Format

Send to

Choose Destination
Cell Metab. 2017 Apr 4;25(4):811-822.e4. doi: 10.1016/j.cmet.2017.03.002.

Mitochondrial Patch Clamp of Beige Adipocytes Reveals UCP1-Positive and UCP1-Negative Cells Both Exhibiting Futile Creatine Cycling.

Author information

1
Department of Physiology, University of California, San Francisco, San Francisco, CA 94143, USA.
2
Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
3
Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA.
4
Department of Physiology, University of California, San Francisco, San Francisco, CA 94143, USA. Electronic address: yuriy.kirichok@ucsf.edu.

Abstract

Cold and other environmental factors induce "browning" of white fat depots-development of beige adipocytes with morphological and functional resemblance to brown fat. Similar to brown fat, beige adipocytes are assumed to express mitochondrial uncoupling protein 1 (UCP1) and are thermogenic due to the UCP1-mediated H+ leak across the inner mitochondrial membrane. However, this assumption has never been tested directly. Herein we patch clamped the inner mitochondrial membrane of beige and brown fat to provide a direct comparison of their thermogenic H+ leak (IH). All inguinal beige adipocytes had robust UCP1-dependent IH comparable to brown fat, but it was about three times less sensitive to purine nucleotide inhibition. Strikingly, only ∼15% of epididymal beige adipocytes had IH, while in the rest UCP1-dependent IH was undetectable. Despite the absence of UCP1 in the majority of epididymal beige adipocytes, these cells employ prominent creatine cycling as a UCP1-independent thermogenic mechanism.

PMID:
28380374
PMCID:
PMC5448977
DOI:
10.1016/j.cmet.2017.03.002
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center