Yun-Hee Rhee

Melatonin attenuated adipogenesis through reduction of the CCAAT/enhancer binding protein beta by regulating the glycogen synthase 3 beta in human mesenchymal stem cells

Adipogenic differentiation is characterized by an increase in two major transcription factors: peroxisome proliferator-activated receptor gamma (PPARγ) and the CCAAT/enhancer binding protein alpha (C/EBPα). These two signals are influenced by C/EBPβ and C/EBPδ and cross-regulate each other’s expression during the initial stages of adipogenesis. Melatonin has been known to act as not only a direct scavenger of free radicals but also an inhibitor of glycogen synthase kinase 3β (GSK-3β). Here, we report that melatonin inhibits the adipogenic differentiation of human mesenchymal stem cells (hMSCs) which is due to the regulations of C/EBPβ in the early stage of adipogenic differentiation. Melatonin reduced the lipid accumulation, adiponectin, and lipoprotein lipase (LPL) during the adipogenic differentiation of hMSCs. Since C/EBPβ has been associated with the activation of PPARγ and the consensus site of ERK/GSK-3β, PPARγ and β-catenin were detected by immunofluorescence staining after pretreatment of melatonin. Melatonin blocked the activation of PPARγ which induced the degradation of β-catenin. Melatonin also decreased the levels of cyclic adenosine-3,5-monophosphate (cAMP) and reactive oxygen species (ROS). The cAMP triggered the activity of C/EBPβ which is a critical inducer of PPARγ and C/EBPα activation in the early stage of adipogenic differentiation, and this is further affected by ROS production. The adipogenic marker proteins such as PPARγ, C/EBPα, C/EBPβ, and pERK were also decreased by melatonin. In summary, melatonin inhibited the cAMP synthesis through ROS reduction and the phosphorylation of the ERK/GSK-3β site which is known to be responsible for C/EBPβ activation for adipogenic differentiation in hMSCs.

Circumferential irradiation for interstitial coagulation of urethral stricture

An optical diffuser was developed to achieve radially uniform light irradiation by micro-machining helical patterns on the fiber surface for endoscopically treating urethral stricture. Spatial emission from the diffuser was evaluated by goniometric measurements. A computational model was developed to predict spatio-temporal heat distribution during the interstitial coagulation. The fabricated diffuser yielded circumferential light distribution with slightly concentrated energy at the proximal end. Both simulation and tissue testing demonstrated approximately 1-mm coagulation thickness at 6 W for 10 sec with 1470 nm. The proposed optical diffuser may be a feasible tool to treat the urethral stricture in a uniform manner.

The role of TRPV1 in the CD4 + T cell-mediated inflammatory response of allergic rhinitis

Transient receptor potential vanilloid 1 (TRPV1), which has been identified as a molecular target for the activation of sensory neurons by various painful stimuli, was reported to regulate the signaling and activation of CD4+ T cells. However, the role of TRPV1 in CD4+ T cell in allergic rhinitis remains poorly understood. In this study, TRPV1 expression was localized in CD4+ T cells. Both knockout and chemical inhibition of TRPV1 suppressed Th2/Th17 cytokine production in CD4 T cells and Jurkat T cells, respectively, and can suppress T cell receptor signaling pathways including NF-κB, MAP kinase, and NFAT. In TRPV1 knockout allergic rhinitis (AR) mice, eosinophil infiltration, Th2/Th17 cytokines in the nasal mucosa, and total and ova-specific IgE levels in serum decreased, compared with wild-type AR mice. The TRPV1 antagonists, BCTC or theobromine, showed similar inhibitory immunologic effects on AR mice models. In addition, the number of TRPV1+/CD4+ inflammatory cells increased in the nasal mucosa of patients with AR, compared with that of control subjects. Thus, TRPV1 activation on CD4+ T cells is involved in T cell receptor signaling, and it could be a novel therapeutic target in AR.

CXCR4 and PTEN are involved in the anti-metastatic regulation of anethole in DU145 prostate cancer cells.

Anethole has been known to have chemopreventive activities as a suppressor of the incidence and multiplicity of both invasive and noninvasive carcinomas. The goal of this study was to understand the anti-metastatic effect of anethole through C-X-C chemokine receptor type 4 (CXCR4)/tumor suppressor phosphatase and tensin homologue (PTEN) axis in DU145 prostate cancer cells. Anethole reduced both of the RNA level and the protein level of CXCR4 in a dose-dependent manner without cytotoxicity. Anethole also reduced the expression of CXCR4 and prolonged the expression of PTEN in DU145 prostate cancers. The phosphorylation of AKT and phosphatidylinositol-3kinase (PI3K) were decreased with anethole. The inhibition metastatic effect of anethole was arisen from down-regulating CXCR4 and up-regulating PTEN. Morphologically, anethole significantly inhibited the invasion of DU145 cell and down-regulated the activities of matrix-metalloproteinase (MMPs) in a dose-dependent manner. However, anethole didnot decrease the phosphorylation of PI3K and AKT while PTEN was silenced. Furthermore, the CXCR4 inhibition of anethole was not caused to proteasomal or lysosomal of CXCR4. Taken together, anethole demonstrated to act as the CXCR4 antagonist and as the PTEN activator which resulted to PI3K/AKT-mediated inhibition of the metastatic prostate cancer progressions.

Enhanced survival of ischemic skin flap by combined treatment with bone marrow-derived stem cells and low-level light irradiation

The aim of this study is to examine the enhanced survival effect of ischemic skin flap by combined treatment with bone marrow-derived stem cells (BMSCs) and low-level light irradiation (LLLI). The neovasculogenic effect of BMSCs induced by LLLI was detected using a wound healing and tube formation assay. ICR mice were divided into four groups: control group, LLLI group, BMSCs group, and combine-treated group. The percentage of skin flap necrosis area was calculated on the seventh post-operative day. Specimens were harvested for histologic analyses. LLLI promoted BMSC migration and tube formation. The flap survival rate of combined treated group was significantly higher than that of the control group. Histologic results demonstrated a significant increase in neovascularization in the combined treatment group. This study demonstrates that combination treatment of BMSCs and LLLI could enhance the survival of ischemic skin flap in a mouse model.

Sulforaphene–Carboplatin Combination Synergistically Enhances Apoptosis by Disruption of Mitochondrial Membrane Potential and Cell Cycle Arrest in Human Non-Small Cell Lung Carcinoma

Worldwide non-small cell lung cancer (NSCLC) causes substantial morbidity and mortality among human populations. Due to the severe side effects and low survival rate of patients with the conventional drugs, implementation of new combination therapies is much needed. The aim of this study was to evaluate the efficacy of a combination therapy with a conventional drug and a natural medicine. We compared the combination of chemotherapy drug carboplatin and the radish-derived isothiocyanate compound sulforaphene, which synergistically induces higher apoptosis and growth inhibition in A549, to the drug alone in human NSCLC cells. We found that this combination group significantly induced higher depolarization of mitochondrial membrane potential (MMP) and intracellular reactive oxygen species generation than the single drug dose, followed by cell cycle arrest at the G0/G1 phase after 24 h of incubation. In addition to that, the Western blot assays showed that combination treatment inhibited the expression of Bcl-2 and successively upregulated the expression of Bax, cytochrome C, apoptosis-inducing factor, caspase-9 and -3, and cleaved poly ADP ribose polymerase. It also modulated the expression of PI3K, p-extracellular signal-regulated kinase (1/2), and p-c-Jun N-terminal kinase indicating the involvement of antiproliferative properties. Further pretreatment with pan-caspase inhibitor Z-VAD-fmk was carried out to confirm the effect of caspases in the combination therapy-induced apoptosis. To summarize, this is the first report that sulforaphene-carboplatin combination treatment synergistically promotes enhanced apoptosis and antiproliferative effect over single drug treatment against A549, human NSCLC cells through caspase activation, MMP disruption, and cell cycle arrest. This study demonstrates that the duel character of this combination therapy may be an effective replacement for conventional therapy alone against NSCLC.

Sulforaphene Enhances The Efficacy of Photodynamic Therapy In Anaplastic Thyroid Cancer Through Ras/RAF/MEK/ERK Pathway Suppression

Sulforaphene (SFE), a natural isothiocyanate from cruciferous vegetables has shown a potential anticancer effect against cervical and lung cancer. Palliative treatments like photodynamic therapy (PDT) are being implemented for a long time however, the results are still not promising in case of aggressive cancers like anaplastic thyroid cancer. The objective of this work is to establish an alternative method with the combination of photofrin-PDT and sulforaphene, a natural isothiocyanate from cruciferous vegetables, against human anaplastic thyroid cancer to enhance the efficacy of PDT. In this study, cell viability of FRO cells due to combination treatment was analyzed by MTT assay, Cell cycle arrest, MMP depolarization and ROS generation, analyzed by flow cytometry. Western blot analysis of various proliferative proteins was performed to assess the activity of combination treatment against FRO cells. From the results, sulforaphene alone showed no cytotoxicity against normal cells, however, combination of sulforaphene and photofrin mediated PDT showed a noticeable decrease in cell proliferation against FRO cells. Combination treatment synergistically caused cell cycle arrest via ROS generation and MMP depolarization. The expressions of Ras, MEK, ERK, B-Raf proteins significantly modulated due to combination treatment. PDT and SFE can induce apoptosis in anaplastic thyroid cancer cells individually but while treated in combination, it enhanced the apoptotic and anti-proliferative effect, much higher than the individual doses. In summary, our work designates sulforaphene as a unique natural enhancer of efficacy with PDT against anaplastic thyroid cancer.

Ex vivo laser lipolysis assisted with radially diffusing optical applicator

Abstract. Laser-assisted lipolysis has been implemented to reduce body fat in light of thermal interactions with adipose tissue. However, using a flat fiber with high irradiance often needs rapid cannula movements and even undesirable thermal injury due to direct tissue contact. The aim of the current study was to explore the feasibility of a radially diffusing optical applicator to liquefy the adipose tissue for effective laser lipolysis. The proposed diffuser was evaluated with a flat fiber in terms of temperature elevation and tissue liquefaction after laser lipolysis with a 980-nm wavelength. Given the same power (20 W), the diffusing applicator generated a 30% slower temperature increase with a 25% lower maximum temperature (84±3.2°C in 1 min; p<0.001) in the tissue, compared with the flat fiber. Under the equivalent temperature development, the diffuser induced up to fivefold larger area of the adipose liquefaction due to radial light emission than the flat fiber. Ex vivo tissue tests for 5-min irradiation demonstrated that the diffuser (1.24±0.15  g) liquefied 66% more adipose tissue than the flat fiber (0.75±0.05  g). The proposed diffusing applicator can be a feasible therapeutic device for laser lipolysis due to low temperature development and wide coverage of thermal treatment.

Anti-oxidant and anti-inflammatory effects of rice bran and green tea fermentation mixture on lipopolysaccharideinduced RAW 264.7 macrophages

Purpose : To investigate the anti-inflammatory and anti-oxidant properties of an enzyme bath of Oryza sativa (rice bran) and Camellia sinensis O. Kuntz (green tea) fermented with Bacillus subtilis (OCB). Methods : The anti-oxidant effects of OCB were assessed by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay and flow cytometry. The anti-inflammatory effects of OCB were assessed by a nitric oxide (NO) assay. Enzyme-linked immunosorbent assay and real-time polymerase chain reaction were used to quantify expression of pro-inflammatory cytokines in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The major compounds of OCB were identified using high performance liquid chromatography (HPLC) analysis. Results : OCB had no cytotoxic effect on LPS-stimulated macrophages or peripheral blood mononuclear cells up to 1 mg/mL. OCB displayed anti-oxidant effects comparable to those of ascorbic acid and reduced reactive oxygen species (ROS) levels in target cells. OCB treatment of LPSstimulated mavrophages decreased nitric oxide (NO), NO synthase (iNOS), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2) and key pro-inflammatory cytokine expressions, suggesting that OCB acts as an anti-oxidant and anti-inflammatory agent by reducing ROS levels and inhibiting pro-inflammatory mediators. The main effector compounds in OCB were epicatechin gallate, cathechin, synigrin acid, epicathechin, epigallocatechin gallate, rutin, and isoquercetin, which are known anti-oxidants. Conclusion : OCB fermentation product may be used as synergistic adjuvant therapy for inflammatory diseases. Keywords : Rice bran, Green tea, Bacillus subtilis , Enzyme bath, Anti-oxidant, Anti-inflammation

Concentric photothermal coagulation with basket-integrated optical device for treatment of tracheal stenosis

A basket-integrated optical device is developed to consistently treat tubular tissue by centering an optical diffuser in the lumen. Four nitinol arms in conjunction with the optical diffusing applicator are deployed to induce homogeneous circumferential light emission and concentric photothermal coagulation on tracheal tissue. A 1470-nm laser light is employed for the tissue testing at various irradiation conditions and evaluated in terms of thermal gradient and temperature evolution. Preliminary experiments on liver tissue demonstrate the concentric development of the radial thermal coagulation in the tissue (eccentric ratio = ~5.5%). The interstitial tissue temperature increases with the total amount of energy delivery (around 65°C). Ex vivo trachea testing yields up to 16.5% tissue shrinkage due to dehydration as well as uniform ablation of the cilia and goblet cells in a mucosa layer under 7-W irradiation for 10 s. The proposed optical device may be a feasible therapeutic method to entail the circumferential coagulation in the tubular tissues in a reliable manner.