Publications by authors named "Ryosuke Saigusa"

Article Synopsis
  • IgMs produced by a specific subtype of B cells protect against inflammation and diet-induced atherosclerosis by inactivating harmful lipid oxidation products.
  • This study identifies human marginal zone B (MZB) cells as the main source of these protective IgMs through advanced techniques like single-cell mass cytometry and testing in humanized mice.
  • Treatment that reduces MZB cells leads to increased vascular inflammation, showing their protective role, while findings also indicate that higher MZB cell presence correlates with less severity in coronary artery disease in patients.
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Coronary artery disease (CAD) is a major cause of death worldwide. The role of CD8+ T cells in CAD is unknown. Recent studies suggest a breakdown of tolerance in atherosclerosis, resulting in active T cell receptor (TCR) engagement with self-antigens.

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Femoral atherosclerotic plaques are less inflammatory than carotid plaques histologically, but limited cell-level data exist regarding comparative immune landscapes and polarization at these sites. We investigated intraplaque leukocyte phenotypes and transcriptional polarization in 49 patients undergoing femoral (n = 23) or carotid (n = 26) endarterectomy using single-cell RNA-Seq (scRNA-Seq; n = 13), flow cytometry (n = 24), and IHC (n = 12). Comparative scRNA-Seq of CD45+-selected leukocytes from femoral (n = 9; 35,265 cells) and carotid (n = 4; 30,655 cells) plaque revealed distinct transcriptional profiles.

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Despite the decades-old knowledge that males and people with diabetes mellitus (DM) are at increased risk for coronary artery disease (CAD), the reasons for this association are only partially understood. Among the immune cells involved, recent evidence supports a critical role of T cells as drivers and modifiers of CAD. CD4+ T cells are commonly found in atherosclerotic plaques.

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Background: Cryopreserved peripheral blood mononuclear cells (PBMCs) are frequently collected and provide disease- and treatment-relevant data in clinical studies. Here, we developed combined protein (40 antibodies) and transcript single-cell (sc)RNA sequencing (scRNA-seq) in PBMCs.

Results: Among 31 participants in the Women's Interagency HIV Study (WIHS), we sequenced 41,611 cells.

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Atherosclerosis is accompanied by a CD4 T cell response to apolipoprotein B (APOB). Major Histocompatibility Complex (MHC)-II tetramers can be used to isolate antigen-specific CD4 T cells by flow sorting. Here, we produce, validate and use an MHC-II tetramer, DRB1*07:01 APOB-p18, to sort APOB-p18-specific cells from peripheral blood mononuclear cell samples from 8 DRB1*07:01+ women with and without subclinical cardiovascular disease (sCVD).

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The transcriptomic information obtained by single cell RNA sequencing (scRNA-seq) can be supplemented by information on the cell surface phenotype by using oligonucleotide-tagged monoclonal antibodies (scAb-Seq). This is of particular importance in immune cells, where the correlation between mRNA and cell surface expression is very weak. scAb-Seq is facilitated by the availability of commercial antibodies and antibody mixes.

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Atherosclerosis is a chronic, lipid-driven disease of medium sized arteries which causes myocardial infarction and stroke. Recently, an adaptive immune response against the plaque-associated autoantigen Apolipoprotein B100 (ApoB), the structural protein component of low-density lipoprotein, has been implicated in atherogenesis. In healthy individuals, CD4 T cells responding to ApoB mainly comprised regulatory T cells, which confer immune tolerance and atheroprotection.

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Recent studies have suggested that IgE sensitization to α-gal is associated with coronary artery disease (CAD). However, the B cell subtype(s) responsible for production of IgE to α-gal and mechanisms mediating this production remain elusive. Single cell multi-omics sequencing, was utilized to phenotype B cells obtained from 60 subjects that had undergone coronary angiography in whom serum IgE was evaluated by ImmunoCAP.

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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.

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Background: Aldehyde dehydrogenase 1 family member A1 (RALDH1)-producing dermal dendritic cells (DCs), a conventional DC subset regulating skin fibrosis, are decreased in the involved skin of patients with systemic sclerosis (SSc). In this study, we investigated the contribution of Fli1 deficiency, a potential predisposing factor of SSc, to the phenotypical alteration of RALDH1-producing dermal DCs by using SSc model mice and SSc skin samples.

Methods: Bleomycin (BLM)-induced skin fibrosis was generated with Fli1 and wild-type mice.

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Rolling neutrophils form tethers with submicron diameters. Here, we report that these tethers detach, forming elongated neutrophil-derived structures (ENDS) in the vessel lumen. We studied ENDS formation in mice and humans in vitro and in vivo.

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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.

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Objective: In prevous studies, we established a new animal model, KLF5 ;Fli-1 mice, in which fundamental pathologic features of systemic sclerosis (SSc) are broadly recapitulated. SSc vasculopathy is believed to occur as a result of impaired vascular remodeling, but its detailed mechanism of action remains unknown. To address this, the present study investigated the properties of dermal microvascular endothelial cells (DMECs), bone marrow-derived endothelial progenitor cells (BM-EPCs), and bone marrow-derived mesenchymal stem cells (BM-MSCs), a precursor of pericytes, in KLF5 ;Fli-1 mice.

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Article Synopsis
  • - Cathepsin S (CTSS) is a key enzyme involved in various biological processes related to immune response and tissue remodeling, which are important in systemic sclerosis (SSc).
  • - A study found that serum CTSS levels are lower in patients with diffuse cutaneous SSc compared to those with limited cutaneous SSc and healthy individuals; this decrease is particularly notable in those with Raynaud's phenomenon and interstitial lung disease (ILD).
  • - The findings indicate that lower CTSS levels may contribute to the severity of ILD in SSc patients, as there is a negative correlation between CTSS levels and certain lung-related biomarkers, although it doesn't correlate with skin thickness or some lung function measurements.
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Endothelial dysfunction is a hallmark of vasculopathy associated with systemic sclerosis (SSc). Reactive hyperemia peripheral arterial tonometry is a rapid and non-invasive technique to assess peripheral microvascular endothelial function by measuring changes in digital pulse volume during reactive hyperemia. Low scores of the reactive hyperemia index (RHI) imply an impaired vasodilatory response and, accordingly, impaired endothelial and vascular health.

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Atherosclerosis is a chronic inflammatory disease of the arterial wall and the primary underlying cause of cardiovascular disease. Data from in vivo imaging, cell-lineage tracing and knockout studies in mice, as well as clinical interventional studies and advanced mRNA sequencing techniques, have drawn attention to the role of T cells as critical drivers and modifiers of the pathogenesis of atherosclerosis. CD4 T cells are commonly found in atherosclerotic plaques.

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Background: Skin fibrosis of systemic sclerosis (SSc) is believed to be driven by complex processes including immune abnormalities, but the underlying immune response remains enigmatic. In particular, the role of dermal dendritic cells (DCs) is totally unknown.

Objective: We investigated the impact of CD103 loss on bleomycin-induced skin fibrosis because CD103 is a critical molecule determining DC phenotypes.

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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.

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CXCL14 serves as a chemoattractant for activated macrophages, immature dendritic cells and natural killer cells, as well as an antiangiogenic factor by preventing the migration of endothelial cells. CXCL14 also exerts an inhibitory effect on the CXCL12/CXCR4 signaling pathway, which is involved in the maintenance of T-helper (Th)2 bias, and promotes Th1 immune response under the physiological and pathological conditions. Because CXCL14-mediated biological processes seem to be involved in the development of systemic sclerosis (SSc), which is characterized by Th2/Th17-skewed immune polarization and impaired neovascularization, we investigated the clinical correlation of serum CXCL14 levels in patients with this disease.

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Systemic sclerosis (SSc) is a multisystem connective tissue disease characterized by three cardinal pathological features, such as autoimmunity/inflammation, vasculopathy and extensive organ fibrosis. Therefore, numerous interests have been put on the roles of immune cells, vascular cells (endothelial cells and pericytes/vascular smooth muscle cells) and interstitial fibroblasts as well as their precursors in the field of SSc research. However, recent studies with clinical samples and animal models have drawn much attention to the potential role of epithelial cells as a member of critical drivers and/or modifiers in the pathogenesis of SSc.

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