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1.
Int J Oncol ; 62(1)2023 01.
Article in English | MEDLINE | ID: mdl-36453252

ABSTRACT

Endothelin receptor A (EDNRA) has been reported to play various crucial physiological roles and has been shown to be associated with the pathology of several diseases, including colorectal cancer (CRC). However, the molecular mechanisms of EDNRA in the development of human CRC have not been fully elucidated to date. In this context, the present study was performed to investigate biological functions and novel downstream signaling pathways affected by EDNRA, during CRC progression. First, using public data repositories, it was observed that the EDRNA expression levels were markedly increased in CRC tissues, as compared to normal tissues. Patients with CRC with an increased EDNRA expression exhibited a significantly decreased survival rate in comparison with those with a lower EDNRA expression. Furthermore, a positive correlation between the levels of EDNRA and its ligand, EDN1, was found in CRC tissues. The ectopic expression of EDNRA or its ligand, EDN1, promoted, whereas the silencing of EDNRA or EDN1 decreased cell proliferation and migration in vitro. To elucidate the signaling pathways involved in the regulation of EDNRA expression in CRC cells, a phosphokinase array analysis was performed, and it was observed that the knockdown of EDNRA substantially suppressed the phosphorylation of signal transducer and activator of transcription 3 (STAT3) in CRC cells. Of note, STAT3 silencing simultaneously decreased EDN1 and EDNRA expression, with the expression of EDN1 and/or EDNRA appearing to be directly regulated by binding STAT3 to their promoter region, according to chromatin immunoprecipitation and promoter assays, ultimately indicating a positive feedback loop in the expression of EDNRA and EDN1. It was also observed that treatment with an EDNRA antagonist (macitentan), alone or in combination with cisplatin, suppressed cell growth and migration ability, and induced cell apoptosis. Collectively, these data suggest a critical role of the EDN1/EDNRA signaling pathway in CRC progression. Thus, the pharmacological intervention of this signaling pathway may prove to be a potential therapeutic approach for patients with CRC.


Subject(s)
Colorectal Neoplasms , STAT3 Transcription Factor , Humans , Phosphorylation , STAT3 Transcription Factor/genetics , beta-Arrestins , Receptors, Endothelin , Ligands , Colorectal Neoplasms/genetics
2.
ACS Appl Mater Interfaces ; 14(28): 32319-32329, 2022 Jul 20.
Article in English | MEDLINE | ID: mdl-35816704

ABSTRACT

The high design flexibility of organic semiconductors should lead to diverse and complex electronic functions. However, currently available high-performance organic semiconductors are limited in variety; most of p-type materials are based on thienoacenes or related one-dimensionally (1D) extended π-conjugated systems. In an effort to expand the diversity of organic semiconductors, we are working on the development of tetrabenzoporphyrin (BP) derivatives as active-layer components of organic electronic devices. BP is characterized by its large, rigid two-dimensionally (2D) extended π-framework with high light absorptivity and therefore is promising as a core building unit of organic semiconductors for optoelectronic applications. Herein, we demonstrate that BP derivatives can afford field-effect hole mobilities of >4 cm2 V-1 s-1 upon careful tuning of substituents. Comparative analysis of a series of 5,15-bis(n-alkyldimethylsilylethynyl)tetrabenzoporphyrins reveals that linear alkyl substituents disrupt the π-π stacking of BP cores, unlike the widely observed "fastener effect" for 1D extended π-systems. The n-octyl and n-dodecyl groups have the best balance between high solution processability and minimal π-π stacking disruption, leading to superior hole mobilities in solution-processed thin films. The resulting thin films show high thermal stability wherein the field-effect hole mobility stays above 1 cm2 V-1 s-1 even after heating at 160 °C in air, reflecting the tight packing of large BP units. These findings will serve as a good basis for extracting the full potential of 2D extended π-frameworks and thus for increasing the structural or functional diversities of high-performance organic semiconductors.

3.
Public Health Pract (Oxf) ; 3: 100241, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35252902

ABSTRACT

OBJECTIVES: This study examined the influence of COVID-19 on the perception and behaviours of hygiene practices for food safety in South Korea. STUDY DESIGN: This study employed COVID-19 status (i.e. before or after the outbreak), gender and age groups as independent variables, and perceived relevance and behaviour frequency of hygiene practices for food safety as dependent variables. METHODS: Respondents were asked to answer questions about the perceived relevance and behaviour frequency of hygiene practices before and after the COVID-19 outbreak in an online survey with a structured questionnaire. RESULTS: Respondents' perceived relevance and behaviour frequency of hygiene practices increased after the COVID-19 outbreak. This trend was seen in both genders and across all age groups. In addition, the enhanced perception that hygiene practices are related to food safety had a strong relationship with following hygiene practices. CONCLUSIONS: The findings of this study indicate that COVID-19 made people more aware of maintaining personal hygiene, leading to a noticeable change in the food safety environment, and subsequently prevention of viral transmission. In particular, the COVID-19 outbreak has influenced the communal eating culture by highlighting good hygiene practices, such as taking individual servings of food from communal dishes and using personal plates.

4.
ISME J ; 16(5): 1205-1221, 2022 05.
Article in English | MEDLINE | ID: mdl-34972816

ABSTRACT

The human microbiome plays an essential role in the human immune system, food digestion, and protection from harmful bacteria by colonizing the human intestine. Recently, although the human microbiome affects colorectal cancer (CRC) treatment, the mode of action between the microbiome and CRC remains unclear. This study showed that propionate suppressed CRC growth by promoting the proteasomal degradation of euchromatic histone-lysine N-methyltransferase 2 (EHMT2) through HECT domain E3 ubiquitin protein ligase 2 (HECTD2) upregulation. In addition, EHMT2 downregulation reduced the H3K9me2 level on the promoter region of tumor necrosis factor α-induced protein 1 (TNFAIP1) as a novel direct target of EHMT2. Subsequently, TNFAIP1 upregulation induced the apoptosis of CRC cells. Furthermore, using Bacteroides thetaiotaomicron culture medium, we confirmed EHMT2 downregulation via upregulation of HECTD2 and TNFAIP1 upregulation. Finally, we observed the synergistic effect of propionate and an EHMT2 inhibitor (BIX01294) in 3D spheroid culture models. Thus, we suggest the anticancer effects of propionate and EHMT2 as therapeutic targets for colon cancer treatment and may provide the possibility for the synergistic effects of an EHMT2 inhibitor and microbiome in CRC treatment.


Subject(s)
Colorectal Neoplasms , Microbiota , Ubiquitin-Protein Ligases/metabolism , Histocompatibility Antigens/metabolism , Histone-Lysine N-Methyltransferase/genetics , Histone-Lysine N-Methyltransferase/metabolism , Humans , Propionates , Up-Regulation
5.
BMC Cancer ; 20(1): 1180, 2020 Dec 02.
Article in English | MEDLINE | ID: mdl-33267790

ABSTRACT

BACKGROUND: Anchoring filament protein ladinin-1 (LAD1) was related to the aggressive progression of breast, lung, laryngeal and thyroid cancers. However, the association of LAD1 with colorectal cancer remained unknown. Here, to determine the relationship of LAD1 with colorectal cancer progression, we explored the effect of LAD1 loss on the malignant features of colorectal cancer cells. METHODS: We constructed LAD1-depleted cell lines and examined the effect of LAD1 deficiency on the phenotypic and molecular features of colorectal cancer cells in vitro. The function of LAD1 in metastasis in vivo was examined by establishing a spleen-to-liver metastasis mouse model. LAD1 protein expression in colorectal cancer patient specimens was assessed by immunohistochemistry of tumor microarrays. RESULTS: We found that LAD1 was abundant in most colorectal cancer cells. In addition, high expression of LAD1 significantly correlated with poor patient outcome. LAD1 depletion inhibited the migration and invasion of two different colorectal cancer cell lines, SW620 and Caco-2, without affecting their proliferation. In addition, LAD1 loss led to defects in liver metastasis of SW620 cells in the mouse model. Immunohistochemistry of colorectal cancer tissues revealed LAD1 enrichment in metastatic tissues compared to that in primary tumor and normal tissues. CONCLUSION: These results suggest that LAD1 expression is associated with the metastatic progression of colorectal cancer by promoting the migration and invasion of cancer cells.


Subject(s)
Autoantigens/metabolism , Colorectal Neoplasms/metabolism , Non-Fibrillar Collagens/metabolism , Animals , Colorectal Neoplasms/mortality , Female , Mice , Neoplasm Metastasis , Survival Analysis , Transfection , Collagen Type XVII
6.
Int J Mol Sci ; 21(21)2020 Nov 07.
Article in English | MEDLINE | ID: mdl-33171878

ABSTRACT

Mesenchymal stem cells (MSCs) are multipotent stem cells that can be isolated from various tissues in the adult body. MSCs should be characterized by three criteria for regenerative medicine. MSCs must (1) adhere to plastic surfaces, (2) express specific surface antigens, and (3) differentiate into mesodermal lineages, including chondrocytes, osteoblasts, and adipocytes, in vitro. Interestingly, MSCs have immunomodulatory features and secrete trophic factors and immune receptors that regulate the microenvironment in host tissue. These specific and unique therapeutic properties make MSCs ideal as therapeutic agents in vivo. Specifically, pre-clinical and clinical investigators generated inflammatory and fibrotic diseases models, and then transplantation of MSCs into diseases models for therapeutic effects investigation. In this review, we characterize MSCs from various tissues and describe their applications for treating various inflammation and fibrotic diseases.


Subject(s)
Fibrosis/therapy , Inflammation/therapy , Mesenchymal Stem Cells/metabolism , Adipocytes/cytology , Animals , Cell Differentiation , Chondrocytes/cytology , Humans , Mesenchymal Stem Cell Transplantation/methods , Mesenchymal Stem Cells/cytology , Osteoblasts/cytology , Regenerative Medicine/methods
7.
Int J Mol Sci ; 21(6)2020 Mar 13.
Article in English | MEDLINE | ID: mdl-32183071

ABSTRACT

Mesenchymal stem cells, also known as multipotent stromal progenitor cells, can differentiate into cells of mesodermal lineage. Gangliosides are sialic acid-conjugated glycosphingolipids that are believed to regulate cell differentiation and several signaling molecules. These molecules are localized in glycosphingolipid-enriched microdomains on the cell surface and are regulated by glycosphingolipid composition. Transforming growth factor-beta (TGF-ß) signaling plays a critical role in chondrogenic differentiation. However, the role of gangliosides in chondrogenesis is not understood. In this study, the relationship between the ganglioside GM3 and TGF-ß activation, during chondrogenic differentiation, was investigated using an aggregate culture of human synovial membrane-derived mesenchymal stem cells. We showed that the gangliosides GM3 and GD3 were expressed after the chondrogenic differentiation of hSMSC aggregates. To test whether GM3 affected the chondrogenic differentiation of hSMSC aggregates, we used GM3 treatment during chondrogenic differentiation. The results showed that the group treated with 5 µM GM3 had higher expression of chondrogenic specific markers, increased toluidine blue, and safranin O staining, and increased accumulation of glycosaminoglycans compared with the untreated group. Furthermore, GM3 treatment enhanced TGF-ß signaling via SMAD 2/3 during the chondrogenic differentiation of hSMSC aggregates. Taken together, our results suggested that GM3 may be useful in developing therapeutic agents for cell-based articular cartilage regeneration in articular cartilage disease.


Subject(s)
Cell Differentiation , Chondrocytes/metabolism , G(M3) Ganglioside/pharmacology , Mesenchymal Stem Cells/metabolism , Receptors, Transforming Growth Factor beta/metabolism , Cells, Cultured , Chondrocytes/cytology , Chondrogenesis , Glycosaminoglycans/metabolism , Humans , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/drug effects , Signal Transduction , Smad Proteins/metabolism , Synovial Membrane/cytology , Transforming Growth Factor beta/metabolism , Up-Regulation
8.
J Org Chem ; 85(1): 168-178, 2020 Jan 03.
Article in English | MEDLINE | ID: mdl-31711287

ABSTRACT

Tetrabenzoporphyrin (BP) holds attractive characteristics for optoelectronic applications, such as the large π-conjugated framework and high photoabsorption capability. However, its use in organic solar cells (OSCs) has been limited because of the extremely low solubility that hampers direct solution processing and also the high frontier-orbital energies that lead to low open-circuit voltage (VOC). Herein, we examine BP derivatives equipped with multiple strongly electron-withdrawing groups for photovoltaic applications. The derivatives are generated in thin films through a thermal precursor approach, wherein the corresponding bicyclo[2.2.2]octadiene-fused porphyrin derivatives are solution-cast, and then annealed to carry out the in situ retro-Diels-Alder reaction. The frontier-orbital energies of the resulting derivatives are effectively stabilized as compared to pristine BP to such a degree that they afford high VOC of up to 0.94 V when used as a donor or can even work as a new class of nonfullerene acceptor in OSCs. Single-crystal X-ray diffraction analyses demonstrate that the conformation of the BP framework largely varies from being near planar to highly curved depending on its substituents. The morphology of polymer:BP-derivative bulk-heterojunction films prepared by the thermal precursor approach also varies between the BP derivatives. These results can greatly extend the scope of both molecular design and morphology control for utilization of the BP chromophore toward achieving viable organic optoelectronic devices.

9.
Genes (Basel) ; 10(11)2019 11 08.
Article in English | MEDLINE | ID: mdl-31717435

ABSTRACT

Increasing evidence has demonstrated that increased expression of cyclin-dependent kinase regulatory subunit 1B (CKS1B) is associated with the pathogenesis of many human cancers, including colorectal cancer (CRC). However, the regulatory mechanisms underlying the expression of CKS1B in CRC are not completely understood. Here, we investigate the role played by microRNAs in the expression of CKS1B and carcinogenesis in CRC. Among the six microRNAs predicted to target CKS1B gene expression, only miR-1258 was revealed to downregulate CKS1B expression through binding to its 3'-UTR region, as ectopic miR-1258 expression suppressed CKS1B expression and vice versa. In CRC, miR-1258 expression also decreased cell proliferation and migration in vitro and tumor growth in vivo, similar to cells with silenced CKS1B expression. Considering the highly increased levels of CKS1B and decreased expression of miR-1258 in tumors from CRC patients, these findings suggest that miR-1258 may play tumor-suppressive roles by targeting CKS1B expression in CRC. However, the therapeutic significance of these findings should be evaluated in clinical settings.


Subject(s)
CDC2-CDC28 Kinases/genetics , Colorectal Neoplasms/genetics , MicroRNAs/genetics , Animals , CDC2-CDC28 Kinases/metabolism , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Female , Gene Expression Regulation, Neoplastic , HEK293 Cells , HT29 Cells , Humans , Mice , Mice, Inbred BALB C , MicroRNAs/metabolism , Xenograft Model Antitumor Assays
10.
Biochem Biophys Res Commun ; 508(1): 275-281, 2019 01 01.
Article in English | MEDLINE | ID: mdl-30497779

ABSTRACT

Precise cell cycle regulation is critical to prevent aberrant cell proliferation and cancer progression. Cks1 was reported to be an essential accessory factor for SCFSkp2, the ubiquitin ligase that targets p27Kip1 for proteasomal degradation; these actions drive mammalian cell transition from G1 to S phase. In this study, we investigated the role played by Cks1 in the growth and progression of human hepatocellular carcinoma (HCC) cells. Silencing Cks1 expression abrogated osteopontin (OPN) expression in a p27Kip1-dependent manner in Huh7 HCC cells. OPN increased the proliferation, migration and invasion of Huh7 cells. Pharmacological inhibitor studies demonstrated that ERK1/2 signaling is responsible mainly for Cks1-mediated OPN expression. Cks1 appears to regulate ERK1/2 signaling through the expression of dual-specificity phosphatase 16 (DUSP16) because both Cks1 knockdown, which leads to DUSP16 upregulation, and DUSP16 overexpression decreased ERK1/2 phosphorylation and the resulting OPN expression. The same is true for the Cks1-mediated increases in p27Kip1, suggesting that Cks1 regulates OPN expression through activating ERK1/2 signaling either by suppressing DUSP16 expression or by a p27Kip1-dependent mechanism. Cks1 and OPN expression levels were significantly higher, but DUSP16 expression levels were significantly lower in HCC tissues than in normal liver tissues. Both Cks1 and OPN expression were negatively correlated with DUSP16 expression, whereas Cks1 expression was positively correlated with OPN expression. Moreover, combined panels for the expression levels of Cks1, DUSP16 and OPN showed significant prognostic power for the risk assessment of HCC patient overall survival. In conclusion, our data propose a novel function for Cks1 as a tumor promoter through the expression of the strongly oncogenic protein OPN in HCC.


Subject(s)
CDC2-CDC28 Kinases/metabolism , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Osteopontin/biosynthesis , Osteopontin/genetics , Cell Line, Tumor , Cell Proliferation , Humans , Liver Neoplasms/diagnosis , Osteopontin/metabolism
11.
BMB Rep ; 50(6): 341, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28651685

ABSTRACT

The BMB Reports would like to correct in the ACKNOWLEDGEMENTS of BMB Rep. 45(12), 713-718 titled "Ganglioside GM1 influences the proliferation rate of mouse induced pluripotent stem cells".

12.
Explore (NY) ; 13(3): 218-221, 2017.
Article in English | MEDLINE | ID: mdl-28343768

ABSTRACT

Conventional treatments do not appreciably improve fecundity in women with extremely low-serum levels of anti-Müllerian hormone (AMH). In Korea, herbal medicine is widely used to treat female infertility. We report a case in which an infertile woman with a very low AMH level naturally conceived after two months of herbal treatment (Bogungsamul-tang), ultimately giving birth to a full-term baby. Although AMH levels were not measured immediately before and after treatment, our study suggests that Korean herbal remedies are a viable option for infertile women with negligible AMH levels. Further studies should be performed to fully assess the clinical effects of Bogungsamul-tang in such women.


Subject(s)
Anti-Mullerian Hormone/blood , Infertility, Female/drug therapy , Live Birth , Phytotherapy , Adult , Female , Humans , Medicine, Korean Traditional , Pregnancy , Treatment Outcome
13.
Food Sci Biotechnol ; 26(2): 363-368, 2017.
Article in English | MEDLINE | ID: mdl-30263551

ABSTRACT

A method for analyzing the contents of residual hexane in health functional food products was developed. The dissolving solvents in the health functional food products and the internal standard selected were N,N-dimethylacetamide and heptane, respectively. The analysis conditions for headspace-gas chromatography/flame ionization detection (HS-GC/FID) and headspace-gas chromatography/mass spectrometry (HS-GC/MS) were determined as 18 mL of headspace volume, 100°C of headspace oven temperature, and 30 min of equilibration time; a Durabond (DB)-624 column was selected for this analysis. To validate this method, which applies N,N-dimethylacetamide as a dissolving solvent, the limit of detection and limit of quantification (LOQ) values based on the HS-GC/FID and HS-GC/MS analyses results were found to be 0.10, 0.29 and 0.16, 0.47 mg/L, respectively. The recoveries and coefficient of variation (CV) obtained by HS-GC/MS were 96.39-119.86% and 0.04-1.25%, respectively, better than those obtained by HS-GC/FID. By applying the HS-GC/MS method, it was possible to analyze the content of the residual hexane in 60 different types of health functional food products.

14.
Biochem Biophys Res Commun ; 478(1): 403-409, 2016 09 09.
Article in English | MEDLINE | ID: mdl-27422607

ABSTRACT

The heterogeneity and genetic instability of ovarian cancer cells often lead to the development of drug resistance, closely related with the increased cancer-related mortality. In this study, we investigated the role of dual-specificity phosphatase 1 (DUSP1) in the development of the resistance in human ovarian cancer cells against paclitaxel. Overexpression of DUSP1 in HeyA8 human ovarian cancer cells (HeyA8-DUSP1) up-regulated the expression of the drug efflux pump, p-glycoprotein. Consequently, HeyA8-DUSP1 cells are highly resistant to paclitaxel, with the resistance comparable to that of a multi-drug resistance cell line (HeyA8-MDR). Moreover, over expression of DUSP1 significantly increased the activation of p38 MAPK, leaving the activation of ERK1/2 and JNK1/2 unaffected. Pharmacological suppression of p38 MAPK activity prevents the up-regulation of p-glycoprotein expression and the consequent resistance against paclitaxel in HeyA8-DUSP1 cells. By contrast, HeyA8-MDR cells expressed a significantly higher level of DUSP1, but treatment with small interference RNA against DUSP1 significantly suppressed the expression of p-glycoprotein and the resistance against paclitaxel in HeyA8-MDR cells. Ectopic expression of MKK3, an upstream activator of p38 MAPK, significantly up-regulated the expression of p-glycoprotein and increased the consequent resistance against paclitaxel in HeyA8 cells. Collectively, these data indicated that DUSP1 may induce the resistance against paclitaxel through the p38 MAPK-mediated overexpression of p-glycoprotein in human ovarian cancer cells.


Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Dual Specificity Phosphatase 1/metabolism , MAP Kinase Signaling System/drug effects , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/metabolism , Paclitaxel/administration & dosage , Antineoplastic Agents, Phytogenic/administration & dosage , Apoptosis/drug effects , Cell Line, Tumor , Drug Resistance, Neoplasm/physiology , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , Ovarian Neoplasms/pathology , Treatment Outcome
15.
BMB Rep ; 45(12): 713-8, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23261057

ABSTRACT

Gangliosides play important roles in the control of several biological processes, including proliferation and transmembrane signaling. In this study, we demonstrate the effect of ganglioside GM1 on the proliferation of mouse induced pluripotent stem cells (miPSCs). The proliferation rate of miPSCs was lower than in mouse embryonic stem cells (mESCs). Fluorescence activated cell sorting analysis showed that the percentage of cells in the G2/M phase in miPSCs was lower than that in mESCs. GM1 was expressed in mESCs, but not miPSCs. To confirm the role of GM1 in miPSC proliferation, miPSCs were treated with GM1. GM1-treated miPSCs exhibited increased cell proliferation and a larger number of cells in the G2/M phase. Furthermore, phosphorylation of mitogen-activated protein kinases was increased in GM1- treated miPSCs.


Subject(s)
Cell Proliferation/drug effects , G(M1) Ganglioside/pharmacology , Induced Pluripotent Stem Cells/cytology , Animals , Cells, Cultured , Embryonic Stem Cells/cytology , Embryonic Stem Cells/metabolism , Flow Cytometry , G2 Phase Cell Cycle Checkpoints/drug effects , Induced Pluripotent Stem Cells/metabolism , M Phase Cell Cycle Checkpoints/drug effects , MAP Kinase Signaling System , Mice
16.
Biochem Biophys Res Commun ; 424(4): 765-70, 2012 Aug 10.
Article in English | MEDLINE | ID: mdl-22809505

ABSTRACT

Somatic cell nuclear transfer (SCNT) has been established for the transmission of specific nuclear DNA. However, the fate of donor mitochondrial DNA (mtDNA) remains unclear. Here, we examined the fate of donor mtDNA in recloned pigs through third generations. Fibroblasts of recloned pigs were obtained from offspring of each generation produced by fusion of cultured fibroblasts from a Minnesota miniature pig (MMP) into enucleated oocytes of a Landrace pig. The D-loop regions from the mtDNA of donor and recipient differ at nucleotide sequence positions 16050 (A→T), 16062 (T→C), and 16135 (G→A). In order to determine the fate of donor mtDNA in recloned pigs, we analyzed the D-loop region of the donor's mtDNA by allele-specific PCR (AS-PCR) and real-time PCR. Donor mtDNA was successfully detected in all recloned offspring (F1, F2, and F3). These results indicate that heteroplasmy that originate from donor and recipient mtDNA is maintained in recloned pigs, resulting from SCNT, unlike natural reproduction.


Subject(s)
Cloning, Organism , DNA, Mitochondrial/genetics , Nuclear Transfer Techniques , Swine, Miniature/genetics , Animals , Base Sequence , DNA, Mitochondrial/analysis , DNA, Mitochondrial/chemistry , Fibroblasts/metabolism , Molecular Sequence Data , Nucleic Acid Conformation , Oocytes/metabolism , Swine
17.
Biochem Biophys Res Commun ; 387(2): 266-71, 2009 Sep 18.
Article in English | MEDLINE | ID: mdl-19580786

ABSTRACT

Human dental pulp-derived stem cells (hDPSCs) have been considered alternative sources of adult stem cells because of their potential to differentiate into multiple cell lineages. This study investigated the possible role of gangliosides in the neural differentiation of hDPSCs. When hDPSCs were cultured under neural differentiation conditions, expression of neural cell marker genes such as Nestin, MAP-2, and NeuN was detected. Immunostaining and high-performance thin-layer chromatography analysis showed that an increase in ganglioside biosynthesis was associated with neural differentiation of hDPSCs. Specifically, a significant increase in GD3 and GD1a expression was observed during neural differentiation. To confirm the role of gangliosides in neural differentiation, ganglioside biosynthesis was inhibited in hDPSCs by knockdown of UDP-glucose ceramide glucosyltransferase (Ugcg), which prevented differentiation into neural cells. These results suggest that gangliosides may play a role in the neural differentiation process of hDPSCs.


Subject(s)
Dental Pulp/cytology , Gangliosides/biosynthesis , Neurogenesis , Stem Cells/cytology , Cell Line , Dental Pulp/metabolism , Gangliosides/antagonists & inhibitors , Gene Knockdown Techniques , Glucosyltransferases/antagonists & inhibitors , Glucosyltransferases/genetics , Humans , Stem Cells/metabolism
18.
Int J Radiat Oncol Biol Phys ; 73(4): 1196-202, 2009 Mar 15.
Article in English | MEDLINE | ID: mdl-19251091

ABSTRACT

PURPOSE: Human peroxiredoxins (Prxs) are known as a family of thiol-specific antioxidant enzymes, among which Prx-I and -II play an important role in protecting cells from irradiation-induced cell death. It is not known whether Prx-IV also protects cells from ionizing radiation (IR). METHODS AND MATERIALS: To evaluate the protective role of Prx-IV in IR, we transfected full-length Prx-IV cDNA into AMC-HN3 cells, which weakly express endogenous Prx-IV, and knocked down the expression of Prx-IV with siRNA methods using AMC-HN7 cells, which express high levels of endogenous Prx-IV. Radiosensitivity profiles in these cells were evaluated using clonogenic assay, FACS analysis, cell viability, and TUNEL assay. RESULTS: Three Prx-IV expressing clones were isolated. Prx-IV regulated intracellular reactive oxygen species (ROS) levels and made cells more resistant to IR-induced apoptosis. Furthermore, the knockdown of Prx-IV with siRNA made cells more sensitive to IR-induced apoptosis. CONCLUSION: The results of these studies suggest that Prx-IV may play an important role in protecting cells from IR-induced apoptosis in head-and-neck squamous cell carcinoma.


Subject(s)
Apoptosis/physiology , Carcinoma, Squamous Cell/radiotherapy , Head and Neck Neoplasms/radiotherapy , Peroxiredoxins/physiology , Radiation Tolerance/physiology , Apoptosis/radiation effects , Carcinoma, Squamous Cell/physiopathology , Cell Line, Tumor , Gene Knockdown Techniques , Head and Neck Neoplasms/physiopathology , Humans , Peroxiredoxins/genetics , Radiation Tolerance/genetics , Reactive Oxygen Species/analysis , Transfection/methods
19.
Ann Dermatol ; 21(4): 364-8, 2009 Nov.
Article in English | MEDLINE | ID: mdl-20523825

ABSTRACT

BACKGROUND: The characterization of progenitor/keratinocyte stem cells (KSC) remains an unachieved goal. A previous study showed that rapid adhering cells to collagen IV had the characteristics of putative progenitor/KSCs. OBJECTIVE: The purpose of this study was to investigate the genetic expression of rapid adhering cells compared to non adhering cells to determine the characteristic of KSCs. METHODS: We isolated rapid adhering cells representative of KSCs from non adhering cells representative of transient amplifying cells. In addition, we differentiated cells from human tonsilar keratinocytes utilizing the adhering capability of the KSCs to collagen IV. Annealing control primer based differentially displayed polymerase chain reaction (PCR) was performed as well as Western blot analysis. RESULTS: The levels of mitochondria-related gene expression were low in the rapid adhering cells compared to the non adhering cells. Mitochondrial complex I, COX IV, peroxiredoxins (I, II and IV) and mitochondrial membrane potential were all low in the rapid adhering cells compared to the non adhering cells. CONCLUSION: Using an adhesion method on human collagen IV-coated plates, our results suggest that reduced mitochondrial function may be an important characteristic of KSCs.

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