Sebum free fatty acids enhance the innate immune defense of human sebocytes by upregulating beta-defensin-2 expression.
Nakatsuji. Teruaki T; Kao. Mandy C MC; Zhang. Liangfang L; Zouboulis. Christos C CC; Gallo. Richard L RL; Huang. Chun-Ming CM
Key Findings
- Lauric, palmitic, and oleic acids dramatically raise hBD‑2 production in human sebocytes, but not other antimicrobial peptides like LL‑37.
- The hBD‑2 released by treated sebocytes can kill Propionibacterium acnes, and this killing is blocked if hBD‑2 is neutralized.
- Blocking CD36 or NF‑kappaB stops the fatty‑acid‑induced hBD‑2 rise, showing these are required for the effect.
- Topical oleic acid applied to mouse skin also raises the mouse equivalent of hBD‑2, suggesting the finding works in vivo.
Practical Outcomes
- Applying skin‑friendly oils rich in these fatty acids (e.g., coconut oil for lauric acid, olive oil for oleic acid) may enhance your skin's innate defense against acne bacteria by up‑regulating hBD‑2. For biohackers, incorporating such oils into a daily topical regimen could serve as a low‑cost, multi‑functional antimicrobial strategy, especially when combined with other acne‑targeted approaches.
Summary
The study shows that certain skin oils—specifically lauric, palmitic, and oleic acids—can boost the skin's natural antimicrobial peptide hBD‑2 in sebocyte cells. This increase makes the skin better at killing acne‑causing bacteria. The effect works through a cell‑surface transporter (CD36) and the NF‑kappaB signaling pathway.
Abstract
Various sebum free fatty acids (FFAs) have shown antibacterial activity against a broad range of gram-positive bacteria, resulting in the suggestion that they are accountable, at least partially, for the direct antimicrobial activity of the skin surface. In this study, we examined the effects of sebum FFAs on the antimicrobial peptide (AMP)-mediated innate immune defense of human sebocytes. Incubation of lauric acid, palmitic acid, or oleic acid (OA) with human sebocytes dramatically enhanced their expression of human beta-defensin (hBD)-2, one of the predominant AMPs found in the skin, whereas remarkable increases in hBD-1, hBD-3, and human cathelicidin LL-37 were not observed. Secreted hBD-2 was detectable by western blotting in the supernatant of sebocyte culture incubated with each FFA, but not with a vehicle control. The supernatant of FFA-incubated sebocyte culture showed antimicrobial activity against Propionibacterium acnes, whereas the enhanced antimicrobial activity of human sebocytes was neutralized by anti-hBD-2 IgG. In addition, the FFA-induced hBD-2 expression was suppressed by blocking the cluster of differentiation (CD)36 fatty acid translocase on the surface of sebocytes with anti-human CD36 IgG or blocking the NF-kappaB signaling pathway with BMS-345541, a highly selective inhibitor of inhibitory kappaB kinase. These data suggest that sebum FFAs upregulate the expression of hBD-2 in human sebocytes, which may enhance the disinfecting activity of the human sebaceous gland. The FFA-induced upregulation of hBD-2 is facilitated by CD36-mediated FFA uptake and NF-kappaB-mediated transactivation. The upregulation of mouse beta-defensin 4, a mouse ortholog for hBD-2, was also observed in the hair follicle sebaceous glands of mouse ear skin after an epicutaneous application of OA, the most hBD-2-inducible FFA tested. This report highlights the potential of using FFAs as a multifunctional antimicrobial therapy agent for acne vulgaris treatment; FFAs may provide direct antibacterial activities against P. acnes and enhance the skin's innate antibacterial defense by inducing the expression of hBD-2 in sebocytes as well.
Study Information
pubmed
2009
2009-12-24T00:00:00.000Z
10.1038/jid.2009.384
226
57