Skip to main content
. Author manuscript; available in PMC: 2018 Apr 4.
Published in final edited form as: Cell Cycle. 2010 Mar 15;9(6):1097–1103. doi: 10.4161/cc.9.6.11046

Figure 1.

Figure 1

Connections between circadian cycles, C/EBPs and the NAD+-Sirt1 pathway may affect G-CSF induced granulopoiesis. The circadian oscillator is composed of transcriptional feedback loops (Red). Clock and Bmal1 drive expression of core clock genes Per, Cry and Rev-Erbα which in turn, inhibit Clock/Bmal1 activity. Throughout the body, these clock cycles are embedded into tissue-specific pathways to sustain local rhythmic physiologies. The Clock/NAD+-Sirt1 feedback loop (brown) couples circadian oscillations to metabolism. Diurnal cytokine patterns link circadian regulation to hematopoietic processes (orange). C/EBP transcription factors may form a feedback loop with the circadian clock (purple) as they regulate core clock genes and are themselves rhythmically expressed in some tissues. In myeloid cells, C/EBPs are part of a feedback loop (green) that regulates granulocyte colony stimulating factor (G-CSF) and G-CSF receptor (G-CSFR) in a NAD+-Sirt1 dependent manner, leading to induction of granulopoiesis.