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83 result(s) for "Park, Kyung-Ran"
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Rhusflavone Modulates Osteoclastogenesis Through RANKL-Induced AKT Signaling in Bone Marrow-Derived Macrophages
Osteoclast differentiation inhibition is a viable treatment strategy for osteoporosis because osteoclasts play a vital role in disease progression. Rhusflavone (Rhus), a biflavonoid, exhibits a sedative–hypnotic effect via the positive allosteric modulation of GABA(A) receptors. Although several biflavonoids possess activities that help prevent bone loss, the potential effects of Rhus on osteoclastogenesis have not been reported yet. In this study, we investigated the effects and underlying biological mechanisms of Rhus isolated from the dried roots of Rhus succedanea on osteoclastogenesis in primary cultured bone marrow-derived macrophages. No cytotoxicity was observed in bone marrow macrophages (BMMs) or during osteoclast differentiation. However, Rhus reduced the number of tartrate-resistant acid phosphatase (TRAP)-positive multinuclear osteoclasts during receptor activator of nuclear factor kappa B ligand (RANKL)-induced osteoclastogenesis. The results of F-actin ring formation demonstrated that Rhus suppresses the bone resorption activity of osteoclasts. Additionally, Rhus inhibits the expression of osteoclast differentiation marker proteins, specifically c-Fos and NF-ATc1. Western blot analysis revealed that Rhus primarily attenuated RANKL-mediated key signaling pathways, particularly the AKT signaling pathway. Furthermore, we found that the AKT activator and inhibitor pharmacologically abolished and enhanced the inhibitory effects of Rhus on osteoclast differentiation, respectively. Taken together, our findings provide evidence that Rhus is a promising biologically active compound that regulates osteoclast differentiation by inhibiting the AKT signaling pathway, which may contribute to future drug development.
Effects of Scoparone on differentiation, adhesion, migration, autophagy and mineralization through the osteogenic signalling pathways
Scoparone (SCOP), an active and efficient coumarin compound derived from Artemisia capillaris Thunb, has been used as a traditional Chinese herbal medicine. Herein, we investigated the effects of SCOP on the osteogenic processes using MC3T3‐E1 pre‐osteoblasts in in vitro cell systems. SCOP (C11H10O4, > 99.17%) was purified and identified from A. capillaries. SCOP (0.1 to 100 μM concentrations) did not have cytotoxic effects in pre‐osteoblasts; however, it promoted alkaline phosphatase (ALP) staining and activity, and mineralized nodule formation under early and late osteogenic induction. SCOP elevated osteogenic signals through the bone morphogenetic protein 2 (BMP2)‐Smad1/5/8 pathway, leading to the increased expression of runt‐related transcription factor 2 (RUNX2) with its target protein, matrix metallopeptidase 13 (MMP13). SCOP also induced the non‐canonical BMP2‐MAPKs pathway, but not the Wnt3a‐β‐catenin pathway. Moreover, SCOP promoted autophagy, migration and adhesion under the osteogenic induction. Overall, the findings of this study demonstrated that SCOP has osteogenic effects associated with cell differentiation, adhesion, migration, autophagy and mineralization.
Effects of PIN on Osteoblast Differentiation and Matrix Mineralization through Runt-Related Transcription Factor
Styrax Japonica Sieb. et Zucc. has been used as traditional medicine in inflammatory diseases, and isolated compounds have shown pharmacological activities. Pinoresinol glucoside (PIN) belonging to lignins was isolated from the stem bark of S. Japonica. This study aimed to investigate the biological function and mechanisms of PIN on cell migration, osteoblast differentiation, and matrix mineralization. Herein, we investigated the effects of PIN in MC3T3-E1 pre-osteoblasts, which are widely used for studying osteoblast behavior in in vitro cell systems. At concentrations ranging from 0.1 to 100 μM, PIN had no cell toxicity in pre-osteoblasts. Pre-osteoblasts induced osteoblast differentiation, and the treatment of PIN (10 and 30 μM) promoted the cell migration rate in a dose-dependent manner. At concentrations of 10 and 30 μM, PIN elevated early osteoblast differentiation in a dose-dependent manner, as indicated by increases in alkaline phosphatase (ALP) staining and activity. Subsequently, PIN also increased the formation of mineralized nodules in a dose-dependent manner, as indicated by alizarin red S (ARS) staining, demonstrating positive effects of PIN on late osteoblast differentiation. In addition, PIN induced the mRNA level of BMP2, ALP, and osteocalcin (OCN). PIN also upregulated the protein level of BMP2 and increased canonical BMP2 signaling molecules, the phosphorylation of Smad1/5/8, and the protein level of Runt-related transcription factor 2 (RUNX2). Furthermore, PIN activated non-canonical BMP2 signaling molecules, activated MAP kinases, and increased β-catenin signaling. The findings of this study indicate that PIN has biological roles in osteoblast differentiation and matrix mineralization, and suggest that PIN might have anabolic effects in bone diseases such as osteoporosis and periodontitis.
Vanillin Promotes Osteoblast Differentiation, Mineral Apposition, and Antioxidant Effects in Pre-Osteoblasts
Antioxidant vanillin (4-hydroxy-3-methoxybenzaldehyde) is used as a flavoring in foods, beverages, and pharmaceuticals. Vanillin possesses various biological effects, such as antioxidant, anti-inflammatory, antibacterial, and anticancer properties. This study aimed to investigate the biological activities of vanillin purified from Adenophora triphylla var. japonica Hara on bone-forming processes. Vanillin treatment induced mineralization as a marker for mature osteoblasts, after stimulating alkaline phosphatase (ALP) staining and activity. The bone-forming processes of vanillin are mainly mediated by the upregulation of the bone morphogenetic protein 2 (BMP2), phospho-Smad1/5/8, and runt-related transcription factor 2 (RUNX2) pathway during the differentiation of osteogenic cells. Moreover, vanillin promoted osteoblast-mediated bone-forming phenotypes by inducing migration and F-actin polymerization. Furthermore, we validated that vanillin-mediated bone-forming processes were attenuated by noggin and DKK1. Finally, we demonstrated that vanillin-mediated antioxidant effects prevent the death of osteoblasts during bone-forming processes. Overall, vanillin has bone-forming properties through the BMP2-mediated biological mechanism, indicating it as a bone-protective compound for bone health and bone diseases such as periodontitis and osteoporosis.
Low-dose CBCT reconstruction via joint non-local total variation denoising and cubic B-spline interpolation
This study develops an improved Feldkamp–Davis–Kress (FDK) reconstruction algorithm using non-local total variation (NLTV) denoising and a cubic B-spline interpolation-based backprojector to enhance the image quality of low-dose cone-beam computed tomography (CBCT). The NLTV objective function is minimized on all log-transformed projections using steepest gradient descent optimization with an adaptive control of the step size to augment the difference between a real structure and noise. The proposed algorithm was evaluated using a phantom data set acquired from a low-dose protocol with lower milliampere-seconds (mAs).The combination of NLTV minimization and cubic B-spline interpolation rendered the enhanced reconstruction images with significantly reduced noise compared to conventional FDK and local total variation with anisotropic penalty. The artifacts were remarkably suppressed in the reconstructed images. Quantitative analysis of reconstruction images using low-dose projections acquired from low mAs showed a contrast-to-noise ratio with spatial resolution comparable to images reconstructed using projections acquired from high mAs. The proposed approach produced the lowest RMSE and the highest correlation. These results indicate that the proposed algorithm enables application of the conventional FDK algorithm for low mAs image reconstruction in low-dose CBCT imaging, thereby eliminating the need for more computationally demanding algorithms. The substantial reductions in radiation exposure associated with the low mAs projection acquisition may facilitate wider practical applications of daily online CBCT imaging.
Chitinase 3 like 1 suppresses the stability and activity of p53 to promote lung tumorigenesis
Background Chitinase 3 like 1 protein (Chi3L1) is expressed in several cancers, and a few evidences suggest that the secreted Chi3L1 contributes to tumor development. However, the molecular mechanisms of intracellular Chi3L1 are unknown in the lung tumor development. Methods: In the present study, we generated Chi3L1 knockout mice (Chi3L1 KO(−/−) ) using CRISPR/Cas9 system to investigate the role of Chi3L1 on lung tumorigenesis. Results We established lung metastasis induced by i.v. injections of B16F10 in Chi3L1 KO(−/−) . The lung tumor nodules were significantly reduced in Chi3L1 KO(−/−) and protein levels of p53, p21, BAX, and cleaved-caspase 3 were significantly increased in Chi3L1 KO(−/−) , while protein levels of cyclin E1, CDK2, and phsphorylation of STAT3 were decreased in Chi3L1 KO(−/−) . Allograft mice inoculated with B16F10 also suppressed tumor growth and increased p53 and its target proteins including p21 and BAX. In addition, knockdown of Chi3L1 in lung cancer cells inhibited lung cancer cell growth and upregulated p53 expression with p21 and BAX, and a decrease in phosphorylation of STAT3. Furthermore, we found that intracellular Chi3L1 physically interacted and colocalized with p53 to inhibit its protein stability and transcriptional activity for target genes related with cell cycle arrest and apoptosis. In lung tumor patient, we clinically found that Chi3L1 expression was upregulated with a decrease in p53 expression, as well as we validated that intracellular Chi3L1 was colocalized, reversely expressed, and physically interacted with p53, which results in suppression of the expression and function of p53 in lung tumor patient. Conclusions Our studies suggest that intracellular Chi3L1 plays a critical role in the lung tumorigenesis by regulating its novel target protein, p53 in both an in vitro and in vivo system.
Trifloroside Induces Bioactive Effects on Differentiation, Adhesion, Migration, and Mineralization in Pre-Osteoblast MC3T3E-1 Cells
Gentianae Scabrae Radix is used in traditional medicine and is known to possess bioactive compounds, including secoiridoid glycosides, flavonoids, lignans, and triterpenes. Trifloroside (TriFs) is a secoiridoid glycoside known for its antioxidant activity; however, its other effects have not been studied. In the present study, we investigated the biological effects of TriFs isolated from the roots of Gentianae Scabrae Radix using pre-osteoblast MC3T3E-1 cells. No cellular toxicity was observed with 1 μM TriFs, whereas 5–100 μM TriFs showed a gradual increase in cell viability. Alkaline phosphatase staining and microscopic observations revealed that 1–10 μM TriFs stimulated osteogenic activity during early osteoblast differentiation. Trifloroside also increased mineral apposition during osteoblast maturation. Biochemical analyses revealed that TriFs promoted nuclear RUNX2 expression and localization by stimulating the major osteogenic BMP2-Smad1/5/8-RUNX2 pathway. Trifloroside also increased p-GSK3β, β-catenin, p-JNK, and p-p38, but not Wnt3a, p-AKT, and p-ERK. Moreover, TriFs increased the MMP13 levels and promoted cell migration and adhesion. In contrast, TriFs-induced osteoblast differentiation and maturation had negligible effects on autophagy and necrosis. Our findings suggest that TriFs induces osteogenic effects through differentiation, adhesion, migration, and mineral apposition. Therefore, TriFs is suggested as a potential drug target in osteoblast-mediated bone diseases.
Loss of parkin reduces lung tumor development by blocking p21 degradation
Several epidemiological studies have demonstrated the reciprocal relationship between the development of cancer and Parkinson's disease (PD). However, the possible mechanisms underlying this relationship remain unclear. To identify this relationship, we first compared lung tumor growth in parkin knockout (KO) mice and wild-type (WT) mice. Parkin KO mice showed decreased lung tumor growth and increased expression of p21, a cell cycle arrester, as compared with WT mice. We also found that parkin interacts with p21, resulting in its degradation; however, parkin KO, knockdown, as well as mutation (R275W or G430D) reduced the degradation of p21. We investigated whether parkin KO increases the association of p21 with proliferating cell nuclear antigen (PCNA) or CDK2 by reducing p21 degradation, and, thus, arresting the cell cycle. The interaction between p21 and PCNA or CDK2 was also enhanced by parkin knockdown, and this increased interaction induced sub G0/G1 arrest, leading to cell death. Therefore, our data indicate that parkin KO reduces the development of lung tumors via cell cycle arrest by blocking the degradation of p21. These findings suggest that PD could be associated with lower lung cancer incidence.
Magnetic Nanocomposite Scaffold-Induced Stimulation of Migration and Odontogenesis of Human Dental Pulp Cells through Integrin Signaling Pathways
Magnetism is an intriguing physical cue that can alter the behaviors of a broad range of cells. Nanocomposite scaffolds that exhibit magnetic properties are thus considered useful 3D matrix for culture of cells and their fate control in repair and regeneration processes. Here we produced magnetic nanocomposite scaffolds made of magnetite nanoparticles (MNPs) and polycaprolactone (PCL), and the effects of the scaffolds on the adhesion, growth, migration and odontogenic differentiation of human dental pulp cells (HDPCs) were investigated. Furthermore, the associated signaling pathways were examined in order to elucidate the molecular mechanisms in the cellular events. The magnetic scaffolds incorporated with MNPs at varying concentrations (up to 10%wt) supported cellular adhesion and multiplication over 2 weeks, showing good viability. The cellular constructs in the nanocomposite scaffolds played significant roles in the stimulation of adhesion, migration and odontogenesis of HDPCs. Cells were shown to adhere to substantially higher number when affected by the magnetic scaffolds. Cell migration tested by in vitro wound closure model was significantly enhanced by the magnetic scaffolds. Furthermore, odontogenic differentiation of HDPCs, as assessed by the alkaline phosphatase activity, mRNA expressions of odontogenic markers (DMP-1, DSPP,osteocalcin, and ostepontin), and alizarin red staining, was significantly stimulated by the magnetic scaffolds. Signal transduction was analyzed by RT-PCR, Western blotting, and confocal microscopy. The magnetic scaffolds upregulated the integrin subunits (α1, α2, β1 and β3) and activated downstream pathways, such as FAK, paxillin, p38, ERK MAPK, and NF-κB. The current study reports for the first time the significant impact of magnetic scaffolds in stimulating HDPC behaviors, including cell migration and odontogenesis, implying the potential usefulness of the magnetic scaffolds for dentin-pulp tissue engineering.
Effect of Spicatoside a on Anti-Osteosarcoma MG63 Cells through Reactive Oxygen Species Generation and the Inhibition of the PI3K-AKT-mTOR Pathway
Osteosarcoma is a primary malignant tumor found in the bones of children and adolescents. Unfortunately, many patients do not respond well to treatment and succumb to the illness. Therefore, it is necessary to discover novel bioactive compounds to overcome therapeutic limitations. Liriope platyphylla Wang et Tang is a well-known herb used in oriental medicine. Studies have shown that metabolic diseases can be clinically treated using the roots of L. platyphylla. Recent studies have demonstrated the anticarcinoma potential of root extracts; however, the exact mechanism remains unclear. The aim of this study was to examine the anti-osteosarcoma activity of a single compound extracted from the dried roots of L. platyphylla. We purified Spicatoside A (SpiA) from the dried roots of L. platyphylla. SpiA significantly inhibited the proliferation of human osteosarcoma MG63 cells in a dose- and time-dependent manner. SpiA also regulated the expression of various downstream proteins that mediate apoptosis (PARP, Bcl-2, and Bax), cell growth (cyclin D1, Cdk4, and Cdk6), angiogenesis (VEGF), and metastasis (MMP13). The Proteome Profiler Human Phospho-Kinase Array Kit showed that the AKT signaling protein was a target of SpiA in osteosarcoma cells. We also found that SpiA suppressed the constitutive activation of the PI3K-AKT-mTOR-p70S6K1 signaling pathway. We further validated the effects of SpiA on the AKT signaling pathway. SpiA induced autophagosome formation and suppressed necroptosis (a form of programmed cell death). SpiA increased the generation of reactive oxygen species (ROS) and led to the loss of mitochondrial membrane potential. N-acetylcysteine (NAC)-induced inhibition of ROS generation reduced SpiA-induced AKT inhibition, apoptotic cell death, and anti-metastatic effects by suppressing cell migration and invasion. Overall, these results highlight the anti-osteosarcoma effect of SpiA by inhibiting the AKT signaling pathway through ROS generation, suggesting that SpiA may be a promising compound for the treatment of human osteosarcoma.