Page 70 - ebook

[A. Biochemistry/Molecular Biology] A-35

PEX13 is required for thermogenesis of white adipose tissue

in cold-exposed mice

#
Woo Yong Park¹ , Gahee Song¹ , Ja Yeon Park¹ , Jea-Young Um¹,²*
#
#
¹Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul 2447, Korea,
²Department of Pharmacology, College of Korean Medicine, Kyung Hee University, Seoul 2447, Korea

Non-shivering thermogenesis (NST) is a heat generating process controlled by the mitochondria of brown adipose

tissue (BAT). In the recent decade, ‘functionally’ acting brown adipocytes in white adipose tissue (WAT) have been
identified as well: the so-called process of the ‘browning’ of WAT. While the importance of uncoupling protein 1

(UCP1)-oriented mitochondrial activation has been intensely studied, the role of peroxisomes during the browning
of white adipocytes is poorly understood. Here, we assess the change in peroxisomal membrane proteins, or

peroxins (PEXs), during cold stimulation and importantly, the role of PEX13 in the cold-exposed remodeling of white
adipocytes. PEX13, a protein that originally functions as a docking factor and is involved in protein import into

peroxisome matrix, was highly increased during cold-induced recruitment of beige adipocytes within the inguinal
WAT of C57BL/6 mice. Moreover, beige-induced 3T3-L1 adipocytes and stromal vascular fraction (SVF) cells by

exposure to the peroxisome proliferator-activated receptor gamma (PPARγ) agonist rosiglitazone showed a
significant increase in mitochondrial thermogenic factors along with peroxisomal proteins including PEX13, and

these were confirmed in SVF cells with the beta 3 adrenergic receptor (β3AR)-selective agonist CL316,243. To verify
the relevance of PEX13, we used the RNA silencing method targeting the Pex13.