly and respond well to intervention. Gastrointestinal (GI) conditions and asthma/anaemia were the most strongly associated comorbidities in male and female deletion carriers with AHR, respectively. Genetic analysis indicated significant enrichment of common AF risk variants around STS (7 065 298-7 272 682 bp in GRCh37/hg19 genome build) in males, and of common GI disorder and asthma/anaemia risk variants around PNPLA4 (7 866 804-7 895 780 bp) in males and females, respectively. Deletion carriers were overwhelmingly in favour of cardiac screening implementation.

CONCLUSION

Our data suggest AHRs are frequently associated with Xp22.31 deletion, and highlight subgroups of deletion carriers that may be prioritised for screening. Examining cardiac function further in deletion carriers, and in model systems lacking steroid sulfatase, may clarify AF pathophysiology.

Sex-linked genetic mechanisms and atrial fibrillation risk

Atrial fibrillation (AF) is a cardiac condition characterised by an irregular heartbeat, atrial pathology and an elevated downstream risk of thrombosis and heart failure, as well as neurological sequelae including stroke and dementia. The prevalence and presentation of, risk factors for, and therapeutic responses to, AF differ by sex, and this sex bias may be partially explained in terms of genetics. Here, we consider four sex-linked genetic mechanisms that may influence sex-biased phenotypes related to AF and provide examples of each: X-linked gene dosage, X-linked genomic imprinting, sex-biased autosomal gene expression, and male-limited Y-linked gene expression. We highlight novel candidate risk genes and pathways that warrant further investigation in clinical and preclinical studies. Understanding the biological basis of sex differences in AF should allow better prediction of disease risk, identification of novel risk/protective factors, and the development of more effective sex-tailored interventions.

Steroid sulfatase inhibitors: the current landscape

Introduction: Steroid sulfatase (STS) enzyme is responsible for transforming the inactive sulfate metabolites of steroid sex hormones into the active free steroids. Both the deficiency and the over-expression of STS are associated with the pathophysiology of certain diseases. This article provides the readership with a comprehensive review about STS enzyme and its recently reported inhibitors.Areas covered: In the present article, we reviewed the structure, location, and substrates of STS enzyme, physiological functions of STS, and disease states related to over-expression or deficiency of STS enzyme. STS inhibitors reported during the last five years (2016-present) have been reviewed as well.Expert opinion: Irosustat is the most successful STS inhibitor drug candidate so far. It is currently under investigation in clinical trials for treatment of estrogen-dependent breast cancer. Non-steroidal sulfamate is the most favorable scaffold for STS inhibitor design. They can be beneficial for the treatment of hormone-dependent cancers and neurodegenerative disorders without significant estrogenic side effects. Moreover, dual-acting molecules (inhibitors of STS + another synergistic mechanism) can be therapeutically efficient.

A new molecular risk pathway for postpartum mood disorders: clues from steroid sulfatase-deficient individuals

Postpartum mood disorders develop shortly after childbirth in a significant proportion of women. These conditions are associated with a range of symptoms including abnormally high or low mood, irritability, cognitive disorganisation, disrupted sleep, hallucinations/delusions, and occasionally suicidal or infanticidal ideation; if not treated promptly, they can substantially impact upon the mother's health, mother-infant bonding, and family dynamics. The biological precipitants of such disorders remain unclear, although large changes in maternal immune and hormonal physiology following childbirth are likely to play a role. Pharmacological therapies for postpartum mood disorders can be effective, but may be associated with side effects, concerns relating to breastfeeding, and teratogenicity risks when used prophylactically. Furthermore, most of the drugs that are used to treat postpartum mood disorders are the same ones that are used to treat mood episodes during non-postpartum periods. A better understanding of the biological factors predisposing to postpartum mood disorders would allow for rational drug development, and the identification of predictive biomarkers to ensure that 'at risk' mothers receive earlier and more effective clinical management. We describe new findings relating to the role of the enzyme steroid sulfatase in maternal postpartum behavioural processes, and discuss how these point to a novel molecular risk pathway underlying postpartum mood disorders. Specifically, we suggest that aberrant steroid hormone-dependent regulation of neuronal calcium influx via extracellular matrix proteins and membrane receptors involved in responding to the cell's microenvironment might be important. Testing of this hypothesis might identify novel therapeutic targets and predictive biomarkers.