Shelley Tischkau, PhD

Contact

217.545.6524

stischkau@siumed.edu

Professional Experience

Southern Illinois University School of Medicine, Department of Pharmacology, Springfield IL  2007

Research Interest and Specialties

Dr. Tischkau is a broadly trained neuroendocrinologist, with specific expertise in the design and conduct of studies that examine the function of the circadian timing system at the molecular, physiological and behavioral levels. Her lab has focused on understanding systemic control of circadian rhythms, with particular emphasis on regulation of the master clock in the suprachiasmatic nucleus, its relationship to environmental signals and mechanisms by which circadian timing is conveyed throughout organisms. An understanding of how light affects the master clock allowed the development of environmental paradigms that mimic clock disturbances in real-life scenarios to disrupt the systemic circadian timing system. Circadian clock disruptions are now associated with disease states ranging from metabolic syndrome and cancer to mental health and neurodegenerative disease. Currently, the Tischkau lab focuses on the contributions of the circadian clock to metabolic and brain health. Two major projects are ongoing.

Project 1: Clock regulation of metabolic health through aryl hydrocarbon receptor

The aryl hydrocarbon receptor (AhR) is a PAS-domain containing nuclear receptor. Its similarity to circadian clock components led the Tischkau lab to explore its interactions with the molecular circadian clock. The lab has discovered a complex, reciprocal relationship between AhR signaling and the clock. AhR depletion enhances rhythms and supports metabolic health. Chronic AhR activation suppresses rhythms and promotes obesity and metabolic syndrome. These effects occur subsequent to desynchrony between the central and peripheral circadian systems with AhR acting as a prominent regulator of both circadian and metabolic function in liver and adipose tissues. Ongoing studies use pharmacologic approaches together with genetic manipulation (mouse models) to explore AhR as a target for combating metabolic disease through its interactions with the clock.

Project 2: Clock regulation of neuronal health in aging  

Circadian rhythms are important regulators of sleep and brain health. Circadian disruption alters sleep, but also contributes to neurodegeneration.  This project is focused on mechanisms by which circadian disruption contributes to neuronal demise. The lab has demonstrated that circadian disruption enhances memory impairment in a mouse model of Alzheimer’s disease.  Ongoing studies build on this initial discovery to examine mechanisms by which output from the suprachiasmatic nucleus (SCN) impacts hippocampal function. Alterations in SCN-hippocampal neural circuitry imposed by circadian disruption are explored in normal aging and in Alzheimer’s models using genetically modified mice.