• Molecules and Cells
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• v.42 no.1
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• pp.1-7
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• 2019

Macrophage is an important innate immune cell that not only initiates inflammatory responses, but also functions in tissue repair and anti-inflammatory responses. Regulating macrophage activity is thus critical to maintain immune homeostasis. Tyro3, Axl, and Mer are integral membrane proteins that constitute TAM family of receptor tyrosine kinases (RTKs). Growing evidence indicates that TAM family receptors play an important role in anti-inflammatory responses through modulating the function of macrophages. First, macrophages can recognize apoptotic bodies through interaction between TAM family receptors expressed on macrophages and their ligands attached to apoptotic bodies. Without TAM signaling, macrophages cannot clear up apoptotic cells, leading to broad inflammation due to over-activation of immune cells. Second, TAM signaling can prevent chronic activation of macrophages by attenuating inflammatory pathways through particular pattern recognition receptors and cytokine receptors. Third, TAM signaling can induce autophagy which is an important mechanism to inhibit NLRP3 inflammasome activation in macrophages. Fourth, TAM signaling can inhibit polarization of M1 macrophages. In this review, we will focus on mechanisms involved in how TAM family of RTKs can modulate function of macrophage associated with anti-inflammatory responses described above. We will also discuss several human diseases related to TAM signaling and potential therapeutic strategies of targeting TAM signaling.

• Journal of Microbiology and Biotechnology
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• v.32 no.11
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• pp.1406-1415
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• 2022

The formation of macrophage foam cells stimulated by oxidized low-density lipoprotein (ox-LDL) is deemed an important cause of atherosclerosis. Transcription factor Yin Yang 1 (YY1), which is a universally expressed multifunctional protein, is closely related to cell metabolism disorders such as lipid metabolism, sugar metabolism, and bile acid metabolism. However, whether YY1 is involved in macrophage inflammation and lipid accumulation still remains unknown. After mouse macrophage cell line RAW264.7 cells were induced by ox-LDL, YY1 and proprotein convertase subtilisin/kexin type 9 (PCSK9) expressions were found to be increased while low-density lipoprotein receptor (LDLR) expression was lowly expressed. Subsequently, through reverse transcription-quantitative polymerase chain reaction (RT-qPCR), Western blot analysis, Oil Red O staining and cholesterol quantification, it turned out that silencing of YY1 attenuated the inflammatory response and lipid accumulation in RAW264.7 cells caused by ox-LDL. Moreover, results from the JASPAR database, chromatin immunoprecipitation (ChIP) assay, luciferase reporter assay and Western blot analysis suggested that YY1 activated PCSK9 by binding to PCSK9 promoter and modulated the expression of LDLR in the downstream of PCSK9. In addition, the results of functional experiments demonstrated that the inhibitory effects of YY1 interference on ox-LDL-mediated macrophage inflammation and lipid accumulation were reversed by PCSK9 overexpression. To sum up, YY1 depletion inhibited its activation of PCSK9, thereby reducing cellular inflammatory response, cholesterol homeostasis imbalance, and lipid accumulation caused by ox-LDL.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.7
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• pp.1079-1083
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• 2015

Activating macrophage cells play an important role in the host immune defense system. In this paper, immuno-modulatory activities of polysaccharides separated from Jubak (JPS) in macrophage cells were investigated. Immuno-modulatory activities were estimated based on cell proliferation, nitric oxide (NO) and cytokine production, degree of mitogen-activated protein kinases (MAPKs), and nuclear factor (NF)-${\kappa}B$ phosphorylation in RAW264.7 macrophage cells. JPS (62.5 to $250{\mu}g/mL$) did not induce a cytotoxic event. Additionally, NO and proinflammatory cytokines (tumor necrosis factor-${\alpha}$ and interleukin-6) production significantly increased in a dose-dependent manner. Similarly, phosphorylation of MAPKs and NF-${\kappa}B$ increased upon JPS treatment. Therefore, our results suggest that polysaccharides separated from Jubak can induce macrophage activation through MAPK and NF-${\kappa}B$ signaling and induction of Th1 polarization.

• Journal of Korean Neurosurgical Society
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• v.55 no.5
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• pp.237-243
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• 2014

Objective : Symptomatic disc degeneration develops from inflammatory reactions in the annulus fibrosus (AF). Although inflammatory mediators during annular inflammation have been studied, the roles of matrix metalloproteinases (MMPs) and their inhibitors have not been fully elucidated. In this study, we evaluated the production of MMPs and tissue inhibitors of metalloproteinase (TIMPs) during annular inflammation using an in vitro co-culture system. We also examined the effect of notochordal cells on annular inflammation. Methods : Human AF (hAF) pellet was co-cultured for 48 hours with phorbol myristate acetate-stimulated macrophage-like THP-1 cells. hAF pellet and conditioned media (CM) from co-cultured cells were assayed for MMPs, TIMPs, and insulin-like growth factor (IGF)-1 levels using real-time reverse-transcriptase polymerase chain reaction and enzyem-linked immunosorbent assay. To evaluate whether notochordal cells affected MMPs or TIMPs production on annular inflammation, hAF co-cultured with notochordal cells from adult New Zealand White rabbits, were assayed. Results : MMP-1, -3, -9; and TIMP-1 levels were significantly increased in CM of hAF co-cultured with macrophage-like cells compared with hAF alone, whereas TIMP-2 and IGF-1 levels were significantly decreased (p<0.05). After macrophage exposure, hAF produced significantly more MMP-1 and -3 and less TIMP-1 and -2. Interleukin-$1{\beta}$ stimulation enhanced MMP-1 and -3 levels, and significantly diminished TIMP-2 levels. Co-culturing with rabbit notochordal cells did not significantly influence MMPs and TIMPs production or COL1A2 gene expression. Conclusion : Our results indicate that macrophage-like cells evoke annular degeneration through the regulation of major degradative enzymes and their inhibitors, produced by hAF, suggesting that the selective regulation of these enzymes provides future targets for symptomatic disc degeneration therapy.

• The Journal of Korean Obstetrics and Gynecology
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• v.23 no.3
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• pp.91-100
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• 2010

Purpose: The purpose of this study was to investigate the effects of Prunellae Spica Water Extract(PSE) on immune response in macrophage cells. Methods: We had devided two group the one is normal group; not treated with PSE, and the other is experimental group; treated with PSE. We measured the cell viability of PSE on RAW 264.7 cells and investigated production of nitric oxide(NO) and cytokines such as interleukin(IL)-$1{\beta}$, IL-6 and tumor necrosis factor (TNF)-$\alpha$ with sample PSE. Results: 1. Cell viability of PSE on RAW 264.7 cells was significantly decreased in both 24 hr and 48 hr incubation. 2. NO production of PSE on RAW 264.7 cells was significantly increased in both 24 hr and 48 hr incubation. 3. IL-$1{\beta}$ production of PSE on RAW 264.7 cells was significantly increased under concentration over $50\;{\mu}g/m{\ell}$ in 24 hr incubation. 4. IL-6 production of PSE on RAW 264.7 cells was significantly increased under concentration over $50\;{\mu}g/m{\ell}$ in 24 hr incubation. 5. TNF-$\alpha$ production of PSE on RAW 264.7 cells was significantly increased under concentration over $50\;{\mu}g/m{\ell}$ in 24 hr incubation. Conclusion: NO, IL-$1{\beta}$, IL-6 and TNF-$\alpha$ production of PSE on RAW 264.7 cells was significantly increased. This study suggest that PSE stimulates the macrophage and enhances the immune response.

• Journal of the Korean Society of Visualization
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• v.15 no.3
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• pp.41-46
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• 2017

The apoptosis of macrophages occurs throughout all stages of atherosclerosis. It is known to constitute atheromatous plaque, increase plaque instability, and thus contribute to the development of atherosclerosis. However, there still remains much to be elucidated on how the apoptotic macrophages affect the endothelial cells and also how they contribute to the development of atherosclerosis. Here we present a microfluidic system, which enables co-culture of apoptotic macrophages and endothelial cells in fibrin gel that mimics in vivo extracellular matrix. With the system, we can investigate the effect of macrophage apoptosis on vascular endothelial cells by quantitatively analyzing the level of reactive oxygen species of HUVECs, integrity of VE-cadherin and cell proliferation. We expect that this system could be utilized further for understanding different mechanisms of apoptotic macrophage on the development of atherosclerosis.

• Biomolecules & Therapeutics
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• v.21 no.1
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• pp.72-78
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• 2013

This work aimed to assess some pharmacological activities of P. leptostachya var. asiatica Hara. The dried roots of P. leptostachya var. asiatica Hara were extracted with 70% ethanol to generate the powdered extract, named PLE. Anti-angiogenic activity was detected using chick chorioallantoic membrane (CAM) assay. In vitro anti-inflammatory activity was evaluated via analyzing nitric oxide (NO) content, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Antioxidant activity was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and reactive oxygen species (ROS) level in the stimulated macrophage cells. Matrix metalloproteinase-9 (MMP-9) and -2 (MMP-2) activities in the culture media were detected using zymography. PLE exhibits an anti-angiogenic activity in the CAM assay, and displays an inhibitory action on the generation of NO in the LPS-stimulated macrophage cells. In the stimulated macrophage cells, it is able to diminish the enhanced ROS level. It can potently scavenge the stable DPPH free radical. It suppresses the induction of iNOS and COX-2 and the enhanced MMP-9 activity in the stimulated macrophage cells. Both monooxygenase and oxidase activities of tyrosinase were strongly inhibited by PLE. Taken together, the dried roots of P. leptostachya var. asiatica Hara possess anti-angiogenic, anti-inflammatory, antioxidant and skin whitening activities, which might partly provide its therapeutic efficacy in traditional medicine.

• Archives of Pharmacal Research
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• v.20 no.3
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• pp.225-233
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• 1997

A murine leukemia x LM fibroblast hybrid cell line with immune augmenting properties stimulated resistance to Mycobacterium avium complex (MAC) in mouse peritoneal macrophages, and in immune deficient beige mice (C57BL/6/bgj/bgj). The proliferation of MAC in mouse peritoneal macrophages was inhibited by medium conditioned by the growth of the hybrid cells (hybrid cell-CM). Under similar circumstances, media conditioned by the growth of LM cells (LM cell-CM), a mouse fibroblast cell line used as one parent in forming the hybrid cell, was exhibited no inhibitory effect. Treatment of mouse peritoneal macrophages with hybrid cell-CM, but not with LM cell-CM, stimulated the expression of each of four previously described macrophage activation antigens, suggesting that the hybrid cells formed immunomodulators in addition to those formed by LM cells. Furthermore, the morphology of the macrophages following treatment with hybrid cell-CM was clearly distinguishable from that following exposure of the cells to LM cell-CM. The therapeutic effects of hybrid cells on the progression of MAC-infection were indicated by the prolonged survival of MAC-infected immune-deficient beige mice. One hundred percent of treated animals survived more than 60 days, while untreated animals died in approximately 22 days.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.3
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• pp.257-265
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• 2023

Kidney ischemia/reperfusion (I/R) injury, a common cause of acute kidney injury (AKI), is associated with the migration of inflammatory cells into the kidney. Ras-related C3 botulinum toxin substrate 1 (Rac1), a member of the Rho family of small GTPase, plays an important role in inflammatory cell migration by cytoskeleton rearrangement. Here, we investigated the role of Rac1 on kidney I/R injury and macrophage migration. Male mice were subjected to either 25 min of bilateral ischemia followed by reperfusion (I/R) or a sham operation. Some mice were administrated with either NSC23766, an inhibitor of Rac1, or 0.9% NaCl (vehicle). Kidney damage and Rac1 activity and expression were measured. The migration and lamellipodia formation of RAW264.7 cells, mouse monocyte/macrophage, induced by monocyte chemoattractant protein-1 (MCP-1, a chemokine) were determined using transwell migration assay and phalloidin staining, respectively. In sham-operated kidneys, Rac1 was expressed in tubular cells and interstitial cells. In I/R-injured kidneys, Rac1 expression was decreased in tubule cells in correlation with the damage of tubular cells, whereas Rac1 expression increased in the interstitium in correlation with an increased population of F4/80 cells, monocytes/macrophages. I/R increased Rac1 activity without changing total Rac1 expression in the whole kidney lysates. NSC23766 administration blocked Rac1 activation and protected the kidney against I/R-induced kidney damage and interstitial F4/80 cell increase. NSC23766 suppressed monocyte MCP-1-induced lamellipodia and filopodia formation and migration of RAW 264.7 cells. These results indicate Rac1 inhibition protects the kidney against I/R via inhibition of monocytes/macrophages migration into the kidney.