Efficacy and safety of TM5614 in combination with paclitaxel in the treatment of paclitaxel-resistant cutaneous angiosarcoma: Phase II study protocol.

Cutaneous angiosarcoma (CAS) is an endothelial cell-derived, highly aggressive type of vascular tumour. Although chemoradiotherapy with paclitaxel (PTX) is recognized as a first-line therapy for CAS, second-line therapy for CAS remains controversial, and there is no standard therapy for taxane-resistant CAS. Plasminogen activator inhibitor-1 (PAI-1) is associated with poor clinical outcomes, and elevated levels of PAI-1 in both tissue and serum are correlated with poor response to therapy in various cancers, including skin cancers. Since PAI-1 protects endothelial cells from Fas ligand-mediated apoptosis, PAI-1 inhibition might induce apoptosis of endothelial cell-derived tumours such as CAS. This is a single-arm, open-label, multi-institutional, Phase 2 clinical trial to assess the efficacy and safety of PTX in combination with TM5614 (PAI-1 inhibitor) in patients with PTX-resistant CAS. PTX will be administered for 28 weeks, with oral administration of TM5614. The primary endpoint of this study will be the overall response rate (ORR) at 28 weeks after starting treatment (central image evaluation). The secondary endpoint will include the ORR at 28 weeks after starting treatment (investigator evaluation), ORR at 8 weeks and 16 weeks after initiation of treatment (central and investigator evaluation), progression-free survival, overall survival, disease control rate and safety profiles. Assuming the null hypothesis of a response rate of 13.6% and an alternative hypothesis of 45%, a minimum of 15 patients are required to achieve a two-sided, Type I error of 5% and power of 70% based on the exact binomial distribution. Data quality control will be conducted by a combination of centralized (remote) and on-site monitoring. This study will contribute to the development of novel combination therapy for PTX-resistant CAS patients, which remains an unmet clinical need.

Possible effects of plasminogen activator inhibitor-1 on promoting angiogenesis through matrix metalloproteinase 9 in advanced mycosis fungoides.

Mycosis fungoides (MF) progresses slowly before advancing to skin tumors followed by lymph node and visceral involvement. Among MF progression, stage IIB is an initial time point of tumor formation in MF. Since MF in tumor stage possess abundant blood vessels, it is important to evaluate the pro-angiogenic factors before and after MF in stage IIB. In this report, we investigated pro-angiogenic soluble factors in MF patients, as well as its pro-angiogenetic effects on tumor cells and stroma cells. We first evaluated the serum levels of pro-angiogenic factors in 9 MF patients without tumor formation and 8 MF patients with tumor formation. Among them, the serum MMP-9 and plasminogen activator inhibitors 1 (PAI-1) was significantly increased in MF with tumor formation compared in MF without tumor formation, leading to favorable formation of human dermal microvascular endothelial cells tube networks. Moreover, PAI-1 stimulation significantly increased the mRNA expression and protein production MMP-9 on monocytes derived M2 macrophages and HUT-78. Furthermore, since MMP-9 production from tumor cells as well as stromal cells is suppressed by bexarotene, we evaluate the baseline serum pro-angiogenic factors including MMP-9 in 16 patients with advanced cutaneous T cell lymphoma treated with bexarotene. The serum levels of MMP-2 and MMP-9 was significantly increased in bexarotene non-responded patients compared to responded patients. Our present study suggested the significance of MMP-9 and PAI-1 for the progression of MF stage toward to the tumor stage, and could be a therapeutic target in future.

Phase II, multicenter study of plasminogen activator inhibitor-1 inhibitor (TM5614) plus nivolumab for treating anti-PD-1 antibody-refractory malignant melanoma: TM5614-MM trial.

BACKGROUND: Anti-programmed cell death 1 antibodies (anti-PD-1 Abs) are widely used for advanced melanoma, but the efficacy of an anti-PD-1 Abs is limited in the Asian population. There remains an unmet need to improve the therapeutic effects of anti-PD-1 Abs treatment, particularly in melanoma patients who are refractory to anti-PD-1 Abs. The aim was to evaluate anti-PD-1 Abs treatment in combination with TM5614 (plasminogen activator inhibitor-1: PAI-1 inhibitor) in patients with unresectable melanoma. METHODS: The TM5614-MM study was a multicentre, open-label, single-arm, phase 2 clinical trial to evaluate the efficacy and safety of nivolumab in combination with TM5614 in patients with advanced, unresectable malignant melanoma recruited at 7 Japanese institutes between 13 September 2021 and 31 March 2023. Patients with metastatic or unresectable melanoma previously treated with anti-PD-1 Abs were enrolled. Nivolumab 480 mg was administered intravenously every 4 weeks for 8 weeks, while TM5614 was administered orally at a dose of 120 mg (0-4 weeks) and 180 mg once daily (5-8 weeks). The primary endpoint was the overall response rate after 8 weeks of concomitant use of TM5614. RESULTS: Thirty nine patients were enrolled, and 34 patients in the anti-PD-1 Abs-refractory cohort. The overall response rate at 8 weeks was 25.9% (95% CI: 12.9-44.9%; P = .027) in 27 anti-PD-1-Abs refractory patients by investigator assessment in the protocol per set cohort. Seven patients discontinued treatment due to progressive disease or adverse events. Treatment-related grade 3 or higher adverse events occurred in 3 of 39 patients (7.7%) in the intention-to-treat cohort. CONCLUSIONS: TM5614 in combination with nivolumab is well-tolerated and effective in anti-PD-1 Abs-refractory, unresectable melanoma. TRIAL REGISTRATION: This trial was registered with Clinical Trial gov, jRCT2021210029.

Targeting B cells for treatment of systemic sclerosis.

PURPOSE OF REVIEW: The pathogenesis of systemic sclerosis (SSc) has been linked to dysfunctional B cells as demonstrated in previous research. This review aims to show the evidence and ongoing clinical trials of B cell-targeted therapy and overview the various aspects of B cell involvement in SSc. RECENT FINDINGS: We provide an overview of the current understanding and therapeutic strategies targeting B cells in SSc patients. Several molecular targets of B cells have been identified for treating SSc, including CD20, CD19, B-cell activating factor (BAFF), and proteasome. SUMMARY: Many clinical trials have demonstrated that B cells play a critical role in the pathogenesis of SSc and may be a potential therapeutic target to improve disease symptoms. Although large-scale clinical studies are needed, various B cell-targeted therapies have the potential to address the unmet needs of SSc patients.

Plasminogen activating inhibitor-1 promotes angiogenesis in cutaneous angiosarcomas.

Plasminogen activating inhibitor-1 (PAI-1) is associated with poor clinical outcomes, and elevated levels of PAI-1 in both tissue and serum are correlated with poor response to therapy in various cancers, including skin cancer. Cutaneous angiosarcoma (CAS) is a vascular tumor histologically characterized by detachment of endothelial cell-derived tumor cells. Since CAS expresses multiple angiogenic growth factors and has increased expressions of angiogenic receptor tyrosine kinase transcripts including VEGFR1/2/3, angiogenesis-promoting factors are potential drug targets in CAS. In this study, the expression of PAI-1 was examined in 31 cases of CAS, and the immunomodulatory effects of PAI-1 on a human CAS cell line, ISO-HAS-B, were evaluated. We found that, of the angiogenesis-promoting factors, PAI-1 was expressed in almost all cases of CAS, and PAI-1 increased the mRNA expressions of IL-23p19, VEGF-C, CXCL5 and CCL20 on ISO-HAS-B. Moreover, PAI-1 stimulated ISO-HAS-B culture supernatant promoted favourable tube networks, suggesting that these tumor-derived factors promote the pro-angiogenic effect on tumor development. In addition, IL-23p19 was expressed in 61.3% of cases, whereas VEGF-C was expressed in 41% of cases. The results of the present study suggest that PAI-1 promotes angiogenesis that results in tumor progression in CAS.

The Antimicrobial Peptide Cathelicidin Exerts Immunomodulatory Effects via Scavenger Receptors.

An active form of cathelicidin antimicrobial peptide, LL-37, has immunomodulatory and stimulatory effects, though the specific pathways are not clear. The purpose of this study was to identify the cellular pathways by which LL-37 amplifies the inflammation induced by damage-associated molecular patterns (DAMPs). We performed DNA microarray, reverse transcription polymerase chain reaction, immunoblotting, and proximity ligation assays using cultured keratinocytes treated with LL-37 and/or the DAMP poly(I:C), a synthetic double-stranded RNA. In contrast to the combination of LL-37 and poly(I:C), LL-37 alone induced genes related to biological metabolic processes such as VEGFA and PTGS2 (COX-2). Inhibition of FPR2, a known receptor for cathelicidin, partially suppressed the induction of VEGFA and PTGS2. Importantly, VEGFA and PTGS2 induced by LL-37 alone were diminished by the knockdown of scavenger receptors including SCARB1 (SR-B1), OLR1 (SR-E1), and AGER (SR-J1). Moreover, LL-37 alone, as well as the combination of LL-37 and poly(I:C), showed proximity to the scavenger receptors, indicating that LL-37 acts via scavenger receptors and intermediates between them and poly(I:C). These results showed that the broad function of cathelicidin is generally dependent on scavenger receptors. Therefore, inhibitors of scavenger receptors or non-functional mock cathelicidin peptides may serve as new anti-inflammatory and immunosuppressive agents.

[AN ADOLESCENT CASE OF HAE-NL-C1INH (WHO WAS) MISDIAGNOSED WITH WHEAT ALLERGY AND MULTIPLE DRUG ALLERGIES].

Hereditary angioedema (HAE) is frequently misdiagnosed as drug allergy. It is essential to differentiate HAE from allergy. Diagnosing HAE-normal-C1INH (conventional HAE type III), presenting normal C1-INH, is even more difficult. Here, we report a case of a 17-year-old female diagnosed with HAE and having labeled wheat and multiple drug allergies. She had been suffering from skin edema and abdominal symptoms since childhood. After taking wheat at 13 years old, she had multiple episodes of the same symptoms. Wheat allergy was suspected, and she started eliminating wheat. Multiple attacks were observed after several drug use, and drug allergy was labeled. However, her attacks did not improve after eliminating wheat and the suspected drugs. Her C4 and C1-INH activity was normal, but we diagnosed her with HAE-normal-C1INH based on her family history, multiple attacks after dental procedures, ineffective antihistamines, and significant efficacy of C1-INH infusion. A double-blind, placebo-controlled wheat challenge test at our hospital was negative, and wheat removal was lifted. Drugs could be de-labeled by allergic tests and history. Repeated attacks of unexplained edema and abdominal pain should be differentiated from HAE and lead to an appropriate diagnosis.

Rationally-based therapeutic disease modification in systemic sclerosis: Novel strategies.

Systemic sclerosis (SSc) is a highly challenging chronic condition that is dominated by the pathogenetic triad of vascular damage, immune dysregulation/autoimmunity and fibrosis in multiple organs. A hallmark of SSc is the remarkable degree of molecular and phenotypic disease heterogeneity, which surpasses that of other complex rheumatic diseases. Disease trajectories in SSc are unpredictable and variable from patient to patient. Disease-modifying therapies for SSc are lacking, long-term morbidity is considerable and mortality remains unacceptably high. Currently-used empirical approaches to disease modification have modest and variable clinical efficacy and impact on survival, are expensive and frequently associated with unfavorable side effects, and none can be considered curative. However, research during the past several years is yielding significant advances with therapeutic potential. In particular, the application of unbiased omics-based discovery technologies to large and well-characterized SSc patient cohorts, coupled with hypothesis-testing experimental research using a variety of model systems is revealing new insights into SSc that allow formulation of a more nuanced appreciation of disease heterogeneity, and a deepening understanding of pathogenesis. Indeed, we are now presented with numerous novel and rationally-based strategies for targeted SSc therapy, several of which are currently, or expected to be shortly, undergoing clinical evaluation. In this review, we discuss promising novel therapeutic targets and rationally-based approaches to disease modification that have the potential to improve long-term outcomes in SSc.

Successful treatment of metastatic fibrosarcomatous dermatofibrosarcoma protuberans with imatinib mesylate.

Dermatofibrosarcoma protuberans (DFSP) is a fibrohistiocytic tumor characterized by a high risk of local recurrence but a low risk of metastasis. A small subpopulation of DFSP undergoes fibrosarcomatous (FS) change, and approximately 15%-57% of cases of DFSP with FS change metastasizes, leading to a poor prognosis. In this report, a case of metastatic FS-DFSP that was successfully treated with imatinib mesylate in which the IHC staining pattern of recurrent DFSP was quantitatively analyzed in primary and metastatic DFSP areas, is described. Importantly, the recurrent area was composed of two IHC staining patterns (CD34low PD-L1high Ki67high , and CD34high PD-L1low Ki67low pattern), while the metastatic area showed a clonal pattern (CD34high PD-L1low Ki67intermediate ) in the present case. In this report, we described a case of metastatic fibrosarcomatous DFSP successfully treated with imatinib mesylate. This case suggests a subpopulation of DFSP with a favorable metastatic pattern.

Cutaneous T cell lymphoma treated with mogamulizumab monotherapy and mogamulizumab plus etoposide combined therapy: A real-world case series.

Since the efficacy of mogamulizumab has been confirmed by a phase III, randomized study, mogamulizumab is one of the promising first-line therapies for advanced cutaneous T cell lymphoma (CTCL), though its efficacy is not completely satisfactory. Therefore, several anti-lymphoma drugs such as etoposide were recently used to enhance the anti-tumor effects of mogamulizumab for the treatment of mycosis fungoides (MF). In this report, the anti-tumor effects of mogamulizumab and post mogamulizumab therapy were retrospectively evaluated in 11 cases of CTCL in real-world clinical practice. The best response rate (RR) was 45.5% (95% confidence interval [CI], 21.3%-72.0%) for the total cohort, 50.0% (95%CI, 21.5%-78.5%) for the MF cohort, and 33.3% (95%CI, 5.6%-79.8%) for the primary cutaneous peripheral T cell lymphoma not otherwise specified (PCPTCL-NOS) cohort. The objective response rate (ORR) at 1 month (ORR1) for the total cohort was 45.5% (95%CI, 21.3%-72.0%), and ORR at 4 months (ORR4) was 27.3% (95%CI, 9.2%-57.1%). The mean time to next treatment (TTNT) was 16.0 weeks (3-100 weeks) for all patients, 16.5 months (3-100 weeks) for the MF cohort, and 9.0 (7-16) weeks for the PCPTCL-NOS cohort. The efficacy rate of etoposide-based therapy was 71.4% (95%CI, 35.9%-98.0%) for all patients, 80% (95%CI, 35.9%-98.0%) in the MF cohort, and 50% (95%CI, 9.5%-90.5%) in the PCPTCL-NOS cohort. The median duration of response was 182 (45-323) weeks. The safety profile of mogamulizumab monotherapy in the present cohort was comparable to the previous phase III, randomized trial. The present study suggests that the efficacy and safety profiles of mogamulizumab monotherapy as second-line therapy and beyond in a real-world Japanese cohort were comparable to those in the previous phase III, randomized trial.

Immunotherapy for Melanoma: The Significance of Immune Checkpoint Inhibitors for the Treatment of Advanced Melanoma.

Therapeutic options for treating advanced melanoma have progressed rapidly in recent decades. Until 6 years ago, the regimen for treating advanced melanoma consisted mainly of cytotoxic agents such as dacarbazine and type I interferons. Since 2014, anti-programmed cell death 1 (PD1) antibodies have been recognized as anchor drugs for treating advanced melanoma, with or without additional combination drugs such as ipilimumab, but the efficacies of these immunotherapies are not fully satisfactory. In this review, we describe the development of the currently available anti-PD1 Abs-based immunotherapies for advanced melanoma, focusing on their efficacy and immune-related adverse events (AEs), as well as clinical trials still ongoing for the future treatment of advanced melanoma.

A potential contribution of decreased serum galectin-10 levels to systemic inflammation and pulmonary vascular involvement in systemic sclerosis.

OBJECTIVE: Galectin-10 (Gal-10) is a key molecule involved in eosinophil-mediated suppression of T-cell immune response. Systemic sclerosis (SSc) is characterized by T helper (Th) 2/Th17 immune response and impaired function of regulatory T cells, but the pathological role of Gal-10 has not been studied so far. Therefore, we investigated the clinical correlation of serum Gal-10 levels in SSc patients. METHODS: Serum Gal-10 levels were determined by enzyme-linked immunosorbent assay in 38 patients with diffuse cutaneous SSc (dcSSc), 30 with limited cutaneous SSc and 20 healthy controls. Clinical correlations of serum Gal-10 levels were examined. RESULTS: Serum Gal-10 levels were significantly lower in SSc patients than in healthy controls, especially in dcSSc patients, and inversely correlated with skin score, the percentage of predicted diffusion lung capacity for carbon monoxide and estimated right ventricular systolic pressure (RVSP). Furthermore, serum Gal-10 levels had negative correlations with leucocyte counts and inflammatory parameters. Multivariate regression analysis identified C-reactive protein and RVSP as explanatory parameters for serum Gal-10 levels. CONCLUSION: Decreased serum Gal-10 levels may reflect the impairment of eosinophil-mediated regulatory system for T-cell immune response in SSc, possibly contributing to pulmonary vascular involvement leading to pulmonary arterial hypertension.

Serum S100A12 levels: Possible association with skin sclerosis and interstitial lung disease in systemic sclerosis.

Damage-associated molecular patterns (DAMPs) have drawn much attention as a member of disease-associated molecules in systemic sclerosis (SSc). In this study, we investigated the potential contribution of S100A12, a member of DAMPs, to the development of SSc by evaluating S100A12 expression in the lesional skin and the clinical correlation of serum S100A12 levels. S100A12 expression was markedly elevated in the epidermis of SSc-involved skin at protein levels and in the bulk skin at mRNA levels. The deficiency of transcription factor Fli1, a predisposing factor of SSc, enhanced S100A12 expression and Fli1 occupied the S100A12 promoter in normal human keratinocytes. Serum S100A12 levels were higher in SSc patients, especially in those with diffuse cutaneous involvement, than in healthy controls and positively correlated with skin score. Furthermore, the presence of interstitial lung disease significantly augmented serum levels of S100A12. Importantly, serum S100A12 levels correlated inversely with both per cent forced vital capacity and per cent diffusing capacity for carbon monoxide and positively with serum levels of KL-6 and surfactant protein-D. Collectively, these results indicate a possible contribution of S100A12 to skin sclerosis and interstitial lung disease associated with SSc, further supporting the critical roles of DAMPs in the pathogenesis of this disease.

Serum vasohibin-1 levels: A potential marker of dermal and pulmonary fibrosis in systemic sclerosis.

Vasohibin-1 (VASH-1) is a potent anti-angiogenic factor mainly produced by endothelial cells. In addition, VASH-1 prevents TGF-ß-dependent activation of renal fibroblasts. Since systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy and fibrosis of multiple organs, VASH-1 may be involved in the development of this disease. In this study, we investigated the potential role of VASH-1 in SSc by evaluating the clinical correlation between serum VASH-1 levels and the expression of VASH-1 in SSc-involved skin. Serum VASH-1 levels were higher in SSc patients, especially those with diffuse cutaneous involvement, than in healthy controls and positively correlated with skin score. Furthermore, SSc patients with interstitial lung disease had significantly elevated levels of serum VASH-1 as compared to those without. Importantly, serum VASH-1 levels correlated inversely with both the percentage of predicted vital capacity and the percentage of predicted diffusion lung capacity for carbon monoxide and positively with serum KL-6 levels, but not serum surfactant protein D levels. In SSc-involved skin, VASH1 mRNA was remarkably upregulated compared with healthy control skin, but the major source of VASH-1 was not clear. Fli1 deficiency, a predisposing factor inducing SSc-like endothelial properties, did not affect VASH-1 expression in human dermal microvascular endothelial cells. Collectively, these results suggest that VASH-1 upregulation in the skin and sera is linked to dermal and pulmonary fibrotic changes in SSc, while the contribution of VASH-1 to SSc vasculopathy seems to be limited.

Prognostic Relevance of Pretreatment Peripheral Neutrophil Count and Neutrophil-to-lymphocyte Ratio in Primary Cutaneous Angiosarcoma.

Systemic inflammatory response markers, including neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and monocyte-to-lymphocyte ratio, are useful prognostic factors for various malignant tumours. The aim of this study was to investigate the clinical relevance of these markers in primary cutaneous angiosarcoma. Twenty-six patients were retrospectively divided into 2 groups according to pretreatment peri-pheral blood cell counts or systemic inflammatory response marker levels; overall survival and progression-free survival were compared. Univariate analysis found that high neutrophil count (> 3.1×109/l), high neutrophil-to-lymphocyte ratio (> 2.4), high platelet-to-lymphocyte ratio (> 175) and low lymphocyte count (≤ 1.3×109/l) were related to shorter overall survival, while high neutrophil and low lymphocyte groups had shorter progression-free survival. In multivariate analysis, high neutrophil count and high neutrophil-to- lymphocyte ratio (hazard ratio 7.44 and 5.04, 95% confidence interval 1.48-37.2 and 1.26-20.1, respectiv-ely) were identified as independent prognostic factors for poor overall survival. These results indicate that systemic inflammatory response markers serve as prognostic predictors in primary cutaneous angiosarcoma, as well as in other types of soft-tissue sarcoma.

Increased Regulatory T Cells and Decreased Myeloid-Derived Suppressor Cells Induced by High CCL17 Levels May Account for Normal Incidence of Cancers among Patients with Atopic Dermatitis.

The incidence of cancers in atopic dermatitis (AD) is not increased, although the Th2-dominant environment is known to downregulate tumor immunity. To gain mechanistic insights regarding tumor immunity in AD, we utilized CCL17 transgenic (TG) mice overexpressing CCL17, which is a key chemokine in AD. Tumor formation and lung metastasis were accelerated in CCL17 TG mice when melanoma cells were injected subcutaneously or intravenously. Flow cytometric analysis showed increases in regulatory T cells (Tregs) in lymph nodes in CCL17 TG mice with high mRNA levels of IL-10 and Foxp3 in tumors, suggesting that Tregs attenuated tumor immunity. The frequency of myeloid-derived suppressor cells (MDSCs), however, was significantly decreased in tumors of CCL17 TG mice, suggesting that decreased MDSCs might promote tumor immunity. Expression of CXCL17, a chemoattractant of MDSCs, was decreased in tumors of CCL17 TG mice. Depletion of Tregs by the anti-CD25 antibody markedly reduced tumor volumes in CCL17 TG mice, suggesting that tumor immunity was accelerated by the decrease in MDSCs in the absence of Tregs. Thus, CCL17 attenuates tumor immunity by increasing Tregs and Th2 cells, while it decreases MDSCs through reductions in CXCL17, which may work as a "safety-net" to reduce the risk of malignant tumors in the Th2-dominant environment.

Clinical course of Japanese patients with early systemic sclerosis: A multicenter, prospective, observational study.

OBJECTIVES: To investigate the clinical course of Japanese patients with early diffuse cutaneous systemic sclerosis (dcSSc) and early SSc with interstitial lung disease (ILD). METHODS: We prospectively analyzed the clinical features of 207 Japanese patients with early dcSSc (n = 150) and limited cutaneous SSc (lcSSc) with ILD (n = 57) in 10 medical centers every year for 7 consecutive years. RESULTS: Mean modified Rodnan total skin thickness score (mRSS) was 18.3 and 67.4% of the cohort had ILD. Most patients started immunosuppressive therapy and vasodilators during 7 years (83.4% and 87.9%, respectively). Mean value of mRSS of total patients was significantly reduced from the initial registration after the first year. However, other parameters for physical function associated with skin sclerosis including fist closure, hand extension, and oral aperture were not so ameliorated during the study period. Health Assessment Questionnaire-disability index and serum KL-6 levels were constant throughout the course. Percent vital capacity and the presence of ILD, clinically suspected pulmonary arterial hypertension, and digital ulcers were gradually exacerbated during the period. CONCLUSION: In Japanese early dcSSc patients and SSc patients with ILD, mRSS was continuously reduced during 7 years of follow-up, but there was little improvement of physical disability and organ involvement.

Fli1 deficiency induces endothelial adipsin expression, contributing to the onset of pulmonary arterial hypertension in systemic sclerosis.

OBJECTIVES: Adipsin, or complement factor D, is a serine proteinase catalysing complement factor C3 breakdown, leading to the production of opsonin (C3b), membrane attack complex (C5b-C9) and anaphylatoxins (C3a and C5a). Since adipsin is potentially associated with pulmonary arterial hypertension in SSc, we investigated adipsin expression in dermal small vessels of SSc-involved skin, the mechanism regulating adipsin expression in endothelial cells, and the correlation of serum adipsin levels with SSc clinical symptoms. METHODS: Adipsin expression was assessed by immunohistochemistry with skin sections of SSc and healthy subjects. mRNA levels of target genes and transcription factor binding to the ADIPSIN promoter were evaluated by quantitative reverse transcription PCR and chromatin immunoprecipitation, respectively. Serum adipsin levels were determined by enzyme-linked immunosorbent assay. RESULTS: Adipsin expression was remarkably increased in dermal small vessels of SSc-involved skin as compared with those of healthy control skin. Consistent with the notion that Fli1 deficiency induces SSc-like phenotypes in various types of cells, FLI1 siRNA enhanced adipsin expression at protein and mRNA levels and Fli1 bound to the ADIPSIN promoter in human dermal microvascular endothelial cells. Serum adipsin levels were significantly lower in diffuse cutaneous SSc patients than in limited cutaneous SSc patients and healthy controls, and were associated positively with elevated right ventricular systolic pressure and inversely with interstitial lung disease by multivariate regression analysis. CONCLUSION: Adipsin is up-regulated at least partially by Fli1 deficiency in endothelial cells, potentially contributing to the development of pulmonary vascular involvement in SSc.

Increased Expression of Delta-like Ligand 4 in Mycosis Fungoides.

In many malignancies, dysregulation of the Notch pathways, composed of 4 Notch receptors (Notch1-4) and 5 Notch ligands (Jagged1-2, Delta-like ligand-1, 3-4), is associated with their development. In mycosis fungoides, interaction between Notch1 and Jagged1 is known to activate the Notch pathways and promote the proliferation of tumour cells. However, the involvement of other Notch ligands has not been reported. This study investigated the roles of Delta-like ligand 4 in mycosis fungoides. Delta-like ligand 4 mRNA levels in lesional skin of patients with mycosis fungoides were significantly elevated compared with those of normal controls, and correlated with disease-specific mortality. Immunohistochemical staining demonstrated prominent expression of Delta-like ligand 4 on vascular endothelial cells and tumour cells in mycosis fungoides lesional skin. In addition, Delta-like ligand 4 augmented the proliferation of cutaneous T-cell lym-phoma cell lines. These results suggest that enhanced Delta-like ligand 4 expression may contribute directly to the progression of mycosis fungoides through proliferating tumour cells.

TLR2 Deficiency Exacerbates Imiquimod-Induced Psoriasis-Like Skin Inflammation through Decrease in Regulatory T Cells and Impaired IL-10 Production.

Emerging evidence has demonstrated that Toll-like receptors (TLRs) are associated with autoimmune diseases. In this study, we investigated the role of TLR2 in psoriasis using imiquimod-induced psoriasis-like dermatitis. Although TLR2 signaling is known to play a critical role in the induction of proinflammatory cytokines by immune cells, such as dendritic cells (DCs), macrophages, and monocytes, TLR2 deficiency unexpectedly exacerbated psoriasiform skin inflammation. Importantly, messenger RNA (mRNA) levels of Foxp-3 and IL-10 in the lesional skin were significantly decreased in TLR2 KO mice compared with wild-type mice. Furthermore, flow cytometric analysis of the lymph nodes revealed that the frequency of regulatory T cells (Tregs) among CD4-positive cells was decreased. Notably, stimulation with Pam3CSK4 (TLR2/1 ligand) or Pam2CSK4 (TLR2/6 ligand) increased IL-10 production from Tregs and DCs and the proliferation of Tregs. Finally, adoptive transfer of Tregs from wild-type mice reduced imiquimod-induced skin inflammation in TLR2 KO mice. Taken together, our results suggest that TLR2 signaling directly enhances Treg proliferation and IL-10 production by Tregs and DCs, suppressing imiquimod-induced psoriasis-like skin inflammation. Enhancement of TLR2 signaling may be a new therapeutic strategy for psoriasis.