Augmented production of transforming growth factor-β by cultured peripheral blood mononuclear cells from patients with systemic sclerosis

We sought to determine whether the spontaneous production of transforming growth factor-β (TGF-β) by peripheral blood mononuclear cells (PBMC) is increased in patients with systemic sclerosis (SSc). Culture supernatants of PBMC from SSc patients (n=88) and healthy controls (n=44) were analyzed by enzyme-linked immunosorbent assay. The production of active TGF-β1 and total (active and latent) TGF-β1 by PBMC from patients with limited cutaneous SSc (lSSc) and by PBMC from patients with diffuse cutaneous SSc (dSSc) was significantly elevated compared to the production by PBMC from normal controls. Production of active TGF-β1 by dSSc PBMC was higher than that by lSSc PBMC, although not significantly. Patients with PBMC with increased active or total TGF-β1 production showed significantly shorter disease duration than patients with PBMC with normal production levels. PBMC from patients without anticentromere antibody showed enhanced active TGF-β1 production more frequently than those from patients with anticentromere antibody. PBMC from SSc patients more frequently showed enhanced total TGF-β2 production than PBMC from normal controls. Among each leukocyte subset, spontaneous production of total TGF-β1 was significantly higher in cultured peripheral monocytes/macrophages, but not in T cells, B cells, or NK cells, from patients than from normal controls. Thus, the enhanced production of TGF-β by PBMC may contribute to the disease process in SSc     

Activation of peroxisome proliferator-activated receptor-γ inhibits transforming growth factor-β1 induction of connective tissue growth factor and extracellular matrix in hypertrophic scar fibroblasts in vitro

Peroxisome proliferator-activated receptor-γ (PPAR-γ) ligands have been recently reported to have beneficial effects on organ fibrosis. However, their effects on extracellular matrix (ECM) turnover in hypertrophic scar fibroblasts (HSFs), and the related molecular mechanisms are unknown. HSFs were cultured and exposed to different concentration PPAR-γ ligands in the presence of transforming growth factor-β1 (TGF-β1). In growth-arrested HSFs, a PPAR-γ natural ligand (15-deoxy-D12,14-prostaglandin J2, 15d-PGJ2) and a synthetic ligand (GW7845) dose-dependently attenuated TGFβ1-induced expression of Connective tissue growth factor (CTGF), collagens and fibronectin. Furthermore, the suppression of CTGF mRNA and protein expression are relieved by pretreatment with an antagonist of PPAR-γ (GW9662). Moreover, GW7845 and 15d-PGJ2 partially inhibited the expression and phosphorylation of the TGF-β1/Smad pathway. These results suggest that in TGFβ1-stimulated HSFs, PPAR-γ ligands caused an antiproliferative effect and reduced ECM production through mechanisms that included reducing CTGF expression, and a crosstalk between PPAR-γ and Smad may be involved in the inhibitory effects of PPAR-γ ligands.     

Rising trends in incidence of cutaneous malignant melanoma and their future projections in Catalonia,Spain: increasing impact or future epidemic?

Background During the past decades, there has been a substantial increase in the incidence of cutaneous malignant melanoma (CMM) among all Caucasian populations. Spain presents one of Europe’s lowest incidence and mortality rates. Objective The aim of this study was to analyse the recent trends of CMM incidence and mortality in a region with lower incidence as well as to project their future trends. Methods Cutaneous malignant melanoma incidence data were provided by the Tarragona and Girona population‐based cancer registries and mortality data were provided by the Mortality Registry of Catalonia. Time trends of incidence and mortality rates by CMM were assessed through the estimated annual percentages of change of the incidence and mortality age‐standardized rates to the World Standard Population. Projections were based on a Bayesian age–period–cohort model using second order autoregressive effects on age. Results During the last 20 years CMM incidence has increased substantially at a faster rate than any other neoplasms in Catalonia, particularly among women and this trend will probably continue for the next several years. Nevertheless, CMM mortality trends have been and probably will remain stable during this period. Conclusion Improvements in preventive activities should be implemented to decrease incidence and mortality from this cancer. Monitoring stage‐specific trends in CMM incidence can assess the impact of preventive strategies; for this reason more complete information on diagnostic features of CMM patients in the Spanish population‐based cancer registries are necessary.     

Effects of tacrolimus on the expression of nuclear factor-κB and glucocorticoid receptor by HaCaT cells in vitro

Objective To investigate the effect of tacrolimus on the expression of nuclear factor-κB (NF-κB) in HaCaT cells stimulated by tumor necrosis factor-α(TNF-α),and on the expression of glucocorticoid receptor (GR)α and β in untreated HaCaT cells in vitro.Methods Cultured Ha CaT cells were treated with TNF-α(10μg/L) only,combination of TNF-α(10μg/L) and various concentrations (10-8mol/L, 10-7mol/L,10-6moL/L) of tacrolimus or tacrolimus of different concentrations only.After additional 12-,24-, 36- or 48-hour cnlture, Westem blot and immunofluorescenee-confocal laser scanning microscopy were used to detect the expressions of NF-κB,GRα and GRβ in HaCaT cells.Those untreated HaCaT cells served as the control.Results The relative protein expression level of NF-κB was increased in HaCaT cells after treatment with TNF-α for 24 and 48 hours zompared with untreated ceils (0.73±0.0316 and 0.8925±0.0171 vs 0.4988±0.03506,both P<0.05);however,the increase in NF-κB expression was inhibited by the combination treatment with tacrolimus,and the relative expression level of NF-κB protein was 0.6825±0.0263.0.6200±0.0163 and 0.5575±0.0299 in HaCaT cells treated with TNF-α plus tacrolimus of 10-8mol/L 10-7mol/L and 10-6mol/L,respectively;the difference was significant etween TNF-α-treated cells and those dealt with the combination of NF-α and tacrolimus of 10-7 or 10-6 mol/L (both P<0.05).No significant difference was observed in the expression of NF-κB by HaCaT cells between different time oints treated with tacrolimus of 10-8,10-7 or 10-6 mol/L.Also,there was no zignificant difference in the expression of GRα or GRβ between untreated HaCaT cells and those treated with tacrolimus of 10-8, 10-7 or 10-6 mol/L at any time point.Conclusions Tacrolimus ould inhibit the expression of NF-κB by TNF-α-stimulated HaCaT cells,but does not affect the expression of GRα or GRβ,in untreated HaCaT cells.     

Subcutaneous administration of polymerized type I collagen downregulates interleukin (IL)-17A, IL-22 and transforming growth factor-β1 expression, and increases Foxp3-expressing cells in localized scleroderma

Background. Localized scleroderma (LS) is a disfiguring inflammatory autoimmune disease of the skin and underlying tissue. As in systemic sclerosis, a key feature is the presence of T cells in inflammatory lesions. Aim. To evaluate the effect of polymerized type I collagen vs. methylprednisolone (MP) in LS, and to determine the influence of this polymerized collagen (PC) on CD4+ peripheral T cells expressing interleukin (IL)‐4, IL‐17A, interferon‐γ and Forkhead box protein (Foxp)3, and on cells expressing transforming growth factor (TGF)‐β1, IL‐17A, IL‐22 and Foxp3 in the skin. Methods. In total, 16 patients with LS were treated for 3 months with monthly subcutaneous intralesional injections of 0.1 mL MP (giving a total dose of 20 mg/mL each month) and 15 patients were treated, with weekly subcutaneous intralesional injections of PC, ranging from 0.2 mL (equivalent to 1.66 mg collagen) for a lesion of 50 mm in size, up to a maximum of 1.0 mL (8.3 mg collagen) for a lesion > 100 mm in size, and followed up for a further 6 months. Skin biopsies were obtained from lesions at baseline (before treatment) and 9 months later (6 months after treatment end). Tissue sections were evaluated by histology and immunohistochemistry (IL‐17A, IL‐22, TGF‐β1 and Foxp3). CD4+ T‐cell subsets were determined in peripheral blood by flow cytometry. Results. Abnormal tissue architecture was seen in the biopsies taken from patients treated with MP, whereas the PC treatment restored normal skin architecture. PC downregulated pro‐inflammatory/profibrotic cytokine expression in peripheral cells, and upregulated the number of regulatory T cells (Tregs) in skin. PC was safe and well tolerated. Conclusions. PC is not only an antifibrotic/fibrolytic agent but also an immunomodulator biodrug that restores the balance between T helper (Th)1, Th2, Th17 and Tregs, downregulates production of pro‐inflammatory or profibrogenic cytokines (IL‐17A, IL‐22 and TGF‐β1), and renews skin architecture, without adverse effects.     

What is really in control of skin immunity: lymphocytes,dendritic cells,or keratinocytes? facts and controversies

The pathophysiology of atopic dermatitis is still under discussion. Although it is widely accepted that environmental factors and a genetic predisposition are essential, the role of the innate and adaptive immune system and the functional cascade of the cells involved is still unclear. A concept that integrates all immune cells as equally essential has allure. In addition, barrier abnormalities due to mutations of the gene coding for filaggrin and down-regulation of antimicrobial peptides, such as LL-37 and β-defensins 2 and 3, were very recently found to be relevant for the pathogenesis of atopic dermatitis.