The antimicrobial peptide LL-37 is anti-inflammatory and proapoptotic in human periodontal ligament cells.
Jönsson. D D; Nilsson. B-O BO
Key Findings
- Low‑dose LL‑37 (0.1‑1 µM) blocks inflammation signals caused by bacterial components in periodontal ligament cells
- High‑dose LL‑37 (8 µM) sharply cuts DNA synthesis and triggers cell death (apoptosis) in these cells
Practical Outcomes
- If you’re looking at LL‑37 for oral health, low concentrations might help reduce gum inflammation, but higher amounts could damage gum tissue. Until human trials are done, it’s safest to avoid self‑administering LL‑37, especially at doses that approach the cytotoxic range observed in the lab.
Summary
LL-37, a natural antimicrobial peptide, can calm down inflammation in gum‑related cells at low doses, but if you use a lot it kills those cells and stops them from dividing. The study was done in a lab dish, not in people, so the results are early and need more testing before any real‑world use.
Abstract
The antimicrobial peptide LL-37 is expressed in periodontal tissue, and variations in LL-37 levels have been associated with periodontal disease. The effects of LL-37 on periodontal ligament cell function have not been described before. Here, we assess anti-inflammatory properties of LL-37 and investigate the effects of LL-37 on cell differentiation, cell proliferation and apoptosis in human periodontal ligament cells. Periodontal ligament cells were obtained from teeth extracted for orthodontic reasons. Cytokine (interleukin-6) and chemokine (monocyte chemoattractant protein-1) expression was determined by quantitative PCR, cell differentiation by alkaline phosphatase activity, cell proliferation by counting cells in a Bürker chamber, DNA synthesis by incorporation of radiolabeled thymidine and apoptosis by cell morphology and activated caspase 3 quantities. Treatment with 0.1 and 1 μm of LL-37 totally reversed lipopolysaccharide-induced monocyte chemoattractant protein-1 expression and suppressed lipopolysaccharide-induced interleukin-6 expression by 50-70%. LL-37 had no effect on alkaline phosphatase activity. Incubation with 8 μm LL-37 strongly reduced cell number. DNA synthesis was attenuated by about 90% in response to 8 μm LL-37, confirming its antiproliferative effect. Cell morphology was altered in an apoptosis-like fashion in cells treated with 8 μm LL-37. Furthermore, the quantity of activated caspase 3 was increased in cells treated with 1 and 8 μm of LL-37, suggesting apoptosis. LL-37 strongly attenuates lipopolysaccharide-induced cytokine and chemokine expression and, in high concentrations, reduces cell proliferation through inhibition of DNA synthesis and by promoting apoptosis in human periodontal ligament cells.
Study Information
pubmed
2011
2011-11-09T00:00:00.000Z
10.1111/j.1600-0765.2011.01436.x
39
35