Short-Term Effect of Rose Bengal Photodynamic Therapy (RB-PDT) on Collagen I, Collagen V, NF-κB, LOX, TGF-ß and IL-6 Expression of Human Corneal Fibroblasts, In Vitro.

PURPOSE: To investigate collagen I, collagen V, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), lysyl oxidase (LOX), transforming growth factor ß1 (TGF-ß1) and interleukin-6 (IL-6) expression in healthy and keratoconus human corneal fibroblasts (HCFs and KC-HCFs), 24 h after Rose Bengal photodynamic therapy (RB-PDT). METHODS: HCFs were isolated from healthy human corneal donors (n = 5) and KC-HCFs from elective penetrating keratoplasties (n = 5). Both cell cultures underwent RB-PDT (0.001% RB concentration, 0.17 J/cm2 fluence) and 24 h later collagen I, collagen V, NF-κB, LOX, TGF-ß1 and IL-6 mRNA and protein expression have been determined using qPCR and Western blot, IL-6 concentration in the cell culture supernatant by ELISA. RESULTS: TGF-ß1 mRNA expression was significantly lower (p = 0.02) and IL-6 mRNA expression was significantly higher in RB-PDT treated HCFs (p = 0.01), than in HCF controls. COL1A1, COL5A1 and TGF-ß1 mRNA expression was significantly lower (p = 0.04; p = 0.02 and p = 0.003) and IL-6 mRNA expression was significantly higher (p = 0.02) in treated KC-HCFs, than in KC-HCF controls. TGF-ß1 protein expression in treated HCFs was significantly higher than in HCF controls (p = 0.04). IL-6 protein concentration in the HCF and KC-HCF culture supernatant after RB-PDT was significantly higher than in controls (p = 0.02; p = 0.01). No other analyzed mRNA and protein expression differed significantly between the RB-PDT treated and untreated groups. CONCLUSIONS: Our study demonstrates that RB-PDT reduces collagen I, collagen V and TGF-ß1 mRNA expression, while increasing IL-6 mRNA and protein expression in KC-HCFs. In HCFs, RB-PDT increases TGF-ß1 and IL-6 protein level after 24 h.

Human corneal epithelial cell and fibroblast migration and growth factor secretion after rose bengal photodynamic therapy (RB-PDT) and the effect of conditioned medium.

PURPOSE: To investigate human corneal epithelial cell and fibroblast migration and growth factor secretion after rose bengal photodynamic therapy (RB-PDT) and the effect of conditioned medium (CM). METHODS: A human corneal epithelial cell line (HCE-T), human corneal fibroblasts (HCF) and keratoconus fibroblasts (KC-HCF) have been used. Twenty-four hours after RB-PDT (0.001% RB concentration, 565 nm wavelength illumination, 0.17 J/cm2 fluence) cell migration rate using scratch assay and growth factor concentrations in the cell culture supernatant using ELISA have been determined. In addition, the effect of CM has been observed. RESULTS: RB-PDT significantly reduced migration rate in all cell types, compared to controls (p≤0.02). Migration rate of HCE-T cultures without RB-PDT (untreated) was significantly higher using HCF CM after RB-PDT, than using HCF CM without RB-PDT (p<0.01). Similarly, untreated HCF displayed a significantly increased migration rate with HCE-T CM after RB-PDT, compared to HCE-T CM without treatment (p<0.01). Furthermore, illumination alone and RB-PDT significantly decreased keratinocyte growth factor (KGF) concentration in HCF and KC-HCF supernatant, and RB-PDT significantly decreased soluble N-Cadherin (SN-Cad) concentration in HCF supernatant, compared to controls (p<0.01 for all). In HCE-T CM, RB-PDT increased hepatocyte growth factor (HGF) and basic fibroblast growth factor (FGFb) concentration (p≤0.02), while decreasing transforming growth factor ß (TGF-ß) concentration (p<0.01). FGFb concentration increased (p<0.0001) and TGF-ß concentration decreased (p<0.0001) in HCF CM, by RB-PDT. Epidermal growth factor (EGF), HGF, and TGF-ß concentration decreased (p≤0.03) and FGFb concentration increased (p<0.01) in KC-HCF CM, using RB-PDT. CONCLUSIONS: HCE-T, HCF and KC-HCF migration rate is reduced 24 hours after RB-PDT. In contrast, HCE-T migration is enhanced using HCF CM after RB-PDT, and HCF migration rate is increased through HCE-T CM following RB-PDT. Modulation of EGF, KGF, HGF, FGFb, TGF-ß and N-Cadherin secretion through RB-PDT may play an important role in corneal wound healing.

UVB phototherapy and skin cancer risk: a review of the literature.

BACKGROUND: UVB phototherapy is a common treatment modality for psoriasis and other skin diseases. Although UVB has been in use for many decades, many clinicians are hesitant to use this type of phototherapy because of concern over increasing the skin cancer risk. Over the past 20 years, numerous studies have been published examining this issue, but a consensus or analysis of the skin cancer risk is required for the dermatologist to make an educated risk-benefit analysis. OBJECTIVE: To assess the risk of skin cancer associated with UVB phototherapy. METHODS: All prospective or retrospective studies were identified in MEDLINE from 1966 to June 2002. Bibliographies were searched to identify any additional studies examining this issue. All studies that attempted to quantify or qualify any additional skin cancer risk from UVB phototherapy were included. Study selection was performed by two independent reviewers. RESULTS: Eleven studies (10 of which concerned psoriasis patients), involving approximately 3400 participants, were included. Of note, three of the studies involved the same cohort: members of the 16-center US Psoralen plus UVA (PUVA) Follow-up Study: Other than the most recent Finnish study, all studies eventually showed no increased skin cancer risk with UVB phototherapy. One of the PUVA cohort studies examined genital skin cancers, and found an increased rate of genital tumors associated with UVB phototherapy, although this study has not been duplicated. CONCLUSION: The evidence suggests that UVB phototherapy remains a very safe treatment modality.