will take place on Tuesday, September 24, 2019 from 17:15 to 18:15 hours in CBBM Building, Ground Floor, Seminar Room B1/B2.
Host: Prof. Dr. Henrik Oster
Institute of Neurobiology
University of Lübeck
Abstract
Animal studies have shown the importance of peripheral clocks in the circadian control of metabolism. However, translating this to human chronobiology has been limited by the practical and ethical problems of collecting tissues other than blood. Understanding the circadian regulation of key human metabolic tissues (e.g. adipose and skeletal muscle) has recently come from the development of biopsy approaches conducted within both diurnal and circadian protocols. This work has confirmed that human metabolic tissues exhibit profound 24-hour regulation in key metabolic processes, although there are differences in results between human and animal models.
The relationship between energy intake and circadian physiology is complex. There is daily variation in the physiological response to meals. In the short-term, responses to a given meal vary according to the time at which that meal is eaten. Over a longer-term, timed manipulation of daily energy intake influences body weight, adiposity and insulin sensitivity. In addition to the effect of circadian time on meal responses, there is growing evidence that meal timing is a powerful synchroniser of some human metabolic rhythms. For example, the circadian rhythms of glucose homeostasis and components of the plasma metabolome appear particularly sensitive to mealtime, whereas the circadian rhythm of SCN markers and plasma triglycerides are relatively insensitive to mealtime.
Biosketch
Jonathan Johnston is Reader (Associate Professor) in Chronobiology and Integrative Physiology at the University of Surrey. He has successfully led projects studying links between circadian and metabolic physiology funded by the BBSRC, MRC and Diabetes-UK. His recently published research includes the analysis of: timed meal effects on the human circadian system (Wehrens et al 2017 Current Biology); daily human metabolome rhythms (Isherwood et al 2017 FASEB J); and rhythms in human skeletal muscle (Loizides-Mangoldet al 2017 PNAS; Perrin et al 2018 ELife) and adipose tissue (Christou et al 2019 Sci Rep). He has also published widely on the topic of endocrine rhythmicity. He has a strong track record in public engagement via TV (e.g. BBC2’s Trust Me I’m A Doctor, Channel4’s Food Unwrapped), radio, podcast and written (e.g. The Conversation) media. He has experience working with the food industry, via consultancy work (Kellogg) and research collaboration (Nestlé).
