Toll-like receptor 4 (TLR4) and matrix metalloproteinase-9 (MMP-9) are known to play important roles in inflammatory diseases such as arteriosclerosis and plaque instability. The purpose of this study was to perform the effect of 4-O-carboxymethylascochlorin (AS-6) on MMP-9 expression in lipopolysaccharide (LPS)-induced murine macrophages and signaling pathway involved in its anti-inflammatory effect. Effect of AS-6 on MAPK/NF-κB/TLR4 signaling pathway in LPS-activated murine macrophages was examined using ELISA, Western blotting, reverse transcription polymerase chain reaction (RT-PCR) and fluorescence immunoassay. MMP-9 enzyme activity was examined by gelatin zymography. AS-6 significantly suppressed MMP-9 and MAPK/NF-κB expression levels in LPS-stimulated murine macrophages. Expression levels of inducible nitric oxide synthase (iNOS), COX2, MMP-9, JNK, ERK, p38 phosphorylation, and NF-κB stimulated by LPS were also decreased by AS-6. Moreover, AS-6 suppressed TLR4 expression and dysregulated LPS-induced activators of transcription signaling pathway. The results of this study showed that AS-6 can inhibit LPS-stimulated inflammatory response by suppressing TLR4/MAPK/NF-κB signals, suggesting that AS-6 can be used to induce the stability of atherosclerotic plaque and prevent inflammatory diseases in an in vitro model.
The study evaluated the anticomplement activity from various solvent extracts of nine Amarantaceae plants (Achyranthes japonica (Miq.) Nakai, Amaranthus mangostanus L., Amaranthus retroflexus L., Amaranthus spinosus L., Celosia argentea var. spicata., Amaranthus lividus L., Celosia cristata L., Amaranthus viridis L., Gomphrena globosa L.) from South Korea on the classical pathway. We have evaluated various organic solvent extract from nine Amarantaceae plants with regard to its anticomplement activity on the classical pathway. Achyranthes japonica chloroform extracts showed inhibitory activity against complement system with 50% inhibitory concentrations (IC(50)) value of 73.1μg/ml. This is the first report of anticomplement activity from Amarantaceae plants.
// Sun-Hyung Ha 1, * , Sung-Koo Kang 1, * , Hyunju Choi 1 , Choong-Hwan Kwak 1 , Fukushi Abekura 1 , Jun-Young Park 1 , Kyung-Min Kwon 1, 2 , Hyeun-Wook Chang 3 , Young-Choon Lee 4 , Ki-Tae Ha 5 , Bo Kyeng Hou 6 , Tae-Wook Chung 5 and Cheorl-Ho Kim 1, 7 1 Molecular and Cellular Glycobiology Unit, Department of Biological Sciences, SungKyunKwan University, Seoburo, Jangan-Gu, Kyunggi-Do, Korea 2 Research Institute, Davinch-K Co., Ltd., Geumcheon-gu, Seoul, Korea 3 College of Pharmacy, Yeungnam University, Gyeongsan, Korea 4 Faculty of Medicinal Biotechnology, Dong-A University, Busan, Korea 5 Division of Applied Medicine, School of Korean Medicine, Pusan National University, Yangsan City, Gyeongsangnam-Do, Korea 6 Korean Bioinformation Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea 7 Department of Medical Device Management and Research, Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University, Seoul, Korea * These authors contributed equally to this work and share co-first authors Correspondence to: Cheorl-Ho Kim, email: chkimbio@skku.edu Tae-Wook Chung, email: twchung@pusan.ac.kr Keywords: adrenergic receptor, transglutaminase 2, ganglioside GD3, erythroid differentiation, human chronic myelogenous leukemia K562 cell Received: July 05, 2016 Accepted: July 18, 2017 Published: August 09, 2017 ABSTRACT The disialic acid-containing glycosphingolipid GD3 recruited membrane transglutaminase 2 (TG2) as a signaling molecule for erythroid differentiation in human chronic myelogenous leukemia (CML) K562 cells. The α1-adrenergic receptor (α1-AR)/TG2-mediated signaling pathway regulated GD3 functions, including gene expression and production, to differentiate CML K562 cells into erythroid lineage cells. Epinephrine, an AR agonist, increased membrane recruitment as well as GTP-photoaffinity of TG2, inducing GD3 synthase gene expression. Epinephrine activated PI3K/Akt signaling and GTPase downstream of TG2 activated Akt. The coupling of TG2 and GD3 production was specifically suppressed by prazosin (α1-AR antagonist), but not by propranolol (β-AR antagonist) or rauwolscine (α2-AR antagonist), indicating α1-AR specificity. Small interfering RNA (siRNA) experiment results indicated that the α1-AR/TG2-mediated signaling pathway activated PKCs α and δ to induce GD3 synthase gene expression. Transcription factors CREB, AP-1, and NF-κB regulated GD3 synthase gene expression during α1-AR-induced differentiation in CML K562 cells. In addition, GD3 synthase gene expression was upregulated in TG2-transfected cells via α1-AR with expression of erythroid lineage markers and benzidine-positive staining. α1-AR/TG2 signaling pathway-directed GD3 production is a crucial step in erythroid differentiation of K562 cells and GD3 interacts with α1-AR/TG2, inducing GD3/α1-AR/TG2-mediated erythroid differentiation. These results suggest that GD3, which acts as a membrane mediator of erythroid differentiation in CML cells, provides a therapeutic avenue for leukemia treatment.
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