Spred2-deficiency enhances the proliferation of lung epithelial cells and alleviates pulmonary fibrosis induced by bleomycin

The mitogen-activated protein kinase (MAPK) pathways are involved in many cellular processes, including the development of fibrosis. Here, we examined the role of Sprouty-related EVH-1-domain-containing protein (Spred) 2, a negative regulator of the MAPK-ERK pathway, in the development of bleomycin (BLM)-induced pulmonary fibrosis (PF). Compared to WT mice, Spred2−/− mice developed milder PF with increased proliferation of bronchial epithelial cells. Spred2−/− lung epithelial cells or MLE-12 cells treated with spred2 siRNA proliferated faster than control cells in vitro. Spred2−/− and WT macrophages produced similar levels of TNFα and MCP-1 in response to BLM or lipopolysaccharide and myeloid cell-specific deletion of Spred2 in mice had no effect. Spred2−/− fibroblasts proliferated faster and produced similar levels of MCP-1 compared to WT fibroblasts. Spred2 mRNA was almost exclusively detected in bronchial epithelial cells of naïve WT mice and it accumulated in approximately 50% of cells with a characteristic of Clara cells, 14 days after BLM treatment. These results suggest that Spred2 is involved in the regulation of tissue repair after BLM-induced lung injury and increased proliferation of lung bronchial cells in Spred2−/− mice may contribute to faster tissue repair. Thus, Spred2 may present a new therapeutic target for the treatment of PF

柿タンニンは新型コロナウイルスに対する抗ウイルス効果を持ち、シリアンハムスターモデルにおける新型コロナウイルス感染症の重症度および感染伝播を抑制する

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread across the world. Inactivating the virus in saliva and the oral cavity represents a reasonable approach to prevent human-to-human transmission because the virus is easily transmitted through oral routes by dispersed saliva. Persimmon-derived tannin is a condensed type of tannin that has strong antioxidant and antimicrobial activity. In this study, we investigated the antiviral effects of persimmon-derived tannin against SARS-CoV-2 in both in vitro and in vivo models. We found that persimmon-derived tannin suppressed SARS-CoV-2 titers measured by plaque assay in vitro in a dose- and time-dependent manner. We then created a Syrian hamster model by inoculating SARS-CoV-2 into hamsters' mouths. Oral administration of persimmon-derived tannin dissolved in carboxymethyl cellulose before virus inoculation dramatically reduced the severity of pneumonia with lower virus titers compared with a control group inoculated with carboxymethyl cellulose alone. In addition, pre-administration of tannin to uninfected hamsters reduced hamster-to-hamster transmission of SARS-CoV-2 from a cohoused, infected donor cage mate. These data suggest that oral administration of persimmon-derived tannin may help reduce the severity of SARS-CoV-2 infection and transmission of the virus.博士（医学）・甲第817号・令和4年3月15日© 2021. The Author(s). Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/

Dietary Phenolic Compounds: Their Health Benefits and Association with the Gut Microbiota

Oxidative stress causes various diseases, such as type II diabetes and dyslipidemia, while antioxidants in foods may prevent a number of diseases and delay aging by exerting their effects in vivo. Phenolic compounds are phytochemicals such as flavonoids which consist of flavonols, flavones, flavanonols, flavanones, anthocyanidins, isoflavones, lignans, stilbenoids, curcuminoids, phenolic acids, and tannins. They have phenolic hydroxyl groups in their molecular structures. These compounds are present in most plants, are abundant in nature, and contribute to the bitterness and color of various foods. Dietary phenolic compounds, such as quercetin in onions and sesamin in sesame, exhibit antioxidant activity and help prevent cell aging and diseases. In addition, other kinds of compounds, such as tannins, have larger molecular weights, and many unexplained aspects still exist. The antioxidant activities of phenolic compounds may be beneficial for human health. On the other hand, metabolism by intestinal bacteria changes the structures of these compounds with antioxidant properties, and the resulting metabolites exert their effects in vivo. In recent years, it has become possible to analyze the composition of the intestinal microbiota. The augmentation of the intestinal microbiota by the intake of phenolic compounds has been implicated in disease prevention and symptom recovery. Furthermore, the “brain–gut axis”, which is a communication system between the gut microbiome and brain, is attracting increasing attention, and research has revealed that the gut microbiota and dietary phenolic compounds affect brain homeostasis. In this review, we discuss the usefulness of dietary phenolic compounds with antioxidant activities against some diseases, their biotransformation by the gut microbiota, the augmentation of the intestinal microflora, and their effects on the brain–gut axis

Antioxidant Potential of Non-Extractable Fractions of Dried Persimmon (<i>Diospyros kaki</i> Thunb.) in Streptozotocin-Induced Diabetic Rats

Oxidative stress causes the progression of diabetes and its complications; thus, maintaining the balance between reactive oxygen species produced by hyperglycemia and the antioxidant defense system is important. We herein examined the antioxidant potential of non-extractable fractions of dried persimmon (NEP) against oxidative stress in diabetic rats. Rats with streptozotocin-induced type 1 diabetes (50 mg/kg body weight) were administered NEP for 9 weeks. Antioxidant enzyme activities and concentration of antioxidants in liver tissues were analyzed with a microplate reader. Extensor digitorum longus (EDL) and soleus muscle fibers were stained with succinate dehydrogenase and muscle fiber sizes were measured. The administration of NEP increased the body weight of diabetes rats. Regarding antioxidant activities, the oxygen radical absorbance capacity and superoxide dismutase activity in liver tissues significantly increased. In addition, increases in glutathione peroxidase activity in liver tissues and reductions in the cross-sectional area of EDL muscle fibers were significantly suppressed. In these results, NEP improved the antioxidant defense system in the liver tissues of diabetic rats, in addition to attenuating of muscle fibers atrophy against oxidative damage induced by hyperglycemia

ヒト脂肪由来間葉型幹細胞は、間葉上皮転換によりエラスターゼ誘発マウス肺気腫を改善する

Purpose: Chronic obstructive pulmonary disease (COPD) is a worldwide problem because of its high prevalence and mortality. However, there is no fundamental treatment to ameliorate their pathological change in COPD lung. Recently, adipose-derived mesenchymal stem cells (ADSCs) have attracted attention in the field of regenerative medicine to repair damaged organs. Moreover, their utility in treating respiratory diseases has been reported in some animal models. However, the detailed mechanism by which ADSCs improve chronic respiratory diseases, including COPD, remains to be elucidated. We examined whether human ADSCs (hADSCs) ameliorated elastase-induced emphysema and whether hADSCs differentiated into alveolar epithelial cells in a murine model of COPD. Methods: Female SCID-beige mice (6 weeks old) were divided into the following four groups according to whether they received an intratracheal injection of phosphate-buffered saline or porcine pancreatic elastase, and whether they received an intravenous injection of saline or hADSCs 3 days after intratracheal injection; Control group, hADSC group, Elastase group, and Elastase-hADSC group. We evaluated the lung function, assessed histological changes, and compared gene expression between hADSCs isolated from the lung of Elastase-hADSC group and naïve hADSCs 28 days after saline or elastase administration. Results: hADSCs improved the pathogenesis of COPD, including the mean linear intercept and forced expiratory volume, in an elastase-induced emphysema model in mice. Furthermore, hADSCs were observed in the lungs of elastase-treated mice at 25 days after administration. These cells expressed genes related to mesenchymal-epithelial transition and surface markers of alveolar epithelial cells, such as TTF-1, β-catenin, and E-cadherin. Conclusion: hADSCs have the potential to improve the pathogenesis of COPD by differentiating into alveolar epithelial cells by mesenchymal-epithelial transition.博士（医学）・甲第825号・令和4年3月15日© 2021 Fujioka et al. This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms. php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms (https://www.dovepress.com/terms.php)

Silencing of Carbohydrate Sulfotransferase 15 Hinders Murine Pulmonary Fibrosis Development

Pulmonary fibrosis is a progressive lung disorder characterized by interstitial fibrosis, for which no effective treatments are available. Chondroitin sulfate proteoglycan (CSPG) has been shown to be a mediator, but the specific component of glycosaminoglycan chains of CSPG has not been explored. We show that chondroitin sulfate E-type (CS-E) is involved in fibrogenesis. Small interfering RNA (siRNA) targeting carbohydrate sulfotransferase 15 (CHST15) was designed to inhibit CHST15 mRNA and its product, CS-E. CS-E augments cell contraction and CHST15 siRNA inhibits collagen production. We found that bleomycin treatment increased CHST15 expression in interstitial fibroblasts at day 14. CHST15 siRNA was injected intranasally on days 1, 4, 8, and 11, and CHST15 mRNA was significantly suppressed by day 14. CHST15 siRNA reduced lung CSPG and the grade of fibrosis. CHST15 siRNA repressed the activation of fibroblasts, as evidenced by suppressed expression of α smooth muscle actin (αSMA), connective tissue growth factor (CTGF), lysyl oxidase like 2 (LOXL2), and CC-chemokine ligand 2 (CCL2)/monocyte chemoattractant protein-1 (MCP-1). Inflammatory infiltrates in the bronchoalveolar lavage fluid (BALF) and interstitium were diminished by CHST15 siRNA. These results indicate a pivotal role for CHST15 in fibroblast-mediated lung fibrosis and suggest a possible new therapeutic role for CHST15 siRNA in pulmonary fibrosis. Keywords: bleomycin, chondroitin sulfate proteoglycans, pulmonary fibrosis, macrophages, fibroblasts, chondroitin sulfate, idiopathic pulmonary fibrosi

Abrogated Caveolin-1 expression via histone modification enzyme Setdb2 regulates brain edema in a mouse model of influenza-associated encephalopathy

Abstract Influenza-associated encephalopathy (IAE) is a serious complication that can follow influenza virus infection. Once a cytokine storm is induced during influenza virus infection, tight junction protein disruption occurs, which consequently leads to blood-brain barrier (BBB) breakdown. However, the details of IAE pathogenesis are not well understood. Here, we established a murine IAE model by administration of lipopolysaccharide following influenza virus infection. Brains from IAE model mice had significantly higher expression of type I interferons and inflammatory cytokines. In addition, the expression of Caveolin-1, one of the key proteins that correlate with protection of the BBB, was significantly lower in brains from the IAE group compared with the control group. We also found that, among 84 different histone modification enzymes, only SET domain bifurcated 2 (Setdb2), one of the histone methyltransferases that methylates the lysine 9 of histone H3, showed significantly higher expression in the IAE group compared with the control group. Furthermore, chromatin immunoprecipitation revealed that methylation of histone H3 lysine 9 was correlated with repression of the Caveolin-1 promoter region. These studies identify Caveolin-1 as a key regulator of BBB permeability in IAE and reveal that it acts through histone modification induced by Setdb2

Responses of perivascular macrophages to circulating lipopolysaccharides in the subfornical organ with special reference to endotoxin tolerance

Abstract Background Circulating endotoxins including lipopolysaccharides (LPS) cause brain responses such as fever and decrease of food and water intake, while pre-injection of endotoxins attenuates these responses. This phenomenon is called endotoxin tolerance, but the mechanisms underlying it remain unclear. The subfornical organ (SFO) rapidly produces proinflammatory cytokines including interleukin-1β (IL-1β) in response to peripherally injected LPS, and repeated LPS injection attenuates IL-1β production in the SFO, indicating that the SFO is involved in endotoxin tolerance. The purpose of this study is to investigate features of the IL-1β source cells in the SFO of LPS-non-tolerant and LPS-tolerant mice. Methods We first established the endotoxin-tolerant mouse model by injecting LPS into adult male mice (C57BL/6J). Immunohistochemistry was performed to characterize IL-1β-expressing cells, which were perivascular macrophages in the SFO. We depleted perivascular macrophages using clodronate liposomes to confirm the contribution of IL-1β production. To assess the effect of LPS pre-injection on perivascular macrophages, we transferred bone marrow-derived cells obtained from male mice (C57BL/6-Tg (CAG-EGFP)) to male recipient mice (C57BL/6N). Finally, we examined the effect of a second LPS injection on IL-1β expression in the SFO perivascular macrophages. Results We report that perivascular macrophages but not parenchymal microglia rapidly produced the proinflammatory cytokine IL-1β in response to LPS. We found that peripherally injected LPS localized in the SFO perivascular space. Depletion of macrophages by injection of clodronate liposomes attenuated LPS-induced IL-1β expression in the SFO. When tolerance developed to LPS-induced sickness behavior in mice, the SFO perivascular macrophages ceased producing IL-1β, although bone marrow-derived perivascular macrophages increased in number in the SFO and peripherally injected LPS reached the SFO perivascular space. Conclusions The current data indicate that perivascular macrophages enable the SFO to produce IL-1β in response to circulating LPS and that its hyporesponsiveness may be the cause of endotoxin tolerance