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Published on: September 15, 2017
Rose Bengal Photodynamic Therapy (RB-PDT) Modulates the Inflammatory Response in LPS-Stimulated Human Corneal
Ning Chai1,2, Tanja Stachon1, Tim Berger3
1Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Germany.
Purpose:
To investigate the effect of rose bengal photodynamic therapy on lipopolysaccharide-induced inflammation in human corneal fibroblasts. Furthermore, to analyze potential involvement of the mitogen-activated protein kinase and nuclear factor kappa B signaling pathways in this process.
Methods:
Human corneal fibroblast cultures underwent 0-2.0 µg/mL lipopolysaccharide treatment, and 24 h later rose bengal photodynamic therapy (0.001% RB, 565 nm wavelength illumination, 0.17 J/cm2 fluence). Interleukin-6, interleukin-8, intercellular adhesion molecule-1, interferon regulatory factor-3, interferon α2, and interferon β1 gene expressions were determined by quantitative PCR. Interleukin-6, interleukin-8, and C-C motif chemokine ligand-4 concentrations in the cell culture supernatant were measured by enzyme-linked immunosorbent assays and intercellular adhesion molecule-1 protein level in human corneal fibroblasts by western blot. In addition, the nuclear factor kappa B and mitogen-activated protein kinase signaling pathways were investigated by quantitative PCR and phosphorylation of nuclear factor kappa B p65 and p38 mitogen-activated protein kinase by western blot.
Results:
Rose bengal photodynamic therapy in 2.0 µg/mL lipopolysaccharide-stimulated human corneal fibroblasts triggered interleukin-6 and interleukin-8 mRNA (p < .0001) and interleukin-6 protein increase (p < .0001), and downregulated intercellular adhesion molecule-1 expression (p < .001). C-C motif chemokine ligand-4, interferon regulatory factor-3, interferon α2, and interferon β1 expressions remained unchanged (p ≥ .2). Rose bengal photodynamic therapy increased IκB kinase subunit beta, nuclear factor kappa B p65, extracellular signal-regulated kinases-2, c-Jun amino terminal kinase, and p38 transcription (p ≤ .01), and triggered nuclear factor kappa B p65 and p38 mitogen-activated protein kinase phosphorylation (p ≤ .04) in lipopolysaccharide treated human corneal fibroblasts.
Conclusion:
Rose bengal photodynamic therapy of lipopolysaccharide-stimulated human corneal fibroblasts can modify the inflammatory response by inducing interleukin-6 and interleukin-8 expression, and decreasing intercellular adhesion molecule-1 production. C-C motif chemokine ligand-4, interferon regulatory factor-3, and interferon α and β expressions are not affected by rose bengal photodynamic therapy in these cells. The underlying mechanisms may be associated with nuclear factor kappa B and p38 mitogen-activated protein kinase pathway activation.
Insights
Rose bengal photodynamic therapy reduced inflammation in human corneal fibroblasts by decreasing intercellular adhesion molecule-1 and increasing IL-6 and IL-8. This suggests involvement of the NF-κB and p38 MAPK pathways.
Area of Science:
- Ophthalmology
- Cell Biology
- Immunology
Background:
- Inflammation in human corneal fibroblasts can be triggered by lipopolysaccharide (LPS).
- Understanding the molecular pathways involved in LPS-induced inflammation is crucial for developing targeted therapies.
Purpose of the Study:
- To investigate the effects of rose bengal photodynamic therapy (RB-PDT) on LPS-induced inflammation in human corneal fibroblasts.
- To explore the potential involvement of mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways.
Main Methods:
- Human corneal fibroblasts were stimulated with LPS and subsequently treated with RB-PDT.
- Gene and protein expression of inflammatory markers (IL-6, IL-8, ICAM-1) were analyzed using qPCR, ELISA, and Western blot.
- NF-κB and MAPK signaling pathway activation was assessed via qPCR and Western blot analysis of key proteins and their phosphorylation states.
Main Results:
- RB-PDT significantly downregulated intercellular adhesion molecule-1 (ICAM-1) expression in LPS-stimulated fibroblasts.
- RB-PDT increased the mRNA and protein levels of interleukin-6 (IL-6) and interleukin-8 (IL-8).
- Activation of NF-κB and p38 MAPK pathways, including phosphorylation of NF-κB p65 and p38 MAPK, was observed following RB-PDT.
Conclusions:
- RB-PDT modulates the inflammatory response in LPS-treated human corneal fibroblasts by altering IL-6, IL-8, and ICAM-1 levels.
- The findings suggest that NF-κB and p38 MAPK pathways play a role in the mechanism of RB-PDT's anti-inflammatory effects.
- RB-PDT shows potential as a therapeutic strategy for managing corneal inflammation.
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