Transforming growth factor-β1 mediates psoriasis-like lesions via a Smad3-dependent mechanism in mice

Cytokines in psoriasis: From pathogenesis to targeted therapy

Psoriasis is a multifactorial disease that affects 0.84% of the global population and it can be associated with disabling comorbidities. As patients present with thick scaly lesions, psoriasis was long believed to be a disorder of keratinocytes. Psoriasis is now understood to be the outcome of the interaction between immunological and environmental factors in individuals with genetic predisposition. While it was initially thought to be solely mediated by cytokines of type-1 immunity, namely interferon-γ, interleukin-2, and interleukin-12 because it responds very well to cyclosporine, a reversible IL-2 inhibitor; the discovery of Th-17 cells advanced the understanding of the disease and helped the development of biological therapy. This article aims to provide a comprehensive review of the role of cytokines in psoriasis, highlighting areas of controversy and identifying the connection between cytokine imbalance and disease manifestations. It also presents the approved targeted treatments for psoriasis and those currently under investigation.

Differentiation of IL-26+ TH17 intermediates into IL-17A producers via epithelial crosstalk in psoriasis

Interleukin (IL)-26 is a TH17 cytokine with known antimicrobial and pro-inflammatory functions. However, the precise role of IL-26 in the context of pathogenic TH17 responses is unknown. Here we identify a population of blood TH17 intermediates that produce high levels of IL-26 and differentiate into IL-17A-producing TH17 cells upon TGF-β1 exposure. By combining single cell RNA sequencing, TCR sequencing and spatial transcriptomics we show that this process occurs in psoriatic skin. In fact, IL-26+ TH17 intermediates infiltrating psoriatic skin induce TGF-β1 expression in basal keratinocytes and thereby promote their own differentiation into IL-17A-producing cells. Thus, our study identifies IL-26-producing cells as an early differentiation stage of TH17 cells that infiltrates psoriatic skin and controls its own maturation into IL17A-producing TH17 cells, via epithelial crosstalk involving paracrine production of TGF-β1.

The Growth Factor Release from a Platelet-Rich Plasma Preparation Is Influenced by the Onset of Guttate Psoriasis: A Case Report

The involvement of platelets in immune and inflammatory processes is generally recognized; nevertheless, in psoriasis, their role is not clearly understood. We studied the in vitro growth factor release from a platelet-rich plasma preparation, the concentrated growth factors (CGF), in a case of a psoriasis subject three days before the onset of the papule. The CGF clots were incubated in a cell culture medium without growth supplements for 5 h and 1, 3, 6, 7, and 8 days, and the release kinetics of PDGF-AB, VEGF, TNF-α, and TGF-β1 were evaluated. The data, based on the results obtained during the case study, report a general increase in growth factor release in the psoriasis subject with respect to the healthy control, indicating an imbalance of growth factor production from blood cells. Although the results should be validated in the future, they show new aspects of this dermatological pathology, opening new possibilities both as the method of study, using CGF, and the involvement of platelets and growth factors in its development and maintenance.

Indonesian Ciplukan Extract Inhibited TGF-β1/NF-κB Pathway in Experimental Psoriasis Mouse Models

Background:The global prevalence of psoriasis, a chronic inflammatory skin disease, has substantially increased in the last decade. The increase activity of Transforming Growth Factor ß1 (TGFß1)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway which cause inflammation, is the major pathological mechanism in psoriasis. Current psoriasis treatment using chemical agents is hampered by the side-effects when used long-term, which underlines the need for alternative, low side-effect anti-psoriatic agents. The extract of Physalis angulata L., also known as Ciplukan in Indonesia, contains Physalins, compounds known for their anti-inflammatory effects, but whose effect on psoriasis has not been studied. Objective:  This study aimed to investigate the effect of Ciplukan extract (CE) to TGFß1/NF-κB pathway in psoriasis mouse models. Methods: This was experimental study with posttest-only control group design. The CE active ingredients were identified using Liquid chromatography-tandem mass spectrometry (LC-MS/MS). Twenty-five female imiquimod (IMQ) induced psoriasis-like dermatitis mice were allocated into five groups, with three groups receiving 7 days of 400, 800, and 1200 mg/kg bodyweight doses of CE, respectively, and two groups serving as control and IMQ groups. The NF-κB and TGFß1 expressions were evaluated using Allred score based on immunohistochemistry (IHC) staining. Histopathology and clinical psoriasis manifestations were assessed using Baker’s from Hematoxylin Eosin (HE) staining and Psoriasis Area Severity Index (PASI) scores. The Kruskal-Wallis followed by Mann Whitney tests were conducted for data analysis. The p-value < 0.05 was considered to be statistically different.   Results: Based on LC-MS/MS test, Physalin B, D, and F were active ingredients from CE in ethyl acetate solution. An improvement in psoriasis inflammation was observed in 400 and 800 mg/kg bodyweight doses of CE, but only the dosage of 800 mg/kg BW significantly decreased of Allred scores from NF-κB and TGFß1 expressions; Baker’s and PASI scores compared to IMQ group (p<0.05). The 1200 mg/kg bodyweight doses of CE associated with acute toxicity signs and mortality, meanwhile dosage of 800 mg/kg BW showed the highest efficacy with lowest toxicity effect. Conclusions: Ciplukan extract improved psoriasis manifestations via inhibition effect to TGFß1/NF-κB pathway and the extract might be developed as an alternative anti-psoriasis agent

VGLL3 activates inflammatory responses by inducing interleukin-1α secretion

Vestigial-like family member 3 (VGLL3), a member of the vestigial-like family, is a cofactor of the TEA-domain-containing transcription factor (TEAD). Although elevation in VGLL3 expression is associated with inflammatory diseases, such as inflammatory sarcomas and autoimmune diseases, the molecular mechanisms underlying VGLL3-mediated inflammation remain largely unknown. In this study, we analyzed the relationship between elevated VGLL3 expression and the levels of NF-κB, a transcription factor that plays a pivotal role in inflammation. NF-κB was found to be activated in a cell line stably expressing VGLL3. Mechanistically, VGLL3 was shown to promote the expression and secretion of the potent NF-κB-activating cytokine interleukin (IL)-1α, probably through its association with TEADs. As VGLL3 is a target of transforming growth factor β (TGF-β) signaling, we analyzed IL-1α induction upon TGF-β stimulation. TGF-β stimulation was observed to induce IL-1α secretion and NF-κB activation, and VGLL3 was associated with this phenomenon. The TGF-β transcription factors Smad3 and Smad4 were shown to be necessary for inducing VGLL3 and IL-1α expression. Lastly, we found that VGLL3-dependent IL-1α secretion is involved in constitutive NF-κB activation in highly malignant breast cancer cells. Collectively, the findings suggested that VGLL3 expression and TGF-β stimulation activate the inflammatory response by inducing IL-1α secretion.

Analysis of the influence of adalimumab to the expression pattern of mRNA and protein of TGF-β1-3 in dermal fibroblast exposed to lipopolysaccharide

Introduction

Psoriasis is a inflammatory illness, where incorrect expression of cytokines and bacteria lipopolysaccharide are observed. In the therapy of moderate to severe psoriasis anti-TNF drugs, i.e. adalimumab are used which have the influence for secreting another cytokines, such as transforming growth factor-β (TGF-β).

Aim

To analyse the expression profile of mRNA TGF-β1-3 and proteins (TGF-β1 and TGF-β2) it codes in normal human dermal fibroblasts (NHDF) exposed to bacterial lipopolysaccharide (induction of inflammation) and adalimumab (anti-TNF drug).

Material and methods

NHDFs treated with bacterial lipopolysaccharide at a medium concentration of 1 μg/ml for 8 h, and then added to an adalimumab culture at a concentration of 8 μg/ml and continued exposure of the fibroblasts to it for 2, 8 and 24 h. The molecular analysis included microarray, RTqPCR and ELISA assays.

Results

Treating the skin fibroblast cells with LPS resulted in significant statistical changes in the expression of TGF-β1 (↑) and TGF-β2 (↓) in comparison to the control culture. Likewise, after adding adalimumab to the culture of NHDF treated previously with LPS, significant changes in the expression of TGF-β1 (↑) and TGF-β2 (↓) were noted in comparison to the control culture (p < 0.05). On the protein level it can be determined that LPS and adalimumab cause an increase in the concentration of TGF-β1 and a decrease in the expression of TGF-β2 in comparison to the control culture.

Conclusions

Blocking the signalling dependant on TNF-α using adalimumab causes an increase in the expression of TGF-β1 and a simultaneous decrease in the case of TGF-β2.

Natural product topical therapy in mitigating imiquimod-induced psoriasis-like skin inflammation-underscoring the anti-psoriatic potential of Nimbolide

BACKGROUND

Psoriasis is a chronic inflammatory dermatological disorder having complex pathophysiology with autoimmune and genetic factors being the major players. Despite the availability of a gamut of therapeutic strategies, systemic toxicity, poor efficacy, and treatment tolerance due to genetic variability among patients remain the major challenges. This calls for effective intervention with the superior pharmacological profile. Nimbolide (NIM), a major limonoid is an active chemical constituent found in the leaves of the Indian Neem tree, Azadirachta indica. It has gained immense limelight in the past decades for the treatment of various diseases owing to its anti-proliferative, anti-inflammatory, and anti-cancer potentials.

OBJECTIVE

The present study was centered around evaluating the anti-psoriatic effect of NIM in the experimental model of Imiquimod (IMQ)-induced psoriasis-like inflammation model.

MATERIALS AND METHODS

Application of IMQ topically on the dorsum of Balb/c mice from day 0-6 prompted psoriasis-like inflammatory symptoms. Treatment groups included topical administration of NIM incorporated carbopol gel formulation and NIM free drug given through subcutaneous route. Protein expression studies such as immunohistochemistry, Western blotting, and ELISA were employed.

RESULTS

It was clearly observed from our results that NIM significantly ameliorated the expression of inflammatory and proliferation mediators. Further, NIM in the treatment groups significantly improved classic Psoriasis Area Severity Index scoring when compared to IMQ administered group.

CONCLUSION

It is noteworthy that NIM showed a predominant therapeutic effect as compared to other treatment group. To recapitulate, NIM has shown promising activity as an anti-psoriatic agent by remarkably ameliorating inflammation and associated proliferation.

Perspective trends of topical therapy of patients with psoriasis

Topical medications are used to treat not only limited, but also common forms of the disease. Currently prescribed external anti-inflammatory drugs have a low selectivity of action, which does not allow achieving a long-term and pronounced clinical effect without the development of undesirable phenomena. This review presents new options for the use of methotrexate in modern topical forms (AuNPs-3MPS), which make it possible to reduce the incidence of adverse events with a high efficiency of therapy. Shown is an innovative drug that blocks resident memory cells (PAP-1), which will influence the course and relapses of the disease, and possibly even lead to the cure of the patient from psoriasis. A new direction has been described inhibition of serine proteases (ER143, AAN-16) and thus inhibition of IL-36-mediated inflammation, which will allow controlling the inflammatory process in psoriasis in the early stages of its development. In addition, a number of drugs are shown whose action is based on blocking intracellular signaling pathways, which leads to inhibition of the development of the inflammatory response and resolution of psoriatic eruptions: inhibitors of Janus kinases (tofacitinib), transcription factor Stat3 (rS3-PA), secondary messenger of signals (SIS3), phosphodiesterase 7 (ASB16165) and 4 (AN-2728/crisaborol), ROR transcription factor (PF-06763809), phospholipase A2 (AVX001), hydrolases (DZ2002). The results of preclinical and initial stages of clinical trials with an assessment of the safety and tolerability of the studied substances are presented. Based on the review, the advantages and disadvantages of the proposed drugs are characterized. Topical therapy with a selective effect on the key links in the development of psoriasis will increase the effectiveness of treatment and reduce the frequency of unwanted effects.

Ustekinumab therapy changes the transcriptional activity pattern of TGF-β1-3 genes

INTRODUCTION

One of the examples of genes whose expression can be altered by the action of ustekinumab is TGF-β. It is a pleiotropic cytokine whose activity affects psoriatic changes and the state of homeostasis of the whole organism.

AIM

To evaluate the effect of ustekinumab on the transcriptional activity of TGF-β family genes in patients with psoriatic arthritis and to check whether the results obtained can be helpful in monitoring the progress of treatment.

MATERIAL AND METHODS

From total PBMCs obtained from peripheral blood of 14 patients with psoriatic arthritis, total RNA was isolated. The expression level of the TGF-β1, TGF-β2 and TGF-β3 genes was determined by RT-qPCR in real time.

RESULTS

In all the analysed samples, the presence of mRNA of three TGF-β isoforms was quantitated in each week of therapy. TGF-β3 and the smallest TGF-β2 showed the highest expression. Statistically significant correlations were observed in the amount of TGF-β1 and TGF-β3/µg mRNA RNA, TGF-β2 and TGF-β2/µg RNA and TGF-β3 and TGF-β3/µg RNA.

CONCLUSIONS

Ustekinumab influences the transcriptional activity of TGF-β genes, and the changes caused have a bearing on the patient's health.

TGFβ Signaling in Photoaging and UV-Induced Skin Cancer

UVR is a major etiology for premature skin aging that leads to photoaging and UV-induced skin cancers. In the skin, TGFβ signaling is a growth inhibitor for keratinocytes and a profibrotic factor in the dermis. It exerts context-dependent effects on tumor progression. Chronic UV exposure likely causes TGFβ1/SMAD3 signaling activation and contributes to metalloproteinase-induced collagen degradation and photoinflammation in photoaging. UV irradiation also causes gene mutations in key elements of the TGFβ pathway, including TGFβRI, TGFβRII, SMAD2, and SMAD4. These mutations enable tumor cells to escape from TGFβ-induced growth inhibition and induce genomic instability and cancer stem cells, leading to the initiation, progression, invasion, and metastasis of cutaneous squamous cell carcinoma (cSCC). Furthermore, UV-induced mutations cause TGFβ overexpression in the tumor microenvironment (TME) of cSCC, basal cell carcinoma (BCC), and cutaneous melanoma, resulting in inflammation, angiogenesis, cancer-associated fibroblasts, and immune inhibition, supporting cancer survival, immune evasion, and metastasis. The pleiotropic effects of TGFβ provide possible treatment options for photoaging and skin cancer. Given the high UV-induced mutational burden and immune-repressive TME seen in cSCC, BCC, and cutaneous melanoma, treatment with the combination of a TGFβ signaling inhibitor and immune checkpoint blockade could reverse immune evasion to reduce tumor growth.

Transforming Growth Factor-β Signaling in Fibrotic Diseases and Cancer-Associated Fibroblasts

Transforming growth factor-β (TGF-β) signaling is essential in embryo development and maintaining normal homeostasis. Extensive evidence shows that TGF-β activation acts on several cell types, including epithelial cells, fibroblasts, and immune cells, to form a pro-fibrotic environment, ultimately leading to fibrotic diseases. TGF-β is stored in the matrix in a latent form; once activated, it promotes a fibroblast to myofibroblast transition and regulates extracellular matrix (ECM) formation and remodeling in fibrosis. TGF-β signaling can also promote cancer progression through its effects on the tumor microenvironment. In cancer, TGF-β contributes to the generation of cancer-associated fibroblasts (CAFs) that have different molecular and cellular properties from activated or fibrotic fibroblasts. CAFs promote tumor progression and chronic tumor fibrosis via TGF-β signaling. Fibrosis and CAF-mediated cancer progression share several common traits and are closely related. In this review, we consider how TGF-β promotes fibrosis and CAF-mediated cancer progression. We also discuss recent evidence suggesting TGF-β inhibition as a defense against fibrotic disorders or CAF-mediated cancer progression to highlight the potential implications of TGF-β-targeted therapies for fibrosis and cancer.

The Emerging Role of Innate Immunity in Chronic Kidney Diseases

Renal fibrosis is a common fate of chronic kidney diseases. Emerging studies suggest that unsolved inflammation will progressively transit into tissue fibrosis that finally results in an irreversible end-stage renal disease (ESRD). Renal inflammation recruits and activates immunocytes, which largely promotes tissue scarring of the diseased kidney. Importantly, studies have suggested a crucial role of innate immunity in the pathologic basis of kidney diseases. This review provides an update of both clinical and experimental information, focused on how innate immune signaling contributes to renal fibrogenesis. A better understanding of the underlying mechanisms may uncover a novel therapeutic strategy for ESRD.

A novel biphenyl compound IMB-S7 ameliorates hepatic fibrosis in BDL rats by suppressing Sp1-mediated integrin αv expression

Chronic tissue injury with fibrosis results in the disruption of tissue architecture, organ dysfunction, and eventual organ failure. Therefore, the development of effective antifibrotic drugs is urgently required. IMB-S7 is novel biphenyl compound derived from bifendate (biphenyldicarboxylate) that is used for the treatment of chronic hepatitis in China. In the current study we investigated the potential of IMB-S7 as an antihepatic fibrosis agent. In bile duct ligation (BDL) rat model, oral administration of IMB-S7 (400 mg· kg-1· d-1, for 14 days) significantly ameliorated BDL-induced liver necrosis, bile duct proliferation, and collagen accumulation. We then showed that IMB-S7 treatment markedly suppressed the TGF-β/Smad pathway in human hepatic stellate cell line LX2 and mouse primary HSCs, as well as in liver samples of BDL rats, thus inhibiting the transcription of most fibrogenesis-associated genes, including TGF-β1, COL1A1, and ACTA2. Furthermore, IMB-S7 treatment significantly suppressed the expression of integrin αv at the mRNA and protein levels in TGF-β-treated LX2 cells and liver samples of BDL rats. Using integrin αv overexpression and silencing, we demonstrated that integrin αv activity correlated positively with the activation of TGF-β/Smad pathway. Based on dual luciferase assay and DNA affinity precipitation assay, we revealed that IMB-S7 inactivated integrin αv through competitively inhibiting the binding of Sp1, a transcription factor, to the integrin αv (ITGAV) promoter (-173/-163 bp). These results suggest that IMB-S7 inhibits HSCs activation and liver fibrosis through Sp1-integrin αv signaling, and IMB-S7 may be a promising candidate to combat hepatic fibrosis in the future.

Role of TGF-β in Skin Chronic Wounds: A Keratinocyte Perspective

Chronic wounds are characterized for their incapacity to heal within an expected time frame. Potential mechanisms driving this impairment are poorly understood and current hypotheses point to the development of an unbalanced milieu of growth factor and cytokines. Among them, TGF-β is considered to promote the broadest spectrum of effects. Although it is known to contribute to healthy skin homeostasis, the highly context-dependent nature of TGF-β signaling restricts the understanding of its roles in healing and wound chronification. Historically, low TGF-β levels have been suggested as a pattern in chronic wounds. However, a revision of the available evidence in humans indicates that this could constitute a questionable argument. Thus, in chronic wounds, divergences regarding skin tissue compartments seem to be characterized by elevated TGF-β levels only in the epidermis. Understanding how this aspect affects keratinocyte activities and their capacity to re-epithelialize might offer an opportunity to gain comprehensive knowledge of the involvement of TGF-β in chronic wounds. In this review, we compile existing evidence on the roles played by TGF-β during skin wound healing, with special emphasis on keratinocyte responses. Current limitations and future perspectives of TGF-β research in chronic wounds are discussed.

Murine models of psoriasis and its applications in drug development

Psoriasis is an autoimmune skin disease which characteristic of a well-demarcated, erythematous, raised lesion with silvery-white dry scale. Although the mechanism of psoriasis has not been fully understood so far, much progress has been made in understanding many of its complex potential mechanism, particularly the crucial role of the IL-23/Th17 axis. There are a large number of psoriasis models that reflect the complexity of the psoriasis mechanisms. In this review, we summarize various psoriasis mouse models, detail the features and molecular mechanisms of these mouse models, and discuss their strengths and limitations for psoriasis research. The development of mouse models of psoriasis provide an important basis for studying psoriasis pathogenesis and antipsoriatic drugs development. Therefore, the application of various psoriasis mouse models in antipsoriatic drug development are also discussed.

Transient receptor potential ankyrin 1 (TRPA1) positively regulates imiquimod-induced, psoriasiform dermal inflammation in mice

Transient receptor potential ankyrin 1 (TRPA1), a membrane protein ion channel, is known to mediate itch and pain in skin. The function of TRPA1, however, in psoriasiform dermatitis (PsD) is uncertain. Herein, we found that expression of TRPA1 is highly up-regulated in human psoriatic lesional skin. To study the role of TRPA1 in PsD, we assessed Psoriasis Severity Index (PSI) scores, transepidermal water loss (TEWL), skin thickness and pathology, and examined dermal inflammatory infiltrates, Th17-related genes and itch-related genes in c57BL/6 as wild-type (WT) and TRPA1 gene knockout (KO) mice following daily application of topical IMQ cream for 5 days. Compared with WT mice, clinical scores, skin thickness change and TEWL scores were similar on day 3, but were significantly decreased on day 5 in IMQ-treated TRPA1 KO mice (vs WT mice), suggesting reduced inflammation and skin barrier defects. Additionally, the relative area of epidermal Munro's microabscesses and mRNA levels of neutrophil inducible chemokines (S100A8, S100A9 and CXCL1) were decreased in the treated skin of TRPA1 KO mice, suggesting that neutrophil recruitment was impaired in the KO mice. Furthermore, mast cells, CD31⁺ blood vascular cells, CD45⁺ leukocytes and CD3⁺ T cells were all reduced in the treated skin of TRPA1 KO mice. Lastly, mRNA expression levels of IL-1β, IL-6, IL-23, IL-17A, IL-17F and IL-22 were decreased in TRPA1 KO mice. In summary, these results suggest a key role for TRPA1 in psoriasiform inflammation and raising its potential as a target for therapeutic intervention.

Advances in Understanding the Immunological Pathways in Psoriasis

Psoriasis vulgaris is a chronic, immune-mediated, inflammatory, polygenic skin disorder affecting approximately 2% of the population. It has a great impact on quality of life; patients often experience depression, anxiety, stigma as well as suicidal behavior. Even though psoriasis is one of the most studied dermatological conditions, the pathogenesis of the disease is still not completely elucidated. The complex interactions between keratinocytes, dendritic cells, T-lymphocytes, neutrophils and mast cells are responsible for the histopathological changes seen in psoriasis. The pathogenic model leading to the formation of psoriatic plaques has however evolved a lot over the years. There is now enough evidence to support the role of interleukin (IL) -23, IL-17, IL-22, T helper (Th) -17 cells, Th-22 cells, T regulatory cells, transforming growth factor (TGF)-β1 and IL-10 in the pathogenesis of the disease. Moreover, several inflammatory and anti-inflammatory molecules are currently being investigated, some of them showing promising results. The aim of this paper is to look over the most recent advances in the immunological pathways involved in the pathogenesis of psoriasis vulgaris.

Transforming growth factor-β1 gene polymorphism in psoriasis vulgaris

Background

Increased transforming growth factor beta 1 (TGF-β1) in the epidermis and serum has been found in psoriatic patients. The mechanism for this increase remains unclear.

Objective

To study the TGF-β1 gene polymorphism at codon 10 and its relation to psoriasis susceptibility in a sample of Egyptian patients.

Materials and methods

This cross-sectional study involved 70 patients with psoriasis vulgaris and 100 age- and sex- comparable healthy volunteers as a control group. Genomic DNA was prepared from peripheral blood lymphocytes from all subjects using QIAamp DNA mini kit (QIAGEN Inc., Germany). The TGF-β1 polymorphism was genotyped by PCR-based restricted fragment length polymorphism (PCR-RFLP) analysis. Amplification of codon 10, located in exon 1 of TGFβ1 gene was done through PCR reaction using gene-specific primers.

Results

Statistically significant difference was found between psoriasis patient and controls as regards TGF-β1 (T869C) polymorphism (P=0.045). The presence of TT genotype was associated with a 3-fold risk of psoriasis compared to CC genotype (P=0.016, OR: 3.13 95% CI: 1.24–7.88). T allele was significantly more frequent in psoriasis patients (P=0.017). TGF-β1 gene mutation was significantly higher among psoriasis patients with positive family history (P=0.007).

Conclusion

TGF-β1 gene polymorphism at codon 10 (T869C) is significantly associated with susceptibility to psoriasis in Egyptian patients. This polymorphism is more common in patients with a positive family history of psoriasis.

Variances in the mRNA expression profile of TGF-β1-3 isoforms and its TGF-βRI-III receptors during cyclosporin a treatment of psoriatic patients

Introduction

Psoriasis is a chronic, immunologic, multi-factor inflammatory skin disease, strongly associated with a higher level of a number of cytokines, such as isoforms of transforming growth factor β (TGF-β1–3) and its receptors (TGF-βRI–III). One of the most popular and important drugs used to treat this disease is cyclosporin A (CsA).

Aim

The aim of this study was to investigate the expression of genes encoding the transforming growth factor (TGF)-β isoforms and receptors of the cytokine TGF-βRs in psoriatic patients during an 84-day long observation of the effects of cyclosporin A therapy. It made an attempt to determine the usefulness of testing mRNA expression of TGF-β1–3 and its receptors TGF-βRI–III as the supplementary molecular markers of lost sensitivity to the medicine.

Material and methods

The study group consisted of 32 patients with psoriasis (20 men and 12 women) treated with cyclosporin A. The changes in expression patterns of TGF-β1-3 and TGF-βRI-III were performed by real-time quantitative reverse transcription PCR (RTqPCR).

Results

The expression of TGF-β1-3 and TGF-βRI-III were detected in the whole period of therapy with CsA. Changes in transcriptional activities of TGF-β1–3 and TGF-βRI–III during pharmacotherapy were observed. Differences in the expression of these genes were found before and after 42 and 84 days of using CsA.

Conclusions

The changes in expression profiles of TGF-β1-3 and TGF-βRI-III during CsA therapy can be a useful molecular marker of lost sensitivity to the medicine.

Murine models of psoriasis and their usefulness for drug discovery

INTRODUCTION

Psoriasis is an autoimmune skin disease characterized by red plaques with silver or white multilayered scales with a thickened acanthotic epidermis. Using mouse models of cutaneous inflammation, IL-23/Th17 was identified to have a potential key role in psoriasis. New treatments to slow this inflammatory skin disorder are urgently needed. To aid their discovery, a psoriasis animal model mimicking human psoriasis is urgently needed for their early preclinical evaluation. Areas covered: The authors review animal models of psoriasis and analyze the features and molecular mechanisms involved in these mouse models. The application of various mouse models of psoriasis for drug discovery and development has also been reviewed and the possible molecular targets in psoriasis for future anti-psoriatic drug design is discussed. Expert opinion: So far, it has been difficult to create an animal model that exactly simulates a human disease or condition. The xenotransplantation model is regarded as the closest to incorporating the complete genetic, phenotypic, and immunopathogenic processes of psoriasis. However, the imiquimod (IMQ)-induced model is the most prevalent among psoriatic mouse models due to its ease of use, convenience, and low cost. Further efforts to develop psoriasis-like skin models in mice are needed for the study and treatment of this complex disease.

Overexpression of Glucocorticoid-induced Leucine Zipper (GILZ) increases susceptibility to Imiquimod-induced psoriasis and involves cutaneous activation of TGF-β1

Psoriasis vulgaris is a chronic inflammatory skin disease affecting millions of people. Its pathophysiology is complex and involves a skin compartment with epidermal and immune cells which produce cytokines, e.g. belonging to the IL-23–Th17-cell axis. Glucocorticoids (GCs) are the most common therapeutics used in cutaneous inflammatory disorders and GC-induced leucine zipper (GILZ) has emerged as a mediator of GCs due to its anti-inflammatory actions, theoretically lacking GC side-effects. We evaluated whether GILZ may provide a better therapeutic index in comparison to GCs during the onset and progression of psoriasis by generating and characterizing a mouse model with generalized overexpression of this protein (GILZ-Tg mice) and the imiquimod (IMQ) psoriasis model. Unexpectedly, in GILZ-Tg mice, the severity of IMQ-induced psoriasis-like skin lesions as well as induction of cytokines commonly up-regulated in human psoriasis (Il-17, Il-22, Il-23, Il-6, S100a8/a9, and Stat3) was significantly more pronounced relative to GILZ-Wt mice. The increased susceptibility to IMQ-induced psoriasis of GILZ-Tg mice was significantly associated with skin-specific over-activation of TGF-β1-mediated signaling via SMAD2/3. Our findings demonstrate that GILZ may behave as pro-inflammatory protein in certain tissues and that, similar to prolonged GC therapy, GILZ as an alternative treatment for psoriasis may also have adverse effects.

Deletion of Smad3 improves cardiac allograft rejection in mice

T cells play a critical role in acute allograft rejection. TGF-β/Smad3 signaling is a key pathway in regulating T cell development. We report here that Smad3 is a key transcriptional factor of TGF-β signaling that differentially regulates T cell immune responses in a mouse model of cardiac allograft rejection in which donor hearts from BALB/c mice were transplanted into Smad3 knockout (KO) and wild type (WT) mice. Results showed that the cardiac allograft survival was prolonged in Smad3 KO recipients. This allograft protection was associated with a significant inhibition of proinflammatory cytokines (IL-1β, TNF-α, and MCP-1) and infiltration of neutrophils, CD3⁺ T cells, and F4/80⁺ macrophages. Importantly, deletion of Smad3 markedly suppressed T-bet and IFN-γ while enhancing GATA3 and IL-4 expression, resulting in a shift from the Th1 to Th2 immune responses. Furthermore, mice lacking Smad3 were also protected from the Th17-mediated cardiac injury, although the regulatory T cell (Treg) response was also suppressed. In conclusion, Smad3 is an immune regulator in T cell-mediated cardiac allograft rejection. Loss of Smad3 results in a shift from Th1 to Th2 but suppressing Th17 immune responses. Thus, modulation of TGF-β/Smad3 signaling may be a novel therapy for acute allograft rejection.

Association of down-regulation of CD109 expression with up-expression of Smad7 in pathogenesis of psoriasis

Transforming growth factor (TGF)-β signaling plays an important role in the pathogenesis of psoriasis. CD109, a novel TGF-β co-receptor, which inhibits TGF-β signaling by enhancing Smad7-dependent degradation of TGF-β type I receptor (TGF-β RI), is abnormally expressed in psoriasis. To date, the expression of Smad7 and the correlation between CD109 and Smad7 expression in psoriasis have not been fully elucidated. This study was designed to investigate the expression and the correlation of CD109 and TGF-β signaling associated proteins in psoriasis and their roles in the pathogenesis of psoriasis. Thirty-two psoriasis specimens were subjected to immunohistochemical staining for CD109, Smad7, TGF-β RI and Ki67. Ten normal skin (NS) specimens served as controls. The positive expression rate (% positive cells) of Smad7 and Ki67 in psoriasis was significantly higher than in NS (62.6%±19.9% vs. 17.2%±4.4%, and 50.7%±14.3% vs. 19.5%±3.2%, respectively, P<0.001), and the expression levels of CD109 and TGF-β RI were reduced significantly in psoriasis as compared with NS (8.1%±6.7% vs. 35.8%±6.7% and 27.3%±3.4% vs. 3.0%±3.4%, respectively, P<0.001). There were significantly negative correlations between CD109 and Smad7 (r=-0.831, P<0.01). These findings indicated that CD109 might play a certain role in the pathogenesis of psoriasis. Lower expression of CD109 and TGF-β RI was highly correlated with higher expression of Smad7 and Ki67, suggesting that CD109 may induce the pathogenesis of psoriasis through Smad7-mediated degradation of TGF-β RI, and lead to the termination of TGF-β signaling.

Directing immunomodulation using biomaterials for endogenous regeneration

Stem cell therapy and tissue engineering hold considerable potential for innovative and transformative strategies to repair damaged tissue form and function. Although many approaches are adopting ex vivo expanded cells for transplantation, an alternative is to manipulate the biomaterial-host interactions that recruit the patients' own stem cells endogenously for regeneration. There are several considerations in targeting the biomaterial-host interactions therapeutically, not the least of which is the biomimetic design of extracellular matrix (ECM)-mimicking materials and the administration of navigation cues and small molecules that target specific aspects of the native healing cascades to stimulate homing of endogenous stem cells and, thereafter, their expansion and differentiation. A sequence of coordinated interactions between the local niche cells and implanted biomaterials offers signals and sign posts that may instruct the cells traveling toward the injured tissues. Furthermore, stem cell function is critically influenced by extrinsic signals provided by the niche as well as by the implanted biomaterials. Novel strategies harnessing growth factors and immunological cues to design materials not only can modulate the behavior of stem cells but also can alter innate and adaptive immunity in a controlled manner. We envisage that successful and safe endogenous regeneration will involve at least three aspects, i.e., homing of sufficient stem cells, controlling cell fate determination, and blunting host immune responses to outside biomaterial devices. Improving our understanding of the biological and physicochemical signals of biomimetic biomaterials that govern immunomodulation for in situ tissue regeneration, particularly context-dependent macrophage (Mφ) polarization, will lead to a concurrent improvement in clinical outcomes.

Endofin, a novel BMP-SMAD regulator of the iron-regulatory hormone, hepcidin

BMP-SMAD signalling plays a crucial role in numerous biological processes including embryonic development and iron homeostasis. Dysregulation of the iron-regulatory hormone hepcidin is associated with many clinical iron-related disorders. We hypothesised that molecules which mediate BMP-SMAD signalling play important roles in the regulation of iron homeostasis and variants in these proteins may be potential genetic modifiers of iron-related diseases. We examined the role of endofin, a SMAD anchor, and show that knockdown of endofin in liver cells inhibits basal and BMP-induced hepcidin expression along with other BMP-regulated genes, ID1 and SMAD7. We show for the first time, the in situ interaction of endofin with SMAD proteins and significantly reduced SMAD phosphorylation with endofin knockdown, suggesting that endofin modulates hepcidin through BMP-SMAD signalling. Characterisation of naturally occurring SNPs show that mutations in the conserved FYVE domain result in mislocalisation of endofin, potentially affecting downstream signalling and modulating hepcidin expression. In conclusion, we have identified a hitherto unrecognised link, endofin, between the BMP-SMAD signalling pathway, and the regulation of hepcidin expression and iron homeostasis. This study further defines the molecular network involved in iron regulation and provides potential targets for the treatment of iron-related disorders.