• Journal of Neurogastroenterology and Motility
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• v.24 no.4
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• pp.628-642
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• 2018

Background/Aims A Subset of patients with irritable bowel syndrome (IBS) may have mild inflammation due to immune activation. Toll-like receptors (TLRs) and cytokines may cause intestinal inflammation. We studied their expression in relation to gut microbiota. Methods Expression of TLRs and cytokines was assessed in 47 IBS patients (Rome III) and 25 controls using quantitative real-time polymerase chain reaction. Immunohistochemistry was further performed to confirm the expression of TLR-4 and TLR-5. Results Of 47 patients with IBS, 20 had constipation (IBS-C), 20 diarrhea (IBS-D), and 7 unclassified (IBS-U). The mRNA levels of TLR-4 and TLR-5 were up-regulated in IBS patients than controls (P = 0.013 and P < 0.001, respectively). Expression of TLR-4 and TLR-5 at protein level was 4.2-folds and 6.6-folds higher in IBS-D than controls. The mRNA levels of IL-6 (P = 0.003), C-X-C motif chemokine ligand 11 (CXCL-11) (P < 0.001) and C-X-C motif chemokine receptor 3 (CXCR-3) (P < 0.001) were higher among IBS patients than controls. Expression of IL-6 (P = 0.002), CXCL-11 (P < 0.001), and CXCR-3 (P < 0.001) were up-regulated and IL-10 (P = 0.012) was down-regulated in IBS-D patients than controls. Positive correlation was seen between TLR-4 and IL-6 (P = 0.043), CXCR-3, and CXCL-11 (P = 0.047), and IL-6 and CXCR-3 (P = 0.003). Stool frequency per week showed positive correlation with mRNA levels of TLR-4 (P = 0.016) and CXCR-3 (P = 0.005), but inversely correlated with IL-10 (P = 0.002). Copy number of Lactobacillus (P = 0.045) and Bifidobacterium (P = 0.011) showed correlation with IL-10 in IBS-C, while Gram-positive (P = 0.031) and Gram-negative bacteria (P = 0.010) showed correlation with CXCL-11 in IBS-D patients. Conclusions Altered immune activation in response to dysbiotic microbiota may promote intestinal inflammation in a subset of patients with IBS.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.634-639
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• 1998

Seven transmembrane segment (7TMS) receptors for chemokines and related molecules have been demonstrated to be essential, in addition to CD4, for HIV and SIV infection. The beta-chemokine receptor CCR5 is the primary, perhaps sole, coreceptor for HIV-1 during the early and chronic phases of infection, and supports infection by most primary HIV-1 and many SIV isolates. Late-stage primary and laboratory-adapted HIV-1, HIV-2, and SIV isolates can use other 7TMS receptors. CXCR4 appears especially important in late-stage HIV infection; several related receptors can also be used. The specificity of SIV viruses is similar. Commonalities among these receptors, combined with analyses of mutated molecules, indicate that discrete, conformationally-depenclent sites on the chemokine receptors determine their association with the third variable and conserved regions of viral envelope glycoproteins. These studies are useful for elucidating the mechanism and molecular determinants of HIV-1 entry, and of inhibitors to that entry.

• Hanyang Medical Reviews
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• v.33 no.1
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• pp.10-16
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• 2013

Follicular helper T cells (Tfh) play a significant role in providing T cell help to B cells during the germinal center reaction, where somatic hypermutation, affinity maturation, isotype class switching, and the differentiation of memory B cells and long-lived plasma cells occur. Antigen-specific T cells with IL-6 and IL-21 upregulate CXCR5, which is required for the migration of T cells into B cell follicles, where these T cells mature into Tfh. The surface markers including PD-1, ICOS, and CD40L play a significant role in providing T cell help to B cells. The upregulation of transcription factor Bcl-6 induces the expression of CXCR5, which is an important factor for Tfh differentiation, by inhibiting the expression of other lineage-specific transcription factors such as T-bet, GATA3, and RORγt. Surprisingly, recent evidence suggests that CD4 T cells already committed to Th1, Th2, and Th17 cells obtain flexibility in their differentiation programs by downregulating T-bet, GATA3, and RORγt, upregulating Bcl-6 and thus convert into Tfh. Limiting the numbers of Tfh within germinal centers is important in the regulation of the autoantibody production that is central to autoimmune diseases. Recently, it was revealed that the germinal center reaction and the size of the Tfh population are also regulated by thymus-derived follicular regulatory T cells (Tfr) expressing CXCR5 and Foxp3. Dysregulation of Tfh appears to be a pathogenic cause of autoimmune disease suggesting that tight regulation of Tfh and germinal center reaction by Tfr is essential for maintaining immune tolerance. Therefore, the balance between Tfh and Tfr appears to be a critical peripheral tolerance mechanism that can inhibit autoimmune disorders.

• Parasites, Hosts and Diseases
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• v.57 no.2
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• pp.201-206
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• 2019

The roles of mast cells in allergic diseases and helminth infections are well known. However, the roles of mast cells in T. gondii infection is poorly understood. This study was focused on the production of pro-inflammatory cytokines ($TNF-{\alpha}$, IL-4), chemokines (CXCL8, MCP-1) and nitric oxide (NO) by mast cells in response to soluble lysate of T. gondii tachyzoites. Production of CXCL8 (IL-8), MCP-1, $TNF-{\alpha}$ and IL-4 were measured by RT-PCR and ELISA. Western blot were used for detection of CXCR-1 and CXCR2. Our results showed that T. gondii lysates triggered mast cells to release CXCL8, MCP-1, $TNF-{\alpha}$, IL-4 and to produce NO. This suggests that mast cells play an important role in inflammatory responses to T. gondii.

• International Journal of Oral Biology
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• v.47 no.4
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• pp.55-62
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• 2022

Bioactive flavonoids have been shown to improve the biological activity of stem cells derived from different sources in tissue regeneration. The goal of this study was to see how naringin, a natural flavonoid discovered in citrus fruits, affected the biological properties of human dental pulp stem cells (HDPSCs). In this study, we found that naringin increases the migratory ability of HDPSCs. Naringin increased matrix metalloproteinase-2 (MMP-2) and C-X-C chemokine receptor type 4 (CXCR4) mRNA and protein expression in HDPSCs. ARP100, a selective MMP-2 inhibitor, and AMD3100, a CXCR4 antagonist, both inhibited the naringin-induced migration of HDPSCs. Furthermore, naringin increased osteogenic differentiation of HDPSCs and the expression of the osteogenic-related marker, alkaline phosphatase in HDPSCs. Taken together, our findings suggest that naringin may be beneficial on dental tissue or bone regeneration by increasing the biological activities of HDPSCs.

• Molecules and Cells
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• v.40 no.6
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• pp.386-392
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• 2017

Periodontal ligament stem cells (PDLSCs) are multipotent stem cells derived from periodontium and have mesenchymal stem cell (MSC)-like characteristics. Recently, the perivascular region was recognized as the developmental origin of MSCs, which suggests the in vivo angiogenic potential of PDLSCs. In this study, we investigated whether PDLSCs could be a potential source of perivascular cells, which could contribute to in vivo angiogenesis. PDLSCs exhibited typical MSC-like characteristics such as the expression pattern of surface markers (CD29, CD44, CD73, and CD105) and differentiation potentials (osteogenic and adipogenic differentiation). Moreover, PDLSCs expressed perivascular cell markers such as NG2, ${\alpha}-smooth$ muscle actin, platelet-derived growth factor receptor ${\beta}$, and CD146. We conducted an in vivo Matrigel plug assay to confirm the in vivo angiogenic potential of PDLSCs. We could not observe significant vessel-like structures with PDLSCs alone or human umbilical vein endothelial cells (HUVECs) alone at day 7 after injection. However, when PDLSCs and HUVECs were co-injected, there were vessel-like structures containing red blood cells in the lumens, which suggested that anastomosis occurred between newly formed vessels and host circulatory system. To block the $SDF-1{\alpha}$ and CXCR4 axis between PDLSCs and HUVECs, AMD3100, a CXCR4 antagonist, was added into the Matrigel plug. After day 3 and day 7 after injection, there were no significant vessel-like structures. In conclusion, we demonstrated the perivascular characteristics of PDLSCs and their contribution to in vivo angiogenesis, which might imply potential application of PDLSCs into the neovascularization of tissue engineering and vascular diseases.

• Animal Bioscience
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• v.34 no.10
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• pp.1590-1599
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• 2021

Objective: This study investigates the expression patterns of toll-like receptors (TLRs) and intracellular mediators in horse muscle cells after exercise, and the relationship between TLRS expression in stressed horse muscle cells and immune cell migration toward them. Methods: The expression patterns of the TLRs (TLR2, TLR4, and TLR8) and downstream signaling pathway-related genes (myeloid differentiation primary response 88 [MYD88]; activating transcription factor 3 [ATF3]) are examined in horse tissues, and horse peripheral blood mononuclear cells (PBMCs), polymorphonuclear cells (PMNs) and muscles in response to exercise, using the quantitative reverse transcription-polymerase chain reaction (qPCR). Expressions of chemokine receptor genes, i.e., C-X-C motif chemokine receptor 2 (CXCR2) and C-C motif chemokine receptor 5 (CCR5), are studied in PBMCs and PMNs. A horse muscle cell line is developed by transfecting SV-T antigen into fetal muscle cells, followed by examination of muscle-specific genes. Horse muscle cells are treated with stressors, i.e., cortisol, hydrogen peroxide (H₂O₂), and heat, to mimic stress conditions in vitro, and the expression of TLR4 and TLR8 are examined in stressed muscle cells, in addition to migration activity of PBMCs toward stressed muscle cells. Results: The qPCR revealed that TLR4 message was expressed in cerebrum, cerebellum, thymus, lung, liver, kidney, and muscle, whereas TLR8 expressed in thymus, lung, and kidney, while TLR2 expressed in thymus, lung, and kidney. Expressions of TLRs, i.e., TLR4 and TLR8, and mediators, i.e., MYD88 and ATF3, were upregulated in muscle, PBMCs and PMNs in response to exercise. Expressions of CXCR2 and CCR5 were also upregulated in PBMCs and PMNs after exercise. In the muscle cell line, TLR4 and TLR8 expressions were upregulated when cells were treated with stressors such as cortisol, H₂O₂, and heat. Migration of PBMCs toward stressed muscle cells was increased by exercise and oxidative stresses, and combinations of these. Treatment with methylsulfonylmethane (MSM), an antioxidant on stressed muscle cells, reduced migration of PBMCs toward stressed muscle cells. Conclusion: In this study, we have successfully cultured horse skeletal muscle cells, isolated horse PBMCs, and established an in vitro system for studying stress-related gene expressions and function. Expression of TLR4, TLR8, CXCR2, and CCR5 in horse muscle cells was higher in response to stressors such as cortisol, H₂O₂, and heat, or combinations of these. In addition, migration of PBMCs toward muscle cells was increased when muscle cells were under stress, but inhibition of reactive oxygen species by MSM modulated migratory activity of PBMCs to stressed muscle cells. Further study is necessary to investigate the biological function(s) of the TLR gene family in horse muscle cells.

• Molecules and Cells
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• v.43 no.9
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• pp.793-803
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• 2020

Myeloid-derived suppressor cells (MDSCs) promote tumour progression by contributing to angiogenesis, immunosuppression, and immunotherapy resistance. Although recent studies have shown that microRNAs (miRNAs) can promote the expansion of MDSCs in the tumour environment, the mechanisms involved in this process are largely unknown. Here, we report that microRNA 449c (miR-449c) expression was upregulated in myeloid progenitor cells upon activation of C-X-C motif chemokine receptor 2 (CXCR2) under tumour conditions. MiR-449c upregulation increased the generation of monocytic MDSCs (mo-MDSCs). The increased expression of miR-449c could target STAT6 mRNA in myeloid progenitor cells to shift the differentiation balance of myeloid progenitor cells and lead to an enhancement of the mo-MDSCs population in the tumour environment. Thus, our results demonstrate that the miR-449c/STAT6 axis is involved in the expansion of mo-MDSCs from myeloid progenitor cells upon activation of CXCR2, and thus, inhibition of miR-449c/STAT6 signalling may help to attenuate tumour progression.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.113-113
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• 2019

Diallyl trisulfide (DATS) is an organic polysulfide compound found in garlic. Although certain studies have demonstrated that DATS possesses strong anti-inflammatory activity, the underlying molecular mechanisms remain largely unresolved. In this study, we examined whether DATS exerts anti-inflammatory activity and investigated the possible mechanisms. Our results indicated that DATS significantly suppressed the lipopolysaccharide (LPS)-induced release of nitric oxide (NO) and prostaglandin E2 by inhibiting inducible NO synthase and cyclooxygenase-2 expression at the transcriptional and post-transcriptional levels in RAW 264.7 macrophages. DATS also down-regulated Toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 expression, and inhibited nuclear translocation of nuclear transcription factor-kappa B (NF-${\kappa}B$) in LPS-stimulated 264.7 macrophages. Furthermore, we found that these inhibitory effects of DATS were associated with the inhibition of chemokine receptor (CXCR4) and ligand (CXCL12) expression, and reactive oxygen species generation. Overall, the present data indicated that DATS had anti-inflammatory effects on LPS-activated macrophages, possibly via inhibiting the TLR4/NF-kB and/or chemokine signaling pathways, and DATS could be a potential drug therapy for inflammation and its associated diseases.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.182-187
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• 2015

Zerumbone is a major component of the essential oils of Zingiber zerumbet Smith and is known to have a number of effects on the functions of various cells, including immune cells. Many reports present the zerumbone's functions in various biological environments including cancer and inflammation. In this report, using a transwell system, we confirmed that zerumbone decreased the stromal cell-driven factor-$1{\alpha}$ (SDF-$1{\alpha}$), induced migration of Jurkat cells; about a 25% decrease in the case of 100 ng/mL SDF-$1{\alpha}$ treatment, 17% decrease in the case of 200 ng/mL. Whereas, no significant changes of basic cellular proliferation were observed after zerumbone treatment. These results are novel and promising functions of zerumbone on T cell physiology. At the same time, there is a great need to confirm the results using more physiological T cells and to proceed with cellular and biochemical mechanism studies, measuring apoptosis, CXCR4 expression and phosphorylation of ZAP-70 and Erk1/2.