Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Series Title
      Series Title
      Clear All
      Series Title
  • Item Type
      Item Type
      Clear All
      Item Type
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Is Full-Text Available
    • Subject
    • Publisher
    • Source
    • Language
    • Place of Publication
    • Contributors
110 result(s) for "Kim, Hyun-Yi"
Sort by:
Identification of exosomal microRNA panel as diagnostic and prognostic biomarker for small cell lung cancer
Background Small cell lung cancer (SCLC) has an exceptionally poor prognosis; as most of the cases are initially diagnosed as extensive disease with hematogenous metastasis. Therefore, the early diagnosis of SCLC is very important and may improve its prognosis. Methods To investigate the feasibility of early diagnosis of SCLC, we examined exosomal microRNAs (miRNAs) present in serum obtained from patients with SCLC. First, exosomes were isolated in serum from patients with SCLC and healthy individuals and were characterized using particle size and protein markers. Additionally, miRNA array was performed to define SCLC-specific exosomal miRNAs. Second, the obtained miRNAs were further validated employing a large cohort. Finally, the ability to diagnose SCLC was estimated by area under the curve (AUC), and intracellular mRNA change patterns were verified through validated miRNAs. Results From the miRNA array results, we selected 51-miRNAs based on p-values and top 10 differentially expressed genes, and 25-miRNAs were validated using quantitative reverse transcription-polymerase chain reaction. The 25-miRNAs were further validated employing a large cohort. Among them, 7-miRNAs showed significant differences. Furthermore, 6-miRNAs (miR-3565, miR-3124-5p, miR-200b-3p, miR-6515, miR-3126-3p and miR-9-5p) were up-regulated and 1-miRNA (miR-92b-5p) was down-regulated. The AUC value of each miRNA sets between 0.64 and 0.76, however the combined application of 3-miRNAs (miR-200b-3p, miR-3124-5p and miR-92b-5p) remarkably improved the diagnostic value (AUC = 0.93). Gene ontology analysis revealed that the 3-miRNA panel is linked to various oncogene pathways and nervous system development. When the 3-miRNAs were introduced to cells, the resulting changes in total mRNA expression strongly indicated the presence of lung diseases, including lung cancer. In addition, the 3-miRNA panel was significantly associated with a poorer prognosis, although individual miRNAs have not been validated as prognostic markers. Conclusion Our study identified SCLC-specific exosomal miRNAs, and the 3-miRNAs panel (miR-200b-3p, miR-3124-5p and miR-92b-5p) may serve as a diagnostic and prognostic marker for SCLC. Graphical abstract
Mast4 determines the cell fate of MSCs for bone and cartilage development
Mesenchymal stromal cells (MSCs) differentiation into different lineages is precisely controlled by signaling pathways. Given that protein kinases play a crucial role in signal transduction, here we show that Microtubule Associated Serine/Threonine Kinase Family Member 4 (Mast4) serves as an important mediator of TGF-β and Wnt signal transduction in regulating chondro-osteogenic differentiation of MSCs. Suppression of Mast4 by TGF-β1 led to increased Sox9 stability by blocking Mast4-induced Sox9 serine 494 phosphorylation and subsequent proteasomal degradation, ultimately enhancing chondrogenesis of MSCs. On the other hand, Mast4 protein, which stability was enhanced by Wnt-mediated inhibition of GSK-3β and subsequent Smurf1 recruitment, promoted β-catenin nuclear localization and Runx2 activity, increasing osteogenesis of MSCs. Consistently, Mast4 −/− mice demonstrated excessive cartilage synthesis, while exhibiting osteoporotic phenotype. Interestingly, Mast4 depletion in MSCs facilitated cartilage formation and regeneration in vivo. Altogether, our findings uncover essential roles of Mast4 in determining the fate of MSC development into cartilage or bone. Controlling fate decision of mesenchymal stromal cells (MSC) is important for their clinical application. Here the authors demonstrate that TGF-β-induced Mast4 suppression and Wnt-mediated Mast4 stabilization regulate MSC differentiation into cartilage and bone, respectively.
scRNA-seq analysis discovered suppression of immunomodulatory dependent inflammatory response in PMBCs exposed to silver nanoparticles
The assessment of AgNPs toxicity in vitro and in vivo models are frequently conflicting and inaccurate. Nevertheless, single cell immunological responses in a heterogenous environment have received little attention. Therefore, in this study, we have performed in-depth analysis which clearly revealed cellular-metal ion association as well as specific immunological response. Our study didn’t show significant population differences in PMBC between control and AgNPs group implying no toxicological response. To confirm it further, deep profiling identified differences in subsets and differentially expressed genes (DEGs) of monocytes, B cells and T cells. Notably, monocyte subsets showed significant upregulation of metallothionein (MT) gene expression such as MT1G , MT1X , MT1E , MT1A , and MT1F. On the other hand, downregulation of pro-inflammatory genes such as  IL1β and CCL3 in both CD16 + and CD16- monocyte subsets were observed. This result indicated that AgNPs association with monocyte subsets de-promoted inflammatory responsive genes suggesting no significant toxicity observed in AgNPs treated group. Other cell types such as B cells and T cells also showed negligible differences in their subsets suggesting no toxicity response. Further, AgNPs treated group showed upregulation of cell proliferation, ribosomal synthesis, downregulation of cytokine release, and T cell differentiation inhibition. Overall, our results conclude that treatment of AgNPs to PMBC cells didn’t display immunological related cytotoxicity response and thus motivate researchers to use them actively for biomedical applications.
Fine-tuning of epithelial taste bud organoid to promote functional recapitulation of taste reactivity
Taste stem/progenitor cells from posterior mouse tongues have been used to generate taste bud organoids. However, the inaccessible location of taste receptor cells is observed in conventional organoids. In this study, we established a suspension-culture method to fine-tune taste bud organoids by apicobasal polarity alteration to form the accessible localization of taste receptor cells. Compared to conventional Matrigel-embedded organoids, suspension-cultured organoids showed comparable differentiation and renewal rates to those of taste buds in vivo and exhibited functional taste receptor cells and cycling progenitor cells. Accessible taste receptor cells enabled the direct application of calcium imaging to evaluate the taste response. Moreover, suspension-cultured organoids can be genetically altered. Suspension-cultured taste bud organoids harmoniously integrated with the recipient lingual epithelium, maintaining the taste receptor cells and gustatory innervation capacity. We propose that suspension-cultured organoids may provide an efficient model for taste research, including taste bud development, regeneration, and transplantation.
Mast4 knockout shows the regulation of spermatogonial stem cell self-renewal via the FGF2/ERM pathway
Spermatogenesis is an important cellular differentiation process that produces the male gametes and remains active throughout the individual’s lifespan. Sertoli cell-only syndrome (SCO) refers to the dysfunction of the male reproductive system, including infertility. Accurate self-renewal of spermatogonial stem cells (SSCs) is essential to prevent SCO syndrome. This study investigated the role of microtubule-associated serine/threonine kinase family member 4 (MAST4) in spermatogenesis in mice. MAST4 was localized in Sertoli cells before puberty, providing a somatic niche for spermatogenesis in mice and MAST4 expression shifted to Leydig cells and spermatids throughout puberty. Mast4 knockout (KO) testes were reduced in size compared to wild-type testes, and germ cell depletion associated with an increase in apoptosis and subsequent loss of tubular structure were similar to the SCO phenotype. In addition, MAST4 phosphorylated the Ets-related molecule (ERM), specifically the serine 367 residue. The phosphorylation of ERM ultimately controls the transcription of ERM target genes related to SSC self-renewal. The expression of spermatogenesis-associated proteins was significantly decreased whereas Sertoli cell markers were increased in Mast4 KO testes, which was well-founded by RNA-sequencing analysis. Therefore, MAST4 is associated with the fibroblast growth factor 2 (FGF2)/ERM pathway and this association helps us explore the capacity of SSCs to maintain a vertebrate stem cell niche.
Mechanistic insights into epithelial-mesenchymal transition mediated cisplatin resistance in ovarian cancer
Epithelial-mesenchymal transition (EMT) is designated as one of the prime causes of chemoresistance in many cancers. In our previous study we established that cisplatin resistance in ovarian cancer (OC) is associated with EMT using sensitive OV90 cells and its resistant counterparts OV90CisR1 and OV90CisR2. In this study, we revealed through RNAseq analysis that ITGA1 can play essential part in EMT mediated cisplatin resistance in OC. We found large number of EMT related terms predominant in the top gene ontologies (GO). We also found Extracellular matrix (ECM) and actin cytoskeleton genes highly altered in the resistant cells. This was further confirmed by the protein-protein interaction (PPI) analysis where we identified that the core ECM components e.g., collagen, fibronectin, metalloproteases and integrins possessed most interactions. The pathway analysis revealed the Wnt signaling as the leading pathway. Since integrins have significant interaction with Wnt signaling, we focused our study on integrins among which, ITGA1, ITGA6, ITGA11 and ITGAV were primarily altered. We validated our results by western blotting and found that ITGA1 was highly expressed in resistant cells. Additionally, the high ABCA5 (efflux transporter) expression in resistant cells also supports the EMT proposition. The western blotting also revealed high β-catenin expression in resistant cells confirming the high Wnt signaling activity. Further, we induced xenograft tumors in nude mice. The histopathological analysis confirmed the aggressive nature of resistant tumors and showed the presence of necrotic core which could be implicated to EMT. Finally, the immunohistochemical staining confirmed the high protein expression in resistant tumor.
Natal factors influencing newborn’s oral microbiome diversity
The early microbiota of neonates is crucial for developing the postnatal immune system and establishing normal physiological, metabolic, and neurological functions. This study aimed to investigate the factors influencing the diversity of the neonatal oral microbiome, including mother-to-newborn microbial transmission. The study includes a prospective cohort comprising 73 mothers and 87 neonates and a retrospective cohort comprising 991 mothers and 1,121 neonates. Samples from the maternal cervix and neonatal gastric, bronchial, and oral cavities were analyzed using culture-based methods. Neonatal oral swab samples were also analyzed using 16S rRNA gene sequencing to characterize microbial diversity and composition. Similar genera were detected in the neonatal gastric, bronchial, and oral samples, and the neonatal gastric culture was the most similar to the maternal cervical culture. In addition to mother-to-newborn microbial transmission, various natal factors including birth type, birth weight, delivery mode, maternal chorioamnionitis, maternal diabetes and the presence of microbes in other sites influenced neonatal oral microbiome diversity. Among these factors, the birth type was the most significant, and preterm neonates exhibited decreased oral microbiome diversity, with fewer beneficial bacteria and more pathogens. These findings could serve as a baseline for research on the establishment of the oral microbiota in preterm neonates and its health implications.
Valproic Acid Induces Hair Regeneration in Murine Model and Activates Alkaline Phosphatase Activity in Human Dermal Papilla Cells
Alopecia is the common hair loss problem that can affect many people. However, current therapies for treatment of alopecia are limited by low efficacy and potentially undesirable side effects. We have identified a new function for valproic acid (VPA), a GSK3β inhibitor that activates the Wnt/β-catenin pathway, to promote hair re-growth in vitro and in vivo. Topical application of VPA to male C3H mice critically stimulated hair re-growth and induced terminally differentiated epidermal markers such as filaggrin and loricrin, and the dermal papilla marker alkaline phosphatase (ALP). VPA induced ALP in human dermal papilla cells by up-regulating the Wnt/β-catenin pathway, whereas minoxidil (MNX), a drug commonly used to treat alopecia, did not significantly affect the Wnt/β-catenin pathway. VPA analogs and other GSK3β inhibitors that activate the Wnt/β-catenin pathway such as 4-phenyl butyric acid, LiCl, and BeCl(2) also exhibited hair growth-promoting activities in vivo. Importantly, VPA, but not MNX, successfully stimulate hair growth in the wounds of C3H mice. Our findings indicate that small molecules that activate the Wnt/β-catenin pathway, such as VPA, can potentially be developed as drugs to stimulate hair re-growth.
Activation of Wnt signalling reduces the population of cancer stem cells in ameloblastoma
Objectives The treatment of ameloblastoma, an odontogenic epithelial tumour destroying jawbone, mainly depends on radical destructive resections. Other therapeutic options are limited by the characteristics of ameloblastoma, such as high recurrence rates and resistance to radiation and chemotherapy, which implies possible existence of cancer stem cells (CSCs) in ameloblastoma. Here, we identified a putative CSC population in immortalized and primary human ameloblastoma cells and examined possible therapeutic reagents to reduce the CSC population. Methods We investigated subpopulations of AM‐1 cell line and human ameloblastoma cells using immunocytochemistry and flow cytometry and the effects of Wnt signalling activators on the 2‐ and 3‐dimensional cultured ameloblastoma cells using molecular biological analyses. Result Among heterogenous ameloblastoma cells, small‐sized and round‐shaped cells were found to be proliferative and expressed a marker of dental epithelial stem cells, SRY‐box 2 (Sox2). Exogenous activation of Wnt signalling using glycogen synthase kinase 3β inhibitors, lithium chloride (LiCl) and valproic acid (VPA), increased the cell size and decreased proliferation of cells and expression of Sox2 in 2 dimensionally cultured AM‐1 and human primary ameloblastoma cells. Furthermore, the growth of 3 dimensionally cultured AM‐1 cells as suspended or embedded in gel was suppressed by treatment with Wnt signalling activators, VPA and CHIR99021, or antibodies to sclerostin, an antagonist of Wnt signalling. Conclusion We suggest that Wnt signalling activators are potential drug candidates to suppress CSCs in ameloblastoma. Ameloblastoma, a benign tumour of the odontogenic epithelium, presents significant recurrence rates and resistance to radiotherapy and chemotherapy, which compel patients to undergo radical resections, potentially causing surgical morbidity. In this study, we found that the exogenous activation of Wnt signalling using antibody (α‐SOST antibody) or chemicals (LiCl, VPA or CHIR9902) increases β‐catenin (β‐cat) in ameloblastoma, leading to an increase in β‐cathigh and Sox2‐ cells and decrease in β‐catlow and Sox2+ cells, the putative cancer stem cells (CSCs). This change of sub‐population in ameloblastoma results in the suppression of spheroid‐forming activity and invasiveness. The results suggest that Wnt signalling activators may serve as potential drug candidates to suppress CSCs in ameloblastoma.