Aberrant immune responses to viral pathogens contribute to pathogenesis, but our understanding of pathological immune responses caused by viruses within the human virome, especially at a population scale, remains limited. We analyzed whole-genome sequencing datasets of 6,321 Japanese individuals, including patients with autoimmune diseases (psoriasis vulgaris, rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), pulmonary alveolar proteinosis (PAP) or multiple sclerosis) and coronavirus disease 2019 (COVID-19), or healthy controls. We systematically quantified two constituents of the blood DNA virome, endogenous HHV-6 (eHHV-6) and anellovirus.
View Article and Find Full Text PDFMelanogenesis is a major part of the environmental responses and tissue development of the integumentary system. The balance between reduction and oxidation (redox) governs pigmentary responses, for which coordination among epidermal resident cells is indispensable. Here, we review the current understanding of melanocyte biology with a particular focus on the "master regulator" of oxidative stress responses (i.
View Article and Find Full Text PDFThe Kelch-like erythroid cell-derived protein with cap'n'collar homology-associated protein 1 (KEAP1)-nuclear factor erythroid-2-related factor 2 (NRF2) system, a thiol-based sensor-effector apparatus, exerts antioxidative and anti-inflammatory effects and maintains skin homeostasis. Thus, NRF2 activation appears to be a promising treatment option for various skin diseases. However, NRF2-mediated defense responses may deteriorate skin inflammation in a context-dependent manner.
View Article and Find Full Text PDFCornification is a specialized mode of the cell-death program exclusively allowed for terrestrial amniotes. Recent investigations suggest that loricrin (LOR) is an important cornification effector. As the connotation of its name ("lorica" meaning an armor in Latin) suggests, the keratin-associated protein LOR promotes the maturation of the epidermal structure through organizing covalent cross-linkages, endowing the epidermis with the protection against oxidative injuries.
View Article and Find Full Text PDFA functional epithelial barrier necessitates protection against dehydration, and ichthyoses are caused by defects in maintaining the permeability barrier in the stratum corneum (SC), the uppermost protective layer composed of dead cells and secretory materials from the living layer stratum granulosum (SG). We have found that loricrin (LOR) is an essential effector of cornification that occurs in the uppermost layer of SG (SG1). LOR promotes the maturation of corneocytes and extracellular adhesion structure through organizing disulfide cross-linkages, albeit being dispensable for the SC permeability barrier.
View Article and Find Full Text PDFCornification involves cytoskeletal cross-linkages in corneocytes (the brick) and the secretion of lipids/adhesion structures to the interstitial space (the mortar). Because the assembly of lipid envelopes precedes corneocyte maturation, loricrin is supposed to be dispensable for the protection against desiccation. Although the phenotypes of knockout (LKO) mice are obscure, the antioxidative response on the KEAP1/NRF2 signaling pathway compensates for the structural defect in utero.
View Article and Find Full Text PDFThe exact mechanisms of the imiquimod (IMQ)-induced antitumor effect have not been fully understood. Although both topical IMQ treatment and anti-PD-1 antibody may be used for primary skin lesions or skin metastases of various cancers, the efficacy of each monotherapy for these lesions is insufficient. Using a murine tumor model and human samples, we aimed to elucidate the detailed mechanisms of the IMQ-induced antitumor effect and analyzed the antitumor effect of combination therapy of topical IMQ plus anti-PD-1 antibody.
View Article and Find Full Text PDFBackground: The efficacy of small molecule inhibitors for intracellular signal mediators varies among the individuals, and their mechanism of action is broad. A phosphodiesterase 4 inhibitor apremilast shows a dramatic effect on a certain proportion of psoriatic patients by modulating the cellular metabolism and regulating the production of pro-inflammatory molecules. However, it is unclear to which disease subtype this drug benefits.
View Article and Find Full Text PDFPD-1 is an immunoregulatory receptor that can bind PD-L1 or PD-L2 expressed on stimulated antigen-presenting cells. In this study, isolated antigen-presenting cells (macrophages and dendritic cells) were cultured with IFN-γ, IL-4, or IL-17A, and the expression of PD-L1 and PD-L2 was compared by flow cytometry. Strong upregulation of PD-L1 expression was observed on IFN-γ stimulation of both antigen-presenting cells as well as in response to IL-17A stimulation of macrophages compared with the expression in unstimulated controls.
View Article and Find Full Text PDFSeveral studies have demonstrated the usefulness of negative pressure closure (NPC) for the stabilization of skin grafts because it provides a uniform pressure to the graft. The results of our previous retrospective study also suggested the superiority of NPC over tie-over methods for the stabilization of split-thickness skin graft (STSG) in large or muscle-exposing defects. However, the usefulness of NPC for graft stabilization is yet to be fully established.
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