Endocannabinoid tone regulates human sebocyte biology.

We have previously shown that i) endocannabinoids (eCB; e.g. anandamide [AEA]) are involved in the maintenance of homeostatic sebaceous lipid production (SLP) in human sebaceous glands (SG); and ii) eCB treatment dramatically increases SLP. Here, we aimed to investigate the expression of the major eCB synthesizing and degrading enzymes, and to study the effects of eCB uptake inhibitors on human SZ95 sebocytes, thus exploring the role of the putative eCB membrane transporter (EMT), which has been hypothesized to facilitate the cellular uptake and subsequent degradation of eCBs. We found that the major eCB synthesizing (NAPE-PLD, DAGLα and -β) and degrading (FAAH, MAGL) enzymes are expressed in SZ95 sebocytes, and also in SGs (except for DAGLα, whose staining was dubious in histological preparations). Interestingly, eCB uptake-inhibition with VDM11 induced a moderate increase in SLP, and also elevated the levels of various eCBs and related acylethanolamides. Finally, we found that VDM11 was able to interfere with the pro-inflammatory action of the Toll-like receptor 4 activator lipopolysaccharide. Collectively, our data suggest that inhibition of eCB uptake exerts anti-inflammatory actions and elevates both SLP and eCB levels; thus, these inhibitors might be beneficial in cutaneous inflammatory conditions accompanied by dry skin.