Georgina Nagy

Endocannabinoids enhance lipid synthesis and apoptosis of human sebocytes via cannabinoid receptor-2-mediated signaling

We had previously shown that both locally produced endocannabinoids and exocannabinoids, via cannabinoid receptor‐1 (CB1), are powerful inhibitors of human hair growth. To further investigate the role of the cannabinoid system in pilosebaceous unit biology, we have explored in the current study whether and how endocannabinoids have an impact on human sebaceous gland biology, using human SZ95 sebocytes as cell culture model. Here, we provide the first evidence that SZ95 sebocytes express CB2 but not CB1. Also, prototypic endocannabinoids (arachidonoyl ethanolamide/anandamide, 2‐arachidonoyl glycerol) are present in SZ95 sebocytes and dose‐dependently induce lipid production and (chiefly apoptosis‐driven) cell death. Endocannabinoids also up‐regulate the expression of key genes involved in lipid synthesis (e.g., PPAR transcription factors and some of their target genes). These actions are selectively mediated by CB2‐coupled signaling involving the MAPK pathway, as revealed by specific agonists/antagonists and by RNA interference. Because cells with “silenced” CB2 exhibited significantly suppressed basal lipid production, our results collectively suggest that human sebocytes utilize a paracrine‐autocrine, endogenously active, CB2‐mediated endocannabinoid signaling system for positively regulating lipid production and cell death. CB2 antagonists or agonists therefore deserve to be explored in the management of skin disorders characterized by sebaceous gland dysfunctions (e.g., acne vulgaris, seborrhea, dry skin).—Dobrosi, N., Tóth, B. I., Nagy, G., Dózsa, A., Géczy, T., Nagy, L., Zouboulis, C. C., Paus, R., Kovács, L., Bíró, T. Endocannabinoids enhance lipid synthesis and apoptosis of human sebocytes via cannabinoid receptor‐2‐mediated signaling. FASEB J. 22, 3685–3695 (2008)

Regulatory T cells in atopic dermatitis: epidermal dendritic cell clusters may contribute to their local expansion

Background  Regulatory T cells (Tregs) have an essential role in tolerance and immune regulation. However, few and controversial data have been published to date on the role and number of these cells in atopic dermatitis (AD).

Immunological and Clinical Effects of Alphacalcidol in Patients with Psoriatic Arthropathy: Results of an Open, Follow-up Pilot Study

The aim of this study was to describe the effect of systemic alphacalcidol (1 OH vitamin D3) treatment on clinical and immunological parameters in patients with psoriatic arthropathy. Among the 19 patients investigated, 10 were treated with 0.25 microg oral alphacalcidol twice daily for 6 months, while 9 other patients served as controls. In the peripheral blood of the treated group but not in the controls, a statistically significant decrease was observed in the percentage of CD3/CD69-positive activated and CD8-positive interferon-gamma-producing T cells and in the serum level of interferon-gamma during the first 3 months and also in the clinical activity of the disease during the whole 6-month follow-up period. Our results show that systemic alphacalcidol treatment has an immunomodulatory effect on patients with psoriatic arthropathy. This effect is manifested by a short-term temporary decrease in type 1 immune responses and a continuous decrease in disease activity.

Usefulness of detection of complement activation products in evaluating SLE activity

Complement activation products, such as C1rs-C1inh, specific for the activation of the classical pathway, C3b(Bb)P, specific for the activation of the alternative pathway and SC5b-9, specific for common terminal pathway of the complement cascade, were measured in healthy donors and in patients with clinically active and inactive systemic lupus erythematosus (SLE). Plasma levels of C3b(Bb)P and SC5b-9 were moderately, those of C1rs-C1inhibitor (C1rs-C1inh) were markedly elevated in patients with clinically inactive SLE, compared with healthy controls. The difference between active and inactive stages of the disease was best reflected by C3b(Bb)P plasma concentration (P < 0.001), which also showed the highest correlation with the SLEDAI (Rs = 0.41 P < 0.001) and which was the most useful in distinguishing active and inactive sample pairs as well. The difference between SC5b-9 levels in the active and inactive stages was also significant (P = 0.007), while that of C1rs-C1inh did not differ significantly (P = 0.136). The correlation of the SLEDAI with SC5b-9 was 0.3 (P = 0.015), while with C1rs-C1inh it was 0.21 (P = 0.089). These findings suggest that the measurement of complement activation products, especially that of the alternative pathway, are sensitive markers of the activity of SLE and can be used for clinical purposes.

C1-inhibitor autoantibodies in SLE

The presence of anti-C1-inhibitor (anti-C1-INH) autoantibodies is a hallmark of acquired C1-inhibitor deficiency. However, only scarce data are available on their prevalence, diagnostic value, and/or significance in systemic lupus erythematosus (SLE). In a multicentre study, we determined the levels of autoantibodies to C1-inhibitor in sera from 202 patients with SLE and 134 healthy controls. Additional clinical and laboratory parameters, such as organ involvement, as well as anti-C1q, anti-double-stranded DNA antibody, erythrocyte sedimentation rate, C-reactive protein, C3 and C4 serum complement levels have been studied in patients. The level of anti-C1-INH IgG was significantly higher (p = 0.034) in SLE patients, than in the controls. A high anti-C1-INH level of ≥0.4 U/ml (mean of controls + 2 SD) was found in 17% of the patients, but in only 4% of the controls (p = 0.0003). The SLEDAI score was significantly higher (p = 0.048) and the duration of SLE was significantly longer (p = 0.0004) among patients with elevated anti-C1-INH levels compared with patients without this autoantibody (median disease duration 8 vs. 17 years, respectively). Anti-C1-INH level was not correlated with any other laboratory parameter or organ manifestation of the disease. These findings indicate that the anti-C1-INH level is higher in SLE patients than in healthy controls and furthermore, the anti-C1-INH level correlates with the duration and activity of the disease. Lupus (2010) 19, 634—638.

Severe skin inflammation and filaggrin mutation similarly alter the skin barrier in patients with atopic dermatitis

Filaggrin (FLG) deficiency is a well‐known predisposing factor for the development of atopic dermatitis (AD). Decreased FLG expression can be the result of haploinsufficiency or severe inflammation, which can cause acquired FLG alterations. FLG mutations are related to several clinical and laboratory parameters of AD; however, some recent data seem to contradict these associations.

The prevalence of obesity is increased in patients with late compared with early onset psoriasis

PURPOSE We compared the clinical and epidemiologic characteristics of early and late onset psoriasis with an emphasis on potential differences in the comorbidities associated with each subtype. METHODS An observational, multicenter study was performed, and associations between the age at the time of diagnosis and binary comorbidity outcomes were evaluated using multiple logistic regression analysis adjusted for age and other relevant confounders. RESULTS An increased prevalence of positive family history, psoriatic arthritis, and depression was observed in patients with early onset psoriasis. On the other hand, late onset psoriasis was more frequently associated with obesity and elevated waist circumference compared with early onset form. Elderly psoriatic patients (at the age of 75 years) with late onset psoriasis are at an especially high risk for obesity compared with individuals at the same age with an early onset disease. CONCLUSIONS The increased frequency of psoriasis in the family of early onset patients may suggest that manifestation of psoriasis at younger age is driven by strong genetic influence. However, such a remarkable association of abdominal obesity with late onset psoriasis may suggest that obesity can be one of the acquired factors that may predispose for the development of psoriasis in the elderly.

Regulatory T-cell subsets with acquired functional impairment: important indicators of disease severity in atopic dermatitis.

Our aim was to assess whether the presence of highly active effector T cells in atopic dermatitis (AD) is associated with changes in the number and/or function of regulatory T cells (Tregs). Flow cytometry was utilised to determine the percentage of CD4+ CD25bright CD127-/low FOXP3+ and skin-homing CLA+ CD4+ CD25bright FOXP3+ Tregs in healthy controls and AD patients. The correlation between disease severity and Treg percentages was estimated. Treg suppressor activity and cell proliferation were measured after T-cell stimulation. Significantly increased percentages of Tregs were found in AD patients compared to healthy individuals, and significant correlation between the frequency of Tregs and disease severity was also detected. The otherwise normal suppressor activity of Tregs decreased in the presence of Staphylococcus enterotoxin B (SEB). In conclusion, the continuous presence of SEB can trigger an acquired functional impairment of Tregs in AD patients and the correlation between the increased frequency of Tregs and disease severity supports their important role in AD pathogenesis.

Transfection of pseudouridine-modified mRNA encoding CPD-photolyase leads to repair of DNA damage in human keratinocytes: a new approach with future therapeutic potential

UVB irradiation induces harmful photochemical reactions, including formation of Cyclobutane Pyrimidine Dimers (CPDs) in DNA. Accumulation of unrepaired CPD lesions causes inflammation, premature ageing and skin cancer. Photolyases are DNA repair enzymes that can rapidly restore DNA integrity in a light-dependent process called photoreactivation, but these enzymes are absent in humans. Here, we present a novel mRNA-based gene therapy method that directs synthesis of a marsupial, Potorous tridactylus, CPD-photolyase in cultured human keratinocytes. Pseudouridine was incorporated during in vitro transcription to make the mRNA non-immunogenic and highly translatable. Keratinocytes transfected with lipofectamine-complexed mRNA expressed photolyase in the nuclei for at least 2days. Exposing photolyase mRNA-transfected cells to UVB irradiation resulted in significantly less CPD in those cells that were also treated with photoreactivating light, which is required for photolyase activity. The functional photolyase also diminished other UVB-mediated effects, including induction of IL-6 and inhibition of cell proliferation. These results demonstrate that pseudouridine-containing photolyase mRNA is a powerful tool to repair UVB-induced DNA lesions. The pseudouridine-modified mRNA approach has a strong potential to discern cellular effects of CPD in UV-related cell biological studies. The mRNA-based transient expression of proteins offers a number of opportunities for future application in medicine.

Altered Peripheral Invariant Natural Killer T Cells in Atopic Dermatitis

BackgroundConflicting data exist on the number of invariant NKT (iNKT) cells in atopic dermatitis (AD); furthermore, no data have been published on their functional capacity.MethodsThe frequency and number of circulating CD3+6B11+ iNKT cells and their CD4+ and CD4− subpopulations were evaluated in peripheral blood obtained from 41 patients with AD by four-color flow cytometry. Likewise, functional properties of iNKT cells were measured by five-color intracellular cytokine staining.ResultsThe number and percentage of total iNKT cells and their CD4/CD8 subpopulations were significantly lower than the controls. Of further importance, the CD4−CD8− (double negative, DN) iNKT subgroup showed the strongest positive correlation with total iNKT cells. In addition, the DN subgroup exhibited the most pronounced functional alteration with significantly decreased levels of intracellular IFNγ and significantly increased levels of intracellular IL-4 in AD patients compared with the controls.ConclusionThe significantly altered number and cytokine production of iNKT cells from AD patients suggests that these cells may play an important role in the pathogenesis of AD.