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図書 |
図書
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edited by Makoto Maejima, Tokuzo Shiga
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論文 |
論文
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Imaizumi, Tadaatsu ; Mori, Fumiaki ; Yagihashi, Norito ; Kitamura, Hideo ; Sashinami, Hiroshi ; Suzuki, Koichi ; Yamashita, Koji ; Taima, Kageaki ; Kubota, Kosei ; Tanji, Kunikazu ; Sakaki, Hirotaka ; Matsumiya, Tomoh ; Yoshida, Hidemi ; Mariya, Yasushi ; Nakane, Hajime ; Tanaka, Hiroshi ; Takanashi, Shingo ; Wakabayashi, Koichi ; Yagihashi, Soroku ; Nakane, Akio ; Ito, Etsuro ; Okumura, Ken ; Kimura, Hiroto ; Satoh, Kei
概要:
Retinoic acid-inducible gene-I （RIG-I） is a cytoplasmic protein regarded as putative RNA helicase.Immunohistochemical st
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udies revealed high levels of RIG-I expression in epidermic cells in psoriasis, in macrophagesin atherosclerotic lesions and in glomeruli of lupus nephritis. RIG-I expression was also demonstrated in macrophagesand vascular endothelial cells in experimental animals with Listeria or Hanta virus infection. In vitro studies using cellcultures revealed the expression of RIG-I, in various cells including endothelial cells, macrophages and astroglial cells, inresponse to the stimulation with cytokines, lipopolysaccharide, double-stranded RNA, Listeria monocytogenes, etc. Thestudies employing the overexpression or RNA interference suggested that RIG-I is involved in the regulation of cytokineexpression including CXCL10/IP-10 and CCL5/RANTES. These results suggest that RIG-I constitutes a part of theintracellular pathway for the regulation of infl ammatory and immune responses.
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| 3.
論文 |
論文
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Imaizumi, Tadaatsu ; Aizawa, Tomomi ; Tanaka, Hiroshi ; Sato, Fuyuki ; Xing, Fei ; Matsumiya, Tomoh ; Yoshida, Hidemi ; Satoh, Kei
概要:
Viral infection is important in renal pathology both as a trigger of chronic inflammatory diseases and as a complicatio
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n associated with organ transplantation. Glomerular mesangial cells produce a variety of functional molecules potentially involved in immune reactions, and we investigated anti-viral responses in normal human mesangial cells. Human mesangial cells were treated with polyinosinic-polycytidylic acid （poly IC）, an authentic double-stranded RNA that mimics viral RNA. Treatment of cells with poly IC induced interferon-β （IFN-β）, retinoic acid-inducible gene-I（ RIG-I）, CC chemokine ligand 5（ CCL5）, differentiated embryo-chondrocyte 2（ DEC2） and IFN-stimulated gene 20 （ISG20）. Knockdown of toll-like receptor 3 （TLR3）, by RNA interference （RNAi）, abolished the poly IC-induced expression of these molecules. RNAi against IFN-β inhibited the induction of RIG-I,CCL5 and ISG20, but not of DEC2. Knockdown of RIG-I resulted in the reduced expression of CCL5. RNAi against DEC2 enhanced the poly IC-induced expression of IFN-β, RIG-I and CCL5. Transfection of cells with a poly IC/cationic lipid complex induced IFN-β, RIG-I and ISG20. Knockdown of RIG-I decreased the expression of IFN-β and ISG20 induced by transfection with poly IC/cationic lipid. TLR3 and RIG-I may function as recognition receptors against double-stranded RNA, which induce IFN-β and its downstream IFN-inducible genes. In the signaling elicited by poly IC, the IFN-inducible genes include RIG-I and effector molecules as CCL5 with leukocyte chemotactic activity and ISG20 with exonuclease activity on single-stranded RNA. The poly IC-induced expression of DEC2 is independent on IFN-β and it may control the signaling elicited by double-stranded RNA. The poly IC-inducible molecules may mediate anti-viral innate responses in renal mesangial cells.
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論文 |
論文
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Imaizumi, Tadaatsu ; Hayakari, Ryo ; Watanabe, Shojiro ; Aizawa, Tomomi ; Matsumiya, Tomoh ; Yoshida, Hidemi ; Tsuruga, Kazushi ; Kawaguchi, Shogo ; Tanaka, Hiroshi
概要:
Cylindromatosis (CYLD), a deubiquitinase, negatively regulates nuclear factor-κB in various cells. However, its potentia
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l roles in glomerular inflammation remain unclear. Because the activation of the Toll-like receptor 3 (TLR3)/type I interferon (IFN) pathways plays a pivotal role in chronic kidney diseases (CKD), we examined the role of CYLD in the TLR3 signaling in cultured human mesangial cells (MCs).<br />We stimulated CYLD-silenced MCs with polyinosinic-polycytidylic acid (poly IC), a synthetic analogue of dsRNA, and studied representative TLR3/IFN-β pathways (i.e., TLR3/IFN-β/retinoic acid-inducible gene-I (RIG-I)/CCL5, and TLR3/IFN-β/melanoma differentiation associated gene 5 (MDA5)/CXCL10 axes) using RT-PCR, western blotting, and ELISA. We also used immunofluorescence staining and microscopy to examine mesangial CYLD expression in biopsied specimens from patients with CKD.<br />CYLD silencing resulted in an increase of poly IC-induced RIG-I and MDA5 protein levels and increased CCL5 and CXCL10 mRNA and protein expression, but unexpectedly decreased mRNA expressions of RIG-I and MDA5. Interestingly, CYLD silencing did not affect IFN-β or the phosphorylated STAT1 (signal transducers and activator of transcription protein 1). CYLD was highly expressed in biopsied specimens from patients with proliferative lupus nephritis (LN).<br />CYLD inhibits post-transcriptional regulation of RIG-I and MDA5 expression following TLR3 activation in MCs. CYLD may be involved in the pathogenesis of CKD, especially pathogenesis of LN.
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| 5.
論文 |
論文
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Tanaka, Hiroshi ; Imaizumi, Tadaatsu
概要:
The innate and adaptive immune systems have been reported to play an important role in the pathogenesis of glomerular diseases. Since viral infections may trigger the development of inflammatory renal disease or the worsening of
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preexisting renal disease, recent studies have focused on the involvement of toll-like receptors (TLRs) and their signaling pathways in the inflammatory processes of glomerular cells. Viral double-stranded RNA (dsRNA) can activate not only TLR3 located within intracellular endosomes but also retinoic-acid-inducible-gene-I- (RIG-I-) like helicase receptors located within the cytosol. RIG-I and melanoma differentiation-associated gene 5 (MDA5) are members of the RNA helicase family in the cytosol, and both act as pathogen recognition receptors. The activation of TLRs and their downstream immune responses can be induced by both infectious pathogens and noninfectious stimuli such as endogenous ligands, and this mechanism may be involved in the pathogenesis of autoimmune renal diseases. However, there are few data on the interaction between TLR3, MDA5, and RIG-I in autoimmune glomerular diseases. Based on our recent experimental studies using cultured normal human mesangial cells (MCs), we found that novel TLR3-mediated signaling pathways in MCs may be involved in the pathogenesis of glomerular diseases. In the present paper, we summarize our recent findings.
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| 6.
論文 |
論文
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Imaizumi, Tadaatsu ; Yano, Chikashi ; Numata, Akiko ; Tsugawa, Koji ; Hayakari, Ryo ; Matsumiya, Tomoh ; Yoshida, Hidemi ; Watanabe, Shojiro ; Tsuruga, Kazushi ; Kawaguchi, Shogo ; Murakami, Manabu ; Tanaka, Hiroshi
概要:
Activation of Toll-like receptor 3 (TLR3) signaling followed by type I interferon (IFN) expression is crucial in antivir
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al and "pseudoviral" immune reactions in renal mesangial cells (MCs). These reactions are probably involved in the pathogenesis of chronic kidney disease (CKD). However, the role of IFN-induced 35-kDa protein 35 (IFI35), a type I IFN-dependent transcript, in glomerular inflammation is unclear. Here, we aimed to investigate the expression and the role of IFI35 in IFN-β/retinoic acid-inducible gene-I (RIG-I)/CCL5 and IFN-β/melanoma differentiation-associated gene 5 (MDA5)/CXCL10 axes in MCs.<br />We treated human MCs with polyinosinic-polycytidylic acid (poly IC), an authentic double-stranded RNA, then analysed the IFI35 expression by reverse transcription-polymerase chain reaction and western blotting. To examine the regulation of IFI35 expression, we subjected MCs to RNA interference (siRNA) against IFN-β, RIG-I, and MDA5.<br />Activation of TLR3 by poly IC induces the IFI35 expression in MCs. siRNA against IFN-β inhibited poly IC-induced IFI35 expression. Knockdown of IFI35 resulted in a decrease of poly IC-induced RIG-I and MDA5 protein as well as decreased CCL5 and CXCL10 mRNA and protein expression. However, it did not affect the expression of none of phosphorylated signal transducers or activator of transcription (STAT) 1 protein, or RIG-I and MDA5 in mRNA levels.<br />Regional expression of IFI35 and its dysregulation may be involved in the pathogenesis of glomerular inflammation in CKD.
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| 7.
論文 |
論文
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Aizawa, Tomomi ; Imaizumi, Tadaatsu ; Tsuruga, Kazushi ; Watanabe, Shojiro ; Yoshida, Hidemi ; Kumagai, Naonori ; Ito, Etsuro ; Tanaka, Hiroshi
概要:
Renal biopsy is the gold standard for confirmation of disease severity and diagnosis of glomerulonephritis (GN), but its procedure is invasive with a risk of complications. Thus, a non-invasive monitoring method is desirable especially
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in pediatric patients. Fractalkine and monocyte chemoattractant protein-1 (MCP-1) are proinflammatory chemokines, and both have been reported to be involved in the pathogenesis of immunocomplex-mediated GN. Recently, it has been reported that urinary fractalkine and MCP-1 may serve as possible predictors of disease activity of adult patients with GN. We, therefore, examined whether urinary levels of fractalkine and MCP-1 correlate with clinical and histologic parameters. Twenty-six consecutive children with various types of GN were enrolled in this study, including lupus nephritis, IgA nephropathy, membranous nephropathy, acute GN, and thin basement membrane disease (served as a non-inflammatory control). Urinary fractalkine and MCP-1 concentrations in the first morning urine samples obtained at the time of renal biopsy were measured by enzyme-linked immunosorbent assay, and standardized for urinary creatinine concentrations. Urinary fractalkine concentration differed significantly among the disease categories. Urinary concentrations of fractalkine and MCP-1 showed a significant positive correlation with the degree of occult blood in urine and a significant inverse correlation with the estimated glomerular filtration rate. Furthermore, the urinary MCP-1 concentration was significantly correlated with histological chronicity indices in patients with lupus nephritis and IgA nephropathy. Measurement of urinary fractalkine and MCP-1 concentrations may be useful as a non-invasive method for predicting the disease activity of GN in children.
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