Neuropeptides and Energy Homeostasis

Center of Brain, Behavior and Metabolism 

Group Members

Olaf Jöhren (Group leader)
Sherif Idriss (PhD student)
Landia Lin (PhD student)
Hossna Yassin (MD student)
Christine Eichholz (Technician)

Research Interests

We focus on the transcriptional and translational control of brain pathways involved in the regulation of food intake and the development of diabetes and obesity. In particular, we address orexin receptor expression and signaling as well as the role of astrocytes in brain energy supply. Hypothalamic orexins regulate energy homeostasis, sleep, and the reward system. Currently, we characterize orexin receptor splice variants and their transcriptional regulation, intracellular transport and molecular interactions. In addition, we address the circadian regulation of orexin receptor expression and the transcriptional control of the OX2 receptor promoter. Astrocytes represent a major source for lactate in the brain that may serve as energy substrate for neurons. We study the expression and regulation of hypoxia-inducible factors (HIFs) and their role in the regulation of the glycolytic capacity of astrocytes. Current projects involve the activation of HIFs in astrocytes by neuronal or endothelial factors.

Collaborations

  • Luc Pellerin, Departement de Physiologie, University of Lausanne, Switzerland
  • Harpal Randeva, Metabolic & Vascular Health, University of Warwick Medical School, Coventry, UK

Publications

  1. Nesfatin-1 increases energy expenditure and reduces food intake in rats. Wernecke K, Lamprecht I, Jöhren O, Lehnert H, Schulz C. Obesity (Silver Spring). 2014 Jul;22(7):1662-8.
  2. QRFP induces aldosterone production via PKC and T-type calcium channel-mediated pathways in human adrenocortical cells: evidence for a novel role of GPR103. Ramanjaneya M, Karteris E, Chen J, Rucinski M, Ziolkowska A, Ahmed N, Kagerer S, Jöhren O, Lehnert H, Malendowicz LK, Randeva HS. Am J Physiol Endocrinol Metab. 2013 Nov 1;305(9):E1049-58.
  3. Endothelial cell-derived nitric oxide enhances aerobic glycolysis in astrocytes via HIF-1α-mediated target gene activation. Brix B, Mesters JR, Pellerin L, Jöhren O. J Neurosci. 2012 Jul 11;32(28):9727-35.
  4. Intranasal leptin reduces appetite and induces weight loss in rats with diet-induced obesity (DIO). Schulz C, Paulus K, Jöhren O, Lehnert H. Endocrinology. 2012 Jan;153(1):143-53.
  5. Nitric oxide induces the expression of the monocarboxylate transporter MCT4 in cultured astrocytes by a cGMP-independent transcriptional activation. Marcillac F, Brix B, Repond C, Jöhren O, Pellerin L. Glia. 2011 Dec;59(12):1987-95.