Keratinocyte apoptosis and p53 expression in cutaneous lupus and dermatomyositis

Identification of Latent Diagnostic Biomarkers and Biological Pathways in Dermatomyositis Based on WGCNA

Introduction

Dermatomyositis (DM) is a chronic autoimmune disease of predominantly lymphocytic infiltration mainly involving the transverse muscle. Its pathogenesis is remaining unknown. This research is designed to probe the latent pathogenesis of dermatomyositis, identify potential biomarkers, and reveal the pathogenesis of dermatomyositis through information biology analysis of gene chips.

Methods

In this study, we utilised the GSE14287 and GSE11971 datasets rooted in the Gene Expression Omnibus (GEO) databank, which included a total of 62 DM samples and 9 normal samples. The datasets were combined, and the differentially expressed gene sets were subjected to weighted gene coexpression network analysis, and the hub gene was screened using a protein interaction network from genes in modules highly correlated with dermatomyositis progression.

Results

A total of 3 key genes-myxovirus resistance-2 (MX2), oligoadenylate synthetase 1 (OAS1), and oligoadenylate synthetase 2 (OAS2)-were identified in combination with cell line samples, and the expressions of the 3 genes were verified separately. The results showed that MX2, OAS1, and OAS2 were highly expressed in LPS-treated cell lines compared to normal cell lines. The results of pathway enrichment analysis of the genes indicated that all 3 genes were enriched in the cytosolic DNA signalling and cytokine and cytokine receptor interaction signalling pathways; the results of functional enrichment analysis showed that all 3 were enriched in interferon-α response and interferon-γ response functions.

Conclusions

This is important for the study of the pathogenesis and objective treatment of dermatomyositis and provides important reference information for the targeted therapy of dermatomyositis.

Role of Hair Transplantation in Scarring Alopecia-To Do or Not to Do

Alopecia in the scalp region leads to psychosocial embarrassment for an individual. Alopecia could be due to several reasons, including genetic, hormonal, traumatic and infections. Cicatricial alopecias (CAs) are considered as trichological emergency, since their progression is rapid and always results in permanent hair loss. The pathogenesis, disease progression and prognosis of CA are poorly understood, and the treatment process is still evolving. An early diagnosis must be established, and aggressive treatment protocol should be followed in the management of scarring alopecia. This article presents various aspects of CA and determines whether hair transplant (HT) should be done in this condition.

Lupus band test can be used in combination with anti-chromatin antibodies and complement analysis to predict transition from cutaneous to systemic lupus

The lupus band test (LBT) is frequently performed for patients with lupus erythematosus (LE) but its capacity to discriminate cutaneous (C)LE from systemic (S)LE is debated, as well as its association with serum antinuclear antibodies (ANA) and complement reduction. Among 158 patients, 56 received retrospectively a diagnosis of CLE, 37 have SLE and 65 other skin disorders. Considering 29 clinical, histopathologic, LBT, and serological parameters: 5 parameters were effective in distinguishing LE from other skin disorders (e.g. skin photosensitivity, LBT positivity, basal vacuolar changes, thickening of the basement membrane, and anti-SSA-60 kDa); and 8 parameters were able to separate SLE from CLE (e.g. arthritis, lupus nephritis, hematological manifestations, Raynaud/sicca manifestations, anti-chromatin, anti-dsDNA, and low levels of C3/4). A positive LBT was further determined to be associated with systemic manifestations when associated with anti-chromatin response and complement reduction in the profile of patients evolving to a systemic form of lupus.

Mechanisms of Photosensitivity in Autoimmunity

Aberrant responses to UV light frequently lead to the formation of skin lesions and the activation of systemic inflammation in some autoimmune diseases, especially systemic lupus erythematosus. Whereas the effects of UV light on the skin have been studied for decades, only recently have some of the mechanisms that contribute to abnormal responses to UV light in patients with autoimmune diseases been uncovered. This review will discuss the biology of UV in the epidermis and discuss the abnormal epidermal and inflammatory mechanisms that contribute to photosensitivity. Further research is required to fully understand how to normalize UV-mediated inflammation in patients with autoimmune diseases.

Expression of the OAS Gene Family Is Highly Modulated in Subjects Affected by Juvenile Dermatomyositis, Resembling an Immune Response to a dsRNA Virus Infection

Background: Juvenile dermatomyositis (JDM) is a systemic, autoimmune, interferon (IFN)-mediated inflammatory muscle disorder that affects children younger than 18 years of age. JDM primarily affects the skin and the skeletal muscles. Interestingly, the role of viral infections has been hypothesized. Mammalian 2′-5′-oligoadenylate synthetase (OAS) genes have been thoroughly characterized as components of the IFN-induced antiviral system, and they are connected to several innate immune-activated diseases. The main purpose of the paper is to define the potential interrelationship between the OAS gene family network and the molecular events that characterize JDM along with double-stranded RNA (dsRNA) molecular pathways. Methods: We analyzed three microarray datasets obtained from the NCBI in order to verify the expression levels of the OAS gene family network in muscle biopsies (MBx) of JDM patients compared to healthy controls. Furthermore, From GSE51392, we decided to select significant gene expression profiles of primary nasal and bronchial epithelial cells isolated from healthy subjects and treated with polyinosinic-polycytidylic acid (poly(I:C)), a synthetic analog of double-stranded RNA (dsRNA), a molecular pattern associated with viral infection. Results: The analysis showed that all OAS genes were modulated in JDM muscle biopsies. Furthermore, 99% of OASs gene family networks were significantly upregulated. Of importance, 39.9% of modulated genes in JDM overlapped with those of primary epithelial cells treated with poly(I:C). Moreover, the microarray analysis showed that the double-stranded dsRNA virus gene network was highly expressed. In addition, we showed that the innate/adaptive immunity markers were significantly expressed in JDM muscles biopsies. and that their levels were positively correlated to OAS gene family expression. Conclusion: OAS gene expression is extremely modulated in JDM as well as in the dsRNA viral gene network. These data lead us to speculate on the potential involvement of a viral infection as a trigger moment for this systemic autoimmune disease. Further in vitro and translational studies are needed to verify this hypothesis in order to strategically plan treatment interventions.

Primary Scarring Alopecia: Clinical-Pathological Review of 72 Cases and Review of the Literature

PURPOSE OF THE STUDY

To analyze the epidemiologic, demographic, clinical, and histological characteristics of primary scarring alopecia (PSA) cases diagnosed over a 7-year period at the Department of Dermatology, Hospital Clinic, Barcelona, Spain.

PROCEDURES

Seventy-two patients diagnosed with PSA between 2006 and 2012 were included. Age, sex, ethnic group, clinical pattern, predominant histological infiltrate, final clinical diagnosis, time of onset, treatments used, and clinical evolution were evaluated and correlated.

RESULTS

The ethnic groups were distributed as follows: 93% European-Caucasian, 5% Mestizo-American, 1% oriental, and 1% Afro-American. Most cases were females (71%), and mean age was 51 ± 6 years. The follicular pattern was the most common, and the predominant inflammatory infiltrate was lymphocytic. Lichen planopilaris and frontal fibrosing alopecia were the main diagnoses. When correlating clinical aspects and histopathology, lymphocytic PSAs had a subacute onset and resulted in a nonchanging, more stable form, while neutrophilic PSAs had a more acute onset with an evolution of acute outbreaks. PSAs in a late stage with an absent/mild infiltrate had a subclinical onset and a slowly progressive or stable evolution.

CONCLUSIONS

The PSAs are severe trichological conditions. Their high clinical and histopathological variability make them a diagnostic and therapeutic challenge.

MESSAGE OF THE PAPER

Knowing the clinical and histopathological aspects of PSAs should be of crucial importance to the dermatologist.

Antimalarial lichenoid tissue reactions in patients with pre-existing lupus erythematosus

Recently a number of cases of drug induction or exacerbation of lupus erythematosus (LE) specific skin disease have been described in the literature. Many of the responsible medications are also known for their ability to induce a lichenoid tissue reaction. Aminoquinoline antimalarials are currently the first line of therapy in cutaneous LE specific skin disease. Lichenoid tissue reactions are among the most common cutaneous side effects of aminoquinolone antimalarials. We report three cases of aminoquinolone antimalarial induced or exacerbated LE specific skin disease. We also review the pathophysiology of LE specific skin disease and propose a mechanism by which induction of the lichenoid tissue reaction may result in Koebnerization of LE specific skin lesions.

Photoaggravated disorders

Photoaggravated skin disorders are diseases that occur without UV radiation but are sometimes or frequently exacerbated by UV radiation. In conditions, such as lupus erythematosus, photoaggravation occurs in a majority of patients, whereas in conditions, such as psoriasis and atopic dermatitis, only a subset of patients demonstrate photoaggravation. Polymorphous light eruption is a common photodermatosis in all skin types, making it important to differentiate photoaggravation of an underlying disorder, such as lupus erythematosus, from superimposed polymorphous light eruption. Disease-specific treatments should be instituted where possible. A key component of management of photoaggravated conditions is photoprotection with behavioral change, UV-protective clothing, and broad-spectrum sunscreen.

Abnormally differentiating keratinocytes in the epidermis of systemic sclerosis patients show enhanced secretion of CCN2 and S100A9

Skin involvement with dermal fibrosis is a hallmark of systemic sclerosis (SSc), and keratinocytes may be critical regulators of fibroblast function through secretion of chemo-attracting agents, as well as through growth factors and cytokines influencing the phenotype and proliferation rate of fibroblasts. Epithelial-fibroblast interactions have an important role in fibrosis in general. We have characterized the SSc epidermis and asked whether SSc-injured epidermal cells release factors capable of promoting fibrosis. Our results show that the SSc epidermis is hypertrophic, and has altered expression of terminal differentiation markers involucrin, loricrin, and filaggrin. Multiplex profiling revealed that SSc epidermal explants release increased levels of CCN2 and S100A9. CCN2 induction was found to spread into the upper papillary dermis, whereas S100A9 was shown to induce fibroblast proliferation and to enhance fibroblast CCN2 expression via Toll-like receptor 4. These data suggest that the SSc epidermis provides an important source of pro-fibrotic CCN2 and proinflammatory S100A9 in SSc skin, and therefore contributes to the fibrosis and inflammation seen in the disease.

Primary cicatricial alopecia: recent advances in understanding and management

Primary cicatricial alopecias (PCA) are a rare group of disorders, in which the hair follicle is the main target of destructive inflammation resulting in irreversible hair loss with scarring of affected lesions. The most typical clinical manifestation of PCA is the loss of visible follicular ostia. The histopathological hallmark of a fully developed lesion is the replacement of the hair follicle structure by fibrous tissue. PCA could share similar clinical manifestations and eventually lead to "burn-out" alopecia. Some subsets are hardly distinguishable histopathologically and the mechanisms that elicit such a destructive reaction have not been fully elucidated. Thus, the management of PCA represents one of the most challenging clinical problems for dermatologists. The aim of this review is to provide a concise and comprehensive summary of recent advances in PCA management, especially focusing on novel methodologies to aid diagnosis, and updates on our understanding of the etiopathogenesis. Dermoscopy, a new pathological preparation technique and direct immunofluorescence analysis enable more accurate clinicopathological diagnosis of PCA. Microarray analysis may be beneficial to distinguish PCA subtypes. Currently suggested mechanisms underlying PCA include loss of immune protection of stem cells, impaired stem cell self-maintenance, enhanced autoimmunity by pro-inflammatory cytokines and environmental/genetic predispositions. Interestingly, recent data indicates the association between lipid metabolism dysregulation and PCA development, implying an important role of the sebaceous gland dysfunction in the etiopathogenesis. Based on that hypothesis and observations, novel therapeutic approaches have been proposed, including the use of peroxisome proliferator-activated receptor-γ agonist for lichen planopilaris.

Current and emerging strategies for the treatment and management of systemic lupus erythematosus based on molecular signatures of acute and chronic inflammation

Lupus is a chronic, systemic inflammatory condition in which eicosanoids, cytokines, nitric oxide (NO), a deranged immune system, and genetics play a significant role. Our studies revealed that an imbalance in the pro- and antioxidants and NO and an alteration in the metabolism of essential fatty acids exist in lupus. The current strategy of management includes administration of nonsteroidal anti-inflammatory drugs such as hydroxychloroquine and immunosuppressive drugs such as corticosteroids. Investigational drugs include the following: 1) belimumab, a fully human monoclonal antibody that specifically recognizes and inhibits the biological activity of B-lymphocyte stimulator, also known as B-cell-activation factor of the TNF family; 2) stem cell transplantation; 3) rituximab, a chimeric monoclonal antibody against CD20, which is primarily found on the surface of B-cells and can therefore destroy B-cells; and 4) IL-27, which has potent anti-inflammatory actions. Our studies showed that a regimen of corticosteroids and cyclophosphamide, and methods designed to enhance endothelial NO synthesis and augment antioxidant defenses, led to induction of long-lasting remission of the disease. These results suggest that methods designed to modulate molecular signatures of the disease process and suppress inflammation could be of significant benefit in lupus. Some of these strategies could be vagal nerve stimulation, glucose-insulin infusion, and administration of lipoxins, resolvins, protectins, and nitrolipids by themselves or their stable synthetic analogs that are known to suppress inflammation and help in the resolution and healing of the inflammation-induced damage. These strategies are likely to be useful not only in lupus but also in other conditions, such as rheumatoid arthritis, scleroderma, ischemia-reperfusion injury to the myocardium, ischemic heart disease, and sepsis.

The pathogenesis of primary cicatricial alopecias

Cicatricial (scarring) alopecia results from irreversible damage to epithelial stem cells located in the bulge region of the hair follicle, generally as a result of inflammatory mechanisms (eg, in the context of autoimmune disease). In primary cicactricial alopecia (PCA), the hair follicle itself is the key target of autoaggressive immunity. This group of permanent hair loss disorders can be classified into distinct subgroups, characterized by the predominant peri-follicular inflammatory cell type. In none of these PCA forms do we know exactly why hair follicles begin to attract such an infiltrate. Thus, it is not surprising that halting or even reversing this inflammation in PCA is often extremely difficult. However, increasing evidence suggests that healthy hair follicle epithelial stem cells enjoy relative protection from inflammatory assault by being located in an immunologically "privileged" niche. Because this protection may collapse in PCA, one key challenge in PCA research is to identify the specific signaling pathways that endanger, or restore, the relative immunoprotection of these stem cells. After a summary of pathobiological principles that underlie the development and clinical phenotype of PCA, we close by defining key open questions that need to be answered if more effective treatment modalities for this therapeutically very frustrating, but biologically fascinating, group of diseases are to be developed.

Dermatomyositis

Dermatomyositis (DM) is a chronic inflammatory disorder of the skin and muscles. Although thought to be autoimmune in origin, many questions remain as to the etiopathogenesis of this disease. DM has classically been considered a humorally mediated disease. Current evidence, however, seems to increasingly support alternative (though not mutually exclusive) mechanisms of pathogenesis, including cell-mediated and innate immune system dysfunction. Pathologic findings of DM in muscle include infarcts, perifascicular atrophy, endothelial cell swelling and necrosis, vessel wall membrane attack complex deposition, and myocyte-specific MHC I upregulation. As for the skin, histopathologic findings include hyperkeratosis, epidermal basal cell vacuolar degeneration and apoptosis, increased dermal mucin deposition, and a cell-poor interface dermatitis. Autoantibodies, particularly those that bind nuclear or cytoplasmic ribonucleoprotein antigens, are also commonly found in DM, although their importance in pathogenesis remains unclear. Defective cellular clearance, genetic predilection and environmental exposures, such as viral infection, may also play an important role in the pathogenesis of DM. The seminal work regarding the pathogenesis of DM is reviewed and an update on the recent basic and molecular advances in the field is provided.

Ultraviolet light and cutaneous lupus

Exposure to ultraviolet (UV) light is one of the major factors known to trigger cutaneous disease activity in (systemic) lupus erythematosus patients. UV light, UVB in particular, is a potent inducer of apoptosis. Currently, disturbed clearance of apoptotic cells is one of the concepts explaining the development of inflammation in lupus patients. We review the role of apoptotic cells and autoantibodies in the pathogenesis of UVB induced skin lesions.

A Central Role of Nucleosomes in Lupus Nephritis

Lupus nephritis is characterized by the presence of subendothelial and subepithelial immune complexes and thickening of the glomerular basement membranes (GBM). Electron-dense structures (EDS) in mesangium and GBM have been demonstrated to constitute target structures for nephritogenic autoantibodies in vivo. Whether these antibodies bind nucleosomal antigens within the EDS or cross-react with components of the GBM has not been resolved. Data recently published point at intra-GBM-associated nucleosomes as target for the nephritogenic autoantibodies. Colocalization IEM has demonstrated that autoantibodies and experimental antibodies against DNA, histones, or transcription factors like TATA box-binding protein colocalize in the EDS. By using terminal transferase in situ nick-end labeling in combination with immune electron microscopy to detect DNA specifically in human and murine SLE kidneys, we were able to detect DNA within the EDS of nephritic glomeruli that corresponded with the detected autoantibodies.

Lupus erythematosus and other autoimmune diseases related to statin therapy: a systematic review

BACKGROUND

Statins have been increasingly associated with drug-induced autoimmune reactions, including lupus erythematosus.

OBJECTIVE

To identify and determine the clinical and biological characteristics of statin-induced autoimmune reactions.

MATERIAL AND METHODS

The MEDLINE database (1966 to September 2005) was used to identify all reported cases of statin-induced autoimmune diseases. The keywords used were statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, adverse effects, autoimmune disease, lupus erythematosus, dermatomyositis and polymyositis.

RESULTS

Twenty-eight cases of statin-induced autoimmune diseases have been published so far. Systemic lupus erythematosus was reported in 10 cases, subacute cutaneous lupus erythematosus in three cases, dermatomyositis and polymyositis in 14 cases and lichen planus pemphigoides in one case. Autoimmune hepatitis was observed in two patients with systemic lupus erythematosus. The mean time of exposure before disease onset was 12.8+/-18 months; range 1 month-6 years. Systemic immunosuppressive therapy was required in the majority of cases. In many patients, antinuclear antibodies were still positive many months after clinical recovery. A lethal outcome has been recorded in two patients despite aggressive immunosuppressive therapy.

CONCLUSION

Long-term exposure to statins may be associated with drug-induced lupus erythematosus and other autoimmune disorders. Fatal cases have been reported despite early drug discontinuation and aggressive systemic immunosuppressive therapy.

Anti-p53 antibodies in patients with dermatomyositis/polymyositis

Dermatomyositis/polymyositis (DM/PM), which is often accompanied by various immunological abnormalities, was reported to be associated with an increased incidence of malignancies. In this study, we analyzed serum levels of anti-p53 antibody (anti-p53 Ab) in DM/PM patients and in normal controls. Serum levels of anti-p53 Abs were significantly higher in DM/PM patients than those in healthy controls. However, there was no significant difference between serum levels in patients with malignancies and those in patients without malignancies. Anti-p53 Abs were positive in 13% (4 out of 31) of the DM/PM patients. Of these four patients, only one had an internal malignancy. Immunoglobulin G levels were significantly higher in patients positive for anti-p53 Ab than those who were not. These results seemed to suggest that the presence of anti-p53 Abs in DM/PM patients is due to immunological abnormalities in this disease.

A New Approach to Managing Oral Manifestations of Sjogren's Syndrome and Skin Manifestations of Lupus

Sjogren's syndrome (SS) is an autoimmune disorder that affects the salivary glands, leading to xerostomia, and the lacrimal glands, resulting in xerophthalmia. Secondary SS is associated with other autoimmune disorders such as systemic rheumatic diseases and systemic lupus erythematosis (SLE), which can affect multiple organs, including the epidermis. Recent studies have demonstrated that green tea polyphenols (GTPs) possess both anti-inflammatory and anti-apoptotic properties in normal human cells. Epidemiological evidence has indicated that, in comparison to the United States, the incidence of SS, clinical xerostomia and lupus is considerably lower in China and Japan, the two leading green tea-consuming countries.Thus, GTPs might be responsible, in part, for geographical differences in the incidence of xerostomia by reducing the initiation or severity of SS and lupus. Consistent with this, molecular, cellular and animal studies indicate that GTPs could provide protective effects against autoimmune reactions in salivary glands and skin. Therefore, salivary tissues and epidermal keratinocytes could be primary targets for novel therapies using GTPs. This review article evaluates the currently available research data on GTPs, focusing on their potential application in the treatment of the oral manifestations of SS and skin manifestations of SLE.

Accumulation of apoptotic cells in the epidermis of patients with cutaneous lupus erythematosus after ultraviolet irradiation

OBJECTIVE

To examine whether apoptosis contributes to the pathogenesis of skin lesions in patients with cutaneous lupus erythematosus (CLE) after ultraviolet (UV) irradiation.

METHODS

In situ nick translation and TUNEL were performed to detect apoptosis in 85 skin biopsy specimens from patients with various subtypes of CLE. Specimens from normal healthy donors and patients with polymorphous light eruption were used as controls. In addition to assessment of primary lesions, provocative phototesting was carried out to investigate events occurring secondary to UV irradiation during a very early stage of lesion formation.

RESULTS

A significant increase in apoptotic nuclei was found in the upper epidermal layer of primary and UV light-induced skin lesions of CLE patients compared with controls. In tissue sections obtained from control subjects at 24 hours after a single exposure to UV light, a slight increase in the count of epidermal apoptotic nuclei was present as compared with skin tissue from CLE patients obtained under the same conditions before lesion formation. In sections obtained from controls at 72 hours after irradiation, a significant decrease in the apoptotic nuclei count was observed, consistent with a proper clearance of apoptotic cells in the period between 24 and 72 hours after irradiation. In striking contrast, the number of apoptotic nuclei increased significantly within this period in tissue sections from patients with CLE.

CONCLUSION

These data support the hypothesis that apoptotic cells accumulate in the skin of patients with CLE after UV irradiation, as a result of impaired or delayed clearance. The nonengulfed cells may undergo secondary necrosis and release proinflammatory compounds and potential autoantigens, which may contribute to the inflammatory micromilieu that leads to formation of skin lesions in this disease.

A deficiency in the in vivo clearance of apoptotic cells is a feature of the NOD mouse

Deficiencies in apoptotic cell clearance have been linked to autoimmunity. Here we examined the time-course of peritoneal macrophage phagocytosis of dying cells following the direct injection of apoptotic thymocytes into the peritoneum of NOD mice and BALB/c controls. Macrophages from NOD mice demonstrated a profound defect in the phagocytosis of apoptotic thymocytes as compared to control macrophages. Nonobese diabetic mice also demonstrated a decrease in the clearance of apoptotic cell loads following an apoptotic stimulus to thymocytes (dexamethasone) when compared to BALB/c or NOR controls. Further, NOD mice demonstrated an increase in apoptotic cell load following an apoptotic stimulus to keratinocytes (ultraviolet light, UVB) when compared to control strains. Animals deficient in macrophage phagocytosis of apoptotic debris often manifest an autoimmune phenotype characterized by the production of antinuclear autoantibodies (ANA). We determined whether increased apoptotic cell loads (through repeated exposure to UVB irradiation) could accelerate such autoimmune phenomena in young NOD mice. Following repeated UVB irradiation, NOD mice, but not BALB/c or NOR controls, developed ANA. We propose that abnormalities in apoptotic cell clearance by macrophages predispose NOD mice to autoimmunity.

Photosensitivity in lupus erythematosus

Lupus erythematosus (LE) is an autoimmune disease which can be triggered by environmental factors such as solar irradiation. It has long been observed that especially ultraviolet (UV) exposure can induce and exacerbate skin lesions in patients with this disease. However, despite the frequency of photosensitivity in LE, the mechanisms by which UV irradiation activates autoimmune responses is only now becoming increasingly unfolded by advanced molecular and cellular biological investigations. Phototesting, according to a standardized protocol with UVA and UVB irradiation has proven to be a valid model to study photosensitivity in various subtypes of LE and to evaluate the underlying pathomechanisms of this disease. Detailed analysis of the molecular events that govern lesion formation in experimentally photoprovoced LE showed increased accumulation of apoptotic keratinocytes and impaired expression of the inducible nitric oxide synthase (iNOS). In the near future, gene expression profiling and proteomics will further increase our knowledge on the complexity of the "UV response" in LE. This review summarizes the current understanding of the clinical and molecular mechanisms that initiate photosensitivity in this disease.

A human-specific TNF-responsive promoter for Goodpasture antigen-binding protein

The Goodpasture antigen-binding protein, GPBP, is a serine/threonine kinase whose relative expression increases in autoimmune processes. Tumor necrosis factor (TNF) is a pro-inflammatory cytokine implicated in autoimmune pathogenesis. Here we show that COL4A3BP, the gene encoding GPBP, maps head-to-head with POLK, the gene encoding for DNA polymerase kappa (pol kappa), and shares with it a 140-bp promoter containing a Sp1 site, a TATA-like element, and a nuclear factor kappa B (NFkappaB)-like site. These three elements cooperate in the assembly of a bidirectional transcription complex containing abundant Sp1 and little NFkappaB that is more efficient in the POLK direction. Tumour necrosis factor cell induction is associated with Sp1 release, NFkappaB recruitment and assembly of a complex comparatively more efficient in the COL4A3BP direction. This is accomplished by competitive binding of Sp1 and NFkappaB to a DNA element encompassing a NFkappaB-like site that is pivotal for the 140-bp promoter to function. Consistently, a murine homologous DNA region, which contains the Sp1 site and the TATA-like element but is devoid of the NFkappaB-like site, does not show transcriptional activity in transient gene expression assays. Our findings identify a human-specific TNF-responsive transcriptional unit that locates GPBP in the signalling cascade of TNF and substantiates previous observations, which independently related TNF and GPBP with human autoimmunity.

C1q: Its Functions within the Innate and Adaptive Immune Responses and its Role in Lupus Autoimmunity

The complement cascade is a multi-faced effector component of the innate immune response. C1q is the recognition component of the classical pathway of complement activation. In addition, C1q has been recognized to serve a number of other biological functions including a modulating role on cellular functions within the adaptive immune response. The importance of C1q to normal immune regulation is reflected by the fact that greater than 90% of individuals who have complete congenital deficiency of C1q have been observed to develop early-onset photosensitive systemic lupus erythematosus (SLE). As a number of single nucleotide polymorphisms have been identified in three C1q genes, it is possible that more subtle variations in C1q expression could be a risk factor for cutaneous LE and SLE. Thus, a more comprehensive delineation of complotype could be of increasing clinical importance in the future.

Ultraviolet-B recruits mannose-binding lectin into skin from non-cutaneous sources

Mannose-binding lectin (MBL) is an integral part of the innate immune system and functions as an opsonin by binding to pathogens and certain apoptotic cells to promote their uptake by phagocytes. We recently identified an association of low-producing MBL polymorphisms with adult dermatomyositis (DM). Our model is that MBL deficiency leads to a defect in the clearance of apoptotic debris in the skin, thereby predisposing to photosensitive autoimmune disease. In this study, we sought to determine whether MBL binds within the epidermis, and to determine its source, and potential function of this binding. We demonstrated that the MBL is present in irradiated, but not in non-irradiated skin, and in irradiated skin it is bound to apoptotic keratinocytes (KC). We found that MBL is not made by KC, showing indirectly that it comes from an exogenous source, despite the fact that other complement components are made by KC and upregulated by ultraviolet irradiation. Finally, we demonstrated that non-KC-derived MBL bound to apoptotic KC in vitro and increased the uptake of these cells by dendritic cells. We hypothesize that MBL may facilitate non-inflammatory clearance of apoptotic debris in patients with photosensitive forms of DM.

Ultraviolet radiation-induced injury, chemokines, and leukocyte recruitment: An amplification cycle triggering cutaneous lupus erythematosus

OBJECTIVE

To investigate the activation and recruitment pathways of relevant leukocyte subsets during the initiation and amplification of cutaneous lupus erythematosus (LE).

METHODS

Quantitative real-time polymerase chain reaction was used to perform a comprehensive analysis of all known chemokines and their receptors in cutaneous LE lesions, and the cellular origin of these chemokines and receptors was determined using immunohistochemistry. Furthermore, cytokine- and ultraviolet (UV) light-mediated activation pathways of relevant chemokines were investigated in vitro and in vivo.

RESULTS

In the present study, we identified the CXCR3 ligands CXCL9 (interferon-gamma [IFNgamma]-induced monokine), CXCL10 (IFNgamma-inducible protein 10), and CXCL11 (IFN-inducible T cell alpha chemoattractant) as being the most abundantly expressed chemokine family members in cutaneous LE. Expression of these ligands corresponded with the presence of a marked inflammatory infiltrate consisting of mainly CXCR3-expressing cells, including skin-homing lymphocytes and blood dendritic cell antigen 2-positive plasmacytoid dendritic cells (PDCs). Within cutaneous LE lesions, PDCs accumulated within the dermis and were activated to produce type I IFN, as detected by the expression of the IFNalpha-inducible genes IRF7 and MxA. IFNalpha, in turn, was a potent and rapid inducer of CXCR3 ligands in cellular constituents of the skin. Furthermore, we demonstrated that the inflammatory CXCR3 ligands cooperate with the homeostatic chemokine CXCL12 (stromal cell-derived factor 1) during the recruitment of pathogenically relevant leukocyte subsets. Moreover, we showed that UVB irradiation induces the release of CCL27 (cutaneous T cell-attracting chemokine) from epidermal compartments into dermal compartments and up-regulates the expression of a distinct set of chemokines in keratinocytes.

CONCLUSION

Taken together, our data suggest an amplification cycle in which UV light-induced injury induces apoptosis, necrosis, and chemokine production. These mechanisms, in turn, mediate the recruitment and activation of autoimmune T cells and IFNalpha-producing PDCs, which subsequently release more effector cytokines, thus amplifying chemokine production and leukocyte recruitment, finally leading to the development of a cutaneous LE phenotype.

Dermatomyositis: comparative studies of cutaneous photosensitivity in lupus erythematosus and normal subjects

PURPOSE

Cutaneous features of dermatomyositis (DM) strongly suggest that ultraviolet (UV) radiation plays an important role in the pathogenesis of the disease. However, the incidence and the nature of photosensitivity in this disorder have not been established. The aim of this study was to investigate the UVB (290-320 nm) minimal erythema dose (MED) in DM patients in comparison with those in lupus erythematosus (LE) and healthy controls.

METHODS

Non-irradiated back skin of 75 Caucasians with skin types II and III according to the Fitzpatrick classification were present in three different subject groups and tested for photomanifestation on non-irradiated suprascapular back skin with an ETG-1 Erythemtester. The first group included 19 DM patients, the second 30 patients with LE, and the third 26 healthy control volunteers. The MEDs were determined 24 h after irradiation adjusted according to skin type.

RESULTS

Nine of the 19 DM patients (47.4%) demonstrated reduced MEDs to UVB radiation. Seven DM patients (36.8%) had a history of increased cutaneous photosensitivity and four of these (21.1%) reported diseased aggravation after sun exposure. Both the DM and LE patient groups showed reduced MED to UVB radiation (P<0.05) compared with the control group (19.2%). Increased erythemal sensitivity to UVB irradiation was found more frequently in patients with systemic LE and cutaneous discoid LE, than in those with subacute cutaneous LE.

CONCLUSION

DM patients, similar to those with LE, showed a significantly reduced MED to UVB irradiation compared with healthy persons.

Over-expression of TATA binding protein (TBP) and p53 and autoantibodies to these antigens are features of systemic sclerosis, systemic lupus erythematosus and overlap syndromes

The aim of this study was to determine the expression levels of p53 and TATA binding protein (TBP) and the presence of autoantibodies to these antigens in Asian Indian patients with systemic sclerosis (SSc), overlap syndromes (OS) and systemic lupus erythematosus (SLE). Fifty patients with SSc, 20 with OS, including mixed connective tissue diseases (MCTD), 20 with SLE, 10 disease controls (DC) and 25 controls (C) were studied. The over-expression of p53 and TBP antigen was determined quantitatively by sandwich enzyme-linked immunosorbent assay (ELISA), varies between four- and sevenfold higher in patients with SSc, OS and SLE, in comparison to DC and C. The expressed protein antigens were not present as free antigens but as immune-complexes. Autoantibodies to p53 were detected by ELISA in 78% subjects with SSc, 100% with OS and 80% with SLE. Autoantibodies to TBP were observed in 28% patients with SSc, 25% with OS and 15% with SLE. In comparison to healthy controls, the titre of antibodies to p53 was significantly higher in patients with SSc (P = 0.00001) than the patients with OS (P = 0.00279) and SLE (P = 0.00289), whereas the titre of antibodies to TBP was higher in patients with OS (P = 0.00185) than the SLE (P = 0.00673) and the SSc (P = 0.00986) patients. Autoantibodies to p53 and TBP were detected in all these patients and the levels of these two autoantibodies showed weak negative correlation with each other. We propose that the over-expression of these antigens might be due to hyperactive regulatory regions in the p53 and TBP gene.

Photosensitivity in rheumatic diseases

There have been a number of recent advances in the genetic understanding of photosensitive rheumatic diseases, especially subacute cutaneous lupus erythematosus and dermatomyositis. These advances support the concept that increased numbers of ultraviolet light-induced apoptotic cells in skin lead to a supra-threshold concentration of antigenic peptides. The current genetic data suggest that increased keratinocyte apopotosis can result from increased amounts of TNF-alpha that induce apoptosis due to a ultraviolet light-sensitive TNF promoter polymorphism or to decreased clearance of apototic cells due to polymorphisms associated with decreased serum levels of collectins such as C1q and mannose-binding lectin. These diseases are frequently oligogenic, and other yet to be elucidated genes will, in individual patients, lead to increased numbers of apoptotic cells associated with these cutaneous autoimmune diseases. In the presence of specific MHC class I and II genes, antigen-presenting cells initiate a primary immune response that leads to cutaneous, and likely systemic, autoimmune disease.

Lupus-associated toxic epidermal necrolysis: a novel manifestation of lupus?

BACKGROUND

Toxic epidermal necrolysis is an acute mucocutaneous reaction characterized by extensive cutaneous and mucosal sloughing and systemic involvement. It is generally associated with drug ingestion.

OBJECTIVE AND METHODS

We describe 2 patients who developed typical clinical and histopathologic features of toxic epidermal necrolysis with unusual subacute progression, absence of systemic involvement or high-risk drug ingestion, and features of lupus erythematosus.

CONCLUSION

We propose that this constellation of features represents a new entity not previously described. This entity may represent a more severe variant of Rowell's syndrome or, alternatively, a novel manifestation of lupus erythematosus

Mannose binding lectin (MBL) polymorphisms associated with low MBL production in patients with dermatomyositis

One theory for the pathophysiology of photosensitive autoimmune skin diseases is that photoinduction of tumor necrosis factor alpha (TNFalpha) secretion leads to keratinocyte apoptosis and translocation of previously sequestered cellular antigens that then activate the immune system. We previously found an association of the overproducing TNFalpha-308 A variant with adult dermatomyositis and with subacute cutaneous lupus erythematosus. Here we focused on mannose binding lectin (MBL), which is one of several proteins involved in clearance of apoptotic cells and could thereby lessen photosensitive autoimmunity. We examined three variant MBL polymorphisms associated with decreased MBL protein (Asp54, Glu57, and the LX promoter polymorphism) in adult dermatomyositis, subacute cutaneous lupus erythematosus, and discoid lupus, and controls. The variant Asp54 allele was positively associated with adult dermatomyositis in a dose-responsive fashion (p=0.0004), as was the Glu57 allele (p=0.004). None of the three variant MBL alleles considered individually was significantly associated with either subacute cutaneous lupus erythematosus or discoid lupus. In adult dermatomyositis patients homozygous for the wild-type TNFalpha-308G allele (GG), i.e., presumably without elevated TNFalpha production, 69% had at least two of the MBL polymorphisms, versus 20% of healthy GG controls (p=0.0011). Combinations of low-producing MBL variants were over-represented in adult dermatomyositis in a dose-responsive fashion (p=0.0002). In adult dermatomyositis patients with one variant TNFalpha-308 A allele (GA), 46% had at least two MBL polymorphisms, versus 7% of GA controls (p=0.0077). Thus, low-producing MBL genes are very strongly associated with adult dermatomyositis. Our model is that genetic polymorphisms leading to overproduction of apoptotic keratinocytes and then impaired clearance of these cells contribute to the pathogenesis of adult dermatomyositis, a photoinduced autoimmune skin disease.

Associations of tumor necrosis factor alpha and HLA polymorphisms with adult dermatomyositis: implications for a unique pathogenesis

We recently reported that the -308A tumor necrosis factor alpha promoter polymorphism is associated with the photosensitive disorder subacute cutaneous lupus erythematosus and mediates an exaggerated tumor necrosis factor alpha response to ultraviolet B. We now sought to examine the association of this polymorphism with adult dermatomyositis, a photosensitive disease that exhibits some features in common with subacute cutaneous lupus erythematosus. Fifty adult patients with dermatomyositis and 239 healthy, race-matched controls were examined for the -308A tumor necrosis factor alpha polymorphism and the more common -308G allele. The frequency of the -308A allele was 0.27 in the entire dermatomyositis group, versus 0.14 in the controls (p = 0.003, chi2 2 x 2 table). Caucasians were the only racial/ethnic group in our study large enough to allow separate statistical analysis (47 dermatomyositis, 223 controls). The frequency of the -308A allele was 0.26 for dermatomyositis and 0.14 for controls (p = 0.014). Caucasians are known to exhibit a linkage disequilibrium between -308A and HLA-DR3, which we previously found to be significantly enhanced in subacute cutaneous lupus erythematosus patients. In contrast, we now found no increase in the association of -308A and HLA-DR3 in Caucasians with dermatomyositis compared to controls. Consistent with this observation, the association of these two genes in dermatomyositis was significantly less than we previously reported in Caucasians with subacute cutaneous lupus erythematosus (p = 0.016). We conclude that the tumor necrosis factor -308A polymorphism is associated with dermatomyositis, which suggests a pathophysiologic contribution from ultraviolet-induced production of tumor necrosis factor alpha, similar to subacute cutaneous lupus erythematosus. The differences in linkage with HLA-DR3, as well as several divergent clinical features, indicate that there are also fundamental mechanistic differences between dermatomyositis and subacute cutaneous lupus erythematosus.

Cutaneous lupus erythematosus: a review

This article will review and update information about the pathogenesis, clinical presentation, diagnosis, and treatment of cutaneous lupus erythematosus. Lupus erythematosus (LE) can present as a skin eruption, with or without systemic disease. Cutaneous LE is subdivided into chronic cutaneous LE, subacute cutaneous LE and acute LE. The prevalence of systemic lupus erythematosus (SLE) is 17-48/100,000 population worldwide. Skin disease is one of the most frequent clinical complaints of patients suffering from SLE. It has been found to occur in up to 70% of patients during the course of the disease. The most frequent mucocutaneous manifestations of SLE are malar rash (40%), alopecia (24%), and oral ulcers (19%). It has been suggested that risk factors that are more likely to signal transition of cutaneous into systemic LE are high ANA titers (> 1:320) and the presence of arthralgias. CLE patients who exhibit these symptoms should be monitored closely, since they may be at increased risk to develop SLE.

Clearance of apoptotic beta-cells is reduced in neonatal autoimmune diabetes-prone rats

The kinetics of beta-cell death in neonatal diabetes-prone (BBdp) and diabetes-resistant (BBdr) BioBreeding rats was investigated using both direct (histochemical) and indirect (mathematical modelling) techniques. In both BBdp and BBdr rats, the incidence of TUNEL positive beta-cells increased until 10 days of age before declining. The number of apoptotic beta-cells was significantly higher in BBdp as compared to BBdr neonates from birth until 20 days of age (P<0.05). Using a mathematical model applied to the time course of beta-cell mass and replication rate, a wave of net beta-cell loss was detected between 10 and 20 days of age in both strains. In contrast to the observed difference in the incidence of TUNEL positive beta-cells, with the model-based approach we found no difference in the rate of beta-cell apoptosis between BBdp and BBdr rats prior to weaning. As the number of apoptotic cells present in a tissue depends on the rate at which cells die and the rate at which the apoptotic cell debris is cleared, we compared in vitro phagocytosis of apoptotic thymocytes by peritoneal macrophages from 2-week-old BBdp and BBdr rats. Macrophages from BBdp neonates engulfed significantly less apoptotic cells as compared to BBdr neonates (P<0.0005). Taken together, these findings suggest that there is impaired clearance of apoptotic beta-cells in diabetes-prone BB rats during the neonatal period.

Presence of cutaneous interferon-alpha producing cells in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) patients have increased levels of interferon-alfa (IFN-alpha) in the circulation but a reduced number of functionally intact natural IFN-alpha producing cells (IPC) in peripheral blood. In search for tissue localisation of activated IPC, we investigated skin biopsies from SLE patients for the occurrence of such cells. Eleven SLE patients with inflammatory skin lesions and six healthy controls were biopsied. An immunohistochemical technique (IH) and in situ hybridisation (ISH) were used to detect intracellular IFN-alpha protein and IFN-alpha mRNA, respectively. In all 11 biopsies from SLE lesions, a high number of IPC were detected by IH. In the nonlesional SLE biopsies we could also demonstrate IPC in 10/11 patients. In 6/11 SLE patients, IFN-alpha mRNA containing cells could be detected in the specimens. A low number of IPC were detected in 1/6 healthy controls by IH, but no ISH positive cells were seen. Our results demonstrate that SLE patients have active IPC in both dermal lesions and in noninflammatory skin. A recruitment of IPC from blood to peripheral tissues may explain the low number of circulating natural IPC in SLE patients. Because the type I IFN system is involved in the SLE disease process, these results are of interest for the understanding of the pathogenesis in SLE.

Decreased susceptibility to Fas-induced apoptosis of systemic sclerosis dermal fibroblasts

OBJECTIVE

To determine whether dysregulated apoptosis of systemic sclerosis (SSc) fibroblasts contributes to progressive fibrosis by promoting fibroblast longevity.

METHODS

We examined the pattern of fibroblast proliferation and apoptosis in SSc skin lesions and the susceptibility of cultured SSc dermal fibroblasts to apoptosis. Skin biopsy samples from SSc patients and control subjects were used to establish fibroblast cultures and were examined histologically. In skin sections, apoptosis was examined by TUNEL, and proliferation by immunostaining for proliferating cell nuclear antigen. Susceptibility of fibroblasts to apoptosis induced in vitro by different stimuli was studied by TUNEL. Expression of Bcl-2, Bcl-x, and Bax proteins in cultured fibroblasts was studied by Western blotting.

RESULTS

Proliferation of dermal fibroblasts was not observed in normal skin but was present in skin from patients with SSc and other inflammatory skin diseases. Apoptosis of fibroblasts in SSc fibrotic skin lesions was not observed. In vitro, SSc fibroblasts were specifically resistant to apoptosis induced by Fas receptor stimulation but had normal susceptibility to apoptosis induced by nonspecific stimuli (protein kinase inhibition or serum withdrawal). Decreased susceptibility to Fas stimulation was not caused by decreased levels of surface Fas receptor. In SSc fibroblasts, quiescence induced by confluence and serum starvation was followed by an abnormal down-regulation of proapoptotic Bax protein. Up-regulation of the Bax:Bcl-2 ratio in SSc fibroblasts by Bcl-2 antisense oligonucleotides restored their susceptibility to Fas-mediated apoptosis.

CONCLUSION

Our findings suggest that abnormal apoptotic regulation in fibroblasts can contribute to the pathogenesis of progressive fibrosis in SSc. Modulation of Bcl-2-related proteins appears to be a potential target for the development of apoptosis-based antifibrotic strategies.

Plasmacytoid dendritic cells (natural interferon- alpha/beta-producing cells) accumulate in cutaneous lupus erythematosus lesions

Plasmacytoid dendritic cell (P-DC) precursors in peripheral blood produce large amounts of interferon (IFN)-alpha/beta when triggered by viruses. However, when incubated with interleukin-3 and CD40 ligand, the same precursors differentiate into mature DCs that stimulate naïve CD4(+) T cells to produce Th2 cytokines. We recently reported that P-DCs accumulate in nasal mucosa of experimentally induced allergic rhinitis, supporting a role for this DC subset in Th2-dominated inflammation. Here we examined whether P-DCs accumulate in cutaneous lesions of lupus erythematosus (LE), a disorder associated with increased IFN-alpha/beta production. Our results showed that P-DCs were present in 14 out of 15 tissue specimens of cutaneous LE lesions, but not in normal skin. Importantly, the density of P-DCs in affected skin correlated well (r(s) = 0.79,P < 0.0005) with the high number of cells expressing the IFN-alpha/beta-inducible protein MxA, suggesting that P-DCs produce IFN-alpha/beta locally. Accumulation of P-DCs coincided also with the expression of L-selectin ligand peripheral lymph node addressin on dermal vascular endothelium, adding further support to the notion that these adhesion molecules are important in P-DC extravasation to peripheral tissue sites. Together, our findings suggested that P-DCs are an important source of IFN-alpha/beta in cutaneous LE lesions and may therefore be of pathogenic importance.

Goodpasture antigen-binding protein, the kinase that phosphorylates the goodpasture antigen, is an alternatively spliced variant implicated in autoimmune pathogenesis

The non-collagenous C-terminal domain of the alpha(3) chain of collagen IV is the autoantigen in Goodpasture disease, an autoimmune disorder described only in humans. Specific N-terminal phosphorylation is a biological feature unique to the human domain when compared with other homologous domains lacking immunopathogenic potential. We have recently cloned from a HeLa-derived cDNA library a novel serine/threonine kinase (Goodpasture antigen-binding protein (GPBP)) that phosphorylates the N-terminal region of the human domain (Raya, A. Revert, F, Navarro, S. and Saus J. (1999) J. Biol. Chem. 274, 12642-12649). We show here that the pre-mRNA of GPBP is alternatively spliced in human tissues and that the most common transcript found encodes GPBPDelta26, a molecular isoform devoid of a 26-residue serine-rich motif. Recombinantly expressed GPBPDelta26 exhibits lower activity than GPBP, due at least in part to a reduced ability of GPBPDelta26 to interact and to form very active high molecular weight aggregates. In human tissues, GPBP shows a more limited expression than GPBPDelta26 but displays a remarkable preference for the small vessels and for histological structures targeted by natural autoimmune responses including alveolar and glomerular basement membranes, the two main targets in Goodpasture disease. GPBP expression is, in turn, up-regulated in the striated muscle of a Goodpasture patient and in other autoimmune conditions including cutaneous lupus erythematosus, pemphigoid, and lichen planus.

IFN-gamma transgenic mice: clues to the pathogenesis of systemic lupus erythematosus?

Transgenic mice overexpressing IFN-gamma in the epidermis develop an inflammatory skin disease resembling cutaneous lupus erythematosus shortly after birth. By 3 months of age, most female transgenics develop a lupus-like syndrome characterised by production of IgG anti-dsDNA, antihistone and antinucleosome autoantibodies. The autoantibodies are nephritogenic, with one-third of females developing a severe immune complex mediated glomerulonephritis. Analysis of these transgenics suggests that pathogenic autoantibodies arise via an antigen-driven T-cell-dependent mechanism with apoptotic keratinocytes acting as a potential source of autoantigen. The mechanism of autoantibody production in IFN-gamma transgenics may be relevant to human lupus and is consistent with a central role for cutaneous T cells in the pathogenesis of systemic lupus erythematosus in man.