Serum interleukin-34 levels in dermatomyositis: a potential biomarker for anti-MDA5-antibody-associated interstitial lung disease.

OBJECTIVES: Interleukin (IL)-34 is a hematopoietic cytokine that promotes macrophage activation. Macrophage activation in interstitial lung disease (ILD) in patients with dermatomyositis (DM), especially in those with anti-melanoma differentiation-associated gene 5 (MDA5) antibody suggests the involvement of IL-34 in the disease. However, the association between IL-34 and DM is unknown. In this study, we aimed to determine serum IL-34 levels in DM patients and evaluate their association with DM-ILD. METHODS: We measured serum IL-34 levels in 56 DM patients and 14 age- and sex- matched healthy controls by enzyme-linked immunosorbent assay, and examined their correlation with clinical parameters. In addition, pre- and post-treatment serum IL-34 levels were examined using serum samples from 7 anti-MDA5 antibody-positive DM patients. RESULTS: Serum IL-34 levels were significantly elevated in DM patients, especially in those with anti-MDA5 antibody, compared with healthy controls. In anti-MDA5-antibody-positive DM patients, serum IL-34 levels positively correlated with serum levels of ferritin and anti-MDA5 antibody, which are known biomarkers for rapidly progressive (RP)-ILD. Following combined immunosuppressive therapy, serum IL-34 levels decreased along with ferritin and anti-MDA5 antibody. CONCLUSION: These data suggest that IL-34 may be involved in the development of RP-ILD in anti-MDA5 antibody-positive DM. Serum IL-34 levels can serve as a potential biomarker for RP-ILD in this clinical entity.

Single cell analysis in systemic sclerosis - A systematic review.

In recent years, rapid advances in research methods have made single cell analysis possible. Systemic sclerosis (SSc), a disease characterized by the triad of immune abnormalities, fibrosis, and vasculopathy, has also been the subject of various analyses. To summarize the results of single cell analysis in SSc accumulated to date and to deepen our understanding of SSc. Four databases were used to perform a database search on 23rd June 2023. Assessed Grading of Recommendations Assessment, Development and Evaluation certainty of evidence were performed according to PRISMA guidelines. The analysis was completed on July 2023. 17 studies with 358 SSc patients were included. Three studies used PBMCs, six used skin, nine used lung with SSc-interstitial lung diseases (ILDs), and one used lung with SSc-pulmonary arterial hypertension (PAH). The cells studied included immune cells such as T cells, natural killer cells, monocytes, macrophages, and dendritic cells, as well as endothelial cells, fibroblasts, keratinocytes, alveolar type I cells, basal epithelial cells, smooth muscle cells, mesothelial cells, etc. This systematic review revealed the results of single cell analysis, suggesting that PBMCs, skin, SSc-ILD, and SSc-PAH show activation and dysfunction of cells associated with immune-abnormalities, fibrosis, and vasculopathy, respectively.

Refractory and Recurrent Skin Manifestations in an Adult With Selective Immunoglobulin M Deficiency.

Selective immunoglobulin M (IgM) deficiency (sIgMD) is a rare immunodeficiency disorder characterized by decreased serum levels of IgM. Symptoms of sIgMD include repeated infections and allergic manifestations such as asthma and allergic rhinitis. The etiology and pathology of sIgMD remain largely unknown. Moreover, no genetic cause of sIgMD and associated symptoms has been established. Herein, we describe a 47-year-old female with sIgMD who presented with repeated fevers of unknown cause since childhood. She was referred to our department because of recently developed severe dermatitis without a history of atopic dermatitis or asthma. In addition to histological evaluation by skin biopsy, immunological parameters were investigated in her peripheral blood, and the cellular immunity profile was determined by flow cytometry. The patient with refractory skin manifestations was found to have sIgMD with normal surface levels of IgM in the B cells. Along with recurrence and exacerbation in dermatitis, she showed an increase in peripheral blood eosinophils and serum IgE levels, suggesting an underlying allergic mechanism. The present case strongly indicates the importance of measuring serum IgM levels when seeing patients with recurring fever and intractable skin manifestations.

Elevated serum vasohibin-1 levels in atopic dermatitis: Implications for disease chronicity.

Atopic dermatitis (AD) is often characterized by chronic skin changes of dermal fibrosis, typically regulated by inflammatory and angiogenic factors. However, the significance of angiogenesis inhibitory factors in the development of AD is poorly understood. The present study investigated the potential role of an angiogenesis inhibitory factor, vasohibin-1 (VASH1), in AD by evaluating serum and skin VASH1 levels and their correlation with clinical features. The results showed that VASH1 expression levels in both the serum and skin of patients with AD were significantly elevated compared to healthy controls. Immunohistochemical staining of AD skin showed increased VASH1 expression in dermal vascular endothelial cells. Notably, there was a significant correlation between serum VASH1 levels and disease duration as well as VASH1 and vascular endothelial growth factor A expression levels in the skin tissue of patients with AD. These results may suggest a pathogenesis of increased angiogenesis and associated elevated inhibitory processes accompanying inflammation in the chronic phase of AD.

Spectral changes of light-harvesting complex 2 lacking B800 bacteriochlorophyll a under neutral pH conditions.

Exchange of B800 bacteriochlorophyll (BChl) a in light-harvesting complex 2 (LH2) is promising for a better understanding of the mechanism on intracomplex excitation energy transfer of this protein. Structural and spectroscopic properties of LH2 lacking B800 BChl a (B800-depleted LH2), which is an important intermediate protein in the B800 exchange, will be useful to tackle the energy transfer mechanism in LH2 by the B800 exchange strategy. In this study, we report a unique spectral change of B800-depleted LH2, in which the Qy absorption band of B800 BChl a is automatically recovered under neutral pH conditions. This spectral change was facilitated by factors for destabilization of LH2, namely, a detergent, lauryl dimethylamine N-oxide, and an increase in temperature. Spectral analyses in the preparation of an LH2 variant denoted as B800-recovered LH2 indicated that most BChl a that was released by decomposition of part of B800-depleted LH2 was a source of the production of B800-recovered LH2. Characterization of purified B800-recovered LH2 demonstrated that its spectroscopic and structural features was quite similar to those of native LH2. The current results indicate that the recovery of the B800 Qy band of B800-depleted LH2 originates from the combination of decomposition of part of B800-depleted LH2 and in situ reconstitution of BChl a into the B800 binding pockets of residual B800-depleted LH2, resulting in the formation of stable B800-recovered LH2.

Deregulated JNK signaling enhances apoptosis during hyperthermia.

PURPOSE: c-Jun N-terminal kinases (JNKs) comprise a subfamily of mitogen-activated protein kinases (MAPKs). The JNK group is known to be activated by a variety of stimuli. However, the molecular mechanism underlying heat-induced JNK activation is largely unknown. The aim of this study was to clarify how JNK activity is stimulated by heat. METHODS AND MATERIALS: The expression levels of various MAPK members in HeLa cells, with or without hyperthermia treatment, were evaluated via western blotting. The kinase activity of MAPK members was assessed through in vitro kinase assays. Cell death was assessed in the absence or presence of siRNAs targeting MAPK-related members. RESULTS: Hyperthermia decreased the levels of MAP3Ks, such as ASK1 and MLK3 which are JNK kinase kinase members, but not those of the downstream MAP2K/SEK1 and MAPK/JNK. Despite the reduced or transient phosphorylation of ASK1, MLK3, or SEK1, downstream JNK was phosphorylated in a temperature-dependent manner. In vitro kinase assays demonstrated that heat did not directly stimulate SEK1 or JNK. However, the expression levels of DUSP16, a JNK phosphatase, were decreased upon hyperthermia treatment. DUSP16 knockdown enhanced the heat-induced activation of ASK1-SEK1-JNK pathway and apoptosis. CONCLUSION: JNK was activated in a temperature-dependent manner despite reduced or transient phosphorylation of the upstream MAP3K and MAP2K. Hyperthermia-induced degradation of DUSP16 may induce activation of the ASK1-SEK1-JNK pathway and subsequent apoptosis.

Solo regulates the localization and activity of PDZ-RhoGEF for actin cytoskeletal remodeling in response to substrate stiffness.

Recent findings indicate that Solo, a RhoGEF, is involved in cellular mechanical stress responses. However, the mechanism of actin cytoskeletal remodeling via Solo remains unclear. Therefore, this study aimed to identify Solo-interacting proteins using the BioID, a proximal-dependent labeling method, and elucidate the molecular mechanisms of function of Solo. We identified PDZ-RhoGEF (PRG) as a Solo-interacting protein. PRG colocalized with Solo in the basal area of cells, depending on Solo localization, and enhanced actin polymerization at the Solo accumulation sites. Additionally, Solo and PRG interaction was necessary for actin cytoskeletal remodeling. Furthermore, the purified Solo itself had little or negligible GEF activity, even its GEF-inactive mutant directly activated the GEF activity of PRG through interaction. Moreover, overexpression of the Solo and PRG binding domains, respectively, had a dominant-negative effect on actin polymerization and actin stress fiber formation in response to substrate stiffness. Therefore, Solo restricts the localization of PRG and regulates actin cytoskeletal remodeling in synergy with PRG in response to the surrounding mechanical environment.

Reliability, validity, and sensitivity of the Japanese version of the University of California Los Angeles scleroderma clinical trial consortium gastrointestinal tract instrument: Application to efficacy assessment of intravenous immunoglobulin administration.

This study aimed to develop and assess the reliability, validity, and sensitivity of the Japanese version of the University of California Los Angeles Scleroderma Clinical Trial Consortium gastrointestinal tract (GIT) Instrument 2.0 (the GIT score), as an evaluation tool for GIT symptoms in systemic sclerosis (SSc). The Japanese version of the GIT score was constructed using the forward-backward method. The reliability and validity of this instrument were evaluated in a cohort of 38 SSc patients. Correlation analysis was conducted to assess the relationship between the GIT score and existing patient-reported outcome measures. Additionally, the sensitivity of the GIT score was examined by comparing GIT scores before and after intravenous immunoglobulin (IVIG) administration in 10 SSc-myositis overlap patients, as IVIG has recently demonstrated effectiveness in alleviating GIT symptoms of SSc. As a result, the Japanese version of the GIT score exhibited internal consistency and a significant association with the Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease. Furthermore, the total GIT score, as well as the reflux and distention/bloating subscales, displayed moderate correlations with the EuroQol 5 dimensions (EQ-5D) pain/discomfort subscale and the Short Form-36 body pain subscale. Notably, following IVIG treatment, there was a statistically significant reduction in the total GIT score and multiple subscales. We first validated the Japanese version of the GIT score in Japanese SSc patients in real-world clinical settings. This instrument holds promise for application in future clinical trials involving this patient population.

Serum levels of AGGF1: Potential association with cutaneous and cardiopulmonary involvements in systemic sclerosis.

Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy, aberrant immune activation, and extensive tissue fibrosis of the skin and internal organs. Because of the complicated nature of its pathogenesis, the underlying mechanisms of SSc remain incompletely understood. Angiogenic factor with a G-patch domain and a Forkhead-associated domain 1 (AGGF1) is a critical factor in angiogenesis expressed on vascular endothelial cells, associated with inflammatory and fibrotic responses. To elucidate the possible implication of AGGF1 in SSc pathogenesis, we investigated the association between serum AGGF1 levels and clinical manifestations in SSc patients. We conducted a cross-sectional analysis of AGGF1 levels in sera from 60 SSc patients and 19 healthy controls with enzyme-linked immunosorbent assay. Serum AGGF1 levels in SSc patients were significantly higher than those in healthy individuals. In particular, diffuse cutaneous SSc patients with shorter disease duration had higher levels compared to those with longer disease duration and limited cutaneous SSc patients. Patients with higher serum AGGF1 levels had a higher incidence of digital ulcers, higher modified Rodnan Skin Scores (mRSS), elevated serum Krebs von den Lungen-6 (KL-6) levels, C-reactive protein levels, and right ventricular systolic pressures (RVSP) on the echocardiogram, whereas they had reduced percentage of vital capacity (%VC) and percentage of diffusing capacity of the lungs for carbon monoxide (%DLCO) in pulmonary functional tests. In line, serum AGGF1 levels were significantly correlated with mRSS, serum KL-6 and surfactant protein D levels, RVSP, and %DLCO. These results uncovered notable correlations between serum AGGF1 levels and key cutaneous and vascular involvements in SSc, suggesting potential roles of AGGF1 in SSc pathogenesis.

Cannabinoids for the treatment of autoimmune and inflammatory skin diseases: A systematic review.

In recent years, the medical use of cannabinoids has attracted growing attention worldwide. In particular, anti-inflammatory properties of cannabinoids led to their emergence as potential therapeutic options for autoimmune and inflammatory disorders. Recent studies have also shown that cannabinoid receptors are widely expressed and have endogenous ligands in the skin, suggesting that the skin has its own endocannabinoid system. The aim of this review is to discuss the potential therapeutic effects of cannabinoids in autoimmune and inflammatory skin diseases. Following an overview of cannabinoids and the endocannabinoid system, we describe the cellular and molecular mechanisms of cannabinoids in skin health and disease. We then review the clinical studies of cannabinoids in autoimmune and inflammatory skin diseases including systemic sclerosis (SSc), dermatomyositis (DM), psoriasis (Pso) and atopic dermatitis (AD). A primary literature search was conducted in July 2023, using PubMed and Web of Science. A total of 15 articles were included after excluding reviews, non-human studies and in vitro studies from 389 non-duplicated articles. Available evidence suggests that cannabinoids may be beneficial for SSc, DM, Pso and AD. However, further studies, ideally randomized controlled trials, are needed to further evaluate the use of cannabinoids in autoimmune and inflammatory skin diseases.

Dual blockade of interleukin-17A and interleukin-17F as a therapeutic strategy for liver fibrosis: Investigating the potential effect and mechanism of brodalumab.

Liver fibrosis is a terminal manifestation of various chronic liver diseases. There are no drugs that can reverse the condition. Recently, the importance of interleukin-17 (IL17) in the pathophysiology has been revealed and has attracted attention as a therapeutic target. We aimed to reveal the roles of IL17A and IL17F in liver fibrosis, and to validate the potential of their dual blockade as therapeutic strategy. First, we retrospectively reviewed the longitudinal change of FIB-4 index, a clinical indicator of liver fibrosis, among psoriasis patients treated by brodalumab, which blocks IL17 receptor A (IL17RA). Next, we examined anti-fibrotic efficacy of anti-IL17RA antibody (Ab) in two murine liver fibrosis models by histopathological investigation and real-time reverse transcription polymerase chain reaction (RT-PCR). Finally, we analyzed the effect of IL17A and IL17F upon human hepatic stellate cells with RNA sequencing, real-time RT-PCR, western blotting, chromatin immunoprecipitation, and flow cytometry. Clinical data showed that FIB-4 index significantly decreased among psoriasis patients treated by brodalumab. In vivo studies additionally demonstrated that anti-IL17RA Ab ameliorates liver fibrosis induced by tetrachloride and methionine-choline deficient diet. Furthermore, in vitro experiments revealed that both IL17A and IL17F enhance cell-surface expression of transforming growth factor-ß receptor II and promote pro-fibrotic gene expression via the JUN pathway in human hepatic stellate cells. Our insights suggest that IL17A and IL17F share their pro-fibrotic function in the context of liver fibrosis, and moreover, dual blockade of IL17A and IL17F by anti-IL17RA Ab would be a promising strategy for the management of liver fibrosis.

Association of serum Ly6/PLAUR domain-containing protein 1 levels with skin sclerosis in systemic sclerosis.

Systemic sclerosis (SSc) is a connective tissue disease characterized by aberrant immune activation, vascular injury, and fibrosis of the skin and internal organs. Ly6/PLAUR domain-containing protein 1 (LYPD1) was reported to be secreted and to have various physiological functions such as anti-angiogenic effects. Here we investigated serum LYPD1 levels in SSc patients and the association of serum LYPD1 levels with clinical features of SSc. Serum samples were obtained from 75 SSc patients and 22 healthy individuals as controls. We measured serum LYPD1 levels using enzyme-linked immunosorbent assay kits. Then, the relationship between serum LYPD1 levels and clinical features of SSc was analyzed. Serum LYPD1 levels in diffuse cutaneous SSc (dcSSc) patients were significantly higher than those in the limited cutaneous SSc (lcSSc) patients (median [25-75th percentiles], 1693.43 [1086.61-1917.57] vs. 904.55 [714.356-1285.56] pg/mL), while there were no significant differences in the serum LYPD1 levels between lcSSc and healthy controls (904.55 [714.356-1285.56] vs. 750.71 pg/mL [544.00-912.14]). Further analysis revealed that serum LYPD1 levels in patients correlated with skin thickness scores and serum interleukin (IL)-6 levels, which were known to reflect the extent of skin thickening in SSc. Moreover, serum LYPD1 levels showed a decrease with improvement in skin thickness after treatment, along with a decrease in serum IL-6 levels. These results indicate that LYPD1 might be a potential marker for monitoring skin sclerosis and evaluating the efficacy of skin fibrosis treatment in SSc patients.

International exchange on the clinical practice and research of rheumatic skin diseases: A report of the 5th International Conference of Cutaneous Lupus Erythematosus.

The 5th International Conference of Cutaneous Lupus Erythematosus was held in Tokyo, Japan on May 9 and 10, 2023. The latest topics on the pathogenesis, diagnosis, assessment, and treatment of cutaneous lupus erythematosus, dermatomyositis, and scleroderma (systemic sclerosis, morphea) were presented by experts in each field and new developments discussed. In these rheumatic skin diseases, many clinical trials of novel therapies targeting cytokines, signaling molecules, plasmacytoid dendritic cells, B cells, and other molecules are currently underway, and standardization of outcome assessment was discussed. In addition, the selection of the therapeutic agents available for the diversity of each case is becoming more important, together with the ongoing pathophysiological analysis of the diseases. The achievements of this conference will further promote the development of clinical practice and research in rheumatic skin diseases through international exchange among researchers. We hope that by reporting a summary of the conference in this manuscript, we can share its contents with readers.

Hexafluoroisopropanol as a Bioconjugation Medium of Ultrafast, Tryptophan-Selective Catalysis.

The past decade has seen a remarkable growth in the number of bioconjugation techniques in chemistry, biology, material science, and biomedical fields. A core design element in bioconjugation technology is a chemical reaction that can form a covalent bond between the protein of interest and the labeling reagent. Achieving chemoselective protein bioconjugation in aqueous media is challenging, especially for generally less reactive amino acid residues, such as tryptophan. We present here the development of tryptophan-selective bioconjugation methods through ultrafast Lewis acid-catalyzed reactions in hexafluoroisopropanol (HFIP). Structure-reactivity relationship studies have revealed a combination of thiophene and ethanol moieties to give a suitable labeling reagent for this bioconjugation process, which enables modification of peptides and proteins in an extremely rapid reaction unencumbered by noticeable side reactions. The capability of the labeling method also facilitated radiofluorination application as well as antibody functionalization. Enhancement of an α-helix by HFIP leads to its compatibility with a certain protein, and this report also demonstrates a further stabilization strategy achieved by the addition of an ionic liquid to the HFIP medium. The nonaqueous bioconjugation approaches allow access to numerous chemical reactions that are unavailable in traditional aqueous processes and will further advance the chemistry of proteins.

The role of B cells in systemic sclerosis.

Systemic sclerosis (SSc) is a rare and refractory systemic disease characterized by fibrosis and vasculopathy in the presence of autoimmune abnormalities. While the exact cause of SSc is incompletely understood, the specific autoantibodies identified in SSc are closely linked to disease severity and prognosis, indicating a significant role of autoimmune abnormalities in the pathogenesis of SSc. Although the direct pathogenic mechanisms of autoantibodies in SSc are not fully elucidated, numerous prior investigations have demonstrated the involvement of B cells in the pathogenesis of SSc through various mechanisms. Additionally, several clinical trials have explored the efficacy of B-cell depletion therapy for SSc, with many reporting positive outcomes. However, the role of B cells in SSc pathogenesis is multifaceted, as they can both promote inflammation and exert inhibitory functions. This article provides an overview of the involvement of B cells in SSc development, incorporating the latest research findings.