1. ^*Department of Biochemistry and Molecular Biology, School of Pharmacy, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo, Japan
2. ^†Division of Biochemistry and Molecular Genetics, Department of Molecular and Cellular Biology, Ehime University School of Medicine, Onsen-gun, Ehime, Japan

Correspondence: Takashi Sato, Department of Biochemistry and Molecular Biology, School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan. Email: satotak@ps.toyaku.ac.jp

Received 20 May 2004; Revised 26 November 2004; Accepted 11 January 2005; Published online 3 June 2005.

Abstract

To clarify the involvement of perilipin, a lipid-droplet-surface protein associated with adipocytes and steroidogenic cells, in the differentiation of sebocytes, we investigated the expression of perilipin in sebaceous glands in vivo and in vitro. Perilipin was expressed in sebaceous glands of the hamster auricle in vivo and was localized at the surface of intracellular lipid droplets in differentiated hamster sebocytes in vitro. Western blot analysis showed that perilipin with a molecular weight of approximately 57 kDa, which was identical to that in differentiated mouse 3T3-L1 adipocytes, was detected in cultured sebocytes, indicating that sebaceous glands expressed perilipin A. In addition, the production of perilipin A in cultured sebocytes was transcriptionally augmented by sebocytic–lipogenesis stimulators, insulin, and 5-dihydrotestosterone, whereas it was decreased by a suppressor of sebocytic differentiation, epidermal growth factor. Furthermore, hamster sebocytes were found to express peroxisome proliferation-activating receptor and 1, the activation of which by WY14643 and troglitazone, respectively, caused the transcriptional augmentation of perilipin A expression along with an increase in levels of triacylglycerols in lipid droplets in sebocytes. Therefore, these results provide novel evidence that the expression of perilipin A increases on the surface of intracellular lipid droplets augmented along with the differentiation of hamster sebocytes.