Display Settings:

Format

Send to:

Choose Destination
We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
    Proc Natl Acad Sci U S A. 2011 Nov 8;108(45):18560-5. doi: 10.1073/pnas.1115753108. Epub 2011 Oct 31.

    Cell-autonomous circadian clock of hepatocytes drives rhythms in transcription and polyamine synthesis.

    Source

    Section of Cell and Developmental Biology, Division of Biological Sciences, and the Center for Chronobiology, University of California at San Diego, La Jolla, CA 92093-0130, USA.

    Abstract

    The circadian clock generates daily rhythms in mammalian liver processes, such as glucose and lipid homeostasis, xenobiotic metabolism, and regeneration. The mechanisms governing these rhythms are not well understood, particularly the distinct contributions of the cell-autonomous clock and central pacemaker to rhythmic liver physiology. Through microarray expression profiling in Met murine hepatocytes (MMH)-D3, we identified over 1,000 transcripts that exhibit circadian oscillations, demonstrating that the cell-autonomous clock can drive many rhythms, and that MMH-D3 is a valid circadian model system. The genes represented by these circadian transcripts displayed both cophasic and antiphasic organization within a protein-protein interaction network, suggesting the existence of competition for binding sites or partners by genes of disparate transcriptional phases. Multiple pathways displayed enrichment in MMH-D3 circadian transcripts, including the polyamine synthesis module of the glutathione metabolic pathway. The polyamine synthesis module, which is highly associated with cell proliferation and whose products are required for initiation of liver regeneration, includes enzymes whose transcripts exhibit circadian oscillations, such as ornithine decarboxylase and spermidine synthase. Metabolic profiling revealed that the enzymatic product of spermidine synthase, spermidine, cycles as well. Thus, the cell-autonomous hepatocyte clock can drive a significant amount of transcriptional rhythms and orchestrate physiologically relevant modules such as polyamine synthesis.

    PMID:
    22042857
    [PubMed - indexed for MEDLINE]
    PMCID:
    PMC3215069
    Free PMC Article

    Images from this publication.See all images (4)Free text

    Fig. 1.
    Fig. 3.
    Fig. 2.
    Fig. 4.

      Supplemental Content

      Icon for HighWire Icon for PubMed Central

      Save items

      Recent activity

      Your browsing activity is empty.

      Activity recording is turned off.

      Turn recording back on

      See more...
      Write to the Help Desk