Differential localization of TGF-beta-precursor isotypes in psoriatic human skin

Mesenchymal stem cell-derived exosomes decrease Hyperplasia in Psoriasis by inducing transforming growth factor β2 (TGF-β2)

BACKGROUND

Psoriasis, a chronic inflammatory skin disease, is increasingly effectively managed with the targeted immunotherapy; however, long-term immunotherapy carries health risks, and loss of response. Therefore, we need to develop the alternative treatment strategies. Mesenchymal stem/stromal cell (M.S.C.) exosomes stand out for their remarkable immunomodulatory properties, gaining widespread recognition. This study investigated whether M.S.C. exosomes can reduce psoriasis-induced hyperplasia by inducing Transforming Growth Factor beta 2 (TGF-beta2) signaling.

METHODOLOGY

Exosomes were isolated from M.S.C.s by ultracentrifugation. Then, scanning electron microscopy was used for the morphology of exosomes. To ascertain the exosome concentration, the Bradford test was used. To ascertain the cellular toxicity of exosomes in Human Umbilical Vein Endothelial Cells ( H.U.V.E.C), an MTT experiment was then conducted. Real-time PCR was used to quantify TGF beta2 expression levels, whereas an ELISA immunosorbent assay was used to determine the protein concentration of TGF beta2.

RESULTS

In this study, the exosomes of 15-30 nm in size that were uniform, and cup-shaped were isolated. Moreover, the IC50 value for this Treatment was calculated to be 181.750 µg/ml. The concentration of TGF-β2 gene in the target cells significantly increased following Treatment with the exosomes. Furthermore, the expression level of the studied gene significantly increased due to the Treatment.

CONCLUSION

Upregulating the expression of TGF-β2 in psoriatic cells via TGF-β2 signaling is one way exosomes can help reduce hyperplasia.

An Overview of Growth Factors as the Potential Link between Psoriasis and Metabolic Syndrome

Psoriasis is a chronic, complex, and immunologically mediated systemic disease that not only affects the skin, but also the joints and nails. It may coexist with various other disorders, such as depression, psoriatic arthritis, cardiovascular diseases, diabetes mellitus, and metabolic syndrome. In particular, the potential link between psoriasis and metabolic syndrome is an issue worthy of attention. The dysregulation of growth factors could potentially contribute to the disturbances of keratinocyte proliferation, inflammation, and itch severity. However, the pathophysiology of psoriasis and its comorbidities, such as metabolic syndrome, remains incompletely elucidated. Growth factors and their abnormal metabolism may be a potential link connecting these conditions. Overall, the objective of this review is to analyze the role of growth factor disturbances in both psoriasis and metabolic syndrome.

BMPR1a is required for the optimal TGF-β1 dependent CD207+ Langerhans cell differentiation and limits skin inflammation via CD11c+ cells

The cytokine TGF-β1 induces epidermal Langerhans cell (LC) differentiation from human precursors, an effect mediated via bone morphogenetic protein receptor 1a (BMPR1a)/ALK3 signaling, as revealed from ectopic expression and receptor inhibition studies. Whether TGF-β1-BMPR1a signaling is required for LC differentiation in vivo remained incompletely understood. We found that TGF-β1 deficient mice show defective perinatal expansion and differentiation of LCs. LCs can be identified within the normal healthy human epidermis by anti-BMPR1a immunohistology staining. Deletion of BMPR1a in all (vav⁺) hematopoietic cells revealed that BMPR1a is required for the efficient TGF-β1-dependent generation of CD207⁺ LC-like cells from CD11c⁺ intermediates in vitro. Similarly, BMPR1a was required for the optimal induction of CD207 by preformed MHCII⁺ epidermal resident LC precursors in the steady-state. BMPR1a expression is strongly upregulated in epidermal cells in psoriatic lesions, and BMPR1a^ΔCD11c mice showed a defect in the resolution phase of allergic and psoriatic skin inflammation. Moreover, while LCs from these mice expressed CD207, BMPR1a counteracted LC activation and migration from skin explant cultures. Therefore, TGF-β1-BMPR1a signaling seems to be required for the efficient induction of CD207 during LC differentiation in the steady-state, and bone marrow-derived lesional CD11c⁺ cells may limit established skin inflammation via enhanced BMPR1a signaling.

Fibrosis Is a Basement Membrane-Related Disease in the Cornea: Injury and Defective Regeneration of Basement Membranes May Underlie Fibrosis in Other Organs

Every organ develops fibrosis that compromises functions in response to infections, injuries, or diseases. The cornea is a relatively simple, avascular organ that offers an exceptional model to better understand the pathophysiology of the fibrosis response. Injury and defective regeneration of the epithelial basement membrane (EBM) or the endothelial Descemet's basement membrane (DBM) triggers the development of myofibroblasts from resident corneal fibroblasts and bone marrow-derived blood borne fibrocytes due to the increased entry of TGF beta-1/-2 into the stroma from the epithelium and tears or residual corneal endothelium and aqueous humor. The myofibroblasts, and disordered extracellular matrix these cells produce, persist until the source of injury is removed, the EBM and/or DBM are regenerated, or replaced surgically, resulting in decreased stromal TGF beta requisite for myofibroblast survival. A similar BM injury-related pathophysiology can underly the development of fibrosis in other organs such as skin and lung. The normal liver does not contain traditional BMs but develops sinusoidal endothelial BMs in many fibrotic diseases and models. However, normal hepatic stellate cells produce collagen type IV and perlecan that can modulate TGF beta localization and cognate receptor binding in the space of Dissé. BM-related fibrosis is deserving of more investigation in all organs.

Bone morphogenetic protein signaling regulates skin inflammation via modulating dendritic cell function

BACKGROUND

Bone morphogenetic proteins (BMPs) are members of the TGF-β family that signal via the BMP receptor (BMPR) signaling cascade, distinct from canonical TGF-β signaling. BMP downstream signaling is strongly induced within epidermal keratinocytes in cutaneous psoriatic lesions, and BMP7 instructs monocytic cells to acquire characteristics of psoriasis-associated Langerhans dendritic cells (DCs). Regulatory T (Treg)-cell numbers strongly increase during psoriatic skin inflammation and were recently shown to limit psoriatic skin inflammation. However, the factors mediating Treg-cell accumulation in psoriatic skin currently remain unknown.

OBJECTIVE

We sought to investigate the role of BMP signaling in Treg-cell accumulation in psoriasis.

METHODS

The following methods were used: immunohistology of patients and healthy controls; ex vivo models of Treg-cell generation in the presence or absence of Langerhans cells; analysis of BMP versus canonical TGF-β signaling in DCs and Treg cells; and modeling of psoriatic skin inflammation in mice lacking the BMPR type 1a in CD11c⁺ cells.

RESULTS

We here demonstrated a positive correlation between Treg-cell numbers and epidermal BMP7 expression in cutaneous psoriatic lesions and show that unlike Treg cells from healthy skin, a portion of inflammation-associated Treg cells exhibit constitutive-active BMP signaling. We further found that BMPR signaling licenses inflammation-associated Langerhans cell/DC to gain an enhanced capacity to promote Treg cells via BMPR-mediated CD25 induction and that this effect is associated with reduced skin inflammation.

CONCLUSIONS

Psoriatic lesions are marked by constitutive high BMP7/BMPR signaling in keratinocytes, which instructs inflammatory DCs to gain enhanced Treg-cell-stimulatory activity. Locally secreted BMP7 can directly promote Treg-cell generation through the BMP signaling cascade.

Smad7 in psoriasis vulgaris patients: A clinical and immunohistochemical study

BACKGROUND

Psoriasis is an inflammatory disease that is mostly immune-derived. It causes proliferation of skin cells, forming plaques. Psoriasis etiology is unknown. It might be multifactorial.

AIMS

This work aimed to study Smad7 expression in psoriasis vulgaris patients in comparison with normal skin.

PATIENTS/METHODS

Thirty patients with psoriasis vulgaris in comparison with 20 age- and sex-matched seemingly healthy individuals were selected. We used psoriasis area and severity index (PASI) to evaluate psoriasis severity. Skin biopsies were prepared from skin lesions (30), perilesions (30) and control (20) groups for histopathological and immunostaining evaluation of Smad7.

RESULTS

Smad7 was progressively upregulated in proliferating keratinocytes from controls (58.18 ± 30.93) to perilesional (106 ± 38.93) and lesional (156.33 ± 62.01) skin (P < .001). Also, dermal inflammatory cells showed upregulation of Smad7 expression from control skin (40 ± 28.28) to skin lesions (137.33 ± 73.86) (P < .010). Smad7 expression showed a positive significant correlation with psoriasis severity (r = .452; P < .012).

CONCLUSION

Smad7 may be involved in increased keratinocyte proliferation as well as skin inflammation in psoriasis vulgaris patients.

BMP7 aberrantly induced in the psoriatic epidermis instructs inflammation-associated Langerhans cells

BACKGROUND

Epidermal hyperplasia represents a morphologic hallmark of psoriatic skin lesions. Langerhans cells (LCs) in the psoriatic epidermis engage with keratinocytes (KCs) in tight physical interactions; moreover, they induce T-cell-mediated immune responses critical to psoriasis.

OBJECTIVE

This study sought to improve the understanding of epidermal factors in psoriasis pathogenesis.

METHODS

BMP7-LCs versus TGF-β1-LCs were phenotypically characterized and their functional properties were analyzed using flow cytometry, cell kinetic studies, co-culture with CD4 T cells, and cytokine measurements. Furthermore, immunohistology of healthy and psoriatic skin was performed. Additionally, in vivo experiments with Jun^f/fJunB^f/fK5cre-ER^T mice were carried out to assess the role of bone morphogenetic protein (BMP) signaling in psoriatic skin inflammation.

RESULTS

This study identified a KC-derived signal (ie, BMP signaling) to promote epidermal changes in psoriasis. Whereas BMP7 is strictly confined to the basal KC layer in the healthy skin, it is expressed at high levels throughout the lesional psoriatic epidermis. BMP7 instructs precursor cells to differentiate into LCs that phenotypically resemble psoriatic LCs. These BMP7-LCs exhibit proliferative activity and increased sensitivity to bacterial stimulation. Moreover, aberrant high BMP signaling in the lesional epidermis is mediated by a KC intrinsic mechanism, as suggested from murine data and clinical outcome after topical antipsoriatic treatment in human patients.

CONCLUSIONS

These data indicate that available TGF-β family members within the lesional psoriatic epidermis preferentially signal through the canonical BMP signaling cascade to instruct inflammatory-type LCs and to promote psoriatic epidermal changes. Targeting BMP signaling might allow to therapeutically interfere with cutaneous psoriatic manifestations.

Evaluation of selected mechanisms of immune tolerance in psoriasis

Introduction

Psoriasis is an autoimmune disease with an excessively aberration of the Th17/Treg balance and deficiency of anti-inflammatory cytokines.

Aim

Evaluation of Treg markers expression in the lesional and perilesional psoriatic skin and serum anti-inflammatory cytokines in male psoriatic patients compared to healthy men.

Material and methods

Treg markers (FoxP3+, CD4, CTLA-4, CD25/IL-2R, CD39/ENTPD1, IL-7R/CD127, CD3) and tissue expression of protective cytokines (IL-10, IL-35, TGF-β) in the lesional and perilesional psoriatic skin from 33 male patients compared to 6 healthy skin samples were evaluated by immunohistochemistry. ELISA was used to assess serum IL-10, IL-35 and TGF-β levels.

Results

The serum levels of IL-35, IL-10 and TGF-β1 were higher in psoriatic patients than in controls but without any statistically significant relationship with PASI. The expressions of IL-35, CD4, IL-10, TGF-β1, CD3, FOXP3 and CD25/IL-2R were varied in different experimental groups (p < 0.05). The level of IL-35 was the lowest in psoriatic lesions (p < 0.05) compared to perilesional skin and to controls. CD4, IL-10 and TGF-β1 expressions were higher (p < 0.05) in perilesional skin than in lesions. TGF-β1 expression was decreased in psoriatic lesions compared to controls (p < 0.05). CD25/IL2R expression was increased in healthy skin compared to psoriatic skin (p < 0.05). FOXP3 expression was elevated in psoriatic skin compared to healthy and perilesional one. There was no difference between experimental groups in CTLA-4, IL7R/CD127 and CD39/ENTPD1 expression.

Conclusions

The differences between the levels of protective cytokines and expression of Treg markers might explain the inflammation development in psoriasis.

Clinical and molecular evaluation of therapy with the use of cyclosporine A in patients with psoriasis vulgaris

BACKGROUND

Psoriasis course involves increased secretion of pro-inflammatory cytokines, among others, a beta transforming growth factor (TGFβs) and its receptors. Cyclosporine A (CsA), an immunosuppressive medicine with the molecular mechanism of operation connected with the properties of cell cycle suppression, is often used in the treatment of severe forms of psoriasis. The efficacy of therapy is assessed based on the disease clinical progression indexes - Psoriasis Area and Severity Index (PASI), body surface area (BSA), and Dermatology Life Quality Index (DLQI). The aim of the study was the evaluation of the efficacy of the CsA treatment of patients with psoriasis vulgaris, based on the clinical parameters and an assessment of the expression profiles of TGFβs and TGFβRs, depending on the concurrent diabetes and metabolic syndrome.

METHODS

The group under study composed of 32 patients (15 with the metabolic syndrome, seven with diabetes) treated with CsA for 84 days. The molecular analysis included extraction of RNA, assessment of TGβF1-3, TGFβRI-III gene expression with the use of the RTqPCR method. The clinical assessment of the effects of this pharmacotherapy involved evaluation of the parameters: PASI, BSA, DLQI before therapy commencement, on the 42nd and 84th days of therapy.

RESULTS

A statistically significant change in the transcription activity of TGFβ1 in patients with and without diabetes (P = 0.018) and patients with and without metabolic syndrome (P = 0.023) was shown that on the 84th day of therapy.

CONCLUSIONS

TGFb1 may be claimed as the supplementary molecular marker to evaluate the efficacy of CsA therapy. It seems that systemic diseases have an effect on the efficacy of the applied pharmacotherapy and the course of psoriasis.

Serum and tissue expression of transforming growth factor beta 1 in psoriasis

BACKGROUND

In psoriasis, keratinocyte hyperplasia may be explained by imbalance of growth factors responsible for epidermal proliferation and altered metabolism of their receptors. Transforming growth factor-beta 1 (TGF-beta1) implications in the pathogenesis of psoriasis can be attributed to several mechanisms besides keratinocyte cell cycle inhibition.

OBJECTIVES

To evaluate the relation between serum and tissue levels of TGF-beta1 in psoriasis and their correlation with disease parameters.

PATIENTS AND METHODS

Serum and punch biopsy of involved and non-involved skin of 22 patients with psoriasis vulgaris and 10 controls were collected for quantification of TGF-beta1 by enzyme-linked immunosorbent assay kit.

RESULTS

Serum level of TGF-beta1 in psoriatic patients was higher than controls in a statistically non-significant manner. Correlations between serum level of TGF-beta1 and extent of the disease (P = 0.007) and Psoriasis Area and Severity Index (PASI) score (P = 0.005) were observed. Mean tissue levels of TGF-beta1 were highest in psoriatic lesions in contrast to normal skin of psoriatic patients and healthy controls, but not statistically significant. Correlation between tissue levels of TGF-beta1 in non-involved skin and extent of the disease (P = 0.007) and PASI score (P = 0.013) was detected. Correlation was detected between levels of TGF-beta1 in psoriatic plaques and serum of patients (P = 0.035), but not between levels of TGF-beta1 in non-involved skin and serum.

CONCLUSIONS

Tissue expression of TGF-beta1 in psoriasis may be affected by the stage of development of the lesion. The direct relation between TGF-beta1 in psoriatic plaques and serum imply that the mechanisms for TGF-beta1 production and release in both these compartments may be related.

Plasma TGF-beta1, TIMP-1, MMP-1 and IL-18 as a combined biomarker of psoriasis activity

Plasma levels of transforming growth factor (TGF)-beta1, tissue inhibitors of metalloproteinases (TIMP)-1, matrix metalloproteinase (MMP)-1 and interleukin (IL)-18 when analyzed separately demonstrate an association with psoriasis severity and treatment efficacy. To determine the highest correlation with the Psoriasis Area and Severity Index (PASI) score we carried out an analysis of these four proteins combined as the TTMI score. Concentrations of proteins were measured using an enzyme immunoassay in the plasma of 32 patients with chronic plaque-type psoriasis. The concentration of each biomarker was multiplied by the respective coefficient and the final individual TTMI score was the sum of these four values. TGF-beta1, TIMP-1 and IL-18 demonstrated significant positive correlation, whereas MMP-1 demonstrated significant negative correlation with the PASI score. The TTMI score calculated for individual patients varied from -79620 to 145713 (43050+/-8081) and demonstrated significant correlation with the PASI score. The lowest TTMI mean value was observed in patients with a PASI score <16 and the highest value was in patients with a PASI score >20. The combined measurement of plasma TGF-beta1, TIMP-1, MMP-1 and IL-18 has superior value as a biomarker of psoriasis activity in comparison with their separate analysis.

TGF-β1 gene polymorphism in psoriasis vulgaris

Overexpression of TGF-beta(1) has been implicated in the pathology of many inflammatory diseases, including psoriasis. This study was performed to investigate the association between TGF-beta(1) single nucleotide polymorphism and susceptibility for psoriasis vulgaris. DNA from 78 patients with psoriasis vulgaris and 74 healthy volunteers was investigated. Polymorphism of TGF-beta(1) gene in codon 10 (T/C) and codon 25 (G/C) was evaluated by PCR-SSP and the results were compared between group of psoriatic patients, divided into early onset of psoriasis (type I) and late onset of psoriasis (type II) subgroups, and control healthy subjects. Frequencies in genotypes were similar between patients and control group (p >0.7), but between type I and type II psoriasis patients highly significant difference was found (p <0.0003). Higher frequency of CC/GG (intermediate producer) and TC/GG (high producer) was noted in the type I group, but the second high producer genotype (TT/GG) was more common in type II group. Also between type II psoriasis patients and healthy controls statistically significant difference was found (p <0.000001). In analyzing frequencies of carriage and alleles no significant differences were found. TGF-beta(1) gene polymorphism in codon 10 and 25 is not associated with susceptibility to psoriasis vulgaris, but may be important for the type of the disease.

Plasma and scales levels of interleukin 18 in comparison with other possible clinical and laboratory biomarkers of psoriasis activity

The aim of the study was to assess plasma and scales levels of interleukin (IL) 18 collected from psoriatic patients with different disease activity. IL-18 concentrations were measured using an enzyme immunoassay in the plasma and scales of 34 patients with chronic plaque type psoriasis. IL-18 levels were analysed with respect to plasma-transforming growth factor beta1 (TGF-beta1), the disease duration and the duration of the present relapse, and psoriasis area and severity index (PASI). Plasma IL-18 concentration varied from 90 to 1300 pg ml-1 and means (368.2 +/- 42.4 pg ml-1) were significantly elevated in comparison with healthy controls (205.9 +/- 31.8 pg ml-1). The presence of IL-18 was also demonstrated in scales from skin lesions. Treatment caused a significant decrease of plasma IL-18 concentration to 250.2 +/- 13.8 pg ml-1. There was a significant correlation between plasma IL-18 levels and PASI values (r = 0.554). There was no correlation between IL-18 concentration in scales and PASI, between IL-18 concentrations in plasma and scales, and between plasma IL-18 and the disease duration or duration of present relapse. Plasma TGF-beta1 concentration demonstrated a significant correlation with PASI (r = 0.353), but not with IL-18 levels in plasma (r = 0.063) and scales (0.141). The sum of plasma levels of IL-18 and TGF-beta1 divided by the optimal coefficient demonstrated a statistically significant correlation with the highest r-value. The findings confirm an association between plasma IL-18 concentration and psoriasis severity. Moreover, it was shown that combined measurement of IL-18 and TGF-beta1 in plasma can be considered as a possible biomarker of psoriasis activity.

Effect of psoriasis activity on metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 in plasma and lesional scales

The aim of this study was to evaluate the association between psoriasis severity and concentrations of matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in plasma and scales from psoriatic lesions, measured with an enzyme immunoassay in 24 patients and analysed with respect to psoriasis area and severity index (PASI). The mean plasma concentrations of both proteins in psoriatic patients significantly exceeded the control values. The proteins were also detectable in scales. There was a significant correlation between plasma MMP-1 concentration and the disease duration. The PASI values showed significant positive correlation with plasma TIMP-1 and significant negative correlation with MMP-1 content in scales. The highest plasma MMP-1 concentration was observed in patients with mild forms whereas the highest plasma TIMP-1 concentrations were demonstrated in severe forms of psoriasis. Our results confirm the role of these proteins in pathogenesis of psoriasis. In severe forms, a decrease in both MMP-1 and TIMP-1 was observed in scales, suggesting their insufficient tissue expression, which can be a crucial element of psoriasis aggravation.

Effect of psoriasis treatment on plasma concentrations of metalloproteinase-1 and tissue inhibitor of metalloproteinases-1

AIM

The aim of this study was to evaluate the effect of psoriasis treatment on plasma concentrations of metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinases-1 (TIMP-1) with respect to disease severity.

METHODS

MMP-1 and TIMP-1 were measured using an enzyme immunoassay in plasma of 32 patients before and after topical treatment. Data were analysed with respect to baseline values of the Psoriasis Area and Severity Index (PASI).

RESULTS

Baseline plasma concentrations of both TIMP-1 and MMP-1 (1487 +/- 102 and 21.0 +/- 2.5 ng/mL, respectively) were significantly higher (P = 0.02 and 0.03, respectively) than normal. Both TIMP-1 and MMP-1 decreased significantly after completion of treatment to values similar to normal (1112 +/- 127 and 11.3 +/- 1.3 ng/mL, respectively). There was a significant positive correlation (r = 0.522) between baseline PASI and TIMP-1 values. Significant differences were observed between baseline TIMP-1 concentrations in groups with PASI < 15 and PASI > 20. Baseline values (1697 +/- 162 ng/mL) in patients with severe course of the disease (PASI > 20) were significantly elevated in comparison to normal values. Treatment caused a decrease in TIMP-1 plasma concentrations in all groups, but a significant difference was noted only in patients with pretreatment PASI > 20. Baseline MMP-1 concentrations exceeded significantly normal values only in patients with PASI < 15 (27.2 +/- 6.3 ng/mL) and 15-20 (18.4 +/- 1.4 ng/mL). Treatment caused a significant decrease in MMP-1-values in all groups to levels similar to normal.

CONCLUSIONS

Our results confirm the role of TIMP-1 and MMP-1 in the pathogenesis of psoriasis. Pretreatment plasma TIMP-1 increased whereas MMP-1 decreased in patients with a more severe course of the disease. However, successful treatment causes normalization of these plasma protein concentrations irrespective of psoriasis baseline activity.

Differential expression of TGF-beta isoforms during differentiation of HaCaT human keratinocyte cells: implication for the separate role in epidermal differentiation

The three mammalian isoforms of transforming growth factor-beta(TGF-beta1, beta2, beta3) are potent regulators of cell growth, differentiation, and extracellular matrix deposition. To study their role in skin differentiation, we investigated the expression of TGF-beta isoforms on cell growth and differentiation induction of the human keratinocyte cell line, HaCaT by elevating the Ca(2+) concentration. An ELISA and RT-PCR assay revealed secreted TGF-beta 1 protein and TGF-beta 1 mRNA were increased during calcium-induced differentiation. In contrast, major differences were seen for TGF-beta 2 and TGF-beta 3 mRNA which were decreased during differentiation, but TGF-beta 2 and TGF-beta3 protein were not evident on an ELISA. These results suggest different functions for each TGF-beta isoforms in epidermal differentiation, such that TGF-beta 1 is associated with the more differentiated state, and TGF-beta 2 and TGF-beta 3 may be associated the more proliferated state.

Current concepts in the immunopathogenesis of psoriasis

There is much evidence to support the concept that psoriasis is a type 1 autoimmune disease, primarily mediated by interferon gamma and other inflammatory cytokines. There has been renewed interest in the role of components of the innate immune system, however,and it may be that overlap between the innate and acquired arms of the immune system can better explain immunopathogenesis in psoriasis. Relevant cell types, receptors, and immune mediators within these traditional boundaries of the immune system are discussed.Finally, pathogenic contributions from important psoriatic mouse models and recent genomic data using the new gene chip technology are elaborated.

Proliferating keratinocytes are putative sources of the psoriasis susceptibility-related EDA+ (extra domain A of fibronectin) oncofetal fibronectin

The extra domain A of fibronectin (EDA+ oncofetal isoform of fibronectin was recently reported to be overexpressed in psoriatic uninvolved epidermis. It has been proposed that the abnormal presence of EDA+ oncofetal protein at the dermal-epidermal junction in the uninvolved skin may provide the "psoriatic" environment in which keratinocytes are in a preactivated state with regard to mitogenic signals (e.g., T cell lymphokines). To determine the possible sources of cellular fibronectin in the non-lesional psoriatic skin, we aimed to investigate whether keratinocytes could produce the EDA+ oncofetal form of fibronectin. RT-PCR studies revealed that both cultured normal keratinocytes and HaCaT cells express the EDA+ splice variant of fibronectin mRNA, and in HaCaT cells the EDA+/EDA- transcript ratio was elevated compared with normal keratinocytes. Cultured keratinocytes and HaCaT cells showed intracytoplasmic staining with an EDA+ fibronectin-specific antibody and among the positively stained cells many showed mitosis. Using RT-PCR, western blot analysis, and flow cytometry, we showed that in synchronized HaCaT cells the amount of both total fibronectin and its EDA+ isoform change with the proliferation/differentiation state of HaCaT cells and peak in highly proliferating cells. We show that in short-term ex vivo cultures, a small population of EDA+ fibronectin containing cell population appear among psoriatic uninvolved, but not normal epidermal cells. We also demonstrate that cell attachment has a strong influence on the expression of both total and EDA+ fibronectin. Our results suggest that proliferating keratinocytes could be the sources of the psoriasis susceptibility-related EDA+ oncofetal fibronectin in the epidermis.

Plasma transforming growth factor beta1 as a biomarker of psoriasis activity and treatment efficacy

Transforming growth factor-beta(1) (TGFbeta(1)) is thought to be an inhibitor of the keratinocyte hyperproliferation associated with psoriasis. The aim of this study was to evaluate plasma TGFbeta(1) and TGFbeta(2) concentrations in psoriatic patients as possible indicators of treatment efficacy. TGFbeta concentrations were measured in the plasma of 26 patients with psoriasis using an enzyme immunoassay and analysed with respect to the psoriasis area and severity index (PASI) before and after treatment with salicylic acid and/or sulphur followed by dithranol ointment. Baseline plasma concentrations of both TGFbeta(1) and TGFbeta(2) (20.3+/-2.2 ng ml(-1) and 0.14+/-0.02 ng ml(-1), respectively) did not differ significantly from control values (18.3+/-1.6 ng ml(-1) and 0.14+/-0.03 ng ml(-1), respectively). However, a significant positive correlation (r=0.69) between the baseline PASI and TGFbeta(1), but not TGFbeta(2), values was demonstrated. The pretreatment TGFbeta(1) concentration in patients with a PASI >/=15 (26.6+/-3.2 ng ml(-1)) was significantly higher than control values. There were no significant elevation of pretreatment TGFbeta(1) concentrations in patients with a PASI<15, or with respect to TGFbeta(2) in both groups. Treatment caused a significant decrease in TGFbeta(1), but only in patients with a PASI>/=15. Patients with baseline TGFbeta(1) concentrations exceeding the mean of the control group had a PASI value that was significantly higher than that of patients with a TGFbeta(1) concentration below the mean of the controls. These results confirmed an association between plasma TGFbeta(1) concentration and psoriasis severity, and demonstrated its normalization during treatment. Measurement of TGFbeta(1) in plasma should be considered as a possible biomarker of psoriasis activity during its management.

Downregulation of TGFbeta isoforms and their receptors contributes to keratinocyte hyperproliferation in psoriasis vulgaris

BACKGROUND

Psoriasis vulgaris is a chronic inflammatory disorder characterized by epidermal hyperproliferation. Transforming growth factor beta (TGFbetas) have a major antiproliferative action in epidermis.

OBJECTIVE

We evaluated the distribution and levels of expression of TGFbeta isoforms and their receptors in psoriatic versus normal skin with the goal of discovering potential alterations in TGFbeta signal transduction associated with psoriasis.

METHODS

Expression of TGFbeta isoforms and their receptors was analyzed in normal and psoriatic skin using immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques. Furthermore, DNA synthesis was measured in normal keratinocytes transfected with a dominant-negative TGFbeta receptor II (TbetaRII) vector that eliminated most of the cytoplasmic TbetaRII domain.

RESULTS

Marked elevations in DNA synthesis, as assessed by BrdU incorporation and proliferating cell nuclear antigen (PCNA) immunoreactivity, were confirmed in psoriatic epithelial cells. Using immunohistochemistry and RT-PCR analysis, expression of TGFbeta2 and 3 was diminished in the psoriatic epidermis as compared with those observed in normal skin. With respect to TGFbeta receptors, expression of TbetaRI and II was markedly decreased in the psoriatic epidermis. In addition, levels of Smad2 mRNA were also decreased in psoriatic skin. Transfection of normal keratinocytes with the dominant-negative TbetaRII vector significantly elevated DNA synthesis as compared with keratincoytes transfected with control vector (under condition of TGFbeta addition), suggesting that the dominant-negative TbetaRII mutant inhibits the antiproliferative effects of TGFbeta.

CONCLUSION

The present investigation strongly suggest that the TGFbeta signaling pathway is downregulated in psoriatic skin and this situation leads to abnormal cell proliferation due to a functional decrease in growth regulation.

Differential expression of transforming growth factors-β1, -β2, -β3 and the type I, II, III receptors in the lining epithelia of inflamed gingiva

AIMS

To investigate the distribution of transforming growth factor-beta isoforms in chronically inflamed periodontal tissues.

METHODS

The present study determined, by immunohistochemistry, the expression patterns of TGF-betas and their receptors in the lining epithelia of inflamed gingiva. Frozen sections were obtained from 22 human gingival biopsies.

RESULTS

TGF-beta 1 was not detected in gingival epithelial cells in examined sections. Detection of TGF-beta 2 indicated a progressive reduction of staining from the external oral epithelium through to gingival sulcus and the gingival attachment or pocket epithelium. TGF-beta 3 showed intense staining in all domains of both minimally inflamed gingiva and advanced periodontitis tissues. TGF-beta RI was visualised as focal staining of the spinous layer in the external oral epithelium of both periodontitis lesions and minimally inflamed tissues. TGF-beta RII was present throughout the strata, but with progressive reduction in intensity from the oral epithelium to gingival attachment or pocket epithelium respectively while, conversely, TGF-beta RIII showed an increase in diffuse staining intensity from external oral epithelium to pocket epithelium.

CONCLUSIONS

A distinct expression profile was observed within different individuals for TGF-betas and the corresponding receptors. These findings provide a basis for evaluation of the role of these growth factors in the pathogenesis of periodontitis.

Association between psoriasis severity and transforming growth factor beta(1) and beta (2) in plasma and scales from psoriatic lesions

Psoriasis is an inflammatory skin disorder with hyperproliferation of keratinocytes, that can be the result of insufficient inhibitory effect of transforming growth factors-beta (TGF-beta). The aim of this study was to evaluate an association between TGF-beta(1) and -beta(2) in plasma or scales from psoriatic lesions and the severity of the disease. TGF-beta concentrations were measured with an enzyme immunoassay in 41 patients with psoriasis. The mean plasma concentrations of TGF-beta(1) and TGF-beta(2) in patients were: 15.7 +/- 1.4 and 0.15 +/- 0.02 ng/ml respectively. It was also detectable in scales and varied from 24 to 1159 and from 0 to 2.95 pg/mg protein respectively. Plasma TGF-beta(1) correlated significantly with psoriasis area and severity index (PASI). Significant correlation was also demonstrated between TGF-beta(1) concentration in scales and sedimentation rate or the disease duration. There were no correlation between PASI and plasma TGF-beta(2), scales TGF-beta(1) and TGF-beta(2). The highest mean concentration of TGF-beta(1) in scales of patients with mild form of the disease (203 +/- 65 pg/mg protein) and the lowest in severe form (147 +/- 54 pg/mg protein) have been shown. These findings demonstrated association between PASI and plasma levels of TGF-beta(1), that should be considered as a possible indicator of psoriasis activity.

Potential role of the chemokine receptors CXCR3, CCR4, and the integrin alphaEbeta7 in the pathogenesis of psoriasis vulgaris

Various adhesion molecules have been implicated in T lymphocyte binding to dermal vascular endothelium in psoriasis vulgaris, but the chemotactic signals that promote subsequent homing into the adjacent dermis and overlying epidermis are poorly defined. We studied chemokine receptor (CCR1-CCR5, CXCR1-CXCR3), chemokine (interferon-gamma inducible protein 10 [IP-10]), monokine induced by interferon-gamma (MIG), thymus and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC), and adhesion molecule (cutaneous lymphocyte antigen [CLA], E-selectin, lymphocyte function-associated antigen-1 [LFA-1], intercellular adhesion molecule-1 [ICAM-1], very late antigen 4 [VLA-4], vascular cell adhesion molecule-1 [VCAM-1], alphaEbeta7, and E-cadherin) expression in psoriasis by immunohistology, flow cytometry, and molecular techniques. CXCR3 and CCR4 were expressed by dermal CD3+ lymphocytes, and their chemokine ligands, IP-10, MIG, TARC, and MDC, were up-regulated in psoriatic lesions. Keratinocytes stimulated with tumor necrosis factor-alpha and interferon-gamma up-regulated expression of IP-10, MIG, and MDC mRNA, whereas dermal endothelial cells, similarly stimulated, up-regulated expression of IP-10, MDC, and TARC mRNA, suggesting that these cell types were sources of the chemokines detected in biopsies. There was enhanced expression of E-selectin, CLA, LFA-1, ICAM-1, VLA-4, VCAM-1, and alphaEbeta7 in psoriatic lesions versus nonlesional skin. Finally, intra-epidermal CLA+ and alphaEbeta7+ T lymphocytes selectively expressed the chemokine receptor CXCR3. Collectively, these data suggest that CXCR3 and CCR4 may be involved in T lymphocyte trafficking to the psoriatic dermis and that CXCR3 is selectively involved in subsequent T cell homing to the overlying epidermis.

Dermal fibroblasts are one of the therapeutic targets for topical application of 1alpha,25-dihydroxyvitamin D3: the possible involvement of transforming growth factor-beta induction

BACKGROUND

Transforming growth factor (TGF) -beta has been suggested to be an effective inhibitor for abnormal keratinocyte growth in psoriasis. As a majority of the secreted TGF-beta are biologically latent complexes, activation is essential for TGF-beta-mediated cellular responses in vitro and in vivo. Objectives Here we report the response of the TGF-beta regulation system to 1alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3], an active vitamin D3 analogue Patients/methods We studied two types of fibroblasts derived from normal and psoriatic lesional skin, using an enzyme-linked immunosorbent assay and Northern blotting techniques.

RESULTS

1,25(OH)2D3 caused a dose-dependent induction of latent and active TGF-beta1 proteins in both cell cultures. The increases were significant over 72 h, but not within 48 h after stimulation. The time course of TGF-beta1 mRNA expression showed a biphasic response consisting of early ( approximately 1 h) and late phases ( approximately 96 h) of induction. Concomitant increases of TGF-beta2 and -beta3, other mammalian isoforms, were observed in the 1,25(OH)2D3-treated cells, but the kinetics were all different. Co-incubation with metabolic inhibitors, actinomycin D and cycloheximide, revealed that the early induction of TGF-beta1 mRNA by 1,25(OH)2D3 is dependent on de novo RNA synthesis, but not on RNA stabilization or protein synthesis. It seems likely to be a transient and negligible response given the absence of TGF-beta1 protein production. The late induction of TGF-beta1 mRNA was partially blocked by adding isoform-specific antibodies to TGF-beta1, -beta2 and -beta3, indicating TGF-beta autoregulation. Despite these marked responses, there were no significant differences in the TGF-beta expression between normal and psoriatic fibroblasts.

CONCLUSIONS

These results suggest that antiproliferative and anti-inflammatory effects of 1,25(OH)2D3 on psoriatic lesional skin may be mediated, at least in part, by a complex TGF-beta regulation in local dermal fibroblasts.

TGF-beta receptor expression on human keratinocytes: a 150 kDa GPI-anchored TGF-beta1 binding protein forms a heteromeric complex with type I and type II receptors

Keratinocytes play a critical role in re-epithelialization during wound healing, and alterations in keratinocyte proliferation and function are associated with the development of various skin diseases. Although it is well documented that TGF-beta has profound effects on keratinocyte growth and function, there is a paucity of information on the types, isoform specificity and complex formation of TGF-beta receptors on keratinocytes. Here, we report that in addition to the types I, II, and III TGF-beta receptors, early passage adult and neonatal human keratinocytes display a cell surface glycosylphosphatidylinositol (GPI)-anchored 150 kDa TGF-beta1 binding protein. The identities of the four proteins were confirmed on the basis of their affinity for TGF-beta isoforms, immunoprecipitation with specific anti-receptor antibodies, sensitivity to phosphatidylinositol specific phospholipase C and dithiothreitol, and 2-dimensional electrophoresis. Interestingly, the antitype I TGF-beta receptor antibody immunoprecipitated not only the type I receptor, but also the type II receptor and the 150 kDa component, suggesting that the 150 kDa component form heteromeric complexes with the signalling receptors. In addition, two-dimensional (nonreducing/reducing) electrophoresis confirmed the occurrence of a heterotrimeric complex consisting of the 150 kDa TGF-beta1 binding protein, the type II receptor, and the type I receptor. This technique also demonstrated the occurrence of types I and II heterodimers and type I homodimers of TGF-beta receptors on keratinocytes, supporting the heterotetrameric model of TGF-beta signalling proposed using mutant cells and cells transfected to overexpress these receptors. The keratinocytes responded to TGF-beta by markedly downregulating all four TGF-beta binding proteins and by potently inhibiting DNA synthesis. The demonstration that the 150 kDa GPI-anchored TGF-beta1 binding protein forms a heteromeric complex with the TGF-beta signalling receptors suggests that this GPI-anchored protein may modify TGF-beta signalling in human keratinocytes.

Down-regulation of transforming growth factor-beta receptors I and II is seen in lesional but not non-lesional psoriatic epidermis

Transforming growth factor-beta s (TGF-beta s) are a family of growth factors with inhibitory effects on epithelial cell proliferation. Their effects are mediated by two interacting receptors, of which type I (T beta R-I) mediates signal transduction after interaction with type II (T beta R-II) carrying the TGF-beta ligand. We have studied the expression of T beta R-I and T beta R-II in psoriatic and normal human skin by using polyclonal rabbit antisera and immunohistochemistry. Immunohistochemical analysis revealed an intense immunoreactivity for both receptors in the basal and often also suprabasal layer of normal and non-lesional psoriatic epidermis. In contrast, all psoriatic lesions studied lacked detectable immunoreactivity of either receptor in the epidermis. The results suggest that lack of TGF-beta-mediated growth inhibition by down-regulation of TGF-beta receptor expression may play an important part in the pathogenesis of psoriasis.