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During replication, bypass of DNA lesions is orchestrated by the Rad6 pathway. Monoubiquitination of proliferating cell nuclear antigen (PCNA) by Rad6/Rad18 leads to recruitment of translesion polymerases for direct and potentially mutagenic damage bypass. An error-free bypass pathway may be initiated via K63-linked PCNA polyubiquitination by Ubc13/Mms2 and the E3 ligase Rad5 in yeast, or HLTF/SHPRH in vertebrates. For the latter two enzymes, redundancy with a third E3 ligase and alternative functions have been reported. We have previously shown that the Rad6 pathway is involved in somatic hypermutation of immunoglobulin genes in B lymphocytes. Here, we have used knockout strategies targeting expression of the entire SHPRH protein or functionally significant domains in chicken DT40 cells that do not harbor a HLTF ortholog. We show that SHPRH is apparently redundant with another E3 ligase during DNA damage-induced PCNA modification. SHPRH plays no substantial role in cellular resistance to drugs initiating excision repair and the Rad6 pathway, but is important in survival of topoisomerase II inhibitor treatment. Removal of only the C-terminal RING domain does not interfere with this SHPRH function. SHPRH inactivation does not substantially impact on the overall efficacy of Ig diversification. Redundancy of E3 ligases in the Rad6 pathway may be linked to its different functions in genome maintenance and genetic plasticity., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Immunoglobulin (Ig) diversification by somatic hypermutation in germinal center B cells is instrumental for maturation of the humoral immune response, but also bears the risk of excessive or aberrant genetic changes. Thus, introduction of DNA damage by activation-induced cytidine deaminase as well as DNA repair by multiple pathways need to be tightly regulated during the germinal center response to prevent lymphomagenesis. In the present study, we show that DNA damage checkpoint signaling via checkpoint kinase 1 (Chk1) negatively regulates somatic hypermutation. Chk1 inhibition in human B cell lymphoma lines as well as inactivation of Chk1 alleles by gene targeting in DT40 B cells leads to increased somatic hypermutation. This is apparently due to changes in DNA repair pathways regulated by Chk1, such as a decreased homologous recombination efficiency that also leads to decreased Ig gene conversion in DT40. Our data show that Chk1 signaling plays a crucial role in regulation of Ig diversification and sheds unexpected light on potential origins of aberrant somatic hypermutation in B cell lymphomagenesis.

Maintenance of genome integrity relies on multiple DNA repair pathways as well as on checkpoint regulation. Activation of the checkpoint kinases Chk1 and Chk2 by DNA damage triggers cell cycle arrest and improved DNA repair, or apoptosis in case of excessive damage. Chk1 and Chk2 have been reported to act in a complementary or redundant fashion, depending on the physiological context. During secondary immunoglobulin (Ig) diversification in B lymphocytes, DNA damage is abundantly introduced by activation-induced cytidine deaminase (AID) and processed to mutations in a locus-specific manner by several error-prone DNA repair pathways. We have previously shown that Chk1 negatively regulates Ig somatic hypermutation by promoting error-free homologous recombination and Ig gene conversion. We now report that Chk2 shows opposite effects to Chk1 in the regulation of these processes. Chk2 inactivation in B cells leads to decreased Ig hypermutation and Ig class switching, and increased Ig gene conversion activity. This is linked to defects in non-homologous end joining and increased Chk1 activation upon interference with Chk2 function. Intriguingly, in the context of physiological introduction of substantial DNA damage into the genome during Ig diversification, the 2 checkpoint kinases thus function in an opposing manner, rather than redundantly or cooperatively.

Background: Previous work has indicated that extracorporeal photochemotherapy (ECP) may be a safe and effective treatment in patients with severe atopic dermatitis., Methods: We performed a prospective study to investigate the effect of a defined 20-week ECP protocol in patients with severe, refractory atopic dermatitis. The patient inclusion criteria included (i) disease duration of at least 1 year, (ii) SCORAD > 45, and (iii) resistance to first-line therapy, including topical steroids, topical calcineurin inhibitors, and one form of phototherapy (UVA, UVB, or PUVA) or one second-line therapy, including systemic steroids or cyclosporine. Ten patients (4 women and 6 men; age range 29 to 61 years) were enrolled and treated with two sessions of standard ECP in 2-week intervals for 12 weeks and 4-week intervals thereafter until week 20. The patients' clinical status and response was determined by SCORAD at baseline and every 2 weeks, and quality of life was assessed every 4 weeks using SKINDEX, SF-36, and FACT scores., Results: There was a statistically significant (p = 0.015) reduction of the mean SCORAD by 10.3 (95% CI, 2.5 to 18.0) from 64.8 at baseline to 54.5 (i.e., 15.9% reduction) at week 20. In a subset of patients (all of female sex), the relative reduction in SCORAD after ECP was more than 25% at week 20. Improvement in quality of life measured by SKINDEX, SF-36, and FACT did not reach statistical significance., Conclusions: We detected a small but significant therapeutic effect of ECP in patients with severe, refractory atopic dermatitis.

In contrast to lower eukaryotes, most vertebrate cells are characterized by a moderate efficiency of homologous recombination (HR) and limited feasibility of targeted genetic modifications. As a notable exception, the chicken DT40 B cell line is distinguished by efficient homology-mediated repair of DNA lesions during Ig gene conversion, and also shows exceptionally high gene-targeting efficiencies. The molecular basis of these phenomena is elusive. Here we show that the activity levels of Ubc13, the E2 enzyme responsible for non-canonical K63-linked polyubiquitination, are critical for high efficiency of Ig gene conversion and gene targeting in DT40. Ubc13(+/-) cells show substantially lower homology-mediated repair, yet do not display changes in somatic hypermutation, overall DNA repair or cell proliferation. Our results suggest that modulation of the activity of K63-linked polyubiquitination may be used to customize HR efficiencies in vertebrate cells.

Background: Ultraviolet (UV) A1 and narrowband (NB)-UVB have been reported to be effective treatments for atopic eczema (AE)., Objectives: We aimed to compare the efficacy of medium-dose UVA1 and NB-UVB mono-phototherapy in patients with AE., Methods: A randomized double-blind controlled crossover trial (ClinicalTrials.gov Identifier: NCT00419406) was conducted in which patients with AE received a 6-week course of both medium-dose UVA1 and NB-UVB. Clinical efficacy was assessed using the Six Area, Six Sign, Atopic Dermatitis (SASSAD) score and a visual analogue scale for pruritus. Assessment of health-related quality of life was performed using the Skindex-29. Total immunoglobulin E (IgE) and eosinophilic cationic protein (ECP) were evaluated at baseline and after each phototherapy course., Results: Twenty-eight patients who completed both UVA1 and NB-UVB phototherapy courses on an intention-to-treat basis were analysed according to the crossover design. Both interventions were associated with significant clinical improvement but there was no significant difference between treatments with respect to the mean +/- SD relative reduction (RR) of the clinical scores (SASSAD, 43.7 +/- 31.4% vs. 39.4 +/- 24.1%, P = 0.5; pruritus score, 16 +/- 61.8% vs. 25.2 +/- 30.5%, P = 0.5, respectively). There was no significant difference in the mean +/- SD RR of the Skindex-29 after UVA1 and NB-UVB phototherapy (12.7 +/- 18.8% vs. 16.5 +/- 17.6%, P = 0.1). Changes in the total IgE and ECP levels following UVA1 and NB-UVB did not differ significantly (P = 0.3 and P = 0.9, respectively)., Conclusions: A 6-week course of NB-UVB and UVA1 phototherapy of AE resulted in significant clinical improvement. With regard to efficacy and tolerability, both phototherapeutic modalities may be considered comparably good.

Background: There is a lack of data with regard to the interaction between ultraviolet (UV) radiation and topical calcineurin inhibitors., Objective: We aimed to investigate (1) the UV transmission through tacrolimus ointment and (2) the impact of topical exposure to tacrolimus on the protein expression of thymine dimers (TD) and p53 in human skin., Methods: Spectrophotometric measurements (290-400 nm) of tacrolimus ointment and the vehicle were performed. Eight subjects were treated with tacrolimus ointment and the vehicle thrice daily over a 3-day period on the back. Pre-treated sites and one control site were exposed to two minimal erythema doses UVB. Skin biopsies were taken 1h and 24h after irradiation. Immunohistochemical procedures were used for the detection of TD and p53., Results: Mean UV transmission was over 94% and did not significantly differ between tacrolimus ointment and the vehicle. Immunohistological examinations of TD and p53 expression did not demonstrate significant differences between irradiated sites, irradiated plus vehicle treated sites, and irradiated plus tacrolimus treated sites both 1h and 24h post-irradiation., Conclusions: The present data suggest that tacrolimus ointment hardly has UV blocking capacities and does not significantly interfere with development and/or removal of local DNA damage in human skin.

Background: Atopic eczema (AE) is a common pruritic and chronically relapsing inflammatory skin disease in which cytokines seem to represent important factors in the pathogenesis., Objectives: We aimed to investigate cytokine mRNA expression in the skin of patients with AE who underwent a course of ultraviolet A1 (UVA1) phototherapy., Methods: We studied 21 patients diagnosed with extrinsic AE who were treated with a 6-week course of UVA1 phototherapy. Skin biopsies were taken from healthy controls (n=18) and patients with AE at baseline and after the last UVA1 exposure. Quantitative real-time reverse transcriptase-polymerase chain reaction was performed for interleukin (IL)-4, IL-5, IL-10, IL-13 and IL-31., Results: A significant reduction of the clinical scores was observed after treatment with UVA1. Except for IL-4, cytokine mRNA expression was significantly increased prior to phototherapy when compared with controls. mRNA levels of IL-4 and IL-10 before UVA1 did not significantly differ from levels observed after UVA1. However, a significant decrease of IL-5, IL-13 and IL-31 mRNA expression was observed following UVA1 treatment. IL-31 mRNA levels were even adjusted to the levels of healthy controls., Conclusions: We have shown that the resolution of extrinsic AE lesions following phototherapy is accompanied by significant reduction of mRNA expression of IL-5, IL-13 and IL-31, supporting current concepts that these cytokines play a crucial role in the pathogenesis of extrinsic AE and possibly represent targets for phototherapy.

Background: Patients with atopic dermatitis (AD) are prone to have skin infections. We aimed to investigate mRNA expression levels of various antimicrobial peptides and proteins (AMPs) in AD patients, and compare it with psoriasis vulgaris (PV) patients and healthy subjects., Methods: Skin biopsies were obtained from healthy subjects and patients with AD and PV. Quantitative real-time RT-PCR was used to determine the mRNA levels of human beta-defensin (hBD)-1, hBD-2, hBD-3, LL-37, psoriasin, RNase 7, interferon-gamma, and interleukin-10 (IL-10)., Results: Except for LL-37, mRNA of hBDs, psoriasin, and RNase 7 was significantly higher expressed in AD (n = 42) and/or PV (n = 35) patients when compared to controls (n = 18). While PV lesions showed significantly higher mRNA hBD-2 levels than lesions of AD, the latter was associated with significantly higher mRNA levels of RNase 7 when compared to PV. A significant positive correlation of hBD expression was observed both in AD patients and PV patients. hBD mRNA levels of AD skin correlated with psoriasin and RNase 7 levels. hBD-1 mRNA expression correlated with AD activity and IL-10 mRNA expression., Conclusions: Most AMPs investigated in this study proved to be overexpressed in AD as well as PV when compared to controls. However, a statistically significant difference in AMP mRNA expression between AD and PV was only found for hBD-2 and RNase 7. A moderate-to-strong linear relationship between the mRNA expression of particular AMPs appears to exist in AD, and to a lesser extent in PV as well., (Copyright 2008 S. Karger AG, Basel.)

Pityriacitrin (PIT), produced by Malassezia yeasts, is an UV absorbing substance that might cause hypopigmentation in pityriasis versicolor alba. We aimed to investigate the UV protective effect of PIT in humans using in vitro and in vivo test methods. Spectrophotometry of PIT cream and the vehicle was performed in the wavelength range from 290 to 400 nm. UV transmission and the sun protection factor (SPF) were assessed for different cream formulations. Using colorimetry we evaluated erythema and pigmentation following irradiation of cream-protected and non-protected skin of healthy subjects. UVB as well as UVA transmission decreased with increasing PIT concentrations. An increase of PIT concentration of 1.25, 2.5, and 5% was associated with slightly increasing SPFs of 1.4, 1.5, and 1.7, respectively. Our in vivo tests confirmed the validity of the SPF of PIT 5% cream determined in vitro. In conclusion, the UV protective effect of PIT is all in all very weak suggesting that PIT is likely only an inferior cofactor in the development of hypopigmentation in pityriasis versicolor alba lesions following sun exposure.

Background: Basal cell carcinoma (BCC) is the most common cancer in humans placing a significant burden on healthcare services worldwide. There is an increasing evidence that the development of cutaneous epithelial tumours is pathogenetically linked to dysregulations of the transforming growth factor beta (TGF-beta) and its signalling molecules, the Smads., Objective: In the present study we aimed to investigate the mRNA as well as protein expression of TGF-beta/ Smad signalling proteins in patients with BCC and healthy controls., Methods: In this prospective pilot study, 24 patients with BCC were recruited. Punch biopsies were harvested from the centre of the tumour (lesional) as well as an adjacent healthy skin site (non-lesional controls). In addition to the specimens of BCC patients, skin samples (healthy controls) were obtained from subjects who had no history of skin cancer (n = 25). Real-time RT-PCR as well as immunohistochemistry was performed. -, Results: The mRNA levels of TGF-b/Smad transducers observed in healthy controls did not significantly differ from TGF-beta/Smad levels observed in non-lesional skin of BCCs patients (P > 0.05). RT-PCR revealed significant mRNA overexpression of TGF-beta1, Smad3, and Smad7 in BCCs as compared to non-lesional skin (P < 0.05). TGF-beta1 mRNA expression significantly correlated with Smad3 (r = 0.60; P < 0.05) and Smad7 (r = 0.76; P < 0.05) levels. Immunohistochemistry demonstrated marked protein overexpression of Smad3 in tumour tissue as compared to non-lesional skin., Conclusions: Our data suggest a possible role of TGF-beta/Smad signalling in the pathogenesis of BCC.

Background: Liposuction-curettage (LC) is an effective surgical therapy option for axillary hyperhidrosis, with less scarring compared with radical excision of axillary skin. Although this method has proven to be effective, the treatment of nonresponders to minimally invasive surgery has not been previously defined. Whether these patients benefit from a second surgical procedure has not been evaluated so far., Objectives: To investigate efficacy and side-effects of a second LC with an aggressive rasping cannula in patients with insufficient prior surgery., Methods: Nineteen nonresponders to prior LC (13 female and six male) underwent a second LC with a rasping cannula. Gravimetry was performed before and 8 months after surgery. Side-effects, patient satisfaction, the surgeons' intraoperative evaluation and the Vancouver Scar Scale (VSS) before and after surgery were documented., Results: Sweat rates showed a reduction of 69% in 17 (89%) patients. Two patients (11%) did not respond to surgery. Eighty-four per cent of all patients were completely satisfied or satisfied with postoperative results. No severe side-effects were observed. The surgeon reported slightly increased difficulties during dissection of dermis from subcutaneous fat in three patients. Assessment of scars showed an excellent aesthetic outcome (mean VSS 0.79 before vs. 1.1 after surgery)., Conclusions: LC using an aggressive cannula is an effective therapy option for patients with insufficient response to prior LC surgery, with a low risk of side-effects.

The human beta-defensins (hBDs) are peptides with a strong antimicrobial activity. Patients with atopic dermatitis (AD) and mycosis fungoides (MF) are prone to skin infections. We aimed to investigate the mRNA expression of hBDs in lesional and non-lesional skin of MF patients, and to compare the data with hBD levels found in AD patients and healthy controls. In this prospective pilot study, 13 patients with MF were recruited. Punch biopsies were harvested from the centre of the tumour (lesional) as well as a healthy skin site (non-lesional controls). In addition to the specimens of MF patients, skin samples (healthy controls) were obtained from healthy subjects (n = 15) and patients with acute AD (n = 14). In order to detect mRNA of hBDs, we performed quantitative real-time reverse transcriptase polymerase chain reaction. As compared to healthy controls, skin of patients with MF (non-lesional and lesional) and AD patients showed significantly lower hBD-1 mRNA expression and significantly higher hBD-2 and hBD-3 mRNA expression. HBD-1 mRNA levels of lesional skin were significantly lower than those of non-lesional skin. By contrast, significantly increased hBD-2 and hBD-3 mRNA expression was found in lesional skin of MF patients when compared to non-lesional skin. HBD mRNA expression in lesional skin of MF patients did not significantly differ from hBD expression that was observed in AD lesions. We observed an identical pattern of hBD expression in MD and AD suggesting a common regulatory mechanism that might mainly be driven by T helper 2 lymphocytes.

Patients with localized scleroderma underwent an 8-week course of ultraviolet A1 phototherapy. At baseline, decorin levels of lesional skin were significantly lower than those of nonlesional skin and healthy control subjects. After ultraviolet A1 phototherapy, decorin levels of lesional skin were significantly higher than baseline. Decorin may be of significance in the pathogenesis of localized scleroderma.

Background: Approximately 75-95% of patients with cutaneous lupus erythematosus respond to antimalarial therapy and/or topical glucocorticosteroids. Immunosuppressive agents are usually considered a second-line approach in patients with resistant disease., Objectives: This was a prospective, nonrandomized, open pilot study to evaluate the efficacy of mycophenolate sodium monotherapy in patients with recalcitrant subacute cutaneous lupus erythematosus (SCLE)., Methods: Monotherapy with oral enteric-coated mycophenolate sodium 1440 mg daily was given for a total of 3 months. Treatment outcome was evaluated by means of a validated clinical score for cutaneous lupus erythematosus, the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI), as well as 20-MHz ultrasound measurements and colorimetry. Safety assessment included the monitoring of adverse effects and clinical laboratory parameters., Results: Ten patients with active SCLE resistant to at least one standard therapy were included in the trial. Mycophenolate sodium led to a remarkable improvement of skin lesions, resulting in a significant decrease of the mean +/- SD CLASI from 10.8 +/- 6.0 at the beginning to 2.9 +/- 2.6 at the end of therapy. Clinical improvement was confirmed by ultrasonographic assessments and colorimetry. No serious side-effects were noted., Conclusions: Mycophenolate sodium is beneficial and safe in the treatment of patients with SCLE that failed standard therapy. However, these preliminary data must be confirmed by randomized controlled trials including a larger sample size.

Background: Despite the significant role of the transforming growth factor (TGF)-beta/Smad pathway in cell growth and extracellular matrix regulation, relatively little is known regarding the effect of ultraviolet (UV) radiation on the TGF-beta/Smad signalling in human skin., Objectives: We aimed to investigate the impact of UVA1 and UVB on the mRNA and protein expression of TGF-beta/Smad signal transducers in human skin in vivo., Methods: Fifteen subjects were exposed to 1.5 minimal erythema doses (MED) (4.5 MED cumulative) of UVA1 and UVB over a 3-day period. Skin biopsies were obtained at 24 and 72 h after the last UV exposure. Real-time reverse transcription-polymerase chain reaction and immunohistology were performed., Results: In the UVA1-exposed sites (24 h, 72 h), mRNA expression of TGF-beta1 and Smad3/4/7 was significantly downregulated as compared with nonirradiated skin sites (P < 0.05). At 24 h, immunohistology revealed significantly reduced TGF-beta1 protein levels in fibroblasts (P < 0.05). However, mRNA and protein expression of TGF-beta/Smad proteins observed in UVB-irradiated sites did not differ significantly from control sites (P > 0.05)., Conclusions: In contrast to UVB, UVA1 significantly downregulates the expression of TGF-beta/Smad proteins in human skin in vivo. The extent to which the acute effects of TGF-beta/Smad signalling reported in the present paper are related to the beneficial effect of UVA1-based phototherapy of fibrotic skin conditions and/or to the chronic effects of UV that result in photoaging and cancer remains to be established.

Introduction: Atopic dermatitis (AD) is a complex disease with a variety of possible treatment regimens. The study objective was to demonstrate that methoxsalen used in conjunction with the Uvar XTS photopheresis system (Therakos, Exton, Pa., USA) is safe and can have a clinical effect on the skin manifestations and the quality of life in patients with severe, refractory AD., Methods: Single-arm, open-label treatment using the Uvar XTS photopheresis system. Seven patients (4 male and 3 female, median age: 47 years) with severe (SCORAD >45) AD of at least 12 months duration who in the preceding 12 months had been refractory to all 3 of the first-line therapies for AD, i.e. topical steroids, topical calcineurin inhibitors and one form of phototherapy (UVA, UVB or PUVA), or to one of the second-line therapies like systemic steroids or cyclosporine were included in the study. Treatment consisted of two extracorporeal photopheresis treatments (ExP) on successive days every 2 weeks for a minimum of 12 weeks to a maximum of 20 weeks. Quality of life assessment was performed with the SF-36 Health Survey and the Functional Assessment of Chronic Illness Therapy FACT-G Survey. Clinical improvement was documented with SCORAD assessment., Results: ExP led to a significant decrease in the SCORAD score from 77.7 after 10 cycles to 55.6. Patients reported that they had begun to notice improvement of their skin conditions after 5 cycles of photopheresis. The FACT-G score showed significant improvement from 64.8 to 72.9 (p < 0.05) and the SF-36 Health Survey showed significant improvement in the emotional well-being subscores (p < 0.05)., Conclusions: ExP can have a significant therapeutic effect on the skin and quality of life improvement in a selected group of patients with severe AD who are refractory to conventional forms of therapy. However, larger studies are needed to further evaluate its therapeutic potential., (Copyright (c) 2007 S. Karger AG, Basel.)

Diagnosis of cutaneous forms of lupus erythematosus (LE), including chronic discoid LE (CDLE) and subacute cutaneous LE (SCLE), is usually based on characteristic clinical and histopathological findings. We aimed to visualize morphological changes in lesions of cutaneous LE using optical coherence tomography (OCT), and to correlate the OCT findings with histopathology. Six patients with CDLE and five patients with SCLE were investigated. Prior to skin biopsy, OCT assessment was performed on previously marked lesions. The images of OCT and corresponding histology were evaluated side-by-side on the PC screen. The thickening and disruption of the entrance signal in OCT images correlated with the hyperkeratosis which was observed in the histological sections. Atrophy of the epidermis, which was demonstrated by histology, could also be detected in the OCT pictures showing a thinned layer below the entrance signals. On OCT, a patchy reduction of reflectivity was observed in the upper dermis corresponding to dense patchy, partly lichenoid, lymphocytic infiltrates and oedema of the upper dermis. Furthermore, OCT images displayed increased signal-free cavities which histopathologically corresponded to dilated vessels in the upper dermis. All OCT parameters studied significantly (P < 0.05) correlated with histopathological features as indicated by coefficients of correlation ranging from 0.55 to 0.94. OCT enables to demonstrate micromorphological changes in cutaneous LE which correlate with histopathological findings. Nevertheless, the current technique does not allow one to visualize definite diagnostic features of cutaneous LE. However, OCT may be a promising method for objective monitoring of LE activity and treatment effects over time in vivo.

Background: The epidermal expression of antimicrobial peptides (AMPs) such as human beta-defensin (hBD)-2 and cathelicidin LL-37 is downregulated in atopic eczema (AE) as compared with psoriasis. Hence, AMPs may represent important cofactors in the pathogenesis of AE., Objectives: In the present pilot study we aimed to investigate whether the cutaneous mRNA expression of AMPs is altered in patients with AE following narrowband ultraviolet B (NB-UVB) phototherapy., Methods: We studied 12 patients diagnosed with extrinsic AE who underwent a 6-week course of NB-UVB. Skin biopsies were taken from healthy controls (n = 12) and patients with AE at baseline and after the last NB-UVB irradiation. Quantitative real-time reverse transcription-polymerase chain reaction was performed for hBD-1, hBD-2, hBD-3 and LL-37., Results: A significant (P < 0.05) reduction in the clinical score was observed after treatment with NB-UVB. As compared with controls, patients with AE showed a significantly lower hBD-1 mRNA expression and significantly higher hBD-2 levels (P < 0.05). Following NB-UVB treatment of patients with AE we observed a significant increase of hBD-1 expression as well a significant decrease of hBD-2 (P < 0.05). Levels of hBD-3 and LL-37 did not significantly differ between the groups (P > 0.05)., Conclusions: The pattern of mRNA expression of constitutive (hBD-1) as well as inducible (hBD-2) AMPs seems to be altered in AE as compared with healthy controls. The resolution of AE lesions following phototherapy is accompanied by significant changes in mRNA expression of hBDs, indicating that AMPs may play a role in the pathogenesis of AE.

Localized scleroderma (LS) is a connective skin disease with marked sclerosis of the skin as the most prominent feature. Transforming growth factor beta (TGF-beta) plays a central role in the pathogenesis of sclerotic skin diseases. Recently, special attention was contributed to a family of transcription factor proteins involved in TGF-beta signal transduction from cell surface to the nucleus, the so-called SMADs. Ultraviolet (UV) irradiation has been reported to alter TGF-beta/SMAD pathway in human skin. We sought to investigate the effects of UVA1 on the gene and protein expressions of the TGF-beta/SMAD pathway in LS. UVA1 phototherapy was performed in eight LS patients five times weekly for 8 weeks resulting in a total of 40 treatment sessions (single dose 50 J/cm(2), cumulative dose 2,000 J/cm(2)). TGF-beta1, SMAD3, SMAD4, and SMAD7 mRNA expressions were determined by semiquantitative real-time reverse transcription polymerase chain reaction in lesional and unaffected skin of patients with LS. Additionally, immunohistochemical staining was performed in lesional skin before and after irradiation. Skin status markedly improved in all patients, resulting in a significant reduction of the clinical score from baseline to the end of treatment. Inhibitory SMAD7 mRNA was significantly higher in lesional skin as compared to unaffected skin, and significantly decreased after UVA1 phototherapy. In contrast, SMAD7 mRNA levels remained unchanged in irradiated, healthy skin after UVA1. Both TGF-beta and SMAD3 mRNA levels decreased after UVA1, whereas SMAD4 mRNA increased. However, changes in TGF-beta, SMAD3, and SMAD4 mRNA after UVA1 did not reach statistical significance. Immunohistochemical investigation did not reveal significant changes in the protein expression of SMADs after UVA1. Similar to scleroderma, SMAD7-mediated negative regulation seems to be impaired in LS. UVA1 phototherapy demonstrated the alteration of SMAD7 gene expression in LS, as SMAD7 mRNA levels normalized after UVA1. The pathogenetic relevance of SMAD7 levels with respect to clinical improvement needs further investigation.

A dose- and vehicle-controlled study on the pretreatment and posttreatment effect of 0.1% tacrolimus ointment on erythema induced by solar-simulated ultraviolet (UV) radiation was performed. Surprisingly, comparisons of clinical erythema scores and colorimetric data obtained 24 and 72 hours after UV exposure did not reveal significant differences between the control, tacrolimus, and vehicle preirradiation and postirradiation treated sites (P > .05). Our data strongly indicate that topical tacrolimus neither prevents nor abolishes UV-induced erythema in a clinical meaningful degree.

There is evidence that cytokines (CKs) play a significant role in the development and/or progression of skin cancer. The aim of the present study was to investigate the mRNA expression of tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and IL-8 in biopsy specimens of basal cell carcinoma (BCC), and to compare the results with the mRNA levels of non-lesional skin of BCC patients and healthy subjects. Skin samples were obtained from 22 patients with BCC (lesional, non-lesional) and 25 healthy subjects (controls). Routine histology and real-time RT-PCR was performed. Histological examination revealed 12 nodular BCCs and 10 superficial BCCs. The mRNA levels of CKs observed in healthy controls did not significantly (P > 0.05) differ from non-lesional CK levels of BCCs patients. However, IL-6 and IL-8 levels of lesional skin were significantly (P < 0.05) higher than the CK levels observed in non-lesional skin and controls, respectively. mRNA expression of IL-6 and IL-8 showed a significant positive correlation (r = 0.51; P < 0.05). There was no significant (P > 0.05) difference between lesional mRNA levels of TNF-alpha and those levels observed in non-lesional skin and controls. The mRNA expression of CKs found in nodular and superficial BCCs did not significantly differ (P > 0.05). BCC is associated with a significant increase of IL-6 and IL-8 expression. We have shown for the first time that upregulation of IL-6 mRNA significantly correlates with IL-8 overexpresssion. In accordance with previous studies our data suggest a role for IL-6 and IL-8 in the development and/or progression of BCC, since mRNA expression of both CKs are significantly increased in tumour tissue.

The effects of acute and chronic ultraviolet (UV) on the morphology of human skin have been extensively studied ex vivo by means of histological investigations. However, innovative skin imaging techniques enable visualization of micromorphological structures in vivo. We aimed to perform a correlation study evaluating in vivo dose and time dependent skin changes following solar-simulated irradiation using noninvasive techniques such as optical coherence tomography (OCT) and confocal laser scanning microscopy (CLSM). The forearms of 10 healthy subjects were exposed to 1 minimal erythema dose (MED) and 3 MED of solar-simulated radiation. Noninvasive measurements were performed before and 24 h and 72 h after UV exposures. We demonstrate definite OCT and CLSM findings obtained from UV-exposed skin, including an increase in epidermal thickness (hyperproliferation, acanthosis), a reduction in dermal reflectivity (dermal edema), an increase in brightness of the basal layer (pigmentation), and an increase in vessel diameter within the dermal papillae (vasodilatation). A moderate to strong linear association between the methods employed was observed. In conclusion, noninvasive high-resolution imaging techniques such as OCT and CLSM may be promising tools for photobiological studies aimed at assessing photoadaptive and/or phototoxic processes in vivo. However, larger studies are needed to demonstrate the applicability of the findings presented in this pilot study.

Diagnostic phototesting, including the determination of the minimal erythema dose (MED), is a useful procedure to detect abnormal sensitivity to UV radiation. We aimed to estimate the reference limits (RLs) of the MED in a reasonably large reference sample of white individuals. Skin phototypes and MED values for broadband UVB and for UVA were determined in 461 white subjects. When appropriate, the 95% reference intervals, including the 0.025 fractile and 0.975 fractile, were computed for the MED-UVB reference values (by means of parametric methods) and the MED-UVA reference values (by means of nonparametric methods). MED data were also converted to standard erythema doses (SEDs). As described elsewhere we observed a considerable overlap of MED values for all skin phototypes and confirmed that age and sex do not substantially influence the MED. The lower RLs observed for MED-UVB were 33 mJ cm(-2) (0.5 SEDs) and for MED-UVA 12.6 mJ cm(-2) (1.2 SEDs). The MED and SED findings from this investigation may serve as reference data for white individuals and give support to the clinician in differentiating between normal and pathologically abnormal photosensitivity. Although the MED data given here are limited to the phototest device used in the present study, the SED results establish comparability between our data and phototest results obtained from laboratories using different UV sources.

Background: The aggravating role of Staphylococcus aureus superantigens is well known in atopic dermatitis (AD) but has not yet been proven in psoriasis (PS)., Objective: We investigated the distribution of S aureus in the skin and nares of patients with AD, PS vulgaris, erythroderma, skin infections, and sepsis, and in healthy control subjects. A Staphylococcal enterotoxin test-reversed passive latex agglutination (SET-RPLAR) test was performed to determine Staphylococcal enterotoxins A, B, C, and D., Results: S aureus was cultivated from lesional skin of 22 of 25 patients with AD and 15 of 25 patients with PS. Isolated strains were toxigenic in 44% for patients with AD and in 36% for patients with PS. The activity of disease in AD and PS according to the Severity Scoring of Atopic Dermatitis (SCORAD) or Psoriasis Area and Severity Index score, respectively, correlated significantly (P = .001) with an isolated toxigenic strain in both diseases. S aureus from skin infections was toxigenic in half of the patients. All patients with erythroderma harbored S aureus, mostly on their skin. In AD, sepsis and skin infections, toxin C and in PS toxin B was most often detected. S aureus was cultured in 12% of healthy persons. These strains were toxin negative. The limitations of these investigations are that other potentially acting enterotoxins, such as toxic shock syndrome toxin-1, which may play a role in aggravating disease, were not investigated with our latex agglutination test., Conclusion: In this study, S aureus was present in more than 50% of patients with AD and PS. We found that the severity of AD and PS significantly correlated to enterotoxin production of the isolated S aureus strains.