• Journal of Oral Medicine and Pain
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• v.33 no.2
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• pp.105-110
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• 2008

Baicalin is a flavonoid compound isolated from the medicinal plant Scutellaria baicalensis. It is known to affect multiple biological functions, including of antibacterial, anti-viral, anti-inflammatory and analgesic effects. Baicalin can inhibit nuclear factor-kappaB activation. It has been reported that some flavonoids possess the effects of bone metabolism. The present study was undertaken to determine the possible cellular mechanism of action of baicalin in osteoblasts. The effects on the osteoblast were determined by measuring cell proliferation, cell viability, alkaline phosphatase activity, and osteoprotegerin secretion. Baicalin has no effect on the osteoblastic cell proliferation and cell viability. Baicalin treatment showed increase in alkaline phosphatase activity and osteoprotegerin secretion of osteoblasts. Thus, baicalin may be a regulatory protein within the bone.

• BMB Reports
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• v.54 no.12
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• pp.614-619
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• 2021

Hepatitis B virus (HBV) infection is a major cause of hepatocellular carcinoma (HCC), which is a highly aggressive cancer. HBV X protein (HBx), one of four HBV gene products, plays pivotal roles in the development and metastasis of HCC. It has been reported that HBx induces liver cancer cell migration and reorganizes actin cytoskeleton, however the molecular basis for actin cytoskeleton reorganization remains obscure. In this study, we for the first time report that HBx promotes actin polymerization and liver cancer cell migration by regulating calcium modulated protein, calmodulin (CaM). HBx physically interacts with CaM to control the level of phosphorylated cofilin, an actin depolymerizing factor. Mechanistically, HBx interacts with CaM, liberates Hsp90 from its inhibitory partner CaM, and increases the activity of Hsp90, thus activating LIMK1/cofilin pathway. Interestingly, the interaction between HBx and CaM is calcium-dependent and requires the CaM binding motif on HBx. These results indicate that HBx modulates CaM which plays a regulatory role in Hsp90/LIMK1/cofilin pathway of actin reorganization, suggesting a new mechanism of HBV-induced HCC metastasis specifically derived by HBx.

• BMB Reports
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• v.53 no.4
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• pp.206-211
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• 2020

Vascular smooth muscle cells (VSMCs) are a unique cell type that has unusual plasticity controlled by environmental stimuli. As an abnormal increase of VSMC proliferation is associated with various vascular diseases, tight regulation of VSMC phenotypes is essential for maintaining vascular homeostasis. Hypoxia is one environmental stress that stimulates VSMC proliferation. Emerging evidence has indicated that microRNAs (miRNAs) are critical regulators in the hypoxic responses of VSMCs. Therefore, we previously investigated miRNAs modulated by hypoxia in VSMCs and found that miR-1260b is one of the most upregulated miRNAs under hypoxia. However, the mechanism that underlies the regulation of VSMCs via miR-1260b in response to hypoxia has not been explored. Here we demonstrated that hypoxia-induced miR-1260b promotes VSMC proliferation. We also identified growth differentiation factor 11 (GDF11), a member of the TGF-β superfamily, as a novel target of miR-1260b. miR-1260b directly targets the 3'UTR of GDF11. Downregulation of GDF11 inhibited Smad signaling and consequently enhanced the proliferation of VSMCs. Our findings suggest that miR-1260b-mediated GDF11-Smad-dependent signaling is an essential regulatory mechanism in the proliferation of VSMCs, and this axis is modulated by hypoxia to promote abnormal VSMC proliferation. Therefore, our study unveils a novel function of miR-1260b in the pathological proliferation of VSMCs under hypoxia.

• Molecules and Cells
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• v.28 no.4
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• pp.365-368
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• 2009

Toll-like receptors (TLRs) play an important role in host defense by sensing invading microbial pathogens and initiating innate immune responses. The stimulation of TLRs by microbial components triggers the activation of myeloid differential factor 88 (MyD88)- and toll-interleukin-1 receptor domain-containing adapter inducing interferon-${\beta}$ (TRIF)-dependent downstream signaling pathways. Isoliquiritigenin (ILG), an active ingredient of Licorice, has been used for centuries to treat many chronic diseases. ILG inhibits the MyD88-dependent pathway by inhibiting the activity of inhibitor-${\kappa}B$ kinase. However, it is not known whether ILG inhibits the TRIF-dependent pathway. To evaluate the therapeutic potential of ILG, we examined its effect on signal transduction via the TRIF-dependent pathway of TLRs induced by several agonists. ILG inhibited nuclear factor-${\kappa}B$ and interferon regulatory factor 3 activation induced by lipopolysaccharide or polyinosinic-polycytidylic acid. ILG inhibited the lipopolysaccharide-induced phosphorylation of interferon regulatory factor 3 as well as interferon-inducible genes such as interferon inducible protein-10, and regulated activation of normal T-cell expressed and secreted (RANTES). These results suggest that ILG can modulate TRIF-dependent signaling pathways of TLRs, leading to decreased inflammatory gene expression.

• Journal of Acupuncture Research
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• v.33 no.1
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• pp.47-56
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• 2016

Objectives : This study examined the effects of Bee venom on apoptosis in NCI-H157 human lung cancer cells and for promoting the apoptosis effects of Natural killer cell. Methods : Bee venom and Natural killer-92 cells were cultured either separately from or together with NCI-H157 cells for 24 hours. To figure out whether Bee venom enhances the cytotoxic effect of Natural Killer-92 cells, a cell viability assay was conducted. To observe the changes in Death receptors, apoptotic regulatory proteins and Nuclear $Factor-{\kappa}B$, western blot analysis was conducted. To observe the effect of Bee venom through an extrinsic mechanism, a transfection assay was conducted. Results : 1. Natural killer-92 cells and Bee venom significantly inhibited the growth of NCI-H157 cells and co-culture had more inhibitory effect than the separate culture. 2. Expressions of Fas, DR3, DR6, Bax, caspase-3, caspase-8, cleaved caspase-3, cleaved caspase-8 were increased, and expressions of Bcl-2 and cIAP were decreased. More efficacy was observed in co-culture than in separate culture. 3. Nuclear $Factor-{\kappa}B$ activation was clearly decreased. And co-culture showed much less activation than separate culture. 4. As a result of treatment for DR-siRNA, the reduced cell viability of NCI-H157 cells and the activity of Nuclear $Factor-{\kappa}B$ were increased. With this, it can be seen that Bee venom and Natural killer-92 cells have an effect on the cancer cells through the extrinsic mechanism. Conclusion : Bee venom is effective in inhibiting the growth of human lung cancer cells. Furthermore Bee venom effectively enhances the functions of Natural killer cells.

• Clinical and Experimental Pediatrics
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• v.59 no.5
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• pp.205-211
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• 2016

Idiopathic nephrotic syndrome (INS) in children is characterized by massive proteinuria and hypoalbuminemia. Minimal change nephrotic syndrome (MCNS) is the most common form of INS in children. The pathogenesis of MCNS still remains unclear, however, several hypotheses have been recently proposed. For several decades, MCNS has been considered a T-cell disorder, which causes the impairment of the glomerular filtration barrier with the release of different circulating factors. Increased levels of several cytokines are also suggested. Recently, a "two-hit" theory was proposed that included the induction of CD80 (B7-1) and regulatory T-cell (Treg) dysfunction, with or without impaired autoregulatory functions of the podocyte. In contrast to the well-established involvement of T cells, the role of B cells has not been clearly identified. However, B-cell biology has recently gained more attention, because rituximab (a monoclonal antibody directed against CD20-bearing cells) demonstrated a very good therapeutic response in the treatment of childhood and adult MCNS. Here, we discuss recent insights into the pathogenesis of MCNS in children.

• Molecules and Cells
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• v.27 no.2
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• pp.211-215
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• 2009

Toll-like receptors (TLRs) play a critical role in sensing microbial components and inducing innate immune and inflammatory responses by recognizing invading microbial pathogens. Lipopolysaccharide-induced dimerization of TLR4 is required for the activation of downstream signaling pathways including nuclear factor-kappa B ($NF-{\kappa}B$). Therefore, TLR4 dimerization may be an early regulatory event in activating ligand-induced signaling pathways and induction of subsequent immune responses. Here, we report biochemical evidence that 6-shogaol, the most bioactive component of ginger, inhibits lipopolysaccharide-induced dimerization of TLR4 resulting in the inhibition of $NF-{\kappa}B$ activation and the expression of cyclooxygenase-2. Furthermore, we demonstrate that 6-shogaol can directly inhibit TLR-mediated signaling pathways at the receptor level. These results suggest that 6-shogaol can modulate TLR-mediated inflammatory responses, which may influence the risk of chronic inflammatory diseases.

• The Korean Journal of Food And Nutrition
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• v.23 no.1
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• pp.118-123
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• 2010

To estimate the regulatory effects of Scutellaria baicalensis extracts on melanin biosynthesis, we evaluated the regulatory effects of the tyrosinase gene on B16 melanoma cells. The results revealed that methanolic extracts of Scutellaria baicalensis resulted in a high increase in the expression of the tyrosinase gene. Specifically, treatment with extracts at concentrations of $10\;{\mu}g/m{\ell}$ and $100\;{\mu}g/m{\ell}$ resulted in increases in tyrosinase gene expression rates of approximately 231% and 256%, respectively, when compared to the control. Moreover, the solvent fraction layers(methylene chloride, ethyl acetate, butyl alcohol, water) improved the expression of the tyrosinase gene, but to a lesser degree than the methanolic extracts. An MTT assay revealed, that the methanolic extract exhibited very low cytotoxicities at $10\;{\mu}g/m{\ell}$ and $100\;{\mu}g/m{\ell}$. Taken together, the results of this study indicated that the methanolic extracts of Scutellaria baicalensis was a very effective positive regulator of tyrosinase gene expression.

• Molecules and Cells
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• v.39 no.1
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• pp.72-76
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• 2016

Cell death pathways such as apoptosis can be activated in response to oxidative stress, enabling the disposal of damaged cells. In contrast, controlled intracellular redox events are proposed to be a significant event during apoptosis signaling, regardless of the initiating stimulus. In this scenario oxidants act as second messengers, mediating the post-translational modification of specific regulatory proteins. The exact mechanism of this signaling is unclear, but increased understanding offers the potential to promote or inhibit apoptosis through modulating the redox environment of cells. Peroxiredoxins are thiol peroxidases that remove hydroperoxides, and are also emerging as important players in cellular redox signaling. This review discusses the potential role of peroxiredoxins in the regulation of apoptosis, and also their ability to act as biomarkers of redox changes during the initiation and progression of cell death.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.4981-4985
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• 2015

Background: Colorectal cancer (CRC) is a leading cause of morbidity and mortality worldwide. Targeting autophagic cell death is emerging as a novel strategy in cancer chemotherapy. Aldose reductase (AR) catalyzes the rate limiting step of the polyol pathway of glucose metabolism; besides reducing glucose to sorbitol, AR reduces lipid peroxidation-derived aldehydes and their glutathione conjugates. A complex interplay between autophagic cell death and/or survival may in turn govern tumor metastasis. This exploratory study aimed to investigate the potential role of AR inhibition using a novel inhibitor Fidarestat in the regulation of autophagy in CRC cells. Materials and Methods: For glucose depletion (GD), HT-29 and SW480 CRC cells were rinsed with glucose-free RPMI-1640, followed by incubation in GD medium +/- Fidarestat ($10{\mu}M$). Proteins were extracted by a RIPA-method followed by Western blotting ($35-50{\mu}g$ of protein; n=3). Results: Autophagic regulatory markers, primarily, microtubule associated protein light chain (LC) 3, autophagy-related gene (ATG) 5, ATG 7 and Beclin-1 were expressed in CRC cells; glyceraldehyde-3 phosphate dehydrogenase (GAPDH) was used as an internal reference. LC3 II (14 kDa) expression was relatively high compared to LC3A/B I levels in both CRC cell lines, suggesting occurrence of autophagy. Expression of non-autophagic markers, high mobility group box (HMG)-1 and Bcl-2, was comparatively low. Conclusions: GD +/- ARI induced autophagy in HT-29 and SW-480 cells, thereby implicating Fidarestat as a promising therapeutic agent for colorectal cancer; future studies with more potent ARIs are warranted to fully dissect the molecular regulatory networks for autophagy in colorectal carcinoma.