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1.
BMC Bioinformatics ; 25(1): 101, 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38448845

ABSTRACT

PURPOSE: The expansion of research across various disciplines has led to a substantial increase in published papers and journals, highlighting the necessity for reliable text mining platforms for database construction and knowledge acquisition. This abstract introduces GPDMiner(Gene, Protein, and Disease Miner), a platform designed for the biomedical domain, addressing the challenges posed by the growing volume of academic papers. METHODS: GPDMiner is a text mining platform that utilizes advanced information retrieval techniques. It operates by searching PubMed for specific queries, extracting and analyzing information relevant to the biomedical field. This system is designed to discern and illustrate relationships between biomedical entities obtained from automated information extraction. RESULTS: The implementation of GPDMiner demonstrates its efficacy in navigating the extensive corpus of biomedical literature. It efficiently retrieves, extracts, and analyzes information, highlighting significant connections between genes, proteins, and diseases. The platform also allows users to save their analytical outcomes in various formats, including Excel and images. CONCLUSION: GPDMiner offers a notable additional functionality among the array of text mining tools available for the biomedical field. This tool presents an effective solution for researchers to navigate and extract relevant information from the vast unstructured texts found in biomedical literature, thereby providing distinctive capabilities that set it apart from existing methodologies. Its application is expected to greatly benefit researchers in this domain, enhancing their capacity for knowledge discovery and data management.


Subject(s)
Data Management , Data Mining , Databases, Factual , Knowledge Discovery , PubMed
2.
Cell Death Dis ; 14(12): 788, 2023 12 01.
Article in English | MEDLINE | ID: mdl-38040710

ABSTRACT

Mitochondrial dysfunction is important in various chronic degenerative disorders, and aberrant immune responses elicited by cytoplasmic mitochondrial DNA (mtDNA) may be related. Here, we developed mtDNA-targeted MTERF1-FokI and TFAM-FokI endonuclease systems to induce mitochondrial DNA double-strand breaks (mtDSBs). In these cells, the mtDNA copy number was significantly reduced upon mtDSB induction. Interestingly, in cGAS knockout cells, synthesis of interferon ß1 and interferon-stimulated gene was increased upon mtDSB induction. We found that mtDSBs activated DNA-PKcs and HSPA8 in a VDAC1-dependent manner. Importantly, the mitochondrial E3 ligase MARCH5 bound active DNA-PKcs in cells with mtDSBs and reduced the type І interferon response through the degradation of DNA-PKcs. Likewise, mitochondrial damage caused by LPS treatment in RAW264.7 macrophage cells increased phospho-HSPA8 levels and the synthesis of mIFNB1 mRNA in a DNA-PKcs-dependent manner. Accordingly, in March5 knockout macrophages, phospho-HSPA8 levels and the synthesis of mIFNB1 mRNA were prolonged after LPS stimulation. Together, cytoplasmic mtDNA elicits a cellular immune response through DNA-PKcs, and mitochondrial MARCH5 may be a safeguard to prevent persistent inflammatory reactions.


Subject(s)
Lipopolysaccharides , Ubiquitin-Protein Ligases , Humans , Ubiquitin-Protein Ligases/metabolism , Lipopolysaccharides/metabolism , Membrane Proteins/metabolism , Mitochondria/metabolism , DNA, Mitochondrial/genetics , DNA, Mitochondrial/metabolism , Interferons/metabolism , RNA, Messenger/metabolism
3.
Sci Rep ; 13(1): 18884, 2023 11 02.
Article in English | MEDLINE | ID: mdl-37919369

ABSTRACT

Exposure to particulate matter (PM) causes mitochondrial dysfunction and lung inflammation. The cyclooxygenase-2 (COX-2) pathway is important for inflammation and mitochondrial function. However, the mechanisms by which glucocorticoid receptors (GRs) suppress COX-2 expression during PM exposure have not been elucidated yet. Hence, we examined the mechanisms underlying the dexamethasone-mediated suppression of the PM-induced COX-2/prostaglandin E2 (PGE2) pathway in A549 cells. The PM-induced increase in COX-2 protein, mRNA, and promoter activity was suppressed by glucocorticoids; this effect of glucocorticoids was antagonized by the GR antagonist RU486. COX-2 induction was correlated with the ability of PM to increase reactive oxygen species (ROS) levels. Consistent with this, antioxidant treatment significantly abolished COX-2 induction, suggesting that ROS is involved in PM-mediated COX-2 induction. We also observed a low mitochondrial membrane potential in PM-treated A549 cells, which was reversed by dexamethasone. Moreover, glucocorticoids significantly enhanced Bcl-2/GR complex formation in PM-treated A549 cells. Glucocorticoids regulate the PM-exposed induction of COX-2 expression and mitochondrial dysfunction and increase the interaction between GR and Bcl-2. These findings suggest that the COX-2/PGE2 pathway and the interaction between GR and Bcl-2 are potential key therapeutic targets for the suppression of inflammation under PM exposure.


Subject(s)
Dexamethasone , Glucocorticoids , Humans , Glucocorticoids/pharmacology , Glucocorticoids/metabolism , Cyclooxygenase 2/genetics , Cyclooxygenase 2/metabolism , Dexamethasone/pharmacology , A549 Cells , Particulate Matter/toxicity , Dinoprostone/metabolism , Reactive Oxygen Species , Inflammation
4.
EMBO J ; 42(19): e113481, 2023 10 04.
Article in English | MEDLINE | ID: mdl-37575012

ABSTRACT

The NLRP3 inflammasome plays a key role in responding to pathogens, and endogenous damage and mitochondria are intensively involved in inflammasome activation. The NLRP3 inflammasome forms multiprotein complexes and its sequential assembly is important for its activation. Here, we show that NLRP3 is ubiquitinated by the mitochondria-associated E3 ligase, MARCH5. Myeloid cell-specific March5 conditional knockout (March5 cKO) mice failed to secrete IL-1ß and IL-18 and exhibited an attenuated mortality rate upon LPS or Pseudomonas aeruginosa challenge. Macrophages derived from March5 cKO mice also did not produce IL-1ß and IL-18 after microbial infection. Mechanistically, MARCH5 interacts with the NACHT domain of NLRP3 and promotes K27-linked polyubiquitination on K324 and K430 residues of NLRP3. Ubiquitination-defective NLRP3 mutants on K324 and K430 residues are not able to bind to NEK7, nor form NLRP3 oligomers leading to abortive ASC speck formation and diminished IL-1ß production. Thus, MARCH5-dependent NLRP3 ubiquitination on the mitochondria is required for NLRP3-NEK7 complex formation and NLRP3 oligomerization. We propose that the E3 ligase MARCH5 is a regulator of NLRP3 inflammasome activation on the mitochondria.


Subject(s)
Inflammasomes , NLR Family, Pyrin Domain-Containing 3 Protein , Animals , Mice , Inflammasomes/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Interleukin-18/metabolism , Ubiquitination , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/metabolism , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Caspase 1/metabolism
5.
Nucleic Acids Res ; 50(16): 9247-9259, 2022 09 09.
Article in English | MEDLINE | ID: mdl-35979947

ABSTRACT

Cells are constantly challenged by genotoxic stresses that can lead to genome instability. The integrity of the nuclear genome is preserved by the DNA damage response (DDR) and repair. Additionally, these stresses can induce mitochondria to transiently hyperfuse; however, it remains unclear whether canonical DDR is linked to these mitochondrial morphological changes. Here, we report that the abolition of mitochondrial fusion causes a substantial defect in the ATM-mediated DDR signaling. This deficiency is overcome by the restoration of mitochondria fusion. In cells with fragmented mitochondria, genotoxic stress-induced activation of JNK and its translocation to DNA lesion are lost. Importantly, the mitochondrial fusion machinery of MFN1/MFN2 associates with Sab (SH3BP5) and JNK, and these interactions are indispensable for the Sab-mediated activation of JNK and the ATM-mediated DDR signaling. Accordingly, the formation of BRCA1 and 53BP1 foci, as well as homology and end-joining repair are impaired in cells with fragmented mitochondria. Together, these data show that mitochondrial fusion-dependent JNK signaling is essential for the DDR, providing vital insight into the integration of nuclear and cytoplasmic stress signals.


Subject(s)
DNA Damage , DNA Repair , Humans , DNA Repair/genetics , Genomic Instability , Mitochondria/genetics , Signal Transduction/genetics
6.
Curr Biol ; 32(2): 398-411.e4, 2022 01 24.
Article in English | MEDLINE | ID: mdl-34906353

ABSTRACT

Animals detect and discriminate countless environmental chemicals for their well-being and survival. Although a single chemical can trigger opposing behavioral responses depending on its concentration, the mechanisms underlying such a concentration-dependent switching remain poorly understood. Here, we show that C. elegans exhibits either attraction or avoidance of the bacteria-derived volatile chemical dimethyl trisulfide (DMTS) depending on its concentration. This behavioral switching is mediated by two different types of chemosensory neurons, both of which express the DMTS-sensitive seven-transmembrane G protein-coupled receptor (GPCR) SRI-14. These two sensory neurons share downstream interneurons that process and translate DMTS signals via distinct glutamate receptors to generate the appropriate behavioral outcome. Thus, our results present one mechanism by which an animal connects two distinct types of chemosensory neurons detecting a common ligand to alternate downstream circuitry, thus efficiently switching between specific behavioral programs based on ligand concentration.


Subject(s)
Caenorhabditis elegans Proteins/metabolism , Caenorhabditis elegans , Receptors, Odorant/metabolism , Animals , Caenorhabditis elegans/physiology , Caenorhabditis elegans Proteins/genetics , Ligands , Receptors, G-Protein-Coupled/genetics , Sensory Receptor Cells
7.
PLoS Genet ; 17(7): e1009678, 2021 07.
Article in English | MEDLINE | ID: mdl-34260587

ABSTRACT

Animals can adapt to dynamic environmental conditions by modulating their developmental programs. Understanding the genetic architecture and molecular mechanisms underlying developmental plasticity in response to changing environments is an important and emerging area of research. Here, we show a novel role of cAMP response element binding protein (CREB)-encoding crh-1 gene in developmental polyphenism of C. elegans. Under conditions that promote normal development in wild-type animals, crh-1 mutants inappropriately form transient pre-dauer (L2d) larvae and express the L2d marker gene. L2d formation in crh-1 mutants is specifically induced by the ascaroside pheromone ascr#5 (asc-ωC3; C3), and crh-1 functions autonomously in the ascr#5-sensing ASI neurons to inhibit L2d formation. Moreover, we find that CRH-1 directly binds upstream of the daf-7 TGF-ß locus and promotes its expression in the ASI neurons. Taken together, these results provide new insight into how animals alter their developmental programs in response to environmental changes.


Subject(s)
Caenorhabditis elegans Proteins/metabolism , Cyclic AMP Response Element-Binding Protein/metabolism , Transcription Factors/metabolism , Transforming Growth Factor beta/metabolism , Adaptation, Physiological/genetics , Animals , Caenorhabditis elegans/genetics , Caenorhabditis elegans Proteins/genetics , Cell Cycle , Cell Growth Processes , Cyclic AMP Response Element-Binding Protein/physiology , Gene Expression/genetics , Gene Expression Regulation/genetics , Gene Expression Regulation, Developmental/genetics , Larva/genetics , Larva/growth & development , Pheromones/metabolism , Sensory Receptor Cells/metabolism , Signal Transduction/genetics , Transcription Factors/genetics , Transforming Growth Factor beta/genetics , Transforming Growth Factor beta/physiology
8.
Front Psychol ; 11: 589708, 2020.
Article in English | MEDLINE | ID: mdl-33362655

ABSTRACT

This study assessed the demographic characteristics of Koreans engaged in leisure sports activities during the COVID-19 pandemic and the differences in their preventive health behaviors and constraints on leisure activities. For this study, the demographic characteristics (gender, age, marital status, level of participation in leisure sports, years of participation, companions with whom individuals participating in these sports, type of space used for performing the sports, occupation, and average monthly income) of 544 leisure sport participants (men: 46.0%, women: 54.0%; average age: 36.8 and 33.5 years, respectively), who were recruited on a nationwide basis, were examined through an online survey. Then, comparisons between groups were performed using independent t-tests, one-way analysis of variance, and multivariate analysis of variance. Women who participated in both indoor and outdoor leisure sports showed higher adoption of health prevention behaviors than their male counterparts, and married individuals who participated in indoor leisure sports showed higher adoption of health prevention behaviors than unmarried participants. Moreover, individuals who participated in both indoor and outdoor leisure sports by themselves had many interpersonal constraints overall, and the group of married individuals who participated in indoor leisure sports showed structural constraints. In conclusion, leisure sports participants have adopted many health prevention behaviors during the COVID-19 pandemic, but this had led to some interpersonal constraints. These results indicate that, in the case of future pandemics, personal and institutional efforts will need to be made to promote participation in leisure sports and prevent excessive social isolation.

9.
Cell Signal ; 67: 109520, 2020 03.
Article in English | MEDLINE | ID: mdl-31881323

ABSTRACT

The mitochondrial antiviral signaling (MAVS) protein on the mitochondrial outer membrane acts as a central signaling molecule in the RIG-I-like receptor (RLR) signaling pathway by linking upstream viral RNA recognition to downstream signal activation. We previously reported that mitochondrial E3 ubiquitin ligase, MARCH5, degrades the MAVS protein aggregate and prevents persistent downstream signaling. Since the activated RIG-I oligomer interacts and nucleates the MAVS aggregate, MARCH5 might also target this oligomer. Here, we report that MARCH5 targets and degrades RIG-I, but not its inactive phosphomimetic form (RIG-IS8E). The MARCH5-mediated reduction of RIG-I is restored in the presence of MG132, a proteasome inhibitor. Upon poly(I:C) stimulation, RIG-I forms an oligomer and co-expression of MARCH5 reduces the expression of this oligomer. The RING domain of MARCH5 is necessary for binding to the CARD domain of RIG-I. In an in vivo ubiquitination assay, MARCH5 transfers the Lys 48-linked polyubiquitin to Lys 193 and 203 residues of RIG-I. Thus, dual targeting of active RIG-I and MAVS protein oligomers by MARCH5 is an efficient way to switch-off RLR signaling. We propose that modulation of MARCH5 activity might be beneficial for the treatment of chronic immune diseases.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , DEAD Box Protein 58/metabolism , Immunity, Innate , Membrane Proteins/metabolism , Mitochondria/metabolism , Receptors, Immunologic/metabolism , Ubiquitin-Protein Ligases/metabolism , Ubiquitin/metabolism , Animals , DEAD Box Protein 58/chemistry , HEK293 Cells , Humans , Lysine/metabolism , Mice , Protein Binding , Protein Domains , Proteolysis , RAW 264.7 Cells , Receptors, Immunologic/chemistry , Ubiquitination
10.
Cell Death Dis ; 10(12): 938, 2019 12 09.
Article in English | MEDLINE | ID: mdl-31819032

ABSTRACT

Infection of hepatitis B virus (HBV) increase the incidence of chronic liver disease and hepatocellular carcinoma (HCC). The hepatitis B viral x (HBx) protein encoded by the HBV genome contributes to the pathogenesis of HCC and thus, negative regulation of HBx is beneficial for the alleviation of the disease pathogenesis. MARCH5 is a mitochondrial E3 ubiquitin ligase and here, we show that high MARCH5 expression levels are correlated with improved survival in HCC patients. MARCH5 interacts with HBx protein mainly accumulated in mitochondria and targets it for degradation. The N-terminal RING domain of MARCH5 was required for the interaction with HBx, and MARCH5H43W lacking E3 ligase activity failed to reduce HBx protein levels. High expression of HBx results in the formation of protein aggregates in semi-denaturing detergent agarose gels and MARCH5 mediates the elimination of protein aggregates through the proteasome pathway. HBx-induced ROS production, mitophagy, and cyclooxygenase-2 gene expression were suppressed in the presence of high MARCH5 expression. These results suggest MARCH5 as a target for alleviating HBV-mediated liver disease.


Subject(s)
Carcinoma, Hepatocellular/metabolism , Hepatitis B virus/chemistry , Hepatitis B/metabolism , Liver Neoplasms/metabolism , Membrane Proteins/metabolism , Protein Aggregates , Proteolysis , Trans-Activators/metabolism , Ubiquitin-Protein Ligases/metabolism , Viral Regulatory and Accessory Proteins/metabolism , Carcinoma, Hepatocellular/etiology , Carcinoma, Hepatocellular/mortality , Carcinoma, Hepatocellular/pathology , HEK293 Cells , HeLa Cells , Hepatitis B/complications , Hepatitis B/virology , Humans , Liver Neoplasms/etiology , Liver Neoplasms/mortality , Liver Neoplasms/pathology , Membrane Proteins/genetics , Mitochondria/metabolism , Protein Aggregation, Pathological/metabolism , Survival Rate , Transfection , Ubiquitin-Protein Ligases/genetics
11.
Nucleic Acids Res ; 47(12): 6299-6314, 2019 07 09.
Article in English | MEDLINE | ID: mdl-31045206

ABSTRACT

Histone H2AX undergoes a phosphorylation switch from pTyr142 (H2AX-pY142) to pSer139 (γH2AX) in the DNA damage response (DDR); however, the functional role of H2AX-pY142 remains elusive. Here, we report a new layer of regulation involving transcription-coupled H2AX-pY142 in the DDR. We found that constitutive H2AX-pY142 generated by Williams-Beuren syndrome transcription factor (WSTF) interacts with RNA polymerase II (RNAPII) and is associated with RNAPII-mediated active transcription in proliferating cells. Also, removal of pre-existing H2AX-pY142 by ATM-dependent EYA1/3 phosphatases disrupts this association and requires for transcriptional silencing at transcribed active damage sites. The following recovery of H2AX-pY142 via translocation of WSTF to DNA lesions facilitates transcription-coupled homologous recombination (TC-HR) in the G1 phase, whereby RAD51 loading, but not RPA32, utilizes RNAPII-dependent active RNA transcripts as donor templates. We propose that the WSTF-H2AX-RNAPII axis regulates transcription and TC-HR repair to maintain genome integrity.


Subject(s)
Histones/metabolism , Recombinational DNA Repair , Transcription Factors/metabolism , Transcription, Genetic , Cell Line, Tumor , DNA-Binding Proteins/metabolism , G1 Phase/genetics , HEK293 Cells , HeLa Cells , Histones/chemistry , Humans , Intracellular Signaling Peptides and Proteins/metabolism , Nuclear Proteins/metabolism , Phosphorylation , Protein Tyrosine Phosphatases/metabolism , RNA Polymerase II/metabolism , Tyrosine/metabolism
12.
Oncotarget ; 6(30): 29060-75, 2015 Oct 06.
Article in English | MEDLINE | ID: mdl-26334958

ABSTRACT

TRIP-Br1 oncogenic protein has been shown to have multiple biological functions in cells. In this study, we demonstrate that TRIP-Br1 functions as an oncoprotein by inhibiting autophagy, apoptosis, and necroptosis of cancer cells and eventually helping them to survive under the nutrient/serum starved condition. TRIP-Br1 expression level was significantly increased in conditions with low levels of nutrients. Nutrient depleted conditions were induced by culturing cancer cells until they were overcrowded with high cell density or in media deprived of glucose, amino acids, or serum. Among them, serum starvation significantly enhanced the expression of TRIP-Br1 only in all tested breast cancer cell lines (MCF7, MDA-MB-231, T47D, MDA-MB-435, Hs578D, BT549, and MDA-MB-435) but not in the three normal cell lines (MCF10A, HfCH8, and NIH3T3). As compared with the control cells, the introduction of TRIP-Br1 silencing siRNA into MCF7 and MDA-MB-231 cells accelerated cell death by inducing apoptosis and necroptosis. In this process, TRIP-Br1 confers resistance to serum starvation-induced cell deaths by stabilizing the XIAP protein and inhibiting cellular ROS production. Moreover, our data also show that the intracellular increase of TRIP-Br1 protein resulting from serum starvation seems to occur in part through the blockage of PI3K/AKT signaling pathway.


Subject(s)
Amino Acids/deficiency , Apoptosis , Autophagy , Breast Neoplasms/metabolism , Glucose/deficiency , Nuclear Proteins/metabolism , Trans-Activators/metabolism , Animals , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Survival , Culture Media, Serum-Free/metabolism , Female , Gene Expression Regulation, Neoplastic , Humans , MCF-7 Cells , Mice , NIH 3T3 Cells , Necrosis , Nuclear Proteins/genetics , Phosphatidylinositol 3-Kinase/metabolism , Proto-Oncogene Proteins c-akt/metabolism , RNA Interference , Reactive Oxygen Species/metabolism , Signal Transduction , Time Factors , Trans-Activators/genetics , Transcription Factors , Transfection , X-Linked Inhibitor of Apoptosis Protein/metabolism
13.
Nat Commun ; 6: 7821, 2015 Jul 22.
Article in English | MEDLINE | ID: mdl-26199140

ABSTRACT

DOT1L has emerged as an anticancer target for MLL-associated leukaemias; however, its functional role in solid tumours is largely unknown. Here we identify that DOT1L cooperates with c-Myc and p300 acetyltransferase to epigenetically activate epithelial-mesenchymal transition (EMT) regulators in breast cancer progression. DOT1L recognizes SNAIL, ZEB1 and ZEB2 promoters via interacting with the c-Myc-p300 complex and facilitates lysine-79 methylation and acetylation towards histone H3, leading to the dissociation of HDAC1 and DNMT1 in the regions. The upregulation of these EMT regulators by the DOT1L-c-Myc-p300 complex enhances EMT-induced breast cancer stem cell (CSC)-like properties. Furthermore, in vivo orthotopic xenograft models show that DOT1L is required for malignant transformation of breast epithelial cells and breast tumour initiation and metastasis. Clinically, DOT1L expression is associated with poorer survival and aggressiveness of breast cancers. Collectively, we suggest that cooperative effect of DOT1L and c-Myc-p300 is critical for acquisition of aggressive phenotype of breast cancer by promoting EMT/CSC.


Subject(s)
Breast Neoplasms/etiology , E1A-Associated p300 Protein/metabolism , Epigenesis, Genetic , Epithelial-Mesenchymal Transition , Methyltransferases/metabolism , Proto-Oncogene Proteins c-myc/metabolism , Animals , Breast Neoplasms/metabolism , Case-Control Studies , Cell Line, Tumor , Disease Progression , Female , Histone-Lysine N-Methyltransferase , Humans , Mice, Inbred NOD , Mice, SCID , Neoplasm Metastasis , Neoplastic Stem Cells/metabolism
14.
Adv Healthc Mater ; 4(2): 255-63, 2015 Jan 28.
Article in English | MEDLINE | ID: mdl-25044601

ABSTRACT

Here, wire-framed Au nanobundles (WNBs), which consist of randomly oriented and mutually connected Au wires to form a bundle shape, are synthesized. In contrast to conventional nanoparticles (spheres, rods, cubes, and stars), which exhibit nanostructure only on the surface, cross-sectional view image shows that WNBs have nanostructures in a whole volume. By using this specific property of WNBs, an externally controllable multistep photothermic-driven drug release (PDR) system is demonstrated for in vivo cancer treatment. In contrast to conventional nanoparticles that encapsulate a drug on their surface, WNBs preserve the drug payload in the overall inner volume, providing a drug loading capacity sufficient for cancer therapy. An improved in vivo therapeutic efficacy of PDR therapy is also demonstrated by delivering sufficient amount of drugs to the target tumor region.


Subject(s)
Drug Delivery Systems/methods , Gold/chemistry , Light , Metal Nanoparticles/chemistry , Temperature , Absorption, Physicochemical , Animals , Cell Line, Tumor , Humans , Metal Nanoparticles/ultrastructure , Mice, Inbred BALB C , Mice, Nude , Microscopy, Fluorescence , Spectroscopy, Near-Infrared
15.
Biomed Opt Express ; 5(8): 2837-42, 2014 Aug 01.
Article in English | MEDLINE | ID: mdl-25136506

ABSTRACT

We demonstrated that tumors in freshly excised whole brain tissue could be differentiated clearly from normal brain tissue using a reflection-type terahertz (THz) imaging system. THz binary images of brain tissues with tumors indicated that the tumor boundaries in the THz images corresponded well to those in visible images. Grey and white-matter regions were distinguishable owing to the different distribution of myelin in the brain tissue. THz images corresponded closely with magnetic resonance imaging (MRI) results. The MRI and hematoxylin and eosin-stained microscopic images were investigated to account for the intensity differences in the THz images for fresh and paraffin-embedded brain tissue. Our results indicated that the THz signals corresponded to the cell density when water was removed. Thus, THz imaging could be used as a tool for label-free and real-time imaging of brain tumors, which would be helpful for physicians to determine tumor margins during brain surgery.

16.
Nanotechnology ; 25(27): 275102, 2014 Jul 11.
Article in English | MEDLINE | ID: mdl-24960226

ABSTRACT

In this study, we developed the maleimidyl magnetic nanoplatform, which enables functional targeting of a biomarker-specific moiety for molecular imaging via MRI. The maleimide group of the maleimidyl magnetic nanoplatform is conjugated with a thiol group without additional crosslinkers and side products. A physicochemical analysis was conducted to verify the effectiveness of the maleimidyl magnetic nanoplatform, and the existence of the maleimidyl group was investigated using the platform. To prepare biomarker-specific MRI probes, a thiolated aptamer and peptide were immobilized onto the maleimidyl group of the maleimidyl magnetic nanoplatform. The fabricated MRI probes were applied to four cancer cell lines: HT1080, MCF7, MKN45, and HEK293T. To investigate the potential of the molecular MRI probe, the target-biomarker specificity was confirmed without serious cytotoxicity, and in vivo MRI analysis using a xenograft mouse model was demonstrated. We believe these results will be useful for fabricating molecular MRI probes for the diagnosis of cancer.


Subject(s)
Magnetic Resonance Imaging/instrumentation , Magnetite Nanoparticles/chemistry , Maleimides/chemistry , Maleimides/chemical synthesis , Nanotechnology/instrumentation , Neoplasms/diagnosis , Animals , Biomarkers/chemistry , Cell Survival/drug effects , HEK293 Cells , Humans , MCF-7 Cells , Magnetic Phenomena , Male , Mice , Mice, Inbred BALB C
18.
J Biomed Opt ; 19(5): 051203, 2014 May.
Article in English | MEDLINE | ID: mdl-24297058

ABSTRACT

Biomarker-specific photothermal nanoparticles that can efficiently sense markers that are overexpressed in distinguished adenocarcinomas have attracted much interest in an aspect of efficacy increase of cancer treatment. We demonstrated a promising prospect of a smart photothermal therapy agent employing anti-epidermal growth factor receptor aptamer (AptEGFR)-conjugated polyethylene glycol (PEG) layted gold nanorods (AptEGFR-PGNRs). The cetyltrimethylammonium bromide bilayer on GNRs was replaced with heterobifunctional PEG (COOH-PEG-SH) not only to serve as a biocompatible stabilizer and but also to conjugate AptEGFR. Subsequently, to direct photothermal therapy agent toward epithelial cancer cells, the carboxylated PEGylated GNRs (PGNRs) were further functionalized with AptEGFR using carbodiimide chemistry. Then, to assess the potential as biomarker-specific photothermal therapy agent of synthesized AptEGFR-PGNRs, the optical properties, biocompatibility, colloidal stability, binding affinity, and epicellial cancer cell killing efficacy in vitro/in vivo under near-infrared laser irradiation were investigated. As a result, AptEGFR-PGNRs exhibit excellent tumor targeting ability and feasibility of effective photothermal ablation cancer therapy.


Subject(s)
Aptamers, Nucleotide/chemistry , ErbB Receptors/genetics , Gold/chemistry , Nanotubes/chemistry , Phototherapy/methods , Animals , Aptamers, Nucleotide/genetics , Cell Line, Tumor , Cell Survival/drug effects , ErbB Receptors/metabolism , Gold/pharmacology , Humans , Male , Mice , Mice, Nude , Neoplasms, Glandular and Epithelial/metabolism , Xenograft Model Antitumor Assays
19.
Opt Express ; 21(18): 21299-305, 2013 Sep 09.
Article in English | MEDLINE | ID: mdl-24104004

ABSTRACT

We demonstrate the use of a THz penetration-enhancing agent (THz-PEA) to enhance the terahertz (THz) wave penetration depth in tissues. The THz-PEA is a biocompatible material having absorption lower than that of water, and it is easily absorbed into tissues. When using glycerol as a THz-PEA, the peak value of the THz signal which was transmitted through the fresh tissue and reflected by a metal target, was almost doubled compared to that of tissue without glycerol. THz time-of-flight imaging (B-scan) was used to display the sequential glycerol delivery images. Enhancement of the penetration depth was confirmed after an artificial tumor was located below fresh skin. We thus concluded that the THz-PEA technique can potentially be employed to enhance the image contrast of the abnormal lesions below the skin.


Subject(s)
Image Enhancement , Terahertz Imaging/methods , Animals , Ethanol/chemistry , Glycerol/chemistry , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasms/diagnosis , Petrolatum/chemistry , Time Factors , Water/chemistry
20.
J Biomed Opt ; 18(10): 107008, 2013 Oct.
Article in English | MEDLINE | ID: mdl-24165743

ABSTRACT

We show that terahertz (THz) time-domain spectroscopy (TDS) can be used to characterize the blood. The complex optical constants of blood and its constituents, such as water, plasma, and red blood cells (RBCs), were obtained in the THz frequency region. The volume percentage of RBCs in blood was extracted and compared with the conventional RBC counter results. The THz absorption constants are shown to vary linearly with the RBC concentration in both normal saline and whole blood. The excellent linearity between the THz signal and the RBC concentration was also confirmed in a polyurethane resin tube using a THz imaging method. These results demonstrate that THz-TDS imaging can facilitate the quantitative analysis of blood.


Subject(s)
Erythrocytes/chemistry , Hematologic Tests/methods , Plasma/chemistry , Terahertz Spectroscopy/methods , Absorption , Animals , Male , Rats , Rats, Sprague-Dawley , Refractometry
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