Kalinovich 2015 Abstract MiP2015
|UCP3-related changes in brown and brite/beige adipose tissue in cold-acclimated mice.|
Uncoupling protein 3 (UCP3) is a member of mitochondrial inner membrane carrier family. Earlier we have demonstrated that UCP3 is upregulated in skeletal muscle of the constantly shivering mice that lack the thermogenic protein UCP1. This UCP3 upregulation was correlated with enhanced lipid oxidation . UCP3 is also upregulated in brown adipose tissue (BAT) and inguinal white adipose tissue (ingWAT) during britening/beiging process upon cold acclimation . The function and regulation of UCP3 in brown and brite/beige adipose tissues is unknown.
We acclimated wild-type and UCP3-knockout (UCP3 KO) mice at 4 °C and addressed features of brown and brite/beige adipose tissues: morphology, thermogenic capacity (amount of UCP1 protein by Western blot and respiration of isolated mitochondria), as well as lipid metabolism (expression of genes involved in lipid synthesis and catabolism).
In mice lacking UCP3, both BAT and ingWAT displayed higher total protein content and a morphology with smaller lipid droplets. In BAT, these changes were associated with upregulation of expression levels of several genes involved in lipid droplet formation and lipid composition. In ingWAT, the higher total protein content was correlated with higher number of mitochondria estimated by VDAC content. Neither in BAT nor in ingWAT was thermogenic capacity (UCP1 content) upregulated in the UCP3 KO mice. The thermogenic function of isolated mitochondria did not differ between wild-type and UCP3 KO mice.
Thus, the lack of UCP3 induces changes in lipid metabolism concerning lipid droplet formation in brown adipose tissue. In brite adipose tissue, the lack of UCP3 upregulates mitochondriogenesis.
Labels: MiParea: Respiration, mt-Membrane, nDNA;cell genetics, Genetic knockout;overexpression, Comparative MiP;environmental MiP
Organism: Mouse Tissue;cell: Fat Preparation: Isolated mitochondria
Event: E1 MiP2015
Dept Mol Biosciences, Wenner-Gren Inst, Stockholm Univ, Sweden. - [email protected]
References and acknowledgements
- Shabalina IG, Hoeks J, Kramarova TV, Schrauwen P, Cannon B and Nedergaard J (2010) Cold tolerance of UCP1-ablated mice: a skeletal muscle mitochondria switch toward lipid oxidation with marked UCP3 up-regulation not associated with increased basal, fatty acid- or ROS-induced uncoupling or enhanced GDP effects. Biochim Biophys Acta 1797:968-80.
- Shabalina IG, Petrovic N, de Jong JM, Kalinovich AV, Cannon B and Nedergaard J (2013) UCP1 in brite/beige adipose tissue mitochondria is functionally thermogenic. Cell reports 5:1196-203.