Zusammenfassung
The transcriptional basis of sebocyte differentiation and lipid production is mostly unclear. Peroxisome proliferator-activated receptor gamma (PPAR gamma), a lipid-activated transcription factor, has been implicated in differentiation and lipid metabolism of various cell types. Here, we show that PPAR gamma is differentially expressed in normal and pathological human sebocytes and appears to ...
Zusammenfassung
The transcriptional basis of sebocyte differentiation and lipid production is mostly unclear. Peroxisome proliferator-activated receptor gamma (PPAR gamma), a lipid-activated transcription factor, has been implicated in differentiation and lipid metabolism of various cell types. Here, we show that PPAR gamma is differentially expressed in normal and pathological human sebocytes and appears to have roles in their differentiation and lipid production. We used laser-microdissected normal and pathological human sebaceous glands (SGs) and SZ95 cells (immortalized sebocyte cell line) analyzed by real-time quantitative PCR and immunohistochemistry. Lipids were analyzed by quantitative fluorimetry-and mass spectrometry-based approaches. We have observed that PPAR gamma and its target genes, ADRP (adipose differentiation-related protein) and PGAR (PPAR gamma angiopoietin-related protein), are expressed in sebocytes and show association with their level of differentiation. Also, PPAR gamma is present in normal and hyperplastic SG, whereas its expression levels are decreased in SG adenoma and SG carcinoma cells, reflecting a maturation-linked expression pattern. Furthermore, in SZ95 sebocytes, naturally occurring lipids, including arachidonic acid and arachidonic acid keto-metabolites (e. g., 5-KETE (5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid), 12-KETE (12-oxo-5Z,8Z,10E,14Z-eicosatetraenoic acid)), appear to regulate PPAR gamma signaling pathways, which in turn modulate phospholipid biosynthesis and induce neutral lipid synthesis. Collectively, our findings highlight the importance of endogenous ligand-activated PPAR gamma signaling in human sebocyte biology and suggest that PPAR gamma might be a promising candidate for the clinical management of SG disorders.