Mark Nixon Research Group

Dr Mark Nixon 

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Postdoctoral Research Fellow

Research

Glucocorticoids are critical stress hormones that regulate a number of physiological processes including fuel metabolism and immune modulation. Conditions of overt glucocorticoid excess such as Cushing’s disease or chronic glucocorticoid treatment are associated with significant cardiometabolic abnormalities, including obesity, hyperglycemia, and hypertension. Indeed, while glucocorticoid treatment is a cornerstone in the management of many inflammatory diseases, and glucocorticoid replacement is essential for survival in patients with various forms of adrenal insufficiency, cardiovascular disease risk is increased 6-fold in people exposed to long-term supraphysiological doses of glucocorticoids. Notably, this association is more pronounced in women, highlighting sexually dimorphic responses to glucocorticoid therapy. Moreover, recent human GWAMA data demonstrates that variation in the SERPINA6 (CBG) locus is the key genetic determinant of plasma cortisol levels and a causative pathway in determining cortisol action in adipose tissue, and that genetically-elevated cortisol causally increases the risk of heart disease.

Glucocorticoid excess, particularly in adipose tissue, results in visceral obesity, hyperglycemia, dyslipidemia, and hypertension. Thus, limiting glucocorticoid action in adipose tissue may reduce cardiovascular disease. My overarching research goal is to understand the physiological and pathophysiological mechanisms controlling adipose tissue glucocorticoid exposure.

Profile

I am a BHF Intermediate Research Fellow with an interest in obesity-associated metabolic disorders, including type 2 diabetes and hypertension. I obtained my undergraduate degree in Immunology from the University of Edinburgh before undertaking a PhD at the Centre for Cardiovascular Science with Prof Ruth Andrew examining the role of glucocorticoid metabolism on inflammation. In 2012, I moved to the Integrative Biology and Pharmacology Department at the University of Texas Health Science Center Houston to continue my Postdoctoral training with Prof Rebecca Berdeaux. Here I identified a novel role for the AMPK-related kinase SIK1 in regulating glucose homeostasis in obesity.

In 2014, I joined Prof Brian Walker’s group at the Centre for Cardiovascular Science in Edinburgh and demonstrated a novel role for the transmembrane exporter ABCC1 in regulating adipose tissue glucocorticoid exposure. In 2018, I was awarded a BHF Basic Science Intermediate Research Fellowship to establish my own group in Edinburgh investigating the contribution of CBG cleavage to adipose glucocorticoid delivery in obesity.

Social Media

Follow our work on Twitter @NixonLab

Listen to my group’s work showcased as part of the BHF ‘Live & Ticking’ series 2022 (video segment 19:00-40:00)

For a list of up-to-date publications, please visit:

Mark Nixon's Profile Page

Willingness to take PhD Students: Yes

Research Group Members